JPH0786530B2 - Underwater detector device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a transducer of an underwater detector having improved directional characteristics. This transmitter / receiver emits a detection signal so that the signal strength within a predetermined angle can be made substantially constant, and can also receive a signal coming from within a predetermined angle with substantially constant sensitivity.

[Conventional technology]

The directional characteristic of the conventional transducer is shown in FIG. 5, in which the detection signal cannot be emitted so that the signal strength within the directional angle is constant, and the signal arriving from within the directional angle is constant. I could not receive because of the sensitivity. In the conventional wave transmitter / receiver, for example, a detection signal having the same amplitude is applied over the entire surface of the electrode of the vibrator.

[Problems to be solved by the invention]

When the conventional transducer having the directional characteristics as shown in FIG. 5 is used in, for example, an underwater detection device, when the reflected signal from the detected object captured by the transducer is displayed on the display. The area around the image is not clearly displayed and is unclear. Further, when the amplification factor for amplifying the captured reflected signal is changed, the size of the image changes, and the size of the detected object cannot be accurately known.

[Means for solving problems]

A plurality of vibrators each having a pair of electrodes parallel to the axis are arranged on an axis perpendicular to the beam transmission / reception direction, and a plurality of secondary windings of a transformer are connected to the electrodes of the vibrators. The number of windings considering the polarity of each secondary winding connected to each of the vibrators is a function of the position on the axis of each vibrator with the center of the vibrator row as the origin, A value that is determined by a sinusoidal curve that has an antinode in the center of the transducer row, nodes at both ends of the transducer row on the axis, and at least two points in each end, and is inversely proportional to the distance from the center of the transducer row. When a high-frequency signal is applied to the primary winding of the transformer, the transmission beam formed by combining the outputs from the above-mentioned transducers and transmitted is substantially uniform in the pointing direction. Is formed on the When the generated electrical signals are combined and output to the primary winding of the transformer, the directional characteristics integrally formed by each transducer are configured to be approximately uniform in the beam receiving direction. It is a transmitter / receiver of a detection device.

〔Example〕

 FIG. 1 shows an embodiment of the present invention.

FIG. 2 shows the relationship between the signal applied to the electrodes of the vibrator shown in FIG. 1 or the signal extracted from the electrodes of the vibrator and the directional characteristics of the vibrator.

FIG. 3 shows another embodiment of the present invention.

FIG. 4 shows a signal supplied to the oscillator shown in FIG. 3 or a signal extracted from the oscillator.

In FIG. 1, piezoelectric vibrators 1, 2, 3, and 4 have the same specifications and are arranged on a straight line at equal intervals. Transformer 5
A pulse signal whose carrier frequency is amplitude-modulated with a constant amplitude of, for example, 50 KHz is supplied to the primary side. One end of the secondary winding 6 of the transformer 5 is connected to the upper electrodes 8 of the vibrators 2 and 3,
9 is connected to the other end, and the other end is the upper electrode of vibrators 1 and 4.
7, 10 and their intermediate terminals 16 are commonly connected to the lower electrodes 11, 12, 13, 14 of the vibrators 1, 2, 3, 4.

FIG. 2 (A) shows the transducers 1, 2, 3, 4 that compose the transducer.
And the amplitude signal applied thereto, and FIG. 2 (B) shows the directional characteristics of the transceiver. In FIG. 2 (A), the transducers 1, 2, 3, 4 having a pair of electrodes parallel to the x-axis are symmetrical with respect to the y-axis on the x-axis that is perpendicular to the beam transmission / reception direction. It is shown that they are arranged at equal intervals so that A signal having an amplitude determined by the illustrated signal curve is applied to the vibrators 1, 2, 3, 4 arranged in this way.
This signal curve is represented by y = sin x / x,
It is a sine wave curve having an amplitude inversely proportional to the distance from the origin, which is the center of the transducer rows 1 to 4. Here, x is the axis with the circumferential angle as the unit, but 20,21,22,23 points are l /
The points correspond to λ, 2l / λ, −l / λ, −2l / λ. Here, 1 is the length of the electrode of the vibrator, and λ is the wavelength. l / λ is a dimensionless number that represents the size of the oscillator, which is a conventional display that does not change with frequency and shows how many times the wavelength.

The signal curve of y = sin x / x has an antinode on the y-axis and in the center of the transducers 1 and 4, and the boundary between the transducers 1 and 2 and the transducers 3 and 4 (point 2
It has nodes at both ends (corresponding to points 21 and 23) of the vibrators 1 and 4. In addition, x is the unit of the circumferential angle, l / λ is a dimensionless number, and the scale is different.
The relation between x and l / λ is y = sin x / x = sin [2π (λ / 2l)
x ′] / [2π (λ / 2l) x ′]. For example, when l / λ is substituted for x ′, y = sin π / π = 0, and a node is provided at a position corresponding to l / λ.

