JP2001045867A - Method for diagnosing crop - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for diagnosing crops by measuring the quantity of light reflected from the crops, which has a method for correcting the reflected light quantity so as not to cause a large error by the differences of the depression angle and view angle of a camera and by which the information of the crops can simply be measured in improved measurement accuracy. SOLUTION: This method for diagnosing crops comprises disposing a camera at a prescribed central depression angle θ to a field, imaging the field to obtain the quantity of light reflected from crops for each unit picture elements, determining an imaged area for each picture elements by the use of area functions comprising conversion valuables including the ground height h, picture element depression angle θ, picture element number and view angle ψof the camera, correcting the reflected light quantity with the determined imaged area, dividing the unit picture elements into prescribed areas, determining a reflection rate from a reflection light quantity and a standard reflection light quantity for each divided area, determining the crop information of a constant area as the first crop information from the determined reflection rate and the first crop relation equation preliminarily prepared for determining a crop information from a reflection rate, and then diagnosing the nutritive states of the field crops from the first crop information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for obtaining nutrition information of a crop by obtaining crop information such as nitrogen content of a crop from reflected light of a growing crop in a field, and in particular, correcting a reflected light quantity obtained for each of a plurality of pixels. About.

[0002]

2. Description of the Related Art As a first conventional method for obtaining crop information such as nitrogen content, leaf color value, nitrogen absorption amount, plant height or dry matter weight of a crop, a light receiving means such as a digital camera is used. The reference plate on which the crop has been applied and the unit field where the crop grows (or a part thereof) are photographed, and the reflected light amount of the reference plate and the field crop is acquired. From the obtained reflectance and the reflectance, the nitrogen content (nitrogen absorption, leaf color value, plant height, dry matter weight) from the reflectance to determine the nitrogen content of the crop (nitrogen absorption, (Leaf color value, plant height, dry matter weight) was determined, and the growth was diagnosed by comparing with the standard nitrogen amount at that time based on a growth day versus nitrogen amount curve. However, the amount of reflected light of the crop obtained from the field depends on the weather. Also, even if the weather can be corrected by the reference plate, the measurement orientation, wind, and planting density need to be under the same conditions as when a predetermined relational expression was created to obtain the nitrogen content from the reflectance. However, it is necessary to make corrections when these conditions are different, and it is difficult to say that all of them could be corrected just by calculating the reflectance with reference to the reference plate.In practice, the sun altitude, measurement direction, planting density or varieties were limited. The measurement was performed after the measurement.

[0003] As a second conventional method for obtaining crop information, light having a wavelength related to the crop information that increases or decreases based on the growth of the crop, for example, light ranging from a visible light region to a near-infrared region, is irradiated to the crop leaf. An apparatus for measuring the amount of leaf blade nitrogen from the received light amount obtained with respect to light having a wavelength related to crop information and crop information from the received light amount, for example, a nitrogen content relation formula predetermined to calculate the leaf nitrogen content. There is. This device can measure a large amount of leaf nitrogen in a field by measuring many of the leaf blades in the field. However, in order to accurately grasp the crop information of the entire field, detailed measurement over the entire field is indispensable, which is very troublesome.

[0004] In the nutrition diagnosis of crop leaves performed by the first conventional method, remote sensing is called.
When a relatively wide field is targeted, observation is performed from a considerable distance, so that there is no large difference in the area of the subject corresponding to one pixel of the camera. Therefore, the resolution of the camera did not differ from pixel to pixel. On the other hand, even in remote sensing performed very close to the subject, there was no large difference in the area of the subject corresponding to one pixel, and the measurement could be performed to the same extent as described above.

[0005]

In the first method, the measurement is simple but the information of the crop obtained from the field depends on the measurement position and the planting density. Therefore, it is difficult to say that the measurement method is simple but accurate. In addition, when shooting with the camera facing the field, the amount of reflected light obtained for each imaging element of the camera needs to be corrected depending on the angle of depression or angle of view of the camera with respect to the field or the position such as the front side and the side opposite the wide field. It is. The distance between the camera and the field, which is the subject, differs for each pixel, and the imaging area obtained for each pixel differs depending on the distance. Further, the angle of reflection varies depending on the depression angle, which affects the amount of reflected light. The second method has no limitation on the measurement and has higher measurement accuracy and is more advantageous than the first method. However, since the measurement is performed for each leaf of the crop and a large number of measurement points is required,
The difficulty is that it takes a lot of measurement time.

In the conventional remote sensing, the measurement is restricted under the condition that there is no large difference in the area of the subject for each pixel. This was because it facilitated the subsequent correction, but due to its limitations, the observation device became large in order to capture a wide range, and the measurement range became very small when performing very close, Multiple measurements were required.

[0007] From the above, in obtaining crop information by measuring the amount of reflected light of a crop, there is provided a method of correcting the crop so that a large error does not occur even if the camera is taken on the ground. It is an object of the present invention to provide a method for diagnosing a crop in which measurement of information is simple and measurement accuracy is improved.

[0008]

As a first method according to the present invention, a camera having a plurality of pixels is arranged at a predetermined central depression angle with respect to a field, an image of the field is taken, and the amount of reflected light of the crop leaves is reduced to a unit pixel. Obtained for each, the ground height of the camera, the pixel depression angle, the area function consisting of the conversion variables including the number of pixels and the angle of view to determine the imaging area per unit pixel, the reflected light amount per unit pixel area correction by the imaging area, A plurality of pixels are divided based on the photographing area of the unit pixel corresponding to the maximum area among the photographing areas obtained for each unit pixel, a reflectance is obtained from a reflected light amount and a reference reflected light amount for each segment, and the reflectance and And a first crop relation formula determined in advance to obtain crop information from reflectance, and obtains crop information of a certain area from the first crop information, and diagnoses the nutrition of field crops from the first crop information. To diagnose growing crops And a means for solving the more the problems.

In a second method according to the present invention, the first crop information is obtained by calculating the amount of reflected light and the reference reflection of a unit pixel which is smaller than or equal to a predetermined photographing area among the photographing areas obtained for each unit pixel. A first predetermined value for obtaining the reflectance from the light quantity and obtaining the crop information from the reflectance and the reflectance;
And the first crop information of a certain area is obtained from the crop relation formula.

In order to obtain first crop information in advance, it has been studied to obtain a first crop relational expression which is determined by obtaining a reflectance determined from a reflected light quantity of a crop and a reflected light quantity of a reference plate. In the present invention, when obtaining the first crop information, the first crop information is provided based on the photographing angle between a so-called digital camera and a field having a plurality of pixels provided for the field, for example, according to the ground height of the camera. Correcting the difference in the amount of light received due to the difference in the light receiving area for each pixel position of the camera where the shooting range of the pixel shot close and the shooting range of the pixel shot far away differ based on the angle of depression and the angle of view due to the camera structure The present invention provides a method for diagnosing a crop that can be used.

The difference in the photographing area with respect to the amount of received light obtained for each unit pixel is the height of the ground of the camera, the depression angle of each unit pixel, the number of pixels constituting the camera structure, and the aggregate of pixels. A specific (area) function for obtaining an area photographed for each unit pixel is determined by the secondary projection transformation based on a camera-specific coefficient such as an angle of view based on the size of the imaging element and the condenser lens. Therefore, taking the camera height and depression angle as variables, or adding a camera-specific coefficient to the variables, find the shooting area for each unit pixel, and divide the reflected light amount for each unit pixel by the shooting area for each unit pixel. The amount of reflected light for each unit pixel that is not affected by the area can be obtained. In other words, this makes it possible to realize a correction relating to the distance between the camera and its shooting location (front side and opposite side).

Further, in the present invention, the plurality of pixels are divided based on the photographing area of the unit pixel corresponding to the maximum area among the plurality of pixels. When the camera is directed to a field, the field area obtained with one pixel increases as the distance from the camera increases. Therefore, based on the maximum area of the field obtained by one pixel, other pixels are combined and divided so as to have the same area. That is, even if the number of pixels is different, the pixels are divided so that the field area is constant, and the amount of reflected light is obtained. The reference at this time was based on the maximum area of the field obtained by one pixel. Since the amount of reflected light in a certain area can be obtained,
Even if the field area obtained for each pixel is different, it can be divided into certain areas to obtain the amount of reflected light that is not affected by the resolution of the camera.

On the other hand, in the second method, among the photographing areas obtained for each unit pixel, the reflectance is determined from the amount of reflected light of a unit pixel having a predetermined photographing area or less and the reference amount of reflected light. When the camera is directed to a field, the field area obtained with one pixel increases as the distance from the camera increases. Therefore, the information of the pixel obtained by imaging a field area exceeding a predetermined area that is suitable for nutrition diagnosis of crop leaves is not adopted,
Only the information of the pixels that image the field area equal to or smaller than the predetermined area is adopted. Then, based on a predetermined area of the field area obtained by one pixel, other pixels are combined and divided so as to have the same area. That is, even if the number of pixels is different, the pixels are divided so that the field area is constant, and the amount of reflected light is obtained. The reference at this time was based on a predetermined field area. Since the amount of reflected light in a predetermined area can be obtained, even if the obtained field area differs for each pixel on the ground with a camera, this can be divided into a predetermined area to obtain a reflected light amount that is not affected by the resolution of the camera. Here, the predetermined area is a field area suitable for nutrition diagnosis of crop leaves, and is, for example, about 1 m ² to 5 m ² .

The ratio of the amount of reflected light of a certain area or a predetermined area obtained in this way to the amount of reference light reflected by the reference plate or the amount of reference light from the sun irradiating light is determined, and is defined as the reflection coefficient in the certain area or the predetermined area.

The reflectivity of a fixed area or a predetermined area obtained as described above is a reflectivity obtained by photographing a field from a ground with a camera, and the influence of the camera height, depression angle, or camera structure on the field. Based on the corrected reflectance and the reflectance of the crop leaf whose crop information is known, a first crop relational expression predetermined for obtaining the crop information from the reflectance is determined by multiple regression analysis. The first crop information of the crop leaves can be obtained from the first crop relational expression and the reflectance obtained by the above-described correction and calculation. Note that the number of wavelengths of the reflected light amount is not limited to one, and the reflected light amount at a wavelength necessary for obtaining crop information is measured. Therefore, an operation for determining the reflectance for each of a plurality of wavelengths is required. In obtaining each function or coefficient, the reflected light amounts at a plurality of wavelengths can be combined.

As a third method according to the present invention, a camera having a plurality of pixels is arranged at a predetermined central depression angle with respect to a field, the field is photographed, and the amount of reflected light of crop leaves is obtained for each unit pixel. The imaging area per unit pixel is obtained by an area function consisting of conversion variables including the viewing distance, the pixel depression angle, the number of pixels, and the angle of view, and the amount of reflected light per unit pixel is corrected by the imaging area to obtain an area. A plurality of pixels are divided based on the area of the unit pixel corresponding to the maximum area of the photographed area, the reflectance is obtained from the reflected light amount and the reference reflected light amount for each segment, and the crop information is obtained from the reflectance and the reflectance. The first crop-related equation is determined in advance to obtain crop information of a certain area from the first crop information, and the first crop information is used as the first crop information. Task It was a means to solve.

In the third method, the visual field distance is used instead of the depression angle used for the specific function in the first method. In other words, the difference in the photographing area with respect to the amount of received light obtained for each pixel is determined by the height of the ground of the camera, the visual field distance (distance between the pixel and the photographing point) for each pixel, and the number of pixels, which is the structure of the camera. A specific (area) function for obtaining an area photographed for each pixel is calculated by a secondary projective transformation based on a camera-specific coefficient such as an angle of view based on the size of a photographic element which is an aggregate of pixels and a condenser lens. Is determined. Therefore, by taking the camera's ground height and viewing distance as variables, or adding a camera-specific coefficient to the variables, the shooting area for each pixel is obtained, and the amount of reflected light for each pixel is divided by the shooting area for each pixel. The amount of reflected light for each pixel, which is not affected by the above, can be obtained. In other words, this makes it possible to realize a correction relating to the distance between the camera and the shooting location (front side and opposite side). Since the other pixels are divided so as to have a constant area based on the maximum area among the photographing areas of the unit pixels as in the first embodiment, the description will be omitted.

According to a fourth method of the present invention, a camera having a plurality of pixels is arranged at a predetermined central depression angle with respect to a field, and the field is photographed to obtain the amount of reflected light of crop leaves for each unit pixel. The photographing area of each unit pixel is obtained by an area function consisting of conversion variables including the camera viewing distance, the pixel depression angle, the number of pixels, and the angle of view, and the amount of reflected light per unit pixel is corrected for the area by the photographing area to obtain the unit area. A first crop which is determined in advance to obtain a reflectance from the reflected light amount of a unit pixel and a reference reflected light amount which is equal to or smaller than a predetermined imaging area in the obtained imaging area, and obtains crop information from the reflectance and the reflectance. Crop information of a certain area is obtained from the relational expression and used as first crop information, and the means for solving the above-mentioned problem is provided by a crop diagnosis method of diagnosing nutrition of a field crop based on the first crop information.

In the fourth method, the visual field distance is used instead of the depression angle used for the specific function in the second method. In other words, the difference in the photographing area with respect to the amount of received light obtained for each pixel is determined by the height of the ground of the camera, the visual field distance (distance between the pixel and the photographing point) for each pixel, and the number of pixels, which is the structure of the camera. A specific (area) function for obtaining an area photographed for each pixel is calculated by a secondary projective transformation based on a camera-specific coefficient such as an angle of view based on the size of a photographic element which is an aggregate of pixels and a condenser lens. Is determined. Therefore, by taking the camera's ground height and viewing distance as variables, or adding a camera-specific coefficient to the variables, the shooting area for each pixel is obtained, and the amount of reflected light for each pixel is divided by the shooting area for each pixel. The amount of reflected light for each pixel, which is not affected by the above, can be obtained. In other words, this makes it possible to realize a correction relating to the distance between the camera and the shooting location (front side and opposite side). Since it is the same as the above-described second method to adopt the pixels having the acquired field area equal to or smaller than the predetermined area and to divide the adopted pixels so as to have the predetermined area, the description thereof is omitted.

By the way, as a method for obtaining the second crop information, light having a wavelength related to the crop information which increases or decreases based on the growth of the crop, for example, light ranging from the visible light range to the near-infrared range is directly applied to the crop leaf blade. Irradiation, to calculate the leaf nitrogen amount from at least one of the reflected light amount or transmitted light amount obtained with respect to the light of the wavelength related to the crop information, and the crop information such as the leaf blade nitrogen amount is known crop leaf light amount The leaf nitrogen amount can be measured from a predetermined nitrogen amount relational expression. This device can measure a large amount of leaf nitrogen in a field by measuring many of the leaf blades in the field. Therefore,
It is effective to further correct the above-mentioned first crop information.

As a first crop diagnosis method for effectively combining and correcting the two useful techniques for obtaining the first crop information and the second crop information, the first crop diagnosis method obtained from each of the first crop information and the second crop information is obtained.
The difference between the first crop information and the second crop information, and correcting the first crop information according to the difference, not only errors due to weather change (weather, time, sun position) but also difficult so far. It is possible to correct an error caused by the cultivated change (measurement orientation, planting density). In particular, it is optimal to perform a nutrition diagnosis at a plurality of locations in the same field because the correction can be easily determined.

By storing the difference between the first crop information and the second crop information determined as described above,
If only the first crop information is obtained from the unknown crop of a certain area in the field where the first crop information is obtained, the first crop information can be corrected based on the first crop information and the difference, and planting can be performed. Not only can errors due to the density and the measurement direction be easily corrected, but also by having correction values, it can be realized as an apparatus, and the apparatus can be used as an easy crop diagnosis method.

In order to make a more strict correction from the first crop diagnosis method, the second crop diagnosis method is applied.
That is, the first crop information is obtained, the obtained first crop information is divided into a plurality of sections, at least two points of data are selected from the plurality of sections, and a crop of two points of data is selected. By obtaining the second crop information directly from the crop leaves in the same field, the correlation is clarified with the data of the two points of the first and second crop information to determine a correction relational expression, and based on this, a plurality of sections are defined. Can be obtained, a plurality of crop information can be obtained from a certain range in obtaining the correction relational expression, and the first crop information can be corrected over a wide range by the correction relational expression. .

As a third method for diagnosing crops, in a field exposed to natural light, the reflectance of light having a wavelength related to the crop information, which is increased or decreased by the growth of the crop, is measured from the crop in each of a plurality of plots. And a first crop relational expression determined in advance for obtaining crop information from the reflectance, and obtains the crop information for each section from the first crop information and stores it as the first crop information, and stores the first crop information for each stored section. The crop information of at least two sections is selected from the above, and light is irradiated to the crop leaf corresponding to the two sections of the field, and the light amount of at least one of the transmission and reflection of the wavelength related to the crop information that increases or decreases according to the growth of the crop is determined. Measuring and calculating the crop information of the two sections from the light quantity and a second crop relation formula determined in advance to determine the crop information from the light quantity, and storing the obtained crop information as second crop information; The second crop The correction conversion formula to be corrected based on the information is determined, the first crop information is corrected for each section by the correction conversion formula to obtain third crop information, and the nutrition information of the field crop is obtained based on the obtained third crop information. The method for diagnosing a crop may be a method for diagnosing the crop.

Unlike the second crop diagnosis method, the third method obtains information of a plurality of sections individually. By selecting data of at least two sections from the plurality of sections and obtaining the second crop information directly from the crop leaves of the same section as the crop of the data of the two sections, the second crop information of the first and second crop information is obtained. This is to clarify the correlation with point data and determine a correction relational expression, and based on this, correct all values in multiple sections, and to obtain multiple crop information from a wide range in obtaining the correction relational expression Can be obtained, and the first relation
Can be corrected over a wide range.

According to the second and third crop diagnosis methods, the first crop relation formula and the correction conversion formula determined as described above are stored, and the reflectance is calculated from the crop leaf of an unknown field. Measure,
Since the third crop information can be obtained by the first crop relation formula and the correction conversion formula, the above-described items can be realized as a device by storing the above-mentioned items in the storage unit of the control device and appropriately reading and calculating the same. It is possible to provide a device which not only enables crop diagnosis by the device but also improves measurement accuracy.

In the second and third crop diagnosis methods, any two sections selected from the plurality of sections are defined as sections indicating the maximum value and the minimum value in the first crop information. A straight line for correction conversion of the first crop information and the second crop information can be easily determined at two points, upper and lower, regardless of the remaining data.

Although various types of crop information can be supposed, it is optimal to use the leaf nitrogen content or leaf color value for performing a nutritional diagnosis of the crop. It can be understood from the fact that the suitability immediately appears.

In the first to third crop diagnostic methods, in order to measure the reflectance of light having a wavelength related to crop information that increases or decreases as the crop grows, the reflected light of the crop is captured by an image sensor comprising a plurality of pixels. , A pixel that receives reflected light corresponding to the crop is selected, and the reflectance is measured based on the received light data of the selected pixel to obtain a first crop information diagnosis method. Depending on the planting density and the size of the imaged target field, that is, whether it is within the unit field or about 1 square meter, the reflected light obtained from the imaging means by a digital camera etc. It is not necessarily the reflected light obtained from. That is, when viewed in pixel units, reflected light from other than crops, for example, reflected light from field soil may be included. Therefore, it is preferable to select only the pixels having the reflectance in the predetermined range and use the selected pixels as the reflected light obtained from the crop to obtain the first crop information based on the received light data.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A measuring apparatus according to the present invention will be described with reference to FIGS. Here, a rice crop will be described as an example. FIG. 1 shows an example in which a crop in the field 1 is imaged. Here, a camera 2 serving as a light receiving device for measuring the reflected light of the crop is installed toward the field 1 where the crop grows. The field 1 is naturally exposed to natural light. Further, a white reference plate 3 is installed in the field.

FIG. 2 is a simplified block diagram of the camera 2. The camera 2 has, for example, 240,000 pixels (600 × 4 pixels).
An area sensor 4 having a resolution of about 00) is provided. The camera 2 has a filter wheel 6 having a plurality of narrow-band filters 5. For example, the filter 5 is switched by rotating the filter wheel 6. Filter 5
Is received by the area sensor 4 via, for example, a condenser lens 7 as optical means. The filter wheel 6 is rotated by a stepping motor 9 driven and controlled by a control circuit 8. Further, the control circuit 8
Sends the light receiving signal of the sensor-4 to the data processing device 20.

Here, the filter 5 is, for example, 450, 550, 625, 650, 675, 700n having a wavelength in the visible light range.
m is appropriately selected. Also, the near infrared wavelength of 75
0, 850, 950 to 1300 nm. For these wavelengths, it is necessary to select a band that shows a characteristic change with a change in the nitrogen content or leaf color value of the crop leaves. Accordingly, the filter may use both the visible light region and the near infrared region, or may use only one of them. Note that the wavelength is not limited to the present embodiment. Although four filters are shown in FIG. 2, the filters are mounted according to the purpose and can be changed at any time, and the number of filters to be used is not limited. An operation switch 10 is further connected to the control circuit 8, and the operation switch 10 is a photographing start switch 10 for photographing.
a, a shooting stop switch 10b for stopping shooting, a filter changeover switch 10c for switching a filter,
It is provided with a data transmission switch 10d for transmitting photographing data, a power switch 10e, and the like.

FIG. 3 is a block diagram of the data processing device 20. A data processing device 20 shown in FIG. 3 is an analog-to-digital converter (hereinafter, referred to as an “A / D converter”) 21 that converts an image signal of the area sensor 4 into a digital signal.
And a frame memory 22 for storing the image data after A / D conversion, a monitor 23 for visually displaying the image data, and an image processing board 24. ) To a CPU 26 for performing arithmetic processing on image data. Further, a leaf blade nitrogen amount measuring device 30 described later is connected via an interface board (hereinafter, referred to as an “I / F board”) 27. Read-only memory (hereinafter, referred to as “ROM”) 28 further storing a control program and the like.
And a read / write memory (hereinafter, referred to as “RAM”) 29 that can store the operation result and the like and read it out as appropriate,
26.

When the power switch 10e of the camera 2 is pressed, the reflection signal of the image is received by the area sensor 4 to become an image signal, and this image signal is sent to the data processing device 20 by pressing the data transmission switch 10d. You. In the data processing device 20, the image data is processed by the image processing board 24 and displayed on the monitor 23. Monitor 2
In step 3, the position of the camera 2 is set while confirming the field 1, and the photographing range is determined. When the photographing range is determined, the photographing start switch 10 is passed through the currently set filter 5.
After pressing a, the leaves of rice growing in the field 1 are photographed, and then a signal for rotating the stepping motor 9 is output from the control circuit 8 by the filter changeover switch 10c, and the filter 5 is switched by rotating the filter wheel 6;
The photographing switch 10a is pressed to photograph. In this way, the photographing is performed for each required filter 5 while sequentially switching the filters 5. As a result, an image signal is created for each filter 5. Here, if the area sensor 4 of the camera 2 does not have a large-capacity storage element, the data transmission switch 10 transmits data to the data processing device 20 every time shooting is performed.
Press d.

The data of the unit pixel photographed by the camera 2 of the measuring device configured as described above is processed as follows. FIG. 4 is a diagram showing the ground height h, the depression angle θ, the angle of view ψ, the viewing distances l1, l2, and the like of the camera 2 when the field is photographed from the viewpoint 0 of the camera 2. FIG. 5A shows the pixel coordinates ij of the area sensor 4, and FIG. 5B shows the field area Aij acquired by the pixels. FIG.
As is apparent from the above, the field images acquired at the respective pixel coordinates ij have different areas. Therefore, even in the same field, the density of the information amount differs for each pixel coordinate ij. This is corrected by the following area function. The area function referred to here is a mathematical analysis method generally called a quadratic projection transformation, and therefore only its outline will be described. The following area function is established by the ground height h or the viewing distance l of the camera 2, the angle of depression θ of photographing, the angle of view で which is a coefficient unique to the camera 2, and the number of pixels.

(Depression angle) Aij = f (θ, h, i, j, x1, x2...) (Viewing distance) Aij = g (θ, 1, i, j, x1, x2...) Aij: pixel Field actual area acquired at coordinates ij, i, j: pixel coordinates x1: angle of view (camera specific) x2: number of pixels (camera specific) Thus, depression angle θ, ground height h or viewing distance l
, The actual area Aij for each pixel coordinate can be calculated. That is, the actual area can be obtained by either the field actual area formula 1 obtained based on the depression angle or the field actual area formula 1 obtained based on the viewing distance.

Here, assuming that the amount of received light (intensity) of the reflected light at the pixel coordinates ij is Pij

[Mathematical formula-see original document] P'ij = Pij / Aij, and the received light amount P acquired by the pixel ij with the actual area Aij
By dividing ij, it is possible to obtain the amount of reflected light per unit area that is not affected by the magnitude of the actual area of the field acquired at the pixel coordinates ij. As described above, the area correction can be performed for each pixel coordinate ij, and the amount of reflected light for each pixel coordinate ij that is not affected by the size of the actual area obtained by imaging is obtained. As described above, the area correction by the secondary projection conversion in the case where the image is taken at the predetermined ground height h or the viewing distance l and at the predetermined depression angle θ has been described.

Next, since the depression angle θ differs for each pixel coordinate ij, the depression angle correction accompanying θ is performed. As shown in FIG. 6, the reflected light of the reference plate or the crop leaf at the same position in the field is measured at the same distance. For example, the correction coefficient may be determined by changing the depression angle θ1 from the depression angle θ2, preferably based on the amount of reflected light at the pixel coordinates at the center of the area sensor 4. For example, when the depression angle θ is 60 °, the correction coefficient of the reflected light amount is K60 ° = 1.
If so,

Depression angle θ = 60 °: K60 ° = 1 Depression angle θ = 50 °: Reflection light amount at depression angle 50 ° / reflection light amount at depression angle 60 ° = Correction coefficient at depression angle 50 ° = K50 ° Depression angle θ = 40 °: Depression angle Reflection light amount at 40 ° / reflection light amount at 60 ° depression angle = Correction coefficient at 40 ° depression angle = K40 ゜ Depression angle θ = 10 °: Reflection light amount at 10 ° depression angle / reflection light amount at 60 ° depression angle = Correction coefficient at 10 ° depression angle = K10 ゜, the correction coefficient at each depression angle θ is determined, and the correction coefficient Kij for each pixel coordinate ij is determined. Therefore, by the P′ij obtained after the area correction and the correction coefficient Kij,

P′ij = Kij · P′ij, and the depression angle can be corrected by the depression angle θ.
The correction regarding the above has been described. In any case, in the area correction, a predetermined value (θ, h, l, etc.) is input in advance, or in the depression angle correction, the amount of reflected light is measured in advance at a plurality of depression angles θ, and a correction coefficient is set for each pixel coordinate. Kij
It is necessary to define

Next, the reflected light amount received by the area sensor 4 of the camera 2 is the reflected light amount of the reference plate 3 and the reflected light amount of the crop leaves in the field 1. When measuring the amount of reflected light from the reference plate 3, it is preferable to measure the amount of reflected light from the reference plate at a depression angle θ used as a reference in the depression angle correction, in the above example, at a depression angle of 60 °. Assuming that the reference plate reflected light amount measured in this way is P0,

Rij = P "ij / P0 Rij: The reflectance of rice leaves can be determined by the reflection coefficient for each pixel coordinate ij. This reflectance is used to determine the nitrogen content of rice leaves. These formulas 1 to 5 are stored in the ROM 28. The above-mentioned reference plate reflected light amount P0 is measured and stored as follows: The filter 5 provided in the camera 2 is switched and the reference is set for each filter. The amount of reflected light from the plate 3 is measured and sent to the data processing device 20.
9 is stored. That is, the value of the reference plate reflected light amount P0 is measured and stored for each filter 5.

The filter 5 is switched by the camera 2 and the amount of reflected light of the leaves of the rice in a certain area of the field 1 is received and transmitted to the data processor 20 for each filter. The signal is converted into a digital signal by 21 and stored in the frame memory 22. CPU26
Calculates the average value of the amount of light received by each pixel with respect to the amount of reflected light of the leaves of each filter 5 stored in the frame memory 22 and calculates the reflectance based on the above-described mathematical expression stored in the ROM 28 in advance. And store it in the RAM 29. This stores the reflectance of a certain range of the unit pixels, for example, the crop leaves in a range of one square meter.

FIGS. 7 and 8 show an example in which data of 240,000 pixels obtained by photographing crop leaves in the field 1 is further divided into a plurality of sections and processed. For example, the filter 5 is switched by the camera 2, and for each filter, the reflected light amount of the rice leaf in a certain area of the field 1 is received and transmitted to the data processing device 20. The signal is converted into a digital signal and stored in the frame memory 22. The CPU 26 determines the amount of reflected light of the leaves for each filter 5 stored in the frame memory 22.
As shown in FIG. 7, for example, sections NO to are determined from the upper left, an average value of the amount of light received by each pixel in the section is obtained, and each section is The reflectance is calculated and stored in the RAM 29. The image processed by the image processing board 24 is displayed on the monitor 23.

The division here is determined as follows. First, a first method of the division shown in FIG. 7 is based on the actual field area of the pixel (each in FIG. 7) showing the maximum value among the actual field areas Aij obtained by unit pixels by photographing the field. That is, with the maximum actual field area as a reference area, a plurality of adjacent pixels are combined to divide all the pixels so as to have a constant area. At this time, even if the unit pixel is further divided, the reflected light amount per unit area can be reflected on the divided area because the reflected light amount per unit area is obtained, so it is possible. It is assumed that the image data is divided as described above and divided into nine data for convenience. That is, it is assumed that each of the pixels at the top of FIG. 7 has the maximum real area, and the following pixels are divided into a certain area based on this real area. This shows that the area is constant. Actually, it is a more complicated division, but it is simply shown here. Here, it is preferable that the camera is arranged so that the fixed area is 1 m ² to 5 m ² and shooting is performed. Even if the unit is divided into smaller units, not only the information on the crop leaves is not reflected in all the reflected light amounts obtained for each pixel, but also the work efficiency is reduced due to the size of the crop leaves and the planting density. Conversely, if the sectional area is too large, the work efficiency will be improved, but the obtained information will be coarse and the accuracy will be reduced.

[0042] Next a second method of classification shown in FIG. 8, of the field actual area Aij obtained in a unit pixel by photographing a field, predetermined area, included in the pixel (segment-for example, it does not exceed 1 m ² ), And a plurality of adjacent pixels are combined with a predetermined area as a reference area to partition all the pixels so as to have a predetermined area. At this time, since the unit pixel is further divided and the amount of reflected light per unit area is obtained, the amount of reflected light per unit area can be reflected on the divided area. Here, it is assumed that the image is divided into nine sections for convenience. In FIG. 8, the uppermost three pixels are pixels that exceed a predetermined area and are excluded, and among the pixels having a certain area or less, the division is just a predetermined area, and is a predetermined area for three pixels. Indicates that a predetermined area is obtained for four pixels. Actually, it is a more complicated division, but it is simply shown here. Making the predetermined area 1 m ² means that even if the area is divided into smaller units, the size of crop leaves, planting density, etc.
Not only the information on the crop leaves is not reflected in all the reflected light amounts obtained for each pixel, but also the working efficiency is reduced. Conversely, if the sectional area is too large, the work efficiency will be improved, but the obtained information will be coarse and the accuracy will be reduced.

The RAM 29 has a plurality of filters 5.
The reflectance of the crop leaves within the light receiving range for each of the filters and the reflectance of each crop leaf processed into nine sections for each filter 5 are stored. The filter 5 stored in the RAM 29
By using the reflectance of each of the filters or the reflectance processed in 9 sections for each filter 5 as an explanatory variable, a leaf growing in the same light receiving range or in the same section is collected, and the crop information of the leaf, for example, The relationship between the direct chemical analysis of the nitrogen content or the leaf color value obtained by directly measuring the leaf color, and using the nitrogen content or the leaf color value as an objective variable to obtain the crop information of the crop leaf within the light receiving range. An equation and a relational equation (first crop relational equation) for obtaining the crop information of the crop leaves for each of the nine sections are created and stored in the ROM 28.

More specifically, if there is a reflectance R1 by the filter 1, a reflectance R2 by the filter 2, a reflectance R3 by the filter 3, and a reflectance R4 by the filter 4 in the section NO, the crop leaves in the section are chemically analyzed. When the nitrogen content N1 obtained by

Assuming that N1 = F0 + F1 · R1 + F2 · R2 + F3 · R3 + F4 · R4, a plurality of nitrogen contents N are measured.

N1 = F0 + F1 · R11 + F2 · R21 + F3 · R31 + F4 · R41 N2 = F0 + F1 · R12 + F2 · R22 + F3 · R32 + F4 · R42 · · · · · · Nn = F0 + F1 · R1n + F3 · R4n By regression analysis,

N = F0 + F1 · R1 + F2 · R2 + F3 · R3 + F4 · R4 + C N: Nitrogen content to be measured, F0 to F4: constant, R1 to R
4: Relational reflectance (first crop relational expression) can be obtained as the reflectance C for each filter. The relational expression can be similarly obtained for the leaf color value. This equation 8 is stored in the ROM 28.

If Equations 1 to 5 and Equation 8 are stored in the ROM 28 in this manner, the reference plate and the rice leaves in the light receiving area are photographed by the camera 2 and this image signal is processed by the data processor 20. To the data processing device 20
Then, the nitrogen content can be calculated based on the first crop relational expression. As a result, the nitrogen content of the rice within the light receiving range or the nitrogen content (first crop information) NO〜 of each section can be obtained. The numerical values described in each section in FIG. 7 are examples of the nitrogen content obtained at this time.

Next, an embodiment of the apparatus 30 for measuring the amount of nitrogen in the blade blade will be described with reference to FIGS. FIG. 1 is a side view in which a main part of a portable nitrogen amount measuring device (hereinafter referred to as “measuring device”) 30 is broken. FIGS. 9 and 10 show a configuration in which a light source unit 32 is provided in an upper body 31 and a photodiode (not shown) serving as a light amount detection device 33 is provided below. The light source unit 32 includes a plurality of light emitting elements LED3 having different wavelength peaks on the same circumference.
The LEDs 34 and 35 are provided with narrow band filters 36 and 37 having different wavelength bands. The wavelength band is preferably 500 nm to 1100 nm, and from this wavelength band, a narrow band filter 36 of any specific wavelength related to the required leaf nitrogen amount or leaf color value,
37 is selected. The light emitted from each of the LEDs 34 and 35 is converted into light of a specific wavelength by the narrow band filters 36 and 37, and is incident on the diffuse reflection plate 38 that reflects the light. A block 39 is formed so that the light beams of the LEDs 34 and 35 are incident on the diffuse reflection plate 38 at a substantially constant angle.

The light reflected by the diffuse reflection plate 38 enters a reflection light path 40 provided at the center of the block 39, and enters a diffusion transmission plate 42 provided on the radiation side 41 of the reflection light path 40. The diffuse reflection plate 42 is provided perpendicular to the optical axis of the reflection optical path 40 and is formed of a circular ground glass or milky white glass. In the space surrounded by the reflection light path 40 and the diffuse reflection plate 38, light exits the reflection light path 40 while repeating reflection and diffusion, and enters the light quantity detection device 44 through the diffusion transmission plate 42 and the measurement leaf 43. .

Further, an upper lid 31 is provided on the outer periphery of the upper part of the light amount detection device 32, and an arm 45 extending from the upper lid 31 is supported by a shaft 46. Further, a coil spring 47 is loosely fitted on a shaft 46 on which the upper lid 31 is supported, and acts so as to always push up the upper lid 31. That is, as shown in FIG. 11, in the measurement, the measurement is enabled by inserting the measurement leaf 43 into the measurement place and pressing down the upper part of the upper lid 31. At the timing of this measurement, it is detected that the push-down protrusion (not shown) provided below the upper cover 31 by pushing down the upper cover 31 pushes down the microswitch 48 provided at the opposing position, thereby pressing down the upper cover 31. (Light irradiation and light quantity measurement).

Next, a block diagram of the absorbance measuring device 1 will be described with reference to FIG. The transmitted light amount of the sample leaf 43 detected by the measuring unit including the light source unit 32 and the light amount detecting device 33 is converted into an analog signal by the light amount detecting device 44 and communicated to the analog board 50. The light source unit 32 is provided with a light emitting device 51 of LEDs 34 and 35. The analog board 50 performs A / D conversion from analog to digital signals or V / F conversion from voltage to frequency. The converted signal is input to a CPU board 53 serving as an arithmetic and control unit via an I / O board. The I / O board 52 includes a liquid crystal display LCD 54 for displaying a measurement result, a calculation result or an operation instruction, an input unit 55 for performing an operation, and an RS for inputting and outputting data to an external device.
A 232C connection port 56 and a switch 48 are provided. The CPU board 53 and the I / O board 52 are connected so that power is supplied from a power supply board 57. The printer 58 is connected to the CPU board 53 via a printer I / F board 59. Further, the CPU board 53 includes a read only memory (hereinafter referred to as “ROM”) 60 and a read / write memory (hereinafter referred to as “RAM”).
61) are connected. The ROM 60 stores a plurality of calibration curves for each field or each variety. This calibration curve calculates absorbance from a plurality of received light amounts obtained by irradiating light to a plurality of leaves whose nitrogen content has been measured in advance, and uses this absorbance as an explanatory variable, and a plurality of known nitrogen contents as objective variables. Is a relational expression (second crop relational expression) for performing a multiple regression analysis to obtain a predetermined nitrogen content rate (second crop information). The description of the multiple regression analysis will be omitted because the procedure for obtaining the above-described formulas is the same as that of the above-described procedure. Furthermore, this R
The OM 60 stores a series of programs for executing the calculation and display from the measurement of the absorbance for measuring the absorbance and calculating the quality such as the nitrogen content in the measuring device 30.

The operation of the measuring device 30 configured as described above will be described below. Sample leaf 4 in measuring device 30
3 is inserted and the upper lid 31 is pushed down, the signal of the switch 48 is communicated to the CPU board 53, and the CPU board 53
, A signal is output to the light emission control device 51, and a light emission signal is sent from the light emission control device 51 to the light source unit 32. Accordingly, light is alternately emitted from the LEDs 34 and 35 toward the sample leaves 43. The light emitted from the LEDs 34 and 35 is converted into light having a specific wavelength in the near-infrared region and visible light region by the narrow band filters 36 and 37. Since the sample leaves 43 are reached, the sample leaves 43 are evenly irradiated to the same extent as the integrating sphere.

When the sample leaves 43 are irradiated with light, the transmitted light or the reflected light is converted by the light amount detection device 44 into the LED 3.
Light is received every 4, 35, and the received light signal is transmitted to the analog board 50 for A / D conversion. The analog board 50 performs A / D conversion, and then inputs the data to the CPU board 53 via the I / O board 52. The CPU board 53 calculates the light transmittance or the absorbance from the transmitted light or the reflected light of the sample leaf 43, and the value is stored in the RAM 61. The measured nitrogen content of the leaf can be calculated from the absorbance stored in the RAM 61 and the relational expression for calculating the nitrogen content stored in the ROM 33 in advance. The input unit 55 includes a power switch 55a for turning on the power of the measuring device 30, a measurement switch 55b for enabling transmitted light measurement, a calibration curve (formula) stored in the ROM 60, and absorbance or transmitted light data stored in the RAM 61. A readout switch 55c having a switching function of reading out a calculation result, a sample number, and the like is provided.

Hereinafter, a first embodiment in which a nutrition diagnosis of a field crop is performed based on the first crop information and the second crop information will be described. The camera 2 measures the reflected light from the reference plate 3 and the amount of reflected light of a wavelength related to, for example, the nitrogen content, which is crop information that increases or decreases as the rice grows from the field 1 exposed to natural light. As shown in FIGS. 2 to 4, in the data processing device 20, the reflectance is calculated by the reflected light amount of the leaves within the light receiving range measured by the camera 2 and the formula for calculating the reflectance within the light receiving range stored in the ROM 28. Based on the calculated and calculated reflectance and the first crop relational expression stored in the ROM 28, the nitrogen content in the light receiving range of the camera 2 as the first crop information is obtained and stored in the RAM 29.

Next, the case where the nitrogen content of the rice leaves growing within the light receiving range of the camera 2 is measured and corrected will be described. The nitrogen content (second crop information) of the rice leaves measured by the device 30 is a measurement value obtained directly from the leaves of the rice, and is not affected by the measurement orientation, the planting density, and the like. Therefore, in the present invention, the difference between the first crop information and the second crop information is calculated. For example, if the first crop information is 4.0% in the previous measurement and the second crop information is 3.0% in the measurement of the device 30, the value of the device 30 is stored in the RAM 61 as the second crop information. I do. The second crop information obtained by the measuring device 30 is transmitted from the connection port 56 of the measuring device 30 via the I / F board of the data processing device 20 to the data processing device 20 and RA is output.
Store it in M29. The device 20 determines the first crop information based on the difference between the first crop information and the second crop information in the RAM 29, -1%.
-1% is added to the crop information of the above, and corrected to 3.0%.

In other words, this difference is stored again in the RAM 29 as a correction value, and the reflected light of the crop leaves in other light receiving ranges is measured by the camera 2 and the value calculated by the device 20 is as follows:
All are corrected by adding the difference -1%. Thereby, the measurement which is not affected by the measurement direction and the planting density can be realized by the camera 2 and the device 20. And RAM
After storing the correction value in 29, at least many measurements by the device 30 in the same field become unnecessary,
With one measurement by the camera 2, measurement can be performed with unprecedented accuracy. Note that the measurement of the nitrogen content by the measuring device 30 does not need to be performed for all the crop leaves in the field 1, but may be performed by measuring the nitrogen content of the representative crop leaves in the field 1.

Next, a second embodiment of the nutrition diagnosis will be described. The camera 2 measures the reflected light from the reference plate 3 and the amount of reflected light of a wavelength related to, for example, the nitrogen content, which is crop information that increases or decreases as the rice grows from the field 1 exposed to natural light. As shown in FIGS. 2 to 4, NO to NO measured by the camera 2 in the data processing device 20.
The reflectance is calculated by the reflected light amount divided into the sections and the formula for calculating the reflectance for each section stored in the ROM 28, and the calculated reflectance and the first crop relational expression stored in the ROM 28 are used to calculate the reflectance. The nitrogen content for each section, which is one crop information, is obtained and stored in the RAM 29.

Next, the nitrogen content of any two sections is selected from the values for each section obtained here by the operator or by the apparatus 20, and preferably, the nitrogen content becomes the maximum value and the minimum value. Select the parcel that has been set. 7 or 8, for example, a section of 4.2% of the maximum NO and a section of the field corresponding to the section of 2.4% of NO which is the minimum value of the rice leaves growing in the field section. The nitrogen content is measured by the measuring device 30. The nitrogen content measured here is not affected by the measurement orientation, planting density, and the like.

As described above, the measuring device 30 directly emits light having a wavelength related to the leaf nitrogen rate, which is crop information that increases or decreases as the crop grows, from the leaf blade of the rice corresponding to the two selected sections of the field. In this example, the amount of light received is converted into the absorbance from the amount of light obtained by irradiation, and the two divisions are calculated from the absorbance and a second crop-related equation predetermined to determine the leaf nitrogen rate from the absorbance. Is calculated. Then, the NO section is determined to be 3.0% and the NO7 section is determined to be 2.4%, and this value is stored in the RAM 61 as second crop information. The nitrogen content of the two compartments determined by the measuring device 30 is sent out to the data processing device 20 from the connection port 56 of the measuring device 30 via the I / F board of the data processing device 20 and R
Store it in AM29.

The first crop information (NO to NO nitrogen content) also stored in the RAM 29 is corrected for each section based on the nitrogen content of the two sections as the second crop information stored in the RAM 29. Using the third crop information will be described with reference to FIG. In FIG. 12, the horizontal axis represents the nitrogen content (second crop information) measured by the measurement device 30, and the vertical axis represents the nitrogen content (first crop information) calculated by the data processing device 20. FIG. That is, the nitrogen content of the two sections by the measuring device 30 is 3.0% and 2.4%.
And 4.2% of NO in two sections by the data processing device 20
FIG. 4 is a diagram created by using the NO and the nitrogen content of 3.6%. In this way, the straight line represented by a simple function consisting of the relationship between the nitrogen content of the two sections measured from the leaf blade of the rice by the measuring device 30 and the nitrogen content measured by the camera 2 is actually used. The relationship is clarified, and the nitrogen content measured by the camera 2 is corrected by the simple function. Here, correction is performed by a straight line represented by this function, and this function is stored in the RAM 29 as a correction conversion formula. In FIG. 13, specifically, NO is corrected from 4.2 to 3.0, and NO is corrected from 3.6 to 2.4. Similarly, the values of the other sections are corrected as shown in FIG. 9 based on the correction conversion formula determined by the correlation between the two sections. Thus, third crop information is obtained. Although the obtained third crop information is crop information of nine sections, an average value can be further obtained from the crop information and handled as one crop information in a range photographed by a camera. Although the correction coefficient is represented by a simple function using the representative values of the two sections, the correction coefficient is obtained by the measuring device 30 using the crop information of all the sections photographed by the camera as an explanatory variable. Correlation coefficients obtained from the obtained crop information of all plots as objective variables may be used regardless of whether they are linear or non-linear.

After that, the nitrogen content measured by the camera 2 is corrected by the data processing device 20 based on the correction conversion formula shown in FIG. 12, so that it can be used as a value with further improved measurement accuracy. . This makes it possible to obtain a quicker answer by a simple method of photographing, as compared with a method in which the leaf nitrogen content at a plurality of locations in a field is conventionally obtained only by the measuring device 30. Furthermore, taking into account the fact that researching the nitrogen content of crops by photographing the reference plate and the field is still in the midst of research can greatly contribute to the improvement of measurement accuracy.
The measurement of the nitrogen content by the measuring device 30 is performed in the field 1
It is not necessary to measure the nitrogen content of all the representative crop leaves in the field 1, instead of performing the measurement on all the crop leaves in the field.

It is clear that the crop information obtained from the field 1 in the first and second embodiments for performing the nutrition diagnosis differs depending on the position of the camera 2 with respect to the object. That is, the field 1 here may be a whole field divided by a so-called “ridge”, or may have an area smaller than that of the whole field. When determining the correction value or the correction coefficient, it is important that the information source of the crop information obtained by the camera and the information source of the crop information obtained by the measuring device 30 are in the same field. In addition, the sections in the second embodiment of the nutrition diagnosis are performed by dividing the crop information of the one-side field obtained by one photographing into a plurality of sections.
It is possible to divide the crop information of a smaller area than the one-side field obtained by the above-mentioned photography into a plurality of pieces, and so on. Identity is important.

Next, a third embodiment of the nutritional diagnosis of crops will be described. Here, as a method of obtaining information divided into a plurality of sections from the field 1, the camera 2 obtains the same number of reflected light amounts as the plurality of sections. That is, the difference from the second embodiment of the nutrition diagnosis is that the crop information is individually obtained by the camera 2 from each of the plurality of sections. In this case, the amount of crop information for each section is increased as compared with a case where the crop information of the entire field obtained by one photographing of the second embodiment is divided into a plurality of pieces. The accuracy of the correction coefficient determined by the correlation with the crop information is improved. The determination of the correction coefficient using the crop information of the plurality of sections obtained in this manner is performed by selecting the crop information of two sections from the plurality of sections, preferably the crop information of the section showing the maximum value and the minimum value. Determine the ROM
The storage in the memory 28 and the like are the same as those in the above-described second embodiment, and will not be described. The correction coefficient here may be a correlation coefficient obtained by using the crop information of all the sections taken by the camera as an explanatory variable and the crop information of all the sections obtained by the measuring device 30 as an objective variable, and may be a linear or non-linear correlation. It is the same as in the second embodiment that it can be used without any change.

After that, the nitrogen content measured by the camera 2 is corrected by the data processing device 20 based on the correction conversion formula shown in FIG. . This makes it possible to obtain a quicker answer by a simple method of photographing, as compared with a method in which the leaf nitrogen content at a plurality of locations in a field is conventionally obtained only by the measuring device 30. Furthermore, taking into account the fact that researching the nitrogen content of crops by photographing the reference plate and the field is still in the midst of research can greatly contribute to the improvement of measurement accuracy.
The measurement of the nitrogen content by the measuring device 30 is performed in the field 1
It is not necessary to measure the nitrogen content of all the representative crop leaves in the field 1, instead of performing the measurement on all the crop leaves in the field.

It is clear that the crop information obtained from the field 1 in the third embodiment of the nutrition diagnosis differs depending on the position of the camera 2 with respect to the object. That is, the field 1 here may be a whole field divided by a so-called “ridge”, or may have an area smaller than that of the whole field. In determining the correction coefficient, it is important that the information source of the crop information obtained by the camera and the information source of the crop information obtained by the measuring device 30 are the same section in the same field. In addition, the section in this embodiment captures the crop information of the above-mentioned field as one section by one photographing, and the crop information obtained by one photograph and having an area smaller than that of the above-mentioned field is one section. Catching,
In any case, the identity of the information sources of the crop information to be collected is important in determining the correction value or the correction coefficient.

As described above, the correction for the photographing by the camera 2 can be performed by the area correction, the depression angle correction, and the viewing distance correction. In addition, by using the reference plate 3, an error due to weather such as weather can be corrected, and by using a value of the device 30, an error due to the measurement orientation and the planting density can be corrected. That is, even if the camera is tilted from the ground and the field is photographed diagonally, the correction can be performed in the present invention. When the correction by the device 30 is performed, the value obtained by correcting the weather error due to the reference plate in the measurement by the camera 2 is corrected by the value obtained by directly measuring the crop leaves measured by the same camera 2. Is a value obtained irrespective of the measurement direction and planting density, the value obtained by directly measuring the crop leaves at the value of This value is not affected by many external factors compared to remote sensing.

In collecting crop information by the camera 2 of the above embodiment, not all information obtained by the camera 2 is crop information. In other words, if the data is verified for each pixel of the camera 2, most of the data will be crop information, but in order to obtain the crop information, the crop information will be obtained in a state of looking down naturally, so the soil may be photographed depending on the planting density. There is also. Therefore, in the present invention, pixels that receive crop information and pixels that receive information other than crop information are separated, and only the light reception data of the pixel that receives the crop information is taken in as crop information.

FIG. 14 is a diagram showing changes in the reflectance of soil and crop leaves with respect to wavelength. 750n wavelength
In the range of m to 1300 nm, it has been found that the reflectance of crop leaves causes a difference of about 20% with respect to the reflectance of soil. Therefore, if the reflectance obtained by Expressions 1 and 2 shows a value exceeding, for example, 40%, it is treated as light reception data of a crop leaf, and a value below this value is canceled as not being light reception data of the crop leaf, The received light data exceeding 40% is used as it is, or an average value is obtained for each section and used, and is treated as crop information obtained by the camera 2. For example, it is assumed that light reception data is obtained for a plurality of pixels as shown in FIG. In this case, 1
If it is calculated that the portion represented by the diagonal grid is calculated as a reflectance of 40% or more by the reflected light of the crop leaves and the portion represented by the diagonal lines is calculated as less than 40% in the soil other than the crop leaves, the reflectance is 40 pixels. The light reception data of the pixels which are less than% are canceled out, and those useful as crop information are the light reception data obtained from the shaded pixels in FIG. As described above, in the present invention, the determination of the correction value or the correction coefficient based on the crop information by the camera 2 and the crop information by the measurement device 30 includes:
The selection of light reception data by the camera 2 is added. In this manner, the information selectively obtained by the camera 2 is information obtained only from the crop leaves, and the information obtained from the measuring device 30 is, of course, directly measured from the crop leaves. Nutrition diagnosis of crops can be made accurately using the crop information and the correction value or the correction coefficient.

Although the measurement of the reflected light of the crop leaves by the camera 2 has been described as being obtained by measuring the reflected light of the reference plate, the measurement of the incident light can also be performed in the form of an illuminometer. FIG. 16 shows a simplified illuminometer 93. A filter wheel including a photoelectric conversion unit (silicon sensor) 94 having a spectral characteristic in the near infrared region to the visible light region, and a plurality of narrow band filters 96 for selecting light incident on the photoelectric conversion unit 94 by a stepping motor 97. 95 peripheral parts. The plurality of filters 96 are switched by rotating the filter wheel 95. An opening 98 of a shielding plate is provided on the light receiving surface side (upper part of the drawing) of the photoelectric conversion unit 94, and a diffusion dome 99 formed of a diffusion reflection plate is arranged above the opening 98 with the photoelectric conversion unit 94 as a center. The photoelectric conversion unit 94 and the stepping motor 97 are connected to the control unit 100
The control unit 100 switches the filter 96 by rotating the stepping motor 97, and outputs a signal of the photoelectric conversion unit 94. The type of the filter 96 is the same as the type of the filter 5 of the camera 2. Control unit 1
00 is an I / O port 25 of the data processing device 20 (FIG. 3).
Connected to and controlled. By providing the filter 96 with a filter for shielding light, the zero point correction can be performed by the filter 96.
It becomes possible by switching.

The control unit 100 of the illuminometer 93 uses the signal from the data processing device 20 to switch the filter 96 to the target filter 9.
6, the amount of natural light diffused and reflected from the diffusion dome 99 at this time is detected via the filter 96, and the signal detected by the photoelectric conversion unit 94 is transmitted to the data processing device 20. The data processing device 20 includes an illuminometer 93
By substituting the quantity of light obtained in Equation (5) as the incident light quantity Y instead of the reference plate reflected light quantity P0 into Equation 5, Rij = P ″ ij /
It becomes Y, and the amount of reflected light obtained from the crop leaves can be calculated as the reflectance. When using this illuminometer 93,
The first crop relational expression is obtained based on the reflectance when the illuminometer 93 is the incident light amount.

The whole field can be photographed and corrected in the same manner, and the measurement can be performed at each specific time such as the sprouting stage, which is the time of growing rice, or can be corrected by a method of measuring a part of the field. In this way, it is possible to estimate the nitrogen content of the entire field. This method is more effective if corrections can be made for each variety and each region (for each field). In other words, by storing a plurality of calibration curves for each type, for each region, in the ROM 28, they can be read and used each time. Assuming that the camera 2 in the embodiment has a resolution of about 240,000 pixels and obtains crop information in one shot from the field 10 are 250,
Pixel.

The nitrogen content of the field obtained in this manner is known from the past. For rice, the optimum nitrogen content at any growth stage such as the panicle formation stage and the meiosis stage can be finely classified by cultivar or region. Researched and sought after,
It is possible to compare the nitrogen content based on the corrected first crop information and the third crop information obtained according to the present invention with the reference nitrogen content determined with the growth of the crop determined in the conventional research. The amount of fertilization becomes clearer than the standard, and the amount of fertilization to be applied in the future can be determined according to the amount of nitrogen. The same can be said for the leaf color value, and there is a high correlation between the leaf color value and the leaf nitrogen content, and both show similar changes.
The present invention can be realized even if the method described above is applied to leaf color values. The method described with reference to FIGS. 1 to 3 can be applied not only to the nitrogen content and the leaf color value, but also to the plant height, dry matter, and nitrogen absorption of the crop, and can be applied to crops other than rice.

[0071]

As described above, even in the case of performing nutrition diagnosis by photographing a field from the side of the field, that is, from the ground, a difference in photographing area per unit pixel due to a depression angle and an angle of view generated when the camera is pointed at the field. Can be corrected and the reflected light amount can be further adjusted to a constant area or a predetermined area, so that a nutrition diagnosis with sufficiently high reliability can be performed even when photographing on the ground.

Also, using a camera with a small number of pixels,
Even if there is a difference in the size of the imaging area per pixel, the pixels are divided so that the area is constant, or the pixels are divided so as to have a predetermined area so that the divided area is constant and The data of each pixel can be effectively used.

The nutritional diagnosis of a crop can be easily performed by measuring the reflected light from the leaves of the crop and calculating the nitrogen content of the crop. Is calculated, the nutritional diagnosis of the crop having the high accuracy of performing the nutritional diagnosis of the crop can be performed.

Also, in a simple method of performing a nutritional diagnosis of a crop by measuring the reflected light of the crop leaves and calculating the nitrogen content of the crop, measurement errors due to differences in measurement orientation, leaf fluctuation due to wind, planting density, etc. Can be corrected by the accuracy of performing a nutritional diagnosis of the crop by directly irradiating the crop leaves with light and measuring the reflected or transmitted light to calculate the nitrogen content of the crop. With the method of nutrition diagnosis of crops performed by measuring reflected light, nutrition diagnosis of crops with higher reliability than before has become possible.

[Brief description of the drawings]

FIG. 1 is a layout diagram of a camera and a reference plate installed in a field for measuring reflected light of crop leaves.

FIG. 2 is a schematic block diagram of a camera that measures reflected light from crop leaves.

FIG. 3 is a schematic block diagram of a data processing device.

FIG. 4 is a diagram showing a depression angle, an angle of view, and the like when photographing a field;

FIG. 5 is a diagram showing the pixel coordinates of the image sensor and the size of the imaging area.

FIG. 6 is a diagram showing photographing for determining a correction coefficient for depression angle correction.

FIG. 7 shows the nitrogen content of reflected light obtained from a field divided into a plurality of sections with a fixed area.

FIG. 8 shows the nitrogen content shown by selecting a predetermined area or less from reflected light obtained from a field and dividing the area into a plurality of sections with a predetermined area.

FIG. 9 is a side view in which a part of a main part of the blade nitrogen amount measuring device is broken.

FIG. 10 is a schematic control block diagram of a leaf blade nitrogen amount measuring device.

FIG. 11 is a view showing the operation of a leaf blade nitrogen amount measuring device.

FIG. 12 is a diagram showing a relationship between a blade nitrogen amount measuring apparatus and a nitrogen content rate by photographing.

FIG. 13 is a diagram showing values obtained by correcting nutrition diagnosis in a plurality of sections.

FIG. 14 is a reflectance curve with respect to wavelengths of crop leaves and soil.

FIG. 15 is a diagram showing received light data of crop leaves and soil obtained by a camera.

FIG. 16 is a side sectional view schematically showing an illuminometer for measuring incident light.

[Explanation of symbols]

 Reference Signs List 1 field 2 camera 3 reference plate 4 area sensor 5 narrow band filter 6 filter wheel 7 condenser lens 7 8 control circuit 9 stepping motor 10 operation switch 10 20 data processing device 21 A / D converter 22 frame memory 23 monitor 24 image processing Board 25 I / O port 26 CPU 27 I / F board 28 ROM 29 RAM 30 Leaf nitrogen amount measurement device 31 Main body 32 Light source unit 33 Light intensity detection device 34 LED 35 LED 36 Narrow band filter 37 Narrow band filter 38 Diffuse reflection plate 39 Block 40 Reflected light path 41 Radiation side 42 Diffusing transmission plate 43 Measurement leaf 44 Light quantity detection device 45 Arm 46 Axis 47 Coil spring 48 Micro switch 50 Analog board 51 Light emitting device 52 I / O board 53 CPU board 54 Liquid crystal display LC 55 input unit 56 connection port 57 the power supply board 58 printer 59 I / F board 60 ROM 61 RAM 93 illuminometer 94 photoelectric conversion unit 95 filter wheel 96 narrow-band filter 97 stepping motor 98 openings 99 diffuse dome 100 controller

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[Procedure amendment]

[Submission date] June 23, 2000 (2000.6.2)
3)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of the Invention] Crop diagnosis method

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for obtaining nutrition information of a crop by obtaining crop information such as nitrogen content of a crop from reflected light of a growing crop in a field, and in particular, correcting a reflected light quantity obtained for each of a plurality of pixels. About.

[0002]

2. Description of the Related Art As a first conventional method for obtaining crop information such as nitrogen content, leaf color value, nitrogen absorption amount, plant height or dry matter weight of a crop, a light receiving means such as a digital camera is used. The reference plate on which the crop has been applied and the unit field where the crop grows (or a part thereof) are photographed, and the reflected light amount of the reference plate and the field crop is acquired. From the obtained reflectance and the reflectance, the nitrogen content (nitrogen absorption, leaf color value, plant height, dry matter weight) from the reflectance to determine the nitrogen content of the crop (nitrogen absorption, (Leaf color value, plant height, dry matter weight) was determined, and the growth was diagnosed by comparing with the standard nitrogen amount at that time based on a growth day versus nitrogen amount curve. However, the amount of reflected light of the crop obtained from the field depends on the weather. Also, even if the weather can be corrected by the reference plate, the measurement orientation, wind, and planting density need to be under the same conditions as when a predetermined relational expression was created to obtain the nitrogen content from the reflectance. However, it is necessary to make corrections when these conditions are different, and it is difficult to say that all of them could be corrected just by calculating the reflectance with reference to the reference plate.In practice, the sun altitude, measurement direction, planting density or varieties were limited. The measurement was performed after the measurement.

[0003] As a second conventional method for obtaining crop information, light having a wavelength related to the crop information that increases or decreases based on the growth of the crop, for example, light ranging from a visible light region to a near-infrared region, is irradiated to the crop leaf. An apparatus for measuring the amount of leaf blade nitrogen from the received light amount obtained with respect to light having a wavelength related to crop information and crop information from the received light amount, for example, a nitrogen content relation formula predetermined to calculate the leaf nitrogen content. There is. This device can measure a large amount of leaf nitrogen in a field by measuring many of the leaf blades in the field. However, in order to accurately grasp the crop information of the entire field, detailed measurement over the entire field is indispensable, which is very troublesome.

[0004] In the nutrition diagnosis of crop leaves performed by the first conventional method, remote sensing is called.
When a relatively wide field is targeted, observation is performed from a considerable distance, so that there is no large difference in the area of the subject corresponding to one pixel of the camera. Therefore, the resolution of the camera did not differ from pixel to pixel. On the other hand, even in remote sensing performed very close to the subject, there was no large difference in the area of the subject corresponding to one pixel, and the measurement could be performed to the same extent as described above.

[0005]

In the first method, the measurement is simple but the information of the crop obtained from the field depends on the measurement position and the planting density. Therefore, it is difficult to say that the measurement method is simple but accurate. In addition, when shooting with the camera facing the field, the amount of reflected light obtained for each imaging element of the camera needs to be corrected depending on the angle of depression or angle of view of the camera with respect to the field or the position such as the front side and the side opposite the wide field. It is. The distance between the camera and the field, which is the subject, differs for each pixel, and the imaging area obtained for each pixel differs depending on the distance. Further, the angle of reflection varies depending on the depression angle, which affects the amount of reflected light. The second method has no limitation on the measurement and has higher measurement accuracy and is more advantageous than the first method. However, since the measurement is performed for each leaf of the crop and a large number of measurement points is required,
The difficulty is that it takes a lot of measurement time.

In the conventional remote sensing, the measurement is restricted under the condition that there is no large difference in the area of the subject for each pixel. This was because it facilitated the subsequent correction, but due to its limitations, the observation device became large in order to capture a wide range, and the measurement range became very small when performing very close, Multiple measurements were required.

[0007] From the above, in obtaining crop information by measuring the amount of reflected light of a crop, there is provided a method of correcting the crop so that a large error does not occur even if the camera is taken on the ground. It is an object of the present invention to provide a method for diagnosing a crop in which measurement of information is simple and measurement accuracy is improved.

[0008]

SUMMARY OF THE INVENTION A first crop according to the present invention
As a diagnostic method, a camera having a plurality of pixels is arranged at a predetermined central depression angle with respect to the field, the field is photographed, the reflected light amount of the crop leaves is obtained for each unit pixel, the camera ground height, the pixel depression angle, the pixel The imaging area for each unit pixel is obtained by an area function consisting of conversion variables including the number and the angle of view, the amount of reflected light per unit pixel is corrected for the area by the imaging area, and the maximum area among the imaging areas obtained for each unit pixel is calculated. A plurality of pixels are divided based on the photographing area of the corresponding unit pixel, a reflectance is obtained from the amount of reflected light for each section and the amount of incident light on the crop leaf , and the reflectance and crop information are determined in advance to obtain crop information from the reflectance. The above problem is solved by a crop diagnosing method in which crop information of a certain area is obtained from the determined first crop relation formula and is used as first crop information, and the nutrition of a field crop is diagnosed from the first crop information. Means and It was.

[0009]

In the present invention , when the first crop information is obtained, for example, a camera ground height that naturally occurs based on the photographing angle between a so-called digital camera having a plurality of pixels provided for the field and the field. based on the angle of view by the depression angle and a camera structure in accordance with a shooting range of the pixel taken near, far and shooting range of the pixel taken is different, the amount of received light resulting from the difference in the light receiving area of each pixel position of the camera The present invention provides a method for diagnosing a crop, which can correct the difference between the crops.

[0011] Differences in Taking <br/> shadow area against the light-receiving amount obtained for each unit pixel is corrected as follows. Camera ground clearance,
The angle of depression for each unit pixel accompanying this, the number of pixels that are the structure of the camera, and camera-specific coefficients such as the angle of view based on the size of the imaging element that is an aggregate of pixels and the condensing lens, are used for each unit pixel. A specific (area) function for calculating the area photographed at the time is determined by the secondary projection transformation. Therefore, taking the camera's ground height and depression angle as variables, or adding a camera-specific coefficient to the variables, to obtain the shooting area for each unit pixel,
By dividing the amount of reflected light for each unit pixel by the imaging area for each unit pixel, it is possible to obtain the amount of reflected light for each unit pixel that is not affected by the imaging area. In other words, this makes it possible to realize a correction relating to the distance between the camera and its shooting location (front side and opposite side).

Further, in the present invention, the plurality of pixels are divided based on the photographing area of the unit pixel corresponding to the maximum area among the plurality of pixels. When the camera is directed to a field, the field area obtained with one pixel increases as the distance from the camera increases. Therefore, based on the maximum area of the field obtained by one pixel, other pixels are combined and divided so as to have the same area. That is, even if the number of pixels is different, the pixels are divided so that the field area is constant, and the amount of reflected light is obtained. The reference at this time was based on the maximum area of the field obtained by one pixel. Since the amount of reflected light in a certain area can be obtained,
Even if the field area obtained for each pixel is different, it can be divided into certain areas to obtain the amount of reflected light that is not affected by the resolution of the camera.

On the other hand, the secondCrop diagnosisBy the way, the unit drawing
Of the imaging areas obtained for each element,
And the amount of reflected light from the unit pixelIncident light intensity on crop leavesAnd from anti
The emissivity was calculated. When you point your camera at the field,
The field area obtained with one pixel increases as the distance from the camera increases
growing. Therefore, it is suitable for nutrition diagnosis of crop leaves.
Pixel of the field area that exceeds the predetermined area
No information is adopted, and the image of the field
Use only raw information. And the field obtained with one pixel
Other pixels are set to the same area based on the predetermined area of the field area.
We decided to combine and classify them. That is,
Pixels so that the field area is constant even if the prime numbers are different
To obtain the amount of reflected light. Standard at this time
Was based on a predetermined field area. Reflected light in a given area
Camera on the ground, pixel by pixel
Even if the obtained field area is different, divide it into the specified area
To obtain the amount of reflected light that is not affected by the resolution of the camera.
Can be. Here, the predetermined area is used for nutritional diagnosis of crop leaves.
Suitable field area, eg 1m² 5m from² To
It is only about.

The ratio of the amount of reflected light of a given area or predetermined area obtained in this way to the amount of reflected light of the reference plate or the amount of incident light on the crop leaves by the sun irradiation light is determined as the reflectance in the given area or given area. .

The reflectivity of a fixed area or a predetermined area obtained as described above is a reflectivity obtained by photographing a field from a ground with a camera, and the influence of the camera height, depression angle, or camera structure on the field. Based on the corrected reflectance and the reflectance of the crop leaf whose crop information is known, a first crop relational expression predetermined for obtaining the crop information from the reflectance is determined by multiple regression analysis. The first crop information of the crop leaves can be obtained from the first crop relational expression and the reflectance obtained by the above-described correction and calculation. Note that the number of wavelengths of the reflected light amount is not limited to one, and the reflected light amount at a wavelength necessary for obtaining crop information is measured. Therefore, an operation for determining the reflectance for each of a plurality of wavelengths is required. In obtaining each function or coefficient, the reflected light amounts at a plurality of wavelengths can be combined.

As a third crop diagnosis method according to the present invention, a camera having a plurality of pixels is arranged at a predetermined central depression angle with respect to a field, the field is photographed, and the amount of reflected light of the crop leaves is obtained for each unit pixel. Calculate the shooting area for each unit pixel by an area function consisting of conversion variables including the camera viewing distance, the pixel depression angle, the number of pixels, and the angle of view, and correct the area of the reflected light amount per unit pixel by the shooting area. A plurality of pixels are divided based on the area of the unit pixel corresponding to the maximum area in the obtained photographing area, and the reflected light amount and the crop leaf for each section are divided.
The first crop information is obtained by calculating the reflectance from the amount of light incident on the first crop information, and determining the crop information of a certain area from the reflectance and a first crop relation formula predetermined for obtaining the crop information from the reflectance. The means for solving the above-mentioned problem is provided by a crop diagnosis method for diagnosing nutrition of a field crop based on the first crop information.

In the third method, the visual field distance is used instead of the depression angle used for the specific function in the first method. In other words, the difference in the photographing area with respect to the amount of received light obtained for each pixel is determined by the height of the ground of the camera, the visual field distance (distance between the pixel and the photographing point) for each pixel, and the number of pixels, which is the structure of the camera. A specific (area) function for obtaining an area photographed for each pixel is calculated by a secondary projective transformation based on a camera-specific coefficient such as an angle of view based on the size of a photographic element which is an aggregate of pixels and a condenser lens. Is determined. Therefore, by taking the camera's ground height and viewing distance as variables, or adding a camera-specific coefficient to the variables, the shooting area for each pixel is obtained, and the amount of reflected light for each pixel is divided by the shooting area for each pixel. The amount of reflected light for each pixel, which is not affected by the above, can be obtained. In other words, this makes it possible to realize a correction relating to the distance between the camera and the shooting location (front side and opposite side). Since the other pixels are divided so as to have a constant area based on the maximum area among the photographing areas of the unit pixels as in the first embodiment, the description will be omitted.

As a fourth crop diagnosis method according to the present invention, a camera having a plurality of pixels is arranged at a predetermined central depression angle with respect to a field, and the field is photographed to obtain the amount of reflected light of crop leaves for each unit pixel. The imaging area of each unit pixel is obtained by an area function composed of conversion variables including the viewing distance of the camera, the pixel depression angle, the number of pixels, and the angle of view, and the amount of reflected light per unit pixel is corrected for the area by the imaging area. Among the obtained photographing areas, the reflectance is obtained from the reflected light amount of the unit pixel which is equal to or smaller than the predetermined photographing area and the incident light amount on the crop leaf , and the reflectance is determined in advance to obtain the crop information from the reflectance. In order to solve the above-mentioned problem, a crop diagnosing method for diagnosing the nutrition of a field crop based on the first crop relation formula and obtaining crop information of a certain area based on the first crop relation formula and using the first crop information as a first crop information. Means It was.

In the fourth method, the visual field distance is used instead of the depression angle used for the specific function in the second method. In other words, the difference in the photographing area with respect to the amount of received light obtained for each pixel is determined by the height of the ground of the camera, the visual field distance (distance between the pixel and the photographing point) for each pixel, and the number of pixels, which is the structure of the camera. A specific (area) function for obtaining an area photographed for each pixel is calculated by a secondary projective transformation based on a camera-specific coefficient such as an angle of view based on the size of a photographic element which is an aggregate of pixels and a condenser lens. Is determined. Therefore, by taking the camera's ground height and viewing distance as variables, or adding a camera-specific coefficient to the variables, the shooting area for each pixel is obtained, and the amount of reflected light for each pixel is divided by the shooting area for each pixel. The amount of reflected light for each pixel, which is not affected by the above, can be obtained. In other words, this makes it possible to realize a correction relating to the distance between the camera and the shooting location (front side and opposite side). Since it is the same as the above-described second method to adopt the pixels having the acquired field area equal to or smaller than the predetermined area and to divide the adopted pixels so as to have the predetermined area, the description thereof is omitted.

By the way, as a method for obtaining the second crop information, light having a wavelength related to the crop information which increases or decreases based on the growth of the crop, for example, light ranging from the visible light range to the near-infrared range is directly applied to the crop leaf blade. Irradiation, to calculate the leaf nitrogen amount from at least one of the reflected light amount or transmitted light amount obtained with respect to the light of the wavelength related to the crop information, and the crop information such as the leaf blade nitrogen amount is known crop leaf light amount The leaf nitrogen amount can be measured from a predetermined nitrogen amount relational expression. This device can measure a large amount of leaf nitrogen in a field by measuring many of the leaf blades in the field. Therefore,
It is effective to further correct the above-mentioned first crop information.

Correction is made by effectively combining the two useful techniques for obtaining the first crop information and the second crop information.
The method is described below. The difference between the first crop information and the second crop information obtained from each is obtained, and the first crop information is corrected by the difference, so that only the error due to weather change (weather, time, sun position) is obtained. Not the cultivation change (measurement orientation, planting density)
Can be corrected. In particular, it is optimal to perform a nutrition diagnosis at a plurality of locations in the same field because the correction can be easily determined.

By storing the difference between the first crop information and the second crop information determined as described above,
If only the first crop information is obtained from the unknown crop of a certain area in the field where the first crop information is obtained, the first crop information can be corrected based on the first crop information and the difference, and planting can be performed. Not only can errors due to the density and the measurement direction be easily corrected, but also by having correction values, it can be realized as an apparatus, and the apparatus can be used as an easy crop diagnosis method.

The first crop diagnosis method and the second crop diagnosis
The following method is applied to perform a more strict correction from the cutting method . That is, the first crop information is obtained, the obtained first crop information is divided into a plurality of sections, at least two points of data are selected from the plurality of sections, and a crop of the two points of data is selected. By obtaining the second crop information directly from the crop leaves in the same field, the correlation between the two points of the first and second crop information is clarified and a correction conversion formula is determined. Is used to correct all values of
Calculation formula can be obtained a plurality of crop information from a range Upon Request can be corrected over the first crop information in a wide range depending further correction conversion formula.

The first crop diagnosis method and the second crop diagnosis
As another method for performing correction by the cutting method, in a field exposed to natural light, from a crop in each of a plurality of plots, the reflectance of light having a wavelength related to crop information that increases or decreases due to the growth of the crop is measured. From the reflectance and the first crop-related equation predetermined to determine the crop information from the reflectance, the crop information for each section is obtained and stored as the first crop information, and the first crop information for each of the stored sections is stored. At least two sections of crop information are selected from the crop information, and light is irradiated to the leaf blades of the crop corresponding to the two sections of the field, and at least one of transmission and reflection of a wavelength related to the crop information that increases or decreases according to the growth of the crop. The light quantity is measured, and a second crop-related equation predetermined for obtaining crop information from the light quantity is used to calculate
Obtain the crop information of the section and store it as the second crop information,
A correction conversion formula for correcting the first crop information based on the second crop information is determined, and the first crop information is corrected for each section using the correction conversion formula to obtain third crop information. The nutrition of the field crop may be diagnosed by the third crop information.

Unlike the above-mentioned correction method, this correction method obtains information of a plurality of sections individually. By selecting data of at least two sections from the plurality of sections and obtaining the second crop information directly from the crop leaves of the same section as the crop of the two-section data, the two pieces of first and second crop information are obtained. The correction conversion formula is determined by clarifying the correlation with the point data, and all the values of the plurality of sections are corrected based on the correction conversion formula.
In obtaining the conversion formula, a plurality of crop information can be obtained from a wide range, and the first crop information can be corrected over a wide range by the correction conversion formula.

According to the method for diagnosing crops of the present invention , the first crop-related formula and the correction conversion formula determined as described above are stored, and the reflectance is measured from the crop leaf of an unknown field. Since the third crop information can be obtained by the first crop relation formula and the correction conversion formula, the above-described items can be realized as a device by storing the above-mentioned items in the storage unit of the control device and appropriately reading and calculating the same. It is possible to provide a device which not only enables crop diagnosis by the device but also improves measurement accuracy.

Further, an arbitrary 2 item selected from a plurality of sections can be selected.
By setting the section to be a section indicating the maximum value and the minimum value of the first crop information, the straight line for the correction conversion of the first crop information and the second crop information is ranked higher regardless of the remaining data. It can be easily determined by the lower two points.

Although various types of crop information can be supposed, it is optimal to use the leaf nitrogen content or leaf color value for performing a nutritional diagnosis of the crop. It can be understood from the fact that the suitability immediately appears.

In the method for diagnosing crops according to the present invention, in order to measure the reflectance of light having a wavelength related to the crop information which increases or decreases as the crop grows, the reflected light of the crop is imaged by an image sensor comprising a plurality of pixels. Then, a pixel that has received the reflected light corresponding to the crop is selected, and the reflectance is measured based on the received light data of the selected pixel to obtain the first crop information. Depending on the planting density and the size of the imaged target field, that is, whether it is within the unit field or about 1 square meter, the reflected light obtained from the imaging means by a digital camera etc. It is not necessarily the reflected light obtained from. That is, when viewed in pixel units, reflected light from other than crops, for example, reflected light from field soil may be included. Therefore, it is preferable to select only the pixels having the reflectance in the predetermined range and use the selected pixels as the reflected light obtained from the crop to obtain the first crop information based on the received light data.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A measuring apparatus according to the present invention will be described with reference to FIGS. Here, a rice crop will be described as an example. FIG. 1 shows an example in which a crop in the field 1 is imaged. Here, a camera 2 serving as a light receiving device for measuring the reflected light of the crop is installed toward the field 1 where the crop grows. The field 1 is naturally exposed to natural light. Further, a white reference plate 3 is installed in the field.

FIG. 2 is a simplified block diagram of the camera 2. The camera 2 has, for example, 240,000 pixels (600 × 4 pixels).
An area sensor 4 having a resolution of about 00) is provided. The camera 2 has a filter wheel 6 having a plurality of narrow-band filters 5. For example, the filter 5 is switched by rotating the filter wheel 6. Filter 5
Is received by the area sensor 4 via, for example, a condenser lens 7 as optical means. The filter wheel 6 is rotated by a stepping motor 9 driven and controlled by a control circuit 8. Further, the control circuit 8
Sends the light receiving signal of the sensor-4 to the data processing device 20.

Here, the filter 5 is, for example, 450, 550, 625, 650, 675, 700n having a wavelength in the visible light range.
m is appropriately selected. Also, the near infrared wavelength of 75
0, 850, 950 to 1300 nm. For these wavelengths, it is necessary to select a band that shows a characteristic change with a change in the nitrogen content or leaf color value of the crop leaves. Accordingly, the filter may use both the visible light region and the near infrared region, or may use only one of them. Note that the wavelength is not limited to the present embodiment. Although four filters are shown in FIG. 2, the filters are mounted according to the purpose and can be changed at any time, and the number of filters to be used is not limited. An operation switch 10 is further connected to the control circuit 8, and the operation switch 10 is a photographing start switch 10 for photographing.
a, a shooting stop switch 10b for stopping shooting, a filter changeover switch 10c for switching a filter,
It is provided with a data transmission switch 10d for transmitting photographing data, a power switch 10e, and the like.

FIG. 3 shows a block diagram of the data processing device 20. A data processing device 20 shown in FIG. 3 is an analog-to-digital converter (hereinafter, referred to as an “A / D converter”) 21 that converts an image signal of the area sensor 4 into a digital signal.
And a frame memory 22 for storing the image data after A / D conversion, a monitor 23 for visually displaying the image data, and an image processing board 24. ) To a CPU 26 for performing arithmetic processing on image data. Further, a leaf blade nitrogen amount measuring device 30 described later is connected via an interface board (hereinafter, referred to as an “I / F board”) 27. Read-only memory (hereinafter, referred to as “ROM”) 28 further storing a control program and the like.
And a read / write memory (hereinafter, referred to as “RAM”) 29 that can store the operation result and the like and read it out as appropriate,
26.

When the power switch 10e of the camera 2 is pressed, the reflection signal of the image is received by the area sensor 4 to become an image signal, and this image signal is sent to the data processing device 20 by pressing the data transmission switch 10d. You. In the data processing device 20, the image data is processed by the image processing board 24 and displayed on the monitor 23. Monitor 2
In step 3, the position of the camera 2 is set while confirming the field 1, and the photographing range is determined. When the photographing range is determined, the photographing start switch 10 is passed through the currently set filter 5.
After pressing a, the leaves of rice growing in the field 1 are photographed, and then a signal for rotating the stepping motor 9 is output from the control circuit 8 by the filter changeover switch 10c, and the filter 5 is switched by rotating the filter wheel 6;
The photographing switch 10a is pressed to photograph. In this way, the photographing is performed for each required filter 5 while sequentially switching the filters 5. As a result, an image signal is created for each filter 5. Here, if the area sensor 4 of the camera 2 does not have a large-capacity storage element, the data transmission switch 10 transmits data to the data processing device 20 every time shooting is performed.
Press d.

The data of the unit pixel photographed by the camera 2 of the measuring device configured as described above is processed as follows. FIG. 4 is a diagram showing the ground height h, the depression angle θ, the angle of view ψ, the viewing distances l1, l2, and the like of the camera 2 when the field is photographed from the viewpoint 0 of the camera 2. FIG. 5A shows the pixel coordinates ij of the area sensor 4, and FIG. 5B shows the field area Aij acquired by the pixels. FIG.
As is apparent from the above, the field images acquired at the respective pixel coordinates ij have different areas. Therefore, even in the same field, the density of the information amount differs for each pixel coordinate ij. This is corrected by the following area function. The area function referred to here is a mathematical analysis method generally called a quadratic projection transformation, and therefore only its outline will be described. The following area function is established by the ground height h or the viewing distance l of the camera 2, the angle of depression θ of photographing, the angle of view で which is a coefficient unique to the camera 2, and the number of pixels.

(Depression angle) Aij = f (θ, h, i, j, x1, x2...) (Viewing distance) Aij = g (θ, 1, i, j, x1, x2...) Aij: pixel Field actual area acquired at coordinates ij, i, j: pixel coordinates x1: angle of view (camera specific) x2: number of pixels (camera specific) Thus, depression angle θ, ground height h or viewing distance l
, The actual area Aij for each pixel coordinate can be calculated. That is, the actual area can be obtained by either the field actual area formula 1 obtained based on the depression angle or the field actual area formula 1 obtained based on the viewing distance.

Here, assuming that the amount of received light (intensity) of the reflected light at the pixel coordinates ij is Pij

[Mathematical formula-see original document] P'ij = Pij / Aij, and the received light amount P acquired by the pixel ij with the actual area Aij
By dividing ij, it is possible to obtain the amount of reflected light per unit area that is not affected by the magnitude of the actual area of the field acquired at the pixel coordinates ij. As described above, the area correction can be performed for each pixel coordinate ij, and the amount of reflected light for each pixel coordinate ij that is not affected by the size of the actual area obtained by imaging is obtained. As described above, the area correction by the secondary projection conversion in the case where the image is taken at the predetermined ground height h or the viewing distance l and at the predetermined depression angle θ has been described.

Next, since the depression angle θ differs for each pixel coordinate ij, the depression angle correction accompanying θ is performed. As shown in FIG. 6, the reflected light of the reference plate or the crop leaf at the same position in the field is measured at the same distance. For example, the correction coefficient may be determined by changing the depression angle θ1 from the depression angle θ2, preferably based on the amount of reflected light at the pixel coordinates at the center of the area sensor 4. For example, when the depression angle θ is 60 °, the correction coefficient of the reflected light amount is K60 ° = 1.
If so,

Depression angle θ = 60 °: K60 ° = 1 Depression angle θ = 50 °: Reflection light amount at depression angle 50 ° / reflection light amount at depression angle 60 ° = Correction coefficient at depression angle 50 ° = K50 ° Depression angle θ = 40 °: Depression angle Reflection light amount at 40 ° / reflection light amount at 60 ° depression angle = Correction coefficient at 40 ° depression angle = K40 ゜ Depression angle θ = 10 °: Reflection light amount at 10 ° depression angle / reflection light amount at 60 ° depression angle = Correction coefficient at 10 ° depression angle = K10 ゜, the correction coefficient at each depression angle θ is determined, and the correction coefficient Kij for each pixel coordinate ij is determined. Therefore, by the P′ij obtained after the area correction and the correction coefficient Kij,

P′ij = Kij · P′ij, and the depression angle can be corrected by the depression angle θ.
The correction regarding the above has been described. In any case, in the area correction, a predetermined value (θ, h, l, etc.) is input in advance, or in the depression angle correction, the amount of reflected light is measured in advance at a plurality of depression angles θ, and a correction coefficient is set for each pixel coordinate. Kij
It is necessary to define

Next, the reflected light amount received by the area sensor 4 of the camera 2 is the reflected light amount of the reference plate 3 and the reflected light amount of the crop leaves in the field 1. When measuring the amount of reflected light from the reference plate 3, it is preferable to measure the amount of reflected light from the reference plate at a depression angle θ used as a reference in the depression angle correction, in the above example, at a depression angle of 60 °. Assuming that the reference plate reflected light amount is the incident light amount to the crop leaves and the measured reference plate reflected light amount is P0,

Rij = P "ij / P0 Rij: The reflectance of rice leaves can be determined by the reflectance at each pixel coordinate ij. This reflectance is used to determine the nitrogen content of rice leaves. These formulas 1 to 5 are stored in the ROM 28. The above-mentioned reference plate reflected light amount P0 is measured and stored as follows: The filter 5 provided in the camera 2 is switched and the reference is set for each filter. The amount of reflected light from the plate 3 is measured and sent to the data processing device 20, which converts the reflected light into digital data by the A / D converter 21 and stores the data in the RAM 2.
9 is stored. That is, the value of the reference plate reflected light amount P0 is measured and stored for each filter 5.

The filter 5 is switched by the camera 2 and the amount of reflected light of the leaves of the rice in a certain area of the field 1 is received and transmitted to the data processor 20 for each filter. The signal is converted into a digital signal by 21 and stored in the frame memory 22. CPU26
Calculates the average value of the amount of light received by each pixel with respect to the amount of reflected light of the leaves of each filter 5 stored in the frame memory 22 and calculates the reflectance based on the above-described mathematical expression stored in the ROM 28 in advance. And store it in the RAM 29. This stores the reflectance of a certain range of the unit pixels, for example, the crop leaves in a range of one square meter.

FIGS. 7 and 8 show an example in which data of 240,000 pixels obtained by photographing crop leaves in the field 1 is further divided into a plurality of sections and processed. For example, the filter 5 is switched by the camera 2, and for each filter, the reflected light amount of the rice leaf in a certain area of the field 1 is received and transmitted to the data processing device 20. The signal is converted into a digital signal and stored in the frame memory 22. The CPU 26 determines the amount of reflected light of the leaves for each filter 5 stored in the frame memory 22.
As shown in FIG. 7, for example, sections NO to are determined from the upper left, an average value of the amount of light received by each pixel in the section is obtained, and each section is The reflectance is calculated and stored in the RAM 29. The image processed by the image processing board 24 is displayed on the monitor 23.

The division here is determined as follows. First, a first method of the division shown in FIG. 7 is based on the actual field area of the pixel (each in FIG. 7) showing the maximum value among the actual field areas Aij obtained by unit pixels by photographing the field. That is, with the maximum actual field area as a reference area, a plurality of adjacent pixels are combined to divide all the pixels so as to have a constant area. At this time, even if the unit pixel is further divided, the reflected light amount per unit area can be reflected on the divided area because the reflected light amount per unit area is obtained, so it is possible. It is assumed that the image data is divided as described above and divided into nine data for convenience. That is, it is assumed that each of the pixels at the top of FIG. 7 has the maximum real area, and the following pixels are divided into a certain area based on this real area. This shows that the area is constant. Actually, it is a more complicated division, but it is simply shown here. Here, it is preferable that the camera is arranged so that the fixed area is 1 m ² to 5 m ² and shooting is performed. Even if the unit is divided into smaller units, not only the information on the crop leaves is not reflected in all the reflected light amounts obtained for each pixel, but also the work efficiency is reduced due to the size of the crop leaves and the planting density. Conversely, if the sectional area is too large, the work efficiency will be improved, but the obtained information will be coarse and the accuracy will be reduced.

[0042] Next a second method of classification shown in FIG. 8, of the field actual area Aij obtained in a unit pixel by photographing a field, predetermined area, included in the pixel (segment-for example, it does not exceed 1 m ² Is selected, and a plurality of adjacent pixels are combined using a predetermined area as a reference area to divide all the pixels into a predetermined area. Even if it such that a unit pixel that time further divided, since the reflected light amount per unit area are determined, the reflected light amount per unit area divided area is possible because it reflects. Here, it is assumed that the image is divided into nine sections for convenience. In FIG. 8, the uppermost three pixels are pixels that exceed a predetermined area and are excluded, and among the pixels having a certain area or less, the division is just a predetermined area, and is a predetermined area for three pixels. Indicates that a predetermined area is obtained for four pixels. Actually, it is a more complicated division, but it is simply shown here. When the predetermined area is 1 m ² , even if the area is divided into smaller units, not only the information on the crop leaf is not reflected in all the reflected light amounts obtained for each pixel due to the size and the planting density of the crop leaf, but also , Work efficiency is reduced. Conversely, if the sectional area is too large, the work efficiency will be improved, but the obtained information will be coarse and the accuracy will be reduced.

The RAM 29 has a plurality of filters 5.
The reflectance of the crop leaves within the light receiving range for each of the filters and the reflectance of each crop leaf processed into nine sections for each filter 5 are stored. The filter 5 stored in the RAM 29
By using the reflectance of each of the filters or the reflectance processed in 9 sections for each filter 5 as an explanatory variable, a leaf growing in the same light receiving range or in the same section is collected, and the crop information of the leaf, for example, The relationship between the direct chemical analysis of the nitrogen content or the leaf color value obtained by directly measuring the leaf color, and using the nitrogen content or the leaf color value as an objective variable to obtain the crop information of the crop leaf within the light receiving range. An equation and a relational equation (first crop relational equation) for obtaining the crop information of the crop leaves for each of the nine sections are created and stored in the ROM 28.

More specifically, if there is a reflectance R1 by the filter 1, a reflectance R2 by the filter 2, a reflectance R3 by the filter 3, and a reflectance R4 by the filter 4 in the section NO, the crop leaves in the section are chemically analyzed. When the nitrogen content N1 obtained by

Assuming that N1 = F0 + F1 · R1 + F2 · R2 + F3 · R3 + F4 · R4, a plurality of nitrogen contents N are measured.

N1 = F0 + F1 · R11 + F2 · R21 + F3 · R31 + F4 · R41 N2 = F0 + F1 · R12 + F2 · R22 + F3 · R32 + F4 · R42 · · · · · · Nn = F0 + F1 · R1n + F3 · R4n By regression analysis,

N = F0 + F1 · R1 + F2 · R2 + F3 · R3 + F4 · R4 + C N: Nitrogen content to be measured, F0 to F4: constant, R1 to R
4: Relational reflectance (first crop relational expression) can be obtained as the reflectance C for each filter. The relational expression can be similarly obtained for the leaf color value. This equation 8 is stored in the ROM 28.

If Equations 1 to 5 and Equation 8 are stored in the ROM 28 in this manner, the reference plate and the rice leaves in the light receiving area are photographed by the camera 2 and this image signal is processed by the data processor 20. To the data processing device 20
Then, the nitrogen content can be calculated based on the first crop relational expression. As a result, the nitrogen content of the rice within the light receiving range or the nitrogen content (first crop information) NO〜 of each section can be obtained. The numerical values described in each section in FIG. 7 are examples of the nitrogen content obtained at this time.

Next, an embodiment of the apparatus 30 for measuring the amount of nitrogen in the blade blade will be described with reference to FIGS. FIG. 1 is a side view in which a main part of a portable nitrogen amount measuring device (hereinafter referred to as “measuring device”) 30 is broken. FIGS. 9 and 10 show a configuration in which a light source unit 32 is provided in an upper body 31 and a photodiode (not shown) serving as a light amount detection device 33 is provided below. The light source unit 32 includes a plurality of light emitting elements LED3 having different wavelength peaks on the same circumference.
The LEDs 34 and 35 are provided with narrow band filters 36 and 37 having different wavelength bands. The wavelength band is preferably 500 nm to 1100 nm, and from this wavelength band, a narrow band filter 36 of any specific wavelength related to the required leaf nitrogen amount or leaf color value,
37 is selected. The light emitted from each of the LEDs 34 and 35 is converted into light of a specific wavelength by the narrow band filters 36 and 37, and is incident on the diffuse reflection plate 38 that reflects the light. A block 39 is formed so that the light beams of the LEDs 34 and 35 are incident on the diffuse reflection plate 38 at a substantially constant angle.

The light reflected by the diffuse reflection plate 38 enters a reflection light path 40 provided at the center of the block 39, and enters a diffusion transmission plate 42 provided on the radiation side 41 of the reflection light path 40. Diffuse reflector 42 is provided perpendicular to the optical axis of the reflected light path 40, it is formed of a glassy or opalescent glass circular frosted. Reflected light path 40 and diffuse reflector 38
The light leaves the reflected light path 40 while repeating reflection and diffusion in the space surrounded by
The light enters the light amount detection device 44 via the light source 3.

Further, an upper lid 31 is provided on the outer periphery of the upper part of the light amount detection device 32, and an arm 45 extending from the upper lid 31 is supported by a shaft 46. Further, a coil spring 47 is loosely fitted on a shaft 46 on which the upper lid 31 is supported, and acts so as to always push up the upper lid 31. That is, as shown in FIG. 11, in the measurement, the measurement is enabled by inserting the measurement leaf 43 into the measurement place and pressing down the upper part of the upper lid 31. At the timing of this measurement, it is detected that the push-down protrusion (not shown) provided below the upper cover 31 by pushing down the upper cover 31 pushes down the microswitch 48 provided at the opposing position, thereby pressing down the upper cover 31. (Light irradiation and light quantity measurement).

Next, a block diagram of the absorbance measuring device 1 will be described with reference to FIG. The transmitted light amount of the sample leaf 43 detected by the measuring unit including the light source unit 32 and the light amount detecting device 33 is converted into an analog signal by the light amount detecting device 44 and communicated to the analog board 50. The light source unit 32 is provided with a light emitting device 51 of LEDs 34 and 35. The analog board 50 performs A / D conversion from analog to digital signals or V / F conversion from voltage to frequency. The converted signal is input to a CPU board 53 serving as an arithmetic and control unit via an I / O board. The I / O board 52 includes a liquid crystal display LCD 54 for displaying a measurement result, a calculation result or an operation instruction, an input unit 55 for performing an operation, and an RS for inputting and outputting data to an external device.
A 232C connection port 56 and a switch 48 are provided. The CPU board 53 and the I / O board 52 are connected so that power is supplied from a power supply board 57. The printer 58 is connected to the CPU board 53 via a printer I / F board 59. Further, the CPU board 53 includes a read only memory (hereinafter referred to as “ROM”) 60 and a read / write memory (hereinafter referred to as “RAM”).
61) are connected. The ROM 60 stores a plurality of calibration curves for each field or each variety. This calibration curve calculates absorbance from a plurality of received light amounts obtained by irradiating light to a plurality of leaves whose nitrogen content has been measured in advance, and uses this absorbance as an explanatory variable, and a plurality of known nitrogen contents as objective variables. Is a relational expression (second crop relational expression) for performing a multiple regression analysis to obtain a predetermined nitrogen content rate (second crop information). The description of the multiple regression analysis will be omitted because the procedure for obtaining the above-described formulas is the same as that of the above-described procedure. Furthermore, this R
The OM 60 stores a series of programs for executing the calculation and display from the measurement of the absorbance for measuring the absorbance and calculating the quality such as the nitrogen content in the measuring device 30.

The operation of the measuring device 30 configured as described above will be described below. Sample leaf 4 in measuring device 30
3 is inserted and the upper lid 31 is pushed down, the signal of the switch 48 is communicated to the CPU board 53, and the CPU board 53
, A signal is output to the light emission control device 51, and a light emission signal is sent from the light emission control device 51 to the light source unit 32. Accordingly, light is alternately emitted from the LEDs 34 and 35 toward the sample leaves 43. The light emitted from the LEDs 34 and 35 is converted into light having a specific wavelength in the near-infrared region and visible light region by the narrow band filters 36 and 37. Since the sample leaves 43 are reached, the sample leaves 43 are evenly irradiated to the same extent as the integrating sphere.

When the sample leaves 43 are irradiated with light, the transmitted light or the reflected light is converted by the light amount detection device 44 into the LED 3.
Light is received every 4, 35, and the received light signal is transmitted to the analog board 50 for A / D conversion. The analog board 50 performs A / D conversion, and then inputs the data to the CPU board 53 via the I / O board 52. The CPU board 53 calculates the light transmittance or the absorbance from the transmitted light or the reflected light of the sample leaf 43, and the value is stored in the RAM 61. The measured nitrogen content of the leaf can be calculated from the absorbance stored in the RAM 61 and the relational expression for calculating the nitrogen content stored in the ROM 33 in advance. The input unit 55 includes a power switch 55a for turning on the power of the measuring device 30, a measurement switch 55b for enabling transmitted light measurement, a calibration curve (formula) stored in the ROM 60, and absorbance or transmitted light data stored in the RAM 61. A readout switch 55c having a switching function of reading out a calculation result, a sample number, and the like is provided.

Hereinafter, a first embodiment in which a nutrition diagnosis of a field crop is performed based on the first crop information and the second crop information will be described. The camera 2 measures the reflected light from the reference plate 3 and the amount of reflected light of a wavelength related to, for example, the nitrogen content, which is crop information that increases or decreases as the rice grows from the field 1 exposed to natural light. As shown in FIGS. 2 to 4, in the data processing device 20, the reflectance is calculated by the reflected light amount of the leaves within the light receiving range measured by the camera 2 and the formula for calculating the reflectance within the light receiving range stored in the ROM 28. Based on the calculated and calculated reflectance and the first crop relational expression stored in the ROM 28, the nitrogen content in the light receiving range of the camera 2 as the first crop information is obtained and stored in the RAM 29.

Next, the case where the nitrogen content of the rice leaves growing within the light receiving range of the camera 2 is measured and corrected will be described. The nitrogen content (second crop information) of the rice leaves measured by the device 30 is a measurement value obtained directly from the leaves of the rice, and is not affected by the measurement orientation, the planting density, and the like. Therefore, in the present invention, the difference between the first crop information and the second crop information is calculated. For example, if the first crop information is 4.0% in the previous measurement and the second crop information is 3.0% in the measurement of the device 30, the value of the device 30 is stored in the RAM 61 as the second crop information. I do. The second crop information obtained by the measuring device 30 is transmitted from the connection port 56 of the measuring device 30 via the I / F board of the data processing device 20 to the data processing device 20 and RA is output.
Store it in M29. The device 20 determines the first crop information based on the difference between the first crop information and the second crop information in the RAM 29, -1%.
-1% is added to the crop information of the above, and corrected to 3.0%.

In other words, this difference is stored again in the RAM 29 as a correction value, and the reflected light of the crop leaves in other light receiving ranges is measured by the camera 2 and the value calculated by the device 20 is as follows:
All are corrected by adding the difference -1%. Thereby, the measurement which is not affected by the measurement direction and the planting density can be realized by the camera 2 and the device 20. And RAM
After storing the correction value in 29, at least many measurements by the device 30 in the same field become unnecessary,
With one measurement by the camera 2, measurement can be performed with unprecedented accuracy. Note that the measurement of the nitrogen content by the measuring device 30 does not need to be performed for all the crop leaves in the field 1, but may be performed by measuring the nitrogen content of the representative crop leaves in the field 1.

Next, a second embodiment of the nutrition diagnosis will be described. The camera 2 measures the reflected light from the reference plate 3 and the amount of reflected light of a wavelength related to, for example, the nitrogen content, which is crop information that increases or decreases as the rice grows from the field 1 exposed to natural light. As shown in FIGS. 2 to 4, NO to NO measured by the camera 2 in the data processing device 20.
The reflectance is calculated by the reflected light amount divided into the sections and the formula for calculating the reflectance for each section stored in the ROM 28, and the calculated reflectance and the first crop relational expression stored in the ROM 28 are used to calculate the reflectance. The nitrogen content for each section, which is one crop information, is obtained and stored in the RAM 29.

Next, the nitrogen content of any two sections is selected from the values for each section obtained here by the operator or by the apparatus 20, and preferably, the nitrogen content becomes the maximum value and the minimum value. Select the parcel that has been set. 7 or 8, for example, a plot of rice leaves growing in a field plot corresponding to a plot of 4.2% of the maximum value of NO and a plot of 3.6 % of the minimum value of NO. The nitrogen content is measured by the measuring device 30. The nitrogen content measured here is not affected by the measurement orientation, planting density, and the like.

As described above, the measuring device 30 directly emits light having a wavelength related to the leaf nitrogen rate, which is crop information that increases or decreases as the crop grows, from the leaf blade of the rice corresponding to the two selected sections of the field. In this example, the amount of light received is converted into the absorbance from the amount of light obtained by irradiation, and the two divisions are calculated from the absorbance and a second crop-related equation predetermined to determine the leaf nitrogen rate from the absorbance. Is calculated. Then, the NO section is determined to be 3.0% and the NO7 section is determined to be 2.4%, and this value is stored in the RAM 61 as second crop information. The nitrogen content of the two compartments determined by the measuring device 30 is sent out to the data processing device 20 from the connection port 56 of the measuring device 30 via the I / F board of the data processing device 20 and R
Store it in AM29.

The first crop information (NO to NO nitrogen content) also stored in the RAM 29 is corrected for each section based on the nitrogen content of the two sections as the second crop information stored in the RAM 29. Using the third crop information will be described with reference to FIG. In FIG. 12, the horizontal axis represents the nitrogen content (second crop information) measured by the measurement device 30, and the vertical axis represents the nitrogen content (first crop information) calculated by the data processing device 20. FIG. That is, the nitrogen content of the two sections by the measuring device 30 is 3.0% and 2.4%.
And 4.2% of NO in two sections by the data processing device 20
FIG. 4 is a diagram created by using the NO and the nitrogen content of 3.6%. In this way, the straight line represented by a simple function consisting of the relationship between the nitrogen content of the two sections measured from the leaf blade of the rice by the measuring device 30 and the nitrogen content measured by the camera 2 is actually used. The relationship is clarified, and the nitrogen content measured by the camera 2 is corrected by the simple function. Here, correction is performed by a straight line represented by this function, and this function is stored in the RAM 29 as a correction conversion formula. In FIG. 13, specifically, NO is corrected from 4.2 to 3.0, and NO is corrected from 3.6 to 2.4. Similarly, the values of the other sections are corrected as shown in FIG. 9 based on the correction conversion formula determined by the correlation between the two sections. Thus, third crop information is obtained. Although the obtained third crop information is crop information of nine sections, an average value can be further obtained from the crop information and handled as one crop information in a range photographed by a camera. Although the correction coefficient is represented by a simple function using the representative values of the two sections, the correction coefficient is obtained by the measuring device 30 using the crop information of all the sections photographed by the camera as an explanatory variable. Correlation coefficients obtained from the obtained crop information of all plots as objective variables may be used regardless of whether they are linear or non-linear.

After that, the nitrogen content measured by the camera 2 is corrected by the data processing device 20 based on the correction conversion formula shown in FIG. 12, so that it can be used as a value with further improved measurement accuracy. . This makes it possible to obtain a quicker answer by a simple method of photographing, as compared with a method in which the leaf nitrogen content at a plurality of locations in a field is conventionally obtained only by the measuring device 30. Furthermore, taking into account the fact that researching the nitrogen content of crops by photographing the reference plate and the field is still in the midst of research can greatly contribute to the improvement of measurement accuracy.
The measurement of the nitrogen content by the measuring device 30 is performed in the field 1
It is not necessary to measure the nitrogen content of all the representative crop leaves in the field 1, instead of performing the measurement on all the crop leaves in the field.

It is clear that the crop information obtained from the field 1 in the first and second embodiments for performing the nutrition diagnosis differs depending on the position of the camera 2 with respect to the object. That is, the field 1 here may be a whole field divided by a so-called “ridge”, or may have an area smaller than that of the whole field. When determining the correction value or the correction coefficient, it is important that the information source of the crop information obtained by the camera and the information source of the crop information obtained by the measuring device 30 are in the same field. In addition, the sections in the second embodiment of the nutrition diagnosis are performed by dividing the crop information of the one-side field obtained by one photographing into a plurality of sections.
It is possible to divide the crop information of a smaller area than the one-side field obtained by the above-mentioned photography into a plurality of pieces, and so on. Identity is important.

Next, a third embodiment of the nutritional diagnosis of crops will be described. Here, as a method of obtaining information divided into a plurality of sections from the field 1, the camera 2 obtains the same number of reflected light amounts as the plurality of sections. That is, the difference from the second embodiment of the nutrition diagnosis is that the crop information is individually obtained by the camera 2 from each of the plurality of sections. In this case, the amount of crop information for each section is increased as compared with a case where the crop information of the entire field obtained by one photographing of the second embodiment is divided into a plurality of pieces. The accuracy of the correction coefficient determined by the correlation with the crop information is improved. The determination of the correction coefficient using the crop information of the plurality of sections obtained in this manner is performed by selecting the crop information of two sections from the plurality of sections, preferably the crop information of the section showing the maximum value and the minimum value. Determine the ROM
The storage in the memory 28 and the like are the same as those in the above-described second embodiment, and will not be described. The correction coefficient here may be a correlation coefficient obtained by using the crop information of all the sections taken by the camera as an explanatory variable and the crop information of all the sections obtained by the measuring device 30 as an objective variable, and may be a linear or non-linear correlation. It is the same as in the second embodiment that it can be used without any change.

