JPH0218485B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for scanning a light beam for guiding and controlling a ground moving object such as an automatic guided vehicle.

The present inventor has been conducting research on a method for operating the above-mentioned ground moving objects using light beams for some time, and based on the results, he has published a "Steering signal generation device for moving objects" (Patent Application No. 141306/1983). Kosho 62−
A patent application was filed as Publication No. 59804)).

Since the present invention is a further improvement of the invention of this application, in order to better understand the present invention, the invention of the application will be summarized before explaining the present invention.

That is, FIGS. 1 to 4 are principle diagrams for explaining the guiding means for a ground moving object that is common to the previous application and the present application. In the figure, a laser beam generator 3 is provided at a fixed position above a route 2 along which a ground vehicle 1 travels. This laser beam generator 3 is connected to a route (for example, a road)
A laser beam having sharp directivity is scanned in a direction along a route along which a ground moving object (for example, an automatic guided vehicle) on the surface of No. 2 is to move. That is, as shown in FIG. 3, the laser beam generator sequentially scans the laser beam LB in the direction along the route on the road 2, from the direction in which the ground mobile object 1 is traveling to the direction in which it should travel. do.

On the other hand, a detection means 4 is provided on the ground moving body 1 to detect the laser beam LB. This detection means 4 detects the laser beam LB, and based on this detection output, the ground moving object 1 detects the laser beam LB.
Generates the steering signals necessary for the LB to move along the scanned path. A steering device included in the ground moving body 1 is controlled based on this steering signal, and thereby the ground moving body 1 moves on the path scanned by the laser beam LB.

As shown in FIG.
Detect LB. FIG. 4 shows a block diagram for explaining this detection means. That is, this detection means includes, for example, two detectors 41 and 42 arranged in a direction intersecting the route. For example, the detector 41 is provided on the right side of the ground vehicle 1, and the detector 42 is provided on the left side. The detection outputs of these detectors 41 and 42 are amplified by amplifier circuits 51 and 52 and given to a discrimination circuit 6 as discrimination means. The discrimination circuit 6 includes an amplifier circuit 51,
Based on the detection outputs of the detectors 41 and 42 amplified at 52, a signal indicating whether the ground mobile object 1 should be steered to the left or right is generated. That is, for example, the right detector 4
If the detector 42 on the left side detects the laser beam LB, it will generate a signal to steer to the right, and if the left detector 42 detects the laser beam LB, it will generate a signal to steer to the left. Furthermore, if it is determined that the laser beam LB is detected at the boundary between the detectors 41 and 42, no steering signal is generated.

Therefore, the output signal of this discrimination circuit 6 is given to the steering device 11 included in the ground moving body 1.
The steering device 11 steers the ground vehicle 1 to the left or to the right based on the discrimination output of the discrimination circuit 6.

In other words, the conventional technology uses a laser beam generator to scan a laser beam with sharp directivity in the direction along the route of the moving body from an arbitrary fixed position near the route of the moving body on the ground. The detection means provided on the mobile body converts the signal into a steering signal necessary for moving on the route, and causes the ground mobile body to steer and travel. However, as a conventional laser beam scanning means, the fifth
As shown in the figure, since the rotation axis of the reflecting mirror 32 is on the extension line of the laser beam LB, the laser beam reflected by the reflecting mirror is
If it were to constantly rotate between B and C in Figure A without stopping at points B and C, it would be between B'C' on the ground, and in terms of time, it would be in a state like B in Figure A.

This means that the reflected laser beam is
Since the scanning is continuous in time, it is difficult to give speed commands etc. to the ground moving body by scanning with this laser beam.

Furthermore, since the laser beam LB is completely blocked by the reflecting mirror 32, only one scanning line can be used with one laser oscillator, making it difficult to use the laser beam effectively. It is.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a laser beam scanning method in which a laser beam LB can give not only a route but also a speed command to a ground moving body. It is an object.

