JP2758834B2 - Passage measurement device for each vehicle in automobile race etc. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring the passage of vehicles such as automobile races and motorbike races.
The present invention relates to an optical transmission / reception type vehicle-by-vehicle passage measurement device.

[0002]

2. Description of the Related Art As an apparatus for measuring the passage (rank etc.) of each vehicle in an automobile race or the like, an unmanned measurement apparatus for an automobile race or the like disclosed in Japanese Utility Model Laid-Open Publication No. 3-47680 is known. This unmanned measurement device is equipped with a beam oscillator having a beam oscillation unit and a vehicle-specific code setting unit that sets a different bit code for each vehicle in an appropriate place of the vehicle, and on the traveling road side,
A photoelectric detector that receives a light beam oscillated from the light beam oscillator of the passing vehicle and converts it into an electric signal, and a passing vehicle identifier that processes the signal from the photoelectric detector and determines the vehicle corresponding to the vehicle-specific code. It is provided.

[0003] Since the light beam including the vehicle-specific code continuously oscillates from the light beam oscillating section of the vehicle during traveling, when the vehicle crosses the vicinity of the photoelectric detector installed on the side of the traveling path, the light beam is immediately emitted. Light from a vehicle light oscillator is received by an optoelectronic detector. The photoelectric detector converts the light beam into an electric signal and sends it to the passing vehicle identifier. In the passing vehicle identifier, the vehicle-specific code included in the signal is electrically identified, and the passing vehicle can be identified. It has become.
For this reason, it is possible to unmanned until the determination of the passing order and the lap time, etc., irrespective of the vehicle body color, the size of the vehicle, the weather conditions such as fog and fog, and the lightness conditions such as day and night. It is possible to accurately determine the lap order of a large number of vehicles.

[0004]

However, the above-mentioned conventional unmanned measuring apparatus has the following problems.

[0005] Different bit codes (pulse width modulation (PW) of a combination of short wavelength pulses and long wavelength pulses) for each vehicle
M)) is always oscillated during traveling. However, in the photoelectric detector on the traveling road side, since the light receiving intensity and the like differ depending on the distance to the traveling vehicle, an automatic gain control (AGC) circuit for preventing waveform distortion is provided on the passing vehicle discriminator side. It is necessary to oscillate a preamble part (confirmation pulse) for automatic gain control prior to the bit code in order to reliably recognize the start bit of the bit code corresponding to the above.

However, the transmission period of the preamble portion is a time necessary for the AGC circuit to be stable in consideration of all spatial relationships such as directivity and distance between the traveling vehicle and the photoelectric detector on the traveling road. In addition to this, the bit code transmission time also increases with the number of vehicles as the number of vehicles increases, so that the transmission period (one oscillation cycle) of the frame data composed of the preamble portion and the bit code is necessarily long. There was a problem. For example, 200k / h
In the case of traveling m, the time required for traveling 1 m is 18 ms.
ms, and it is necessary to transmit the frame data two or more times within this time to check for erroneous reception. However, since the frame data is too long, it is actually limited to one transmission. It is a fact that bit collation for a malfunction check is impossible, and the reliability of rank determination is lacking. For example, when light is received by the photoelectric detector on the side of the traveling road from the middle of the frame data, the entire bit code cannot be received, and there is a possibility that a missing order of passing vehicles may be missed.

In the above prior art, only the photoelectric detector (optical receiver) needs to be provided on the traveling road side, and only the light beam oscillating unit (optical transmitter) needs to be mounted on the traveling vehicle side. Although it has the advantage of requiring only a directional optical transceiver, the traveling vehicle needs to continuously oscillate the light beam including the bit code at a predetermined period, so that the power consumed for continuous light emission is continuously lost during the traveling period. As a result, the on-vehicle battery is consumed.

[0008] In view of the above problems, it is an object of the present invention to perform bit collation for checking error reception when a vehicle passes on the traveling road side, thereby improving the reliability of ranking determination, and reducing the consumption on the traveling vehicle side. An object of the present invention is to provide a vehicle-by-vehicle passage measurement device capable of reducing electric power, such as an automobile race.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a vehicle-by-vehicle passage measurement apparatus for an automobile race or the like, which is equipped with a traveling roadside device as an interrogator installed on the traveling roadside for each vehicle. And a vehicle-side device, which is a transponder, and employs a pulse phase modulation type optical communication in a two-way communication system. That is, the traveling roadside device is a light oscillating unit that repeats interrogation pulse emission at a predetermined cycle, and receives a response pulse light beam from the vehicle side device, and determines a time between the time of the interrogation pulse emission and the time of receiving the response pulse emission. It comprises a light receiving means for measuring a time difference, and a passing vehicle identification means for determining a passing vehicle based on the time difference. On the other hand, the vehicle-side device is a light receiving unit that receives the interrogation pulse beam from the traveling road-side device, and a response light-emitting unit that emits the response pulse after a vehicle-specific time difference from the time of receiving the interrogation pulse emission. And a vehicle-specific response time difference setting means for setting the vehicle-specific time difference of the response light emitting means.

