JP2003016592A - Alarm device for driving vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an alarm device with high reliability by which even an object with an irregular shape such as a child in soft clothes is surely detected even in a case with a bad condition for detecting an obstacle to secure safety in driving a vehicle and also the object is sufficiently detected regardless of distance to the object. SOLUTION: The vehicle is provided with a sensor unit on the outer surface which consists of an audio acoustic speaker and a small microphone. A control display unit is arranged in the driving room of the vehicle, which is connected to a position close to a driving seat so as to exchange information with the sensor unit. The acoustic speaker is driven to emit a plurality of measurement sonic waves being different in frequency at short interval from an originating part which is disposed in the control display unit. The distance is calculated through the use of a time difference between a time when the measurement sonic waves emitted from the acoustic speaker are reflected against the obstacle and a time when they are inputted to the microphone and, then, the obstacle is displayed on the display part of the control display unit as an obstruction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a wave transmitter for transmitting sound waves and a wave receiver for detecting a sound wave reflected from a sound wave transmitted from the vehicle and hitting an obstacle on the front and rear surfaces of the vehicle. The present invention relates to an improvement of a warning device in vehicle driving, which detects the presence or absence of an unspecified obstacle in front of, below, and behind the vehicle when the vehicle moves forward and backward, and ensures safe driving of the vehicle.

[0002]

2. Description of the Related Art The above-mentioned warning device for driving a vehicle includes
In order to detect obstacles existing in the front and rear of the vehicle, an ultrasonic sensor device using piezoelectric ceramic is used, and its ultrasonic transmitter and ultrasonic receiver are installed on the front and rear surfaces of the vehicle. Then, it transmits an ultrasonic pulse signal from its ultrasonic wave transmitter, collides it with an obstacle that is an object to detect it, and causes the ultrasonic wave receiver to receive the reflected wave. At this time, the time from the transmission of the ultrasonic wave transmitted from the ultrasonic transmitter to the reception by the ultrasonic receiver is measured by the microprocessor incorporated in the display means provided in the driver's seat of the vehicle. A means is known in which a distance to an obstacle is calculated, the presence or absence of the obstacle is determined based on the distance, and the result is displayed on the display unit.

[0003]

By using the ultrasonic sensor to which the above-mentioned piezoelectric ceramic is applied, an obstacle existing in front of or behind the vehicle is detected when the vehicle travels in the front or rear direction. Means for ensuring safe driving are effective as such, but there are problems in the following points.

The first problem is that the ultrasonic sensor cannot produce a large transmission output due to its element structure. The output is 100 milliwatts to 500 in a normal commercial product.
The strength is about 100 dB at about milliwatt, and the detection distance is about 3 meters at maximum and the sensitivity is at most. Therefore, if there is a little distance, it is almost impossible to distinguish,
Further, for example, when it is raining, when the ultrasonic wave transmitter / ultrasonic wave receiver is dirty, or when the conditions are bad, the sensitivity is lowered and the detection cannot be performed.

The second problem is that the sensor using the ultrasonic transducer uses a single frequency, and is therefore well suited for objects whose material is hard and whose outer surface shape is clean. Then, it becomes possible to distinguish even small things, but when used to ensure the safety of driving a vehicle, even if structures such as fire hydrants on the road can be distinguished,
Children covered with soft clothes and trees with soft leaves may not return due to disturbed direction of reflected waves. Also, the object to be detected is hard,
Depending on the reflection angle and distance of the object, even if the shape is uniform, the phases of the transmitted wave and the reflected wave are symmetrically opposite to each other, so that the transmitted wave and the reflected wave cancel each other out. As a result, it may not be detected.

The present invention has been made in order to solve the above-mentioned problems that have occurred in the warning means for ensuring the safety of the operation of a conventional vehicle using this ultrasonic sensor. Even when the condition is bad, it is possible to reliably detect objects with irregular shapes such as children wearing soft clothes, and even if there is a distance to the object, it is possible to detect with sufficient reliability. It is an object of the present invention to provide a high warning means for ensuring the safety of vehicle driving.

[0007]

In the present invention, as a means for achieving the above-mentioned object, the invention is defined by
A sensor unit consisting of an audio speaker for audio and a small microphone is provided on the outer surface of the vehicle, and a wireless or wired communication is provided near the driver's seat in the cab of the vehicle to exchange information with the sensor unit. Alternatively, a control display unit connected by optical communication is provided, and a plurality of measurement sound waves of different frequencies are driven to be emitted after a short time by a transmission unit driven by a microcomputer equipped with an acoustic speaker in the control display unit, The time difference between the sound waves emitted from the acoustic speaker and being reflected by the obstacles and input to the microphone is measured by the microcomputer to calculate the distance, which is displayed as an obstacle on the display unit of the control display unit. The present invention provides a warning device for driving a vehicle characterized by the above.

In addition to this, in the transmitting circuit incorporated in the control unit of the control display unit so as to transmit the measured sound wave according to the second aspect, the measured sound waves having different frequencies are extremely short, about 1 / 10,000 second. A plurality of transmitters that emit timely are set so as to be driven at a short time interval of about 1/20 second, and the receiving circuit incorporated in the control unit has a transmitter provided in the transmitting circuit. Immediately after driving
2. The vehicle operation according to claim 1, wherein a gate circuit with a filter set to be driven is provided with a gate time set to a time shorter than the time interval for driving the oscillator. Raise a warning device,

Further, in the transmitting circuit incorporated in the control section of the control display unit so as to emit the measured sound wave, the driving circuit of the alarm device driven to emit the warning sound is provided in the transmitting circuit. It is driven within the time interval between the driving of a plurality of oscillators and the driving of the gate circuit provided with the driving time set in the receiving circuit and the driving of the next gate circuit. The warning device for vehicle operation according to claim 1 or 2, wherein the warning device is set as described above.

Further, a plurality of sensor units, each of which is a combination of an audio speaker for audio and a small microphone according to claim 4, are installed on the rear side of the vehicle in parallel vertically and horizontally. 2. The warning device for driving a vehicle according to claim 1, wherein the acoustic speaker of the unit is set to be driven with a time difference.

A sensor unit comprising a combination of an audio loudspeaker for audio and a small microphone according to claim 5 is provided on the rear surface side of the vehicle, on the left and right side portions of the lower portion on the rear surface side and on the both side portions of the upper portion. A plurality of sensor units are installed in parallel with each other, and those sensor units are driven in synchronization with the acoustic speaker of the sensor unit on one side of the lower left and right and the acoustic speaker of the sensor unit on the other side of the upper left and right, The lower left and right side sensor unit acoustic speakers and the upper left and right side sensor unit acoustic speakers are combined in a plow shape in rear view so that they are driven in synchronization, and each combination is driven with a time difference. The warning device according to claim 1, wherein the warning device is set as follows.

According to the sixth aspect of the present invention, a control circuit is provided with a discrimination circuit for discriminating the volume of noise around the vehicle input to the microphone of the sensor unit mounted on the outer surface of the vehicle. A photo sensor that detects the intensity of external light is provided, and when this and the discrimination circuit detect a dark and quiet external environment, the warning sound emitted from the alarm device is controlled to be low. The warning device for driving a vehicle according to claim 1, wherein the warning device is set.

According to a seventh aspect of the present invention, a schematic image in a plan view of the vehicle is displayed and detected on the screen of the display unit of the control display unit disposed near the driver's seat in the driver's cab of the vehicle. The vehicle driving according to claim 1, wherein the image displaying the existence of the obstacle is displayed in a mode in which an outline position with respect to the vehicle is displayed around the image of the vehicle based on the image of the vehicle. Is to present a warning device in.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION A warning device for safe driving of a vehicle according to the means of the present invention is located at a position where it is difficult to see from the driver's seat in front of the traveling direction when the vehicle is moved forward or backward. When the obstacle is detected by the emitted sound wave and the reflected wave reflected by the sound wave hitting the obstacle, the transmitter provided on the outer surface of the vehicle to emit the sound wave is used in the conventional means. Acoustic speaker with a cone for audio without using the ultrasonic wave transmitter of the sensor that uses the ultrasonic transducer applying piezoelectric ceramics
To use.

The receiver for receiving sound waves also uses a normal small microphone 2 used in audio equipment.

The acoustic speaker 1 and the microphone 2 are combined as shown in FIG. 1 to form a sensor unit SU.
For example, in the case where the vehicle to be mounted is a freight vehicle, as shown in FIG. 2, driving in the cab 30 of the vehicle 3, such as upper and lower portions of the rear surface and the front surface of the vehicle 3, is performed. The vehicle is mounted on the outer surface of the vehicle 3 at an appropriate position so that sound waves are emitted from the acoustic speaker 1 toward an area where the driver sitting on the seat 31 cannot see through.

The acoustic speaker 1 and the small microphone 2 provided on the outer surface of the vehicle in combination as the sensor unit SU are constructed in the sensor unit block SUB as shown in FIG.
As shown in FIG. 1 described above, the control display unit DU arranged and installed near the driver's seat 31 in 0 is connected so that information can be exchanged. This connection may be for wired or wireless or optical communication as appropriate,
At this time, the transmission / reception units a and b may be used for connection as shown by the chain line in FIG.

As described above, using the acoustic speaker 1 with the cone for audio as the transmitter and the small microphone 2 for audio as the receiver allows the power to be used freely and the power to be increased. It is easy to obtain a large transmission output, for example, even if an acoustic speaker of about 10 watts is used, the output is 10 to 100 times higher than that using a sensor using an ultrasonic transducer for a transmitter. Therefore,
As a result, it is possible to obtain sufficient detection capability even under adverse conditions, and since it is an acoustic speaker, the frequency can be set freely from 100 Hz to 50 kHz, and sound waves of various types of frequencies are output as measurement sound waves. It is possible to increase the reliability of detection of an obstacle made of an unspecified material.

From this fact, the acoustic speaker 1 used as the wave transmitter may be of about 10 watts. As the plurality of measurement sound waves emitted from the acoustic speaker 1, for example, at least two kinds of frequencies such as a first frequency f1 of 30 kHz and a second frequency f2 of 40 kHz are emitted.

The sensor unit SU in which the acoustic speaker 1 and the microphone 2 are combined is provided on the rear side and the front side of the vehicle 3, respectively, so that when the vehicle 3 moves backward or moves forward. ,
It becomes possible for the driver to detect an obstacle existing at a position immediately above and below behind or in front of the vehicle 3 which is difficult for the driver to see. At this time, the sensor units SU ... 3 may be provided at a plurality of places on the left and right corners on the lower side of the rear surface and the left and right corners on the upper side, and by doing so, when the obstacle is a short child, etc. , It becomes possible to cope with both cases where the signboard is overhanging at a high position along the road.

Further, as described above, a plurality of sensor units SU ... Are mounted on the rear side of the vehicle 3 side by side vertically and horizontally, whereby each sensor unit SU ...
When increasing the detection area by, in order to avoid interference of the measurement sound wave and the reflected wave from each sensor unit caused by synchronizing the drive of multiple sensor units,
It is effective to give a time difference to the driving of the acoustic speakers 1 ... Of each sensor unit SU.

In this case, the plurality of sensor units SU ...
It is not always necessary to provide a time lag between the respective drives of the sensor units SU, for example, as shown in FIG. 3, the sensor units SU are arranged at the lower left and right corners on the rear side and the upper and left corners respectively. In the case of installation, the sensor unit SU-1 provided in the lower left corner is combined with the sensor unit SU-2 provided in the upper right corner to synchronize the drive, and the lower right corner is provided. Measurement is performed by combining the provided sensor unit SU-3 and the sensor unit SU-4 provided at the upper left corner to synchronize the drive, and by providing a time difference in the drive of these combined sensor units SU ... It is possible to expand the area to be detected by suppressing the interference generated in the sound wave and its reflected wave.

