JPH0669892A - Abnormality detection system in transmitter-receiver for space transmission using ultrasonic signal - Google Patents

Abstract

PURPOSE:To remarkably shorten the time required to detect a transmission disable state and to prevent a mulfunction in the transmitter-receiver for space transmission using the ultrasonic wave. CONSTITUTION:A transmitter 20 converts a transmission signal into the ultrasonic wave and transmits it from an ultrasonic element 5 at the prescribed cycle. The transmitted ultrasonic signal is accepted by an ultrasonic element 5' of a receiver 30 and it is supplied to a pulse reproduction circuit 7 through a reception amplifier 6, reproducing a transmission pulse. When the receiver 30 accepts the ultrasonic signal sent from the transmitter 20, the receiver 30 is switched soon to the transmitter and the pulse signal outputted from a pulse transmission amplifier 9 is sent to a transmission space to receive the reflection wave. A distance comparison discrimination circuit 10 of the receiver 30 discriminates the presence of an obstacle in the transmission space from the time interval between the transmitted pulse signal and the reflection wave, and when the transmission abnormality due to the presence of the obstacle occurs, outputs an abnormal signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting an abnormality in a spatial transmission transmitter / receiver for transmitting signals spatially using ultrasonic waves. In particular, the present invention relates to an obstacle in transmission space that hinders transmission. The present invention relates to an abnormality detection method in a space transmission transmitter / receiver that uses ultrasonic waves and that can detect that a signal cannot be transmitted or a signal error occurs due to the presence of the above.

[0002]

2. Description of the Related Art FIG. 5 is a diagram showing a configuration of a conventional transmitter / receiver for transmitting a spatial signal using ultrasonic waves, where 1 corresponds to a natural oscillation frequency of an ultrasonic element provided in a transmitter 20. An oscillator 2 for generating a signal having a different frequency is a pulse generator 2 for generating a pulse signal having a pulse number or a pulse width corresponding to a signal voltage. As a means for converting the signal voltage into the number of pulses or the pulse width, for example, a well-known V / F converter or a PWM circuit is used.

Reference numeral 3 is an AND gate for passing a signal generated by the oscillator 1 only while the pulse generator 2 is generating a pulse signal, 4 is a transmission amplifier for amplifying the output of the AND gate 3, and 5 is a transmission amplifier 4. It is an ultrasonic element that converts an output electric signal into an ultrasonic signal and transmits the ultrasonic signal.
Reference numeral 5'is an ultrasonic element provided in the receiver 30 for receiving an ultrasonic signal generated by the ultrasonic element 5 of the transmitter 20 and converting it into an electric signal, and 6 is a receiving element for amplifying the output of the ultrasonic element 5 ' An amplifier 7 is a pulse reproduction circuit for reproducing a pulse signal from the output of the reception amplifier 6.

In the figure, when transmitting a signal,
The signal voltage is converted into the number of pulses or the pulse width, and the pulse generator 2 generates a pulse signal corresponding to the signal voltage. The AND gate 3 allows the signal generated by the oscillator 1 to pass while the pulse generator 2 is generating the pulse signal. The output of the AND gate 3 is amplified by the transmission amplifier 4 and given to the ultrasonic element 5. The ultrasonic element 5 converts the output of the transmission amplifier 4 into an ultrasonic signal and transmits the ultrasonic signal.

The transmitted ultrasonic signal is received by the ultrasonic element 5'of the receiver 30, converted into an electric signal and amplified by the reception amplifier 6. The pulse reproduction circuit 7 reproduces the pulse signal from the output of the reception amplifier 6 and outputs it.

[0006]

By the way, in the ultrasonic transmitter / receiver shown in FIG. 5, if there is an obstacle in the transmission space between the ultrasonic element 5 and the ultrasonic element 5 ', signal transmission becomes impossible. Becomes As a method for detecting the above-mentioned signal transmission impossible state, generally, a method of detecting that the pulse has stopped arriving at the receiver and detecting the signal transmission impossible state is used. A predetermined time (for example, a time corresponding to the ultrasonic pulse transmission interval) is required to detect that the incoming call has stopped, and a signal error will occur during the transition period.

The present invention has been made in order to solve the above-mentioned problems, and by making it possible to detect a transmission failure state due to an obstacle or the like within the ultrasonic pulse transmission interval, the detection time of the transmission failure state is detected. It is an object of the present invention to provide an anomaly detection method in a space transmission transmitter / receiver using ultrasonic waves in which the malfunction is prevented and malfunction is prevented.

