JPH087259B2 - Position detection device for moving body - Google Patents

Description

The present invention relates to an apparatus for detecting the position of a movable body such as a civil engineering work vehicle such as a dump truck or a bulldozer, a work boat in a bay, or a carrier vehicle in a factory. Regarding

[Conventional technology]

As shown in Japanese Unexamined Patent Publication No. 62-50616, laser light projectors that rotate at two reference points are installed, a laser light receiver is provided at a measurement point, and this laser light receiver is connected to an arithmetic unit. While the laser beam of one reference point is turning by the arithmetic unit, the measurement point of the other reference point and the time difference of the laser beam arrival at the measurement point and the other reference point are obtained respectively, and these time difference and the distance between both reference points There is known a device that detects the position of a measurement point by calculating the coordinates of the measurement point from the above.

[Problems to be Solved by the Invention] With such a position detecting device, a laser projector must be installed at each of two reference points, and two expensive laser projectors are required, so that the entire apparatus becomes expensive. At the same time, properly install the laser projector at the two reference points.
It is necessary to set the distance between the two laser projectors to a predetermined distance, and not only is the installation work of the laser projectors troublesome, but the installation of the moving body cannot be accurately detected if there is an installation error.

Therefore, an object of the present invention is to provide a position detecting device for a moving body, which is capable of detecting the position of the moving body by using one laser projector.

[Means and Actions for Solving Problems]

A first laser beam 18 and a second laser beam 19 which are projected at an angle of θ in a vertical plane are provided at a reference point of the moving area, and the first laser beam 18 has a constant output at all times. The laser light 19 has an output proportional to the rotation angle φ from the reference azimuth, and the laser projector 1 is installed rotatably in the horizontal direction,
The rotation angle φ of the laser projector 1 and the distance R to the laser projector 1 are calculated on the moving body according to the laser receiving section 22 capable of receiving light in all directions and the receiving states of the first and second laser beams 18 and 19, and The laser receiver 3 equipped with a calculation unit 27 for calculating the position based on the rotation angle φ and the distance R is attached,
The position where the position can be detected by receiving the first and second laser beams 18 and 19 projected from one laser projector 1 by the laser receiver 22.

〔Example〕

A laser projector 1 is rotatably installed in a horizontal plane direction at a reference point of a moving area, for example, a reference point of a civil engineering work area, and a laser beam is received by a moving body moving in the moving area, for example, a bulldozer 2 moving in the civil engineering work area. Attach the device 3 and the transmitter / receiver 4, and place it anywhere, for example, the central management office 5
A display panel 6 and a transmitter / receiver 7 are mounted inside, and the laser receiver 3 detects the position of the bulldozer 2 by receiving the laser light from the laser projector 1, and the transmitter / receiver 4 and 7 indicate the position. The work operation command is output to the bulldozer 2 in accordance with the position of the bulldozer 2 displayed on the display panel 6.

The laser projector 1 has a base 10 as shown in FIG.
The laser projector main body 11 is rotatably supported in the horizontal plane direction, and the rotary body 14 connected to the motor 13 is pressed against the inner peripheral surface of the ring body 12 attached to the laser projector main body 11 to drive the motor 13. This allows the laser projector main body 11 to rotate together with the rotating body 14, and
A rotation angle detector 15 is pressure-contacted to the outer peripheral surface of the laser projector. The laser projector main body 11 is provided with first and second laser projectors 16 and 17, and the first laser projector 16 is connected to the first laser beam. The second laser projector emits 18 in a horizontal direction at a constant output.
A second laser beam 19 is projected upward from the horizontal direction with an output proportional to the rotation angle. That is, the second
The output of the laser beam 19 is controlled so as to increase sequentially while rotating 360 degrees in proportion to the rotation angle detected by the rotation angle detector 15.

For example, a semiconductor laser is used for the second laser projecting unit 17, and the drive current of the semiconductor laser is set to the rotation angle detector.
By controlling the rotation angle from 15, it is possible to sequentially increase the projection output of the laser light every 360 ° rotation as shown by the solid line in FIG. The first laser light 19
Output is as shown by the broken line in FIG.

Further, the first laser light 18 and the second laser light 19 are projected at the predetermined angle θ.

As shown in FIG. 4, the laser receiver 3 has a laser receiver 22 attached to a base 21 having four telescopic legs 20. The laser light receiving portion 22 is always vertical, and the laser light receiving portion 22 has a solar cell attached to the outer surface of a cylindrical body so that the position where the laser light is received can be sensed. .

That is, as shown in FIG. 5, a large number of solar cells 23 are attached at equal intervals in the vertical direction, and the solar cell 23a, 23b that has received the first laser light 18 and the second laser light 19 reduces the distance l between them. I can know.

FIG. 6 is a schematic explanatory view of the laser projector and the laser receiver. The first laser projector 16 is controlled by the first drive circuit 24 so that the output is always constant, and the second laser projector 17 is the second drive circuit. Rotation angle φ from rotation angle detector 15 at 25
The output is controlled on the basis of the above.

The signals from the two solar cells received by the laser light receiving section 22 are sent to the light receiving element recognition section 26 and the distance l is calculated by the calculation section 27.
Output to.

 Next, the operation of detecting the position of the bulldozer 2 will be described.

As shown in FIG. 5, the distance R between the laser projector 1 and the laser receiver 3 is And θ is known, the first and second laser light 18,1
The distance R between the laser projector 1 and the laser receiver 3 can be measured by measuring the light receiving distance l of the laser receiver 22 of 9.

Therefore, the calculation unit 27 determines the distance 1 between the light received from the light receiving element recognition unit 26 and the angle setting device 2 for the first and second laser beams 18 and 19.
A first arithmetic circuit 29 for calculating the distance R between the laser projector 1 and the laser receiver 3 by calculating the above equation from the angle θ from 8 is provided.

In addition, the output P ₁ of the first laser light 18 and the second laser light 18 are generated by the output voltages of the solar cells 23a and 23b that have received the first laser light 18 and the second laser light 19 in the laser light receiving unit 22.
A second arithmetic circuit 30 for calculating the rotation angle φ of the laser projector 1 from the ratio of the output P ₂ of 19 is provided in the arithmetic unit 27.

That is, since the output of the second laser light 19 is proportional to the rotation angle φ, the output P ₁ of the first laser light 18 and the second laser light 19
The rotation angle φ of the laser projector 1 is obtained by the ratio P ₂ / P _{2 to} the output P ₂ .

The reason for obtaining the ratio of the laser light outputs is as follows.

Generally, laser light attenuates in inverse proportion to the propagation distance when propagating in the atmosphere. When the refractive index of the atmosphere changes due to changes in temperature and humidity, the rate of reduction of laser light also changes.

When the attenuation rate of the laser light is α and the conversion efficiency of the solar cell is η, the output P ₁ of the solar cell 23a that receives the first laser light 18 and the output P _{2 of} the solar cell 23b that receives the second laser 19
Are P ₁ = αηP ₁ and P ₂ = αηP ₂ , respectively.

If you take the ratio of both Therefore, it is understood that the output ratio of the solar cell is not related to the attenuation rate α and the conversion efficiency η.

From the above, from the distance R between the laser projector 1 and the laser receiver 3 and the rotation angle φ of the laser projector 1, the position of the laser receiver 3, that is, the position of the bulldozer 2 is set to the origin of the laser projector 1 as shown in FIG. It can be detected by the X and Y coordinates set to 0.

That is, since the X coordinate is Rcosφ and the Y coordinate is Rsinφ, the third arithmetic circuit 31 for performing this arithmetic operation is provided in the arithmetic unit 27.

In this case, the projection direction of the first and second laser lights 18 and 19 at the position where the laser projector 1 starts rotating is set to the X direction, for example, north direction.

Further, as shown in FIG. 9, when the reference H is set by the solar cell that receives the first laser beam 18 and the height from the lower end of the laser receiving portion 22 to the light receiving position is h, the position in the height direction is H−. It can be calculated by h.

〔The invention's effect〕

Since only one laser projector 1 needs to be installed at the reference point of the moving area, the cost of the entire apparatus can be reduced and the installation work of the laser projector 1 can be simplified.

[Brief description of drawings]

The drawings show an embodiment of the present invention, FIG. 1 is an overall perspective view, FIG. 2 is a detailed view of a laser projector, FIG. 3 is a table showing the output of the first and second laser beams, and FIG. 4 is a laser. FIG. 5 is a perspective view of the light receiving part, FIG. 5 is an explanatory view of the light receiving states of the first and second laser beams, FIG. 6 is a schematic view of the laser projector and the laser light receiver, FIG. FIG. 9 is an explanatory diagram of position detection, and FIG. 9 is an explanatory diagram of detection in the height direction. Reference numeral 1 is a laser projector, 3 is a laser receiver, 18 and 19 are first and second laser beams, 22 is a laser receiver, and 27 is a calculator.

Claims (1)

[Claims] 1. A first laser beam (18) and a second laser beam (19) projected at an angle (θ) in a vertical plane at a reference point of a moving area, and the first laser beam (18). The laser light (18) is always constant output, and the second laser light (19) has an output proportional to the rotation angle (φ) from the reference azimuth. The laser projector (1) is rotatably installed in the horizontal plane and moved. The body has a laser receiving section (22) capable of receiving light in all directions and the first and second sections.
The rotation angle (φ) of the laser projector (1) and the distance (R) to the laser projector (1) are calculated based on the light receiving states of the laser beams (18) and (19), and the rotation angle (φ) and the distance (φ) are calculated. A position detector for a moving body, characterized in that a laser receiver (3) having a calculation unit (27) for calculating the position based on R) is attached.