FIG. 6 is a block diagram of a warning device W for driving a vehicle in which the means of the present invention is implemented. In the figure, 4 is a control unit of the control display unit DU and 5 is a detection result on the screen. A display unit for displaying images, SU is a sensor unit mounted on the outer surface of the vehicle 3, 1 is an acoustic speaker incorporated in the sensor unit SU, 2 is a small microphone combined with it, and 7 is ambient brightness. A photo sensor that is mounted on the outer surface of the vehicle 3 for detection, and serves as a noise sensor around the vehicle in cooperation with a noise detection microphone 2-4 that also serves as an obstacle detection microphone. A signal source that is a start switch that starts the control unit 4, and M represents an obstacle that is an object to be detected.

Reference numeral 41 denotes a microprocessor incorporated in the control unit 4, which controls and sets various devices.

The signal source 40 is a control display unit DU.
The switch may be provided as a switch for starting the detection operation of the control unit 4 by operating it to turn it on.
It is also possible to activate the control unit 4 by turning on the shift gear mechanism equipped in the vehicle when it is shifted to the back position.

Reference numeral 42 denotes a switching device which is activated when the signal source 40 is turned on, and includes a first oscillator 43 and a second oscillator 44.
Operates by alternately switching and.

The first oscillator 43 is an ordinary oscillator,
In this embodiment, a transmitter that emits a sound wave having a frequency of about 40 KHZ is used. Although the second oscillator 44 is a normal oscillator, it is a transmitter that emits a sound wave having a frequency of about 30 KHZ, and thereby a plurality of measurement sound waves having different frequencies are alternately emitted.

The first oscillator 43 and the second oscillator 44
As for the operation of emitting the measurement sound wave from, when the signal source 40 is turned on and the measurement is started, the operation of the switching device 42 is immediately after the time point 80 according to the timing chart in the first stage of FIG. Then, the first oscillator 43 emits 81 the first frequency which is the measurement sound wave of the frequency set to the first oscillator 43.
The first frequency emission 81 by the operation of the oscillator 43 is set by the above-mentioned microprocessor 41 so as to be a very short time of about 1 / 10,000 second (0.1 millisecond).
Controlled.

Following this, the second oscillator 44 is operated by the switching operation of the switch 42, and the second frequency emission 82 of another frequency set in this is performed. This emission 82
Similarly to the above, the time is set to an extremely short time of about 1 / 10,000 second. Then, the microprocessor 4 is set so that the time interval w between the first frequency emission 81 and the second frequency emission 82 is about 1/20 second (50 milliseconds).
Controlled and set by 1.

The operation of the first oscillator 43 and the second oscillator 44 may be further repeated with the above-mentioned pattern at the interval w of about 1/20 second described above, but in this embodiment, , The second transmitter 44 is activated and the time interval w described above is passed, and then a slightly longer time y is set. During this time, the rear sensor unit SU is
When the above-mentioned time interval w has passed after the emission 83 of the warning sound wave for the interpersonal warning by the warning sound transmission speaker which is also used as the speaker 1-4 incorporated in one of the above-mentioned ones, the first sound generator 43 and The second oscillator 44 and the second oscillator 44 operate in the manner controlled and set as described above.
I am trying to repeat it until the reverse of the car ends.

In FIG. 6, reference numeral 45 is a first frequency and a second frequency transmitted from the first oscillator 43 and the second oscillator 44.
In the shaping circuit for shaping the waveform of the frequency, the first frequency and the second frequency are respectively shaped here, and each of the sensor units SU mounted on the outer surface of the vehicle 3 by the preamplifier 46 connected thereto. Acoustic speaker 1
Are distributed to the driver amplifiers 47 ... And are emitted from the acoustic speakers 1 ... As measurement sound waves of respective frequencies.

48 are emitted from the respective acoustic speakers 1 of the sensor unit SU ..., collide with the obstacle M and reflect, and are provided in the respective sensor units SU ... in correspondence with the acoustic speakers 1. A magnifying circuit 49-1 for amplifying the signal of the reflected sound wave incident on a certain small microphone 2 ... Reflects the signal of the reflected sound wave of the first frequency transmitted from the first oscillator 43. A shaping circuit having a function of a filter for extracting only a signal wave of a sound wave, and a shaping circuit 49-2 having a function of a filter for extracting only a reflected sound wave of the second frequency transmitted from the second oscillator 44. The signal of the reflected sound wave shaped by these in the circuit is subjected to determination processing by the program of the microprocessor 41 provided in the control unit 4.

The second diagram of FIG. 7 is a timing chart of the control of the reflected sound wave in the receiving circuit in the microprocessor 41. Here, as shown in the first diagram of FIG. Emission of the first frequency by the first oscillator 43 8
Second frequency emission 8 after 1 and by second oscillator 44
Within the time interval w set after 2, the gate time z, which is shorter than the time interval w, is set by the gates 84, 84 provided in this receiving circuit.

The gate time z set here is a time for finding a reflected sound wave that is reflected and returned, and is set to an appropriate time depending on the accuracy required.

In the third row of FIG. 7, the first frequency f1 and the second frequency f emitted from the first oscillator 43 and the second oscillator 44 are shown.
2, the warning sound wave K · K emitted from the speaker 1 of the sensor unit SU-4, the first oscillator 43 and the second
The timing of each of the second frequency f1 and the second frequency f2 emitted again from the transmitter 44 is shown. Each frequency is emitted on the acoustic speaker 1 at this timing.

The fourth diagram is a timing diagram of the input sound waves input to the microphone for these sound waves.
f′2 is a reflected sound wave that is input by colliding with an obstacle.

In the fifth row, among the input sounds entering the microphone 2, the emission sound wave of the sound wave emitted from the second oscillator 44 does not return at the time of the first emission, and at the time of the second emission. It is a timing diagram when the reflected sound wave of the sound wave emitted from the 1st oscillator 43 is not weakly input.

The sixth diagram is a timing chart showing a state in which these input sound waves are extracted only to the first frequency f1 of the frequencies emitted from the first oscillator 43 via the first shaping circuit 49-1. Is.

Similarly, in the seventh row, the state in which the input sound wave is extracted into only the signal of the second frequency f2 of the frequency emitted from the second oscillator 44 through the second shaping circuit 49-2. FIG.

The eighth stage diagram is a timing chart in which the signals of the input sound waves that have passed through the first and second shaping circuits 49-1 and 49-2 are combined.

The ninth stage diagram shows the first frequency f1 and its reflected sound waves f'1 and second frequency f2 shown in the eighth stage diagram.
And the rising time t1 of each signal from the reflected sound wave f'2
・ T'1 ・ t2 ・ t'2 ・ t3 ・ t'3 ・ t4 ・ t'4
From FIG., The microprocessor 41 detects the time differences t × 1, t × 2, t × 3, and t × 4 and calculates the distance to the obstacle from the time difference.

The distance d to the obstacle determined by the time difference t can be represented by d = t / v × 0.5, as is well known. (V is the speed of sound 344 meters / second)

The lowermost figure shows the sensor unit S.
The case where the warning sound from the U-4 acoustic speaker 1 is changed to voice is shown. The warning sound may be a warning message such as "back" to a person behind the vehicle 3, for example.

As described above, the display unit 5 provided on the control display unit DU to display the obstacle M detected from the reflected sound wave uses a normal display which is displayed as an image on the screen. As shown in FIG. 1, the screen 5a thereof has a graphic 51 in plan view of the outline of the vehicle 3.
Is displayed in advance, and an obstacle M detected by reflected sound waves is displayed around the figure 51 with reference to the plane figure 51 of this vehicle, and a relative relation position between the vehicle 3 and the obstacle M is displayed. The image is displayed as a display mode.

In FIG. 8, 52 is a monitor lamp for notifying that the control unit 4 is operating, 53 is a buzzer for notifying the vehicle driver of the detection result of the obstacle,
Reference numeral 54 denotes a volume for adjusting the volume of the buzzer 53, which is provided as a touch switch on the screen 5a.

Referring again to FIG. 6, reference numeral 50 designates one of the plurality of sensor units SU, which are arranged in parallel with the photosensor 7 provided on the outer surface of the vehicle 3.
4 is a quiet sensor circuit configured by using the microphone 2 of FIG. 4, and a widening device 50-1 for widening a signal input to the photo sensor 7 for detecting the brightness outside the vehicle 3, and the sensor unit. The determination circuit 50-2 for determining the level of the external sound input to the microphone 2 of the SU-4 is incorporated, and combined with the level of the photo sensor 7, the warning sound for interpersonal use, the volume of the sensor unit is reduced. SU
The sound speaker 1 of -4 acts so as to emit the sound.

As a result, when the control unit 4 is operated and the vehicle 3 is retreated, the signal of the input sound from the external environment input from the microphone 2 and the photo sensor 7 are detected prior to that. The microprocessor 41 is made to judge the brightness and quietness from the signal of the brightness of the environment, and the volume from the acoustic speaker 1 of the sensor unit SU-4 is kept low in a dark and quiet residential area. I have to.

Next, in FIG. 9, a plurality of sensor units SU are provided on the rear surface side of the vehicle 3 at four positions on the upper left and right sides and the lower left and right sides, and these are synchronized with each other in a skewed manner to provide a time difference. It is a block diagram of the example made to operate.

In this example, the preamplifier 46, which is a distributor, is divided into a first preamplifier 46-1 and a second preamplifier 46-2, and the first preamplifier 46-1.
Distributes the signal in synchronization with the acoustic speaker 1 of the sensor unit SU-1 arranged in the upper left corner and the acoustic speaker 1 of the sensor unit SU-3 arranged in the lower right corner, and the second preamplifier 46-2 distributes the signal in synchronization with the acoustic speaker 1 of the sensor unit SU-2 arranged in the upper right corner and the acoustic speaker 1 of the sensor unit SU-4 arranged in the lower left corner. ,
In addition, these first and second preamplifiers 46-1.4
The microprocessor 41 is controlled so that the operation of 6-2 is performed with a predetermined time difference.

As a result, the sensor units SU mounted on the four corners of the rear surface of the vehicle 3 at the upper, lower, left, and right corners operate in pairs diagonally opposite to each other with a time lag to suppress the interference wave. There is.

[0051]

As described above, the warning device for driving a vehicle according to the means of the present invention uses an audio speaker for audio as a transmitter and a small microphone as a receiver. Since multiple different measurement sound waves are emitted with a large output and obstacles are detected by the reflected waves, a child covered with soft clothing that does not sufficiently reflect the measurement sound waves, or unspecified It becomes possible to accurately detect obstacles of various shapes, and it becomes possible to ensure the safety of vehicle driving.

[Brief description of drawings]

FIG. 1 is a system system diagram of a warning device in vehicle operation according to the means of the present invention.

FIG. 2 is an overall side view of the same apparatus as that mounted on a vehicle.

FIG. 3 is a rear view of the same apparatus as above.

FIG. 4 is a side view illustrating how the measurement sound wave is emitted in the same state as the above apparatus.

FIG. 5 is a plan view of the above.

FIG. 6 is a configuration diagram of an example of the same apparatus.

FIG. 7 is a timing chart for explaining the operation of the above apparatus.

FIG. 8 is a plan view of a display section of a control display unit of the same apparatus.

FIG. 9 is a configuration diagram of another embodiment of the same device.

[Explanation of symbols]

SU ... Sensor unit, DU ... Control display unit, W
... Warning device, M ... Obstacle, SUB ... Sensor unit block, a / b ... Transceiver unit, f1 ... First frequency, f
2 ... 2nd frequency, f'1, f'2 ... reflected sound wave, m ... hieroglyphics,
t1, t'1, t2, t'2, t3, t'3, t4,
t'4 ... rise time, w ... time interval, y ... time, z ...
Gate time, 1 ... Acoustic speaker, 2 ... Microphone,
3 ... vehicle, 30 ... driver's cab, 31 ... driver's seat, 4 ... control unit,
40 ... Signal source, 41 ... Microprocessor, 42 ... Switcher, 43 ... First oscillator, 44 ... Second oscillator, 45 ... Shaping circuit, 46 ... Preamplifier, 47 ... Driver amplifier,
48 ... Widening circuit, 49 ... Shaping circuit, 5 ... Display section, 5a ...
Screen, 50-1 ... amplifier, 50-2 ... judgment circuit, 51 ...
Graphic, 52 ... Monitor lamp, 53 ... Buzzer, 54 ... Volume, 7 ... Photo sensor, 80 ... Time point, 81 ... First frequency emission, 82 ... Second frequency emission, 83 ... Warning sound wave emission, 84 ... Gate .