After all, in comparison with FIG. 1, the reference amplitude signal a is supplied from the intermediate terminal 16 of the transformer 5 to the electrodes 11, 12, 13, 14 of the vibrator. A signal having the amplitude of b in the signal curve is supplied to the electrodes 8 and 9 of the vibrators 2 and 3, and a signal having the amplitude of c in the signal curve is supplied to the electrodes 7 and 10 of the vibrators 1 and 4. That is, as shown in FIG. 1, the connection relationship between the vibrators 1, 2, 3, 4 and the secondary winding 6 is such that the positive or negative polarity is distributed and the amplitude is determined by the coil winding value. It has become.

As a result, each of the transducers 1, 2, 3, 4 is supplied with an approximation of the signal curve shown in the figure, and the intensity of the signal emitted from the transducer is substantially constant within the predetermined angle θ ₀ , that is, It was also confirmed in an experiment that the directional characteristics as shown in FIG. The angle θ ₀ is calculated by
The directivity angle formed by 2, 3 and 4 is shown. Further, the conversion from the amplitude signal of FIG. 2 (A) to the directivity characteristic of FIG. 2 (B) is performed through the Fourier transform. If the amplitude signal of y = sin x / x is within the predetermined angle θ ₀ . The rising and falling edges of the directional characteristic are sharp, and the directional characteristic becomes substantially uniform within a predetermined angle θ ₀ .

Next, the case of receiving an incoming signal will be described. Oscillator
When incoming signals of the same amplitude are received from 1, 2, 3, and 4, a signal of amplitude b shown in FIG. 2 (A) is received on the primary side of the transformer 5 based on the signals captured by the transducers 2 and 3. Winding 15
To the primary side 15 of the transformer 5 based on the signals sent to the transducers 1 and 4 and captured by the transducers 1 and 4.
Is transmitted to the primary side of the transformer 5 based on the output signals of the electrodes 11, 12, 13, 14 of each transducer. As a result, the incoming signal captured by the received beam having the directional characteristics shown in FIG. 2B is output from the primary side of the transformer 5.

In FIG. 3, piezoelectric vibrators 30 to 37 have the same specifications and are arranged on a straight line at equal intervals. To the primary side of the transformer 38, a pulse signal whose carrier frequency is, for example, 50 KHz and whose amplitude is modulated with a pulse having a constant amplitude is supplied. One end of the secondary winding 39 of the transformer 38 is connected to the upper electrodes 43 and 44 of the vibrators 33 and 34, the other end is connected to the upper electrodes of the vibrators 32 and 35, and the intermediate terminal 60 is a vibrator. The intermediate terminals 61 are connected to the upper electrodes of 31 and 36, the intermediate terminals 61 are connected to the upper electrodes of the transducers 30 and 37, and the other intermediate terminals 62 are the lower electrodes 50 to 37 of the transducers 30 to 37 constituting the transducer. Commonly connected to 57.

The signal curve shown in FIG. 4 is represented by sin x / x. 70,71,72,73,74,75,76,77 are l / λ, 2l / λ,
The points correspond to 3l / λ, 4l / λ, −l / λ, −2l / λ, −3l / λ, −4l / λ. y = sin x / x has an antinode on the y-axis and in the center of the oscillators 30, 31, 32, 35, 36, 37, and the oscillators 30, 31 and the oscillators 31, 32 and 32 , 33 and oscillators 34,35 and oscillators 35,36 and oscillators 36,37 (points 76,75,74,70,71,72
Corresponding) and both ends of the vibrators 30 and 37 (corresponding to points 77 and 73).

After all, in comparison with FIG. 3, the reference amplitude signal a is supplied from the intermediate terminal 62 of the transformer 38 to the lower electrodes 50 to 57 of the vibrators 30 to 37. A signal having an amplitude of b in the signal curve is supplied to the upper electrodes of the oscillators 33 and 34, a signal having an amplitude of c in the signal curve is supplied to the upper electrodes of the oscillators 32 and 35, and an amplitude of d in the signal curve is supplied. Is supplied to the upper electrodes of the oscillators 31 and 36, and the signal having the amplitude of e in the sinusoidal curve is supplied to the upper electrodes of the oscillators 30 and 37. That is, as shown in FIG. 3, the connection relationship between the vibrators 30 to 37 and the secondary winding 39 is such that the positive or negative polarity is distributed and the amplitude is determined by the coil winding value. .

