KR101821608B1 - Encoding /Decoding System for Processing Lossless Acoustic Sensor Signal and Method thereof - Google Patents

Abstract

The present invention relates to a system and a method for losslessly encoding/decoding an acoustic sensor signal. The system for losslessly encoding/decoding an acoustic sensor signal comprises: an encoding device which performs fault detection on an array sensor signal inputted from a sensor array to separate a normal channel signal and a fault channel signal, losslessly encodes the normal channel signal, and does not encode the fault channel signal or losslessly encodes the fault channel signal after preprocessing depending on a preset transmission mode; and a decoding device which analyzes encoded frame information generated by the encoding device to be classified into at least one among a fault channel encoded bit stream, a normal channel encoded bit stream, a short-time average, transmission mode information, and sensor state information, decode the normal channel encoded bit stream, and uses the short-time average after decoding the fault channel encoded bit stream to perform postprocessing.

Description

TECHNICAL FIELD [0001] The present invention relates to a system and a method for lossless encoding / decoding processing of a sound sensor signal,

The present invention relates to a system and method for lossless encoding / decoding of an acoustic sensor signal, and more particularly, to a system and method for determining the presence or absence of a failure of an acoustic sensor and lossless encoding / decoding of the sensor signal according to the determination result .

Sonar (sound navigation and ranging) is a radar equipment that uses sound waves to detect water or underwater targets. The sonar is generated so that sound waves are generated and radiated into water, and reflected waves reflected from an object in the water are received and analyzed to be able to detect water and underwater targets.

On the other hand, in transmitting / receiving or storing sensor signals obtained in an array type sonar system composed of dozens of acoustic sensors, difficulties may arise in terms of data amount. Therefore, a coding (signal compression) technique is needed to reduce the amount of data of the sensor signal.

In addition, in operating an array type sonar system composed of dozens of acoustic sensors, a failure may occur in the acoustic sensor due to physical or electrical shock to the sensor. The sensor signal in which such a failure or defect occurs causes a deterioration in the detection performance of the backlight or the system in which the possibility of false detection is increased due to the influx of noise due to the sensor defect.

Prior Art 1: Korean Laid-Open Patent Application No. 2006-0014903 (Title of the invention: Fault-type determination system and method thereof)

SUMMARY OF THE INVENTION It is an object of the present invention to provide a system and method for a lossless signal encoding / decoding processing of a sound sensor signal which causes a sensor signal to be encoded without information loss in a sonar system in which a weak target signal must be detected.

Another object of the present invention is to provide a system and method for lossless encoding / decoding processing of an acoustic sensor signal which can determine whether a failure of an acoustic sensor has occurred, and which does not encode a sensor signal determined as a failure, .

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

According to an aspect of the present invention, there is provided a sensor system including a sensor channel failure detector for detecting a failure of an array sensor signal input from a sensor array to generate sensor status information, A demultiplexer for demultiplexing the array sensor signal into a normal channel signal and a faulty channel signal, a first encoder for losslessly encoding the normal channel signal separated from the demultiplexer, and a demultiplexer for demultiplexing the demultiplexed channel signal, A normal channel coded bit stream coded by the first coder, a fault channel coded bit stream generated by a fault channel signal processor, a short-time average, a transmission error signal, Mode information to generate encoded frame information A coding device for lossless coding of a sound sensor signal including a multiplexer for generating a sound signal is provided.

The sensor channel failure detector includes an operation mode determination unit for determining a currently set operation mode, and a controller for calculating an effective value for each sensor signal when the operation mode is the high power mode, and calculating an effective value of each sensor signal based on the effective value of each sensor signal Calculates a cross rate, calculates a first parameter which is a failure judgment scale for each channel by using the effective cross rate, compares the first parameter with a predefined threshold, and judges whether the acoustic sensor related to each channel is faulty Calculating a zero crossing rate for each sensor signal when the high power mode failure detector is in a low power mode and calculating a second parameter which is a failure judgment scale for each channel using the zero crossing rate of each sensor signal, A low-power mode fault detector that compares parameters to predefined thresholds to determine if the acoustic sensors associated with each channel are faulty. Can.

Wherein the failure channel signal processor comprises: a transmission mode determination unit for determining whether a currently set transmission mode is an on state or an off state; a failure detection unit for performing a pre-processing on the failure channel signal when the transmission mode is on A channel signal preprocessor, and a second encoder for losslessly encoding the preprocessed fault channel signal and transmitting the preprocessed fault channel signal to the multiplexer. The transmission mode determiner may transmit the transmission mode information to the multiplexer when the transmission mode is off .

The fault channel signal preprocessor includes a calculator for calculating a short-time average of the fault channel signal, a quantizer for scalar quantization and dequantization of the short-time average to convert the short channel into an integer value, and a pre-processing signal generator for generating a pre-processed signal by subtracting -time average from the fault channel signal.

