JPS5892904A - Surface direction detection method and device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for non-contactly detecting the surface direction of a specific point (hereinafter referred to as a fixed point) on the surface of an object.

Conventionally, Berthold-Horn research has been conducted as a method for non-contactly measuring the direction of a surface from a detected image.

In this method, light is irradiated onto the object from one direction, and the inclination of each point on the reflective surface is determined from a grayscale image obtained by the reflected light.

According to Horn's research, the relationship between the intensity of reflected light and the inclination of a surface can be expressed by a nonlinear first-order partial differential equation involving two unknowns. In order to solve this equation, it is converted into five equivalent ordinary differential equations. Furthermore, points (singular points) where the inclination of the surface can be determined using only local information are searched for in the grayscale image, and the initial curve is calculated using this. Then, by numerically integrating the ordinary differential equation based on this initial curve,
The slope of the surface at each point is successively calculated.

As mentioned above, Horn's method cannot determine the direction of the surface at each point from only local image information, so there are problems such as long processing time and the risk of calculation errors propagating and accumulating. There is.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art and to provide a method capable of quickly calculating the direction of a surface from local information on the intensity of reflected light, as well as an apparatus suitable for implementing the above-mentioned method. .

Next, the basic principle of the method of the present invention will be explained with reference to FIGS. 1 to 4.

FIG. 1 is a chart showing the directional characteristics of reflected light.

When incident light C is irradiated at an angle θ with respect to the direction @H of the diffusely reflecting surface A, the distribution of reflected light intensity is like a reflected light directivity curve,
It forms an ellipse whose major axis is a line E that is symmetrical with the incident light C with respect to the normal B.

(Refer to Figure 2) The direction and intensity of the incident light C are constant, the reflected light observation direction F is fixed, and the diffused reflection image is kept perpendicular to the page.Rotated around the incident point 0 of the incident light C. Then, the reflected light intensity is the modulus of the diffuse reflection surface A! ! (not shown) is the reflected light intensity curve GO. Strong inflection of the reflected light above! 1G is the direction of incident light C and the direction of reflected light observation F.
It forms an oval shape with equal parts &H as long sleeves.

If one tries to calculate the direction of the diffused reflection surface A by measuring the reflected light intensity in the reflected light observation direction F based on FIG. 2, there will be a problem such as a missing part. Reflected light strong inflection @
Although G depends on the surface condition of the material 1 of the diffused reflection surface A, it is generally a bivalent function in the normal direction of the surface A. Therefore, two solutions can be obtained as the direction of the surface where reflected light of a certain intensity is observed. Therefore, the direction of the diffuse reflection surface A cannot be determined based only on local information such as the intensity of reflected light from the incident point (ie, reflection point) 0.

Based on the above considerations, the method of the present invention is based on local information (i.e., the intensity of reflected light from a specific reflection point 0) by emitting light from multiple directions and measuring the reflected light. In order to uniquely detect the direction of the diffusely reflecting surface, and simultaneously project and detect light rays in multiple directions, multiple monochromatic lights with different directions and wavelengths are projected at a specific point. The reflected light is observed from a specific direction, the received light beam is separated into each monochromatic light, the intensity of each is converted into an electrical signal, and the above signals are electrically processed and instantaneously generated. It is characterized by detecting the surface direction of a specific point.

Figure Jig3 is an explanatory diagram of the principle of the method of the present invention.
1. The reflected light observation direction F and the incident point (reflection point) 0 represent the same as in FIG. 2 described above. Therefore, the reflection intensity of the reflected light of incident light C observed from direction F - @G too! It is the same bicurve as in Figure @2. In the □ method of the present invention, another incident light J is irradiated from a direction different from the above-mentioned incident light C toward the above-mentioned specific incident point 0. The reflected light intensity curve when this incident light J is viewed from the observation direction F is as shown by K.

