JPH01216205A - Position measuring instrument for body in motion - Google Patents

Abstract

PURPOSE:To detect the position of the body in motion with high accuracy by projecting the light from a projection device on the position measuring instrument for the body in motion and finding the direction of view from the projection device when slit light is incident on a photosensor fitted on the body in motion. CONSTITUTION:The slit light (l) projected by the projector 3 is reflected by a mirror 41, scanned horizontally by the rotation of a shaft 42, and projected on the entire surface within the position measurement range of the body 1 in motion. A 1st photosensor 2 outputs its output signal to a processing part 5 through a signal line 6 only when there is the slit light (l) by the horizontal scanning of a scanning device 4. A 2nd photosensor 8 also outputs its signal to the processing part 5 through an output signal line 9 only when there is the slit light (l) by the horizontal scanning of the device 4. The device makes one turn in a constant direction to represent the peak values P2 and P1 of the sensors 2 and 8 as a time difference t1. The processing part 5 finds the angle theta=1/2Xt1Xw between the sensors 2 and 8 which is viewed from a scanning axis X from the time difference t1 and the angular speed (w) of the shaft 42 of the device 4. Then the position of the body 1 in motion is detected.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for determining the specified position of a moving object such as a robot.
The present invention relates to a device for measuring the position of a moving object in a non-contact manner.

[Prior art]

Conventionally, this type of technology has been published in Sensor Utilization Case Studies Collection Information Research Institute Co., Ltd., “Position Analysis of Objects Moving in Three-Dimensional Space J P2.
There was one disclosed in S5 361.

FIG. 5 is a diagram showing a schematic configuration (-dimension only) of this conventional position measuring device. As shown in the figure, this position measuring device includes a point light source 72 fixed at a predetermined position on a moving object 71 such as a robot, a projection lens 73, a detector 4 for detecting the one-dimensional position of the spot, and a processing device 75. .

In the position measuring device having the above configuration, first, light from the point light source 72 is projected by the projection lens 73 onto the detector 4 for detecting the spot position. The detector 4 outputs the position of the spot projected onto the projection plane. Then, from the position of this spot and the position of the detector 4, the angle of the point light source 72 as seen from the detector 4,
In other words, its one-dimensional position can be known.

[Problem to be solved by the invention]

However, in the position measuring device having the above configuration, the movement of the spot projected onto the detector 4 is only several tenths of the movement of the point light source 72, so there is a problem that high accuracy is required of the projection lens 73 and the detector 4. there were.

The present invention has been made in view of the above points, and an object of the present invention is to provide a position measuring device for a moving object that can detect the position of a moving object with high precision without requiring a high-precision day shifter or a projection lens. .

[Means to solve the problem]

In order to solve the above problems, the present invention provides a light projector 3 that projects slit light r from a fixed position, as shown in FIG.
and a scanning device 4 for scanning the slit light, and a light sensor 2 mounted on the moving object 1.
and the optical sensor 8 attached at a fixed position in the slit light ff1(7) irradiation range? The processing unit 5 performs processing based on the time difference between the output peak value of the optical sensor 8 and the output peak value of the optical sensor 2 and the scanning angular velocity of the scanning device 4 to determine the position of the optical sensor 2 as seen from the light projector. It was configured to ask for.

Also, as shown in Figure 2, slit light! In addition to adding an optical sensor 10 attached to a fixed position in the irradiation range, the scanning device 4 can scan at a stable angular velocity,
The processing unit 5 is configured to perform processing based on the time difference between the output peak values of the optical sensor 2, the optical sensor 8, and the optical sensor 10 to determine the position of the optical sensor 2 as seen from the light projector.

[Effect]

By configuring the position measuring device for a moving object as described above, it is possible to directly detect light based on the time difference between the output peak values of the optical sensor 2 and the optical sensor 8, or between the optical sensor 2, the optical sensor 8, and the optical sensor 10. The position of the optical sensor 2 viewed from the light projector of the sensor 2 can be determined with high accuracy. Therefore, there is no need for a day shifter or a projection lens for detecting the spot position with high precision as in the conventional method.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a diagram showing a schematic configuration of a position measuring device according to a first embodiment of the present invention. In the figure, 1 is a moving object such as a robot, 2 is a first sensor attached to a predetermined position of the moving object 1 (for example, at the tip of the arm of the robot), and 3 is a moving object such as a robot.
is a vertically long slit of light! 4 is the slit light from the projector 3! 5 is a processing unit that processes output signals from the first optical sensor 2 and the second optical sensor 8.

The scanning device 4 has a shaft 4 that rotates in one direction as shown by arrow A.
The slit light is equipped with a mirror 41 attached to 2 and is projected from the projector 3! is reflected by the mirror 41,
The rotation of the shaft 42 allows horizontal scanning, and the entire area of the position measurement range of the moving object 1 is irradiated. As a result, the first optical sensor 2 detects the slit light by the horizontal scanning of the scanning device 4! An output signal is output to the processing section 5 through the signal line 6 only when there is a signal. Further, the second optical sensor 8 also outputs an output to the processing unit 5 through the output signal line 9 only when the slit light P is detected by the horizontal scanning of the traveling device 4.

FIG. 3 is a diagram showing the received light intensity of the first optical sensor 2 and the second optical sensor 8. In FIG. As shown in the figure, by rotating the scanning device 4 in a constant direction at a specified angular velocity, the peak values P1*Pt of the first optical sensor 2 and the second optical sensor 8 are
is expressed as a time difference tx (seconds). The processing unit 5 calculates the time difference t1 between these two peak values P* and P+ and the axis 42 of the scanning device 4.
From the angular velocity ω (degrees/second), the scanning axis
The angular difference θ (degrees) between the first optical sensor 2 and the second optical sensor 8 when viewed from the center is determined.

θ-1/2xt1xω Thereby, the position of the moving object 1 is measured.

FIG. 2 is a diagram showing a schematic configuration of a position measuring device according to a second embodiment of the present invention. In this embodiment, a third optical sensor 10 is added to the position measuring device shown in FIG. The output of this third optical sensor 10 is output to the processing section 5 through a signal line 11. In this embodiment, the speed of the scanning device 4 can be determined by adding the third optical sensor 10, so that the scanning device 4 only needs to rotate in a constant direction as shown by arrow B at a stable angular velocity.

FIG. 4 is a diagram showing the received light intensity of the first optical sensor 2, the second optical sensor 8, and the third optical sensor 10. As shown in the figure, by rotating the scanning device 4 in a constant direction at a stable angular velocity, the peak values P+, Pg, and Pa of the first optical sensor 2, the second optical sensor 8, and the third optical sensor 10 are increased. It is expressed as a time difference t*, ts (seconds). The processing unit 5 calculates the time difference t*, ts between these three peak values and the angular difference θ' (degrees) between the second optical sensor 8 and the third optical sensor 10 as seen from the scanning axis X using the following formula. The angular difference θ (degrees) between the first optical sensor 2 and the second optical sensor 8 is output.

θ=1, xθ'/(t, +tm) Thus, the position of the moving object 1 is measured.

Above 1st. In either of the second embodiments, the position of a moving object can be measured with high accuracy without using the highly accurate spot position detector 4 or projection lens 73 as shown in FIG.

In addition, the projected light is a long slit light up and down! Therefore, even if the moving object moves in the vertical direction, position measurement is not affected.

In addition, in the above embodiment, the light projecting device is a slit light! Although the structure is composed of a light projector 3 that projects light and a scanning device 4 that scans the slit light 2 in the horizontal direction, the projector is not limited to this configuration. It may be incorporated into a device, and in short, any light projecting device that emits light while scanning the irradiation range with a vertically long slit light may be sufficient.

Further, in the above embodiment, when one optical sensor (second optical sensor 8) is provided as an optical sensor attached to a fixed position in the irradiation range of the slit light, or two optical sensors (second optical sensor 8 and a third optical sensor 10), but the present invention is not limited to this, and in short, the structure is such that one or more optical sensors are provided at a fixed position in the irradiation range of the slit light. If so, the number of optical sensors is not particularly limited.

〔Effect of the invention〕

As explained above, according to the present invention, the following excellent effects can be obtained.

■ A light projector that scans and emits a slit light to measure the position of a moving object, an optical sensor attached to the moving object, and the direction seen from the projector when the slit light enters the optical sensor. Since the configuration is equipped with a means for determining the spot position, indirect position measurement is not performed on a small day shifter as in the past, but the position is measured more directly. The position of a moving object can be detected with high precision without the need for a precision day shifter or projection lens.

■Also, since a vertically long slit light beam is used for the projected light, even if the moving object moves vertically, the measurement will not be affected.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a schematic configuration of a position measuring device according to a first embodiment of the present invention, FIG. 2 is a diagram showing a schematic configuration of a position measuring device according to a second embodiment of the present invention, and FIG. A diagram showing the received light intensity of the first optical sensor and the second optical sensor, FIG. 4 is a diagram showing the received light intensity of the first optical sensor, the second optical sensor, and the third optical sensor, and FIG. 1 is a diagram showing a schematic configuration of this conventional position measuring device. In the figure, 1... moving object, 2... first optical sensor, 3... floodlight, 4... scanning device, 5...
Processing unit, 6, 7... signal line, 8... second optical sensor, 9... signal line, 10... third optical sensor, 11... signal line .

Claims (1)

[Claims] A light projection device that scans and emits slit light from a fixed position, and a light sensor that is attached to a specified position of a moving object to be measured and detects that the slit light is irradiated to that position. , one or more optical sensors attached to a fixed position in the irradiation range of the slit light to detect that the slit light is irradiated to that position, and an output signal of the optical sensor attached to the moving object and fixed. 1. An apparatus for measuring the position of a moving object, comprising means for processing an output signal of an optical sensor attached to the moving object and determining a direction of the optical sensor attached to the moving object as seen from a light projection device.