After that, the nitrogen content measured by the camera 2 is corrected by the data processing device 20 based on the correction conversion formula shown in FIG. . This makes it possible to obtain a quicker answer by a simple method of photographing, as compared with a method in which the leaf nitrogen content at a plurality of locations in a field is conventionally obtained only by the measuring device 30. Furthermore, taking into account the fact that researching the nitrogen content of crops by photographing the reference plate and the field is still in the midst of research can greatly contribute to the improvement of measurement accuracy.
The measurement of the nitrogen content by the measuring device 30 is performed in the field 1
It is not necessary to measure the nitrogen content of all the representative crop leaves in the field 1, instead of performing the measurement on all the crop leaves in the field.

It is clear that the crop information obtained from the field 1 in the third embodiment of the nutrition diagnosis differs depending on the position of the camera 2 with respect to the object. That is, the field 1 here may be a whole field divided by a so-called “ridge”, or may have an area smaller than that of the whole field. In determining the correction coefficient, it is important that the information source of the crop information obtained by the camera and the information source of the crop information obtained by the measuring device 30 are the same section in the same field. In addition, the section in this embodiment captures the crop information of the above-mentioned field as one section by one photographing, and the crop information obtained by one photograph and having an area smaller than that of the above-mentioned field is one section. Catching,
In any case, the identity of the information sources of the crop information to be collected is important in determining the correction value or the correction coefficient.

As described above, the correction for the photographing by the camera 2 can be performed by the area correction, the depression angle correction, and the viewing distance correction. In addition, by using the reference plate 3, an error due to weather such as weather can be corrected, and by using a value of the device 30, an error due to the measurement orientation and the planting density can be corrected. That is, even if the camera is tilted from the ground and the field is photographed diagonally, the correction can be performed in the present invention. When the correction by the device 30 is performed, the value obtained by correcting the weather error due to the reference plate in the measurement by the camera 2 is corrected by the value obtained by directly measuring the crop leaves measured by the same camera 2. Is a value obtained irrespective of the measurement direction and planting density, the value obtained by directly measuring the crop leaves at the value of This value is not affected by many external factors compared to remote sensing.

In collecting crop information by the camera 2 of the above embodiment, not all information obtained by the camera 2 is crop information. In other words, if the data is verified for each pixel of the camera 2, most of the data will be crop information, but in order to obtain the crop information, the crop information will be obtained in a state of looking down naturally, so the soil may be photographed depending on the planting density. There is also. Therefore, in the present invention, pixels that receive crop information and pixels that receive information other than crop information are separated, and only the light reception data of the pixel that receives the crop information is taken in as crop information.

FIG. 14 is a diagram showing changes in the reflectance of soil and crop leaves with respect to wavelength. 750n wavelength
In the range of m to 1300 nm, it has been found that the reflectance of crop leaves causes a difference of about 20% with respect to the reflectance of soil. Therefore, if the reflectance obtained by Expressions 1 and 2 shows a value exceeding, for example, 40%, it is treated as light reception data of a crop leaf, and a value below this value is canceled as not being light reception data of the crop leaf, The received light data exceeding 40% is used as it is, or an average value is obtained for each section and used, and is treated as crop information obtained by the camera 2. For example, it is assumed that light reception data is obtained for a plurality of pixels as shown in FIG. In this case, 1
If it is calculated that the portion represented by the diagonal grid is calculated as a reflectance of 40% or more by the reflected light of the crop leaves and the portion represented by the diagonal lines is calculated as less than 40% in the soil other than the crop leaves, the reflectance is 40 pixels. The light reception data of the pixels which are less than% are canceled out, and those useful as crop information are the light reception data obtained from the shaded pixels in FIG. As described above, in the present invention, the determination of the correction value or the correction coefficient based on the crop information by the camera 2 and the crop information by the measurement device 30 includes:
The selection of light reception data by the camera 2 is added. In this manner, the information selectively obtained by the camera 2 is information obtained only from the crop leaves, and the information obtained from the measuring device 30 is, of course, directly measured from the crop leaves. Nutrition diagnosis of crops can be made accurately using the crop information and the correction value or the correction coefficient.

Although the measurement of the reflected light of the crop leaves by the camera 2 has been described as being obtained by measuring the reflected light of the reference plate, the measurement of the incident light can also be performed in the form of an illuminometer. FIG. 16 shows a simplified illuminometer 93. A filter wheel including a photoelectric conversion unit (silicon sensor) 94 having a spectral characteristic in the near infrared region to the visible light region, and a plurality of narrow band filters 96 for selecting light incident on the photoelectric conversion unit 94 by a stepping motor 97. 95 peripheral parts. The plurality of filters 96 are switched by rotating the filter wheel 95. An opening 98 of a shielding plate is provided on the light receiving surface side (upper part of the drawing) of the photoelectric conversion unit 94, and a diffusion dome 99 formed of a diffusion reflection plate is arranged above the opening 98 with the photoelectric conversion unit 94 as a center. The photoelectric conversion unit 94 and the stepping motor 97 are connected to the control unit 100
The control unit 100 switches the filter 96 by rotating the stepping motor 97, and outputs a signal of the photoelectric conversion unit 94. The type of the filter 96 is the same as the type of the filter 5 of the camera 2. Control unit 1
00 is an I / O port 25 of the data processing device 20 (FIG. 3).
Connected to and controlled. By providing the filter 96 with a filter for shielding light, the zero point correction can be performed by the filter 96.
It becomes possible by switching.

The control unit 100 of the illuminometer 93 uses the signal from the data processing device 20 to switch the filter 96 to the target filter 9.
6, the amount of natural light diffused and reflected from the diffusion dome 99 at this time is detected via the filter 96, and the signal detected by the photoelectric conversion unit 94 is transmitted to the data processing device 20. The data processing device 20 includes an illuminometer 93
By substituting the quantity of light obtained in Equation (5) as the incident light quantity Y instead of the reference plate reflected light quantity P0 into Equation 5, Rij = P ″ ij /
It becomes Y, and the amount of reflected light obtained from the crop leaves can be calculated as the reflectance. When using this illuminometer 93,
The first crop relational expression is obtained based on the reflectance when the illuminometer 93 is the incident light amount.

The whole field can be photographed and corrected in the same manner, and the measurement can be performed at each specific time such as the sprouting stage, which is the time of growing rice, or can be corrected by a method of measuring a part of the field. In this way, it is possible to estimate the nitrogen content of the entire field. This method is more effective if corrections can be made for each variety and each region (for each field). In other words, by storing a plurality of calibration curves for each type, for each region, in the ROM 28, they can be read and used each time. Assuming that the camera 2 in the embodiment has a resolution of about 240,000 pixels and obtains crop information in one shot from the field 10 are 250,
Pixel.

The nitrogen content of the field obtained in this manner is known from the past. For rice, the optimum nitrogen content at any growth stage such as the panicle formation stage and the meiosis stage can be finely classified by cultivar or region. Researched and sought after,
It is possible to compare the nitrogen content based on the corrected first crop information and the third crop information obtained according to the present invention with the reference nitrogen content determined with the growth of the crop determined in the conventional research. The amount of fertilization becomes clearer than the standard, and the amount of fertilization to be applied in the future can be determined according to the amount of nitrogen. The same can be said for the leaf color value, and there is a high correlation between the leaf color value and the leaf nitrogen content, and both show similar changes.
The present invention can be realized even if the method described above is applied to leaf color values. The method described with reference to FIGS. 1 to 3 can be applied not only to the nitrogen content and the leaf color value, but also to the plant height, dry matter, and nitrogen absorption of the crop, and can be applied to crops other than rice.

[0071]

As described above, even in the case of performing nutrition diagnosis by photographing a field from the side of the field, that is, from the ground, a difference in photographing area per unit pixel due to a depression angle and an angle of view generated when the camera is pointed at the field. Can be corrected and the reflected light amount can be further adjusted to a constant area or a predetermined area, so that a nutrition diagnosis with sufficiently high reliability can be performed even when photographing on the ground.

Also, using a camera with a small number of pixels,
Even if there is a difference in the size of the imaging area per pixel, the pixels are divided so that the area is constant, or the pixels are divided so as to have a predetermined area so that the divided area is constant and The data of each pixel can be effectively used.

The nutritional diagnosis of a crop can be easily performed by measuring the reflected light from the leaves of the crop and calculating the nitrogen content of the crop. Is calculated, the nutritional diagnosis of the crop having the high accuracy of performing the nutritional diagnosis of the crop can be performed.

Also, in a simple method of performing a nutritional diagnosis of a crop by measuring the reflected light of the crop leaves and calculating the nitrogen content of the crop, measurement errors due to differences in measurement orientation, leaf fluctuation due to wind, planting density, etc. Can be corrected by the accuracy of performing a nutritional diagnosis of the crop by directly irradiating the crop leaves with light and measuring the reflected or transmitted light to calculate the nitrogen content of the crop. With the method of nutrition diagnosis of crops performed by measuring reflected light, nutrition diagnosis of crops with higher reliability than before has become possible.

[Brief description of the drawings]

FIG. 1 is a layout diagram of a camera and a reference plate installed in a field for measuring reflected light of crop leaves.

FIG. 2 is a schematic block diagram of a camera that measures reflected light from crop leaves.

FIG. 3 is a schematic block diagram of a data processing device.

FIG. 4 is a diagram showing a depression angle, an angle of view, and the like when photographing a field;

FIG. 5 is a diagram showing the pixel coordinates of the image sensor and the size of the imaging area.

FIG. 6 is a diagram showing photographing for determining a correction coefficient for depression angle correction.

FIG. 7 shows the nitrogen content of reflected light obtained from a field divided into a plurality of sections with a fixed area.

FIG. 8 shows the nitrogen content shown by selecting a predetermined area or less from reflected light obtained from a field and dividing the area into a plurality of sections with a predetermined area.

FIG. 9 is a side view in which a part of a main part of the blade nitrogen amount measuring device is broken.

FIG. 10 is a schematic control block diagram of a leaf blade nitrogen amount measuring device.

FIG. 11 is a view showing the operation of a leaf blade nitrogen amount measuring device.

FIG. 12 is a diagram showing a relationship between a blade nitrogen amount measuring apparatus and a nitrogen content rate by photographing.

FIG. 13 is a diagram showing values obtained by correcting nutrition diagnosis in a plurality of sections.

FIG. 14 is a reflectance curve with respect to wavelengths of crop leaves and soil.

FIG. 15 is a diagram showing received light data of crop leaves and soil obtained by a camera.

FIG. 16 is a side sectional view schematically showing an illuminometer for measuring incident light.

[Description of Signs] 1 Field 2 Camera 3 Reference plate 4 Area sensor 5 Narrow band filter 6 Filter wheel 7 Condensing lens 7 8 Control circuit 9 Stepping motor 10 Operation switch 10 20 Data processing device 21 A / D converter 22 Frame memory Reference Signs List 23 Monitor 24 Image processing board 25 I / O port 26 CPU 27 I / F board 28 ROM 29 RAM 30 Leaf nitrogen measuring device 31 Main body 32 Light source 33 Light intensity detecting device 34 LED 35 LED 36 Narrow band filter 37 Narrow band filter REFERENCE SIGNS LIST 38 diffuse reflection plate 39 block 40 reflection light path 41 emission side 42 diffusion transmission plate 43 measuring leaf 44 light quantity detection device 45 arm 46 axis 47 coil spring 48 micro switch 50 analog board 51 light emitting device 52 I / O board 53 CPU board 54 Liquid crystal display LCD 55 Input unit 56 Connection port 57 Power supply board 58 Printer 59 I / F board 60 ROM 61 RAM 93 Illuminance meter 94 Photoelectric conversion unit 95 Filter wheel 96 Narrow band filter 97 Stepping motor 98 Opening 99 Diffusion dome 100 Control unit

Claims (5)

[Claims] 1. A camera having a plurality of pixels is arranged at a predetermined central depression angle with respect to a field, a field is photographed, and the amount of reflected light of a crop leaf is obtained for each unit pixel. The imaging area per unit pixel is obtained by an area function consisting of conversion variables including the number of pixels and the angle of view, the amount of reflected light per unit pixel is corrected for the area by the imaging area, and the largest area among the imaging areas obtained per unit pixel A plurality of pixels are divided based on the photographing area of the unit pixel corresponding to, the reflectance is obtained from the reflected light amount and the reference reflected light amount for each segment, and the reflectance is determined in advance to obtain crop information from the reflectance. First
Crop information of a certain area is obtained from
And diagnosing the nutrition of the field crop from the first crop information. 2. A camera having a plurality of pixels is arranged at a predetermined central depression angle with respect to a field, a field is photographed, and the reflected light amount of a crop leaf is obtained for each unit pixel. The imaging area of each unit pixel is obtained by an area function including a conversion variable including the number of pixels and the angle of view, and the amount of reflected light per unit pixel is corrected for the area by the imaging area. The reflectance is obtained from the reflected light amount of the unit pixel that is equal to or smaller than the imaging area and the reference reflected light amount,
Crop information of a certain area is obtained from the reflectance and a first crop relation formula predetermined for obtaining the crop information from the reflectance, and is defined as first crop information. A method for diagnosing a crop, comprising diagnosing nutrition of the crop. 3. A camera having a plurality of pixels is arranged at a predetermined central depression angle with respect to a field, an image of the field is obtained, and a reflected light amount of a crop leaf is obtained for each unit pixel. The imaging area per unit pixel is obtained by an area function consisting of conversion variables including the number of pixels and the angle of view, the amount of reflected light per unit pixel is corrected for the area by the imaging area, and the largest area among the imaging areas obtained per unit pixel A plurality of pixels are divided based on the area of the unit pixel corresponding to the above, a reflectance is obtained from the reflected light amount and the reference reflected light amount for each segment, and the reflectance is determined in advance to obtain crop information from the reflectance. A crop diagnosing method characterized in that crop information of a fixed area is obtained from the first crop relation formula and used as first crop information, and the nutrition of the field crop is diagnosed based on the first crop information. 4. A camera having a plurality of pixels is arranged at a predetermined central depression angle with respect to a field, and the field is photographed to obtain the amount of reflected light of crop leaves for each unit pixel. The imaging area of each unit pixel is obtained by an area function including a conversion variable including the number of pixels and the angle of view, and the amount of reflected light per unit pixel is corrected for the area by the imaging area. The reflectance is obtained from the reflected light amount of the unit pixel that is equal to or smaller than the imaging area and the reference reflected light amount,
Crop information of a certain area is obtained from the reflectance and a first crop relation formula determined in advance for obtaining crop information from the reflectance, and is used as first crop information. A method for diagnosing a crop, comprising diagnosing nutrition of the crop. 5. A method for storing first crop information, irradiating light to a leaf of a crop having the same area, and measuring light quantity of at least one of transmission and reflection of a wavelength related to the crop information which increases or decreases as the crop grows. Then, crop information is obtained from the light quantity and a second crop relation equation predetermined for obtaining crop information from the light quantity, and stored as second crop information, and the first crop information and the second crop information are obtained. The method for diagnosing a crop according to any one of claims 1 to 4, wherein the nutrition of the field crop is diagnosed based on the information.