JPS6197583A - Phased array sonar - Google Patents

Abstract

PURPOSE:To obtain an image evenly well-focused and with a high data rate for the azimuth at the medium and low levels, by enabling the division of a hardware for forming beam. CONSTITUTION:An echo signal received with a probe 4 is introduced to delay maps 61 and 62 via a first-stage samplifier block 5 and selected properly under the control with a controller 11 to be fed to delay lines 71 and 72 separately. The output signal of the delay line 71 is applied to a DSC (digital scan converter) 9 through a switch 13 and a receiving amplifier 81 while the output signal of the delay line 72 done thereto via a receiving amplifier 82. An echo data brought into the DSC9 is shown as image on a display 10 under the control with the controller 11. Then, in the azimuth at the medium and low level, the delay maps 61 and 62 and the delay lines 71 and 72 are divided and controlled to receive an echo signal at a different azimuth and a different focus to be edited into one image.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a phased array sonar, and particularly to a phased array sonar that performs electronic real-time sector scanning and steers a beam to a wide field of view in an extremely short distance area. It is intended to improve the wave data rate. Such phased array sonar is used for medical and industrial purposes.

It can be widely applied for commercial use of fresh and sea water.

(Prior art) In the conventional normal 7-Aze array sonar,
The minimum requirement for a beamforming network (so-called beamformer) is to form only one transmission/reception line, and the hardware must also have sufficient delay means to handle the desired maximum azimuth angle, i.e., LC ladder type delay-in (for delivery beamforming), variable length shift register, preset counter, ROM and address scanner combination (all for transmitting beamforming), etc. are available.

(Problem that the invention attempts to solve) However, these hardwares are used to their fullest extent only when the azimuth angle (steering angle) of the sound rays is greatly varied; When the signal is directed toward a small angle range), most of the delay lines provided to create the reception delay map are not utilized. Although it is used as a signal path, it is not directly used to form a desired delay distribution.

Furthermore, since it is possible to receive only one echo signal of one sound ray at the same time, and the method of focusing the wavefront on that sound ray (M-focus) cannot be changed, a real-time switching type reception dynamic There was a problem in that the technique of focusing or receiving multi-beam forming (also referred to as multi-beam receiving) could not be implemented.

An object of the present invention is to provide a phased array sonar that solves these problems.

(Means for Solving the Problems) The present invention achieves the above object, and is configured to selectively apply a received echo signal to a delay line and to be able to use it separately in a sector scanning phased array sonar. A delay map, a plurality of delay lines that time-delay and output echo signals given from this delay map, and echo signals at different azimuths or different focal points by using the delay map and delay lines dividedly at medium and low azimuth angles. The apparatus is characterized in that it includes a control means for receiving a signal and controlling the image to be edited into one image.

(Example) Examples of the present invention will be described in detail below using the drawings. FIG. 1 is a diagram illustrating a main part of an embodiment of a phased array sonar according to the present invention. In the figure, 1 is a trigger generator that generates a wave transmission trigger, 2 is a wave transmission delay map, 3 is a wave transmission circuit group (so-called pulser), 4 is an array probe formed by arranging a plurality of transducers, 5
1 is a group of first-stage amplifiers that receive echo signals received by the probe 4, and 6 is a delay map that can be used in sections, for example, using a cross-point switch. Note that here, a case where the image is divided into two is shown. 71 and 72 are delay lines, and since this is an example of a two-division case, two sets are shown. n
At the time of division, there are 0 sets. 8+ and 82 are receiving amplifiers such as logarithmic amplifiers that receive the delay outputs of delay lines 71 and 72, respectively. 9 is a digital scan converter (hereinafter referred to as DSC), 10 is CR
A display device includes a T-monitor, and 11 is a controller for controlling each part. 12 is a keyboard for inputting various necessary information, and 13 is a switch.

The operation in such a configuration will be explained next.

The pulser 3 consists of individual pulsers connected to each transducer (multiple transducers) of the array probe 4, and each pulser has an output trigger of a trigger generator that is appropriately time-delayed via a transmission delay map. is given. The transmission delay map 2 can be changed under the control of the controller 11, and the direction of the ultrasonic beam transmitted from the probe 4 can be swung in a fan shape (sector scanning) as shown in FIG.

The echo signal received by the probe 4 is sent to a delay map 61.6 via the first-stage amplifier group 5, which is composed of a plurality of first-stage amplifiers provided in one-to-one correspondence with each transducer.
2. Each output of the first stage amplifier group 5 is appropriately selected on the delay map 61.62 under the control of the controller 11 and sent to the delay line 71.72, respectively.

The output signal of the delay line 71 ('output signal on one output line) is sent to the switch 13 and the receiving amplifier 81.
The output signal of the delay line 72 is also applied to the DSC 9 via a receiving amplifier 82.

Note that the switch 13 switches between connecting the delay map 7I to the receiving amplifier 81 or to the delay line 72 depending on a mode to be described later.

The echo data taken into the DSC 9 is sent to the controller 11.
The image is sent to the display device 10 under the control of , and is displayed as an image.

In the present invention, the delay map 6s is set according to the mode.
, 62 to change the connection between the output of the first stage amplifier group 5 and the delay line, and the outputs A of the receiving amplifiers 8t' and 8z in the DSC 9.

Decide whether to use both B or only one. For example, as shown in Figure 2, the maximum deflection angle θ of sector scanning
+45° (or -4
5°), when scanning starts from an angle of view of 1θ1≧
In the range up to 25", the full width signal of delay map 61.62 is applied to the full length of delay lines 7 and .72 so that it can be used. Next, in the range of 1θ1 to 25°, the mode is switched. Two sections, the delay map and delay line, are made to be used independently.

For example, as shown in FIG. 2, it is assumed that the reception amplifiers 81 and 82 receive echo signals from the left and right transmission sound lines R, which have slightly different azimuths with respect to the transmission sound line C. The controller 11 performs i-control to receive signals at different azimuths. In the DSC 9, the echo signal logarithmically amplified and detected by the receiving amplifier is A/D converted and written into a prepared frame memory in a predetermined format.

FIG. 3 is a diagram showing another method according to the present invention. That is, this is an example of a two-stage dynamic focus, in which received beamforming is performed for close range as shown by the solid line and for long range as shown by the dotted line E, although the azimuth angle is the same but the focal point is different.

These are edited into a single picture within DSCQ.

In the above description, the number of divisions of the delay map and delay line is two, but the present invention is not limited to this. Furthermore, the number of divisions may be changed depending on the deflection angle. Setting information such as the range to be divided into nine divisions, whether to use the multi-beam method or the dynamic focus method, etc., is input from the keyboard 12.

The above is the case on the receiving side, but the same idea holds true on the transmitting side in principle. However, wave transmission essentially cannot send two or more types of sound waves into the sound field at the same time, and balsa and wave transmission delay map means essentially do not follow the law of superposition, so they operate in a binary manner. I can only do it. Therefore,
If dynamic focusing of transmitted waves, multi-beam formation, etc. are to be performed, extremely strict frequency division or time division techniques must be used. When using time division, there is a drawback that the data rate cannot be improved. however,
There are cases where independent AM settings in two directions are required at the same time.

This is the case when pulsed Doppler is intended to coexist with B-mode imaging. In the former, the sound rays are shifted one by one (by increasing or decreasing the number 1 sound ray), while in the latter the sound ray remains at a constant desired sound ray. If this is done with one beamformer, the sound beam numbers or scanning data must be rewritten in a completely random access state. However, when two systems of beamformers (both transmitting and receiving) are used, the B beam only increases or decreases, and the Doppler beam does not need to be rewritten unless the desired sound ray changes. Such a procedure is possible with much less time, procedural complexity, and hardware than random access.

FIG. 4 is a diagram showing the main parts of the configuration in such a case. In this figure, a delay map 62, a delay line 72 . The connection relationship from the receiving amplifier 82 to the DSC 9 is the same as that shown in FIG. Delay map 61. The delay line 71 is used for Doppler, and the delay line 71
The output is guided to the Doppler processor 21 and processed. The output of the processor 21 is monitored by two speakers 22 and passed through a frequency analyzer (FFT etc.) 23 [)
809. For example, the scanning sequences for B mode and D mode are shown in the following table.

In this case, the repetition periods of the trigger source for B and the trigger source for D do not necessarily have to be the same. However, they do need to be synchronized.

Transmission/reception process number -mode Sound ray number i
B K i+I D, 1 + +2 8 K+1i+3゛D
/ i+4 8 K+2 i+5 D I i +5 8 K+3 (effect of invention)
.

As described above, according to the present invention, hardware for beamforming can be divided and used,
For lower azimuth angles, more homogeneous, well-focused, and high data rate images can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of a phased array sonar according to the present invention, FIGS. 2 and 3 are diagrams related to sound rays for detailed explanation of the present invention, and FIG. 4 is a diagram showing another embodiment of the present invention. It is a block diagram when implementing a method. 1...Trigger generator 2...Transmission delay map 3...Pulser 4...Array probe 5...
・First stage amplifier group 6s, 6z...Delay map 71.72...Delay line 81.82...Reception amplifier 9...O2010...Display device 11...Controller 12...Keyboard 13・
··switch

Claims (1)

[Claims] In a sector-scanning phased array sonar, there is a delay map that selectively applies received echo signals to a delay line and can be used separately, and a plurality of delay maps that output echo signals given from the delay map with a time delay. control means for receiving echo signals at different azimuth angles or different focal points and editing them into one image by using the delay map and the delay line separately at middle and low azimuth angles; A phased array sonar characterized by the following.