JPS60134309A - Tracking device of moving body utilizing optical beam - Google Patents

Abstract

PURPOSE:To obtain an exact tracking and a position measured value of a good quality by using a scanner provided with high speed and high speed deflecting devices. CONSTITUTION:A fixed station 100 of a tracking device is constituted of an optical beam generating device 110, a modulating device 111, scanners 130, 140, a splitter 150, a detecting device 170, and their control device 180. Also, a mobile station 200 is constituted of a reflecting means 210 of an optical beam LB1, a splitter 220 and a demodulating device 240. In this case, the scanners 130, 140 of the fixed station 100 are constituted of a low speed polarizing device 130 and a high speed polarizing device 140. In this way, as for a large movement of a slow amplitude of the mobile station 200, and quick movement of a small amplitude of said station, the laser beam LB1 irradiated from the fixed station 100 can be made to follow sufficiently by the device 130 of a low speed side and the device 140 of a high speed side, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a tracking device for a moving object, which uses a light beam to track, communicate, and measure the position of a moving object, particularly a high-speed moving object.

(b) Prior Art Conventionally, in order to perform wide-range tracking, it was necessary to operate a large mirror to receive the reflected beam from the target object and track it in the direction of the moving object, which caused the mass of the moving parts to increase. Due to the increase in the moment of inertia, the response deteriorated, and the problem was that it was unable to follow moving objects that changed course at high speed.

(C) Objective The present invention was made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a tracking device for a moving object using a light beam that can follow even high-speed course changes of the moving object.

(b) Structure The present invention provides a fixed station comprising a scanner equipped with a light beam generator, a modulator, a low-speed and a high-speed deflection device, a splinter, a detection device, and a control device, and a light beam reflection device. The mobile station consists of a means, a splitter, and a demodulator.

(B) Embodiment FIG. 1 is a perspective view illustrating the present invention in detail.
This is a fixed station and consists of the following:

110 is a light beam generator, 111 is a modulator,
A laser beam LBI modulated with a desired signal is emitted as shown by the arrow, passes through a high-speed deflection device 140 composed of a vertical deflection element 142 and a left and right deflection element 141, receives a desired deflection, and is sent to a splitter 150. The light passes from the back surface and is reflected in a desired direction in three-dimensional space by a mirror 131 controlled by an X-axis mirror 132 and a Y-axis mirror 133.

The laser beam LBI emitted into the three-dimensional space is reflected by a moving body as described later, returns to the fixed station as a reflected beam LB2 parallel to the laser beam LBI, is reflected again by the mirror 131, and is further reflected by the splitter 150. The optical path is changed to a substantially right angle, and the light is focused by the lens system 160.
The detection surface of the detector 170, which is divided into four quadrants, is irradiated.

180 is a control device that processes the output signal from the detector 170 and generates a signal for driving the low-speed deflection device 130 and the high-speed deflection device 140.

Reference numeral 200 denotes a mobile station mounted on a mobile body, in which the laser beam LBI incident from the fixed station 100 is reflected by a corner cube 210 serving as a reflecting means. It is reflected in the direction of the fixed station 100 as a reflected beam LB2 parallel to B1.

On the other hand, the incident laser beam 1. In the past, a part of the light beam ζ was changed in its optical path by a splinter 220 placed in front of the corner cube 210, focused by a lens system 230, and then incident on a demodulator 240.

The demodulator 240 is equipped with a light receiving element, a demodulator circuit, etc. as described later, and extracts and outputs the signal transmitted by modulating the laser beam LBI from the fixed station 100 as described above. - FIG. 2 is a block diagram, and as described above, the reflected beam LB2 from the moving object is reflected by the mirror 131 and the splitter 150, condensed by the lens system 160, and incident on the detector 170.

As described above, the detector L70 is composed of, for example, a solar cell divided into four quadrants.

Thus, the irradiation direction of the laser beam LBI is controlled by the low-speed deflection device 130 and the high-speed deflection device 140 so that the incident amount of the reflected beam LB2 in each quadrant is equal.

That is, the outputs of the four quadrants of the detector 170 enter the sensor circuit 181, and are input as digital signals to the deflection signal generation circuit 182 via the respective light receiving circuits 1811, filters 1812, and A/D converters 1813. The position determination circuit 1821 determines the direction in which the deflection device should be driven by comparing the signals of the left and right detector quadrants, and the upper and lower detector quadrants, respectively, and also determines the direction in which the deflection device should be driven.
22, the processing is determined.

The left and right signals output from the position determination circuit 1821 are input to a pulse counter 1823, and the up and down signals are input to a pulse counter 1824 as control signals.

Therefore, the pulse counters 1823 and 1824 count the input pulses of the pulse generator 1825 based on the control signal, and send the output to the I)/A converters 1826 and 1827.
give to

In the low-speed deflection drive circuit 183, the left and right and up and down direction signals are respectively input to a deflection angle determination circuit 1832 via an LP filter 1831, which converts the signals into a motor rotation angle signal, and a pulse generator by a pulse switching circuit 1833. The pulse train from 1834 is applied as a switching digital signal to the X-axis motor 132 or the Y-axis motor 133 via the drive circuit 1835 to direct the mirror 131 in a desired direction.

Note that in the above operation, as described above, the input signal to the low-speed deflection drive circuit 183 passes through the LP filter 1831, high-speed signals are removed, and only low-speed tracking is performed due to the influence of the moment of inertia of the mirror. .

On the other hand, the horizontal and vertical signals from the deflection signal generation circuit 182 are also respectively input to the high speed deflection drive circuit 184, and the low speed signals are removed via the IIP filter 1841.

Therefore, the signal for fast deflection is VC01842,
The signal is applied to the left and right deflection elements 141 or the top and bottom deflection elements 142 of the high-speed deflection device 140 via a drive circuit 1843. The incident laser beam LBI is given a desired deflection by diffraction and passes through the splitter 150 to the mirror 131.
reflected in the desired direction.

In this case, the laser beam LBI in the high-speed deflection device 140
The deflection is performed, for example, by diffraction using an acousto-optic element. Since the acousto-optic element does not involve the movement of an object, it can sufficiently follow high-speed signals. Therefore, in combination with the low-speed deflection described above, it is possible to follow any movement of the moving body.

Furthermore, the laser beam LB from the light beam generator w110
I enters the modulator 1111 of the modulation device 111, receives a desired signal to be transmitted to the moving object from the modulation circuit 1112, is modulated, and is sent to the high-speed deflection device 140 as a laser beam LBI.
is ejected to.

Further, at the mobile station 200, the incident laser beam LBI is reflected by the corner cube 210 toward the fixed station as a reflected beam LB2 parallel to the incident beam. Further, a part of the incident laser beam LBI is changed in its optical path by the splitter 220, is focused by the lens system 230, and is incident to the demodulator 240.

In the demodulator 240, the incident laser beam LBI is converted into a power receiver signal by the light receiving element 2401, and then the amplifier 24
02, the transmission signal from the fixed station is taken out via the demodulation circuit 2403, the discrimination circuit 2404, and the output circuit 24O5.

As mentioned above, by using the two low-speed and high-speed deflection devices together, the fixed station cuff can be illuminated even when the mobile station moves slowly with a large amplitude, or when it moves fast with a small amplitude. The laser beam can be tracked sufficiently. To demonstrate this situation, FIG. 3 shows the overall frog deflection characteristics when a step input is applied to the circular deflection device. .

(C) shows the overall response characteristic that combines both of them, and shows that it is possible to follow the movement of high and low T tags in a sufficiently short time.

In the embodiments described above, the high-speed deflection device was described as consisting of two acoustic and optical elements arranged in such a way that the diffraction gratings are orthogonal to each other.

However, this invention is limited to, for example,
Small 0°° with sufficiently small inertia and moment.
This mirror only receives the light beam irradiated from the light beam generator 1, as described above. 1. Considering the projection range of the reflected beam like a mirror: It is not necessary, so the shape can be made sufficiently small.

By using the device of the present invention, it is possible to perform not only normal movement of a moving object but also rapid course change or movement.
-2;2<,,: ::c;'l: It is possible to obtain the f-con X position measurement value and perform high-quality information conversion.1
You can achieve the desired effect.

[Brief explanation of drawings]

, Figure 2 is a perspective view illustrating an embodiment of the present invention;
The surface is shown on page i1. The block diagram of the embodiment, FIG. 3, is a step and response diagram of the deflection device 2. 1O0・Fixed station, 1 jo,...: Light beam generator 1.139...Low speed deflection device, 140 direction device, 150...□・Splitter, 170...Detector, 18p・...control device, 200 ...mobile station,
21...Corner cube, 220...Sprinter, 240 Pa...Demodulator. Patent applicant: Hitachi Kiden Kogyo Co., Ltd. Agent: Patent attorney: Takaharu Ohnishi

Claims (3)

[Claims] (1) A light beam generator, a modulator that modulates the generated light beam with a desired signal, a scanner that scans the light beam in three-dimensional space, and an optical path of the reflected beam from the mobile station of the light beam. A fixed station comprising: a splinter that changes the optical path; a detector that detects the reflected beam whose optical path has been changed; and a control device that determines the position of the mobile station based on the output of the detector and controls the scanner. and,
a reflecting means for reflecting the incident light beam as a reflected beam parallel to the incident beam; a splinter for branching a part of the incident beam; and a splinter for detecting the branched light beam and detecting the transmitted signal. A tracking device for a mobile object, comprising a demodulator for extracting the data, and a mobile station configured with a demodulator for extracting the data.
A tracking device for a moving object using a light beam, characterized in that the scanner comprises a low-speed deflection device that uses a motor to drive a mirror held by two orthogonal axes, and a high-speed deflection device. (2) Tracking of a moving object using a light beam according to claim 1, wherein the high-speed deflection device is comprised of two acousto-optic elements whose diffraction gratings are arranged orthogonal to each other. Device. (3) A moving body using a light beam according to claim 1, wherein the high-speed deflection device holds a small mirror on two orthogonal axes and drives this with a motor. tracking device.