As can be easily understood from this diagram, the specific reflection point 0
If the reflected light intensity of the incident light C and the reflected light intensity of the incident light J are observed from direction F as local information from Accordingly, the direction of the diffused reflection surface A is uniquely determined.

However, the above-mentioned surface direction measurement principle is based on the prerequisite that the diffuse reflection surface A maintains a posture perpendicular to the paper surface, and cannot be applied outside this condition, that is, when the diffuse reflection image is not perpendicular to the paper surface.

When the diffuse reflection image is in an arbitrary direction in a three-dimensional space, the method of the present invention, as shown in FIG. In addition, the reflected light from the specific point 0 is observed from a specific direction F.

In FIG. 3, which is considered in a two-dimensional manner, by determining the direction of the incident light C and the direction F of observing the reflected light, the intensity of the elliptical reflected light -I! In the same way that G was obtained, in Fig. 4, which considers this three-dimensionally, by determining the direction of the incident light C and the direction F of observing the reflected light, a spheroidal reflected light intensity curved surface (Fig. (not shown) is obtained. Similarly, spheroidal reflected light intensity curved surfaces (not shown) are obtained for the incident light J and the same, respectively.

According to the basic principle explained above, when the image to be detected, which is a diffusely reflecting surface in FIG. By irradiating the incident light J and measuring the reflected light intensity in the F direction, it is possible to calculate the direction of the target person. In addition, in FIG. 4, similarly to the above, incident lights C1, J1, and C1 are sequentially irradiated, and the reflection intensity in the F direction is determined. jN#1, it is possible to calculate the three-dimensional direction of the target surface A. The method of the present invention uses multiple types of monochromatic light to achieve the above two
Perform irradiation and observation three times at the same time. Furthermore, by performing the above observation and calculation electrically, the direction of the detection target surface is instantaneously calculated.

When the method according to the present invention described above is applied, it is possible to detect the moment when a moving target surface becomes in a preset direction, and it is also possible to calculate the direction of a moving surface from moment to moment. can.

FIGS. 5 to 8 show examples of surface direction detection devices configured to carry out the method of the present invention, and show the configuration of each device and how the method of the present invention was carried out using each of the above-mentioned devices. An example is given below.

In FIG. 5, the surface of the 21 magnified detection object and the 20 Fi direction are specific points for detection. The object plane 21/Ii in this example includes a straight line d passing through the specific point 20, and rotates around the above straight line Q. FIG. 5 shows an example of a detection device configured to detect when the target surface 21 reaches a specific position T.

A tungsten lamp 2a and a light projection lens 4a are installed on the same optical axis, and an optical filter 3a with a passing wavelength of 45 Q am is interposed between them to constitute a light source 1a that emits a monochromatic parallel light beam with a wavelength of 450 nm.

Similarly, a monochromatic light source 1 with a wavelength of 550 nm is formed by a tungsten lamp 2b, a projection lens 4b, and an optical filter 3b.
Configure b. The original axes of the monochromatic light sources 111 lb are each fixed toward a specific point 20 on the detection target surface 21 .

5 is a light receiver, in which two 7 otomaru 7m and 7b are arranged in a row, sharing an objective lens 6 focused on a specific point 20;
Photomaru 7aiCId Passage wavelength: 450 nm q) Optical filter 8: Passage wavelength: 550 nm
The configuration is provided with optical filters 8b each having a wavelength of 1 nm. Then, the optical axis of the light receiver 50 is fixed so as to be perpendicular to the target surface 21 at the T position and pass through the specific point 20.

The electrical signal outputs of the photomultipliers 7m+7b are inputted to the comparator 10 via amplifiers 9a19b, respectively.

This comparator 10 compares the intensities of both electrical signal outputs and outputs a detection output signal 11 when the two become equal within the allowable tolerance range.

As a result, monochromatic light with a wavelength of 450 nm emitted from the light source 11 is reflected at the specific point 20 and enters the light receiver 5, but since it cannot pass through the optical filter 8b (550 nm), it does not enter the photomultiplier 7b, and the optical filter 13a (45
0 nm) and enters the photomultiplier 7a where it is converted into an electrical signal.

