JPH07202770A - Device for confirming passing of mobile body - Google Patents

Abstract

PURPOSE:To provide a device capable of accurately confirming a timing when each mobile body presses through a line set based on each mobile body. CONSTITUTION:This device is constituted of a mobile body 7 with a coil antenna generating an electromagnetic wave mounted thereon, a detecting antenna 3 provided in a running path, and a comparison antenna 4 provided in front of the running direction of the detection antenna. A phase of an induced current of the detection antenna by the electromagnetic wave generated from the coil antenna and a phase of an induced current of the comparison antenna are compared to detect a timing of an inverted phase. Furthermore, the device is provided with a transmission antenna 5, which sends a pulse for exciting the coil antenna periodically. A specific address is set to the mobile body 7 and an internal counter is counted on the reception of the pulse and when the count is coincident with the address, a pulsating exciting current flows to the coil antenna. A counter counted synchronously with the internal counter of the mobile body 7 is provided in the detection antenna and the count of the counter is read by reading a timing when the induced current of the detection antenna 3 is inverted from the induced current of the comparison antenna 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for individually identifying the passage timing of an object moving at high speed and the moving body that has passed therethrough, and more particularly to a device for measuring the lap time of each car in a circuit race. Can be used effectively.

[0002]

2. Description of the Related Art Conventionally, it has been difficult to measure the passage timing of a reference point while distinguishing a plurality of high-speed moving bodies such as a race car traveling on the same course. For example, it is possible to measure the lap time of a competitive car in a circuit race with human eyes and a stopwatch, but the error is very large.
The higher the performance of a car, the smaller the error is required, and it is necessary to be able to measure up to one thousandth of a second in Formula 1 races. Therefore, it has become common to measure electrically.

Therefore, the measurement currently being performed is, as shown in FIG. 10, a control line (measurement line) of the course.
A pair of transparent photoelectric switches are installed on the top, and the lap time is specified by measuring the timing when the car cuts off this control line. On the other hand, each car is equipped with a transmitter with a different frequency, and the coil antenna embedded in the road surface in front of the control line measures the frequency of the radio waves output from the car and identifies the car number. To do. Then, the lap time and the vehicle number are combined on the computer, and the lap time of each individual vehicle is displayed.

[0004]

However, in the conventional measurement, the photoelectric switch is used to detect the lap time measurement timing. Therefore, when a plurality of cars pass through the control line in front of or behind each other, There is a problem that an accurate lap time cannot be specified.
That is, as shown in FIG. 11, if the two cars pass the control line, the light-shielding state continues for the length of the car A on the light emitter side, so the nose of the car B on the light receiver side has passed. I can't catch the timing. Therefore, there is an inconvenience that only one lap time exists for two cars. Further, the frequencies for identifying the vehicle number are transmitted from two different channels, and two different frequencies are recognized. Which vehicle number should be given one lap time. There is a fatal defect that the machine side cannot distinguish it at all.

In this case, if both cars are processed as the same lap, the lap time of the car B is incorrect. For example, if the vehicle is traveling at a speed of 300 km per hour near the control line, it is possible to discriminate about 8 cm by measuring up to one thousandth of a second. When the nose of car B is close to the nose of car A, the error is small, but when the nose of car B is close to the tail of car A, there is a distance difference of about 5 m. If this is treated as the same time, the lap time of car B is Causes an error of about 0.05 seconds. In this case, even if the system can measure up to one thousandth of a second, it is only one twentieth of the reliability.

An object of the present invention is to solve the above-mentioned conventional problems, and to provide an apparatus capable of accurately confirming the timing at which a moving object passes through a line set as a reference for each solid. It is provided.

[0007]

In order to achieve the above object, the present invention provides a moving body equipped with a coil antenna for generating an electromagnetic wave, a detecting antenna provided on a traveling path of the moving body, and a detecting antenna of the detecting antenna. It is composed of a comparison antenna provided in the front in the traveling direction, compares the phases of the induced currents of the detection antenna and the comparison antenna due to the electromagnetic waves generated in the coil antenna, and detects the timing of these induced currents in opposite phase. Using.

In more detail, in addition to the detection antenna and the comparison antenna, a transmission antenna is further provided on the traveling path, and a pulse for exciting the coil antenna is periodically transmitted from the transmission antenna while moving. A unique address is set on the body, and when the pulse is received, the internal counter is advanced, and when the address value matches the pulse value, a pulsed exciting current is sent to the coil antenna, and the moving body on the side of the detection antenna. A means for reading the timing at which the induced currents of the detection antenna and the comparison antenna have opposite phases and at the same time reading the numerical value of the counter is used. Furthermore, in order to stabilize the level of the induced current,
As the detection antenna and the comparison antenna, a means for providing a load for impedance matching at the reflection point on the opposite side of the receiving end was used.

[0009]

[Operation] An induced current is generated in the detection antenna and the comparison antenna by the electromagnetic wave generated in the coil antenna,
The induced currents of the two become opposite phases only when the coil antenna is located between the two. The means of the present invention captures this timing to confirm the passage of the moving body. As a detailed operation, the mobile body cyclically receives radio waves transmitted from the transmission antenna, advances the count value of the internal counter by this, and excites the coil antenna when a unique address value is reached. On the other hand, on the side where the detection antenna and the comparison antenna are installed, only the timing at which an opposite-phase induced current is generated according to the position of the coil antenna is captured, and the counter value that advances the count value in synchronization with the counter Is read at that timing to perform the operation of determining the address. As a result, a series of operations of simultaneously measuring time and determining an address is performed. Further, it has a function of stabilizing the level of the induced current generated by means of providing an impedance matching load to the detection antenna and the comparison antenna.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a case where the present invention is applied to a lap time measuring system in an automobile circuit race, 1 is a road surface on a race track, and 2 is a control line. Reference numerals 3 to 5 denote antennas embedded in the road surface 1, reference numeral 3 denotes a detection antenna for being embedded on the control line 2, and a detection antenna for capturing the timing when the moving body passes through the control line 2; A reference antenna 5 embedded in the antenna for identifying the phase of the signal received by the detection antenna is a transmitting antenna for transmitting a constant signal to the moving body. An important requirement here is that the detection antenna 3 should be installed directly above the control line as much as possible, and the comparison antenna 4
Is to establish a positional relationship in front of the detection antenna 3, that is, a moving body passes through the detection antenna 3 and then passes through the comparison antenna 4. Reference numeral 6 denotes a centralized controller for controlling the signals of the antennas 3 to 5 and confirming the moving body. Reference numeral 7 denotes a moving body, which will be described as a car participating in a race in this embodiment.

First, the means for measuring the timing at which the vehicle 7 passes the control line 2 will be described. Figure 2
As shown in FIG. 3, the vehicle 7 is equipped with a coil antenna 8, and an alternating current is passed through the coil antenna 8 to generate an alternating magnetic field. Although the detection antenna 3 and the comparison antenna 4 form fields A, B, and C, when an alternating magnetic field is generated in the coil antenna 8 when the vehicle 7 is in the field A, the detection antenna 3 and the comparison antenna 4 are included.
Since it is induced by the AC magnetic field before this, the phases of the induced currents generated in both are in phase. When the vehicle 7 travels in the direction of the arrow and the center of the coil antenna 8 passes directly above the detection antenna 3 and an AC magnetic field is generated after entering the field B, the induced current generated in the detection antenna 3 and the comparison antenna are compared. 4 has an opposite phase to the induced current generated in No. 4. Subsequently, when the car 7 is still traveling and passing directly above the comparison antenna 4, the induced currents generated in the two antennas 3 and 4 are in the same phase as a result that they are opposite to those in the field A. Therefore, if electromagnetic waves are emitted from the coil antenna 8 in the field B in which the phases of the detection antenna 3 are opposite to each other when viewed from the comparison antenna 4 side, the timing at which the vehicle 7 passes the control line 2 can be surely recognized. Therefore, if the clock is read at this timing, the time when the vehicle passes through the control line 2 can be measured. For example, a new lap time can be easily calculated by subtracting the immediately preceding lap time from this time. In the present invention, since the timing is recognized by comparing the phases of the two induced currents, even if external noise is superposed, the phase difference is not affected and noise-resistant measurement is possible. In particular, in the case of an automobile equipped with an engine, high-voltage spark noise is radiated, and there are many malfunctions in current detection and voltage detection, but in the present embodiment, such a problem is eliminated. Further, since the voltage difference is not used as the detection parameter, the detection position accuracy is very high, and the response time required for the judgment is dramatically shortened.

