JPH08106595A - Method and device for ultrasonic warning against parking violation - Google Patents

Abstract

PURPOSE: To provide a method and device for ultrasonic warning against parking violation capable of detecting always correctly the parking violation even from a distant place. CONSTITUTION: An ultrasonic wave pulse group is emitted from an echo sounder transmitter 1 toward a target by driving it by an oscillation circuit 2. By controlling the oscillation circuit 2 by a timing control circuit 4 and a frequency control circuit 3, plural pulses different in frequency are emitted as the ultrasonic wave pulse group. A reflected wave from the target vehicle is caught by an echo sounder receiver 5, and is converted into an electric signal. An echo sounder reception signal is sent from a signal processing circuit 8 to a discrimination circuit 9, and the presence of the parking violating vehicle is discriminated, and warning is given by an annunciator 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a warning method and a device therefor for instantaneously detecting an illegal parking / stopping on a road by an ultrasonic method to give a driver's attention.

[0002]

2. Description of the Related Art A device for detecting a parking violation or a parking violation using ultrasonic waves and issuing a warning has already been proposed and implemented. FIG. 3 is a block diagram of an example of this conventional device. In this conventional device, the ultrasonic wave pulse is emitted from the wave transmitter 21 toward the target by being driven by the oscillation circuit 22. The timing control of this pulse emission is performed by the timing control circuit 23, and a single ultrasonic pulse is continuously emitted at appropriate intervals. The ultrasonic pulse emitted in this manner hits the target parking violation vehicle, is reflected, becomes a reflected wave of the ultrasonic pulse, returns, and is incident on the wave receiver 24. The received signal from the wave receiver 24 is sent to the determination circuit 26 via the signal processing circuit 25,
It is determined whether or not there is a parking violation vehicle. And
Based on the result of this determination, the alarm 27 issues a warning.

[0003]

However, the above-mentioned conventional device has a short detectable distance and can accurately detect only at a short distance of about 3 to 4 m. At a longer distance than that, There is a problem that many detection errors occur. This is because the ultrasonic waves are easily affected by atmospheric conditions such as rain, fog, and wind, and are attenuated while advancing in the atmosphere to reduce the sound pressure level at the time of reception, or the frequency fluctuates. Therefore, when using a single-shot pulse as in the past,
If this pulse is strongly affected by the atmosphere and interferes with the reception, it will immediately lead to a detection error. Further, the influence of the atmosphere is proportional to the distance, and the detection accuracy decreases as the distance to the target becomes longer. Therefore, the conventional apparatus can detect the illegal parking with sufficient accuracy in practical use only at the short distance as described above. Could not be done. However, if the detectable distance is such a short distance, the detection device has to be installed in a short distance from the space where the vehicle is illegally parked, which greatly restricts the installation of the device and causes a problem in usability.

In addition, ultrasonic wave transmitters and receivers have a property that the resonance frequency thereof varies with temperature. As a result, a difference occurs between the frequency transmitted / received and the resonance frequency, the transmitted sound pressure level of the ultrasonic pulse emitted from the transmitter decreases, or the received signal obtained from the receiver The level will drop and detection will be hindered.

In view of the above points, the present invention is to provide a parking violation warning method and an apparatus therefor, which makes it difficult to be affected by the atmosphere and can accurately detect a violation parking even from a long distance.

Further, according to the present invention, the influence of the fluctuation of the resonance frequency of the transmitter / receiver due to the ambient temperature is prevented,
An object of the present invention is to provide a parking violation warning method and a device therefor that can always perform accurate detection.

[0007]

The technical means of the parking violation warning method of the present invention aims at an ultrasonic pulse group consisting of a plurality of pulses emitted at a constant time interval in one oscillation time zone. While transmitting toward the ultrasonic pulse group, the ultrasonic pulse group transmission is continuously repeated with a fixed stop time period, and the reflected wave from the target of the ultrasonic pulse group is received.
The received signal is processed and discriminated, and a warning is issued when a parking violation is detected.

It is also possible to make the frequencies of the ultrasonic pulse groups to be transmitted different.

The technical means of the parking violation warning device of the present invention is a wave transmitter for emitting a group of ultrasonic pulses, an oscillator circuit for driving the wave transmitter, and a timing control for controlling the pulse oscillation time of the oscillator circuit. A circuit, a wave receiver that receives the emitted waves of the emitted ultrasonic pulse group and converts them into an electrical signal, a signal processing circuit that amplifies and detects the received signal, and an arithmetic processing of the received signal It is composed of a discrimination circuit for confirming the illegal parking and an alarm device which operates according to the discrimination result.

Further, the frequency control circuit may change the oscillation frequency of the ultrasonic pulse group oscillated by the oscillation circuit.

Further, as a discriminating circuit, a masking circuit for selectively removing a received signal from an object other than the target and a received signal from a transmitted pulse group for one time are arithmetically processed to determine whether the target vehicle exists. , A pulse group logical sum operation circuit for determining whether or not, a storage circuit for storing the determination result, and a logic for processing the plurality of stored determination results to determine whether or not the target vehicle is stopped. It is also possible to use a product arithmetic circuit.

[0012]

In the present invention, the ultrasonic pulse to be emitted is not a single shot but a pulse group consisting of a plurality of pulses. That is, a plurality of ultrasonic pulses are continuously emitted at a constant time interval in one oscillation time zone, and further, a certain oscillation stop time zone is set and a plurality of pulses are similarly emitted in the next oscillation time zone. Is fired. Since the influence of the atmosphere on ultrasonic waves appears as fluctuations within a very short time, if multiple pulses are emitted at fixed time intervals, at least one pulse will be reflected with almost no effect. Then, it becomes incident on the receiver. The present invention utilizes this theory, the emission of ultrasonic waves is performed as a pulse group, and from among the plurality of emitted pulses, at least one pulse reflected without being affected by the atmosphere is captured, The detection discrimination is performed from the received signal. Therefore, the detection accuracy can be increased and the detectable distance can be extended accordingly.

The received signal is first amplified and detected, and then subjected to temporal masking processing to remove the reflected signal from an object other than the target vehicle. Next, the received signals of the pulse group for one time are subjected to logical sum operation processing to determine whether or not the target vehicle exists. Then, this determination result is stored, and a logical product calculation process is performed on a plurality of determination results within a fixed time to determine whether or not the target vehicle is stopped. In this way, a warning is issued when the parked vehicle is confirmed.

Further, if the frequencies of the plurality of oscillating ultrasonic pulses are slightly shifted and made different, even if the resonance frequency of the transmitter or the receiver fluctuates due to the environmental temperature, the oscillation frequency will be Either one will match the resonance frequency. Therefore, even if the temperature changes, accurate detection is always possible.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram thereof. Reference numeral 1 denotes a wave transmitter that emits an ultrasonic pulse group toward a target. In the embodiment, an ultrasonic ceramic sensor (for transmission) is used. This wave transmitter 1 is driven by a pulse group oscillating circuit 2 to emit a plurality of ultrasonic pulses in a group. The number of pulses in one group is 2 or more, and 4 or 8 is suitable.

The frequency of the ultrasonic pulse oscillated is controlled by the frequency control circuit 3. That is, the oscillation frequency is matched with the resonance frequency of the wave transmitter 1. However, since the resonance frequency fluctuates depending on the environmental temperature, anticipate the range of the fluctuation and shift the oscillation frequency little by little within this range, and even if the resonance frequency fluctuates, either oscillation frequency will match this. As described above, the frequency is set in advance and the ultrasonic pulse group is oscillated. In the example, 39, 39.5,
Ultrasonic pulses of four frequencies of 40 and 40.5 kHz are oscillated.

The emission time of the ultrasonic pulse group is controlled by the timing control circuit 4. That is, as shown in FIG. 2, a plurality of ultrasonic pulses are continuously emitted at a constant short time interval in one oscillation time zone. Then, a certain oscillation stop time period is set, and then a plurality of pulses are similarly emitted in the oscillation time period. In the example,
The pulse time width is 2 ms, and the pulse oscillation interval is 250 m
s, the oscillation time period is 750 ms, and the oscillation stop time period is 3.
The firing cycle was set to 25 s and the firing cycle was set to 4 s.

In the test result of the embodiment, about 10 m is obtained by setting the ultrasonic pulse group as described above.
A distant target vehicle could always be detected accurately. Therefore, the detectable distance, which was only 3 to 4 m in the past, could be greatly extended.

The ultrasonic pulse emitted from the transmitter 1 is
The offending vehicle, which is a target, hits and is reflected, and becomes a reflected wave to enter the wave receiver 5. In the embodiment, an ultrasonic ceramic sensor (for reception) is used as the wave receiver 1. The wave receiver 1 converts the incident reflected wave into an electric signal. The received signal is amplified and detected by the signal processing circuit 8 including the amplification circuit 6 and the detection circuit 7.

The received signal processed in this way is sent to the discrimination circuit 9. The discrimination circuit 9 of the embodiment includes a masking circuit 10, a pulse group OR operation circuit 11, a storage circuit 12,
It is composed of a logical product operation circuit 13. The masking circuit 10 removes the received signals from objects other than the target vehicle. That is, the masking circuit 10 is controlled by the timing control circuit 4, predicts the time until the reflected wave returns, based on the distance to the target vehicle, determines a fixed time range, and determines the time range outside this range. The received signal is removed. By this masking, the signal to be discriminated can be selected only as the received signal from the target vehicle.