Similarly, monochromatic light with a wavelength of 550 nm emitted from the light source 1b is reflected at a specific point 20, detected only by the 7 otomaru 7b, and converted into an electrical signal.

In this way, two monochromatic light sources 1 with different irradiation directions
The irradiation light beams a+ 1b are individually detected by the photomultipliers 7aw7b without interfering with each other. Due to this effect, it is not necessary to sequentially detect the surface direction using the incident light from two directions as explained with reference to FIG. 3 for the incident light C and the incident light J. Irradiation and detection can be performed simultaneously.

In order to detect that the target surface 21 is at the T position using the device of this embodiment, the target surface is set in advance to the T position, and at this time, the electric signals output from the two photolumes m and 7b are The light source 2m+2 is input to the comparator 1o at the same level.
The luminous intensity of b, the sensitivity of Photomaru 7a, 7b, or increase @
Adjust the increment of 59a and 9b by 11 degrees.

If the direction of the target plane 21 changes after the adjustment as described above, the magnitudes of the two signal outputs input to the comparator 10 will become unequal. Then, when the target surface 21 rotates further and returns to the T position, at that moment the state of the prevention adjustment described above is reproduced, and the two electrical signals input to the comparator 1o become the same level, and the comparator 10. A detection output signal 11 is transmitted.

According to this embodiment, as described above, when the two-dimensionally moving diffusely reflecting surface 21 is used as a target surface, it can be instantaneously detected when this surface moves in a preset direction. .

Fig. 186 differs from the above embodiment in that the implementation device 5 is configured to detect the direction of this surface 2o moment by moment with the diffuse reflection surface 21 moving two-dimensionally as the target surface.
The components are similar to those in FIG. 5). The detection signal outputs of the photomultipliers 7a+7b constituting the light receiver 5 are sent to the automatic computer 1 via A/D converters 12a+12b, respectively.
3. The automatic computer 13 described above is equipped with a reference data storage device 14 .

The automatic computer 13 has an A/D converter 12a and an A/D converter 12a.
It has a function of calculating the relationship between the two signals input from b, that is, the ratio of the strengths of the two signals, and storing the direction of the target surface 21 at that time in the storage device 14 as data in correspondence with this. are doing. Then, when two signals are given, the ratio is calculated, the recorded data in the storage device 14 is searched for surface direction data corresponding to the above ratio, and this data is output as surface direction data No. 15. It also has functions.

In order to continuously detect the direction of the target surface 21 using the device of this example, the direction of the target surface 21 is varied in advance. (
For example, the inclination angle is changed by 1° or 1'). Then, the direction (inclination angle) data of the target surface 21 at that time is stored in the storage device 14 in correspondence with the relationship (ratio) of the signal outputs of the A/D converters 12m and 12b in each direction.
Let me remember it.

After preparing as described above, when the target plane 21 is in an unknown direction, when the signals from the A/D converters 12 and 12b are input to the computer 13, the computer 13 receives two input signals. The ratio is calculated, the recorded data in the storage device 14 is searched, and surface direction data corresponding to the above ratio is transmitted as the surface direction output 15.

In this embodiment, as described above, the direction of this surface can be detected moment by moment by using the diffuse reflection surface 21 that moves two-dimensionally as the target surface.

FIG. 7 shows a further different embodiment, which is a ternary version of the nine embodiments shown in FIG. That is, the embodiment of FIG.
This is configured to detect the moment the target surface 21 whose direction changes dimensionally changes to a preset direction, but in this embodiment (FIG. 7), the target surface 21 is three-dimensional. The device is configured to detect the moment the target surface 21 reaches a preset direction when the direction is changed.

This example is based on the basic principle explained with respect to Fig. 4.
It is constructed in a way that it irradiates monochromatic light with different wavelengths from different directions, extracts and separates the reflected light, converts it into an electrical signal, and electrically processes it.

