JPH0633019U - Position detector - Google Patents

Abstract

(57) [Summary] [Purpose] Eliminates cable splicing associated with the movement of moving objects. [Configuration] Targets 24 and 26 are laser beams 28
An electric signal corresponding to the hit position is output to the spot position calculator 32, and the spot position calculator 32 determines the spot position of the laser beam 28 on the targets 24 and 26. The modulation circuit 34 gives the position information obtained by the spot position calculator 32 to the liquid crystal drive circuit 48 of the optical signal output section 40 as a signal combining "H" and "L". In the optical signal output unit 40, the beam splitter 42 guides a part of the laser beam 28 to the reflecting mirror 44, and the liquid crystal drive circuit 48 causes the reflecting mirror 4 to move.
The liquid crystal plate 46 provided on the front surface of the laser diode 4 is driven to block and transmit the laser beam 28 incident on the reflecting mirror 44, and the modulation circuit 3
The optical signal 50 corresponding to the output signal of No. 4 is emitted.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a device for detecting a relative position with respect to a reference point, and more particularly to a position detection device suitable for sending the detected position data to a point away from a moving body such as an underground excavator.

[0002]

[Prior art]

 When excavating the ground with an underground excavator, it is necessary to control the posture and direction of the underground excavator so that the tunnel being excavated is along the planned line. Then, in recent years, the position and position of an underground excavator with respect to a reference point have been detected using a position detection device using laser technology.

In this conventional position detecting device, a target composed of an optical position detecting element using a solar cell is arranged at the tip of an underground excavator excavating underground, and a start point, for example, a start point, is used as a reference point. A laser beam is emitted from a laser projector installed in a vertical shaft to a target, the position of the laser beam hitting the target is determined based on the output signal of the target, and the positional relationship of the tip of the underground excavator to the reference point is determined. I am asking for it. Then, the position information obtained from the output signal of the target is converted into an electric signal, led to the reference point provided with the laser projector through the cable, and displayed on the display unit of the control unit provided on the reference point side. ing.

[0004]

[Problems to be solved by the device]

 By the way, the conventional position detecting device needs to transmit the position information of which part of the target the laser beam hits to the reference point by the cable as described above. For this reason, as the tip of the underground excavator digs into the ground, it is necessary to pull out the cable and, if necessary, add cables. However, this cable extension work is time-consuming and reduces the efficiency of excavation work. Moreover, since the cable replenishment work is performed in a situation where there is a lot of mud, the contact of the connector is likely to be incomplete when replenishing the cable, which often causes a problem that position information is not transmitted.

The present invention has been made in order to solve the above-mentioned drawbacks of the prior art, and an object of the present invention is to provide a position detection device capable of eliminating a cable replenishment accompanying the movement of a moving body.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, the position detection device according to the present invention receives a laser beam emitted from a laser projector and outputs a target electric signal corresponding to a light receiving position and a target output signal based on the target output signal. A position calculator for obtaining the irradiation position of the laser beam on the target, and an optical signal output section for emitting the position information obtained by the position calculator as an optical signal.

The optical signal output unit includes a reflecting mirror, a beam splitter that guides a part of the laser beam incident on the target to the reflecting mirror, a shutter that is arranged in the optical path of the laser beam, and blocks and passes the laser beam. A shutter drive unit that drives the shutter based on the output of the position calculator can be used. The shutter is preferably a liquid crystal plate, but may be mechanical. The optical signal output unit may use a laser oscillator such as a semiconductor laser.

[0008]

[Action]

 In the present invention configured as described above, the optical signal output unit outputs the laser beam irradiation position on the target obtained by the position calculator into the air as an optical signal. Therefore, if a photoreceiver for receiving an optical signal is provided on the side of the reference point where the laser projector is installed, it is possible to omit the conventionally required cable. As a result, even if a moving body such as an underground excavator equipped with a position calculator moves forward, it does not need to perform work such as cable extension and replenishment, and there is no problem that position data is not transmitted due to poor contact of the connector. You can

[0009]

【Example】

 A preferred embodiment of the position detecting device according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is an explanatory diagram of a position detecting device according to a first embodiment of the present invention.

In FIG. 1, the position detection device 20 has a sensor portion 22 provided at the inner tip of the underground excavator 10. The sensor unit 22 has a pair of targets 24 and 26 arranged in parallel at a predetermined interval. Each of these targets 24 and 26 is composed of a two-dimensional semiconductor position detecting element (PSD) using, for example, a Si photodiode, and outputs an electric signal corresponding to the position where the light hits.

A laser projector 30 that emits a laser beam 28 toward the sensor unit 22 is installed at a reference point (for example, a shaft) behind the underground excavator 10. A spot position calculator 32 is connected to each of the targets 24 and 26 of the sensor unit 22. The spot position calculator 32 determines the spot position of the laser beam 28 irradiated on the targets 24 and 26 from the output signals of the targets 24 and 26. Then, the position information obtained by the spot position calculator 32 is converted into a binary code by the modulation circuit 34.

On the other hand, a beam splitter 42 forming an optical signal output unit 40 is inserted in the optical path of the laser beam 28 in front of the sensor unit 22 (on the side of the laser projector 30), and a part of the laser beam 28 is inserted. Is guided to the reflecting mirror 44. The reflecting mirror 44 can reflect the beam incident from the beam splitter 42 to the reference point side. A liquid crystal plate 46 is provided on the front surface of the reflecting mirror 44. The liquid crystal plate 46 is connected to a liquid crystal drive circuit 48 controlled by the modulation circuit 34, and serves as a shutter for blocking and passing the laser beam from the beam splitter 42.

The optical signal 50 emitted from the reflecting mirror 44 is made to enter a light receiver 52 provided at a reference point. The light receiver 52 is composed of, for example, an optical sensor such as a phototransistor, and converts the received optical signal 50 into an electric signal and inputs the electric signal to the signal analysis device 54. Then, the signal analysis device 54 obtains the spot position of the laser beam 28 irradiated on the targets 24 and 26 based on the optical signal 50 received by the light receiver 52, and displays it on the display device 56.

The operation of the embodiment configured as described above is as follows. A part of the laser beam 28 emitted by the laser projector 30 passes through the beam splitter 42 of the optical signal output unit 40 and is applied to the targets 24 and 26 of the sensor unit 22. Each of the targets 24 and 26 inputs an electric signal corresponding to the spot position of the irradiated laser beam 28 to the spot position calculator 32. Then, the spot position calculator 32 calculates the irradiation position of the laser beam 28 on each target 24, 26 from the output signal of each target 24, 26, and sends the obtained irradiation position information to the modulation circuit 34. . The modulation circuit 34 also modulates the position information obtained by the spot position calculator 32 into a binary code composed of a combination of “H” and “L”, and the liquid crystal drive circuit 48 of the optical signal output section 40. Give to.

On the other hand, the optical signal output unit 40 guides a part of the laser beam 28 which the beam splitter 42 enters the sensor unit 22 to the reflecting mirror 44. Then, the liquid crystal drive circuit 48 drives the liquid crystal plate 46 provided on the front surface of the reflection mirror 44 based on the output signal of the modulation circuit 34 to cut off and transmit the laser beam 28 incident on the reflection mirror 44, and Output signal 50.

That is, the liquid crystal plate 46 does not transmit light in a normal state, and when a voltage is applied from the liquid crystal drive circuit 48, the orientation of the molecules changes to transmit light. Then, the liquid crystal drive circuit 48 applies a voltage to the liquid crystal plate 46 when the modulation circuit 34 outputs “H”, makes the laser beam 28 guided from the beam splitter 42 incident on the reflecting mirror 44, and reflects it. The optical signal 50 is output from the mirror 44. Further, when the modulation circuit 34 outputs “L”, the liquid crystal drive circuit 48 shuts off the voltage applied to the liquid crystal plate 46, shuts off the laser beam 28 from the beam splitter 42, and the laser beam 28 is reflected by the reflecting mirror. It is prevented from entering 44. Therefore, the reflecting mirror 44 outputs the optical signal 50 corresponding to the combined signal of “H” and “L” output from the modulation circuit 34 toward the light receiver 52.