According to another aspect of the present invention, there is provided a decoding apparatus for decoding encoded frame information and demultiplexing the encoded frame information into at least one of a fault channel coding bit stream, a normal channel coding bit stream, a short-time average, transmission mode information, A first decoder for losslessly decoding the stream and outputting a normal channel signal, a second decoder for lossless decoding the error-channel-coded bitstream to output a faulty channel signal, a second decoder for outputting a faulty channel signal output from the second decoder, A fault channel signal post-processor for performing post-processing using the short-time average, a multiplexer for reconstructing a decoded array sensor signal using the post-processed fault channel signal, the normal channel signal, the transmission mode information, Is provided.

When the transmission mode information is off, the multiplexer reconfigures the array sensor signal by setting a signal value corresponding to the failure channel signal to a value of 0, and when the transmission mode information is on, The faulty channel signal can be used to reconstruct the array sensor signal.

The first decoder or the second decoder may be an MPEG-4 ALS decoder.

The faulty channel signal post-processor may sum the short-time average to the faulty channel signal and output the short-time average.

According to another aspect of the present invention, there is provided a method for detecting failure of an array sensor signal input from a sensor array, separating the array sensor signal into a normal channel signal and a fault channel signal, performing lossless coding for a normal channel signal, A coding apparatus for coding a signal, a coding apparatus for performing no-loss coding after pre-processing or not according to a predetermined transmission mode, and a coding apparatus for analyzing coding frame information generated by the coding apparatus to generate a fault channel coding bit stream, a normal channel coding bit stream, Transmission mode information, and sensor status information, performs lossless decoding for a normal channel coded bit stream, performs post-processing using the short-time average after lossless decoding for a failed channel coded bit stream, Processed fault channel signal, normal channel signal, transmission mode information, sensor status information Utilized may include a decoding unit for reconstructing the array sensor signals.

The encoding apparatus can output only the transmission mode information without coding the fault channel signal when the transmission mode is set to the ON state and in the OFF state without coding the fault channel signal after the preprocessing.

The pre-processing may include calculating a short-time average for the failed channel signal, converting the short-time average to an integer value by scalar quantization and dequantization, and subtracting the converted short-time average from the fault channel signal It can mean something.

And the post-processing may add the short-time average to the fault channel signal.

According to the present invention, it is possible to determine whether or not a failure of an acoustic sensor has occurred, encode a sensor signal judged as a failure, perform coding after performing a preprocessing, and encode a sensor signal without information loss in a sonar system, can do.

In addition, it is possible to reduce the amount of compressed data of the sensor signal and reduce the amount of calculation required for compression through the exclusion of the fault channel through automatic fault detection of the sensor signal. As a result, it can be effectively used in a limited communication environment, equipment with a limited amount of computation and power environment.

The effects of the present invention are not limited to the above-mentioned effects, and various effects can be included within the scope of what is well known to a person skilled in the art from the following description.

1 is a diagram illustrating a system for lossless encoding / decoding processing of an acoustic sensor signal according to an embodiment of the present invention.
2 is a block diagram illustrating a configuration of an encoding apparatus according to an embodiment of the present invention.
3 is a block diagram showing the configuration of the sensor channel failure detector shown in FIG.
4 is a block diagram showing the configuration of the fault channel signal preprocessor shown in FIG.
5 is a block diagram schematically showing a configuration of a decoding apparatus according to an embodiment of the present invention.
6 is a diagram for explaining the operation of the fault channel signal post-processor shown in FIG.
FIG. 7 is a flowchart illustrating a method for lossless coding an acoustic sensor signal by an encoding apparatus according to an embodiment of the present invention.
8 is a flowchart illustrating a sensor channel failure detection method according to an embodiment of the present invention.
9 is a flowchart illustrating a method of decoding a channel signal by a decoding apparatus according to an embodiment of the present invention.

The foregoing and other objects, features, and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a system and method for a lossless signal encoding / decoding process of a sound signal according to the present invention will be described in detail with reference to the accompanying drawings. The embodiments are provided so that those skilled in the art can easily understand the technical spirit of the present invention, and thus the present invention is not limited thereto. In addition, the matters described in the attached drawings may be different from those actually implemented by the schematic drawings to easily describe the embodiments of the present invention.

In the meantime, each constituent unit described below is only an example for implementing the present invention. Thus, in other implementations of the present invention, other components may be used without departing from the spirit and scope of the present invention. In addition, each component may be implemented solely by hardware or software configuration, but may be implemented by a combination of various hardware and software configurations performing the same function. Also, two or more components may be implemented together by one hardware or software.

Also, the expression " comprising " is intended to merely denote that such elements are present as an expression of " open ", and should not be understood to exclude additional elements.

Generally, the fault sensor signal has a rms value that is larger or smaller than the other normal channel signals. Therefore, in the conventional diagnosis of the sensor defect, the effective value of the signal input to the entire sensor is measured for each sensor channel and is displayed on the operation screen. When the difference in the effective value between the sensor channel and the adjacent sensor channel is visually large, The concept of manual judgment is mainly applied.

However, when the environmental noise around the sensor array increases greatly, the effective value of the signal input to the adjacent sensor increases, and it becomes difficult to visually distinguish the difference in the effective value between the faulty channel and the normal channel. Therefore, according to the conventional method, it is difficult to distinguish a channel in which a failure occurs and a normal channel.