The light sources 1a and 1b are the same components as in the previous example.

The light source 1C has a structure similar to the light source 1J 1b described above, and an optical filter 3c with a passing wavelength of 650 nm is provided between the tungsten lamp 2c and the lens 4c, so that the wavelength < S5
Constructed so as to be able to irradiate a parallel beam of monochromatic light of 0 nm,
It is fixed toward a specific point 20.

The light receiver 5' is a similar component to the light receiver 5 of the previous example, and is composed of three 7-shaped lenses 7a and 7b17c of the same structure that share the objective lens 6, and are each equipped with an optical filter 8.
It has a+ 8b+ 8c. The above optical filter 8a
t ab is the same component as in the previous example, and is an optical filter 9c#i with a passing wavelength of 650 nrn.

Each of the above-mentioned seven digits 7i, 7b, and 7c inputs the output of the detection signal to the comparator 10 via the amplification Flit 9a+9b+9c. Comparison operator 1 above
o is a component similar to that in the previous example (FIG. 5), and emits a detection output signal 11 when the three signals inputted from the amplifiers 9at9b+9c become equal.

In order to detect the position of the target surface 21 in the direction, for example, T, using the device of this example, the target surface 21 must be set to T in advance.
At this time, the light source, photomultiplier, or amplifier is adjusted so that the signal outputs of the three amplifiers 9199bt9C are at the desired level. Thereafter, when the target surface 21 gradually moves and reaches the T position, the three amplifiers 9a+9
The output of b* 9c becomes the same level, and the comparator 10 outputs the detection output signal 11.

According to this embodiment, when the target surface whose direction changes three-dimensionally as described above reaches a preset direction, this can be immediately detected.

FIG. 8 shows a further different embodiment, and this embodiment is constructed so that the direction of the object surface 21, which changes direction three-dimensionally, can be continuously detected. In this example, the light sources 1a, 1b,
1C and receiver i' are the same components as in the previous example (FIG. 7).

The detection signals of the three 7 digits 7117bl 7C are input to the automatic computer 13 equipped with a storage device 14 via A/D converters 12as 12b+12c, respectively. The computer 13 and storage device 14 described above are similar components to the computer 13 and storage device 14 in the embodiment shown in FIG.

In order to continuously detect the direction of the target surface 21 using the device of this example, the direction of the target surface 21 is varied in advance (for example, every 1' of tilt angle on the Y axis, 1
A/D converter 12a11 that changes in each direction)
The direction of the target surface 21 at that time is stored as data in the storage device 14 in correspondence with the relationship between the output signals of the signals 2b and 12C.

After preparing as described above, when the target surface 21 faces an unknown direction, the detection signals of each photomultiplier 7a+7b+7cO are inputted to the automatic computer 13 via each A/D converter 12a+12b+12c. Calculator 13
Then, the ratio of the above three signals is calculated, the acquisition data in the storage device 14 is searched, surface direction data corresponding to the above ratio is found, and this data is transmitted as the surface direction output signal 15.

According to this embodiment, as described above, it is possible to detect the direction of the target surface, which changes direction three-dimensionally, from time to time.

As shown in the four embodiments described above, the surface direction detection method according to the present invention irradiates monochromatic light of different wavelengths from a plurality of directions toward a specific point, and Out of several types of monochromatic light that are diffusely reflected at one point, only the source reflected in a specific direction is extracted, and this is separated into each monochromatic light and converted into electrical signals, and the above electrical signals are electrically processed. By doing so, the direction of the target surface can be detected immediately and in a non-contact manner based only on the likelihood reflected from the specific one point.

As shown in the embodiments of FIGS. 5 and 7, an apparatus according to the present invention includes: a means for irradiating monochromatic light of different wavelengths toward a specific point from a plurality of directions; means for extracting the original gauze in a specific direction from the diffusely reflected light in the above, means for separating the nine rays obtained by the above extraction means into each monochromatic light, and means for converting the intensity of each separated monochromatic light into an electrical signal. and a means for comparing each of the electrical signals and detecting that these electrical signals have a preset specific relationship, the specific plane is in a preset specific direction. This can be detected immediately, and the method of the present invention described above can be easily implemented to exhibit its effects.