Still another object of the present invention is to enable a laser beam to pass through a reflecting mirror and to utilize the passing laser beam effectively.

Embodiments of the present invention will be illustrated and described below.

FIGS. 6A and 6B are diagrams for explaining a laser beam scanning method according to an embodiment of the present invention.

In FIG. 6A, the reflecting mirror 32' is installed so that its axis of rotation is separated from the laser beam LB by a distance d (however, if the width of the reflecting mirror is l, then l/2>d), The rotation axis 33' is perpendicular to the laser beam LB and parallel to the ground surface. Therefore, if the reflector now rotates as shown by the arrow, the reflector will rotate as shown by the arrow.
If the mirror is between CBs, the reflected laser beam scans the ground surface between B″C″, but if the mirror is removed from between CBs, the laser beam LB passes through the mirror and continues forward. As a result, the laser beam ends up scanning the ground surface intermittently as shown in Figure B.

That is, as shown in FIG. 6B, the laser beam to be scanned is scanned in the form of pulses such as A ₁ , A ₂ , A ₃ . . . . Therefore, by setting the rotation speed of the reflecting mirror separately, for example, by inputting it into a control circuit of a motor that rotates the reflecting mirror 32 according to a command from the CPU 1 in the central control room, the reflecting mirror 32 is precisely controlled, resulting in a pulsed laser beam A. ₁ , A ₂ , and A ₃ per unit time can be made to correspond to the speed command to the ground moving object.

For example, when the number of pulses per unit time is 100, a speed command of 10 Km/S is given, and when the number of pulses per unit time is 300, a speed command of 30 Km/S is given.

However, since a ground moving object generally travels on a route at a speed of VKm/S, the number of pulses received by a detector of the ground moving object is also related to said speed. Therefore, the ground moving body is provided with a speed command detection circuit having a block diagram of an electric circuit as shown in FIG.

That is, the detection output of the laser beam detector 4 is counted by a counter, and this counted number N and the own speed V of the ground moving object are input to the CPU 2, and based on the above information, the CPU 2 determines the speed command from the CPU 1. , this output also determines the speed of the ground vehicle. However, if the rotation speed of the reflector 32' is made very large and the time required to receive the number of pulses per unit time scanned by the laser beam of the ground vehicle 1 is negligible, then the ground vehicle 1 will receive the laser beam.
It is considered that the scanning of the LB is almost stopped. Therefore, the influence of the traveling speed of the ground vehicle 1 can be ignored, and therefore the speed detector may be omitted.

In addition, in the present invention, as illustrated in FIG. 6B,
Since the regions B ₁ , B ₂ , B ₃ ... are the regions of the laser beam that has passed through the reflecting mirror 32', the laser beam LB
There is a reflector 3 further forward than the reflector 32' when viewed from
If a different reflecting mirror with a rotational phase different from 2' is installed and the laser beam LB is reflected by this reflecting mirror, more effective laser beam scanning can be achieved compared to the conventional scanning method. Is possible.

FIG. 6C is an explanatory diagram showing the laser beam scanning method, in which a reflecting mirror 32'' is provided in front of the reflecting mirror 32' in the traveling direction of the laser beam LB.
, when the laser beam LB has the ground surface C'' as one end of the scanning section, that is, when the laser beam LB is reflected at the edge of the reflecting mirror 32' (position D in the figure), the reflecting mirror 32' and the laser beam If the angle formed with LB is α, the rotation angle of the reflecting mirror 32' is
When sin ^-1 2d/l>d>0, the laser beam LB passes through the reflecting mirror 32' and travels forward.
2''.

Then, when the rotational phase of the reflecting mirror 32'' is the rotation angle α=sin ^-1 2d/l of the reflecting mirror 32', the reflecting mirror 32'' is rotated so that an arbitrary desired point C'' on the ground surface becomes one end of the scanning section. Determine the rotation position E. On the other hand, reflector 3
The rotating position F of the reflecting mirror 32'' is set so that one end D'' of the scanning section 2' is the other end of the scanning section of the reflecting mirror 32''.
Establish. The reflecting mirror 32'' is rotated between the rotating positions E and F, and the laser beam LB that has passed through the reflecting mirror 32' is reflected to scan the ground surface.