In addition, since the operator performs manual fault diagnosis, it is not possible to immediately respond to the fault sensor channel, and the sensor is judged as a fault sensor, so that the noise is introduced due to the fault of the sensor before the fault processing for the corresponding sensor channel is performed. False positives can continue to occur.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a sonar system which can detect a malfunction of a submersible acoustic sensor, encode sensor signals judged as malfunctions, To a technique for lossless encoding / decoding a sensor signal.

Hereinafter, the present invention will be described in detail with reference to the drawings.

1 is a diagram illustrating a system for lossless encoding / decoding processing of an acoustic sensor signal according to an embodiment of the present invention.

1, the acoustic sensor signal losslessness processing system includes an encoder 200 for losslessly encoding an array sensor signal input from an underwater acoustic sensor 100, a lossless decoding unit 220 for lossless decoding the encoded frame information generated by the encoder 200, And a decoding device (300) for restoring the sensor signal.

The underwater acoustic sensor 100 converts an electrical signal generated in the system into an acoustic signal and emits it to the outside, and converts an acoustic signal received from the outside into an electrical signal. The underwater acoustic sensor 100 may be implemented as an underwater acoustic sensor array, acoustic sensor modules, or the like.

A multiplexer that supplies power to each underwater acoustical sensor array to perform an underwater acoustic sensor array or analog-to-digital conversion breaks down and a sensor fault occurs. When a sensor defect occurs, a signal input from a specific sensor has a large difference value from signals input from adjacent sensors. The encoding device 200 detects a failure of the underwater acoustic sensor in consideration of this point.

The encoding apparatus 200 performs a failure detection on the array sensor signal input from the acoustic sensor array 100 and separates the signal into a normal channel signal and a failure channel signal. In the case of a normal channel signal, lossless coding is performed. Lossless coding is performed after pre-processing. Then, the encoding apparatus 200 generates encoded frame information including a failure channel encoded bit stream, a normal channel encoded bit stream, a short-time average, transmission mode information, and sensor status information.

That is, the encoding apparatus 200 performs a failure detection on the sensor signal, and performs normalization of the normal channel signal, which is determined to be normal, to lossless encoding using an MPEG-4 ALS (Audio Lossless Coding) . In addition, the encoding apparatus 200 does not encode the failure channel signal determined as a failure according to the transmission mode, or performs lossless encoding after performing the pre-processing. At this time, in the case of the failure channel signal transmission mode, the encoding apparatus 200 generates an MPEG-4 ALS bitstream by performing lossless coding using an MPEG-4 ALS encoder after performing pre-processing, , The failure channel signal is not encoded and only the status information of the channel is combined.

The coding apparatus 200 will be described in detail with reference to FIG.

The decoding apparatus 300 analyzes the encoded frame information generated by the encoding apparatus 200 and separates the encoded frame information into a normal channel signal and a failed channel signal. The normal channel signal is lossless decoded. The decoded channel signal is decoded and post- post-processing.

That is, the decoding apparatus 300 analyzes the header information of the encoded bit stream, and restores the sensor bit stream using the MPEG-4 ALS decoder. In addition, the decoding apparatus 300 performs lossless decoding on the coded bit stream of the channel signal determined to be defective using the MPEG-4 ALS decoder, and then performs post-processing to restore the defective channel signal do.

The decoding apparatus 300 will be described in detail with reference to FIG.

FIG. 2 is a block diagram illustrating the configuration of an encoding apparatus according to an embodiment of the present invention. FIG. 3 is a block diagram illustrating the configuration of the sensor channel failure detector shown in FIG. 2. FIG. Fig. 2 is a block diagram showing a configuration of a processor.

2, the encoding apparatus 200 includes a signal acquisition unit 210, a sensor channel failure detector 220, a demultiplexer 230, a first encoder 240, a transmission mode determination unit 250, A pre-processor 260, a second encoder 270, and a demultiplexer 280.

The signal acquisition unit 210 transmits the array sensor signals input from the sensor array to the sensor channel failure detector 220 and the demultiplexer 230.

The sensor channel failure detector 220 performs a failure detection on the array sensor signal transmitted from the signal acquisition unit 210 to determine whether the sensor channel is malfunctioning. At this time, the sensor channel failure detector 220 performs the failure detection differently according to the operation mode set in the system. Here, the operation mode may include a high power mode and a low power mode.

3, the sensor channel failure detector 220 includes an operation mode determination unit 222, a high-power mode failure detector 224, and a low-power mode failure detector 226. [

The operation mode determination unit 222 determines whether the operation mode set in the current system is a low power mode or a high power mode. Here, the low power mode can be used in the case where the equipment performing the compression is limited to the hardware operation amount such as the embedded board, the equipment using the battery for the mobile operation, and the high power mode, When the amount of computation is large, it can be applied to a case in which a constant power supply is possible by a cable or the like.

In the high power mode, the high power mode failure detector 224 operates and, in the low power mode, the low power mode failure detector 226 operates.

The high power mode failure detector 224 performs linear integration on the input sensor signal and calculates the root mean square (RMS) for each linearly integrated channel signal. Then, the high-power mode failure detector 224 calculates the Root Mean Square Crossing Rate of each channel signal based on the effective value of each channel signal, and calculates a failure determination criterion for each channel Calculate one parameter. Then, the high power mode failure detector 224 compares the first parameter of each channel with a predefined threshold to determine whether each channel is faulty.

