JPS61218968A - Ultrasonic wave azimuth sensor - Google Patents

Abstract

PURPOSE:To adjust the phase shift due to the fitting accuracy of a vibrator by providing a sensor, which compares phases of ultrasonic wave signals of respective ultrasonic wave vibrators receiving an ultrasonic wave and detects the incident azimuth of the ultrasonic wave, with a phase adjusting circuit for adjusting initially a phase difference. CONSTITUTION:The ultrasonic wave vibrators 1 and 2 receive the incident ultrasonic wave, and amplifier circuits 3 and 4 and waveform shaping circuits 5 and 6 amplify and waveform-shape it, after which the phase adjusting circuits 10 and 11 are provided to obtain outputs V01 and V02. The circuits 10 and 11 are constituted of a comparator composed of a resistance R, a capacitor C and an operational amplifier OP, for instance. In case the phase shift caused by the fitting accuracy of the vibrators 1 and 2 is present even if the ultrasonic wave makes incident in the right facing direction, the phase shift comes to zero by the initial adjustment. Thus the normal phase difference can be detected in accordance with the incident azimuth.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an ultrasonic azimuth sensor that detects azimuth using ultrasonic waves.

[Background technology 1] Conventionally, ultrasonic azimuth sensors convert ultrasonic waves into electric waves using multiple transducers, and detect the phase difference of these ultrasonic signals to determine the direction of the propagating ultrasonic waves. In the example shown in Figure 13, two ultrasonic transducers (11,
+21 receives the incident ultrasonic wave and sends it to the amplification circuit (3
), +4+ and the waveform shaping circuits (6), (6) provide the amplified and waveform shaped outputs vOI' and ■OI,
The phase difference between vOζ and Voj can be obtained based on the incident azimuth, and the azimuth can be detected. However, as shown in Figure 5, the ultrasonic transducers +1) and +2
Installation accuracy when 1 is installed, vibrator housing (
Due to the dimensional accuracy of 7), and the accuracy of the mounting position or dimensions of the vibration surfaces (8) of the ultrasonic transducers (1) and (2), there may be a phase difference even if the incident direction is directly in front of you. It will not be zero, but will have a deviation of Δφ as shown in FIG. Furthermore, as shown in Fig. 6, an ultrasonic transducer (l
When a mask (9) for shielding or detecting the incidence of ultrasonic waves is provided on the front surface of (2), the above-mentioned problems arise depending on the accuracy of its mounting and dimensions.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ultrasonic azimuth sensor that can detect accurate azimuth by allowing initial adjustment of phase shifts caused by mounting accuracy of an ultrasonic transducer.

[Disclosure of the invention]

In Figure 1, the incident ultrasonic wave is transmitted through an ultrasonic transducer (
1), (receive at
) and waveform shaping circuit (51, (61) after amplification and waveform shaping, a phase adjustment circuit +1011 (tt) is provided to obtain outputs Vol and Vol. Phase adjustment circuit (II
# (11) is the resistance R1 as shown in WI2 diagram, for example.
It can be configured by a comparator using a capacitor 01 and an operational amplifier OP. By providing the phase adjustment circuit uco't (o), even if ultrasonic waves are incident from directly in front, even if there is a phase shift caused by the mounting accuracy of the ultrasonic transducers (1, (21), By performing initial adjustment, the phase shift can be made zero, and normal phase difference detection according to the incident azimuth can be performed from vo, svo*Ic.

[Effects of the Invention] As described above, the present invention provides a phase adjustment circuit that initially adjusts the phase difference, so it is possible to initially adjust the phase shift caused by the installation accuracy of the ultrasonic transducer, and it is possible to detect accurate orientation. It is effective.

[Brief explanation of drawings]

FIG. 1 is a block circuit diagram of an embodiment of the present invention, FIG. 2 is a circuit diagram of the phase adjustment circuit same as above, FIG. 3 is a circuit diagram of a conventional example, FIG. 4 is an operation time chart of same as above, and FIG. The figure is a front view of an example of the attached state of the ultrasonic transducer same as the above, and FIG. 6 is a front view of another example of the same as the above. +1) , (ri...ultrasonic vibrator, screamt H...
Phase Adjustment Circuit Agent Patent Attorney Ishi 1) Chief Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] (1) An ultrasonic direction in which the direction in which the ultrasonic wave is incident is detected by receiving the ultrasonic wave with a plurality of ultrasonic transducers and comparing the phase difference between the ultrasonic signals of each of the ultrasonic transducers. An ultrasonic azimuth sensor characterized in that the sensor is provided with a phase adjustment circuit for initially adjusting a phase difference.