JPS59174706A - Position detecting device - Google Patents

Abstract

PURPOSE:To detect the two-dimensional position of a body to be checked in a broad range by a one-dimensional scanning device in a simplified processing system, by changing the shape of the light receiving surface of a photoelectric converter, which is divided into four parts, by using the electro-optical effect of a liquid crystal, and forming a rectangular shape, which is short in the detecting direction. CONSTITUTION:A direction signal (c), a driving signal (a) and a switching signal (f) are outputted from a direction specifying circuit 27. A scanning signal (d) is outputted from a galvano-driving circuit 33. Position signals (e) in the aligning direction of photoelectric converters 18a and 18b are outputted from a sampling circuit 32 as a conventional way. When the direction signal (c) and the driving signal (a) from the direction specifying circuit 27 are changed and the switching signal (f) is not outputted, segments 22d, 22e and 22f in a limiting device 21 are conducted and become a light transmitting state, and 22d, 22e and 22h are cut off and become a light shielded state. The switching circuit 26 outputs an input from an operation circuit 25b. The position signals in the aligning direction of photoelectric converters 18a and 18c are outputted from the sampling circuit 32 by the similar way.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a position detection device for industrial robots and the like.

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 often poses problems in terms of cost. 1. As a method of position detection using a simplified processing system, the first method is
2 and 3, light Φ, which is divided into four parts by the imaging lens 3 from the object 2 to be detected illuminated by the illumination 1, is transmitted onto the converters 4a, 4b, 4C, and 4d. Form an image. AiJ imaging lens 3 and the photoelectric converter 4a,
4b, 4c.

Between 4d and 4d, a Garneau meter 6 is arranged as a scanning device, and a scanning signal outputted from the control device 6 is used to scan diagonally in the direction of arrangement of each of the photoelectric converters 4a, 4b and 4a, 4c. First, the drive circuit 7 outputs a scanning signal, and the galvanometer 6
or the light 1b is cooperated.

The images of the object 2 formed on the converters 4a, 4b, 4C, and 4d are the photoelectric converters 4a, 4b, and 4a.

Move in the direction of the 4C array. Detection signals P1. of Ail photoelectric converters 4a, 4b, '4C, 4d. P2
゜P3. P4 is input to the arithmetic circuit 8a and becomes 1(P1+P
3) −(P2+P4 is input to the switching circuit 9.

When a switching signal is input from the direction specifying circuit 10 to the switching circuit 9, the switching circuit 9
, 1(P1+P3)-(P2+P4)1 is output. The image of the detected object 2 is transmitted to the photoelectric converters 4a and 4c.
When it reaches the top, compare it with Sa, which was previously set to a certain value such that 5a)O, and get 1 (PI + P3) - (P2 + P
4)1. >Sa, and a signal is output from the gate circuit 11. Next, the image of the detected object 2 is transmitted to the photoelectric converters 4a, 4C, and 4b.

When it reaches the middle of 4d, it is compared with Ta, which is set in advance to a certain value such that Ta is O, and 1(P1+P3)-(P
2+P4)1<Ta, and a signal is output from the comparison circuit 12. The gate circuit 11 and the comparison i
In response to the signal output from the circuit 12, the AND circuit 13 outputs a sampling signal to the sampling circuit 14, and the sampling circuit 14 reads the scanning signal of the drive at that time. A position signal in the arrangement direction of 4b is output.

Thereafter, the image of the detected object 2 is transmitted to the photoelectric converter 4b.
, When it comes to 4d, 1(P1+P3)-(P2+P
4) 1) Sa and the signal from the gate circuit 9d disappears. The input to the arithmetic circuit 8b is 1 (P10P
2)-(P30P4)1 is input to the switching circuit 9. If no switching signal is input from the direction specifying circuit 10 to the switching circuit 9, the switching circuit 9 outputs 1(P1+P2)-(P3+P4)1, which is then processed as described above, and the sampling circuit 14 outputs 1(P1+P2)-(P3+P4)1. The positions and words in the arrangement direction of the photoelectric converters 4a and 4c are output.

In this way, the image formed on the 4-split photoelectric converter is moved diagonally in the arrangement direction of each 4-split photoelectric converter by the scanning device, and the detection signals of the 4-split photoelectric converters are each processed by calculation. As a result, the method that performs position detection is effective only when the scanning width can be narrow, and there is a problem that the scanning width cannot be widened.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional problems, and achieves the following without sacrificing the feature of a simplified processing system.
It is an object of the present invention to provide a two-dimensional position detection device that detects the two-dimensional position of a target object over a wide range by scanning twice with the dimensional scanning device.

Structure of the Invention The present invention comprises an illumination device for illuminating an object to be detected, an imaging device for forming an image of the object to be detected, and four devices disposed on an imaging plane to detect the brightness of the image. a detection device comprising a divided photoelectric converter; a limiting device for limiting a light receiving surface of the photoelectric converter; a scanning device for moving the relative position of an image and the photoelectric converter in one dimension within an imaging plane; It is comprised of a determining means that completely determines the two-dimensional position of the object to be detected based on the detection signal of the detection device and the scanning signal of the scanning device, and the one-dimensional By scanning twice with the scanning device, detection is performed over a two-dimensional area over a wide area.

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

In FIG. 4U, a detection object 16 illuminated by an illumination device 15 or a photoelectric converter 1 divided into four parts by an imaging lens 17 is shown.
Images are formed on 8a, 18b, 18c, and 18d. The photoelectric converters 18a, 18b.

A limiting device 21 for limiting the dimensions of the light receiving surface is disposed on the light receiving surface of the 18C518d, and is driven by a drive signal output from the control device 2°.

The limiting device 21 uses the electro-optical effect t51''j of the liquid crystal.
22a, 22b, 22C, 22d
.

It is composed of eight segments of liquid crystal 22e, 22f, 22g, 22h, and 22i, and each segment is configured to transmit light by energizing it, and to block light by blocking each segment. In FIG. 5, the segments 22b, 22e.

By energizing 22h, the optical IH converter 18a
.

18b, 18G, 18d light receiving surface curve +1φ shape is l”l
×12 vertically long rectangular shape, the segment) 22d
.

By energizing 22e and 22f, it becomes a horizontally long rectangular shape. Further, the light-receiving surface dimension 11 is set so that L<2 l , where L is the length of the object to be detected. A galvanometer 23 is disposed as a scanning device between the imaging lens 17 and the limiting device 21, and a scanning signal output from the control device 20 is used to scan the photoelectric converter 18a.
, 18b and 188° 18C, and the angle between the plane perpendicular to the optical axis of the imaging lens 17 and the rocking axis of the galvanometer 23 is a fourth angle. The galvanometer 22 is arranged so as to be oriented clockwise at θ in the figure.

Next, referring to FIG. 5, to explain the determining principle for determining the position of the detected object 16, the photoelectric converters 18a, 1
8b, 18c, and 18d, and utilizes changes in light transmittance due to energization and interruption of the liquid crystal! 21V, the optical beam converter 18a.

By restricting the light receiving surfaces of 18b, 18C, and 18d to a rectangular shape that is short in the detection direction and long in the width direction,
Even if the images move diagonally in the array direction, each 2l 2s
The image of the object to be detected 16 located at the middle white of inθ, 2β2CO5θ is necessarily captured by the photoelectric converter 18a.

18c and 18b, 18d also 1sa, 1sb and 18C
, 18d, and the photoelectric converters 18a, 1
Detection signal P1 of brightness of images 8b, 18G, 18d,
P2. P3. From P4 1 (P1 + P3) - (P20 P4
)1.1 (P1+P2)-(P3+P4)1 is calculated using the image of the detected object 16 or the photoelectric converter 18a.
, 16c and 1sb, 1s, d (is,
1. (P1+P3) -(P2+P4>1z0,18a
, 1 When located between sb, 1sc, and 1sd, 1
(Pl 10P2) - (P3+P4), 1 Ol
.

In the vicinity, 1(P1+P3)-(P2+P4)1>>
The focus is on the point that ○, 1(P1+P2)-(P3+P, 4)1>>O.

An example of the configuration of the control device 24 is shown in FIG.
Arithmetic circuits 25a, 25b, switching circuit 26, direction specifying circuit 27, liquid crystal drive circuit 28, gate circuit 29, comparison circuit 30SAND 31, sajibring circuit 32,
It is composed of a galvano drive circuit 33. Direction specifying circuit 27'': When a reisoting signal is output to the switching circuit 26 and a liquid crystal drive signal is output, and a signal is output from the liquid crystal drive circuit 28 to the resegmenters 22b and 22q, the photoelectric converters 18a, 18b+, 18c .

18d detection signal P1. P2, P'3, and P4 are calculated by the calculation circuit 25a, and are calculated by the switching circuit 2.
6 outputs 1(,P10P3)-(P20P4)1. The switching circuit 26 is connected to the gate circuit 29 and the comparison circuit 3Q, and the gate circuit 2
9, input value 1 (P1+P3) = (P2+P4)
When 1 exceeds a certain value, it outputs an output signal when the next value exceeds a certain value. Outputs an output signal when the following values occur. The outputs of the gate circuit 29 and the comparison circuit 30 are connected to the AND circuit 31, and provide a sampling signal to the sampling circuit 32 connected to the galvano 1 drive circuit 33 which outputs a scanning signal.

The sampling circuit 32 reads the displacement signal of the galvanometer drive circuit 33 using the sampling signal and outputs a position signal. Next, when the switching signal output from the direction specifying circuit 27 disappears, the direction signal and the liquid crystal drive signal change, and the segnon) 22 is output from the liquid crystal drive circuit 28.
d, 22G.

When a signal is output to 22f, the photoelectric transformer 18a
.

18b, 18C218d detection signal P1. P2゜P3.
P4 is calculated by the calculation (b) path 25b, and is calculated by the switching circuit 26 as 1(P1+P2)−(P3+P4
)1 is output. Thereafter, the processing is performed as described above, and a position signal is output from the sampling circuit 32.

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

First, a direction signal, a drive signal,
A switching signal is output, and the segments 22b and 22q of the side/plate device 21 are energized and become in a light transmitting state, and the switching circuit 26 outputs the input from the arithmetic circuit 25a. At this time, when a scanning signal is output from the galvanometer and drive circuit 33, the scanning signal is output from the sampling circuit 32 to the photoelectric converters 18a and 18b.
It is the same as in the conventional example that a position signal in the arrangement direction of is outputted, so a description thereof will be omitted. Next, the direction signal and drive signal from the direction finger/foot circuit 27 change, and the switching signal disappears (when the segment 2 of the restriction device 21
2d, 22e7, and 22f are energized and put into a light transmitting state, and 22b, 22e, and 22h are cut off and put into a light shielding state, and the switching circuit 26 outputs the input from the arithmetic circuit 25b. The sampling circuit 32, the photoelectric converters 18a and 18c
A position signal in the arrangement direction is output.

As described above, according to this embodiment, the 11-chip shape of the light receiving surface of the 4-split photoelectric converter is changed using the electro-optic effect of the liquid crystal to form a short rectangular shape in the detection direction, thereby simplifying the structure. The two-dimensional position of the object to be detected can be detected over a wide range with a one-dimensional scanning device using a processing system.

Effects of the Invention The present invention changes the shape of the light-receiving surface of a 4-split photoelectric converter using the electro-optic effect of liquid crystal to form a short rectangular shape in each detection direction.
With the dimensional scanning device, it is possible to realize an excellent position detection device that can obtain the effect of detecting the two-dimensional position of a detected object over a wide range.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of a position detection device as a conventional example;
3 is a configuration diagram of a control device as a conventional example, FIG. 4 is a configuration diagram of a position detection device as an embodiment of the present invention, and FIG. The figure is a principle diagram showing the decision principle of the present invention, and FIG. 6 is a configuration diagram of a control device as an implementation sequence of the present invention. 1.15...Lighting device, 2,16...
Object to be detected, 3, 17-1 imaging lens, 4a, 4b
, 4c4d, 18a, 18b, 18G, 18d--Photoelectric converter, 5, 23-... Galvanometer, 6, 2
゜...control device, 22a, 22b, 22c, 22
d. 22e, 22f, 22g, 22h, 22i
---One liquid crystal segment. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 4 Figure 5

Claims (1)

[Claims] An illumination device that illuminates the object to be detected, an imaging device that forms an image of the object to be detected, and a photoelectric converter divided into four parts arranged on the imaging plane and that detects the brightness of the image. a detection device that limits 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 a detection signal of the detection device and the scanning device. and determining means for determining the two-dimensional position of the detected object based on the scanning signal.