The high power mode failure detector 224 includes an effective value calculator 224a, an effective cross rate calculator 224b, a first parameter calculator 224c and a first failure channel determiner 224d.

The rms value calculating unit 224a linearly integrates the sensor signals of the respective channels, and then calculates the rms value. That is, the effective-value calculating unit 224a performs linear integration on each sensor signal. When M channel sensor signals are inputted from the underwater acoustic sensors, the effective value calculating unit 224a can perform linear integration on the M channel sensor signals based on the predetermined integration time T. [ Then, the effective-value calculating unit 224a calculates the effective value of the sensor signal of each channel. At this time, the effective-value calculating unit 224a can calculate the effective value ri of each sensor signal of each channel by using the following equation (1).

In the above, ri denotes the effective value of the i-th sensor channel. M represents the total number of sensors included in the sensor array. N denotes a frame size, T denotes an integration time, and the unit is second. xi (n) denotes the n-th sample of the i-th sensor signal. Where i denotes the number of channels and n denotes the number of samples per channel. xi (n) can be defined by the following equation (2).

The effective cross rate calculation unit 224b calculates an RMSCR (Root Mean Square Crossing Rate) for each channel signal based on the effective value of each channel signal. At this time, the effective cross rate calculation unit 224b may calculate an effective cross rate for each channel signal using the following equation (3).

In the above, Ri denotes an effective value crossing rate for the sensor signal of the i-th channel. N denotes a frame size, and T denotes an integration time. In addition, w (x) is an intersection determination function for calculating an RMSCR value, that is, an RMSCR value, and can be obtained using the following equation (4). w (x) is 1 for the increase value and -1 for the decrease value when there is an effective value between the value of the immediately preceding sample signal and the value of the current sample signal (in the case of intersection based on the effective value) 0 is a function.

In the above, ri is the effective value (RMS) of the i-th channel signal, and v (x) is an intersection determination function for calculating the zero crossing rate, that is, the ZCR value. v (x) is 1 for the increment value and -1 for the decrease value when there is a 0 value between the value of the immediately preceding sample signal and the value of the current sample signal (when the value crosses with 0) 0 is a function. The function w (x) is extended to a function that counts the number of cross-samples of the rms value for v (x) that counts the number of samples that cross zero.

As described above, the effective cross rate calculation unit 224b can calculate the effective cross rate of the first sensor signal based on the effective value of the first sensor signal and the second sensor signal input to the first channel.

)를 각각 계산할 수 있다.The first parameter calculator 224c calculates a first parameter for determining the failure of each sensor channel on the basis of the effective cross ratio of each sensor signal. That is, the first parameter calculator 224c calculates a channel-by-channel failure determination parameter for determining whether or not the sensor is a failure sensor based on the effective cross ratio for each channel signal. At this time, the first parameter calculator 224c calculates a first parameter ((

Respectively.

는 i번째 채널 센서가 고장센서인지 여부를 판단하기 위한 파라미터를 의미한다. M은 센서 어레이(array)에 포함되는 센서들의 전체 개수를 의미한다.In the above,

Denotes a parameter for determining whether the i-th channel sensor is a failure sensor. M represents the total number of sensors included in the sensor array.

The first fault channel determination unit 224d compares the first parameter with at least one first threshold value to determine whether the acoustic sensor associated with the first channel is faulty. That is, the first failure channel determination unit 224d compares the first parameter, which is a failure determination parameter for each channel, with a predefined failure determination threshold to determine whether each sensor is faulty. At this time, the first failure channel determination unit 224d determines the i-th channel as a failure channel when the first parameter value of the i-th sensor channel is larger than the first minimum threshold value and smaller than the first maximum threshold value. The first failure channel determination unit 224d determines that the i-th channel is a failure channel when the first parameter value of the i-th sensor channel is smaller than the first minimum threshold value or greater than the first maximum threshold value.

Next, the low power mode failure detector 226 performs a linear integration on the sensor signal and calculates a zero crossing rate for each channel input signal on which the linear integration is performed. Then, the low-power mode failure detector 226 calculates a second parameter, which is a zero crossing rate-based failure determination criterion, using the zero crossing rate, compares the second parameter for determining the failure of each channel with a predetermined threshold, And judges whether or not each channel is faulty.

The low power mode failure detector 226 includes a zero crossing rate calculation unit 226a, a second parameter calculation unit 226b, and a second failure channel determination unit 226c.

The zero crossing rate calculator 226a linearly integrates the sensor signals of the respective channels, and calculates a zero crossing rate (ZCR). That is, the zero crossing rate calculator 226a linearly integrates the input sensor signal with respect to the predetermined integration time, and calculates the zero crossing rate of each channel signal subjected to the linear integration. At this time, the zero crossing rate calculator 226a can calculate the zero crossing rate Zi using Equation (6).

The second parameter calculator 226b calculates a second parameter for determining the failure of each channel on the basis of the zero crossing rate of each sensor signal. At this time, the second parameter calculator 226b may calculate the second parameter for determining the failure of each channel using Equation (7).