FIG. 3 shows a circuit for extracting the anti-phase timing from the induced current generated between the detection antenna 3 and the comparison antenna 4. The induced currents generated in the detection antenna 3 and the comparison antenna 4 are amplified by separate amplifiers 5 and 6, respectively, and waveforms a and b are output. The waveforms a and b are input to the synchronous detection circuit 11, and the detection output waveform c is output according to the in-phase and anti-phase timings. This output is averaged in the smoothing circuit 12 to obtain the waveform d.
Then, the waveform d is input to the comparison circuit 13 and compared with the threshold value 14 calculated in advance to obtain the timing output of the waveform e. Therefore, by reading the clock at the down edge of the waveform e, it is possible to determine the time when the car has passed the detection antenna 3, that is, the control line 2.

In the above description, if the AC magnetic field is constantly generated in the coil antenna 8, the control line 2
Since the phase is reversed immediately above, the time can be measured very accurately. However, when a plurality of vehicles 7 are traveling on the course, the centralized control circuit 6 cannot determine which vehicle the present timekeeping belongs to. Therefore, in the present invention, the electromagnetic wave is cyclically emitted from the coil antenna 8 mounted on each vehicle to identify the reverse phase in the field B and at the same time, specify the address. Next, this configuration will be described. Basically, different addresses are given to the respective vehicles with respect to the emission timing of the electromagnetic waves, and the centralized control circuit 6 has a configuration for determining the addresses. FIG. 4 is a circuit diagram of the device mounted on the vehicle side. In the figure, 15 is an address switch for setting an individual address, and in the embodiment, it is composed of a 7-bit dip switch. Therefore, up to 128
Addresses can be set individually for each car. Reference numeral 16 is an oscillation circuit excited by a crystal oscillator, 17 is a frequency divider for dividing the oscillation frequency of the oscillation circuit 16, and a clock input of a 7-bit counter 18 is obtained. Then, if the 7-bit counter is counted up to the set value of the address switch 15 by this clock, the address matching circuit 19
Therefore, the coincidence output is performed only for one pulse. The output of the oscillation circuit 16 is superimposed on this coincidence output as an AC signal, amplified through the bandpass filter 20, and then transmitted from the vehicle-mounted transmission antenna 21. The vehicle-mounted transmission antenna 21 has the same concept as the coil antenna 8 in FIG. Therefore,
The output from the in-vehicle transmitting antenna 21 causes the field B
By capturing the timing at which the phase of the detection antenna 3 is reversed, the timekeeping and the address of the vehicle can be recognized at the same time. Further, since the timing is determined by the set address of the address switch 15, the centralized control circuit 6 can serially identify a plurality of vehicles only by determining the output timing from the in-vehicle transmitting antenna 21.

By the way, in order to determine the signal output timing from the on-vehicle transmitting antenna 21, the reference must be matched between the vehicle 7 side and the centralized control circuit 6 side. Therefore, in this embodiment, the counter 18 on the vehicle side is connected to the central control circuit 6.
A reset signal is transmitted to control the start of count-up, and the start-up of the counter provided in the centralized control circuit 6 described later coincides with the start of count-up. In FIG. 4, reference numeral 22 denotes a vehicle-mounted receiving antenna, which amplifies the reset signal when it receives the reset signal,
After being detected by the comparator circuit 2, it is smoothed by the low-pass filter 25, and is compared by the comparator circuit 2 through a high-pass filter 26 provided arbitrarily.
A signal having a level exceeding the threshold is taken out at 7 and input to the reset terminal of the counter 18 and the frequency divider 17. As a result, as long as the circuit of FIG. 4 receives the reset signal regularly, the signal is output from the vehicle-mounted transmission antenna 21 after a lapse of time corresponding to the set address. FIG. 5 shows timing waveforms in A to E of the circuit of FIG. 4, and shows output timing when the address of this car is set to 4.

