JPS6222108B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a failure detection device for an ultrasonic device that uses ultrasonic pulses.

Conventional obstacle detection devices using ultrasonic waves are used to confirm that the device is operating normally, and to check the operation time of the receiving wave circuit in relation to the circuit required for transmitting ultrasonic waves for direct waves and reflected waves. Differentiate based on time difference,
The operating state of the equipment was confirmed by receiving direct waves when necessary, and the display on the display device confirmed that the entire equipment was in operating state.

However, as disclosed in Japanese Patent Publication No. 50-23820, Japanese Patent Publication No. 51-36076, etc., when the ultrasonic transducer is operating normally, the transducer There is a device that detects a failure state by detecting the presence or absence of reverberation waves by utilizing the generation of reverberant waves due to vibrations caused by the device itself.

There is no problem with these devices when generating ultrasonic waves and receiving the reflected waves using a single transducer, but for example, if the transmitter and receiver are used independently,
If the fault detection circuit is provided at different locations, there is a problem in that two fault detection circuits are required to detect each fault.

The present invention has been made in view of the above points, and provides an independently provided transmission system. A failure of an ultrasonic device that is capable of detecting a failure of an independent transmitter and receiver with a simple configuration without providing a single failure detection circuit in an ultrasonic device equipped with a wave receiver. The object of the present invention is to provide a detection device.

Therefore, the present invention is directed to the delivery. In the ultrasonic device independently equipped with a receiver, a circuit is provided between the ultrasonic transmitter and the ultrasonic receiver, and a circuit that outputs a check pulse signal after a predetermined time from generation of the carrier wave pulse signal. a switch that is provided and becomes conductive upon receiving the check pulse signal; and a determining means that determines whether the signal from the ultrasonic receiver continues at a predetermined level or higher for a predetermined time after the switch becomes conductive; The apparatus is characterized by comprising means for notifying a failure of the ultrasonic device based on the determination result of the determining means.

According to the above configuration of the present invention, when the ultrasonic transmitter is normal, a damping vibration wave due to reverberation exists after the generation of the carrier wave pulse signal, and by conducting the switch, this transmitted wave is The reverberation waves of the device can be sent to the receiver. Then, when the receiver receives this reverberant wave, it again generates vibrations due to the reverberation when it is normal. In this way, when both the transmitter and receiver are normal, reverberant vibrations occur, but when either one is not normal, reverberant vibrations do not occur from the receiver. . Therefore, according to the above configuration, by providing one detection/discrimination circuit for the independent transmitter and receiver connected to the receiver, it is possible to detect the failure of both at the same time. This has the advantage that it can be implemented with a simple configuration.

Embodiments The present invention will be described below with reference to embodiments shown in the accompanying drawings. In FIG. 1, which is a block diagram showing the overall configuration of an embodiment of the present invention, reference numeral 1 indicates an ultrasonic carrier wave pulse signal, a gate signal for failure detection of an ultrasonic transmitter 2, and failure detection of an ultrasonic receiving system. 2 is an ultrasonic transmitter that receives an ultrasonic carrier wave pulse signal from the pulse generating circuit 1 and emits an ultrasonic wave; 3 is for detecting a failure of the ultrasonic transmitter 2; This is a switch that transmits a signal to the ultrasonic receiver 4, and the switch 3 is provided between the connection point a of the ultrasonic transmitter 2 and the connection point b of the ultrasonic receiver 4. 4 is an ultrasonic receiver that receives ultrasonic reflected waves from obstacles; 5 is a receiving circuit that receives the received wave signal from the ultrasonic receiver 4 and amplifies, selects, and detects the signal; 6 is a receiving circuit a level discrimination circuit that compares the levels detected in 5 and generates a received pulse; 7;
8 is an AND circuit that receives the fault detection gate signal generated by the pulse generating circuit 1 and the self-check signal of the self-check switch 8; 8 is a self-check switch that generates a self-check signal for checking the operation of the device; 9 is a self-check signal An inverter circuit receives the self-check signal from the check switch 8, 10 an AND circuit that receives the received pulse signal from the level discrimination circuit 6 and a signal from the inverter circuit 9, 11
12 is an AND circuit that receives the failure detection gate signal from the pulse generation circuit 1, the self-check signal from the self-check switch 8, and the received pulse signal from the level discrimination circuit 6; The receiving OR circuit 13 is a display circuit that receives the signal from the OR circuit 12 and displays it. The switch 3 and the AND circuit 7 constitute an application means, and the level discrimination circuit 6 and the AND gate circuit 11 constitute a discrimination means.

