JPH0321495Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a beam forming device that can change the beam direction and beam width of the transmitting and receiving beam of a transducer for a scanning sonar or a fish finder. It is.

(Prior Art) In conventional scanning sonar and fish finders, the direction of the sound wave beam can be changed in order to facilitate the detection of fish schools.

As shown in FIG. 3, the conventional beam direction variable means arranges a plurality (n) of transducers A _i (i=1 to n) in a straight line at equal intervals L, and each transducer A It is equipped with a phase shifter that varies the phase of the excitation signal of _i , for example, at an angle θ with respect to the normal to vibrator _A1.
When forming _a directional beam in the direction of It is sufficient to shift the phase by φ _i shown, and thereby the directional beam can be directed in the desired θ direction.

φ _i =2πL (n-1)/λ・sinθ…(1) (λ: wavelength of excitation signal) φ ₁ =0 φ ₂ = (2πL/λ)・sinθ φ ₃ =φ ₂ ×2 φ _o =φ ₂ × (n-1) (Problem to be solved by the invention) However, with the above conventional beam forming means, the directional beam width in the θ direction is determined by the arrangement of the transducers, so it is difficult to vary the beam width. It's impossible.

Generally, in this type of device, the directional beam width is set to be narrow in order to clearly capture a school of fish, and as a result, in the case of a school of fast-moving fish, the school of fish will deviate from the directional width, making accurate tracking and detection impossible. There is this inconvenience. In order to avoid this inconvenience, it is possible to reduce the number of oscillators A _i to widen the directivity width, but since the directivity width is determined by the number of oscillators A _i , it is difficult to change it arbitrarily. Furthermore, if the number of oscillators A _i is reduced, the area of the beam transmission/reception surface becomes smaller, resulting in a problem in that the wave transmission/reception ability decreases.

The present invention was made in consideration of the above-mentioned conventional problems, and its purpose is to provide a highly reliable, simple and small-scale configuration that can direct a directional beam in a desired direction and widen the beam width. An object of the present invention is to provide a beam forming device that can be easily narrowed.

(Means for solving the problems) In order to achieve the above object, the present invention is configured as follows. In other words, the present invention includes a pointing direction command means for giving a phase command for variably setting the beam pointing direction to the excitation signal to each of the plurality of arrayed transducers, and a beam pointing width to the excitation signal of each vibrator. In a beam forming device, the beam forming device is provided with a pointing width commanding means for giving a phase command for variably setting; a storage means storing initial phase data of; a pointing direction and pointing width switching setting section; and an excitation signal for each transducer corresponding to the pointing direction and pointing width set by the switching setting section. A multi-digit binary counter that receives initial phase data from a storage means, is preset to a counted state by a count value corresponding to the initial phase data, and starts counting from the preset value, and the most significant digit is A beam forming apparatus is characterized in that it has a plurality of presettable counters that output rectangular wave signals corresponding to logic 1 and logic 0 to a transmission amplifier for each transducer.

(Function) Generally, when changing the beam pointing direction, it is sufficient to shift the phase of the excitation signal of each vibrator according to the above-mentioned equation (1), and by doing so, the beam can be emitted in any direction. can.

On the other hand, the width of the beam can be changed by applying a phase shift to the excitation signal of each vibrator so that each vibrator becomes equivalent to being arranged on the circumference of a radius of curvature R. That is, for example, the fourth
As shown in the figure, the oscillators arranged on the right side of the center line C are A _Ri and the oscillators arranged on the left side are A _Li , and from the center line C, each oscillator A _Ri and A _Li
If the distance from the oscillator A _Ri to the oscillator A _Li is D _i , then the phase φ of each oscillator A _Ri and the oscillator A _Li must be set to _LRo (the phase for the oscillator A _Ri on the right side of the center line C is φ _Ro , and the phase for the oscillator A _Li on the left side is φ _Lo ), (where λ is the wavelength of the excitation signal). That is, by making the phase shift as described above, each of the oscillators A _Ri and A _Li becomes equivalent to the case where they are arranged on the circumference of the radius of curvature R, thereby making it possible to widen the beam directivity width. In this case, by varying the size of the radius of curvature R, the width of the beam in the paper direction can be set arbitrarily.