The light receiver 52 receives the optical signal 50 output from the reflecting mirror 44, converts the optical signal 50 into an electric signal, and outputs the electric signal to the signal analyzer 54. The signal analyzer 54 finds the positions where the laser beams 28 hit the targets 24 and 26 as in the conventional case, and determines the reference from the distance between the targets 24 and 26 and the beam positions hitting these targets 24 and 26. The position, the excavation direction, etc. of the sensor unit 22, that is, the underground excavator 10 with respect to the laser projector 30 installed at the point is calculated and displayed on the display device 56.

As described above, in the position detecting device 20 of the embodiment, since the reflecting mirror 44 outputs the position information obtained by the spot position calculator 32 as the optical signal 50, it is conventionally required. The signal cable can be omitted. As a result, it is not necessary to pay out the cable as the underground excavator 10 advances, it is possible to improve the work efficiency by eliminating the cable splicing work, and the data is not transmitted due to the contact failure of the connector. Can be eliminated.

Although the liquid crystal plate 46 is used as the shutter in the above embodiment, a mechanical shutter may be used. Further, although the case where the liquid crystal plate 46 is mounted on the front surface of the reflecting mirror 44 has been described in the above embodiment, the installation position of the liquid crystal plate 46 is not limited to the embodiment. That is, for example, the liquid crystal plate 46 may be arranged to transmit light in a normal state and be arranged on the beam incident side of the beam splitter 42.

FIG. 2 is an explanatory diagram of the second embodiment. In the second embodiment, the optical signal output section 40 of the first embodiment is replaced by a laser diode 60 which is a semiconductor laser as a laser oscillator, and a diode drive circuit 62 which drives the laser diode 60. A signal output unit 64 is provided, and the optical signal 50 output from the laser diode 60 is input to the photodetector 52 via the telescope 66.

In the second embodiment, the diode drive circuit 62 drives the laser diode 60 according to the output signal of the modulation circuit 34, and the combination of “H” and “L” output from the modulation circuit 34 is used. The optical signal 50 corresponding to the signal is emitted. Then, the optical signal 50 is received by the photodetector 52 via the telescope 66, and the same processing as in the first embodiment is performed thereafter. Therefore, the second embodiment does not require a cable for transmitting position information, and the same effect as that of the first embodiment can be obtained. The laser oscillator may be another device such as a glass laser.

[0022]

[Effect of device]

 As described above, according to the present invention, since the position information obtained by the position calculator is emitted into the air as an optical signal, the cable conventionally required can be omitted, and the underground unit equipped with the position calculator can be omitted. Even if a moving body such as an excavator moves forward, it is possible to eliminate the work such as paying out the cables and reconnecting them, and to eliminate the problem that the position data is not transmitted due to poor contact of the connector.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a position detection device according to a first embodiment of the present invention.

FIG. 2 is an explanatory view of a position detecting device according to a second embodiment of the present invention.

[Explanation of symbols]

 10 Underground excavator 20 Position detector 22 Sensor part 24, 26 Target 30 Laser projector 32 Position calculator (spot position calculator) 40, 64 Optical signal output part 42 Beam splitter 44 Reflector 46 Shutter (liquid crystal plate) 48 Shutter Drive circuit (liquid crystal drive circuit) 50 Optical signal 60 Laser diode

Claims (5)

[Scope of utility model registration request] 1. A target for receiving a laser beam emitted from a laser projector and outputting an electric signal corresponding to a light receiving position, and a position calculation for obtaining an irradiation position of the laser beam on the target based on an output signal of the target. And a light signal output section for outputting the position information obtained by the position calculator as an optical signal. 2. The optical signal output unit is disposed in the optical path of the laser beam, a reflecting mirror, a beam splitter that guides a part of the laser beam incident on the target to the reflecting mirror, and the laser beam. The position detecting device according to claim 1, further comprising: a shutter for blocking and allowing the shutter to pass, and a shutter drive unit for driving the shutter based on an output of the position calculator. 3. The position detecting device according to claim 2, wherein the shutter is a liquid crystal plate. 4. The position detecting device according to claim 1, wherein the optical signal output unit is a laser oscillator. 5. The position detecting device according to claim 4, wherein the laser oscillator is a semiconductor laser.