JPH041873B2 - - Google Patents

Description

[Detailed description of the invention] The present invention emits sound waves into water and detects the object by receiving a reflected signal from an object, or amplifies the received sound waves and radiates them into the water, or uses predetermined information. This invention relates to a sonar device that emits modulated sound waves underwater.

Conventionally, the transmitting acoustic power of this type of sonar device is to radiate sound waves into the water with a fixed transmitting power to a permissible acoustic power limit in order to increase the detection or receiving distance. The permissible acoustic power limit is just before cavitation occurs. However, the acoustic power per unit area generated by this cavitation increases as the water pressure applied to the transmitter increases. Therefore, if the transmission output is fixed, instead of transmitting at the maximum acoustic power (acoustic power permissible limit) at that water pressure, it is only possible to transmit at the acoustic power permissible limit at the lowest predicted water pressure. Furthermore, even if it were possible to change the transmission output, it was necessary to manually set the transmission output each time the water pressure applied to the transducer changed. In addition, when the depth at which a transducer is used constantly changes (for example, a transducer on a submersible), it is difficult to manually set the transmission output, so cavitation is caused by the water pressure at the lowest depth at which the transducer is used. The transmission output was set so that it would not occur. Therefore, it had the disadvantage that it was not possible to increase the detection distance or extend the communication distance even if the transmitter was located deep.

An object of the present invention is to provide a sonar device that can extend the detection distance and communication distance even if the depth of the transmitter increases.

The sonar device of the present invention includes a transmitter that generates an electric signal whose frequency is in a sonic or ultrasonic band and controls the power of the electric signal according to a power control signal, and converts the electric signal into a sonic or ultrasonic wave. A transmitter that emits water into the water, a water pressure detector that detects the water pressure that this transmitter receives, and a maximum electric power that is within the permissible acoustic power limit that does not cause cavitation depending on the water pressure detected by this water pressure sensor. This configuration includes a circuit that generates the power control signal.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram of a first embodiment of the present invention;
FIG. 2 is a waveform diagram of each part of the signal. This embodiment consists of a transmitter 1, a transducer 2, and a detection circuit 3. The transmitter 1 includes a pulse generation circuit 11, a variable amplification circuit 12, and a power amplification circuit 13, and the detection circuit 3 includes an amplification factor setting circuit 31 and a pressure sensor 3.
2 and 2 respectively.

The pulse generation circuit 11 generates a pulse modulated wave 111 having a predetermined frequency and a predetermined pulse width at regular intervals. A pulse modulated wave 111 generated by the pulse generation circuit 11 is amplified by a variable amplification circuit 12 at a predetermined amplification factor. The amplification factor of this variable amplifier circuit 12 is set by the detection circuit 3. Output 30 of detection circuit 3
1 is a voltage predetermined in the amplification factor setting circuit 31 in accordance with the water pressure information 302 from the pressure sensor 32. The amplification factor setting circuit 31 has a transmission output 11
In accordance with the water pressure information 302, the output voltage 301 is controlled to a value where 3 is the maximum voltage that does not cause cavitation in the transducer 2. Pressure sensor 3
Reference numeral 2 denotes a Bourdon tube that is placed in a position underwater where it receives the same pressure as the transducer 2 and senses the pressure applied to the transducer 2. Variable amplifier circuit 1
The pulse modulated wave 112 from 2 is transmitted to the power amplifier circuit 1
3, the power is amplified by the transmitter 1 and sent to the transducer 2 as a transmission output 113, and the transducer 2 radiates it into the water as a sound wave.

In this way, in this embodiment, the pressure applied to the transducer 2 is sensed by the pressure sensor 32, and the amplification factor setting circuit 31 changes the amplification factor of the variable amplification circuit 12, so that the acoustic power can be transmitted within the permissible limit. It's like this.

Next, as a second embodiment of the present invention, a method shown in a block diagram in FIG. 3 will be described. FIG. 4 is a waveform diagram of various signals in this embodiment. FIG. 3 differs from FIG. 1 only in the transmitter, and everything else is the same. The transmitter 4 includes a rectangular pulse generation circuit 1
4, a switching power amplification width circuit 15, and a variable power supply circuit 16.

