JPS60262076A - Transmission directivity system - Google Patents

Abstract

PURPOSE:To facilitate the specifying of the bearing directivity of a video while preventing the decline in the detection capacity by changing the bearing of a transmission beam continuously while varying the phase of a transmission signal to turn a spiral directivity beam continuously in the azimuth direction. CONSTITUTION:A digital data 61 from a memory reading (ROM)51 is converted into an analog signal 62 with a D/A converter 52 while turned to a sine wave with a low-pass filter 53 and transmitted as sound wave with a transmitter/receiver 7 via a transmitter 9 and a switch 8. Data 61 read out of each ROM corresponding to the sine wave level has a design value written thereinto beforehand to cause a continuous change of a spiral directivity beam or to cause a continuous change in the electric phase value. Then, when forming a beam B-m, a transmission signal is fed to transmitter/receiver elements from E1-El and subsequently, the elements E2-El+1 are switched over to form a beam B-m+1. Thus, the detection capacity of a sonar can be upgraded.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is a sonar device that detects a target underwater and measures the distance and direction of the object by rotating a transmitted beam in the direction of the direction. It concerns the technique of the method.

(Prior Art) FIG. 6 is a functional block diagram of a transmission system of a conventional sonar device. A transmission start pulse 20 is given from the control circuit 16 to the transmission control section 15, and the transmission control section 15 controls the switching device 11 with the transmission/reception switching signal 21 to switch between transmission and reception. Transmission timing signal 22
The beam scanning signal 23 is triggered by the □ transmission scanner 14.

The transmitting scanner 14 transmits beam B shown in FIG.

A beam forming signal is transmitted from B to B, and a rotating directional beam is transmitted.In underwater sound sonar equipment, generally when detecting a long-range target, the signal is transmitted as shown in Figure 5. 2m+1 directional beam B-, ~B for sector 0-.

After transmitting the rotating directional beam of ~&, it starts receiving and measures the distance and direction of the target.

The rotating directional beam transmission method generally uses a directional beam B-
, for a certain period of time (pulse width T,), the transmission step --- rotates the direction by the field, and then transmits the next directional beam B.
-1 is similarly transmitted for a certain period of time (T,). Thereafter, the directional beam is sequentially rotated in azimuth, and 2m+1 simple communications are performed between sector angles θS up to Byo.

The distance is measured using the time t until the received target echo signal and the target distance RtiR-/ from the speed of sound C, with the transmission start point of each directional beam as a reference.

The direction can be measured by interpolating the signal level between nine adjacent receiving directional beams using nine receiving directional beams arranged in a stepped manner on the receiving side, or from the phase difference thereof.

(Problem to be Solved by the Invention) However, in the conventional device, the rotating directional beam during transmission is transmitted by rotating the directional beam by a predetermined angle in a stepwise manner. and the target direction do not necessarily match. In that case, the level of the sound waves irradiating the target object is reduced due to the directional characteristics, resulting in a worsening of the detection situation or a reduction in the detection distance.

Furthermore, since the target image is displayed in a step-like manner due to step-by-step transmission, there was a drawback that the center of the target could not be identified.

(Means for Solving the Problems) In order to solve the drawbacks caused by the stepped azimuthal rotation of the transmitting beam in the above-mentioned prior art, the present invention company continuously rotates the rotating directional beam in the azimuth direction. , it eliminates the decline in detection ability and displays continuous target images in the azimuth direction! The aim is to provide images that make it easy to identify directions.

Namely 1. Continuous among L transducer elements arranged in a circle or arc shape! Form a transmission beam by simultaneously supplying (L) K transmission signals,
In a transmission directing method in which the direction of the transmission beam is changed sequentially from K, in which the supply of transmission signals is switched element by element using a switching circuit, a phasing circuit is used during the time when the transmission signal is supplied to one element in a set. By continuously changing the phase of the transmission signal supplied to each element, the direction of the transmission beam is continuously changed, and when the transmission signal supply is switched by one element, the transmission beam after switching changes. This is a transmission directivity method in which the phase of the transmission signal is adjusted by the phasing circuit so that the beam direction changes continuously from the same direction as the beam direction immediately before switching, similarly to the beam direction before switching.

FIG. 1 is a four-dimensional diagram showing the functional configuration for carrying out the method of the present invention. E, ~Et+t are transducer elements. Now, when we are trying to form a transmission beam of IIL by supplying transmission signals to elements E1 to E1, the transmission signal to be supplied to each element E- should take the hull-hulling θ a, from each element E+. Any value obtained by converting the length XI of a perpendicular line to line A into the phase angle of a sound wave may be used. Therefore, θ・temperature is expressed by the following formula. That is, θ・turbidity−”r(1−CO8ψ,)・・・・・・・・・・
・・・・・・・・・・・・(1)7 However, r is the radius of the circular array of transducer elements, ψ1 is the angle between the direction of the beam IL and each element E1, and the angle between the two companies underwater It is the propagation wavelength of sound waves.

Therefore, if we now try to tilt the transmitting beam by Δθ from the transmitting beam IIL, the signal θ・凰 to be supplied to each element is θml = # (1-CO3 (ψ is 4θ...・・・
...(2). Therefore, by continuously changing θ・wetting, the transmitted beam B−, can be adjusted by ±40° with respect to the direction facing during hulling given by equation (1).
It can be changed continuously by °. Therefore, if you want to turn the transmit beam in any direction,
The beam direction of the transmitted beam B-, formed by the element Es-El, is continuously changed to a certain angle in the turning direction by continuous changes in the hulling that satisfies equation (2), and then the transmitted signal is Supply element E, ~E! +
, when the azimuth of the beam B-m+1 by this element group starts exactly from the above-mentioned fixed angle, changes continuously again, and when it reaches the predetermined azimuth, the transmission signal is supplied (Niremen) Em to EJ-4. - Switch beam B to *
By repeating Q to form -m0M,
The direction of the transmitted beam can be continuously changed in all directions or over the entire range of defined sector angles.