[0008]

In order to solve the above-mentioned problems, according to the present invention, a transmitter for converting a signal to be transmitted into an ultrasonic signal and transmitting the ultrasonic signal at a predetermined period, and a transmitted ultrasonic signal are received. An abnormality detection method in an ultrasonic transmitter / receiver that is composed of a receiver and performs short-distance spatial signal transmission, and uses the ultrasonic signal reception pause period to switch the receiver to the transmitter and detect an abnormality detection signal. Is transmitted to a transmission space, and a reflected wave is detected by a receiver to detect an abnormality in the transmission space.

[0009]

According to the present invention, when the ultrasonic signal transmitted by the transmitter is received, the receiver is immediately switched to the transmitter to transmit the abnormality detection signal to the transmission space and the reflected wave is detected by the receiver. Since it detects abnormalities in the transmission space by means of, it is possible to detect transmission abnormalities due to the presence of obstacles in the transmission space within the ultrasonic transmission cycle, significantly shortening the detection time of the transmission disabled state, and malfunctioning. Can be prevented.

[0010]

FIG. 1 is a diagram showing an embodiment of the present invention. In the figure, the same components as those in the conventional example shown in FIG. 5 are designated by the same reference numerals, 1 is an oscillator for generating a signal having a frequency matching the natural oscillation frequency of the ultrasonic element, and 2 is a signal voltage. A pulse generator for generating a pulse signal having a pulse number or a pulse width corresponding to 3 is an AND gate for passing a signal generated by an oscillator 1 only while the pulse generator 2 is generating a pulse signal, and 4 is an AND gate A transmission amplifier 5 for amplifying the output of 3 is an ultrasonic element.

Further, 5'receives an ultrasonic signal generated by the ultrasonic element 5 of the transmitter 20 and converts it into an electric signal, and at the same time, converts an electric signal output by the transmission amplifier 9 into an ultrasonic signal and converts the ultrasonic signal into an ultrasonic signal. , 6 is a receiving amplifier for amplifying the output of the ultrasonic element 5 ', 7 is a pulse reproducing circuit for reproducing a pulse signal from the output of the receiving amplifier 6, and 8 is M
Analog switch using OS-FET, or
A transmission / reception switching circuit including a mercury relay, a reed relay, and a relay having mechanical contacts, 9 is a pulse transmission amplifier that amplifies a transmission pulse for obstacle detection, and 10 is a transmission pulse for obstacle detection and its reflected wave. It is a distance comparison / discrimination circuit that discriminates the presence of an obstacle from a time interval.

Next, the operation of the apparatus of the embodiment shown in FIG. 1 will be described. At the time of transmission, in the transmitter 20, the pulse generator 2 generates a pulse signal corresponding to the signal voltage, and supplies the pulse signal to the transmission amplifier 4 via the AND gate 3 as in the conventional example. The output of the AND gate 3 is amplified by the transmission amplifier 4, converted into an ultrasonic signal by the ultrasonic element 5, and transmitted.

FIG. 2 is a diagram showing a transmission signal transmitted from the transmitter 20. The transmission signal transmitted from the ultrasonic element 5 of the transmitter 20 is oscillated by the oscillator 1 as shown in FIG. It consists of a pulse train obtained by pulse-width modulating an oscillation signal of the resonance frequency fo, and the pulse train is transmitted at intervals of the period T and received by the receiver 30. When the transmission signal shown in FIG. 2 is received by the receiver 30, the reception signal is given to the reception amplifier 6 via the transmission / reception switching circuit 8 and amplified.
The pulse signal of the amplified signal is reproduced in the pulse reproduction circuit 7. Immediately after the reception, the transmission / reception switching circuit 8 of the receiver 30 is switched to the transmission side, and the pulse transmission amplifier 9 is activated to generate a pulse signal for obstacle detection from the pulse transmission amplifier 9 to generate an ultrasonic element. Send from 5 '.

After the transmission, the transmission / reception switching circuit 8 is again provided.
Is switched to the receiving side, the reflected wave is received by the ultrasonic element 5 ′, amplified by the receiving amplifier 6, and given to the distance comparison / determination circuit 10. FIG. 3 is a diagram showing a time chart of the reception signal, the obstacle detection pulse signal and the reflected wave thereof, in which FIG. 3A is a reception pulse received by the receiver 30, and FIG. An obstacle detection pulse transmitted from the device 30, (c) shows a reflected wave when there is no obstacle in the transmission space, and (d) shows a reflected wave when there is an obstacle in the transmission space.

As shown in the figure, when the receiver 30 receives the received pulse, the pulse transmission amplifier 9 is immediately activated, and the ultrasonic element 5'transmits a pulse for obstacle detection. The transmitted pulse is reflected by the transmitter 20 when there is no obstacle in the transmission space, and is reflected by the obstacle when there is an obstacle in the transmission space, and the reflected wave is the receiver. It is received by 30 ultrasonic elements 5 '.

The reflected wave received by the ultrasonic element 5 ′ is given to the distance comparison / determination circuit 10 via the transmission / reception switching circuit 8 and the reception amplifier 6. Here, the distance between the transmitter 20 and the receiver 30 shown in FIG. 1 is L (m), the velocity of the sound wave is vo (m / sec), and the distance from the receiver 30 to the obstacle when there is an obstacle is Lx. Assuming that (m), as shown in FIG. 4, if there is no obstacle after the transmission pulse for obstacle detection is generated from the ultrasonic element 5 ′, 2 × L / vo
The reflected wave is received after (sec), and when there is an obstacle, the reflected wave is received after 2 × Lx / vo (sec).

Since the distance L between the transmitter and the receiver is known,
If 2 × L / vo is set in the distance comparison / discrimination circuit 10, the presence of an obstacle can be easily detected from the received pulse (a). As described above, according to the present embodiment, the obstacle existing in the transmission space can be detected within the reception pulse period T, and there is no need to wait until the arrival of the next transmission pulse. It is possible to prevent a malfunction caused by a delay in detecting the presence.

FIG. 4 is a diagram showing an embodiment in which the present invention is applied to a ground fault detection of a three-phase power source. In FIG.
0 and 70 are currents IU, IV, and IW of three-phase and three-phase
, 80, 90, 100 are receivers for receiving the transmission signals from the transmitters, and receivers 80, 9
The three-phase currents received by 0 and 100 are added by the three-phase synthesis amplifier 45 to obtain the zero-phase current Io, and the ground fault is detected.

In the figure, transmitters 50, 60 and 70 have the same structure, and 41 is a current / current for converting a current into a voltage.
A voltage converter 42 is V / which converts the voltage value converted by the current / voltage converter 41 into a frequency signal proportional thereto.
An F converter, 43 is a transmission amplifier, and 5 is an ultrasonic element that converts an electric signal into an ultrasonic wave and transmits the ultrasonic wave. Further, the receivers 80, 90, 100 have the same configuration, and 5 ′ receives the ultrasonic signal generated by the ultrasonic element 5 of the transmitter 50 and converts it into an electric signal, and at the same time, outputs the electric signal output by the transmission amplifier 9. An ultrasonic element that converts a signal into an ultrasonic signal and transmits the ultrasonic signal, 6 is a reception amplifier that amplifies the output of the ultrasonic element 5 ′, 7 is a pulse reproduction circuit that reproduces a pulse signal from the output of the reception amplifier 6, Reference numeral 8 is a transmission / reception switching circuit, 9 is a pulse transmission amplifier for amplifying a transmission pulse for obstacle detection, and 10 is a distance comparison / discrimination circuit for discriminating the presence of an obstacle from the time interval between the transmission pulse for obstacle detection and its reflected wave. , 44 are F / V converters for converting the frequency of the pulse signal reproduced by the pulse reproduction circuit 7 into a voltage signal.

Reference numeral 45 denotes the above-mentioned three-phase synthesizing amplifier, which sums the outputs of the receivers 80, 90 and 100 to obtain a zero-phase current, and at the same time the receivers 80, 90 and 100 detect abnormalities such as the presence of obstacles. When this is detected and the distance comparison / determination circuit 10 produces an output, the output is locked. Next, the operation of the embodiment shown in FIG. 4 will be described. The currents IU, IV and IW of the three phases and the respective phases detected by the current measuring device such as CT are transmitted to the transmitters 50 and 6 respectively.
It is converted into a voltage signal by the 0/70 current / voltage converter 41, and converted into a frequency signal by the V / F converter 42. The signal converted into the frequency signal by the V / F converter 42 is amplified by the transmission amplifier 43, converted into the ultrasonic signal by the ultrasonic element 5, and transmitted.

The transmitted ultrasonic signals are received by the receivers 80, 9
The signals are received by the ultrasonic elements 5'of 0, 100, and given to the reception amplifier 6 via the transmission / reception switching circuit 8 and amplified as described in the embodiment of FIG. A pulse signal is regenerated in the pulse regenerating circuit 7 from the amplified reception signal, converted into a voltage signal by the F / V converter 44, and given to the three-phase synthesizing amplifier 45. The three-phase synthesis amplifier 45 synthesizes the phase currents IU, IV, IW received by the receivers 80, 90, 100 to obtain a zero-phase current.

Immediately after the receiver 80, 90, 100 receives the transmission signal, the transmission / reception switching circuit 8 of the receiver 80, 90, 100 is switched to the transmission side, and the pulse transmission amplifier 9 is activated to perform pulse transmission. A pulse signal for obstacle detection is generated by the amplifier 9 and transmitted from the ultrasonic element 5 '. Then, after the transmission, the transmission / reception switching circuit 8 is switched to the reception side again, the reflected wave is received by the ultrasonic element 5 ′, amplified by the reception amplifier 6, and the distance comparison / determination circuit 1 is transmitted.
Give to 0.

Here, there are obstacles and the like in the transmission space of the transmitters 50, 60 and 70 and the receivers 80, 90 and 100,
The reflected wave as shown in FIG.
When detected by either 90 or 100, the distance comparison / discrimination circuit 10 generates an output and locks the output of the three-phase synthesis amplifier 45. In the ground fault detection method that detects the ground fault by the zero-phase current, when an abnormal state occurs in the transmitter / receiver of one of the three phases, the zero-phase current is generated even if the ground fault does not occur. However, in the present embodiment, the three-phase current IU,
When a failure occurs in either the transmitter or the receiver for transmitting IV and IW, the output of the three-phase synthesis amplifier 45 is locked within the pulse transmission cycle T shown in FIG. Can be locked, and the abnormality detection time can be greatly shortened compared to the conventional one.

In the anomaly detection time in this embodiment, when the spatial propagation distance is 30 cm, the speed of the sound wave is 340 m /
Since it is sec, 0.3 × 2/340 = about 1.8 ms
The abnormality detection output can be obtained by ec, and the above-mentioned malfunction can be prevented. In the spatial transmission method using ultrasonic waves shown in the above embodiment, the transmission time of the signal is limited to the detection time t = 2 × L / vo of the reflected wave of the ultrasonic wave, and the sound velocity is slow at 340 m / sec. The frequency of the signal to be handled is about 50/60 Hz, and the distance between the transmitter and the receiver is limited to within 1 m.

Further, in the above embodiment, an example in which transmission and reception are performed by one element as the ultrasonic element on the receiving side has been shown, but the present invention is not limited to the above embodiment, and the It is also possible to use separate ultrasonic elements for reception.

[0026]

As is apparent from the above description,
In the present invention, by utilizing the reception pause period of the ultrasonic signal, the receiver is switched to the transmitter, the abnormality detection signal is transmitted to the transmission space, and the reflected wave is detected by the receiver, whereby in the transmission space. Since the abnormality detection is performed, the abnormal state in the transmission space can be detected in a short time, and the malfunction due to the transmission abnormality can be prevented.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a transmission signal transmitted from a transmitter.

FIG. 3 is a diagram showing a time chart of a reception signal and an abnormality detection signal.

FIG. 4 is a diagram showing an embodiment in which the present invention is applied to ground fault detection.

FIG. 5 is a diagram showing a conventional example.

[Explanation of symbols]

 1 oscillator 2 pulse generator 3 AND gate 4,43 transmission amplifier 5,5 'ultrasonic element 6 reception amplifier 7 pulse regeneration circuit 8 transmission / reception switching circuit 9 pulse transmission amplifier 10 distance comparison / discrimination circuit 41 current / voltage converter 42 V / F converter 44 F / V converter 45 Three-phase synthesis amplifier

Claims (1)

[Claims] 1. A transmitter for converting a signal to be transmitted into an ultrasonic wave signal and transmitting the ultrasonic wave signal at a predetermined cycle, and a receiver for receiving the transmitted ultrasonic wave signal. In the abnormality detection method in the ultrasonic wave transmitter / receiver, the receiver is switched to the transmitter and the abnormality detection signal is transmitted to the transmission space by using the reception pause period of the ultrasonic signal, and the reflected wave is detected by the receiver. An abnormality detection method in a space transmission transmitter / receiver using ultrasonic waves, characterized by performing abnormality detection in a transmission space.