Here, it is desirable to adopt the following configuration in order to reliably identify the interrogation pulse and the response pulse. That is, in the present invention, the light oscillating means of the traveling roadside device has continuous pulse generating means for generating an interrogation pulse composed of at least two consecutive pulses at a first time interval, and The light receiving means of the apparatus has a response pulse interval detecting means for detecting whether or not a response pulse composed of at least two consecutive pulses is received at a second time interval. The receiving means has an interrogation pulse interval detecting means for detecting the presence or absence of reception of an interrogation pulse composed of at least two consecutive pulses at a first time interval, and the response light emitting means of the vehicle-side device, It has a continuous pulse generating means for generating a response pulse composed of at least two consecutive pulses at a second time interval.

Further, in the present invention, the light receiving means of the roadside device has a response pulse width detecting means, and the light receiving means of the vehicle side device has an interrogating pulse width detecting means. Is desirable. And, in general, the first time interval and the second time interval are equal.

[0012]

The light oscillating means of the traveling roadside device repeats intermittent pulse emission at a predetermined cycle. Therefore, the light receiving means of the vehicle passing through the sensing area is irradiated with the light of the interrogation pulse, so that the light receiving means receives the interrogation light, and the response light emitting means emits the interrogation light in response to this. The response pulse is emitted after the vehicle-specific time difference from the light receiving time point. The vehicle-specific time difference is a vehicle-specific code by the vehicle-specific response time difference setting means. When the response light emission is received by the light receiving means of the traveling roadside apparatus, the time difference between the time of the interrogation pulse light emission and the time of the reception of the response pulse light emission is measured, and the passing vehicle identification means determines the passing vehicle based on the time difference. As described above, the present invention employs the traveling-path-side device serving as an interrogator and the vehicle-side device serving as a transponder, and employs bidirectional pulse phase modulation type optical communication.
Even if different response time differences are assigned to a large number of vehicles for each vehicle, one response time can be shortened, so that the number of bidirectional communication within the sense area becomes plural, and the reliability of ranking determination by bit comparison is improved. be able to. Furthermore, the vehicle-side device emits a response light only when an interrogation light emission pulse is received in the sense area for each turn, and remains off in the outside of the sense area. Therefore, the power consumption of the vehicle-side device can be significantly reduced as compared with the related art, and the consumption of the mounted battery can be suppressed.

Here, when the interrogation pulse is formed from at least two consecutive pulses at a first time interval and the response pulse is formed from at least two consecutive pulses at a second time interval, the continuous pulse By employing the generating means and the pulse interval detecting means, it is possible to easily and quickly determine whether the pulse is an inquiry pulse or a response pulse. From this point,
(1) It contributes to shortening of the response time.

Further, according to the configuration in which the roadside device and the vehicle-side device are provided with the pulse width detection means, even if the pulse interval detection means mistakenly recognizes two consecutive noises as an inquiry pulse and a response pulse, Since the noise does not have a pulse width, the pulse width detecting means can identify the noise, so that an erroneous recognition operation can be effectively prevented.

If the first time interval is different from the second time interval, it is possible to prevent the risk that the reflected light of the interrogation pulse light enters the light receiving means of the roadside apparatus and malfunctions.
In order to simplify the device configuration and reduce the cost, the first time interval and the second time interval can be made equal.

[0016]

Next, an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a block diagram conceptually showing a vehicle-by-vehicle passage measurement apparatus for an automobile race or the like according to an embodiment of the present invention. The vehicle-specific passage measurement device 100 of this example is a bidirectional optical communication system that employs pulse phase modulation or pulse position modulation (PPM) that modulates the phase of a pulse. And a transponder-side device 20 mounted for each competitive vehicle such as an automobile race orbiting the traveling route.

The traveling roadside device 10 comprises one or more optical oscillators 32 for repeatedly emitting interrogation pulses and an optical receiver 34 for receiving a response pulse beam and detecting a time difference (pulse phase) between the response pulse and the interrogation pulse. Optical transmission / reception units 30 (1) to (n), an oscillating circuit 40 for determining an oscillation cycle of interrogation pulse emission of the optical oscillator 32, and a passing vehicle identification for determining a passing vehicle based on a time difference between an inquiry pulse and a response pulse. And a part 50.

The vehicle-side device 20 is provided with an optical receiver 60 that receives the light of the interrogation pulse from the optical oscillator 32 of the traveling road-side device 10 and converts the light into an electric signal. Response light emitting device 70 that emits light after response
And a response time difference setting unit 80 for setting a different time difference for each vehicle of the response light emitter 70, and an oscillation circuit 90 for supplying a required oscillation signal to the optical receiver 60 and the response light emitter 70. .

As shown in FIG. 2, the plurality of optical transmission / reception units 30 are arranged side by side at a distance W1 directly below a gate 95 provided at the goal of the racetrack. The sense area angle of the optical oscillator 32 of the optical transmitting and receiving unit 30 in the width direction of the traveling road is α, and the width W2 of the sensing area on the traveling road surface is wider than the width W3 of the traveling vehicle 96. The sense areas of the adjacent optical transmission / reception units 30 and 30 share a cross area (hatched portion in the drawing).
Therefore, any part of the width of the goal is included in the sense area of one of the optical oscillators 32 of the optical transmission / reception unit 30 side by side.