The second fault channel determination unit 226c compares the second parameter with a predefined second threshold to determine whether the acoustic sensor associated with each channel is faulty. That is, the second failure channel determination unit 226c compares the second parameter, which is a failure determination parameter of each channel, with the failure determination threshold value, and determines whether or not each channel is faulty. If the second parameter value of the i-th sensor channel is greater than the predefined minimum threshold value, the second failure channel determination unit 226c determines that the i-th channel is a failure channel and the second parameter value Is smaller than the minimum threshold value, the i-th channel is determined as a failure channel.

The sensor channel fault detector 220 configured as described above determines whether the sensor signal of each channel is faulty, generates sensor state information according to the determination result, and transmits the sensor state information to the demultiplexer 230 and the multiplexer 280. Here, the sensor status information may include sensor identification information, whether or not each sensor is normal (normal), and the like.

Referring again to FIG. 2, the demultiplexer 230 separates the array sensor signal into a normal channel signal and a fault channel signal using the sensor state information. That is, the demultiplexer 230 separates the sensor signal transmitted from the signal acquisition unit 210 into a normal channel signal and a failed channel signal based on the channel state information transmitted from the sensor channel failure detector 230. Since the channel status information includes the sensor channel identification information and the failure status, the demultiplexer 230 can separate each sensor signal into a normal channel signal and a failure channel signal. Then, the demultiplexer 230 transmits the normal channel signal to the first encoder 240 and transmits the failure channel signal to the transmission mode determination unit 250.

The first encoder 240 losslessly encodes the normal channel signal transmitted from the demultiplexer 230. Here, the first encoder 240 may be an MPEG-4 ALS encoder, MPEG-4 ALS-encodes a normal channel signal, and outputs an MPEG-4 ALS encoded bitstream.

The transmission mode determination unit 250 determines whether the transmission mode set in the current system is on or off and performs preprocessing of the faulty channel signal according to the determination result. That is, when the transmission mode is off with respect to the failure channel signal, the transmission mode determination unit 250 transmits the transmission mode information on the failure channel signal to the multiplexer 280. When the transmission mode is on, the transmission mode determination unit 250 determines the failure channel signal as the failure channel signal And transmits it to the preprocessor 260.

The transmission mode determination unit 250 does not code all the fault channel signals but codes the fault channel signals whose transmission mode is OFF and the transmission mode is ON after performing the preprocessing, The amount of compressed data can be reduced.

The fault channel signal preprocessor 260 performs pre-processing on the fault channel signal before lossless coding. That is, the faulty channel signal preprocessor 260 calculates an average value for the faulty channel signal, converts the calculated average value to an integer value using a 16-bit quantizer, subtracts the average value converted from the faulty channel signal to an integer value Thereby generating a preprocessed signal. In the case of a fault channel, the signal is biased to a specific value. The smaller the variance of the signal is, the better the compression efficiency becomes. Therefore, the mean value is subtracted to eliminate the deflection component of the signal value for the fault channel.

4, the fault channel signal preprocessor 260 includes an average value calculating unit 262, a quantizing unit 264, and a preprocessing signal generating unit 268.

)를 계산할 수 있다. The average value calculation unit 262 calculates a short-time average for the failed channel signal. At this time, the average value calculator 262 calculates the short-time average (

) Can be calculated.

은 고장채널신호이고, i는 고장 센서 채널 번호, m은 프레임 번호를 의미한다. N은 1개 프레임 번호에 있는 전체 샘플 수를 의미한다. 따라서, 수학식 8은 i번째 센서에 수신되는 센서신호에 대하여 m번째 프레임의 전체 샘플에 대한 평균을 계산하는 의미한다. Where M denotes the total number of fault channel signal sensors.

I is a fault sensor channel number, and m is a frame number. N means the total number of samples in one frame number. Accordingly, Equation (8) means to calculate an average of all samples of the m-th frame with respect to the sensor signal received by the i-th sensor.

The quantization unit 264 quantizes the short-time average calculated by the average value calculation unit 262 by 16 bits and converts it into an integer value. That is, the quantization unit 264 converts the value using the 16-bit scalar quantization unit Q and the non-quantization unit Q-1. At this time, the quantization unit 264 transforms the value of the short-time average using Equation (9).

The sensor signal value is a 16-bit integer quantized value, and a 16-bit integer value must be input as the input of the encoder. In the case of taking an average of the sensor signal, a floating-point value is outputted. Therefore, if the original sensor signal is subtracted from the original sensor signal, the resultant value becomes a floating-point value. To prevent this, the scalar quantization unit And converts it to a 16-bit integer value using the non-quantization unit (Q-1).

The quantization unit 264 transmits the converted short-time average to the multiplexer 280.

)를 생성한다. The preprocessing signal generator 268 subtracts the short-time average converted by the quantizer 264 from the failure channel signal to generate a preprocessed signal. That is, the preprocess signal generator 268 generates the preprocessed signal (

).

The preprocessing signal generator 268 transmits the preprocessed fault channel signal to the second encoder 270.

The second encoder 270 losslessly compresses the preprocessed fault channel signal transmitted from the faulty channel signal preprocessing unit 260. Here, the second encoder 270 may be an MPEG-4 ALS encoder, and performs MPEG-4 ALS coding on the preprocessed failure channel signal to output an MPEG-4 ALS encoded bitstream.

The transmission mode determination unit 250, the failure channel signal preprocessor 260, and the second encoder 270 may be combined to be referred to as a failure channel signal processor. The failure channel signal processor may include a failure The channel signal is subjected to pre-processing based on a predetermined transmission mode, and is losslessly encoded. The transmission mode determination unit 250, the faulty channel signal preprocessor 260, and the second encoder 270 may be included.

The multiplexer 280 multiplexes the encoded bit stream compressed by the first and second encoders 240 and 270, the short-time average generated by the failure channel signal preprocessor 260, transmission mode information on the failure channel signal, To generate encoded frame information.

FIG. 5 is a block diagram schematically showing a configuration of a decoding apparatus according to an embodiment of the present invention, and FIG. 6 is a diagram for explaining the operation of the fault channel signal post-processor shown in FIG.

5, the decoding apparatus 300 includes a demultiplexer 310, a first decoder 320, a second decoder 330, a faulty channel signal post-processor 340, and a multiplexer 350.

The demultiplexer 310 analyzes the header information of the encoded frame information and separates the encoded channel bit stream, the normal channel encoded bit stream, the short-time average, the transmission mode information, and the sensor status information. At this time, the demultiplexer 310 transmits the normal channel encoded bit stream to the first decoder 320, the fail channel encoded bit stream to the second decoder 330, and outputs the short-time average to the failed channel signal post- 340, and transmits the transmission mode information and the sensor status information to the multiplexer 350.

The first decoder 320 performs MPEG-4 ALS decoding on the normal channel coded stream demultiplexed by the demultiplexer 310 to recover the normal channel signal, and outputs the restored normal channel signal to the multiplexer 350. In this case, the first decoder may be an MPEG-4 ALS decoder.

The second decoder 330 performs MPEG-4 ALS decoding on the faulty channel-encoded stream demultiplexed by the demultiplexer 310, restores the faulty channel-signal to a faulty channel signal, and transmits the recovered faulty channel signal to the faulty channel signal processor 340 . At this time, the second decoder 330 may be an MPEG-4 ALS decoder.

The faulty channel signal post-processor 340 performs post-processing on the decoded faulty channel signal using the short-time average separated by the demultiplexer 310. That is, the faulty channel signal post-processor 340 adds the short-time average to the decoded faulty channel signal as shown in FIG. 6 to generate a post-processed faulty channel signal.

The multiplexer 350 demultiplexes the fault channel signal and the normal channel signal separated according to the presence or absence of the fault using the post-processed fault channel signal, the decoded normal channel signal, the transmission mode information, and the sensor state information, Lt; / RTI > At this time, when the transmission mode information is off, the multiplexer 350 reconfigures the array sensor signal by setting the signal value corresponding to the failure channel signal to '0' value.

The system constructed as described above can be applied to an underwater acoustic sensor-based sonar system. The present invention can also be applied to an acoustic apparatus using an acoustic microphone or the like.

FIG. 7 is a flowchart illustrating a method for lossless coding an acoustic sensor signal by an encoding apparatus according to an embodiment of the present invention.

Referring to FIG. 7, when an array sensor signal is received from a sensor array (S702), the encoding apparatus performs a failure detection on the array sensor signal (S704). At this time, the encoder performs a failure detection on each sensor signal and separates the signal into a normal channel signal and a fault channel signal. A detailed description of how the encoding apparatus performs the failure detection will be described with reference to FIG.

If it is determined in step S706 that the failure channel signal is a failure detection result, the encoding apparatus determines whether the transmission mode set in the current system is on in step S708.

 If the transmission mode is on, the encoder performs pre-processing on the failed channel signal (S712). That is, the encoding apparatus calculates an average value for a faulty channel signal, converts the calculated average value to an integer value using a 16-bit quantizer, subtracts an average value converted from the error channel signal to an integer value, and generates a preprocessed signal do.

The encoding apparatus performs MPEG-4 ALS encoding on the preprocessed failure channel signal and outputs an MPEG-4 ALS encoded bitstream (S712).

If it is determined in step S708 that the transmission mode is OFF, the encoding apparatus outputs the transmission mode information for the corresponding failure channel signal (S714).

If it is determined in step S706 that the normal channel signal is a result of the failure detection, the encoder performs an MPEG-4 ALS encoding on the normal channel signal and outputs an MPEG-4 ALS encoded bit stream in step S716.

Thereafter, the encoder generates encoded frame information by integrating the encoded bit stream, the short-time average, the transmission mode information on the failure channel signal, and the sensor status information (S718).

8 is a flowchart illustrating a sensor channel failure detection method according to an embodiment of the present invention.

Referring to FIG. 8, the encoding apparatus determines whether a transmission mode set in the current system is a high power mode (S802).

 As a result of the determination in step S802, if the mode is the high power mode, the encoding device performs linear integration on the input sensor signal (S804), and calculates an effective value for each linearly integrated channel signal (S806).