Next, the received signal subjected to the selection processing is sent to the pulse group logical sum operation circuit 11 controlled by the timing circuit 4 and subjected to operation processing to determine whether or not there is a violating vehicle at the target position. To be determined. That is, this circuit 11
Only the pulse group of one time is the target of discrimination. Then, if the received signal by one pulse of this pulse group is the set value, it is determined that the target vehicle exists.

The result of this determination is stored in the storage circuit 12. The logical product arithmetic circuit 13 is controlled by the timing circuit 4 and arithmetically processes the signals stored within a certain period of time to determine whether the target vehicle is moving or stopped. When the presence of the stopped vehicle is confirmed, a signal is sent to the alarm device 14 to issue a warning. As the notification device 14, a voice warning by a speaker, a sounding warning by a buzzer, a blinking warning by a light emitting device, a character warning by an electronic display plate, or the like can be used.

The present invention is not limited to the above-mentioned embodiments, but can be freely modified within the scope of the claims.

[0024]

According to the warning method of the present invention as set forth in claim 1, since the palace group which is emitted at a constant time interval is used for the ultrasonic pulse to be transmitted, even if the ultrasonic wave is rain, fog or wind. Even if the atmosphere is adversely affected, the reflected wave of at least one pulse in the pulse group can be received almost normally. As a result, the detectable distance of the infringing vehicle can be greatly extended compared to the conventional case, the restriction on the installation of the device is reduced, and the usability is improved.

According to the method of claim 2, since the frequencies of the oscillating pulse groups are different, even if the resonance frequency of the transmitter or the receiver fluctuates due to the ambient temperature, any one of the oscillation frequencies To match the resonance frequency,
Accurate detection is always possible.

In addition to the effect of the invention of claim 1, the warning device of the invention of claim 3 has a simple structure, can be miniaturized, and can be easily installed anywhere. Has the above effect.

According to the apparatus of claim 4, in addition to the effect of the invention of claim 2, it is possible to easily oscillate ultrasonic pulse groups having different frequencies, and to manufacture the apparatus at low cost. Have.

In the apparatus according to the fifth aspect of the present invention, since the two-step discrimination process of whether or not the target vehicle exists and whether or not the target vehicle is stopped, the parking violation can be detected with high accuracy. In addition, the structure for discrimination is simple and can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of a warning device of the present invention.

FIG. 2 is a diagram showing a situation of emitting ultrasonic pulses.

FIG. 3 is a block diagram of a conventional device.

[Explanation of symbols]

 1 wave transmitter 2 pulse group oscillation circuit 3 frequency control circuit 4 timing control 5 receiver 6 amplification circuit 7 detection circuit 8 signal processing circuit 9 discrimination circuit 10 masking circuit 11 pulse group OR operation circuit 12 memory circuit 13 AND operation Circuit 14 Alarm

Claims (5)

[Claims] 1. An ultrasonic pulse group consisting of a plurality of pulses emitted at a constant time interval in one oscillation time zone is transmitted toward a target, and this ultrasonic pulse group transmission is constant. Repeatedly with the stop time zone of this, receive the reflected wave from the target of this ultrasonic pulse group, process and discriminate the received signal, and issue a warning when illegal parking is detected Ultrasonic parking violation warning method. 2. The ultrasonic parking violation warning method according to claim 1, wherein the frequencies of the ultrasonic pulse groups to be transmitted are different. 3. A wave transmitter for emitting an ultrasonic pulse group, an oscillating circuit for driving the wave transmitter, a timing control circuit for controlling a pulse oscillation time of the oscillating circuit, and an ultrasonic wave group for emitting the ultrasonic pulse group. A receiver that receives the emitted wave and converts it to an electric signal, a signal processing circuit that amplifies and detects the received signal, a determination circuit that processes the received signal and confirms illegal parking, and this determination An ultrasonic parking violation warning device comprising an alarm that operates according to the result. 4. A frequency control circuit is attached to the oscillation circuit,
The ultrasonic parking violation warning device according to claim 3, wherein the oscillation frequencies of the ultrasonic pulse groups are made different. 5. A masking circuit for selectively removing a received signal from an object other than the target by a discriminating circuit, and a received signal from a transmitted pulse group for one time are subjected to arithmetic processing to determine whether a target vehicle exists. , A pulse group logical sum operation circuit for determining whether or not, a storage circuit for storing the determination result, and a logic for processing the plurality of stored determination results to determine whether or not the target vehicle is stopped. The ultrasonic parking violation warning device according to claim 3, comprising a product calculation circuit.