Furthermore, by simultaneously operating the phase displacement that determines the pointing direction and the phase displacement that determines the beam width, the effects of both displacements are synergized, and as shown in Figure 5, the beam beam direction is tilted by θ, and the beam width is This makes it possible to emit a wide beam.

In the present invention, by setting the desired pointing direction and pointing width in the pointing direction and pointing width switching setting section, the storage means in which excitation signal phase data corresponding to each pointing direction and each pointing width is stored. By reading out the initial phase data for each transducer corresponding to the set directivity direction and paper direction width, and presetting the clock count value of the presettable counter corresponding to each transducer based on this initial phase data. , a rectangular wave signal of a predetermined frequency having a phase shift according to the initial phase data is obtained from the presettable counter.

The presettable counter changes the frequency of the input clock signal to 1/2, 1/4, 1/8...
It is a binary counter that obtains a rectangular shape by dividing the frequency as follows.

The difference from a simple frequency divider or counter is that the clock can be set (preset) to the same state as a predetermined number of counts.

Hereinafter, a case where the output is a rectangular wave with a frequency divided by 1/32 will be briefly explained with reference to FIG. 6.

Now, if the preset value is 0 for the clock input shown in Figure a, a rectangular wave output as shown in Figure f will be obtained. On the other hand, if the preset value is 5,
The output will also start from a state where the clock count has already advanced to 5, so the output will be like the output g.

Similarly, if you set the preset value to 11, the output will be h, and if you set the preset value to 20, the output will be i.
become that way.

In this way, the phase of the output rectangular wave can be changed by the preset value.

This rectangular wave signal is filtered by the corresponding transmitting amplifier to approximate a sine wave, amplified to a required level, and supplied to the corresponding vibrator to excite the vibrator.

Since one presettable counter is provided for each vibrator, the excitation phase can be changed for each vibrator.

As a result, a beam with the set directivity width is obtained in the set directivity direction.

The beam forming apparatus of the present invention is characterized in that it attempts to change the beam direction and beam width by controlling the preset value of the presettable counter provided for each vibrator.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 shows a block configuration showing an embodiment of the present invention, and a storage element such as a ROM (ROM) 1 has a variable directivity direction and beam width for each vibrator A _i (i=1 to n). Contains phase data.

Note that in this example, for convenience of explanation, a vibrator is not used.
A case where the number of A _i is 8 (n=8) will be explained. Since the first ROM 1 has eight oscillators A _i , three bits are used as the lower address. Also,
If the beam direction θ is to be varied up to 60° in steps of 1°, for example, 6 bits of capacitance are used. Furthermore, when changing the directivity width to, for example, four types, 2 bits are used, so ROM 1 as a whole
It has an 11-bit capacity configuration, and phase data φ〓 _i (i = 1 to n) of the excitation signal for each vibrator A _i is stored in correspondence to each beam direction θ and specified width. .

The beam pointing direction θ is specified by setting the setting knob of the first volume 2, which serves as a pointing direction switching setting section, to a desired angular position. This setting signal is input to the ROM 1 via the first A/D converter 3, and addresses each vibrator A _i with a phase corresponding to the setting directivity direction θ.

Similarly, the pointing width, that is, the beam width, is specified by switching the setting knob of the second volume 4, which serves as the pointing width switching setting section. This switching signal is then passed through the second A/D converter 5 to the ROM 1.
and address the excitation signal for each transducer A _i with the phase corresponding to the set beam width.

In this case, if the beam pointing direction and beam width are specified at the same time, each excitation signal will be addressed with the sum of the phase of the pointing direction and the phase of the beam width.

On the other hand, a plurality of presettable counters P _i (i=1 to n) are arranged in one-to-one correspondence with each vibrator A _i , and each presettable counter P _i is connected to the first volume. 2 and the phase data addressed by the second volume 4.

That is, first, the clock signal (frequency ₀ ) generated by the clock generator 7 is frequency-divided by the first frequency dividing circuit 8 (1/256 in this embodiment).
The first countdown output signal is supplied to each presettable counter P _i . On the other hand, the first
The first countdown output signal from the frequency divider circuit 8 is further divided by the second frequency divider circuit 9,
The second countdown output signal is output to the ROM 1, and specifies reading of the lower address for each vibrator A _i . Furthermore, the second countdown output signal is supplied to the decoder 10. Note that the first countdown output signal and the second countdown output signal are synchronized by a timing circuit 11. The decoder 10 operates during the preset times shown in FIG. 2c and c'(c' is an enlarged view of c).
Then, a load signal L _i (i=1 to n) is sequentially output to each presettable counter P _i after being shifted by a predetermined time.
This load signal L _i is applied to the first volume 2 and the second volume 2.
ROM 1 addressed by volume 4 of
The phase data commanded by this load signal is read out at a predetermined timing and is sequentially preset in each presettable counter _{P i .} be done. For example, one of the clock signals
When the period T=1/f ₀ is divided into 256 (2 ⁸ ), if the phase displacement is 90°, a value of 256×90/360=64 is preset as phase data.

After the phase data corresponding to all presettable counters P _i has been preset in this way,
Transmitted pulses (Figure 2 a and a'), but the same figure
a' is an enlarged version of a in the figure. ) is emitted. Simultaneously with the start of this transmission pulse, each presettable counter P _i starts counting up with each phase data, that is, the preset value, as the initial value (in the above example, counting starts from the initial value 64. Note that one cycle (The count value is 256.) This count-up is performed continuously during the output period of the transmission pulse, and due to this count-up, a count-up signal C _upi (i = 1 to n) is output from each presettable counter P _i. be done. Each count-up signal C _upi is transmitted by the transmitting amplifier PA _i (i
=1 to n) into a sine waveform and is supplied to the corresponding vibrator A _i as an excitation signal. Each vibrator
A _i is excited by this excitation signal, making it possible to oscillate a beam with a set width in a set direction.

(Effects of the Invention) As explained above, the present invention includes a storage means for storing phase data as a means for phase control necessary for selecting and setting the pointing direction and pointing width;
A presettable counter is used to give a phase shift to the excitation signal, and both of these
Since it can be configured with an IC, it is highly reliable, has a simple and small-scale configuration, and can direct a directional beam in a desired direction and easily change the beam width. Therefore, when detecting a school of fast-moving fish, you can widen the beam width to avoid missing a school of fish, and when you want to clearly see the distribution of a school of fish, you can narrow the beam width to increase resolution. It has the advantage of being easy to do.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention.
Figure 2 is a signal time chart, Figure 3 is an illustration of beam pointing direction control, Figure 4 is an illustration of beam pointing width control, and Figure 5 is simultaneous control of beam pointing direction and pointing width. FIG. 6 is an explanatory diagram of the operation of the presettable counter. 1... ROM, 2... First volume (direction direction switching setting section), 4... Second volume (pointing width switching setting section), A _i , A _Li , A _Ri ... Vibrator, P _i ...Presettable counter.

Claims (1)

[Scope of utility model registration request] Directional direction command means for variably setting the beam pointing direction in the excitation signal for each of the plurality of arrayed transducers; In a beam forming apparatus provided with a pointing width commanding means for performing a phase command; the pointing direction commanding means and the pointing width commanding means store initial phase data of an excitation signal corresponding to each specified direction and each pointing width. a storage means for storing the initial phase data for each vibrator of the excitation signal corresponding to the pointing direction and pointing width set by the switching setting section; A multi-digit binary counter that is preset to a counted state by the count value corresponding to the initial phase data and starts counting from the preset value, and the most significant digit is a logic 1 and a logic 0. A beam forming device comprising: a plurality of presettable counters that output corresponding rectangular wave signals to transmission amplifiers for each transducer.