JPS6227686A - Active acoustic homing apparatus for submerged navigating body - Google Patents

Abstract

PURPOSE:To reduce the reduction of an effective search area, by correcting the direction of receiving beam corresponding to the change in a navigating course angle. CONSTITUTION:The submerged sonic wave 111 radiated into water from a transmitter- receiver 2 is reflected from a submerged target 51 to be formed into a submerged sonic wave 112 which is, in turn, converted to a receiving signal by the transmitter- receiver 2 to be inputted to a receiving beam former 3. The former 3 receives the control from a controller 42 to move the direction of receiving beam. The transmitter- receiver 2 is divided into plural blocks and a digital delay circuit is provided to the former 3 corresponding to each block and, by changing the frequency of the clock pulse of said delay circuit, the direction of the receiving beam is changed in a relatively smooth manner. The course change quantity of a submerged navigating body is calculated from a compass 43 and the frequency of the clock pulse of the digital delay circuit through the controller 42 and the receiving beam is directed to the direction opposite to the submerged navigating body corresponding to the course change quantity of said navigating body to reduce the reduction in an effective search area.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an active acoustic homing device for an underwater vehicle, and particularly to an active acoustic homing device for aligning the directions of a transmitting beam and a receiving beam according to the turning motion of an underwater vehicle. The present invention relates to an active acoustic homing device for an underwater vehicle that controls and minimizes the reduction in the effective search area for detecting underwater targets.

(Prior Art) Conventionally, in an acoustic homing device mounted on an underwater vehicle, the directions of the transmitting beam and the receiving beam are the same as the course of the underwater vehicle, and in order to search for a target, the underwater vehicle It is common to perform a turning motion.

Therefore, when the underwater vehicle moves straight, the transmitting beam and the receiving beam almost match 7, so the effective search area does not decrease, but when the underwater vehicle turns, sound waves are emitted within the transmitting beam. Since the underwater vehicle has been turning since then, the direction of the receiving beam deviates from the direction of the transmitting beam, reducing the effective search area.

For example, referring to FIG. 2(a), the position tT of the underwater vehicle is
1, the transmitting beam DAI is directed in the direction N1 in front of the underwater vehicle tTx, but the receiving beam D
Since A2 changes its direction from direction Nl to direction N2 due to the turning movement of the underwater vehicle between position Tl and T2, the effective search area is only the shaded area in Figure 2 (a), which is significantly reduced. .

Countermeasures to prevent this decrease include widening the directivity width of the receive beam or providing multiple receive beams with different directions, but the former has drawbacks such as increased noise and the latter makes the device complex. There was.

(Problems to be Solved by the Invention) As described above, the problems in the conventional technology to be solved by the present invention are that when an underwater vehicle equipped with an active acoustic homing device turns, the transmission beam and the reception beam This means that the effective search area becomes narrower, making it difficult to capture underwater targets.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an active acoustic homing device for an underwater vehicle that corrects the direction of the receiving beam by the change in the azimuth angle to minimize the reduction in the effective search area. It's about doing.

Means for Solving Problem C) The active acoustic homing device for an underwater vehicle of the present invention is mounted on an underwater vehicle, emits sound waves into the water, and searches for an underwater target while searching for the underwater target. In an active acoustic homing device for an underwater vehicle that outputs information for guiding and tracking the underwater vehicle in the direction of the underwater target by detecting reflected sound waves of the underwater vehicle, each time a sound wave is emitted according to the turning movement of the underwater vehicle. (Embodiment) Next, the present invention will be described in detail with reference to the drawings showing embodiments of the present invention. Fig. 1 is a block diagram showing an embodiment of the present invention, and Figs. 2 (a) and (b) are explanations showing the relationship between the transmitting directional beam and the receiving directional beam when the underwater vehicle turns. FIG. 3 is a chart showing changes over time in the amount of course change of an underwater vehicle.

An overview of embodiments of the present invention will be described.

Referring to FIG. 2(b), the underwater vehicle is located at the position T1.
The receiving stage is between the transmitting position T1 and T2, and the turning direction T3 of the underwater vehicle is the turning direction of the underwater vehicle. In particular, underwater vehicles cannot change their course in a short period of time, so they always turn on a certain arc.

This requires special treatment of the transmit and receive beams.

At position ij T t, the underwater vehicle radiates a sound wave like a transmission beam DBI toward Nl in front of the underwater vehicle. Next, when the underwater vehicle turns from the position t'1 to T2, the received beam DA2 changes from the direction N1 to N2 as shown in FIG. 2(a), so the position of the underwater vehicle fffTx
The area where the transmitting beam DA1 and the receiving beam DA2 overlap (hatched area), that is, the effective search area is reduced. but.

As shown in Figure 2(b), the positions T1 and T2 of the underwater vehicle
Then, the traveling direction of the underwater vehicle changes by the angle θ, so
If the direction of the receiving beam DB2 is returned by an angle θ to the direction opposite to the direction of the underwater vehicle's course with respect to the front N2 of the underwater vehicle as a reference, (the result will differ depending on the distance between MTl and T2) ) The transmitting beam DBI and the receiving beam DB2 mostly overlap, so that reduction in the effective search area can be reduced.

When the next transmission is started, the direction of the receiving beam is made to match the direction of the transmitting beam, and the above steps are repeated.

Referring to FIG. 3, the horizontal axis represents time and the vertical axis represents the amount of course change of the underwater vehicle. The sending time and receiving time are also displayed. The amount of course deviation of an underwater vehicle is approximately proportional to the time based on the transmission time (there are cases where it is not proportional), and the direction of the receiving beam can be corrected in the opposite direction according to this amount of course change. When the transmission is performed, the direction of the receive beam is adjusted to the direction of the transmit beam,
Using this as a reference, the direction of the receiving beam is corrected in the opposite direction according to course change 1. Continue this for each transmission.

As described above, if the reception beam is directed in the opposite direction to the amount of course deviation of the vehicle, the reduction in the effective search area can be reduced. This method mainly searches the outside of the turning vehicle. In order to search inside the turning area of an underwater vehicle, the transmitting beam is first sent towards the inside of the turning area, the receiving beam is directed towards the transmitting beam at the time of transmission, and after that, the underwater vehicle is By pointing in the opposite direction depending on the amount of the body's course, the reduction in the effective search area can be reduced.

Here, the configuration and operation of an embodiment of the present invention will be explained.

Referring to FIG. 1, this embodiment includes a transmitting means 1, a transducer 2, a receiving beamformer 3, and a receiving control means 4.

Referring to FIG. 1, the transmitting means 1 includes a transmitting beamformer 11 and a transmitter 12. As shown in FIG. When a transmission trigger is applied to the transmitter 12 from the controller 42, a transmission output signal from the transmitter 12 is transmitted to the transducer 2 through the transmission beamformer 11.
is input. The connection of the transducer 2, which is divided into a plurality of blocks and each has a tapped phase shift circuit or a delay line added thereto, is switched by the transmitting beamformer 11 according to instructions from a controller 42 according to usage conditions. . If the transmission beam is fixed in the direction of travel of the underwater vehicle, the transmission beam former 11 is a fixed connection.

The transmission output signal input to the transducer 2 is an underwater sound wave 111
is converted into a sound wave 112 that is radiated into the water, reflected by the underwater target 51, and returns to the transducer 2 again. The underwater sound wave 112 reflected by the underwater target 51 is sent to the transducer 2
The received signal is converted into a received signal and input to the receiving beamformer 3.

The receiving beam former 3 moves the direction of the receiving beam under control from the controller 42.

In the case of reception, the transducer 2 is divided into a plurality of blocks, and the reception beamformer 3 for each block is equipped with a digital delay circuit, etc., and by changing the frequency of the clock pulse, the reception beam can be formed relatively smoothly. changing direction. Further, the amount of course deviation of the underwater vehicle is determined from the compass 43, and the frequency of the clock pulse of the digital delay circuit is controlled through the controller 42, so that the receiving beam is directed in the opposite direction in accordance with the amount of course change of the underwater vehicle. This reduces the reduction in effective search area.

A target signal is detected by a target signal detector 41 from the output of the reception beamformer 3, and the direction to the target and the distance to the target are outputted as a guidance information signal 100.

In addition, although the compass 43 is used to determine the amount of course deviation of the underwater vehicle, a rate gyro or a simpler angular accelerometer may be used instead.

(Effect of the invention) When an underwater vehicle equipped with an active acoustic homing device searches for a single underwater target while turning, the direction of the received beam is determined from the time of transmission according to the amount of course change of the underwater vehicle. Since the transmitting beam and the receiving beam can be rotated to maintain the overlap between the transmitting beam and the receiving beam, there is an effect that the reduction in the effective search area for active acoustic homing yellowing can be minimized.

4. Drawing 1vi! Figure 1 is a block diagram showing the configuration of an embodiment of the present invention, and Figures 2 (a) and (b) are transmission directional beams and reception directional beams when the underwater vehicle turns. FIG. 3 is a chart showing changes over time in the amount of course change of an underwater vehicle.

DESCRIPTION OF SYMBOLS 1...Transmission means, 2...Transmitter/receiver, emitter...Reception beam former, 4...Reception control means.

Agent Patent Attorney Susumu Uchihara □O/:i(f
Hyakura / θθ: 5 Mine 1fJ At

Claims (1)

[Claims] Mounted on an underwater vehicle, it emits sound waves into the water, searches for an underwater target, detects reflected sound waves from the underwater target, and guides the underwater vehicle in the direction of the underwater target. In an active acoustic homing device for an underwater vehicle that outputs tracking information, a receiving beam forming device controls the direction of a receiving beam to match the direction of a transmitting beam each time a sound wave is emitted according to the turning motion of the underwater vehicle. An active acoustic homing device for an underwater vehicle, comprising: