JPS6256029A - Controller for optical communication between mobile bodies - Google Patents

Abstract

PURPOSE:To attain optical communication for a long time by providing the 1st and 2nd photodetectors, a drive means and an optical axis direction control means. CONSTITUTION:The optical axis of an incident light beam LA and of an irradiated light beam LB are coincident and when a vehicle of the light transmission side is curved and the light beam LA comes to a light beam LA', the optical axes of the light beams LA', LB are not coincident. In this case, the photodetection quantity of a photodetector 40 is more than that of the photodetector 38 and the turning body 26 is turned clockwise so that the photodetection quantity of the photodetector 38 is coincident with that of the photodetector 40, then the optical axes of the incident light beam LA' and the irradiated light beam LB' are coincident to attain the optimum transmission/reception state. In applying the tracking control to the optical axis in this way, even when the vehicle of the transmission side or the reception side is curved, the optical communication is attained continuously.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for optical communication between moving bodies used for optical communication between vehicles and the like.

[Prior Art] The present inventor has devised an inter-mobile optical communication KC device for transmitting and receiving audio signals by optical communication (Japanese Patent Application No. 59-234600), which will be explained using FIG. 8(A). .

Vehicles CA and CB are moving in the direction of arrow X. Vehicle CA
Light transmitters/receivers A1, A2 are provided at the front and rear of the vehicle CB, respectively, and light transmitters/receivers B1, B2 are similarly provided at the front and rear of the vehicle CB. These transmitters and receivers At
, A2. Bl and B2 have the same configuration. Vehicle C
The outline of the case where the audio signal is transmitted from the B side to the vehicle CA side is as follows. A aiming light beam LA is sent from the light transmitter/receiver A2 toward the light transmitter/receiver B1. When the reception intensity by the light transmitter/receiver Bl is higher than a certain value, it means that the optical axes of the light transmitter/receiver A2 and the light transmitter/receiver Bl substantially coincide with each other, and the light transmitter/receiver B
The audio signal is time-base compressed and transmitted from the light beam LB to the light transmitter/receiver A2. The vehicle CA side receives this, expands the time axis, and reproduces the audio.

Therefore, even when the vehicle is traveling on an uneven road surface, audio signals can be transmitted and received through optical communication. According to this optical communication, there are no problems with regulations under the Radio Law, and there are no problems with radio wave interference or interference.

Furthermore, since the transmission range is limited, confidentiality is excellent.

[Problems to be Solved by the Invention] 1. or 17. As shown in FIG. 8(B), when the vehicle CA curves, the optical axes of the light beams 1, LA and LB do not coincide, so the light beams Communication becomes impossible.

SUMMARY OF THE INVENTION In view of the drawbacks mentioned above, it is an object of the present invention to provide a control device for optical communication between moving bodies that can continue optical communication even when a vehicle curves, pitches, rolls, etc. .

[Means for Solving the Problems] The control device for optical communication between moving objects according to the present invention is provided on a rotating body that rotates the direction of the optical axis of transmitted light, and is spaced apart at a position where the received light is focused and incident. A first light receiving element and a second light receiving element arranged in the same direction, a driving means for rotationally driving the rotating body, and a driving means for rotationally driving the rotating body so that the difference between the detection signals from the first light receiving element and the second light receiving element becomes zero. and an optical axis direction control means for feedback controlling the rotation angle, so that the optical axis direction of the transmitted light coincides with the optical axis direction of the received light.

[Function] The light beam emitted from the transmitter/receiver of the other party is used as the first
It is detected by the light receiving element and the second light receiving element.

If the difference between these detection signals is not zero, the rotation angle of the rotating body is feedback-controlled by the optical axis direction control means so that the difference becomes zero.

As a result, the optical axis direction of the transmitted light coincides with the optical axis direction of the received light, and as shown in FIG. 8(C), optical communication is possible even if the vehicle curves.

[Example] Embodiments of the present invention will be described with reference to the drawings.

As shown in FIG. 8(C), light transmitters and receivers A3. A4 is provided. Also,
Similarly, light transmitters and receivers B3 and B4 are provided at the front and rear portions of the vehicle CB, respectively. These transmitter/receiver A3
, A4, B3, and B4 have the same configuration, and the first
The configuration is shown in the figure.

The housing 12 of the light transmitter/receiver B3 has a large cylindrical portion 14 on the right side. A filter 16 is attached to an opening at one end of the large cylindrical portion 14 to cut out background light such as sunlight and improve the S/N ratio. Large cylindrical portion 14 facing filter 16
A concave mirror 18 is provided on the bottom surface of the mirror 18 to focus the incident light beam. A small cylindrical portion 20 is protruded from the circumferential surface of the large cylindrical portion 14, and a light emitting element 22 is fixed to the bottom surface of the small cylindrical portion 20. Further, a convex lens 24 is fixed to the small cylindrical portion 20 in front of the light emitting element 22, and converts the light emitted from the light emitting element 22 into parallel light.

A rotating body 26 is pivotally supported in the center of the large cylindrical portion 14 via an arm 28. The arm 28 is bent into a crank shape, and one end thereof is fixed to the side surface of the rotating body 26. One of the shafts 30, which is the other end of the arm 28, is attached to the rotating shaft of a DC motor 32 fixed to the large cylindrical section 14, and the other is attached to the rotating shaft of a potentiometer 34 fixed to the large cylindrical section 14. is attached to. Therefore, it is possible to rotate the rotating body 26 about the shaft 30 by the DC motor 32 and read the rotation angle by the change in the resistance value of the potentiometer 34.

The rotating body 26 has a cylindrical shape, and a light receiving element 36 is fixed to the center of the bottom surface on the concave mirror 18 side to detect an incident light signal. .40 is fixed to the bottom surface of the rotating body 26 at a certain distance, and the optical axis direction of the incident light beam can be detected from the difference in the amount of light received by the light receiving elements 38 and 40.

The other bottom surface of the rotating body 26 is 4
It is inclined at 5 degrees, and a plane mirror 42 is provided on this. This plane mirror 42 is for reflecting the light beam from the light emitting element f-22 and changing the optical axis of the destination.

In FIG. 1(A), the optical axes of the incident light beam LA and the emitted light beam LB coincide. However, when the vehicle on the light transmitting side curves and the light beam LA becomes the light beam LA', the optical axes of the light beam LA' and the light beam LB no longer match.

At this time, the amount of light received by the light receiving element 40 is greater than the amount of light received by the light receiving element 38, and the rotating body 26 is rotated clockwise so that the amount of light received by the light receiving element 38 and the amount of light received by the light receiving element 40 match. Then, as shown in FIG. 2, the incident light beam L
The optical axes of A' and synchrotron radiation beam LB' coincide, resulting in an optimal transmission/reception state. If the optical axis is controlled to follow in this way, even if the vehicle on the transmitting side or the receiving side curves, as shown in Fig. 8 (
As shown in C), optical communication can be performed continuously without interruption.

Note that the light emitting element 22 and the convex lens 24 may be incorporated into the rotating body 26 without providing the plane mirror 42. Alternatively, the housing 12 may be pivoted so that the rotating body can rotate around an axis perpendicular to the axis 30, so that it can cope with pitching and rolling of the vehicle.

Next, the optical communication device will be explained according to FIG.

The audio signal input through the microphone 50 is digitized and stored in the transmitting/receiving circuit 52. Further, the ID code is inputted from the ID code input switch 53 to the transmitting/receiving circuit 52. The transmitter/receiver circuit 52 modulates this ID code and the time-base compressed audio signal.

The light emitting element 22 converts it into an optical signal and transmits it to the other party's light transmitter/receiver.

A aiming light beam LA is sent from the other party to the light receiving elements 36, 38, and 40. The output signals of the light receiving elements 38 and 400 are respectively amplified by amplifiers 54 and 56 and supplied to a differential amplifier (servo amplifier) 58, and a signal corresponding to the difference in the amount of light received by the light receiving elements 38 and 40 is output by the differential amplifier. 58 and is supplied to an amplifier 64 via a C contact 62 of a relay 60. The amplifier 64 amplifies this power and supplies it to the DC motor 32, so that the DC motor 32 rotates so that the amounts of light received by the light receiving elements 38 and 40 are equal. As a result, the rotating body 26 rotates around the shaft 30, and the optical axis of light transmission and the optical axis of light reception coincide.

The rotation angle of the DC motor 32 is detected by a bridge circuit 66 incorporating a potentiometer 34. After the unbalanced voltage of the bridge circuit 66 is amplified by the amplifier 68,
C contact 62. The signal is supplied to the DC motor 32 via an amplifier 64. As shown in FIG. 1(A), the unbalanced voltage of the bridge circuit 66 becomes O when the rotating body 26 is in the neutral position.

Therefore, when the C contact 62 is switched to the normal oven side, the DC motor 32 rotates and the rotating body 26 is placed in the neutral position. As a result, even if the optical axis directions of the light beams L and LA'' are inclined in either the left or right direction from the axial direction of the rotating body 26 in the neutral position, the angular difference becomes small, and the light receiving elements 38 and 40 The direction of the optical axis can be detected without fail, and the optical axes of transmitting and receiving light can be quickly aligned.