Number 1 in Figure 1 is a transmitter that generates a signal to be a transmission signal, and number 2 is a transmitter/receiver element).ゎゎ, □6 eh □□ Ah, 3 □ This is a switching circuit that switches the supply of transmission signals to each transducer element.

Due to one or more of the operations, the direction of the transmitted beam changes continuously, so that the target is always irradiated by the maximum center of the transmitted beam. Therefore, the intensity of the irradiated sound waves does not vary depending on the direction of the target.

Furthermore, when receiving beams 5 and 6 in Fig. 2(a) receive reflected sound from the target object 4 during reception, the received wave when the direction of the conventional transmitting beam changes in a stepwise manner. For receive beam 5, the level is as shown in (a) in Figure 2), and for receive beam 6, it is as shown in -), and the interpolated video signal that combines these is (-→) on the jOcRT display. The image was step-like as shown in (2), making it difficult to identify the direction of the target.

However, when the method of the present invention is applied, the received wave level in receive beam 5 is
The received wave level in (b), ge), and the interpolated video signal in (b) are as shown in (c), and the interpolated video □. R□
-Yo. -One. , , ゛, it becomes easier to specify the direction of the target.

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

FIG. 3 is a block diagram showing the configuration of an embodiment of the present invention.

This embodiment is a method in which the electrical phase amounts of the transmitting circuit and the phasing circuit are changed simultaneously.

ROM (Read Only Memory) 5
The digital data 61 read from 1 is sent to the DA converter 52.
Then, the signal is sent to the transducer 7 via the transmitter 9 and the switch 8, and is transmitted as a sound wave.

Here, from channel 1 (ch, 1) to channel K (ch,
K) Digital data 61 read from ROM in FJ
are read out at high speed at regular intervals in synchronization with all channels by the address signal 60 from the control circuit 55.

In the waveform diagram of the phased 5 signal of each channel, corresponding data is read out at regular intervals (Ts, Ts...) as shown in FIG. In this data, a value designed to continuously change the electrical phase amount so that the rotating directional beam changes continuously is written in advance.

The switch 8 switches the transducer element to which the transmit signal is supplied from the transmitter 9. That is, when forming beam B-, the transmission signal is supplied to the transducer elements E1 to EJ, and then the transmission signal is supplied to the transducer elements)
Switch to Ex~E7-1-s and beam B-ffi+
1 and performs similar switching sequentially.

In this embodiment, the switching device 8 not only switches the transducer elements described above but also switches transmission and reception.

(Effects of the Invention) As explained above, according to the present invention, since the transmitted beam continuously rotates in azimuth, the target is always irradiated with the maximum center of the transmitted beam, so that the target object is always irradiated with the maximum center of the transmitted beam. Compared to conventional stepped directional beam transmission, where the maximum level of the transmitted beam is not always irradiated depending on the direction of the object, the level of the reflected sound waves is always stable at the maximum level, making it possible to use sonar equipment. Detection ability can be greatly improved.

Another advantage is that continuous images of the target can be obtained on the CRT display, making it easier to identify the direction of the target.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a functional configuration for carrying out the method of the present invention, and FIG. 2 is a diagram showing the state of reception of waves from a target located in an intermediate direction in the beam direction of two adjacent receiving beams.
Fig. 3 is a diagram showing the functional configuration of the embodiment of the present invention, Fig. 4 is a waveform diagram of the phased signal of each channel read out from the R-oM, and Fig. 5 is a diagram showing the step-like configuration of the prior art. FIG. 6 is a block diagram showing the configuration of a transmission system of a conventional sonar device. DESCRIPTION OF SYMBOLS 1... Transmitter, 2... Phaser circuit, 3... Switching circuit, 4... Target, 5.6... Reception beam, 7...
Transducer/receiver, 8... Switcher, 9... Transmitter, 10
... Transmitter/receiver, 11... Switch, 12... Receiver, 13... Transmitter, 14... Transmission scanner, 15.
...Transmission control unit, 16...Control circuit, 20...Transmission start pulse, 21...Transmission/reception switching signal, 22...
Transmission timing signal, 23... Beam scanning signal, 2
4... Transmission signal, 51... ROM. 52... DA converter, 53... Low pass filter, 55... Control circuit, 60... Address signal, 61
...Digital data, 62...Analog signal, 65
... Switching signal agent Yoshihiro Yahata) Fig. 1-pn Fig. 2 One branch One side

Claims (1)

[Claims] Out of the L transducer elements arranged in a circular or arc shape, transmitting signals are simultaneously supplied to consecutive/(<L)' elements to form a transmitting wave beam, and a switching circuit In the transmission directing method in which the direction of the transmission beam is sequentially changed by switching and moving the supply of the transmission signal one element at a time, each element is Continuously changing the phase of the transmitting signal supplied to the element Continuously changing the direction of the transmitting beam from the trap, reducing the supply of the transmitting signal to 1
The phase of the transmitted signal is adjusted by the phasing circuit so that when the element is switched and moved, the transmitted wave beam after switching changes continuously from the same direction as the beam direction immediately before switching to the same direction as the beam before switching. A transmission directional method that is characterized by: