JPH0452881B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a position detection device for a traveling unit, etc., which detects the direction from a reference point to a measurement point while rotating light.

Generally, when a traveling unit is moving on a defined track, it is easy to detect its position with a reversible odometer, etc.
If the traveling unit moves in an arbitrary direction, it becomes difficult to detect its position, such as its direction.

Conventionally, in order to know the direction of a trackless traveling unit moving in any direction, for example, an optical sensor was used as an angle sensor, a light emitting device was mounted on the traveling unit, and multiple units were placed on a straight line as a reference. A method has been considered in which the direction is detected based on the presence or absence of light by arranging several light-receiving elements, but this method requires a very large number of light-receiving elements, and the angular resolution depends on the number of light-receiving elements. There are disadvantages such as the fact that the error is large due to the influence of

The present invention has been made based on this background, and an object of the present invention is to provide a position detection device that can improve the direction detection accuracy, minimize the number of light receptions, and increase the detection speed and expand the detection range. The purpose is In order to achieve such an object, the present invention provides a light emitting lighthouse that can be rotated at high speed on the child unit, and a light receiver that can be rotated at low speed on the base unit, so that the rotation angle is smaller than that when the light emitting and receiving parts are directly facing each other. It is configured to detect direction.

Hereinafter, one embodiment of the present invention will be described based on the drawings. The position detection device includes a base unit 1 located on a reference point, and a slave unit (trackless traveling) that is moved at a position separated from the base unit 1. unit, etc.) 2 as shown in FIGS. 1 and 2.

The base unit 1 has a turntable 4 rotatably provided on a base 3, and rotates the turntable 4 between the base 3 and the turntable 4 at a low speed, for example, at an angular velocity of about 2.5°/second. A rotary drive mechanism consisting of a drive motor 5, a worm 6, a wheel 7, etc., a rotary encoder 8 for detecting the rotation angle of the turntable 4 with a resolution of, for example, 0.01°, and a rotary encoder 8 for detecting the rotation angle of the turntable 4 at a resolution of 360°. A limit switch 9 is provided on the turntable 4 to detect the angle of rotation as less than 270 degrees by comparing it with the output signal of the rotary encoder 8. A vertical sensor 10 used to set the output signal as a reference angle (for example, when the rotating surface of the turntable 4 is vertical, one point is set as 0°), and an azimuth that detects the azimuth to the slave unit 2. A light receiver 11 constituting a part of the sensor is provided respectively. And receiver 1
1 is set on a reference point, that is, on the rotation center line of the turntable 4.

On the other hand, the slave unit 2 is provided with a light emitter 13 that generates a He-Ne laser beam or the like to constitute an orientation sensor together with the light receiver 11 of the base unit 1 on a base 12 such as a trackless traveling unit. , a light emitting lighthouse 1 in which the light emitter 13 has a laser beam generation source such as a laser diode built into the base 12 or the like, and a through hole for guiding the laser beam from the generation source, and is rotatable.
4, and a top mirror 15 which is attached to the top of the light emitting lighthouse 14 and rotates and radiates the laser beam L parallel to the rotating surface.The light emitting lighthouse 14 is also mounted on the base 12, for example.
A high-speed rotation mechanism including a drive motor 15, a belt 16, pulleys 17 and 18, etc. for high-speed rotation of about 3000 rpm is provided. And handset 2
The optical center point of the light emitter 13 in is set on the rotation center line of the light emitting lighthouse 14. Further, the rotation axis of the light emitting lighthouse 14 and the rotation axis of the light receiver 11 are parallel to each other, and both rotation surfaces are set to be located on the same plane.

Here, to give a supplementary explanation about the light receiver 11, its angular resolution is set to, for example, 0.01°, like the rotary encoder 8, by using a collimator etc., but the reason is that the distance is 3 m.
This is because we want to keep the position detection error (runout) of the handset 2 at 1 mm or less, for example, so runout=3000×0.01/360×1/2π=3000×0.0001745〓0
.52. Such a light receiver 11 is not limited to a collimator, and for example, a high-performance photoelectric conversion element or a one-dimensional semiconductor position detector manufactured by Hamamatsu Television Co., Ltd. can be applied. The position of the optical spot is output as a continuous electrical signal, and the photocurrent is divided according to the distance between the electrodes at both ends of the element and the optical spot, so that the position of the spot can be detected over a range of, for example, 34 mm. become.

On the other hand, when a laser beam is used, its spread is small and the light can reach long distances with little attenuation. Since the outer surface is a non-linear state such as a cylindrical surface, the same plane of the rotating surface of the light emitter 13 may not intersect with the optical center of the light receiver 11. Therefore, by making the top mirror 15 convex only in one axis direction, or by interposing an optical lens having a concave surface only in one axis near the top mirror 15, the laser beam is directed in a direction perpendicular to the rotating surface of the light emitting lighthouse 14. This can be achieved by giving a deflection and tilting the laser beam downward within the range of the deflection angle.

Therefore, when the base unit 1 and the slave unit 2 are each in an operating state, and the light receiver 11 of the base unit 1 is rotated at a low speed or oscillated at a low speed, and the light emitting lighthouse 14 is rotated at a high speed of about 3000 rpm, the laser beam is emitted every second. 50
The light receiver 11 is irradiated at intervals of about 100 times. At this time, the light receiver 11 on the turntable 4
The laser beam is detected only at the moment when the laser beam directly faces the top mirror 15, and by measuring the rotation angle of the turntable 4 at the time of this detection with the rotary encoder 8, the direction of the slave unit 2 can be determined from the base unit 1.
can be detected over the entire rotation range. In this case, if the angular resolution of the rotary encoder 8 is required to be 0.01°, an encoder having a performance of, for example, 16 to 20 bits is used.

As described above, according to the present invention, the following effects are achieved.

A light emitting lighthouse is mounted on the child unit, and it outputs a light beam that rotates at high speed, so the child unit can control the parent unit.
Position detection can be performed at any position in 360 degrees, regardless of direction.

By rotating both the light emitting lighthouse and the light receiver at different rotation speeds, forming the moment when the light emitting lighthouse and the light receiver face each other directly, and detecting the direction at this moment, the limited range of the light spot can be detected. The direction detection accuracy can be improved.

By rotating the light emitter and the light emitter, respectively, it is possible to detect the orientation when the slave unit and the base unit are present within the rotation range of these units, and it is possible to expand the orientation detection range.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, with FIG. 1 being a perspective view of a master unit, and FIG. 2 being a perspective view of a slave unit. 1... Master unit, 2... Slave unit, 4... Turntable, 5... Drive motor, 8... Rotary encoder, 10... Vertical sensor, 11... Light receiver, 1
2...Base, 13...Light emitter, 14...Light emitting lighthouse, 15...Top mirror, 16...Driving motor.

Claims (1)

[Claims] 1. A light-emitting lighthouse that continuously rotates at high speed around a rotating axis perpendicular to the running surface of the slave unit, which is moved at a position apart from the base unit on a reference point, is provided, and the base unit is provided with a light-emitting light that It is equipped with a light receiver that rotates at a relatively low speed around a rotation axis that is parallel to the lighthouse's rotation axis, and that calculates the direction of the light source by detecting the angle of the light receiving direction when directly facing the light receiver. Features: Position detection device for traveling units, etc.