JPS59212702A - Position detector - Google Patents

Abstract

PURPOSE:To detect the position of an object to be detected with an excellent precision even on a specific condition by arranging two photoelectric transducers at an interval one-dimensionally to detect the position with a slight change of the detection precision even if the size of the object to be detected is changed. CONSTITUTION:The image of an object 15 to be detected which is illuminated with an illuminating device 14 is formed onto two photoelectric transducers 19a and 19b, which are arranged at an interval one-dimensionally, by an image forming lens 16. The detection signal of brightness of the image is inputted to a controller 17, and the image is moved in the arrangement direction of photoelectric transducers 19a and 19b by a scanning signal from the output of the controller 17. On condition that an interval (a) satisfies a<2d and a/2+d<D< a+2d, the position derection precision is improved. Since two photoelectric transducers are arranged at an interval one-dimensionally, the position of the object to be detected is detected with a slight change of detection precision even if the size of the object is changed. On a specific condition, the position of the object to be detected is detected with an excellent detection precision.

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.

Further, as one method of position detection using a simplified processing system, a scanning signal is outputted by the drive circuit 12, and the galvanometer 6 is driven. An image of the object 2 to be detected, which is imaged by the imaging lens 3 on two adjacently arranged photoelectric converters 4a and 4b, moves in the direction in which the photoelectric converters 4a and 4b are arranged.

The image brightness detection signals A and B outputted from the photoelectric converters 4a and 4b are input to an arithmetic circuit 7, and IA-Bl
is output. The photoelectric converter 4a.

4b in the arrangement direction is d, and the length in the scanning direction of the image of the detected object 2 is D. When it reaches the top, it is compared with E, which was previously set to a certain value so that E > O, and it becomes 1A-Bl>E, and the gate circuit 8
More signals are output.

Next, the image of the detected object 2 is transmitted to the photoelectric converter 4a.
, ab, it is compared with F, which has been set in advance to a certain value such as FzO, and IA-Bl<F is obtained, and a signal is output from the comparison circuit 9.

By the signal outputs of the gate circuit 8 and the comparison circuit 9,
The AND circuit 10 outputs a sampling signal to a sampling circuit 11, and the sampling circuit 11 reads the scanning signal of the drive circuit 12 at that time and outputs a position signal. In FIG. 2, when the image passes between the photoelectric converters 4a and 4b, the detection signal AiJ is inversely proportional to the value of D, and the detection accuracy A11 is inversely proportional to the slope of the detection signal. Therefore, there is a problem in that the position detection accuracy varies greatly depending on the thickness of the detected object.

OBJECT OF THE INVENTION The present invention solves the above-mentioned problems of the conventional technology.It is an object of the present invention to solve the above-mentioned problems of the conventional technology, and to make it possible to minimize the change in detection accuracy even when the size of the target object changes, without sacrificing the feature of using a simplified processing system. It is an object of the present invention to provide a position detection device that performs position detection under certain conditions.

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 one-dimensional two-dimensional device that is arranged on an imaging plane and detects the brightness of the image. a detection device comprising photoelectric converters arranged at intervals; a scanning device configured to move the relative position of an image and the photoelectric converters in the direction in which the photoelectric converters are arranged within an imaging plane; It is comprised of a determining means that determines the position of the object to be detected based on the detection signal and the scanning device, and is configured so that the position of the object to be detected can be determined even if the size of the object to be detected changes without impairing the simplification of the process of detecting the position of the object to be detected. Position detection can be performed with slight changes in detection accuracy.

Description of examples An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 4, the object to be detected 16 illuminated by the illumination device 14 is imaged by the imaging lens 16 onto charging converters 19a and 19b arranged one-dimensionally at two intervals. The photoelectric converters 19a and 19b output image brightness detection signals G and H, respectively, and input them to the control device 17. The imaging lens 16 and the photoelectric converter 19a, 1
A galvanometer 18 is arranged as a scanning device in the middle of 9b, and is driven by a scanning signal output from the control device 17 so that the image moves in the direction in which the photoelectric converters 19a and 19b are arranged.

Next, referring to FIG. 5, to explain the determining principle for determining the position of the detected object 15, the photoelectric converters 19a, 1
9b in the arrangement direction is d, and the length in the scanning direction of the image of the detected object 16 is D, and the Ail photoelectric converters 19a, 1
Let d be the length in the arrangement direction of the interval 9b, then d < D
Under the conditions of < 2 d + a and a < D, the difference GH between the detection signals of the photoelectric converters 19a and 19b is calculated, and the image of the detected object 15 is detected by the photoelectric converters 19a and 1.
When it is located in the middle of 9b, G-H=O1, and near it I
G-1(l)0, otherwise G-H:l:O. The slope of the detection signal when the image passes between the photoelectric converters 19a and 19b is d+la+d-Dl
is inversely proportional to the value of Fig. 7a is a graph showing the relationship between the supplementary angle of the inclination angle of the detection signal and the image size in the conventional example, and Fig. 7b is a graph showing the relationship between the supplementary angle of the inclination angle of the detection signal and the image size in the embodiment. This is a graph that does not show the relationship between Comparing FIG. 7a and FIG. 7b, it can be seen that, compared to the conventional example, in the embodiment, the influence of changes in position detection accuracy in all ranges due to changes in the size of the object to be detected is slight.

Dimension a..., 2d or two 10d < D < a +2
d, and 2d≦a and a (D (a +2 d
It can be seen that under a specific condition such as the case of , the position detection accuracy of the implementation example j is better than that of the conventional VC.

As mentioned above, even if the size of the object to be detected changes, the position can be detected with only a slight change in detection accuracy, and under the specific conditions mentioned above, the position detection accuracy is improved compared to the conventional method. This is the Xrth thing.

When -Vll of the configuration of the control device 17 is shown in FIG.
It is composed of a D circuit 23, a sampling circuit 24, and a drive circuit 25. The detection signals G and I (of the photoelectric converters 19a and 19b are calculated by the calculation circuit 2o and become IQ-H.
l is output. The gate circuit 21 and the comparison circuit 22 are connected to the arithmetic circuit 20, and the gate circuit 2
1 outputs an output signal when the input value IG-Hl becomes a certain value or more, and the next value becomes 2. It outputs an output signal when the value exceeds that level. The outputs of the gate circuit 21 and the comparison circuit 22 are connected to the AND circuit 23,
Four sampling signals are applied to the sampling circuit 24 connected to the drive circuit 25 that outputs the scanning signal. The sampling circuit 24 reads the scanning signal of the driving circuit 25 using a sampling signal and outputs a position signal.

It should be noted that the operation of the position detection device of this embodiment configured as described in section 2 is the same as that of the conventional example described above, and will therefore be omitted.

As described above, according to this embodiment, by arranging two photoelectric converters one-dimensionally at intervals, even if the size of the object to be detected changes, the change in detection accuracy is slight. Under certain conditions, the position of the object to be detected can be detected with higher detection accuracy than conventional methods.

Effects of the Invention The present invention enables position detection with slight changes in detection accuracy even if the size of the object to be detected changes by arranging two photoelectric converters one-dimensionally at intervals. It is possible to realize a position detection device that can detect the position of an object to be detected with higher detection accuracy than before under specific conditions.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of a position detection device as a conventional example;
The figure is a principle diagram showing the decision principle of the conventional example, Figure 3C'',v
Y=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, FIG. 5 is a principle diagram showing the determination principle of the present invention, and FIG. , a block diagram of a control device as an embodiment of the present invention, No. 71 Town Q shows the relationship between the supplementary angle of the inclination angle of the detection signal of the position detection device as a conventional example and the size of the image of the detected object. Characteristic diagram No. 711 shows the detection signal of the position detection device as an embodiment of the present invention. stomach,. Let's meet. □Y is the characteristic diagram shown. 1.14...Illuminating device, 2, 15... Detected object, 3, 16--Imaging lens, 4a, 4b, 19a. 19b... Photoelectric converter, 5, 17... Control device, 6.18 - Force vanometer, 7, 20...
・Arithmetic circuit, 8, 21...Gate circuit, 9, 22...
・Comparison circuit, 10.23・ANDl! l! circuit, 1
1.24--Sampling circuit, 12.25--Drive circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person1
Figure 2 A side Figure 3 Detection I shrine (Figure 156 Building Boima Figure 7 α

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 an illumination device that is arranged on an imaging plane and arranged at two intervals in one dimension to detect the brightness of the image. a detection device comprising a photoelectric converter, a scanning device that moves the relative position of an image and the photoelectric converter in the arrangement direction of the photoelectric converters within an imaging plane, and a detection signal of the outpost detection device and the scanning device. and determining means for determining the position of the detected object.