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Claims (7)

[Claims] 1. A sensor unit comprising an audio speaker for audio and a small microphone is provided on an outer surface of a vehicle, and a wireless communication is provided in a driver's cab of the vehicle near a driver's seat to exchange information with the sensor unit. Alternatively, a control display unit connected by wired or optical communication is provided, and an acoustic speaker is provided in the control display unit, and is driven by a microcomputer controlled oscillator to emit a plurality of measured sound waves of different frequencies after a short time. Then, the time difference until those measurement sound waves emitted from the acoustic speaker hit an obstacle and are reflected and input to the microphone, the distance is calculated by measuring with the microcomputer,
A warning device in vehicle operation, characterized in that it is displayed as an obstacle on a display section of a control display unit. 2. A plurality of transmitters for transmitting the measurement sound waves having different frequencies for a very short time of about 1 / 10,000 second, to a transmission circuit incorporated in the control unit of the control display unit so as to emit the measurement sound waves. The receiver circuit is set so as to be driven at a short time interval of about 1/20 second, and the receiver circuit incorporated in the control unit is driven immediately after the oscillator provided in the oscillator circuit is driven. 2. The warning device in vehicle operation according to claim 1, wherein the gate circuit with a filter set as described above is provided with a gate time set to a time shorter than the time interval for driving the oscillator. 3. A driving circuit for an alarm device, which is driven to emit a warning sound, to a transmitting circuit incorporated in a control unit of a control display unit so as to transmit a measurement sound wave. It should be set so that it can be driven within the time interval between the driving of the gate circuit that is set to drive the receiving circuit and the driving of the next gate circuit within the interval between time and driving. The warning device in vehicle operation according to claim 1 or 2, characterized in that. 4. A plurality of sensor units, each of which is a combination of an audio acoustic speaker and a small microphone, are installed on the rear side of the vehicle in parallel vertically and horizontally, and the acoustic speakers of the sensor units are arranged with a time difference. The warning device for driving a vehicle according to claim 1, wherein the warning device is set to be driven. 5. A plurality of sensor units, each of which is a combination of an audio speaker for audio and a small microphone, are arranged on the rear side of the vehicle, on the left and right sides of the lower part on the rear side and on the both sides of the upper part. Individually installed, these sensor units are driven synchronously with the acoustic speakers of the sensor units on the left and right sides of the lower part and the acoustic speakers of the sensor units on the other side of the upper left and right sides, and Make sure that the acoustic speaker of the sensor unit and the acoustic speakers of the sensor units on the left and right sides of the upper part are combined in a plow shape in rear view so that they are driven with a time difference for each combination. The warning device for driving a vehicle according to claim 1. 6. A microphone for a sensor unit of an appropriate number of sensor units mounted on the outer surface of a vehicle,
The control unit is provided with a discrimination circuit for discriminating the volume of noise input around the vehicle, and a photosensor for detecting the intensity of external light is separately provided on the outer surface of the vehicle. The warning device according to claim 1, wherein when a dark and quiet state is detected, the warning sound emitted from the alarm device is controlled to be low. 7. The presence of an obstacle detected by displaying a schematic image of the vehicle in a plan view on a screen of a display unit of a control display unit arranged near the driver's seat in the driver's cab of the vehicle. 2. The warning device for driving a vehicle according to claim 1, wherein the image for displaying is displayed in a mode in which an outline position for the vehicle is displayed around the image of the vehicle with the image of the vehicle as a reference.