JPS59211805A - Position detector - Google Patents

Abstract

PURPOSE:To achieve the detection of a two-dimensional position of an object by twice scannings with a one-dimensional scanner to match the difference in the size of an object by driving a plurality of limiters individually to limit the light receiving surface of a plurality of photoelectric converters arranged two- dimensionally. CONSTITUTION:A detector is arranged on an image formation surface where an image of an object 16 to be detected illuminated with an illuminator 15 is formed with an image formation device 17 and is made up of four photoelectric converters 18a-18d arranged two-dimensionally to detect the brightness of the image. Sixteen limiters 19 limit the light receiving surfaces of the converters 18a-18d and a scanner 21 moves relative positions of the converters 18a-18d one-dimensionally within the image formation surface. The two-dimensional position of the object 16 is determined from a detection signal of the device 18, a limit signal of the device 19 and a scanning signal of the device 21. Thus, the detection of two-dimensional position can be done to match the difference in the size of the object without impairing features by a simplified processing system.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a position detection device for an industrial robot.

Conventional configuration and its problems When working with an industrial robot, if it is difficult to accurately position the target object, a position detection device is used to obtain position information of the target object. It will be done.

Generally, industrial cameras are used as position detection devices, but they require a processing system with advanced calculation functions, which poses many problems in terms of cost. In addition, as a method of position detection using a simplified processing system, the first
2 and 3, the object 2 to be detected illuminated by the illumination 1 is imaged by the lens 3, and four photoelectric converters 4a, 4b, 4c are arranged two-dimensionally. The image is formed on 4d. the imaging lens 3 and the photoelectric converter 4a.

A galvanometer 5 is arranged as a scanning device between 4b, 4c, and 4d, and a scanning signal output from a control device 6 is used to scan the photoelectric converters 4a, 4b, and 4a.

The image is driven to move diagonally in the arrangement direction of each of the 4Cs. First, a scanning signal is output from the drive circuit 7,
The galvanometer 5 is driven, and the photoelectric converter 4a
, 4b, 4c, 4d, the image power ζ of the object 2 is imaged on 4b, 4c, 4d.
It moves obliquely in the arrangement direction of the photoelectric converters 4a, 4b and 4a, 4c. The photoelectric converters 4a, 4b,
Detection signal P+ of 4c and 4d.

P2, Ps, P4 are input to the arithmetic circuit 8a, and 1
(P1+P3) to (P2+P4)l are input to the switching circuit 9. When a switching signal is input from the direction specifying circuit 1o to the switching circuit 9, + ('P1+P3)-Me Sa>
Compared with Sa set to a certain value such that O, 1
(P1+P3)-(P20P4)1>Sa,
A signal is output from the gate circuit 11. Next, the image of the object to be detected 2 is transmitted to the photoelectric converter 4a.

When it comes to the middle of 4C, 4b', and 4d, T a zO
Compared with the Ta meeting set to a certain value such that 1(
P10P3)-(P2+P4)l<Ta, and the comparison circuit 12 outputs a signal. Based on the signal outputs of the gate circuit 11 and the comparison circuit 12, the AND circuit 1S outputs a summing signal to the sampling circuit 14,
The sampling circuit 14 controls the drive circuit 7 at that time.
Read the scanning signal of the light! A position signal in the array direction of the transducers 4a and 4b is output. After that, when the image of the object to be detected 2 comes on the photoelectric converters 4b and 4d, 1
(P1+P3)-(P2+P4) l>Sa, and the signal from the gate circuit 9a disappears. In addition, the input to the arithmetic circuit 8b is l (P1+P2)-(P3-
1-P4)l is input to the switching circuit 9. If the switching signal from the direction specifying circuit 1o is not input to the switching path 9, 1(P1+P2)-(P3+P4)l is output from the switching circuit 9. The sampling circuit 14 outputs a position signal in the arrangement direction of the photoelectric converters 4a, 4c. In this way, the image formed on the four photoelectric converters arranged two-dimensionally is moved diagonally by the scanning device in the arrangement direction of each of the four photoelectric converters, and the four photoelectric converters are Detection signals that perform position detection by arithmetic processing are required to optically change the image magnification when the size of the object to be detected differs, which poses a problem in terms of quick response. Ta.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned problems of the conventional art, without sacrificing the feature of a simplified processing system.
It is an object of the present invention to provide a two-dimensional position detecting device that detects the two-dimensional position of an object by scanning twice with a one-dimensional scanning device in response to the difference in the size of the target object.

Structure of the Invention The present invention includes an illumination device that illuminates an object to be detected, an imaging device that forms an image of the object to be detected, and a two-dimensional A detection device consisting of a plurality of photoelectric converters arranged in an array, a limiting device arranged in a plurality of pieces to limit the light receiving surface of the photoelectric converter, and an image forming system that determines the relative position of an image and the photoelectric converter. Consisting of a scanning device that moves one-dimensionally within a plane, and determining means that determines the two-dimensional position of the detected object based on a detection signal of the detection device, a limiting signal of the limiting device, and a scanning signal of the scanning device. However, without sacrificing the simplification of the process of detecting the position of the detected object,
The one-dimensional scanning device scans twice to immediately respond to the difference in size.
It measures dimensional position detection.

Description of examples An embodiment of the present invention will be described below based on the drawings.

In FIG. 4, four photoelectric converters 18a, 18b, and 18c are arranged two-dimensionally by an imaging lens 17 to detect objects 16 illuminated by an illumination device 15.

The image is formed on 18d. The photoelectric converter 18 a + 1
A limiting device 19 for limiting the dimensions of the light receiving surface is arranged on the light receiving surface of 8b+IBc and 18d, and is driven by a drive signal output from the control device 2°. The limiting device 19 utilizes the electro-optic effect of liquid crystal, and includes 19a,
Consists of 16 liquid crystals of 19b...19p,
The arrangement direction is the photoelectric converters 18&, 18b.

180.18d, and the restriction device 19
b, 19f, 19j, 19n and j 9c, 19(
J plsk, the center line of 19o and the photoelectric converter 18a
.

The center lines of 18c, 18b, and 18d are connected to the restriction device 19.
9, 19f, 19g, 19h and 19=, 1sj.

19, the center line of 191 and the photoelectric converter 18a;

18b and 18C218d are arranged so that their cauldrons are aligned, and each is configured to transmit light when energized and to block light when cut off. A galvanometer 21 is arranged as a scanning device between the imaging lens 17 and the limiting device 19,
The scanning signal output from the limiting device 2o drives the image to move obliquely in the arrangement direction of each of the photoelectric converters 18a, 18b and 18a, 18c, and the image is moved perpendicular to the optical axis of the imaging lens 17. The galvanometer 21 is arranged so that the angle between the plane and the pivot axis of the galvanometer 21 is θ in the clockwise direction in FIG.

Next, referring to FIGS. 6.7 and 8, to explain the principle of determining the position of the object to be detected 16, the shape of each of the arranged limiting devices 19a, 19b...19p is Converters 1sa, 1ab.

If the size of each of 1sc and 1sd is 21 x 211 and the size of the detected object 16 is LXL, then if the size of the detected object is L(2, /, then the limiting devices 19b, 15
jc, 19f, 19g, 19j.

191C, 19n, 19o and 19e, 19f, 19
g.

By energizing 191 to 19h, 1st, 19j, and 19, even if the image moves diagonally in the array direction, 47 sin θ, 4. The image of the object to be detected 16 located in the middle of '/1 cos θ is always captured by the limiting device 19.
b, 19f, 19j, 19n and 19c, 19g, '19
k.

190, also 19e, 1sf, 1eg, 1sh and 19
i, 19j.

19, the brightness of the image of the photoelectric converters 18a, 18b, 18c, 1B, d across the center line of the array interval 191 P3)-(P2+P4)l,l(P1+P2)-(
P3+P'4) 'I is obtained from the detected object 16.
The images of the restriction devices 19b, 19f, 19j,
19n, 19c, 19q'.

When it is located between 19 and 19o, l (P1+'
P3)-(P2+P4)lzo, 19e, 19f, 1
9g, 19h and 19i, 19j, 19, 191
When it is located in the middle of , l (P10P, 2 ) - (P
3+P4) l;O, in the vicinity, 1 (P 1
10P3) (P2 +P4) I > Oz
I (P1+P2)-(P3+P4) I>
O, otherwise 1(P1+P3)-(P2+P4)
l: o, l (P1+P2)-(P3+P4)l becomes 0. Further, the dimensions of the detected object 16 are l<L<31
In this case, the restriction device 19a.

19c, 19e, 19g, 19i, 19k, 19m
, 19o and 19a, 19b, 190, 19d, 191.
19j719k.

191 is energized, and when 2n<L<41, the limiting devices 19a, 19d, 19e, 19h, 19i.

191.19m, 19p and 19a, 19b, 19c
, 19d.

The focus is on the fact that by energizing 19m, 19n, 19o, and 1'9p, the same result as in the case of L<21 described above can be obtained.

An example of the configuration of the control device 20 is shown in FIG.
Dimension designation circuit 22, direction designation circuit 2''3, liquid crystal drive circuit 24, arithmetic circuit 2s'a, 2sb, x switching circuit 2
6, gate circuit 27, comparison circuit 28, AND circuit 29,
It consists of a sampling circuit 30° and a galvano drive circuit 31. A dimension designation circuit from the dimension designation circuit 22,
When the direction specifying signal and the switching signal are output from the direction specifying circuit, the liquid crystal drive circuit 24 limits the drive signal to the limiting devices 19b, 1.9c, 19f, 19g, 19j,
'19k, 19n, 19o and 19e, 1sf,
19h.

19i, 19j, 19, 191 and 19a, 19
c.

19e, 19g, 19i, 19, 19m, 19o.

and 19a, 19b, 19c, 19d, 19i.

191.19, 191 and 19a, 19d, 19
e.

1sh, 1si, 1sl, 1em, 19p and 19a
.

The switching circuit 26 outputs to any one of 19b, 19c, 19d, 19m, 19o, and 19p, and the switching circuit 26
One of the outputs of the arithmetic circuits 25a and 25b is outputted to the gate circuit 27 and the comparison circuit 28. The photoelectric converters 18a, 1'8b.

18G, 18d detection signal P1. P2, P3. P4 is calculated by the calculation circuits 25a and 26b, respectively (P2
+P4)-(P10P3), (P1+P2)-(
P30P4). The gate circuit 27 outputs an output signal from when the input value exceeds a certain value until it falls below a certain value, and the comparator circuit 28 outputs an output signal when the input value reaches the input value mio.

The outputs of the gate circuit 27 and the comparison circuit 28 are the A
The sampling circuit 3 is connected to the ND circuit 29 and connected to the galvano drive circuit 31 that outputs a scanning signal.
Give a sampling signal to o. The sampling circuit 3Q reads the scanning signal of the galvano drive circuit 31 using a sampling signal and outputs a position signal.

Next, the operation of the position detection device of this embodiment configured as described above will be explained below.

When detecting the detected object of L<21, first, a dimension designation signal is sent from the dimension designation circuit 22, and a dimension designation signal is sent from the direction designation circuit 23.
Yop-+ direction designation signal and switching signal are output,
The liquid crystal drive circuit 24 outputs a drive signal to the limiting device 19, and the limiting devices 19b, t9c, 19f, 19
g, 19j, 191c.

19n and 19o are energized to transmit light, and the switching circuit 26 is the photoelectric converter 18a.

18b, 18c, 18d detection signals P1. P2゜P3.
(P2+P4) of the calculation circuit 25a which calculates and outputs P4.
) −(Pl +P3 ), the gate circuit 2
7. Output to the comparison circuit 28. At the same time, a scanning signal is output from the galvano drive circuit 31, the galvanometer 21 is driven, and the photoelectric converters 18a, 18b,
The image of the object to be detected 16 formed on 18c and 1ad is transmitted to the photoelectric converters 18a and 18b and IBa,
It moves at an angle of θ with respect to the arrangement direction of each of 18C. The image of the detected object 16 is the restriction device 19b,
19f.

When reaching 19j and 19n, compare it with Sa, which was previously set to a certain value such that Sa>o, and get (P20P4) - (
P1+P3))Sa, and a signal is output from the gate circuit 27. Next, the image of the detected object 16 is transmitted to the restriction devices 19b and 19f.

19j, 19n, 19c, 19g, 19, when it comes to the middle of 19 degrees, compare it with Ta, which was previously set to a certain value such that Ta; O, and calculate (P2 + P4) - (P1 + P3
) -Ta, and the comparison circuit 28 outputs a signal. Based on the signal outputs of the gate circuit 27 and the comparison circuit 28, the AND circuit 29 outputs a sampling signal to the sampling circuit 30, and the sampling/circuit 3o reads the scanning signal of the galvano drive circuit 31 at that time. p1 Outputs a position signal in the arrangement direction of the photoelectric converters 18a and 18b. After that, the detected object 16
The images are of the restriction devices 19c, 19g, and 19k.

When reaching 19o, compare it with sb previously set to a certain value such that Sb<O, and calculate (P2+P4)-(P1+P
3) (Sb becomes Sb, and the signal from the gate circuit 27 disappears.Next, the scanning signal of the galvano drive circuit 31 becomes 1.
When the cycle ends, the direction specifying signal and switching signal of the direction specifying circuit 23 change, and the limiting device 19e,
19f, 19g, 19h.

19i, 19j, 19, 191 is energized to transmit light, and the switching circuit 26 receives (Pl + P2) - (P3 + P4) of the arithmetic circuit 26b and outputs it to the gate circuit 27 and the comparison circuit 28. do. At the same time, the galvano drive circuit 31 outputs a scanning signal, and from here on, in the same manner as described above, (P1 + P2) - (P
30P4) is the gate circuit 27, the comparison circuit 2
8. Processed by the AND circuit 29, the sampling circuit 30 reads the scanning signal of the galvano drive circuit 31 at that time, and the scanning signal is processed by the photoelectric converter 18. a, 180 position signals in the array direction are output.

Furthermore, since the case of detecting a detected object with l<L<31.21<L'<41 is as described above, the explanation will be omitted.

As described above, according to this embodiment, by individually driving the 16 arrayed control devices and limiting the light receiving surface of the 4 two-dimensionally arrayed photoelectric converters, the size of the target object can be controlled. In response to the difference, the two-dimensional position of an object can be detected by scanning twice with a one-dimensional scanning device without sacrificing the feature of a simplified processing system.

In the embodiment, 16 limiting devices were used, but it goes without saying that similar results can be obtained even if the restricting devices are arranged in a different number. 1. In the case of FIG. 8, the limiting devices 19f, 19Cr 119j, and 19k are not energized, but all of the inner limiting devices may be in a transparent state as shown in FIG.

Effects of the Invention The present invention uses a scanning device to move an image formed on four photoelectric converters arranged in a two-dimensional manner diagonally in the arrangement direction of each photoelectric converter, and a limiting device to control each photoelectric conversion. By limiting the light-receiving surface of the device and processing the detection signals of each photoelectric converter, a simplified processing system can quickly respond to differences in the size of the detected object with two scans of the one-dimensional scanning device. As a result, it is possible to realize an excellent position detection device that can obtain the effect of detecting the two-dimensional position of the detected object.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a position detection device as a conventional example, FIG. 2 is a principle diagram showing the determination principle of the conventional example, FIG. 3 is a configuration diagram of a control device as a conventional example, and FIG. Fig. 5 is a block diagram of a position detection device as an embodiment of the present invention, and Fig. 5 is a block diagram of a restriction device arranged in 16 pieces as an embodiment of the present invention.
Figure 9 is a principle diagram showing the determination principle of the embodiment of the present invention;
The figure is a configuration diagram of a control device as an embodiment of the present invention. 1.16...Lighting device, 2,16...
Object to be detected, 3, 17---Imaging lens, 4a
, 4b, 4c. 4d, 1sa, tab, 1sc, '1sd--Photoelectric converter, 5.21... Galvanometer, 6.20
...Control device, 19...Restriction device. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 ttltrffi Figure 3 □ Figure 5

Claims (1)

[Claims] An illumination device that illuminates an object to be detected, an imaging device that forms an image of the object to be detected, and four photoelectric converters that are arranged two-dimensionally and arranged on an imaging plane to detect the brightness of the image. a detection device, a plurality of limiting devices arranged to limit the light-receiving surface of the photoelectric converter, a scanning device that moves the relative position of the image and the photoelectric converter one-dimensionally within an imaging plane, and the detection device a determining means for determining a two-dimensional position of the detected object based on a detection signal of the limiting device, a limiting signal of the limiting device, and a scanning signal of the scanning device.