In addition, as shown in the embodiments of FIGS. 6 and 8, the apparatus according to the present invention includes means for irradiating monochromatic light of different wavelengths toward a specific point from a plurality of directions, and means for extracting a light ray in a specific direction from among the diffusely reflected light in the above, means for separating the light ray obtained by the above extraction means into each monochromatic light, and means for converting the intensity of each separated monochromatic light into an electrical signal. , and automatic calculation means for calculating the direction of the target surface at the specific point based on each of the above electric signals, so that when the target surface is in an arbitrary direction, the direction can be detected immediately and continuously. Therefore, the above-described method of the present invention can be easily implemented and its effects can be fully exhibited.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the reflection directivity when the direction of the incident light and the direction of the diffuse reflection surface are constant, and Figures 2 and 3 are when the direction of the incident light and the direction of reflected light observation are constant. A diagram showing the distribution of the reflected light intensity of 5 Figure 4 #'i A perspective view schematically showing the state in which the reflected light of the incident light from 3 directions is observed from a specific direction. Figures 5 to 8 are from this book. FIG. 3 is a diagram schematically showing optical systems of different embodiments of the device according to the invention, with an electrical wiring diagram added to nine perspective views. 1si+ 1b+ ic”・Light source, 2a+ 2bs
2c, -, tungsten lamp, 5a+ 5b+ 5c
m optical filter, 4a+ 4b+ 4c・, lens, 5
．． 5'... Light receiver, 6... Objective lens, 7a17b
17C...Photomaru, Bar 8b+ 8c...
Optical filter, 9s. 9b19C...Amplifier, 10...Comparison calculator, 11
．． 15...Detection 15 output signal, 12a, 12b,
12cm...A/D converter, 15--automatic computer, 14--reference data storage device. Agent Patent Attorney Tadashi Akimoto Figure 1 Figure 3 Figure 5 Figure 6 Figure 3 Figure 7 Figure 8

Claims (1)

[Claims] 1. A method for non-contact detection of the direction of a surface at a specific point on the surface of an object, in which monochromatic light of different wavelengths is irradiated from a plurality of directions toward the specific point. Then, among the diffusely reflected light at a specific point, jt in a specific direction, ! I, the extracted light beam is separated into the plurality of types of monochromatic light, the intensity of each monochromatic light is converted into an electrical signal, and the electrical signal is electrically processed to determine the surface direction of a specific point. A surface direction detection method characterized by detecting. λ A device for detecting the direction of a surface at a specific point on the surface of an object, which includes a means for irradiating monochromatic light of different wavelengths from multiple directions toward the specific point, and a means for irradiating monochromatic light of different wavelengths toward the specific point from multiple directions, and means for extracting rays of direction;
means for separating the light beam obtained by the above extraction means into the plurality of types of monochromatic light; means for converting the intensity of each separated monochromatic light into electrical signals; and means for converting the intensity of each of the separated monochromatic lights into electrical signals; and a means for detecting that these electrical signals have a preset specific relationship by comparing them,
A surface direction detection device characterized by detecting when the direction of the surface at a specific point becomes a preset specific direction. (5) In a device for detecting the direction of a surface at a specific point on the surface of an object, means for irradiating monochromatic light of different wavelengths from multiple directions toward the specific point, and means for extracting rays of direction;
a means for separating the light beam obtained by the above extraction means into the plurality of monochromatic lights, a means for converting the intensity of each separated monochromatic light into an electrical signal, and a means for converting the intensity of each of the separated monochromatic lights into an electrical signal; 1. A surface direction detection device comprising automatic calculation means that receives a signal and calculates the direction of a surface at a specific point, and calculates the direction when the surface of an object is in an arbitrary direction.