Next, the operation of the above structure will be explained with reference to the signal waveform diagram of each part shown in FIG. 1, 2, 3, 4, 5, 6 in Fig. 2 are a, b,
In the signal waveform diagram of sections c, d, e, and f, the waveform shown in FIG. 2 is the waveform that appears when the pulse generation circuit 1 and the ultrasonic transmitter 2 are connected. The excitation time t ₁ - t ₀ , t ₉ - _{t 8} ,
The waveforms are shown at t ₁₆ - t ₁₅ and during the relaxation times t ₆ - t ₁ , t ₁₄ - t ₉ and t ₁₉ - t ₁₆ after excitation of the ultrasonic transmitter 2.

Now, if the device with this configuration is operating normally, if the ultrasonic pulse is excited by the pulse generation circuit 1 from time t ₀ until time t ₁ , then if the ultrasonic transmitter 2 is normal, the ultrasonic pulse will be excited until time t ₁ . 2. From time _t6 to time t6, the vibration oscillates as shown in Fig. 2. Therefore, with the self-check signal "1" from the self-check switch 8 and the pulse signal from the pulse generating circuit 1, the output of the AND circuit 7 (shown in FIG. 2) is output as a check pulse signal from time t ₂ to time t ₃ . It becomes “1”. And the time t ₃ when the output of the AND circuit 7 is “1”
-t ₂ , the switch 3 becomes conductive, and a part of the waveform shown in FIG. 2 is applied to the connection point between the ultrasonic receiver 4 and the receiving circuit 5. Here, if the ultrasonic receiver 4 is normal, if the ultrasonic pulse is applied for a period from time t ₂ to time t ₃ (as shown in FIG. 2), from time t ₃ to time t ₇ Until then, it makes a sad vibration as shown in Fig. 2. Therefore, if this waveform is input to the receiving circuit 5, and its output is input to the level discrimination circuit 6, and the threshold value is set to A, the level discrimination circuit 6
The output (shown in FIG. 2) is "1" from time _t2 to time _t5 . Further, the pulse generating circuit 1 generates a pulse that becomes "1" at time _t4 shown in FIG. 11, the AND circuit 11 performs a logical product with the "1" output of the level discrimination circuit 6, and the output pulse is input to the OR circuit 12, and the output pulse (shown in FIG. 2, 6) is Appears at time _t3 . This output pulse causes the display circuit 13 to display and generate a normal alarm.

Then the device is working normally and from time t ₈ to time
When the ultrasonic pulse is excited by the pulse generation circuit 1 until t ₉ , if the ultrasonic transmitter 2 is normal, the time from time t ₉ to time t ₁₄ is reduced as shown in Fig. 2. vibrate. Therefore, due to the self-check signal "1" from the self-check switch 8 and the pulse signal from the pulse generating circuit 1, the output of the AND circuit 7 (shown in FIG. 2) becomes "1" from time _t10 to time _t11 . . Then, the switch 3 becomes conductive during the time t ₁₁ - _{t 10} when the output of the AND circuit 7 is "1", and a waveform (shown in FIG. 2 1) is applied to the connection point between the ultrasonic receiver 6 and the receiving circuit 5. Ru. Here, if the ultrasonic receiver 4 is abnormal, for example, if foreign matter is attached to the surface of the ultrasonic receiver 4 or if the ultrasonic receiver 4 is damaged, the time t ₁₁ to t ₁ ' As shown in Fig. ₂ and 3, the waveform 2 shows symptoms such as not having enough vibrations of sadness, and the time is short, or there is no vibration of sadness at all.This waveform is input to the receiving circuit 5, and the output level is further adjusted. When the input is input to the discrimination circuit 6 and the threshold value is set to A, the output of the level discrimination circuit 6 (shown in FIG. 2) is "1" from time _t10 to time _t12 , and the output from the self-check switch 8 is Even if the self-check signal "1" and the pulse generated by the pulse generating circuit 1 (from time _t13 in FIG. 2) are input to the AND circuit 11, no output pulse is output. Also, when the ultrasonic receiver 4 is not connected to the receiving circuit 5, the receiving circuit 5
Since the pulse is not input to the output pulse, no output pulse is output as in the operation described above.

Next, when the device is operating normally and an ultrasonic pulse is excited from the pulse generation circuit 1 from time t ₁₅ to time t ₁₆ , if the ultrasonic transmitter 2 is abnormal (the ultrasonic receiver described above), The same applies if the wave generator 4 is abnormal) The waveform from time t ₁₆ to time t ₁₉ shows that there is not enough vibration vibration, the time is short, or there is no vibration vibration at all, as shown in Fig. 2. Symptoms appear and no output pulse is input to the display circuit 13 either. Therefore, since the display circuit 13 does not issue a normal alarm, it is possible to notify the failure of the device. Furthermore, when the ultrasonic transmitter 2 is not connected to the pulse generating circuit 1, there is no vibration at all after pulse excitation, and no output pulse is output as in the operation described above.

Furthermore, when the signal from the self-check switch 8 is "0" and not during self-check, the output of the inverter circuit 9 becomes "1", so the level discrimination circuit 6
A signal from the sensor is applied to a display circuit 13 via an AND circuit 10 and an OR circuit 12, and an obstacle detection display is performed.

In the above and previous embodiments, the self-check display circuit is shared with the obstacle detection display during normal operation, but it may be separated separately. Although the self-check switch 8 may be operated arbitrarily, for example, when used as an obstacle detection display when reversing a car, it is configured to output a self-check signal "1" for a certain period of time in conjunction with the reverse gear. It may also be possible to automatically check the failure of the device when the vehicle is backed up.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention;
FIG. 2 is a signal waveform diagram at each part in FIG. 1. 1...Pulse generation circuit, 2...Ultrasonic transmitter, 4...
Ultrasonic receiver, 8... Self-check switch, 13
...Display circuit.

Claims (1)

[Scope of Claims] 1. A pulse generating circuit that generates an ultrasonic carrier wave pulse signal, an ultrasonic transmitter that receives the carrier wave pulse signal from the pulse generating circuit and emits an ultrasonic pulse, and the ultrasonic transmitter. There is an ultrasonic receiver that is installed independently of the ultrasonic wave transmitter and receives the ultrasonic reflected waves from the emitted ultrasonic pulses reflected by an object, and an ultrasonic wave receiver that receives the received wave signal of this ultrasonic receiver and increases the An ultrasonic device configured to transmit and receive ultrasonic waves, comprising a receiving circuit that performs reception processing such as width and detection, and a circuit that outputs a check pulse signal after a predetermined time from generation of the carrier pulse signal; a switch provided between the ultrasonic transmitter and the ultrasonic receiver, which becomes conductive upon receiving the check pulse signal; and after the switch becomes conductive, the signal from the ultrasonic receiver reaches a predetermined level or higher; What is claimed is: 1. A failure detection device for an ultrasonic device, comprising: a determining means for determining whether or not the condition continues for a predetermined period of time; and a means for notifying a failure of the ultrasonic device based on a determination result of the determining means.