As a result, each of the transducers 31 to 37 is supplied with an approximation of the signal curve shown in the figure, and as shown in FIG.
It is possible to obtain a directional characteristic that can make the intensity of the signal emitted from the wave transmitter / receiver substantially constant within the predetermined angle θ ₀ . According to this embodiment, it is possible to obtain a directional characteristic in which rising and falling are more steep as compared with the directional characteristic shown in FIG.

Next, the case of receiving an incoming signal will be described. When the incoming signals of the same amplitude are received by each of the transducers 30 to 37 constituting the transceiver, the signal of the amplitude b shown in FIG. 4 is transferred to the transformer 38 based on the signals captured by the transducers 33 and 34. Based on the signals sent to the primary winding 80 and received by the oscillators 32 and 35, the signal of the amplitude c in the same figure is obtained, and based on the signals captured by the oscillators 31 and 36, the amplitude of the same figure is shown. the signal having the amplitude d in the figure based on the signals received by the transducers 30 and 37,
Based on the output signals of the lower electrodes 50 to 57 of 30 to 37, the signal of the amplitude a in the figure is transmitted to the primary side of the transformer 38. As a result, the incoming signal captured by the received beam having the directional characteristics shown in FIG. 2B is output from the primary side of the transformer 38.

In this embodiment, eight piezoelectric vibrators are used, but the number is not limited to this, and an even number of four or more vibrators may be used. Then, at the time of transmission, a signal having an amplitude determined by the position of each transducer and the signal curve of sin x / x may be supplied, and at the time of reception, a signal having these amplitudes may be taken out from each transducer.

When a signal of a predetermined amplitude is applied to or taken out from each of the vibrators 30 to 37 shown in FIG.
And 34, a signal having the amplitude h shown in FIG. 4 is supplied to the oscillators 32 and 35, and a signal having the amplitude i shown in FIG.
A signal having an amplitude j is supplied to 35 and 37 via a transformer to form a transmission beam, or conversely, a signal having an amplitude h, i or j is taken out from a corresponding predetermined oscillator 30 to 37 and synthesized. By doing so, it is possible to form a received beam. In this case, more ideal directional characteristics can be obtained as compared with the one shown in FIG.

In the above example, the electrostrictive oscillator was used,
Even if a magnetostrictive vibrator is used, the same purpose can be achieved and the same effect can be obtained.

〔The invention's effect〕

As described above, in the transducer of the underwater detection apparatus of the present invention, the detection signal is emitted so that the signal strength within the directivity angle is substantially constant, and the signal coming from within this directivity angle is constant. Since the signal is received with the sensitivity of 1, even when the reflection signal from the object to be detected is displayed on the display, the periphery of the image is not unclear and the size can be accurately known.

Furthermore, with a simple configuration in which one end and the other end of the secondary winding of the transformer and the intermediate terminal are connected to the electrodes, the amplitude of the amplitude can be obtained at the other end or one end of the intermediate terminal. Since it is possible to receive the incoming signal so that the signal strength is substantially constant as in the case of the detection signal emission in which the signal strength is substantially constant, a high-performance transceiver can be manufactured at low cost. .

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 2 is a diagram showing the relationship between the signals applied to the electrodes of the vibrator shown in FIG. 1 or the signals taken out from the electrodes of the vibrator and the directional characteristics of the vibrator. FIG. 3 shows another embodiment of the present invention. FIG. 4 is a diagram showing a signal supplied to the oscillator shown in FIG. 3 or a signal extracted from the oscillator. Fifth
The figure shows the directional characteristics of the conventional transducer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-61-184091 (JP, A) JP-A-48-40393 (JP, A) JP-A-55-11271 (JP, A) JP-A-57- 168232 (JP, A) JP-B 4-26278 (JP, B2) JP-B 4-81400 (JP, B2)

Claims (1)

[Claims] 1. A plurality of vibrators each having a pair of electrodes parallel to the axis are arranged on an axis perpendicular to the beam transmitting / receiving direction, and a plurality of transformers are provided on the electrodes of the vibrator. A secondary winding is connected, and the winding number considering the polarities of the secondary windings connected to the respective oscillators is on the axis of each oscillator with the center of the oscillator row as the origin. A sinusoid that has an antinode at the center of the transducer row, nodes at both ends of the transducer row on the axis, and at least two points at both ends as a function of position, and is inversely proportional to the distance from the center of the transducer row. When the high frequency signal is applied to the primary winding of the transformer, the transmission beam formed and transmitted by combining the outputs from the above-mentioned oscillators is set to a value determined by the wave curve, It is formed almost uniformly in the pointing direction, and the vibrator receives vibration. When the electrical signals generated by each transducer are combined and output to the primary winding of the transformer, it is necessary that the directional characteristics integrally formed by each transducer be substantially uniform in the beam receiving direction. Characteristic underwater detector device.