As shown in FIG. 3, the sense area angle of the optical oscillator 32 of the optical transmitting and receiving unit 30 in the traveling direction is β.
In this example, the optical receiver 60 of the vehicle-side device 20 mounted on the vehicle 96 always passes through the sensing area of 2 m or more.

FIG. 4 shows a detailed configuration of the traveling roadside device 10. In this figure, the oscillation circuit 40 has a frequency of 456 KHz.
A main oscillator (self-excited oscillator) 41 including a crystal oscillator that oscillates a source oscillation clock pulse CL having a period of 2.2 μs;
The source oscillation clock pulse CL is divided by 1/12 to a frequency of 38 KHz (period 26.4 μs) and a duty ratio of 50%.
And a 1/12 frequency dividing circuit 42 for generating an oscillation pulse OS, and counting the oscillation pulse OS up to a count-up value of 380, at a frequency of 100 Hz (cycle of 10 ms) and a duty ratio of 2/3.
A question timing circuit 43 of a 10 ms retrigger counter for generating 80 question timing pulses QT and a phase measurement clock pulse CP for measuring the response time difference (pulse phase) by dividing the oscillation pulse OS by 1/2.分 frequency dividing circuit 44 which performs a logical AND operation of the oscillation pulse OS and the interrogation timing pulse QT to generate two consecutive oscillation pulses OS
And an AND gate 45 for producing an interrogation pulse Q composed of

The plurality of optical oscillators 32 (1) to 32 (32)
(N) is a current amplifier 32a that current-amplifies the pulse signal of the interrogation pulse Q, and emits light by generating the interrogation pulse Q and emits narrowband infrared interrogation pulse light having a peak at a wavelength of 940 nm into the sense area. A light emitting element 32b such as a diode. The oscillation circuit 40 and the optical oscillator 32 constitute an optical transmitter that modulates infrared light with an oscillation pulse OS.

The optical receiver 34 (1) of the traveling roadside apparatus 10
34 (n) is a response light emitter 70 of the vehicle-side device 20.
A light receiving element 34a such as a phototransistor that receives infrared pulsed light emitted in response to light and converts it into an electric signal, a buffer amplifier 34b that amplifies the electric signal, and a Schmitt trigger that shapes the input waveform of the response signal into a square wave A waveform shaper 34c of a type comparator, a response pulse detection circuit 34d of a logic filter for detecting a normal response pulse included in the input signal A, and a detection pulse D of the response pulse A which is set by the interrogation timing pulse QT.
A response time difference determination circuit 34e of the RS flip-flop reset by T, and a time difference measurement circuit 34f that detects the response time difference by counting the phase measurement clock pulse CP reset by the output Q5 of the response time difference determination circuit 34e.
And

The passing vehicle identification unit 50 receives the output Q5 from each response time difference determination circuit 34e as an interrupt signal, a multi-input OR gate 51, and receives the interrupt signal from the chip selector 52 when the interrupt signal is input. , A count value corresponding to the time difference is read from the time difference measurement circuit 34f, and a rank determination process for identifying a passing vehicle and a lap time process are executed from the read value. It has a microcomputer (CPU) 53 and a host computer 54 connected to the microcomputer 53 via a transmission line 54a.

Each of the response pulse detection circuits 34d and an inquiry pulse detection circuit 64, which will be described later, have the same configuration, and as shown in FIG. a D-type flip-flop 34da the Q output is inverted, one which has a capacitor C ₁ and resistor R _1, to produce a one shot pulse having a pulse width of a predetermined time constant rise in the wake of the response pulse (interrogation pulse) Shot multi vibrator 34db
And a pulse shaping circuit 34dc for generating a negative reset pulse RS with a narrow pulse width in synchronization with the fall of the pulse, and a Q output Q of a D-type flip-flop 34da.
A logical AND gate 34de for calculating the logical AND of the source clock pulse CL of 1 and 456 KHz, and a logical AND gate 34d for calculating the logical AND of the input pulse A and the main clock pulse CL.
f, a pulse interval measuring counter 34dg for counting output pulses of the AND gate 34de, a pulse width measuring counter 34dh for counting output pulses of the AND gate 34df, and a pulse interval measuring counter 34dg.
The pulse interval suitability determination circuit 34di which determines whether or not the count value of the counter has reached the permissible values 11 to 13 and whether or not the count value of the pulse width measurement counter 34dh has reached the permissible values 3 to 9 The pulse width suitability judging circuit 34dj, and the pulse interval suitability judging circuit 34di and the pulse width suitability judging circuit 34dj, which are determined by comparing the above, send out the adaptation signal and when the second response pulse (interrogation pulse) arrives. AND gate 34dk for generating a detection pulse DT of a response pulse (interrogation pulse).

[0027] The pulse shaping circuit 34dc includes an integrating circuit S consisting of D-type resistance to blunt waveform of the Q output Q2 of the flip-flop 34Da R ₂ and capacitor C _2, Q of the integrated signal and the D-type flip-flop 34db (Bar) A NAND gate G that receives the output Q3 as an input and outputs a reset pulse RS. In addition,
The reset pulse RS is supplied to the D-type flip-flop 34da, the counters 34dg and 34dh, the suitability determination circuit 34di,
34dj is supplied to the reset terminal of a PLD (programmable logic device).

On the other hand, the optical receiver 60 of the vehicle-side device 20
As shown in FIG. 6, a light receiving element 61 such as a phototransistor for receiving the infrared light emitted by the interrogation pulse from the optical oscillator 32 of the traveling roadside device 10 and converting the infrared light into an electric signal, a buffer amplifier 62 for amplifying the electric signal, A waveform shaper 63 of a Schmitt trigger type comparator for shaping the input waveform of the interrogation signal into a square wave, and an interrogation pulse detection circuit 64 for detecting a normal interrogation pulse included in the input signal A and outputting a detection pulse DT. Have. This interrogation pulse detection circuit 64 has the same configuration as the response pulse detection circuit 34d shown in FIG. 5, and detects whether or not an incoming pulse is an interrogation pulse.

The oscillating circuit 90 of the vehicle-side device 20 has the same configuration as the oscillating circuit 40 on the traveling road side and has a main oscillator 91 having a crystal oscillator for oscillating a source oscillation clock pulse CL of 456 KHz (period 2.2 μs). , The source oscillation clock pulse CL is divided by 1/12 to a frequency of 38 kHz (period 2).
A 1/12 frequency dividing circuit 92 for generating an oscillation pulse OS having a duty ratio of 50% in 6.4 μs), and reducing the oscillation pulse OS to １ ／
A 1/2 frequency dividing circuit 93 for generating a phase measuring clock pulse CP which is frequency-divided and serves as a time unit of a response time difference (pulse phase).

The response light emitter 70 of the vehicle-side device 20 includes an inverter 71 for inverting the polarity of the detection pulse DT from the interrogation pulse detection circuit 64, and a D-type flip-flop whose Q output is set by the inverted pulse (negative pulse). Step 72
And a load control pulse generating circuit 7 for generating a load control pulse LD having a narrow pulse width when the Q output rises.
3 and a cascade connection in which vehicle-specific time difference data (code data) set by the vehicle-specific response time difference setting section 80 is loaded and preset by receiving the load control pulse LD, and the phase measurement clock pulse CP is counted down.
Bit down counters 74a, 74b, and counter 74
AND gate 75 for determining the response emission timing by taking the logical product of both borrow signals M of a and 74b; AND gate 76 for generating a response pulse AP composed of a series of pulses;
A current amplifier 77 for current-amplifying the pulse signal of P; and a narrow-band infrared response pulse light emitted by generation of the response pulse AP and having a peak at a wavelength of 940 nm.
It has a light emitting element 78 such as a light emitting diode that irradiates 0, and a reset pulse generation circuit 79 that generates a reset pulse RS2 for resetting the D-type flip-flop 72 from the response pulse AP.

Here, the load control pulse generation circuit 73
An integrating circuit S consisting of D-type resistance to blunt Q (bar) output of the waveform of the flip-flop 72 R ₃ and capacitor C _3,
A NAND (NA) that outputs the load control pulse LD with the integration signal and the Q output of the D-type flip-flop 72 as inputs.
ND) gate G.

The reset pulse generating circuit 79 includes an inverter 79a for inverting the polarity of the response pulse AP, a D-type flip-flop 79b for inverting the Q output Q4 at the fall of the inverted pulse, and synchronization with the fall of the Q output Q4. And a pulse shaping circuit 79c for generating a reset pulse RS2 of negative polarity.

[0033] Then this pulse shaping circuit 79c is, the D-type to blunt waveform of the Q output Q4 of the flip-flop 79 and the resistor R ₄ and the integrating circuit S comprising a capacitor C _4, Q of the integrated signal and the D-type flip-flop 72 (Bar) NAND (NA) that outputs reset pulse RS2 with output as input
ND) gate G.

The vehicle-specific response time difference setting unit 80 includes setting switches SW1 and SW2 which can set the bit terminals A to D of the 4-bit down counters 74a and 74b to pull-down or pull-up connection, respectively. , 74b are selected.

Next, the operation of the vehicle-by-vehicle passage measuring apparatus according to the present embodiment will be described with reference to FIGS.

The main oscillator 41 of the roadside device 10 is shown in FIG.
As shown in FIG. 7, a source clock pulse CL of 456 KHz (period 2.2 μs) is oscillated, and a frequency of 38 KHz (period t = 26.4 μm) is output from the 1/12 frequency dividing circuit 42.
In s), an oscillation pulse OS having a duty ratio of 50% is generated. This oscillating pulse OS is output from the question timing circuit 43.
As shown in FIG. 7, an interrogation timing pulse QT having a period T = 10 ms including a high-level period of 2t and a low-level period of 378t is generated.

Then, every time the interrogation timing pulse QT is generated, the interrogation pulse emission is prompted. Oscillation pulse O
From the AND gate 45 which takes the logical product of S and the interrogation timing pulse QT to generate a group of interrogation pulses, as shown in FIG. Sent to The first (first) interrogation pulse is a pulse serving as a phase reference, and the second interrogation pulse is a pulse having a unique phase amount (t = 26.4 μs in this example) that means an interrogation pulse. . Therefore, the interrogation pulse light oscillates simultaneously from all the light emitting elements 32b connected in parallel, and as shown in FIG. 7, the interrogation pulse light emission QL of two consecutive times with a time difference t interval has a period T = 1.
The light is emitted into the sense area of the goal road surface every 0 ms.

Here, the interrogation pulse emission QL every 10 ms
Is repeated, it takes 36 ms for the vehicle to pass through the 2 m sense area at 200 km / h, so the number of times the query pulse is transmitted is 3.6 times. However, since the duty ratio of the interrogation timing pulse QT is 2t / 378t = 1/189, the number of transmissions of the interrogation pulse portion (2t) is definitely three times. Therefore, 3 bits necessary for bit matching (majority logic)
The number of times of transmission can be realized, and as described later, the reliability of determining the ranking of passing vehicles can be improved.

Next, when the light beam of the interrogation pulse light emission QL reaches the light receiving element 61 of the vehicle-side device 20 of the vehicle passing through the sense area, the output waveform of the buffer amplifier 62 becomes as shown in FIG.
As shown in the figure, two consecutive light receiving pulses AL have a period T = 10 m
Appears every s. The received pulse AL received by the optical receiver 60 is converted by the waveform shaper 6 of the Schmitt trigger type comparator.
3 is shaped into a square wave A shown in FIG. That is, in order to provide a hysteresis function and prevent chattering at the time of rising and falling, the Schmitt trigger type comparator has a binary value with a rising threshold (UTP: Upper Trip Point) in the rising process of the light receiving pulse QL in FIG. In the falling process of the light receiving pulse QL, the light is binarized by a lower rising threshold (LTP: Lower Trip Point).

Incidentally, the waveform of the light receiving pulse QL is distorted by noise such as extraneous light, and the pulse width changes in length, so that the duty ratio greatly changes from 50%. Q interval (period t = 2
6.4 μs), the interval between the light receiving pulses hardly changes. For this reason, in the vehicle-side device 20, the interrogation pulse detection circuit 64 having the same configuration as the response pulse detection circuit 34d on the traveling road side has two consecutive 26.4 μs intervals.
The emitted light receiving pulse is identified as an interrogation pulse, and when it is an interrogation pulse, the detection pulse DT is output in synchronization with the second light receiving pulse as follows.

First, the first light receiving pulse A (1) is applied to the D-type flip-flop 3 of the interrogation pulse detecting circuit 64 shown in FIG.
When applied to the 4 da clock input terminal CK, as shown in FIG. 9, the Q output Q1 of the D flip-flop 34da rises to a high level, and then the second light receiving pulse A (2) is applied to the D flip-flop. When applied to the 34 da clock input terminal CK, the Q output Q1 falls and goes low. Therefore, this D-type flip-flop 3
By measuring the high-level period of the 4-da Q output Q1, the presence or absence of the interrogation pulse can be detected. Q output Q1
In the high level period, the AND gate 34de opens, and FIG.
As shown by X, the source clock pulse CL is passed. In the high level period of the first light receiving pulse A (1), the AND gate 34df opens, and as shown in Y of FIG.
The source oscillation clock pulse CL is passed. Now, in FIG. 9, 12 consecutive source clock pulses appear on the output X of the AND gate 34de, and three consecutive source clock pulses appear on the output Y of the AND gate 34df. The output X of the AND gate 34de is counted by a pulse interval measuring counter 34dg, and the output Y of the AND gate 34df is calculated.
Is counted by the pulse width measurement counter 34dh. The count value of the pulse interval measurement counter 34dg is an allowable value 11
It is determined by the pulse interval appropriateness determination circuit 34di whether or not it is within the range of .about.13. Even when the interval (phase difference) between the light-receiving pulses A is normally t = 26.4 μs, when the light-receiving pulse A starts in the middle of the first source clock pulse CL,
In some cases, one source oscillation clock pulse is missing, and in some cases, the light receiving pulse interval is slightly deviated from t.
Rather, in this example it is 1 in order not to reject the regular interrogation pulse.
2 ± 1 is an allowable numerical value.

However, the D-type flip-flop 34
da is not only set by the light receiving pulse A of the interrogation pulse, but also performs a flip-flop operation if the output of the waveform shaper 63 contains a whisker-like noise. Therefore, when two noises accidentally enter the D-type flip-flop 34da at an interval t of about 26.4 μs, there is a possibility that a signal indicating conformity is output from the pulse interval appropriateness determination circuit 34di. In order to eliminate such an erroneous recognition, in this example, the AND gate 34df, the pulse width measurement counter 34dh, and the pulse width appropriateness determination circuit 3
4dj are provided. That is, if the light-receiving pulse is a mustache-like noise, the logical product gate 34df opens during the high-level period of the light-receiving pulse A in this example because the pulse does not have a high-level period, that is, the pulse width. As described above, the source clock pulse CL is passed, and the number of source clock pulses included in the high-level period of the light receiving pulse A is counted by the pulse width measurement counter 34dh, and the counted value is within the allowable numerical values 3 to 9. Whether the pulse width is appropriate or not is determined by the circuit 34d.
j is determined. If the noise is completely mustache, the count value of the pulse width measurement counter 34dh is zero.
Considering the occurrence of noise groups close to each other, the count value 1
Pulse widths of ~ 2 are suspicious. On the other hand, since the duty ratio of the interrogation pulse is originally 50% and the duty ratio of the light-receiving pulse without distortion is 50%, the pulse width should ideally be the count value 6. However, as described above, since waveform distortion occurs due to disturbance light or the like, values around the median value 6 should also be allowable values. Therefore, in this example, the allowable value is 6 ± 3. As described above, in this example, the appropriateness of the interval of the light receiving pulse and the appropriateness of the pulse width
The presence / absence of an interrogation pulse is detected by the heavy decimation means, and when the presence / absence of an interrogation pulse is determined, FIG.
As shown in the figure, the detection pulse D is output from the AND gate 34dk.
T is output in synchronization with the second light receiving pulse.

When the light receiving pulse A arrives and is applied to the B terminal of the one-shot multivibrator 34db,
This one-shot multivibrator 34db has a resistor R
₁ and a time constant determined by the capacitor C ₁ (for example, 53 μm).
The Q output Q2 having the pulse width of s) is transmitted. Therefore, after the arrival of the second light receiving pulse A (2), the Q output Q
2 falls and the Q (bar) output Q3 rises. Since the Q output Q2 is integrated by the integration circuit S to exhibit waveform dullness and is applied to one input of the NAND gate 34dc, the reset pulse RS rises in synchronization with the fall of the Q output Q2 as shown in FIG. After the fall, the reset pulse RS rises again. In order to prevent malfunction due to noise, the D-type flip-flop and counters 34dg, 34dh,
Judgment circuits 34di, 34dj and AND gate 34dk
PLD (programmable logic device) is reset.

As described above, the arrival of the normal interrogation pulse is confirmed by the interrogation pulse detection circuit 64 and the detection pulse D
When T occurs, the Q output q of the D flip-flop 72 rises as shown in FIG. 8 by the negative pulse inverted by the inverter 71. When the Q output q rises, the load control pulse generation circuit 73 outputs the reset pulse formation circuit 3 in the interrogation pulse detection circuit 64 described above.
Like the operation of 4dc, for generating a load control pulse LD, the set when t ₀ switch SW1, set preset value SW2 (vehicle-specific code data) is being preset loaded down counter 74a, to 74b You. In this example, 4-bit down counters 74a, 74
Since b is cascade-connected to form an 8-bit down counter, 2 ⁸ = 256 vehicle codes can be set, and 256 vehicles can be identified. The 4-bit down counters 74a and 74b decrement the preset value by one each time the phase timing pulse CP is applied. For example, when the preset value is 4, as shown in FIG. 8, the count value N increases from 4 to 3 to 2 every time the pulse CP is generated.
→ 1 Finally, the count value N of the 8-bit down counter becomes 0 when the fourth pulse CP arrives. The period in which the count value is zero (the period before the count value becomes 255) is 4
A borrow signal M is generated from both of the bit down counters 74a and 74b, and a response light emission timing pulse AT is generated from the AND gate 75. The pulse width of the response light emission timing pulse AT is one cycle of the clock pulse CP (= 2
Since t), a response light emission pulse AP of two consecutive oscillation pulses OS is generated from the AND gate 76, and the pulse signal is current-amplified by the current amplifier 77 and then travels from the light-emitting element 78 such as a light-emitting diode. Two consecutive response light emission pulses AP of infrared rays are emitted toward the transmission / reception unit 30 of the roadside device 10.

Note that the response light emission pulse AP is output from the inverter 7
The Q output of the D-type flip-flop as the pulse generation circuit 79b is set to Q4 by the pulse passing through 9a. That is, the Q output Q4 rises at the fall of the first response light emission pulse AP, and the Q output Q4 falls at the fall of the second response light emission pulse AP. Then, similarly to the operation of the reset pulse forming circuit 34dc in the interrogation pulse detection circuit 64, a negative reset pulse RS2 is generated when the Q output Q4 falls, thereby resetting the D-type flip-flop 72. , D-type flip-flop 79 at the fall of its Q output Q4.
b is reset.

As described above, the vehicle-side device 20 responds to the vehicle-specific code data from the time when the interrogation light emission pulse composed of two consecutive pulses is received (substantially the same time as the light emission time of the traveling road-side device 10). Time difference (Phase timing pulse CP
After that, two consecutive response light emissions at the interval t are completed. Note that the interval between the response light emission pulses may be different from the interval between the inquiry light emission pulses.

In the roadside device 10, the response time difference determination circuit 3 is activated by the falling edge of the interrogation timing pulse QT.
4e, the output Q of the RS flip-flop for the flag
5 is set. This set state means that transmission of two consecutive intermittent light emission pulses has been completed.
The time difference measurement circuit 34f by the rise of the output Q5
The up counter of (1) is reset. Here, assuming that the response light emission pulse AP arrives at the light receiving element 34a (1) among the light receiving elements 34a (1) to (n), the electric signal is amplified by the buffer amplifier 34b (1), and the Schmitt trigger type comparator is used. The rectangular light receiving pulse A shown in FIG. 10 is output from the waveform shaper 34c (1). As in the case of the interrogation pulse detection circuit 64 of the vehicle-side device 20, the detection pulse DT is output by the response pulse detection circuit 34d (1) in synchronization with the second light reception pulse. When the detection pulse DT of the response pulse is generated, the response time difference determination circuit 34e (1) returns to the reset state. Accordingly, the high level period of the output Q5 of the response time difference determination circuit 34e (1) corresponds to the response time difference of the response pulse from the vehicle. In the high-level period of the output Q5, the phase-measuring pulse C
Since P is applied to the clock input CK of the time difference measurement circuit 34f (1), the count value CO continues to increase before the output Q5 falls. Here, assuming that response light is received from a vehicle whose vehicle-specific code data is “4”, the output Q
At the fall of 5, the count value CO is “4”. When the output Q5 falls, the multi-input OR gate 51
The microcomputer 53 jumps to a subroutine, shifts to the execution process, and executes the chip sector 52 to execute the time difference measurement circuit 34f which is the interrupt source.
In (1), a chip select signal is issued and selected, and the count value CO = 4 is read. This means that the optical receiver 34 (1) that has received the response light emission, the time when the interrupt signal is generated (vehicle passing time), and the vehicle-specific code of the passing vehicle are collected. As a result, calculation processing of the vehicle ranking, the passing time, the lap time, the lap time, and the like are performed.

Here, for example, if the light receiving element 34a (1) and the child 34a (2) receive the response light emission of the vehicle-specific code "4" at the same time, the microcomputer 53 sends an interrupt signal of a different interrupt source to the microcomputer 53. However, since the machine cycle of the microcomputer 53 is fast, the time difference measurement circuits 34f (1) and 34f
The respective count values are read from (2). If the two counts match, one is discarded. If the counts are different, it is treated as if a different vehicle has passed at the same time.
In the sense area of m, bidirectional transmission and reception of interrogation light emission and response light emission can be performed at least three times, and bit collation by majority logic can be performed. Therefore, once captured data may be discarded. When a large number of vehicles pass at the same time, a large number of transmission / reception units 3 shown in FIG.
Since the overlap area is present in the sense area, it is possible to capture without passing any of the vehicles.

As described above, in this embodiment, the bidirectional communication system including two consecutive interrogation light emission and two consecutive response light emission is adopted, and the response time difference from the interrogation light emission time to the response light emission time is determined by the vehicle-specific code. Is adopted. By detecting the time interval of the interrogation light emission and the time interval of the response light emission, the presence or absence of the interrogation light emission and the response light emission can be easily and instantaneously confirmed, so that the time allocated to the response time difference is long, so that a large number (for example, 256) Since different codes can be assigned to vehicles and the number of bi-directional communications can be made a plurality of times, the reliability of ranking determination can be improved. Furthermore, the vehicle-side device 20 emits a response light when an interrogation light-emitting pulse is received in the sense area for each turn, and remains off when it is outside the sense area. Therefore, the power consumption of the vehicle-side device 20 is significantly reduced as compared with the related art, and the consumption of an on-board battery that is important for the vehicle can be suppressed.

[0050]

As described above, the present invention relates to a traveling roadside device which is an interrogator installed on a traveling roadside and a transponder mounted for each vehicle in a vehicle-by-vehicle passage measuring device for an automobile race or the like. And a vehicle-side device, and is characterized in that pulse phase modulation type bidirectional optical communication is employed. Therefore, the following specific effects can be obtained.

Even if different response time differences are assigned to a large number of vehicles for each vehicle, one response time can be shortened, so that the number of two-way communication can be made a plurality of times.
As compared with the related art, it is possible to improve the reliability of the order determination by the bit comparison.

Furthermore, in the vehicle-side device, only when the interrogation light emission pulse is received in the sense area for each rotation,
It emits a response light, and remains off when it is out of the sense area. Therefore, the power consumption of the vehicle-side device can be significantly reduced as compared with the related art, and the consumption of the mounted battery can be suppressed.

By employing the continuous pulse generating means and the pulse interval detecting means, it is possible to easily and quickly determine whether the pulse is an inquiry pulse or a response pulse. This also contributes to shortening of one response time.

Further, according to the configuration in which the roadside device and the vehicle-side device are provided with the pulse width detecting means, even if the pulse interval detecting means erroneously recognizes two consecutive noises as the interrogation pulse and the response pulse, Since the noise does not have a pulse width, the pulse width detecting means can check the noise, so that the S / N ratio is improved and the erroneous recognition operation can be effectively prevented.

If the first time interval is different from the second time interval, it is possible to prevent a risk that the reflected light of the interrogation pulse light enters the light receiving means of the traveling roadside device and malfunctions. On the other hand, when the first time interval is equal to the second time interval, the device configuration can be simplified and the cost can be reduced by using common components.

[Brief description of the drawings]

FIG. 1 is a block diagram conceptually showing a vehicle-by-vehicle passage measurement apparatus for an automobile race or the like according to an embodiment of the present invention.

FIG. 2 is a front view showing a mounting mode of a plurality of optical transmission / reception units at a gate in the vehicle-specific passage measurement device.