Then, the encoding apparatus calculates an effective cross rate of each channel signal based on the effective value of each channel signal (S808), and calculates a first parameter which is a failure judgment scale using the effective cross rate (S810).

Then, the encoding apparatus determines whether the first parameter value of each channel failure determination exceeds a predefined first minimum threshold value and is less than a first maximum threshold value (S812).

If it is determined in step S812 that the first parameter is greater than the first threshold value and less than the first threshold value, it is determined to be a normal sensor channel in step S814. Otherwise, the channel is determined to be a failure sensor channel in step S818.

If it is determined in step S802 that the mode is the low power mode, the encoding device performs linear integration on the input sensor signal (S718) and calculates a zero crossing rate for each channel input signal subjected to the linear integration (S820).

Then, the encoding apparatus calculates a second parameter, which is a failure judgment measure, using the zero crossing rate (S822), and determines whether the second parameter is greater than a predefined second minimum threshold value (S824).

If it is determined in step S824 that the second parameter does not exceed the second minimum threshold value, the sensor is determined to be a normal sensor (S826). If the second minimum threshold value is not exceeded, the sensor is determined to be a failure sensor (S828).

9 is a flowchart illustrating a method of decoding a channel signal by a decoding apparatus according to an embodiment of the present invention.

Referring to FIG. 9, the decoding apparatus analyzes the encoded frame information and separates it into a normal channel signal and a failed channel signal (S902).

In step S904, the decoding apparatus performs MPEG-4 ALS decoding on the faulty channel coded stream to recover the faulty channel signal in step S904, and performs post-processing on the decoded faulty channel signal using a short-time average in step S906. That is, the decoding apparatus adds the short-time average to the decoded fault channel signal to generate a post-processed fault channel signal.

The decoding apparatus decodes the normal channel coded stream into MPEG-4 ALS decoding and restores it into a normal channel signal (S908).

Thereafter, the decoding apparatus reconstructs the sensor signal using the post-processed fault channel signal, the decoded normal channel signal, the transmission mode information, and the sensor state information (S910). At this time, when the transmission mode information is off, the decoding apparatus reconstructs the sensor signal after setting the fault channel signal to '0' value, and when the transmission mode information is on, the decoding apparatus transmits the decoded fault channel signal to the sensor It is used for signal reconstruction.

Meanwhile, the method for lossless encoding / decoding processing of the acoustic sensor signal can be written in a program, and the codes and code segments constituting the program can be easily deduced by a programmer in the field. In addition, a program for a method for lossless encoding / decoding processing of a sound sensor signal is stored in an information storage medium (Readable Media) readable by an electronic device, and can be read and executed by an electronic device.

Thus, those skilled in the art will appreciate that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative only and not restrictive of the scope of the invention. It is also to be understood that the flow charts shown in the figures are merely the sequential steps illustrated in order to achieve the most desirable results in practicing the present invention and that other additional steps may be provided or some steps may be deleted .

The technical features and implementations described herein may be implemented in digital electronic circuitry, or may be implemented in computer software, firmware, or hardware, including the structures described herein, and structural equivalents thereof, . Also, implementations that implement the technical features described herein may be implemented as computer program products, that is, modules relating to computer program instructions encoded on a program storage medium of the type for execution by, or for controlling, the operation of the processing system .

In the present specification, the term " system ", "device" includes all apparatuses, apparatuses, and machines for processing data including, for example, a processor, a computer or a multiprocessor or a computer. The processing system may include any code that, in addition to the hardware, forms an execution environment for a computer program upon request, such as, for example, code that constitutes processor firmware, a protocol stack, a database management system, an operating system, can do. A computer program, known as a program, software, software application, script or code, may be written in any form of programming language, including compiled or interpreted language or a priori, procedural language, Routines, or other units suitable for use in a computer environment.

Configurations implementing the technical features of the present invention, which are included in the blocks and flowcharts shown in the drawings attached hereto, refer to the logical boundaries between the configurations. However, according to an embodiment of the software or hardware, the depicted arrangements and their functions may be implemented in the form of a stand alone software module, a monolithic software structure, a code, a service and a combination thereof and may execute stored program code, All such embodiments are to be regarded as being within the scope of the present invention since they can be stored in a medium executable on a computer having a processor and their functions can be implemented.

Accordingly, the appended drawings and the description thereof illustrate the technical features of the present invention, but should not be inferred unless a specific arrangement of software for implementing such technical features is explicitly mentioned. That is, various embodiments described above may exist, and some embodiments may be modified while retaining the same technical features as those of the present invention, and these should also be considered to be within the scope of the present invention.

It should also be understood that although the flowcharts depict the operations in the drawings in a particular order, they are shown for the sake of obtaining the most desirable results, and such operations must necessarily be performed in the specific order or sequential order shown, Should not be construed as being. In certain cases, multitasking and parallel processing may be advantageous. In addition, the separation of the various system components of the above-described embodiments should not be understood as requiring such separation in all embodiments, and the described program components and systems are generally integrated into a single software product, It can be packaged.

As such, the specification is not intended to limit the invention to the precise form disclosed. While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art without departing from the spirit and scope of the present invention as defined by the appended claims. It is possible to apply a deformation. The scope of the present invention is defined by the appended claims rather than the foregoing description, and all changes or modifications derived from the meaning and scope of the claims and equivalents thereof are deemed to be included in the scope of the present invention. .

