KR19980037297A - Pre-arranged towed sound detector using differential amplifier band filter and differential amplifier signal amplifier - Google Patents

Abstract

The present invention relates to an acoustic sensor unit of a pre-arranged tow-type sound detector, and more particularly, to an acoustic sensor unit configured to multiplex signals of a plurality of acoustic modules using a differential mux and then transmit them to the main mux. The present invention relates to a circuit method of an acoustic sensor unit configured using a bandpass filter of a differential amplifier method and a signal amplifier of a differential amplifier method such that noise cancellation and signal-to-noise ratio are good.

The present invention provides a vibration isolating module and tail rope assembly for attenuating vibration generated around an acoustic sensor unit to prevent false signals, etc .: A sound module for converting sound generated from an underwater sound source into an electrical signal: and A signal transmission module having a main mux part for converting an analog signal from the sound module into a digital signal and multiplexing and transmitting the same; A towing cable for connecting the acoustic sensor unit with the ship; And a signal processing unit for processing the acoustic signal from the acoustic sensor unit, and a data processing unit for classifying, retrieving, and processing the electrical signal data from the signal processing unit. A pre-arranged towed underwater sonar system comprising a ship connected with a common mode filter, comprising: a common mode filter connected to a rear end of each sound module to remove high-frequency noise included in an acoustic signal from the sound module; ; A normal mode filter connected to a rear end of a common mode filter to improve a signal-to-noise ratio of the acoustic signal; By providing an acoustic sensor unit characterized by using an operational amplifier for differential amplification as each of the above filters, there is an effect of providing an acoustic detector with good noise removal and good signal-to-noise ratio characteristics.

Description

Pre-arranged towed sound detector using differential amplifier band filter and differential amplifier signal amplifier

The present invention relates to an acoustic sensor unit of a pre-arranged tow-type sound detector, and more particularly, to an acoustic sensor unit configured to multiplex signals of a plurality of acoustic modules using a differential mux and then transmit them to the main mux. The present invention relates to a circuit method of an acoustic sensor unit configured using a bandpass filter of a differential amplifier method and a signal amplifier of a differential amplifier method such that noise cancellation and signal-to-noise ratio are good.

In general, in the sound detector for detecting an acoustic signal in the water to detect the exact position of the sound source, the method of detecting the sound wave in the water is an active sonar that emits sound energy and receives the reflected sound energy from the object. There is a (Sonar) method and a passive sonar method that receives only acoustic energy radiated from other sound sources.

1 is a block circuit diagram schematically showing a general sound detector, which is a sound sensor for detecting an underwater sound signal, converting it into a conventional analog signal, converting it into a digital signal, and then multiplexing and transmitting the same. Section 300; A towing cable 200 for connecting the acoustic sensor unit 300 to the ship; It is configured to include a ship 100 is connected to the acoustic sensor unit 300 by the towing cable 200.

In addition, the ship 100 is a signal processor 120 for transmitting the electrical signal received from the acoustic sensor unit 300, and a data processor 110 for classifying, searching, and processing the electrical signal data received from the signal processor 120. On the other hand, it is responsible for the function to control the sound sensor unit 300.

In addition, the acoustic sensor unit 300 is a vibration isolation module (310) for attenuating vibration generated around the acoustic sensor unit 300 to prevent false signals, and the like, and the input analog signal as a digital signal. A signal transmission module 320 for converting and transmitting, a sound module 330 for detecting the sound signal, and a tail rope assembly 340 for finally damping the vibration.

In addition, an acoustic module 330 constituting the acoustic sensor unit 300 is a module that receives sea sound signals and converts them into electrical signals to remove seawater noise flowing through the signals as shown in FIG. 2. As described above, the hydrophone (Hydrophone: 331) for receiving the acoustic signal from the seabed and converting it into an electrical signal, the preamplifier (Pre-Amp: 332) for amplifying the fine signal, and the preamplifier (332) from overcurrent are protected. Compensation circuit (Input Protector: 333), the roll sensor (335, 335a) to detect the inclination of the acoustic sensor unit 300, Sea noise correction circuit (Sea Noise Correction Amp: 334, the depth sensor 337 for measuring the depth of the acoustic sensor unit 300, the orientation sensor 338 for measuring the orientation of the acoustic sensor unit 300, and the abnormality of the acoustic sensor unit 300 is tested. The test controller 336 is configured to include.

Referring to the operation of the acoustic sensor unit 300 of the above-described configuration in detail as follows.

Underwater acoustics are propagated by the mechanical coarse action of the seawater particles, and the vibration causes a volume change in the hydrophone 331 to a magnitude proportional to the product of the square of the frequency and amplitude, and the hydrophone 331 is the volume. In response to the change, it generates an electrical signal corresponding to the electrical waveform associated with the sound wave.

The change in the electrical signal may be expressed as a change in current or voltage. In order to transmit such a change in the electrical signal over a long distance with maximum efficiency, it is necessary to match the impedance of the output terminal of the hydrophone 331 and the impedance of the preamplifier 332, and thus the electrical of the hydrophone 331 The signal can be sent far away.

The electrical signal processed as described above passes through the seawater noise compensation circuit 334. The circuit blocks noise signals in seawater existing in the low frequency region, compensates for attenuation of high frequency component signals, and transmits them to the signal transmission module 320.

In addition, the depth sensor 337 and the azimuth sensor 338 installed in the acoustic module 330 measure azimuth and depth information, which are examples of the acoustic sensor unit 300, and transmit the measured azimuth and depth information to the signal transmission module 320.

The signal transmitted to the signal transmission module 320 through the above process is sequentially multiplexed and then digitally converted through sampling and quantization to be transmitted to the ship 100 through the vibration isolation module 310.

The preamplifier 332 constituting the acoustic sensor unit 300 of the sound detector having the above function amplifies the weak signal of the output terminal of the hydrophone 331, and compensates for the attenuation of the sound wave underwater. After the treatment, the small signal of the hydrophone 331 is amplified to facilitate signal processing.

When the signal is amplified in the preamplifier 332, the minute noise flowing from the hydrophone 331 is also amplified in the signal. In addition to the ambient noise, there are also noises caused by the noise factor of the amplifier itself. Therefore, for the purpose of reducing the noise level, the amplifier circuit bandwidth of the preamplifier 332 is limited to have a predetermined value, thereby reducing the various noise levels.

FIG. 3 is a block circuit diagram of a sound detector showing an example of a prior art sound detector having a mux portion, and schematically shows a detailed configuration of the sound module and a signal transmission module having a mux portion.

The preamplifier 332 constituting the main part of the acoustic module 330 is connected to the low noise amplifier 332a for amplifying the low noise signal applied from the hydrophone 331 and the low noise amplifier 332a. A sea noise compensation amplifier 332b for blocking sea noise and compensating and outputting only a high frequency signal; a low pass filter 332c connected to the sea noise compensation amplifier 332b and passing only a low frequency portion of the applied signal; It is connected to the low pass filter 332c and consists of a current driver 332d for outputting the applied signal in the form of current in order to prevent the signal attenuation generated during long-distance transmission.

In addition, the mux 322 constituting the main portion of the signal transmission module 320 for transmitting the electric sound signal from the sound module 330 to the ship 100 is connected to the current driver 332d of the sound module 330. An analog mux 322a for multiplexing the applied and connected signals, a gain controller 322b connected to the analog mux 322a for controlling the gain of the applied signal, and a gain controller 322b And an analog / digital converter 322c for converting the applied analog signal into a digital signal.

The conventional acoustic module 330 is configured to amplify the weak sound signal from the hydrophone 331 and apply it to the sea noise compensation amplifier 332b. The seawater noise compensation amplifier 332b blocks the sea noise in the low frequency region and compensates only the high frequency signal to output the low frequency filter 332c. When a signal is applied from the seawater noise compensation amplifier 332b to the low pass filter 332c, the low pass filter 332c passes only the low frequency portion to the current driver 332d in order to prevent occurrence of frequency aliasing. Done. The current driver 332d converts the acoustic signal applied in the form of voltage to the current driver 332d in order to prevent a myth attenuation occurring during long distance transmission. Output to analog mux 322a.

However, the signal sensed by the hydrophone 331 and applied to the mux 322 of the signal transmission module 320 through the preamplifier 332 as described above is not only low in output level, but also the mux in the preamplifier 332. Since the distance to 322 is up to 120 m, noises flowing from a line between various signal transmissions are input to the mux 322 as it is, and in the gain controller 322b at the rear end of the mux 322, the noise level is thus increased. Since the gain is controlled in the state, there is a problem that the processing for the original signal is not performed properly.

The present invention has been made to solve the above problems, an object of the present invention is to transmit the sound signal detected by the acoustic sensor on the ship, so as to be transmitted as accurately as possible without being affected by ambient noise. It is to provide a device that can protect the signal.

1 is a block circuit diagram schematically showing a general sound detector,

Figure 2 is a block diagram showing in detail the sound module and vibration isolation module constituting the sound detector of FIG.

3 is a block circuit diagram schematically showing an example of the configuration of a conventional preamplifier;

4 is a block circuit diagram showing an example of the overall configuration of a line array towed type acoustic detector constructed using a differential amplifier band filter and a differential amplifier signal amplifier according to the present invention;

5 is a circuit diagram of a bandpass filter of a differential amplification method according to the present invention;

6 is a circuit diagram of a signal amplifier using a differential amplifier according to the present invention.

* Description of the symbols for the main parts of the drawings *

100; Warship 110; Data processing department

120; A signal processor 200; Towing cable

300; Acoustic sensor unit 310; Vibration Isolation Module

320; Signal transmission module 330; Sound module

331; Hydrophone vibrator 332; Preamplifier

333; Compensation circuit 334; Sea noise compensation circuit

335; Roll sensor 335; Test controller

337; Depth sensor 338; Orientation sensor

340; Tail rope assembly

IC 1, IC 2; Operational amplifiers R 1, R 1 ′; resistor

C 1, C 1 ′; Capacitors R 2, R 3; Amplification Degree Adjustable Resistors

In order to achieve the above object, the present invention, a vibration isolation module and tail rope assembly for attenuating the vibration generated around the acoustic sensor unit to prevent false signals, etc .: for converting the sound generated from the sound source underwater to an electrical signal Acoustic module: and a signal transmitting module having a main mux part for converting an analog signal from the acoustic module into a digital signal and multiplexing and transmitting the same; A towing cable for connecting the acoustic sensor unit with the ship; And a signal processing unit for processing the acoustic signal from the acoustic sensor unit, and a data processing unit for classifying, retrieving, and processing the electrical signal data from the signal processing unit. A pre-arranged tug-type underwater sound wave detector including a ship connected with a common mode, comprising: a common mode filter connected to a rear end of each sound module to remove high-frequency noise included in the sound signal from the sound module; A normal mode filter connected to a rear end of the common mode filter to improve a signal-to-noise ratio of the acoustic signal; A line array towing type sonar detector having an acoustic sensor unit is used as each of the filters as an operational amplifier for differential amplification.

At this time, the cutoff frequency of the normal mode filter is preferably 1.6 kHz, and the cutoff frequency of the common mode filter is preferably configured to be 10 kHz.

In order to achieve the above object, the present invention, vibration isolation module and tail rope assembly for attenuating the vibration generated around the acoustic sensor unit to prevent false signals, etc .: converting the sound generated from the sound source in the water into electrical signals A sound module for: A sound sensor unit comprising: a signal transmission module with a main mux unit for converting the analog signal from the sound module into a digital signal and multiplexing and transmitting the same; A towing cable for connecting the acoustic sensor unit with the ship; And a signal processing unit for processing the acoustic signal from the acoustic sensor unit, and a data processing unit for classifying, retrieving, and processing the electrical signal data from the signal processing unit. In the pre-arranged tow type underwater acoustic wave detector comprising a ship connected to the signal amplifier, the signal amplifier and the automatic gain controller of the acoustic sensor unit include an in-phase signal such as an inductive crosstalk signal included in the acoustic signal from the acoustic module. In order to eliminate the problem, it is configured to use a differential amplifier operational amplifier.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 4 is a block circuit diagram illustrating an overall configuration of a line array tow type acoustic detector configured using a differential amplifier band filter and a differential amplifier signal amplifier according to an embodiment of the present invention.

The hydrophone, which detects the sound from the underwater sound source, goes through an oscillator that converts the mechanical sound signal generated from the sound source into an analog electric signal of 10Hz to 1.6kHz, and a preamplifier that amplifies the sound signal.

The hydrophone is applied to the filter unit of the present invention via the preamplifier. The filter unit is connected to the rear end of each acoustic module to remove noise of the acoustic signal from the preamplifier and to adjust a pass band of the acoustic signal.

The configuration of the filter of the present invention is shown in FIG.

The filter of the present invention is constructed using two operational amplifiers with positive inputs of + IN and -IN. On the output side of this amplifier circuit, only the difference component at both input terminals is output. Therefore, common mode noise is not output.

The values of the resistors R 1 and R 1 ′ and the capacitors C 1 and C 1 ′ connected to the first stage of the operational amplifier serve as constants for determining the bandwidth of the filter. Is determined. Since the cutoff frequency of the normal mode filter of the present invention is preferably 1.6 kHz, the cutoff frequency of the filter is determined by R and C.

The filter of the input stage is composed of a common mode filter and a normal mode filter. At this time, the common mode filter removes the high frequency noise induced in the input cable, and the normal mode filter serves to improve the S / N ratio by limiting the bandwidth.

At this time, the smaller the bandwidth of the filter is advantageous in terms of noise, but larger than the bandwidth of the detected signal in consideration of the distortion of the signal. The cutoff frequency of the filter bandwidth at this time is preferably set to 10kHz.

In addition, the signal filtered through the filter unit is applied to the sub-mux unit, which is an analog type mux. This sub mux section multiplexes the applied signal and outputs it. The sub mux multiplexes the signals from the acoustic modules of the 12 channels filtered through the filter into serial data.

In this case, the differential mux unit receives a control signal from the ship 100, is connected to the channel selection input unit for selecting the 12 channels applied.

The signal output from the differential mux unit is connected to a rear end thereof and input to a differential amplifier and an AGC AMP for converting the output of the differential mux unit into a single-ended system. 6 is a circuit diagram of a signal amplifier using a differential amplifier according to the present invention. In this case, the amplification degree of the amplifier, that is, the gain is determined by the resistors R 2 and R 3. The amplifier and AGC AMP remove the low frequency in-phase signal such as the induced crosstalk signal.

On the other hand, the AGC AMP preferably has a gain of 24dB-30dB in order to increase the S / N ratio of the acoustic signal and the noise.

The gain-controlled multiplexed signal as described above is applied to the current driver prior to the output stage. This circuit performs a function of converting the output voltage of the gain control unit into a signal in the form of a current for long-distance signal transmission to the main mux.

As can be seen from the above description, the present invention converts the mechanical acoustic signal generated from the underwater sound source detected by the hydrophone of the acoustic module constituting the sound detector to an analog electric signal of 10 Hz ~ 1.6 kHz, and this differential After multiplexing using the mux, the acoustic signal of a plurality of acoustic modules in the acoustic sensor unit transmitting the same to the main mux using a differential amplifier band filter and a differential amplifier signal amplifier By providing the sensor section, the effect of providing an acoustic detector with good characteristics of noise reduction and signal-to-noise ratio is achieved.

While the invention has been shown and described with respect to certain preferred embodiments thereof, it will be appreciated that the invention can be varied and modified without departing from the spirit or scope of the invention as set forth in the following claims. One of ordinary skill in the art will readily know.

Claims (4)

Vibration isolating module and tail rope assembly for attenuating vibration generated around the acoustic sensor unit to prevent false signals, etc .: Acoustic module for converting sound generated from the sound source underwater into an electrical signal: and from the sound module A signal transmission module having a main mux unit for converting an analog signal into a digital signal and multiplexing the same and transmitting the analog signal; A towing cable for connecting the acoustic sensor unit with the ship; And a signal processing unit for processing the acoustic signal from the acoustic sensor unit, and a data processing unit for classifying, retrieving, and processing the electrical signal data from the signal processing unit. In the pre-arranged towed sonar system comprising a ship connected to and A common mode filter connected to a rear end of each sound module to remove high frequency noise included in the sound signal from the sound module; A normal mode filter connected to a rear end of a common mode filter to improve a signal-to-noise ratio of the acoustic signal; And an operational amplifier for differential amplification as said respective filters. The acoustic sensor unit of claim 1, wherein the cutoff frequency of the normal mode filter is preferably 1.6 kHz. The acoustic sensor unit of claim 1, wherein the cut-off frequency of the common mode filter is preferably 10 kHz. Vibration isolating module and tail rope assembly for attenuating vibration generated around the acoustic sensor unit to prevent false signals, etc .: Acoustic module for converting sound generated from the sound source underwater into an electrical signal: and from the sound module A signal transmission module having a main mux unit for converting an analog signal into a digital signal and multiplexing the same and transmitting the analog signal; A towing cable for connecting the acoustic sensor unit with the ship; And a signal processing unit for processing the acoustic signal from the acoustic sensor unit, and a data processing unit for classifying, retrieving, and processing the electrical signal data from the signal processing unit. In the pre-arranged towed sonar system comprising a ship connected to and The signal amplifier of the acoustic sensor unit and the automatic gain controller use a linear amplifier of a differential amplifier to remove an in-phase signal such as an inductive crosstalk signal included in the acoustic signal from the acoustic module. Acoustic sensor section of a towed sonar.