CN106770067A - Portable kiwi fruit sugar the cannot-harm-detection device - Google Patents

Abstract

The invention discloses a portable kiwi fruit sugar content non-destructive detection device, which belongs to the field of non-destructive detection of agricultural product spectrum. The technical problem to be solved is to provide a sugar content non-destructive detection device which is suitable for kiwi fruit and has stable detection results. The invention includes a casing, a main control module, a fan, a light source module, a heat insulation baffle, a spectrum detection module, a probe module, a measurement button, a display screen, a power switch, a rechargeable battery and a charging interface. The light emitted by the light source module is injected into the kiwi fruit through the probe module, and diffuse transmission occurs; the diffuse transmission light is transmitted from the probe module to the spectrum detection module, and the main control module controls the spectrum detection module to obtain visible/near-infrared spectral data; the main control module processes the data Finally, the sugar content of the kiwi fruit is obtained and displayed on the display screen. The invention can be used for postpartum grading of kiwi fruit, and can also be used for growth monitoring of kiwi fruit, which helps to improve the detection efficiency of kiwi fruit sugar content and increase economic benefits.

Description

Portable non-destructive testing device for sugar content of kiwi fruit

technical field

The invention relates to the field of spectral non-destructive detection of agricultural products, in particular to a non-destructive detection device for sugar content of kiwi fruit.

Background technique

The kiwi fruit is delicate and juicy, rich in nutrition, and loved by people. my country's kiwifruit planting area is the largest in the world. Sugar content is an important internal quality index of kiwifruit. It is not only an important basis for consumers to choose kiwifruit, but also the main basis for fruit growth monitoring and post-harvest grading. The traditional sugar content of kiwi fruit is measured with a sugar meter. When measuring, the kiwi fruit sample is first squeezed, and then dropped into the sugar meter for detection. The test will damage the kiwi fruit. Therefore, a device that can non-destructively detect the sugar content of kiwi fruit has become an urgent need.

The method of predicting the sugar content of kiwifruit by using visible/near-infrared spectroscopy has the characteristics of convenience, rapidity, non-destructiveness, low cost and environmental friendliness. During the ripening process of kiwifruit, the content of organic molecules will change with the maturity, and the color of the pulp and peel will also change with the maturity. By scanning the visible spectrum, the spectrum containing the color characteristics of kiwifruit pulp and peel can be obtained data. The near-infrared spectral region is consistent with the combined frequency of vibrations of hydrogen-containing groups in organic molecules and the absorption regions of multiple levels of frequency multiplication. These hydrogen-containing groups have strong absorption frequencies and are less affected by the internal and external environments of molecules. The spectral characteristics of samples in the mid-infrared spectral region are more stable. By scanning the near-infrared spectrum, the spectral data containing the characteristic information of the sugar content of kiwifruit can be obtained. Using the visible/near-infrared spectral data and sugar content data of kiwi fruit samples, and through mathematical modeling algorithms, a mathematical model can be established to realize the prediction of kiwi fruit sugar content.

"Research on non-destructive detection technology of kiwifruit near ^- infrared spectroscopy" (Chen Xiangwei; Ph. The detection of the soluble solid content of kiwi fruit is feasible." About 85% of the sugar content is soluble solid content, so the soluble solid content is often used to reflect the sugar content. The article also pointed out: "In the spectral range of 11991.6～5446.2cm ^-1 , there is a significant linear correlation between the near-infrared diffuse reflectance spectrum and the sugar content of kiwifruit". The article also explained in detail the detailed process of using kiwifruit near-infrared spectrum data and sugar content data to establish a kiwifruit sugar content prediction model. The sugar content prediction model of kiwi fruit based on partial least squares (PLS) in this paper has a coefficient of determination R ² of 93.65, and the root mean square error RMSEP of the prediction set is 0.656; the artificial neural network model based on the error back propagation learning algorithm (BP) in this paper , the coefficient of determination R2 is ^89.8273 , and the root mean square error RMSEP of the prediction set is 0.3256.

"Research on Non-destructive Detection Method of Kiwi Fruit Sugar Content Based on Near-Infrared Spectroscopy" (Song Sizhe; Master's Thesis of Northwest Agriculture and Forestry University) pointed out: "The correlation R² between the equatorial sugar content and the total sugar content of kiwi fruit is 0.972, and the sugar content of the fruit handle and the total sugar content of kiwi fruit The correlation R² is 0.945, and the correlation R² between the calyx sugar content and the overall sugar content of kiwifruit is 0.958, and finally the equator is selected as the test site for near-infrared non-destructive detection of kiwifruit sugar content.” The article details the use of partial least squares (PLS), support Vector machine (SVM) and least squares support vector machine (LSSVM) three mathematical modeling methods, with Savitzky-Golay smoothing method (SG) and standard normal variable transformation (SNV) two preprocessing methods and non-informative variable elimination The detailed process of establishing the sugar content prediction model of kiwi fruit with two characteristic wavelength extraction algorithms, UVE and SPA.