A rectangular pulse generation circuit 14 generates a rectangular pulse modulated wave 4 having a predetermined frequency and a predetermined pulse width at regular intervals.
Generates 01. A rectangular pulse modulated wave 401 generated by the rectangular pulse generation circuit 14 is power amplified by the switching power amplification circuit 15. The amplifier circuit 15 that performs the switching operation can change the amplification factor by changing the power supply voltage 403. The power supply voltage 403 of the switching power amplifier circuit 15 is supplied from the variable power supply circuit 16. This variable power supply circuit 1
The power supply voltage 403 where 6 occurs is the amplification factor setting circuit 31
This is the value specified by the output voltage 301 of. Therefore, the variable power supply circuit 16 generates a power supply voltage 403 according to the water pressure information 302, and the switching power amplification circuit 15 amplifies the power of the rectangular pulse modulated wave 401 with an amplification factor according to the power supply voltage 403, and outputs a transmission output 4.
The transmitter 1 outputs the signal as 02. Transmission output 402 from the transmitter 1 is sent to the transducer 2 and radiated into the water as a sound wave.

Next, a usage example of the embodiment shown in FIG. 1 or 3 will be explained.

FIG. 5 is a schematic diagram showing a usage example in which these embodiments are mounted on a diving research vessel. This usage example is a system in which a receiving device 101 receives a sound wave signal from a sounding device 103 (pinger, underwater communication device, etc.) mounted on a research diving vessel 102 of a ship 100. When the diving depth of the underwater research vessel 102 becomes deeper, the distance between the vessel 100 and the underwater research vessel 102 becomes longer, so if the sound level of the sound generating device 103 is always constant, the reception level of the receiving device 101 decreases. However, in this usage example, the sounding device 1
Since the embodiment shown in FIG. 1 or 3 is adopted in 03, it is possible to prevent the reception level of the receiving device 101 from decreasing even if the diving depth of the research submarine 102 becomes deeper.

A second usage example is schematically shown in FIG. In this usage example, the receiving device 101 of the ship 100 is connected to a transponder 104 installed on the seabed or a dropped pinger 1.
This is a system that receives signals from 05.
The embodiment shown in FIG. 1 or 3 is adopted as the submarine-installed transponder 104 and the drop-type pinger 105.
The sound level of the dropped pinger 105 increases or decreases depending on the depth. Therefore, the transponder 104
Even if the depth of the pinger 105 increases, reception can be performed without reducing the reception level of the receiving device 101.

As explained above, the sonar device of the present invention detects the water pressure applied to the transmitter, and automatically adjusts the transmission power according to the detected water pressure to the maximum permissible acoustic power limit that does not cause cavitation. By controlling the depth of the transmitter, the transmission power can be increased as the depth of the transmitter increases, so even if the depth of the transmitter increases, the detection distance and communication distance can be extended, and the receiving device side Fluctuations in reception level can be reduced.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a first embodiment of the present invention;
FIG. 2 is a waveform diagram of each part of the signal, FIG. 3 is a block diagram of the second embodiment of the present invention, and FIG. 4 is a diagram of the second embodiment of the present invention.
FIGS. 5 and 6 are schematic diagrams illustrating usage examples of these embodiments. 1, 4... Transmitter, 2... Transmitter/receiver, 3... Detection circuit, 11... Pulse generation circuit, 12... Variable amplifier circuit, 13... Power amplifier circuit, 14... Rectangular pulse generation circuit, 15...Switching power amplifier circuit, 16...Variable power supply circuit, 31...Amplification factor setting circuit, 32...Pressure sensor.

Claims (1)

[Claims] 1. A transmitter that generates an electric signal whose frequency is in the sonic or ultrasonic band and controls the power of the electric signal according to a power control signal, and converts the electric signal into a sonic or ultrasonic wave and radiates it into the water. A wave transmitter, a water pressure detector that detects the water pressure that the wave transmitter receives,
and a circuit for generating the power control signal so that the power reaches the maximum power within the permissible acoustic power limit at which cavitation does not occur in accordance with the water pressure detected by the water pressure detector.