FIG. 3 is a side view showing a mounting mode of the optical transmission / reception unit at a gate.

FIG. 4 is a block diagram illustrating a detailed configuration of a traveling roadside device in the vehicle-specific passage measurement device.

FIG. 5 is a block diagram showing details of a pulse detection circuit of the roadside device and the vehicle-side device in the vehicle-specific passage measurement device.

FIG. 6 is a block diagram showing a detailed configuration of a vehicle-side device in the passage measurement device for each vehicle.

FIG. 7 is a timing chart showing waveforms of various signals up to interrogation light emission in the traveling roadside device.

FIG. 8 is a timing chart showing waveforms of various signals in the vehicle-side device.

FIG. 9 is a timing chart showing waveforms of various signals in the interrogation pulse detection circuit of the vehicle-side device.

FIG. 10 is a timing chart showing waveforms of various signals from reception of a response light emission pulse to detection of a response time difference in the traveling roadside device.

[Explanation of symbols]

REFERENCE SIGNS LIST 100 pass-by-vehicle measuring device 10 road-side device (interrogator) 20 vehicle-side device (responder) 30 optical transmitter / receiver unit 32 optical oscillator 32a current amplifier 32b light emitting element 34 optical receiver 34a light receiving Element 34b Buffer amplifier 34c Waveform shaper 34d Response pulse detection circuit 34e Response time difference determination circuit 34f Time difference measurement circuit 34da D-type flip-flop 34db One-shot multivibrator 34dc Pulse formation circuit 34de, 34df Logical product Gate 34dg ... Pulse interval measurement counter 34dh ... Pulse width measurement counter 34di ... Pulse interval suitability determination circuit 34dj ... Pulse width suitability determination circuit 34dk ... Logic gate 40 ... Oscillation circuit 41 ... Main oscillator 42 ... 1/12 frequency dividing circuit 43 ... Question timing circuit 44 ... 1 Frequency dividing circuit 45: AND gate 50: Passing vehicle identification unit 51: Multiple input OR gate 52: Chip selector 53: Microcomputer (CPU) 54a: Transmission line 54: Host computer 60: Optical receiver 61: Light receiving element Reference numeral 62: Buffer amplifier 63: Waveform shaper 64: Interrogation pulse detection circuit 70: Response light emitter 71: Inverter 72: D-type flip-flop 73: Load control pulse generation circuit 74a, 74b: 4-bit down counter 75, 76: Logical product Gate 77: current amplifier 78: light emitting element 79: reset pulse generation circuit 79: a inverter 79b: D-type flip-flop 79c: pulse shaping circuit 80 ... vehicle-specific response time difference setting unit SW1, SW2 ... vehicle-specific time difference setting switch 90 ... oscillator 91 ... light-receiving element 92 ... 1/12 divider circuit 93 ... 1/2 divider circuit 95 ... gate 96 ... vehicle C _1, C ₂ , C ₃ , C ₄ ... capacitors R ₁ , R ₂ , R ₃ , R ₄ ... resistors S ... integration circuits G ... NAND gates

Claims (4)

(57) [Claims] 1. A vehicle in an automobile race or the like of a pulse phase modulation type optical two-way communication system comprising a traveling roadside device as an interrogator installed on the traveling roadside and a vehicle side device as a transponder mounted for each vehicle. In another passage measuring device, the traveling roadside device is a light oscillation means that repeats interrogation pulse emission at a predetermined cycle, a response pulse light from the vehicle-side device is received and the time of the interrogation pulse emission and the response pulse Light receiving means for measuring a time difference from a light receiving point of light emission,
The vehicle-side device further comprises: a light-receiving device that receives the interrogation light beam from the roadway-side device; and a light-receiving device that receives the interrogation light. An automobile race comprising: a response light emitting unit that emits the response pulse after a vehicle-specific time difference from a time point; and a vehicle-specific response time difference setting unit that sets the vehicle-specific time difference of the response light emitting unit. Passage measuring device for each vehicle. 2. The passage-by-vehicle measuring device according to claim 1, wherein the light oscillating means of the traveling roadside device transmits the interrogation pulse consisting of at least two consecutive pulses at a first time interval. A response pulse interval for detecting presence or absence of reception of the response pulse consisting of at least two consecutive pulses at a second time interval; Detecting means, wherein the light receiving means of the vehicle-side device includes interrogation pulse interval detecting means for detecting the presence or absence of reception of the interrogation pulse composed of at least two consecutive pulses at a first time interval. And the response light emitting means of the vehicle-side device includes a continuous pulse generation means for generating the response pulse consisting of at least two consecutive pulses at a second time interval. A passage measuring device for each vehicle in an automobile race or the like, characterized by having 3. The passage-by-vehicle measuring apparatus according to claim 2, wherein the light receiving means of the traveling roadside device has a response pulse width detecting means, and the light receiving means of the traveling roadside device has a response pulse width detecting means. The passage measuring device for each vehicle in an automobile race or the like, wherein the light receiving unit has an interrogation pulse width detecting unit. 4. The vehicle-by-vehicle passage measurement device in an automobile race or the like according to claim 2, wherein the first
And the second time interval is equal to each other.