The ID code signal and audio signal sent from the other party are received by the light receiving element 36, amplified by the amplifier 70, and supplied to the transmitting/receiving circuit 52. The transmitter/receiver circuit 52 temporarily stores the audio signal, expands the time axis, and sends the audio signal to the speaker 71.
and play the audio.

Further, the output signal of the amplifier 70 is also supplied to a comparator 72, and when reception is interrupted, an optical reception termination signal STP is supplied from the comparator 72 to an optical reception termination determination circuit 74. In addition, the optical reception discontinuation determination circuit 74 includes a transmitting/receiving circuit 5
2, a voice input start signal SS, a voice input end signal SE, and a clock signal CP used for timing of the transmitting/receiving circuit 52 are supplied. 1L discrimination circuit 74 during optical reception
determines from these input signals that optical reception has been discontinued, and supplies pulses of a constant width to the amplifier 76.

The amplifier 76 amplifies the power of this, excites the relay coil 78, and switches the C contact 62 to the normal oven side.

As a result, the rotating body 26 becomes in a neutral position and can prepare for the fourth transmission and reception.

FIG. 4 shows details of the 1L determining circuit 74 during optical reception, which will be explained according to the time chart 1 shown in FIG.

Time T1 from when the voice input start signal SS is input until the voice input end signal SE is input when inputting voice from the microphone 50 to the transmitting/receiving circuit, RS flip-flop circuit 80
A high-level signal is output from the gate and supplied to the AND gate 82. During this time T1, the clock signal CP is supplied to the counter 86 via the AND gate 82° and the OR gate 84. The counter 86 is cleared by the audio input start signal SS. Therefore, the value of the counter 86 is counted by the counter 86 in proportion to the T□ time.

In this embodiment, the counter 86 is composed of 4 bits, and the value of each bit is stored in the D flip-flop circuits 90.92, 94.96 at the timing of the audio input end signal SH.

After the time T1 has elapsed, the audio signal is compressed in time and transmitted from the light emitting element 22 to the vehicle ahead. Between this time T and T2, the aiming light beam is incident on the light receiving element 36. When this input is interrupted, the optical reception cutoff signal STP becomes low level, is inputted to the inverter 98, inverted, and then inputted to the AND gate 102. This causes the clock signal CP to be applied to the AND gate 102. It is supplied to a counter 86 via an OR gate 84 and counted. Further, the optical reception disconnection signal STP inverted by the inverter 98 is input to the timer 100, and is inputted to the timer 100 for a certain period of time T3.
Afterwards, one pulse is output from the timer 100 and is supplied to the counter 86 via the OR gate 88, so that the counter 86 is cleared.

Therefore, the value of the counter 86 becomes a number proportional to the time after T3 has elapsed.

When time T1 elapses from time T3, the value of each bit of counter 86 changes to flip-flop circuits 90, 92, 94, .
96, and the output signals of exclusive OR gates 104, 106, 108, and 110 become low level. These signals are then supplied to the NOR gate 112, and the NOR gate 112 outputs an output signal S3, which is then supplied to the AND gate 114. At this time, if the optical reception disconnection signal STP is at a high level, the AND gate 114
is opened, and the output signal S3 is sent to the mono multivibrator 11.
6, a constant width pulse is supplied from the mono-multivibrator 116 to the amplifier 76 shown in FIG. 3, and the relay coil 78 is excited.

Therefore, if the time T4 at which the light beam incident on the light receiving element 36 is interrupted is greater than the sum of the audio input time T1 and the time T3 set by the timer 100, that is, T,>T
, +T3, the DC motor 32 rotates and the rotating body 26
becomes the neutral position and prepares for the next light reception. In addition, in the case of T4 + T1 + T3, the AND gate 114 is closed, so the signal S3 is transmitted to the mono multivibrator 116.
The relay coil 78 remains demagnetized. In other words, transmission and reception will continue.

Note that, without considering T1, it may be determined that optical communication has been discontinued if T4 is greater than a certain period of time.Also, the configuration in which the rotating body 26 is placed in the neutral position is such that the inner end of the mainspring is fixed to the shaft 30, and the outer end is attached to the housing 14.
It may be fixed to the neutral position and mechanically returned to the neutral position.

Next, the operation of this embodiment configured as described above will be explained with reference to the flowcharts shown in FIGS. 6 and 7.

In FIG. 8(C), a case will be described in which the signal is transmitted from the vehicle CB side to the vehicle CA side and the vehicle CA side receives it. Furthermore, in the optical communication device shown in FIG.
The description will be given with A added to the part number for the one on the side of the vehicle, and B added to the part number for the one on the vehicle CB side.

In step 200, an audio signal is input to the transmitter/receiver circuit 52B via the microphone 50B and is stored. At the start of this input, a voice input start signal SS is supplied to the optical reception stop determination circuit 74, and at the end of the input, a voice input end signal SE is supplied to the optical reception stop determination circuit 74.Next, the process advances to step 202, and the ID code input switch is 5
The transmitting/receiving circuit 52B transmits the In code set by 3B to the light receiving element 36A side via the light emitting element 22B.

In FIG. 7, on the vehicle CA side, in step 300, I
Wait for the D code to be received and proceed to step 302.The received ID code is input to the ID code input switch 53A.
If the ID code matches the ID code set in step 304, the ID code is transmitted to the light receiving element 36B and a aiming light beam is sent out.

On the vehicle CB side, in step 204 shown in FIG. 6, the ID code sent from the vehicle CA side is set by the ID code input switch 53B, and the process proceeds to step 206 after waiting for the aiming light beam to be received. ID
If it matches the code, the process proceeds to step 208, where it is determined whether the received light level is above a certain value.

If the optical axes of the light transmission and reception coincide, the light reception level becomes a constant value, and the process proceeds to step 210, where the audio signal stored in the transmission/reception circuit 52B is compressed in time and transmitted from the light emitting element 22B to the light receiving element 26A. . As a result, vehicle CB
Transmission of the audio signal from the side to the vehicle CA side ends.

Note that an audio start signal and an audio end signal are added before and after the audio signal starts and ends, respectively.

On the vehicle CA side, at step 306 in FIG. 7, the vehicle CA waits until the voice start signal is received, and proceeds to step 308 to receive the voice signal. This audio signal is transmitted to the light receiving element 3.
6A, the signal is temporarily stored in the transmitting/receiving circuit 52A via the amplifier 70A, and the process proceeds to step 310, where the time axis of this audio signal is expanded and audio is output from the speaker 71. This completes the process of receiving the audio signal and reproducing the audio on the vehicle CA side.

[Effects of the Invention] The control device for optical communication between moving objects according to the present invention is provided on a rotating body that rotates the direction of the optical axis of transmitted light, and is arranged at a distance at a position where the received light is focused and incident. Feedback control of the rotation angle of the rotating body so that the difference between the detection signals from the first light receiving element and the second light receiving element, the driving means for rotationally driving the rotating body, and the first light receiving element and the second light receiving element becomes zero. Since the optical axis direction of the transmitted light coincides with the optical axis direction of the received light, the moving body performing optical communication is prevented from curving, pitching, rolling, etc. Even if the optical communication occurs and progresses, it is possible to perform optical communication without interruption, and it has the excellent effect that optical communication can be performed for a long time.

[Brief explanation of the drawing]

FIG. 1(A) is a cross-sectional view of a light transmitter/receiver according to an embodiment of the present invention, FIG. 1(B) is a side view of FIG. 1(A), and FIG. 2 is an optical axis for transmitting and receiving light. 3 is a block diagram of the optical communication device, and FIG. 4 is a circuit showing an example of the first reception A8 cancellation determination circuit 74 shown in FIG. 3. Fig. 5 is a time chart for explaining Fig. 4, Fig. 6 is a schematic flow chart of transmission, Fig. 7 is a schematic flow chart of reception, and Figs. 8 (A) and (B) are explanatory diagrams of the conventional example. , FIG. 8(C) is an explanatory diagram showing a state yE in which optical communication is performed between vehicles in this embodiment. 16II1111 filter, 181 concave mirror, 22...light emitting element, 26.participant rotating body, 28 fist e arm, 36.38.40...ψ light receiving element, 42...fist plane mirror.

Claims (1)

[Claims] A first light-receiving element and a second light-receiving element provided on a rotating body that rotates the optical axis direction of transmitted light and spaced apart from each other at a position where the received light is focused and incident, and a drive that rotationally drives the rotating body. and an optical axis direction control means for feedback controlling the rotation angle of the rotating body so that the difference between the detection signals from the first light receiving element and the second light receiving element becomes zero, and the optical axis direction of the transmitted light is set so that the optical axis direction of the transmitted light is set to the direction of the received light. 1. A control device for optical communication between moving bodies, characterized in that the optical axis direction of the optical communication device coincides with the direction of the optical axis of the optical communication device.