JPS6312911A - Reference direction correcting laser projector - Google Patents

Abstract

PURPOSE:To improve position measurement accuracy by detecting the error in rotary synchronism between two laser projectors and correcting the relative error between both reference azimuth signals in real time. CONSTITUTION:The two laser projectors 1 and 2 emit laser light beams 8 and 9 while rotated synchronously by a synchronous controller 5 about two fixed points A and B in the same directions. The laser light beams 8 and 9 which scan within the area are detected by ground photodetectors 3 and 4 and a photodetector 14 on a vehicle P moving in this area and their photodetection outputs are processed by a reference azimuth detecting circuit 6 and a photodetection angle detecting circuit 15. Then, the photodetectors 3 and 4 generate reference azimuth detection signals 10 and 11 and the time difference between both signals is measured and transmitted to the area from a communicating device 7 as a reference azimuth correcting signal 13. The vehicle side inputs the photodetection output of the photodetector 14 and the signal 13 received from the device 7 to the circuit 15 to obtain a photodetection angle output signal. Thus, the error in the rotary synchronism between the projectors 1 and 2 is detected as the signal in real time and the error is corrected on the vehicle side to obtain the accurate photodetection angle detection signal, thereby improving the position measurement accuracy.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a system for measuring the position of a moving object within a working area using a 9-rotation laser beam, and particularly relates to a system for measuring the position of a moving object within a working area using a 9-rotation laser beam. The present invention relates to a rotary laser projector in a system in which a rotating laser projector is installed to scan an area with a laser beam and measure the position of a moving object using the principle of triangulation.

(Conventional technology) In order to save labor and automate outdoor work, it is essential at construction sites to measure the position of work vehicles within the area, so two rotating laser projectors are installed in one work area. A system has already been proposed in which the position of a moving object is measured by scanning the area with a laser beam and using the principle of triangulation.

That is, for example, as described in Japanese Patent Publication No. 52-1521, the time difference in which laser light passes in both directions of the reference direction connecting two rotating laser projectors and the direction of the moving object is measured, and A system that calculates the angle formed by the object and applies the principle of triangulation has been proposed and is publicly known.

(Problems to be Solved by the Invention) In the conventional system as described above, a reference azimuth signal is shared on the premise that the rotations of the two laser projectors are synchronized with high precision.

In reality, it is inevitable that errors in rotation synchronization between the two laser projectors will occur due to differences in the characteristics of the rotation drive parts of the two laser projectors or changes in the environment. have

An object of the present invention is to eliminate such problems.

(Means and effects for solving the problem) This invention has been made in view of the above problem, and includes two laser projectors that rotate and emit laser light, and A synchronization control circuit synchronizes the rotation of the two installed light receivers and the two laser projectors.

a reference direction detection circuit that processes the outputs of the two light receivers;
The device is equipped with a communication device that transmits a reference direction correction signal into the area based on this detection signal, detects rotation synchronization deviation of the two laser projectors, and corrects the relative error between the two reference direction signals in real time. This greatly improves the accuracy of single-position measurement.

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

FIG. 1 shows a block diagram of the configuration of the reference direction correction laser projector of the present invention, and FIG. 2 shows a moving vehicle P and a
This diagram schematically shows the positions of two laser projectors installed at fixed points A and B.

In these figures, two laser projectors 1.2 are installed at two fixed points A and B to rotate the laser beam 8.9, and two receivers 3.4 are installed at two fixed points A and B, respectively. The laser projector 1.2 is installed at the 91 point A' on the straight line A' and B' connecting the laser projectors 1 and 2. 5 is a synchronization control circuit that synchronizes the rotation of the two laser projectors 1 and 2, and 6 is a reference direction detection circuit that processes the outputs 10 and 11 of the two light receivers 3 and 4 and generates a detection signal 12. is transmitted to the communication device 7, and the communication device 7 transmits the reference direction correction signal 13 into the area.

Next, the operation of the device shown in FIG. 1 will be described based on FIGS. 2 and 3.
The laser beams 8 and 9 are emitted while rotating synchronously in the same direction around two fixed points A and B. Here, assuming a moving vehicle P within the area, the on-vehicle light receiver is assumed to be 14. The laser light 8.9 scanning within the area is detected by the ground light receivers 3, 4 and the vehicle-mounted light receiver 14, and processed by the reference direction detection circuit 6° and the receiving angle detection circuit 15. That is, as shown in FIG. 3, the laser beams 8 and 9 are received and detected by the ground receiver 3.4, a reference direction detection signal 10.11 is generated, the time difference t between the two signals is measured, and the communication device 7 The reference direction correction signal 13 is transmitted from within the area. Also, on the vehicle side, the in-vehicle light receiver 14
The received light output S and the reference azimuth correction signal 13 received by the in-vehicle communication device are input to the received light angle detection circuit 15 to obtain detected light angles Sα and Sβ.

The error expressed as Δβ=2π×□ is corrected.

As described above, the rotation synchronization error between the two laser projectors, which has been a problem in the past, can be detected in real time as the reference azimuth correction signal 13, and this error can be corrected on the vehicle side to achieve accurate light reception angle detection Sα.

By obtaining Sβ, position measurement accuracy can be improved.

FIG. 4 shows a case where the present invention is applied to a position measuring system for a working vehicle operating at a construction work site.

FIG. 5 specifically shows the laser projector 1.2.

Laser oscillator 211 Oscillation control circuit 221 Rotation motor 2
31 rotation prism head 24. It consists of a 3m25 elevator.

The light receiver 3.4 has a light receiving surface 26° and a light receiving element 27.4 as shown in FIG. Light reception detection circuit 28. It consists of a light receiving monitor 29° and an elevating tripod 30.

As shown in FIG. 7, the synchronization control circuit 5 includes a reference oscillator 319 and a phase comparison circuit 32a common to the laser projectors 1 and 2.
, 32b, low-pass filter 33a.

33b, power amplifiers 34a, 34b, amplification shaper 35a
.

35b.

Thus, according to the embodiments of this invention.

It can provide a highly accurate work vehicle measurement system for outdoor work such as civil engineering construction sites.

(Effect of the invention) This invention is constructed as described above in detail.

Detect rotation synchronization deviation of two laser projectors.

By correcting the relative error between the two reference direction signals in real time, the position measurement accuracy can be significantly improved. Therefore, a highly accurate work vehicle position measurement system for outdoor work such as civil engineering construction sites can be obtained, and one task can be automated. , it is possible to achieve unmanned operation.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a reference direction correction laser projector according to an embodiment of the present invention. Figure 2 schematically shows the arrangement relationship between a moving vehicle and two laser projectors, Figure 3 is a timing chart showing the operation of the one in Figure 1, and Figure 4 shows how this device is installed at a construction work site. 5 shows a specific example of a laser projector, FIG. 6 shows a specific example of a light receiver, and FIG. 7 shows a specific example of a synchronous control circuit. 1.2... Laser emitter, 3,4... Light receiver. 5... Synchronous control circuit. 6... Reference direction detection circuit, 7... Communication device. Patent Applicant Komatsu Ltd. Agent (Patent Attorney) Osamu Matsuzawa 1i1 Figure ii2 Figure 3 Pictorial 5

Claims (1)

[Claims] Two laser projectors that emit rotating laser beams;
Two light receivers installed on a straight line connecting the two laser projectors, a synchronization control circuit that synchronizes the rotation of the two laser projectors, and a reference direction detection circuit that processes the output of the two light receivers. and a communication device that transmits a reference azimuth correction signal into the area based on the detection signal.