Next, FIG. 6 shows an internal block of the centralized control circuit 6. Reference numeral 28 denotes an oscillation circuit excited by a crystal oscillator, and the oscillation frequency of the crystal oscillator is made to coincide with that of the oscillation circuit 16 in order to make the clock cycle coincide with the vehicle side. Reference numeral 29 is an N-ary counter, which has a count value of at least the number of vehicles for which addresses are set. The N-ary counter 29 outputs a pulse to the control pulse generation circuit 30 every cycle. The control pulse generation circuit 30 outputs a pulse according to the pulse received from the N-ary counter 29, and transmits a transmission wave on which the waveform generated by the oscillation circuit 31 for carrier generation is superimposed from the transmission antenna 5 via the amplifier 32. To do. That is, this transmitted wave is received by the vehicle-mounted detection antenna 22 and functions as a reset pulse for the device mounted on the vehicle 7. Since the reset pulse is cyclically output from the transmitting antenna 5, electromagnetic waves are output from the vehicle-mounted transmitting antenna 21 before the control line on the vehicle side, but the centralized control device 6 processes the electromagnetic waves as an effective output. This is only when the induced currents of the detection antenna 3 and the comparison antenna 4 have opposite phases. In this way, the central control device 6 transmits a reset pulse to the vehicle, but the count of the N-ary counter 29 is proceeding in accordance with the count value of the 7-bit counter 18 mounted on the vehicle. . Therefore, when the signal detection circuit 33 of FIG. 6 detects the reverse phase pulse received from the vehicle 7, the latch timing pulse is output to the data latch circuit 34 at this pulse timing. Data latch circuit 34
Since the count value of the N-ary counter 29 is sequentially read, if the count value at the latch timing is determined, the address of the vehicle having that timing can be determined. Therefore, the N-ary counter 2 when the latch timing pulse is input to the data latch circuit 34
The vehicle number can be confirmed by reading the count value of 9, and the required time can be measured by reading the clock at that timing. FIG. 7 shows timing waveforms at points A to F in the circuit of FIG. The internal block of the signal detection circuit 33 is shown in FIG.
The block diagram shown in FIG.

The delay time differs between the vehicle-mounted circuit and the centralized control circuit 6 due to the difference in the internal circuit configuration. Therefore, the timing at which the reset pulse is output from the centralized control circuit 6 to activate the on-vehicle counter 18 and the timing at which the data latch circuit 34 latches the count value of the N-ary counter 29 can be deviated strictly after the constant calculation. Of course there is. As a result, the timing setting such that the output timing of the signal detection circuit 33 and the output timing of the count value from the N-ary counter 29 to the data latch circuit 34 match is finally determined by constant calculation or the like.

As described above, by giving different addresses to a plurality of traveling vehicles respectively, the timing at which the coil antenna 8 outputs an electromagnetic wave in the field B of FIG. 2 is grasped, and the time measurement and the address determination are performed simultaneously. be able to. Strictly speaking, this timing is not always right above the control line 2, but it is not a big problem if the distance between the detection antenna 3 and the comparison antenna 4 is shortened. For example, if the distance between the two is set to 50 cm, the traveling time is 6/1000 seconds assuming that the car travels at 300 km / h, but if the clock frequency used in the counting oscillation circuit is set high, the count will be counted. Since the period is very short, the actual error is very small.

By the way, in the case of a linear fixed antenna such as the detection antenna 3 and the comparison antenna 4, the position where the coil antenna 8 passes, that is, the position where the coil antenna 8 passes with respect to the length of the antenna. The level of the induced current varies depending on the value. For example, as shown in FIG. 8, the reception level is different when the coil antenna 8a passes the detection antenna 3 and when the coil antenna 8b passes. This is because the induced current generated in the detection antenna 3 includes a traveling wave and a reflected wave as seen from the receiving end 3a, and this combined waveform appears at the receiving end 3a.
In particular, due to the relationship between the wavelength and the antenna length, the traveling wave and the reflected wave may completely cancel each other and cancel each other, and the reception level may become zero. In this embodiment, in order to avoid this, a resistor 3c for impedance matching is provided at the reflection point as shown in FIG.
The reflected wave is absorbed. As a result, the reception level can be reliably detected without being affected by the position where the coil antenna passes.

In the present embodiment, the moving body has been described as a race car in a circuit race, but in addition to this, any structure may be used if the moving time of a plurality of high speed moving bodies traveling on a loop-shaped moving path is individually measured. This system can be used, and not only can the fixed antenna be installed on the road surface, but it can also be suspended in the air. The antenna installation position is arbitrary as long as the coil antenna and the fixed antenna are not too far apart.

[0020]

According to the present invention, the fixed antenna is provided on the traveling path.
This is provided in parallel and the phases of the induced currents generated by the electromagnetic waves generated by the coil antenna mounted on the moving body are compared with each other and only the opposite phase timing is extracted, so the elements to detect are very clear. In addition, even when a plurality of moving bodies pass in succession, it is possible to reliably and individually determine each timing. In addition, it is hardly affected by external noise,
The device has high reliability.

Further, counters are provided on the detecting side and the moving body side respectively, and both counters are reset by the radio wave output from the detecting side, the count values are advanced in synchronization, and the address preset in the moving body is set. Then, the excitation timing of the coil antenna is generated, and the detection side reads the timing to measure the time, and at the same time, reads the synchronized self-count value at that timing. Therefore, at the same time as measuring the time, it is possible to determine the address of the mobile unit that generated the timing,
The time measurement and the identification of the moving body were reliably related, and it became possible to confirm the passage accurately.

Furthermore, since the impedance matching load is applied to the fixed antenna, interference due to reflected waves does not occur in the measurement of the induced current, and stable measurement can be performed.

[Brief description of drawings]

FIG. 1 is a plan view showing an antenna position of a device of the present invention,

FIG. 2 is a plan view for explaining phases of currents generated in two antennas,

FIG. 3 is a block diagram showing a circuit for extracting only the reverse phase timing;

FIG. 4 is a block diagram showing a circuit on the mobile body side;

5 is a timing waveform chart of main points in the circuit of FIG.

FIG. 6 is a block diagram showing a circuit on a centralized control device side;

7 is a timing waveform diagram of main points in the circuit of FIG.

FIG. 8 is a plan view showing a conventional example of a fixed antenna,

FIG. 9 is a plan view showing a fixed antenna of this embodiment,

FIG. 10 is a plan view showing a conventional measuring method,

FIG. 11 is a plan view of the same.

[Explanation of symbols]

 3 Detection Antenna 4 Comparison Antenna 5 Transmission Antenna 6 Centralized Controller 7 Moving Object 8 Coil Antenna 11 Synchronous Detection Circuit 15 Address Switch 16 Oscillation Circuit 18 7-bit Counter 19 Address Matching Circuit 21 In-vehicle Transmission Antenna 29 N-ary Counter 30 Control Pulse Generation Circuit 34 Data latch circuit

Claims (3)

[Claims] 1. A coil comprising: a moving body equipped with a coil antenna for generating an electromagnetic wave; a detection antenna provided on a traveling path of the moving body; and a comparison antenna provided in front of the detection antenna in a traveling direction. A passage confirmation device for a moving object, characterized in that the phases of induced currents of the detection antenna and the comparison antenna by electromagnetic waves generated in the antennas are compared, and the timings of these induced currents having opposite phases are detected. 2. In addition to a detection antenna and a comparison antenna, a transmission antenna is further provided on the traveling path, and a pulse for exciting the coil antenna is periodically transmitted from the transmission antenna, while the transmission antenna is unique to the moving body. When the address is set and the above pulse is received, the internal counter is advanced,
If the address value is matched, a pulsed exciting current is passed through the coil antenna, and a counter that advances in synchronism with the internal counter of the moving body is provided on the detection antenna side. 2. The passage confirming device for a moving body according to claim 1, wherein the numerical value of the counter is read at the same time when the timing at which the phase is reversed is read. 3. A detection antenna and a comparison antenna,
2. The passage confirmation device for a moving body according to claim 1, wherein a load for impedance matching is provided at a reflection point on the opposite side of the receiving end.