"Vis/NIR spectroscopy and chemometrics for the prediction of soluble solids content and acidity (pH) of kiwifruit" (Ali Moghimi et al., Biosystems Engineering) pointed out that it is feasible to use visible/near-infrared spectroscopy to predict kiwifruit internal quality parameters, such as soluble solids content and acidity (pH) of kiwifruit content and pH content; due to the short detection time and low cost of visible/near-infrared spectroscopy detection technology, it is feasible to use this technology to develop non-destructive detection equipment for fruit internal quality characteristics; ) and the partial least squares (PLS) prediction model for kiwifruit soluble solids had a correlation coefficient of 0.93, and a root mean square error (RMSEP) of the prediction set was 0.259.

Although visible/near-infrared spectroscopy has achieved many results in the non-destructive testing of kiwifruit sugar content, the method has not been applied to a portable non-destructive testing device for kiwifruit sugar content in production practice. Traditional spectral detection devices are bulky and expensive, and are only suitable for scientific research institutes and enterprises. At the same time, the complex structure of kiwifruit increases the difficulty of developing kiwifruit nondestructive testing devices. There are small dot-like protrusions on the surface of kiwifruit, the surface roughness is extremely large and covered with plush fibers. The length, thickness, hardness and quantity of plush fibers are related to the variety of kiwifruit; There are light-colored flocs arranged radially and alternately, and a large number of seeds grow on the axis of the fruit; the sugar content of each part of the kiwifruit fruit is also different. When the traditional standard diffuse reflectance optical fiber probe is used to collect the visible/near-infrared spectrum of kiwifruit, the fiber optic probe usually only has a single measuring optical fiber and the diameter of the optical fiber is relatively small, which is easily affected by the structure of kiwifruit, and the stability of spectral data is poor. Multiple measurements near the same measurement point At the same time, when using the traditional diffuse reflectance measurement method, there is a certain distance between the optical fiber probe and the kiwifruit. Although the visible/near-infrared spectrum can penetrate the kiwifruit peel to reach the inside of the fruit, the obtained spectral data directly reflects the kiwifruit. The spectral data accounted for the majority; if the fiber optic probe was placed close to the surface of kiwifruit, the influence of the surface structure of kiwifruit on the spectral data would increase, and the stability of the spectral data would decrease.

Chinese Patent Announcement No. CN 205643156U, announced on October 12, 2016, the patent name is "a portable near-infrared detection device for glucose level", the application discloses "a portable near-infrared detection device for glucose level, including the working object is Grape (0); characterized in that it is provided with a shell (1), an embedded motherboard (2) with Arm architecture, a touch screen (3), an LED light switch (4), a power button (5), a start button (6 ), a power supply battery (7) and a near-infrared sampling module (8); their position and connection relationship are: a round hole is opened in the upper right corner of the front of the casing (1) to install the near-infrared sampling module (8), and the near-infrared sampling module ( 8) There is an LED light switch (4), a power button (5) and a start button (6) at the bottom, a touch display screen (3) is embedded on the left side of the front of the casing (1), and a Arm-based embedded motherboard (2) and power supply battery (7); touch display (3), LED light switch (4), power button (5), start button (6), power supply battery (7) and near-infrared The near-infrared light source (8.3) and detector (8.4) of the sampling module (8) are electrically connected to the embedded motherboard (2) of the Arm architecture." However, this device is a special device designed for glucose level detection and is only suitable for detecting glucose degree, for the kiwi sugar detection powerless; the device is described in the specific embodiment: "detector 8.4 is a spectrum collection device, the main component is an InGaAs/lnAs photodiode, the optical signal is converted into an electrical signal." The main components of the detector are InGaAs/lnAs photodiodes, this type of diode is easily affected by the temperature of the working environment, and the stability of the detection results is difficult to guarantee; the device is a box-type device, and it needs to be kept level and stable when it is used by hand, which is inconvenient to use.

Chinese Patent Announcement No. CN 203732438U, dated July 23, 2014, the patent name is a portable near-infrared detection device, the application discloses "a portable near-infrared detection device, characterized in that it consists of a display (1) , a detection device (2), a near-infrared light source (3) and a microcontroller (4); the device is in the shape of a pistol, and there are buttons (5) on the device; the near-infrared light source (3) passes through the detection device (2) The sample is scanned, and the detection device (2) inputs the scanning signal into the microcontroller (4), and the microcontroller (4) analyzes and processes the received signal and displays it on the display (1)." The patent wants to solve The technical problem is: "The problem that the traditional device is too large to be carried." According to the background technology of the patent: "The near-infrared food quality detection device is based on the various The optical absorption characteristics of a representative organic component in the near-infrared spectral region, the difference in the strongest absorption wavelength of each component, and the direct proportional relationship between the absorption intensity and the organic content of the grain, by comparing the known chemical component content of the sample with its near-infrared spectrum Regression analysis of the measurement results and the establishment of a calibration equation can estimate the content of the same type of unknown sample components.” I learned that the “traditional device” in the technical problem to be solved in this patent refers to near-infrared food quality. detection device. However, there are many types of near-infrared food quality detection devices, and the measurement principles are not the same. The description of the specific implementation of the patent does not provide a complete implementation, does not give a clear description of the detection object and its detection index, and does not give a clear description of the detection object and its detection index. The measurement method and measurement principle are clearly explained, and there are still many unresolved problems; at the same time, there are many kinds of food, and their characteristics such as composition, shape, size, composition and structure are not the same, there are many detection indicators, and there are large differences in detection methods. The structure of a detection device is difficult to adapt to the measurement of various foods and various measurement indicators; therefore, the technical solution described in this patent cannot solve the technical problem of non-destructive detection of kiwifruit sugar content in the present invention. Secondly, the infrared detection device has a compact structure, and a large amount of heat will be generated when the near-infrared light source and the microcontroller work, and the infrared detection device includes a photoelectric sensor. The patent does not provide a solution to this problem for a specific range of working temperature; the display is on the right side of the device, and the user cannot directly observe the display results, which brings inconvenience to use.

Chinese Patent Announcement No. CN 2779390Y, announcement date May 10, 2006, the patent name is "diffuse reflection detection device for near-infrared fruit sugar acidity analysis", the application discloses "diffuse reflection detection device for near-infrared fruit sugar acidity analysis, It is characterized in that it consists of a near-infrared detection optical fiber, an optical fiber bracket, a fruit rotating device and a base. The near-infrared detection optical fiber (2) is composed of a light source input optical fiber and a signal receiving optical fiber. It is a bifurcated optical fiber, and one end of the optical fiber is opened. The fork is respectively connected to the infrared light source (1) and the detector (12), and the infrared light source (1) and the detector (12) are installed in an FT-IR spectrum detection device (13); the other end is a coaxial The optical fiber probe (9), the center of the optical fiber probe (9) is the light source input optical fiber, the surrounding is the signal receiving optical fiber, and the fruit rotating device is a fixture device installed on the base (3) that can control the fruit rotating." The application did not describe the recent The structure of the infrared detection optical fiber probe part, it is impossible to know from the application whether the near-infrared detection optical fiber meets the requirements of kiwi infrared spectrum data collection; the device only completes the spectral data detection work, and also needs to transmit the data to the computer data acquisition system For further analysis, the sugar content data of the test sample cannot be directly obtained, and the structure is too complicated to be used portablely.

In summary, at this stage, the use of visible/near-infrared spectroscopy can achieve the purpose of non-destructive detection of kiwifruit sugar content, but this method has not been applied to the portable non-destructive detection device of kiwifruit sugar content in production practice; at the same time, due to the complex structure of kiwifruit, traditional standards The measurement results of the diffuse reflectance optical fiber have poor stability and cannot be used for the collection of kiwi fruit visible/near-infrared light data; the portable detection devices described in the current related patents cannot solve the problem of non-destructive detection of kiwi sugar content, and these devices do not consider the impact of the probe structure on the measured sample. The applicability and stability of the measurement results are not considered, and the influence of the heat generated by the light source and other devices on the spectral detection device is not considered, so the stability of the measurement results is difficult to guarantee.

Contents of the invention

The technical problem to be solved by the present invention is to provide a sugar content non-destructive detection device which is suitable for kiwi fruit and has stable detection results.

Technical scheme of the present invention is as follows:

Portable non-destructive detection device for sugar content of kiwi fruit, including housing, main control module, light source module, spectrum detection module, probe module, measurement button, display screen, power switch, rechargeable battery, charging interface, the above main control module is connected with the above display screen, the above The power switch, the above-mentioned rechargeable battery, the above-mentioned measurement button, the above-mentioned light source module, and the above-mentioned spectrum detection module are connected. The above-mentioned charging interface is connected to the above-mentioned rechargeable battery. The light source module is connected, and the above-mentioned probe is connected with the above-mentioned spectral detection module through the above-mentioned detection optical fiber.

The spectrum acquired by the above-mentioned spectrum detection module is a visible/near-infrared spectrum. The above-mentioned light source module is a halogen tungsten lamp capable of emitting full-spectrum light.

The above-mentioned detection optical fiber is a quartz optical fiber, and the probe end of the detection optical fiber is covered with a metal inner cylinder, and a condenser lens is fixed in the metal inner cylinder by a condenser lens pressure ring. Above, the other end of the detection fiber is connected to the spectrum detection module through a detection fiber connector.

The above-mentioned illuminating optical fiber is composed of quartz optical fiber bundles, the probe ends of the illuminating optical fiber are arranged in a ring outside the above-mentioned metal inner cylinder and the outer layer is covered with a metal outer cylinder, the end face of the above-mentioned metal inner cylinder is higher than the end face of the above-mentioned metal outer cylinder, and the above-mentioned lighting optical fiber The light source ends are closely arranged in a column, and the outside is covered with a metal shell. The metal shell is fixed with a coupling lens by a coupling lens pressure ring. The center line of the coupling lens coincides with the center line of the light source end of the above-mentioned lighting fiber. Connect with the above light source module.

Ventilation holes are provided on the above-mentioned housing, a heat insulation baffle is provided between the above-mentioned light source module and the above-mentioned spectrum detection module, a fan is provided at the rear end of the above-mentioned light source module, and the fan is connected to the above-mentioned main control module, and the position of the above-mentioned ventilation hole is in the same position as the above-mentioned housing The position of the fan inside corresponds to the position of the light source module, and the fan takes the heat generated by the light source module to the outside of the housing through the vent hole. The above-mentioned spectrum detection module is located at the front end inside the above-mentioned housing, away from the above-mentioned light source module and the above-mentioned main control module.

The outer shape of the above-mentioned casing is similar to the shape of a pistol. Except that the front end of the probe module is located outside the shell, other parts of the probe module are located inside the shell; the probe is located at the front end inside the shell, and the position of the probe is similar to the position of the barrel of a pistol. The handle of the above-mentioned housing has a streamlined shape, the above-mentioned rechargeable battery is fixed inside it, the above-mentioned charging interface is fixed on the lower end of the handle, and the above-mentioned measurement button is fixed near the first joint of the index finger when the handle is held by a human hand. The measurement button The position of the gun is similar to that of a pistol trigger. The above-mentioned display screen is located at the rear end of the above-mentioned housing, and the position of the display screen is similar to that of a pistol hammer, which is close to the user and directly faces the user. The above-mentioned power switch is located at the rear end of the above-mentioned casing, adjacent to the above-mentioned display screen and below the above-mentioned display screen. The above-mentioned power switch, the above-mentioned display screen, the above-mentioned main control module, the above-mentioned fan, the above-mentioned light source module, the above-mentioned heat insulation baffle, the above-mentioned spectrum detection module, and the above-mentioned probe module are respectively fixed in the interior of the upper part of the above-mentioned housing from left to right.

During the measurement, the above-mentioned probe is attached to the kiwi fruit under test, the light emitted by the above-mentioned light source module passes through the kiwi fruit peel and enters the inside of the kiwi fruit through the above-mentioned illumination fiber, and the light is diffusely transmitted inside the kiwi fruit, and the diffusely transmitted light passes through the kiwi fruit peel and is transmitted by the above-mentioned detection optical fiber. transmitted to the above-mentioned spectral detection module, and the above-mentioned main control module controls the above-mentioned spectral detection module to obtain spectral data.

The main control module processes the acquired data to obtain the kiwi sugar content value and displays it on the display screen. In the data processing process, the sugar content prediction model of kiwifruit established in the computer and imported into the above-mentioned main control module needs to be used. The modeling methods of this model are various, mainly including partial least square method (PLS) and support vector machine (SVM). , Error backpropagation learning algorithm (BP).

Compared with the prior art, the present invention has the advantages of:

The above-mentioned spectral detection module cooperates with the above-mentioned light source module and the above-mentioned probe module to obtain the visible/near-infrared spectrum of kiwifruit, and the amount of information related to the sugar content of kiwifruit in the spectrum increases, which is conducive to improving the prediction accuracy of the kiwifruit sugar content prediction model;

The above-mentioned illumination optical fiber fully injects the light generated by the above-mentioned light source module into the interior of the kiwi fruit, increasing the penetration range of the diffuse transmitted light, increasing the sugar content information of the kiwi fruit contained in the diffuse transmitted light, and the stability of the spectral data is not affected by the complex internal structure of the kiwi fruit;

The above-mentioned probe is equipped with the above-mentioned condenser lens, which expands the measurement range of the above-mentioned probe. The stability of the spectral data is not affected by the complex structure of the kiwifruit surface. The increase of kiwi fruit sugar content information is beneficial to improve the prediction accuracy of the kiwi fruit sugar content prediction model;

Since the above-mentioned probe is close to the kiwifruit to be tested during the measurement, the light in the above-mentioned illumination fiber cannot be directly reflected by the kiwifruit peel and then enters the above-mentioned detection fiber, and the diffuse transmitted light of the peel in the obtained kiwifruit visible/near-infrared spectrum is reduced, and the diffuse transmitted light of the pulp is reduced. increase, the information content of pulp sugar content in the spectral data is improved, which is conducive to improving the prediction accuracy of the kiwifruit sugar content prediction model;

Therefore, this technical scheme can improve the stability of kiwifruit visible/near-infrared spectrum measurement results, and at the same time increase the content of sugar content information in the visible/near-infrared spectrum of kiwifruit, and improve the detection accuracy of sugar content; this technical scheme does not damage the tested kiwifruit and meets Non-destructive testing requirements for sugar content of kiwi fruit.

The above-mentioned spectrum detection module is located at the front end of the above-mentioned housing, away from heat-generating components such as the above-mentioned light source module and the above-mentioned main control module; the above-mentioned heat insulation baffle is located between the above-mentioned light source module and the above-mentioned spectrum detection module, preventing heat from being transmitted to the above-mentioned spectrum detection module; The above-mentioned fan brings the heat generated by the above-mentioned light source module to the outside of the above-mentioned casing through the above-mentioned ventilation hole, so as to prevent heat accumulation from causing the internal temperature of the above-mentioned casing to continue to rise; The above-mentioned spectral detection module produces an influence, and the stability of the measurement result is guaranteed.

The shape of the above casing is similar to the shape of a pistol, and has a streamlined handle, which is convenient for the user to hold; the position distribution of each part in the above casing is reasonable, eliminating the need to fix the probe position separately for traditional fiber optic probes, and the above measurement buttons are located at Within the movement range of the human index finger, the user can complete the measurement operation with one hand, and the normal operation of the above-mentioned light source module, the above-mentioned fan, the above-mentioned ventilation hole and the above-mentioned spectrum detection module will not be hindered when the human hand holds it, and the measurement results can be read directly from the above-mentioned display screen. Pick. Therefore, the arrangement of the components in the present invention conforms to the principles of ergonomics and is convenient for users to operate.

The invention has a built-in rechargeable battery, is convenient to use, has a compact structure, is small in size, and is easy to carry, and can be carried in fields, factories and other outdoors for use.

reference sign

1. Shell; 1-1. Vent; 2. Main control module; 3. Fan; 4. Light source module; 5. Heat insulation baffle; 6. Spectrum detection module; 7. Probe module; 7-1. Probe; 7-1-1. Metal outer cylinder; 7-1-2. Metal inner cylinder; 7-1-3. Condenser lens pressure ring; 7-1-4. Condenser lens; 7-2. Detection optical fiber; 7 -2-1. Detection optical fiber connector; 7-3. Illumination optical fiber; 7-3-1. Metal shell; 7-3-2. Coupling lens pressure ring; 7-3-3. Coupling lens; 8. Measurement button; 9. Display; 10. Power switch; 11. Rechargeable battery; 12. Charging interface; 13. Kiwi.

Description of drawings

Fig. 1 is the front view of the portable kiwifruit sugar content non-destructive testing device;

Fig. 2 is the left view of the portable kiwi fruit sugar content non-destructive testing device;

Fig. 3 is the right view of the portable kiwifruit sugar content non-destructive testing device;

Fig. 4 is a diagram of the internal structure of the portable non-destructive detection device for sugar content of kiwifruit;

Fig. 5 is a front view of the probe module of the portable kiwi fruit sugar content non-destructive testing device;

Fig. 6 is a probe structural diagram;

Fig. 7 is a structural diagram of a light source end of an illumination optical fiber;

Figure 8 is a working principle diagram of the probe;

Fig. 9 is a circuit diagram of a portable kiwifruit sugar content non-destructive testing device;

Figure 10 is the visible/near-infrared spectrum of kiwifruit obtained by the portable kiwifruit sugar non-destructive testing device.

detailed description

Below in conjunction with a preferred embodiment and accompanying drawing, the present invention will be further described:

As shown in Figure 4, the portable non-destructive detection device for sugar content of kiwifruit includes: shell 1, main control module 2, fan 3, light source module 4, heat insulation baffle 5, spectrum detection module 6, probe module 7, measurement button 8, display screen 9. The power switch 10, the rechargeable battery 11, and the charging interface 12, the above-mentioned main control module 2 are respectively connected with the above-mentioned power switch 10, the above-mentioned display screen 9, the above-mentioned rechargeable battery 11, the above-mentioned measurement button 8, the above-mentioned fan 3, the above-mentioned light source module 4, The spectrum detection module 6 is connected to each other, and the charging interface 12 is connected to the rechargeable battery 11 .

The probe module 7 includes a probe 7-1, a detection fiber 7-2, and an illumination fiber 7-3. The probe 7-1 is connected to the light source module 4 through the illumination fiber 7-3, and the probe 7-1 is connected to the light source module 4 through the detection fiber. 7-2 is connected to the above-mentioned spectral detection module 6. The front view of the above-mentioned probe module 7 is shown in FIG. 5 . The structural diagram of the above-mentioned probe 7-1 is shown in FIG. 6 . The structural diagram of the light source end of the above-mentioned illumination optical fiber 7-3 is shown in FIG. 7 .

The circuit diagram of the portable kiwi sugar non-destructive testing device is shown in Figure 9.

The above-mentioned main control module 2 adopts Raspberry Pi Zero development board, and the main control chip is Broadcom BCM2835 chip with ARM11 architecture. The development board provides 40 GPIO interfaces, including two sets of SPI interfaces, two 5V power supply interfaces, one 3.3V power supply interface, 5 GND interfaces, and 8 common GPIO interfaces. The development board reserves a Micro-USB data interface. The development board requires a working voltage of 5V. The operating system of the development board is the Raspbian operating system based on the Linux kernel, and the program development language is Python.

The above-mentioned fan 3 is a JMC 3010-5LS DC 5V miniature axial flow fan.

The above-mentioned light source module 4 is a miniature tungsten-halogen bulb with a rated voltage of 5V and a rated current of 1.2A, which can emit light in the full spectrum wavelength range. The light source module 4 is connected to the above-mentioned main control module 2 through a relay, and the on-off of the relay is controlled by the above-mentioned main control module 2 .

The above-mentioned heat insulation baffle 5 is selected from an airgel plate with good heat insulation effect, and its thickness is 10 mm.

The above-mentioned spectral detection module 6 is an Ocean Optics STS module, which can obtain 600-1100nm spectral data in conjunction with the above-mentioned light source module 4 in the full spectral band, and the spectral detection range involves visible/near-infrared bands. The number of sampling points is 1024, which helps to improve the detection accuracy. The working temperature of the module is 0~50°C, the optical fiber connector is SMA905 connector, the data and power supply interface is Micro-USB interface, and the module is connected to the above-mentioned main control module 2 through the Micro-USB data cable.

The above-mentioned measurement button 8 is a tact switch, connected in parallel with a 0.1uF capacitor, and then connected to the above-mentioned main control module 2 to realize hardware elimination of button vibration.

The above-mentioned display screen 9 is a 1.3-inch OLED 12864 display screen. The display screen 9 has the characteristics of small size, self-illumination, and clear display content. It can be used under strong direct sunlight or at night when there is insufficient light. The display screen 9 is connected with the above-mentioned main control module 2 through the SPI interface in the above-mentioned main control module 2 .

Above-mentioned power switch 10 selects self-locking switch for use.

Above-mentioned rechargeable battery 11 selects 18650 type lithium ion rechargeable battery for use.

The charging interface 12 is a Micro-USB interface.

The above-mentioned detection optical fiber 7-2 is a quartz optical fiber, and the outside of the probe end of the detection optical fiber 7-2 is covered with a metal inner cylinder 7-1-2. -1-3 is fixed with a condenser lens 7-1-4, the diameter of the inner circle of the pressure ring 7-1-3 of the condenser lens is 3mm, and the focal point of the condenser lens 7-1-4 is located at the detection optical fiber 7-2 On the end face of the probe end, the other end of the above-mentioned detection optical fiber 7-2 is connected to the above-mentioned spectral detection module 6 through the detection optical fiber connector 7-2-1. Module 6 connectors match.

The above-mentioned illumination optical fiber 7-3 is composed of quartz optical fiber bundles, and the probe ends of the illumination optical fiber 7-3 are arranged in a ring on the outside of the above-mentioned metal inner cylinder 7-1-2 and the outer layer is covered with a metal outer cylinder 7-1-1. The end face of the metal inner cylinder 7-1-2 is 0.5mm higher than the end face of the above-mentioned metal outer cylinder 7-1-1, the difference between the inner and outer circle diameters of the probe end ring of the above-mentioned illumination fiber 7-3 is 4mm, and the above-mentioned illumination fiber 7- The difference between the inner circle diameter of the probe end ring of 3 and the inner circle diameter of the above-mentioned focusing lens pressure ring 7-1-3 is 4mm. The light source ends of the above-mentioned illumination optical fibers 7-3 are closely arranged in a column shape, and the outside is covered with a metal shell 7-3-1, and the metal shell 7-3-1 is fixed by a coupling lens pressure ring 7-3-2 and a coupling lens 7-3 -3, the centerline of the coupling lens 7-3-3 coincides with the centerline of the light source end of the illumination fiber 7-3, and the illumination fiber 7-3 is connected to the light source module 4 through the metal shell 7-3-1.

The casing 1 is provided with ventilation holes 1-1, the above-mentioned heat insulation baffle 5 is provided between the above-mentioned light source module 4 and the above-mentioned spectrum detection module 6, the above-mentioned fan 3 is provided at the rear end of the above-mentioned light source module 4, and the fan 3 is connected to the above-mentioned The main control module 2 is connected, and the position of the above-mentioned ventilation hole 1-1 corresponds to the position of the above-mentioned fan 3 and the above-mentioned light source module 4 inside the above-mentioned housing 1, and the above-mentioned fan 3 passes the heat generated by the above-mentioned light source module 4 through the above-mentioned ventilation hole 1-1 Take to the outside of enclosure 1 above. The spectrum detection module 6 is located at the front end of the housing 1 , away from the light source module 4 and the main control module 2 .

The outer shell 1 has a shape similar to that of a pistol. The above-mentioned probe module 7 except that the front end of the above-mentioned probe 7-1 is located outside the above-mentioned housing 1, and other parts are all located inside the above-mentioned housing 1; the above-mentioned probe 7-1 is located at the front end of the above-mentioned housing 1, and the position of the probe 7-1 is similar to Pistol barrel position. The protruding length of the front end of the probe 7-1 is 1 cm. The handle of the above-mentioned housing 1 has a streamlined shape, the above-mentioned rechargeable battery 11 is fixed inside it, the above-mentioned charging interface 12 is fixed on the lower end of the handle, and the above-mentioned measurement button 8 is fixed at the first joint of the index finger when the handle is held by a human hand , the position of the measurement button 8 is similar to the position of the pistol trigger. The above-mentioned display screen 9 is located at the rear end of the above-mentioned housing 1, the position of the display screen 9 is similar to that of a pistol hammer, its position is close to the user, and directly faces the user. The power switch 10 is located at the rear end of the housing 1 , adjacent to the display screen 9 and below the display screen. The above-mentioned power switch 10, the above-mentioned display screen 9, the above-mentioned main control module 2, the above-mentioned fan 3, the above-mentioned light source module 4, the above-mentioned heat insulation baffle 5, and the above-mentioned spectrum detection module are respectively fixed from left to right inside the upper part of the above-mentioned housing 1. 6. The probe module 7 mentioned above.

During measurement, the above-mentioned probe 7-1 is placed close to the kiwifruit to be tested, and the light emitted by the above-mentioned light source module 4 passes through the kiwifruit peel through the above-mentioned illumination fiber 7-3 and enters the inside of the kiwifruit, and diffuse transmission occurs. The above-mentioned detection optical fiber 7-2 is conducted to the above-mentioned spectrum detection module 6, and the above-mentioned main control module 2 controls the above-mentioned spectrum detection module 6 to obtain spectrum data. FIG. 8 is a working principle diagram of the above-mentioned probe 7-1. Figure 10 is the visible/near-infrared spectrum of 20 "Xuxiang" kiwifruits obtained by using the portable non-destructive detection device for sugar content of kiwi. Able to complete kiwifruit visible/near-infrared spectrum data collection.

The main control module 2 processes the acquired data to obtain the sugar content of kiwi fruit and displays it on the display screen 9 .

In order to complete the function of kiwi fruit sugar detection, it is also necessary to establish a kiwi fruit sugar detection model based on visible/near-infrared spectroscopy. There are many modeling methods, and one of them is explained here:

1. Obtain modeling data:

Collect 40 kiwifruit samples of "Huayou", "Xuxiang" and "Xixuan" three varieties, 120 in total, 10 samples for each variety each week, 30 in total, and two for each kiwifruit for measurement point, the measurement point is located at the equator of kiwifruit, scan the visible/near-infrared spectrum and measure the sugar content, and obtain the visible/near-infrared spectrum data and sugar content data of 240 measurement points in total. Sugar content measurement was measured using ATAGO PR-101α sugar content meter. The above data collection method can increase the distribution range of sugar content data, which is conducive to improving the prediction effect of the model.

2. Establish sugar content prediction model:

In the computer, using MATLAB software, the sample division method uses the random sample division method (RS), divides the modeling data into a training set and a prediction set according to a ratio of 3:1, and uses the partial least square method (PLS) to establish a kiwifruit sugar content prediction Model.

3. Import the model:

The sugar content prediction model obtained by partial least squares (PLS) can be expressed as:

y=Xβ+ε

Where: X is the input data matrix, β is the coefficient matrix, ε is the residual matrix, and y is the sugar content. In the computer, the above formula is realized by using the Python programming language and embedded into the above main control module 2 to complete the import work. The spectral data obtained by the above-mentioned spectral detection module 6 is used as the input data matrix X, which is input into the above-mentioned main control module 2, and y, which is the sugar content of kiwifruit, can be obtained after operation, and is displayed on the above-mentioned display screen 9 .

Instructions:

1. Press the power switch 10;

2. Attach the probe 7-1 to the tested kiwi fruit sample, and select the equatorial position of the kiwi fruit as the measurement point;

3. Press the measurement button 8, and wait for the spectrum measurement to be completed, the waiting time is about 2s;

4. The sugar content value of the tested kiwi fruit sample is displayed on the display screen 9 .

The above embodiment is only an illustration of the present invention, and does not constitute a limitation to the protection scope of the present invention. Any design that is the same or similar to the present invention falls within the protection scope of the present invention.

Claims (5)

1. Portable non-destructive detection device for sugar content of kiwifruit, characterized in that it includes a casing (1), a main control module (2), a light source module (4), a spectrum detection module (6), a probe module (7), and a measurement button (8) , display screen (9), power switch (10), rechargeable battery (11), charging interface (12); The main control module (2) is respectively connected with the power switch (10), the display screen (9), the rechargeable battery (11), the measurement button (8), the light source module (4), The spectrum detection module (6) is connected, and the charging interface (12) is connected to the rechargeable battery (11); The spectrum acquired by the spectrum detection module (6) is a visible/near-infrared spectrum; The probe module (7) includes a probe (7-1), a detection fiber (7-2), and an illumination fiber (7-3), and the probe (7-1) communicates with the illumination fiber (7-3) The light source module (4) is connected, and the probe (7-1) is connected to the spectral detection module (6) through the detection optical fiber (7-2); The detection optical fiber (7-2) is a quartz optical fiber, and the outer side of the probe end of the detection optical fiber (7-2) is covered with a metal inner cylinder (7-1-2), and the metal inner cylinder (7-1-2 ) is fixed with a condenser lens (7-1-4) by a condenser lens pressure ring (7-1-3), and the focal point of the condenser lens (7-1-4) is located at the detection fiber (7- 2) On the end surface of the probe end, the other end of the detection fiber (7-2) is connected to the spectrum detection module (6) through the detection fiber connector (7-2-1); The illumination optical fiber (7-3) is composed of quartz optical fiber bundles, and the probe ends of the illumination optical fiber (7-3) are arranged in a ring on the outside of the metal inner cylinder (7-1-2) and the outer layer is covered with metal The outer cylinder (7-1-1), the end surface of the metal inner cylinder (7-1-2) is higher than the end surface of the metal outer cylinder (7-1-1), the light source of the illumination fiber (7-3) The ends are closely arranged in a column shape, and the outer side is covered with a metal casing (7-3-1). The coupling lens (7-3-1) is fixed by the coupling lens pressure ring (7-3-2) in the metal casing (7-3-1). 3-3), the centerline of the coupling lens (7-3-3) coincides with the centerline of the light source end of the illumination fiber (7-3), and the illumination fiber (7-3) passes through the metal casing (7-3-1) connected with the light source module (4); A heat insulation baffle (5) is provided between the light source module (4) and the spectrum detection module (6), a fan (3) is provided at the rear end of the light source module (4), and the housing (1) Ventilation holes (1-1) are arranged on it. 2. The portable non-destructive detection device for sugar content of kiwi fruit according to claim 1, characterized in that: the outer shell (1) has a shape similar to a pistol, the outer shell (1) has a handle with a streamlined shape, and the inside of the handle is The rechargeable battery (11) is fixed, the charging interface (12) is fixed at the lower end of the handle, and the measurement button (8) is fixed near the first joint of the index finger when the handle is held by a human hand , the position of the measurement button (8) is similar to the position of the pistol trigger, the display screen (9) is located at the rear end of the housing (1) and directly faces the user, the position of the display screen (9) is similar to The position of the pistol hammer, the power switch (10), the display screen (9), the main control module (2), the fan (3), The light source module (4), the heat insulation baffle (5), the spectral detection module (6), and the probe module (7). 3. The portable non-destructive testing device for sugar content of kiwi fruit according to claim 1, characterized in that: in the probe module (7), except that the front end of the probe (7-1) is located outside the casing (1), other Parts are all located inside the shell (1), the probe (7-1) is located at the front end inside the shell (1), and the position of the probe (7-1) is similar to the position of the barrel of a pistol. 4. The portable non-destructive detection device for sugar content of kiwi fruit according to claim 1, characterized in that: the spectral detection module (6) is located at the front end inside the housing (1), away from the light source module (4) and the Main control module (2). 5. The portable kiwi fruit sugar content non-destructive testing device according to claim 1, characterized in that: the fan (3) is connected to the main control module (2).