JPH0245709A - Visual sensing device for robot - Google Patents

Abstract

PURPOSE:To speed up an operation by using a readout control means which varies the scanning line readout order of one right or left CCD element and a couple of space optical modulating elements whose reflection factors are controlled with charges of the right and left CCD elements. CONSTITUTION:Scattered light obtained from an object irradiated with the sunshine, etc., is converged by condenser lenses 11 and 12 and light-received by the CCD elements 13 and 14. here, scanning lines are read out by the readout control means 17 and their charges are applied to lines of the space optical modulating elements 15. The charges vary the transmissivity of the liquid crystal array layer of the element 15. Further, the charges of the element 14 are applied to lines of the space optical modulating element 16 and the transmissivity of its liquid crystal array layer is varied. Then the elements 15 and 16 are irradiated with the beam which is collimated by a collimator lens 19 through a beam splitter 20 and half-mirrors 21 and 22. Then the quantities of reflected light beams from the elements 15 and 16 are detected by a photodetector 23. Then the means 17 applies scanning lines to the element 15 and the quantities of reflected light beams from the elements 15 and 16 are detected by a detector 23.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to the visual field of robots, and in particular to a passive binocular stereoscopic vision system for robots that performs three-dimensional spatial recognition using external light without using a special light source such as a laser. It concerns the visual apparatus.

BACKGROUND OF THE INVENTION Conventionally, two types of visual devices for robots that perform three-dimensional spatial recognition have been proposed, which are called binocular stereopsis systems that perform three-dimensional spatial recognition using the left and right eyes. One of them uses one of the left and right eyes as a laser oscillator and the other as a light receiver, and has the advantage that signal processing is easy because the gaze points of both eyes are fixed at one point on the object.

However, the range of laser light is practically limited to several tens of meters, so when used as a visual device for recognizing the surrounding environment in a self-propelled robot, for example, the disadvantage is that the range of use is limited in terms of distance. It had Therefore, visual devices called passive binocular stereopsis that use external light such as sunlight and illumination light are often used for such purposes.

The configuration of a conventional passive binocular stereoscopic viewing device will be explained based on FIG. 1 is the first camera lens, 2 is the second camera lens, 3 is the first CCD element arranged at the imaging position of the first camera lens 1, and 4 is the imaging position of the second camera lens 2. 5 is a correlation processing means for performing correlation processing of the output signals of the first and second CCD elements by a computer, and 6 is an object.

Next, the operation of this passive binocular stereoscopic viewing device is shown in Figures 4 and 5.
This will be explained using figures. In FIG. 5, L is the center of the first camera lens, R is the center of the second camera lens, fl and f2 are the focal lengths of the first and second camera lenses, respectively, 0 is a point on the object 6, θ and Φ are the base line LR and principal ray OL, respectively.
If D is the angle formed by the chief ray OR and the length of the base line LR, then the distance to the point O is expressed by equation (1).

h=DtarretanΦ(tane+tanΦ)
---(1) Here, tanθ and tanΦ are each 4 equations (2
), (3).

tanθ=fl/di ---(2) tan
Φ=f2/d2 --- (3) However, d
1: distance between L and beam detection point P1 on CCD element 3; d2: distance between R and beam detection point P2 on CCD element 4.

In such a passive binocular stereoscopic device, D, fl
Since dl and f2 are known, the distance to the object 6 can be obtained by finding dl and d2.

Therefore, a cross-correlation calculation of the outputs of the CCD element 3 and the CCD element 4 is performed using the correlation processing means 6, and a beam detection point where the correlation between the output signals of both is high is determined by each CCD element corresponding to the point O on the object 6. The beam detection point on element 3 and the beam detection point on CCD element 4, that is, corresponding points on the left and right, are expressed as equation (1
) to (3) can be used to find the distance to the object 6, and using this it is possible to perform three-dimensional spatial recognition.

Problems to be Solved by the Invention However, in the configuration described above, cross-correlation processing is executed by computer processing, but not only does it require a large amount of memory, but it also takes a long processing time and consumes a lot of power. However, there were problems such as the large size of the image, making it difficult to use it as a visual device for robots.

In view of this problem, the present invention provides a readout control means that makes the scanning line readout order of one of the left and right CCD elements variable;
By using a pair of spatial light modulators whose reflectances are controlled by the charge of the CD element, cross-correlation calculations for determining left and right corresponding points are optically executed, resulting in high speed and low power consumption. The purpose of this invention is to provide a visual device for robots.

Means for Solving the Problems The present invention comprises a pair of left and right condensing lenses spaced apart by a certain distance;
first and second CCD elements disposed at the imaging positions of the pair of condensing lenses, readout control means for varying the order of reading out scanning lines of the first CCD elements, and the first and second CCD elements.
a pair of spatial light modulators each having a reflectance controlled by the charge of a CCD element, and a light source; the light from the light source is divided and irradiated onto the pair of spatial light modulators, and each reflected light is This is a visual device for a robot, characterized by comprising an optical system for superimposing the above-mentioned superimposed light, and a light detection means for detecting the amount of the superimposed light.

Operation With the above-described configuration, the readout control means reads the first CCD.
Superimposing the reflected light from the spatial light modulation element recorded by sequentially changing the scanning line readout order of the photographed image of the element and the spatial modulation element in which the photographed image of the second CCD element is written, and detecting the amount of light. The cross-correlation processing of the output signals of the first and second CCD elements can be performed sequentially optically, thereby providing a high-speed and low power consumption robot visual device.

Embodiment The structure of a first embodiment of the present invention will be explained with reference to FIGS. 1 and 2. FIG. 1 is a plan view of a first embodiment of the invention. Reference numeral 11 denotes a first condenser lens, 12 a second condenser lens arranged at a certain distance from the first condenser lens 11, and 13 placed at an image forming position of the first condenser lens 11. 14 is a second CCD element placed at the imaging position of the second condensing lens 12; 15 is a first CCD element;
a first spatial light modulator whose reflectance is controlled by the charge of the element; 16 a second spatial light modulator whose reflectance is controlled by the charge of a second CCD element; 17 a first CCD; Readout control means for sequentially changing the scanning line readout order of the element 13; 18 is a light source; 19 is a collimator lens that converts the light from the light source 18 into parallel light; 20 is a beam splitter that divides the amplitude of this parallel light; 21 is a beam A half mirror is placed on one optical path split by the splitter 20, and the beam transmitted through this half mirror 21 is the first beam.
22 is a half mirror placed on the other optical path split by the beam splitter 20, and this half mirror 2
The half mirror 21 is placed at a position where the beam transmitted through the second spatial light modulator 16 irradiates the second spatial light modulator 16.
, 22 are arranged at positions where the reflected lights of the beams irradiating the first spatial light modulator 15 and the second spatial light modulator 16 are superimposed. 23 is a photodetector that receives this superimposed light; 24 is a first CCD that is controlled by readout control means 17;
An output that compares the amount of superimposed reflected light from the first spatial light modulation element 15 and the second spatial light modulation element 16 detected by the photodetector 23 every time the scanning line readout order of the element 13 is successively changed. The comparison means 25 is an optical path conversion mirror.

FIG. 2 is a configuration diagram of the spatial light modulation element. 30 is a liquid crystal array layer, 31 is a reflective layer, 32 is a cover glass, and when a voltage is applied to the liquid crystal array layer 30, the transmittance of the liquid crystal changes depending on the voltage value. Therefore, when light enters from the cover glass 32 side, the liquid crystal array layer 30 , reflected by the reflective layer 31 , transmitted through the liquid crystal array layer 30 again, and returned to the incident direction, a reflected light amount distribution proportional to the square of the transmittance of the liquid crystal array layer 30 is given.

The operation of the first embodiment of the present invention configured as described above will be explained based on FIGS. 1 and 3. The first condensing lens 11 and the second condensing lens 1 collect scattered light from an object irradiated with external light such as sunlight and fluorescent lamps.
2, and when the light is received by the first CCD element 13 and the second CCD element 14, outputs as shown in Fig. 3 (a) and (b) are obtained respectively, and the distance to the object is determined. In order to do this, it is necessary to know which part of the output of the second CCD element 14 corresponds to a particular waveform of the output of the tenth CCD element 13 (for example, the hatched part in FIG. 3).

Therefore, the control means 17 reads out the scanning lines corresponding to the hatched portions in FIG.
) line, (K+2)th line, ..., (K+M)th line
) line and apply that charge to the first line to the Mth line of the first spatial light modulator 15. The transmittance of the liquid crystal array layer 30 of the first spatial light modulator 15 is changed by this charge. On the other hand, the charge of the second CCD element 14 is sequentially applied to the first line to the last line of the second spatial light modulation element 16 from the first line to the last line to change the transmittance of the liquid crystal array layer 30. Next, collimator lens 1
The beam parallelized by 9 is sent to a beam splitter 20
, the first and second spatial light modulators 15 and 16 are irradiated via the half mirrors 21 and 22. Since the transmittance of the liquid crystal array layer 30 is spatially modulated by the output waveform of the CCD element, the intensity waveform of the reflected light shows a waveform modulated by the transmittance. Therefore, half mirror 21
, 22, the amount of reflected light from the first spatial light modulator 15 and the second spatial light modulator 16 is detected by the photodetector 23.

Next, the succession control means 17 scans the scanning lines corresponding to the hatched portions in FIG.
+ 1 > line, and similarly the amount of reflected light from the first spatial light modulator 15 and the second spatial light modulator 16 is detected by the photodetector 23.

Thereafter, in the same way, the writing line on the first spatial light modulator 15 is laterally shifted and the charge of the scanning line corresponding to the hatched part in FIG.
Detected by.

In this way, the output of the first CCD element 13 is sequentially recorded by the control means 17 by sequentially shifting the writing line on the first spatial light modulation element 15 so as to record the scanning line corresponding to the hatched part in FIG. , by superimposing the output of the second CCD element 14 with the reflected light from the recorded second spatial light modulation element 16, the hatched part and the part of the output of the first CCD element 13 in FIG. Optical correlation processing of the outputs of the two CCD elements 14 can be performed. That is, in the process of lateral shifting of the hatching section, the location where the amount of superimposed reflected light takes the maximum value becomes the output of the second CCD element corresponding to the hatching section of the output of the first CCD element 13.

As a result, the beam detection point on the first CCD element 13 and the beam detection point on the second CCD element 14 corresponding to the point O on the object, that is, the left and right corresponding points, are determined, and the equation (1)
~(3) can be used to find the distance to the object, and this can be used to perform three-dimensional spatial recognition.

In the embodiments described above, liquid crystals were used as the spatial light modulators 15 and 16, but for example, electro-optic crystals such as BSO crystals may be used and the transmittance or reflectance thereof may be controlled by the charge of the CCD element.

Effects of the Invention The visual device for a robot according to the present invention has a spatial light modulation element and a second CCD element which are recorded by sequentially changing the scanning line readout order of the captured image of the first CCD element by the readout control means. By superimposing the reflected light from the spatial modulation element written with and detecting the amount of light, cross-correlation processing of the output signals of the first and second CCD elements can be sequentially optically performed.
It is possible to provide a high-speed and low power consumption robot visual device.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a visual device for a robot according to a first embodiment of the present invention, FIG. 2 is a configuration diagram of a spatial light modulation element used in the device, FIG. 3 is an explanatory diagram of the operation of the device, and FIG. The figure is a block diagram of a conventional device, and FIG. 5 is an explanatory diagram of the operation of the conventional device. DESCRIPTION OF SYMBOLS 11... 1st condensing lens, 12... 2nd condensing lens, 13... 1st CCD element, 14... 2nd CCD element, 15... 1st space Light modulation element, 16.
. . . second spatial light modulation element, 17 . . . readout control means,
18... Light source, 20... Beam splitter, 21.
・・Half mirror 122・・Half mirror 123・・
- Photodetector, 24... Output comparison means, 25... Optical path conversion mirror, 30... Liquid crystal array layer, 31... Reflective layer. Name of agent: Patent attorney Shigetaka Awano and one other person

Claims (1)

[Claims] A pair of left and right condensing lenses spaced apart by a certain distance, and first and second CCs disposed at the imaging positions of the pair of condensing lenses.
a D element, a readout control means for making the scanning line readout order of the first CCD element variable, and the first and second CC
a pair of spatial light modulators each having a reflectance controlled by the charge of the D element; a light source; light from the light source is split and irradiated onto the pair of spatial light modulators; light reflected from the spatial light modulator; 1. A visual device for a robot, comprising: an optical system that superimposes the superimposed light; and a light detection means that detects the amount of the superimposed light.