FIG. 6D is an explanatory diagram showing temporal scanning sections on the ground surface, corresponding to the reference numerals shown in FIG. 6B. However, between C″ and D″ is C,
Areas outside the scanning section from B'' to D'' are indicated by B and D, respectively.

According to the same figure, in addition to the repetition frequency per unit time of A ₁ , A ₂ , A ₃ ..., the repetition frequency per unit time of C ₁ , C ₂ , C ₃ ... corresponds to the speed command to the ground mobile object 1. be able to. In other words, the routes can be divided and different speed commands can be given to each route. Although the rotation axis 33'' of the reflecting mirror 32'' is shown as being provided on the optical axis of the laser beam LB, it may be provided apart from the optical axis.

Further, in the embodiment, the route of the ground mobile object is obtained by scanning a laser beam, but the same effect can be obtained even if other light beams such as infrared rays or visible rays are used.

[Brief explanation of drawings]

1 to 4 are principle diagrams for explaining the guiding means for a ground moving body common to the prior art and the present invention. FIG. 5 shows a conventional laser beam scanning method, FIG. 6 shows a laser beam scanning method according to the present invention, and FIG. 7 shows a speed command detector. 1...Ground mobile object, 2...Route, 3...Laser beam generator, 4...Laser beam detector, 3
2, 32″, 32……reflector, 33′, 33″…
...The axis of rotation of the reflector.

Claims (1)

[Scope of Claims] 1. In a method for scanning a light beam of a ground mobile object that receives and detects a light beam and travels while being guided, the object is located at a predetermined distance from a light beam generator and is separated from the light beam generated by the light beam generator. Predetermined interval d
(However, if the width of the reflecting mirror is l, then l/2>d)
A reflecting mirror is provided at a distant position, and the reflecting mirror is rotated based on a command from the separately provided CPU 1, and the ground moving body moves the light beam emitted from the light beam generator. A repetition frequency per unit time of a pulsed light beam scanned in a direction along a path to be carried out and intermittently scanned over a predetermined section of the ground surface by the reflecting mirror is made to correspond to a speed command to the ground moving object. on the other hand,
The light beam detector provided on the ground moving body detects the light beam, converts the detection output into a steering signal necessary for moving along the route, and causes the vehicle to steer the vehicle, counts the detection output, and calculates the count. Input the number and the speed of the ground moving object to CPU2,
A method for scanning a light beam for guidance and control of a ground moving object, characterized in that the speed and route that the ground moving object should take are determined by comparing the two. 2. In a method of scanning a light beam of a ground moving object that receives and detects a light beam and travels while being guided, the object is located a predetermined distance away from a light beam generator and a predetermined distance d from the light beam generated by the light beam generator.
(However, if the width of the reflecting mirror is l, then l/2>d)
A reflecting mirror is provided at a distant position, and the reflecting mirror is rotated based on a command from the separately provided CPU 1, and the ground moving body moves the light beam emitted from the light beam generator. a repetition frequency per unit time of a light beam scanned in a direction along a path to be carried out and intermittently scanned over a predetermined section of the ground surface by the reflecting mirror, while making the repetition frequency per unit time correspond to a speed command to the ground moving body; The light beam detector provided on the ground moving body detects the light beam, converts the detected output into a steering signal necessary for moving along the route, causes the vehicle to steer, and counts the detected output, A means for inputting the count number and the self-speed of the ground moving object into the CPU 2 and determining the speed and route that the ground moving object should take by comparing and judging the two; A method for scanning a light beam for guidance and control of a ground moving object, characterized in that a reflecting mirror is separately provided and the rotation phases of both reflecting mirrors are made different.