100: underwater acoustic sensor 200: encoding device
210: signal acquisition unit 220: sensor channel failure detector
230: demultiplexer 240: first encoder
250: Transmission mode determination unit 260: Fault channel signal preprocessor
270: second encoder 280, 310: demultiplexer
300: Decryption apparatus 320: First decryptor
330: second decoder 340: fault channel signal post-processor
350: Multiplexer

Claims (12)

A sensor channel failure detector for detecting a failure of an array sensor signal input from a sensor array to generate sensor status information;
A demultiplexer for separating the array sensor signal into a normal channel signal and a fault channel signal using the sensor state information;
A fault channel signal processor for performing lossless coding on the fault channel signal separated by the demultiplexer after pre-processing based on a predetermined transmission mode; And
And at least one of the sensor status information, the normal channel encoding bit stream generated by lossless encoding the normal channel signal, the error channel encoding bit stream generated by the failure channel signal processor, the short-time average, and the transmission mode information, A multiplexer for generating frame information; And an encoder for lossless encoding the acoustic sensor signal. The method according to claim 1,
The sensor channel failure detector comprises:
An operation mode determination unit for determining a currently set operation mode;
When the operation mode is the high power mode, an effective value is calculated for each sensor signal, and an effective value cross rate of each sensor signal is calculated based on the effective value of each sensor signal. Based on the effective value cross rate, A high power mode failure detector for calculating one parameter and comparing the first parameter with a predefined threshold to determine the failure of the acoustic sensor associated with each channel; And
When the operation mode is the low power mode, the zero crossing rate is calculated for each sensor signal, and the second parameter, which is a failure judgment scale for each channel, is calculated using the zero crossing rate of each sensor signal. And a low power mode failure detector that compares the threshold value with a threshold value to determine whether the acoustic sensor associated with each channel is malfunctioning. The method according to claim 1,
The fault channel signal processor comprises:
A transmission mode determination unit for determining whether a currently set transmission mode is on or off;
A fault channel signal preprocessor for performing pre-processing on the fault channel signal when the transmission mode is on; And
And a second encoder for lossless encoding the pre-processed fault channel signal and transmitting the lossless encoded signal to the multiplexer,
Wherein the transmission mode determination unit transmits the transmission mode information to the multiplexer when the transmission mode is in an off state. The method of claim 3,
The fault channel signal preprocessor includes:
A calculating unit for calculating a short-time average with respect to the fault channel signal;
A quantizer for scalar-quantizing and dequantizing the short-time average and converting the short-time average into an integer value; And
And a preprocessing signal generator for generating a preprocessed signal by subtracting the short-time average converted by the quantization unit from the failure channel signal. A demultiplexer for analyzing the encoded frame information and separating the encoded frame information into at least one of a faulty channel encoded bit stream, a normal channel encoded bit stream, a short-time average, transmission mode information, and sensor status information;
A first decoder for losslessly decoding the normal channel encoded bit stream and outputting a normal channel signal;
A second decoder for losslessly decoding the error-coded bit-stream and outputting a failure channel signal;
A fault channel signal post-processor for performing post-processing on the fault channel signal output from the second decoder using the short-time average; And
A multiplexer for reconstructing the sensor signal using the post-processed fault channel signal, the normal channel signal, the transmission mode information, and the sensor state information;
And a decoder for decoding the acoustic sensor signal. 6. The method of claim 5,
If the transmission mode information is off, the multiplexer reconfigures the array sensor signal by setting the failure channel signal to a value of 0, and when the transmission mode information is on, the multiplexer uses the postprocessed failure channel signal And reconstructing the array sensor signal. 6. The method of claim 5,
Wherein the first decoder and the second decoder are MPEG-4 ALS decoders. 6. The method of claim 5,
The fault channel signal post-
And outputs the sum of the short-time average and the error channel signal to the decoder. A failure detection is performed on an array sensor signal input from a sensor array to separate a normal channel signal into a faulty channel signal and a lossless coding in the case of a normal channel signal. In the case of a faulty channel signal, A coding apparatus which does not code or performs lossless coding after preprocessing; And
And separates the encoded frame information generated by the encoding device into at least one of a fault channel encoded bit stream, a normal channel encoded bit stream, a short-time average, transmission mode information, and sensor status information, And performs post-processing using the short-time average after lossless decoding in the case of a faulty channel-encoded bitstream, and performs post-processing using the post-processed error channel signal, normal channel signal, transmission mode information, A decoding device for reconstructing an array sensor signal;
And a lossless encoding / decoding process for the acoustic sensor signal. 10. The method of claim 9,
Wherein:
And outputs only the transmission mode information without encoding the fault channel signal if the transmission mode is set to the ON state and lossless coding after performing the preprocessing on the fault channel signal, . 11. The method of claim 10,
The pre-processing may include calculating a short-time average for the failed channel signal, converting the short-time average to an integer value by scalar quantization and dequantization, and subtracting the converted short-time average from the fault channel signal And a signal processing unit for processing the signal. 12. The method of claim 11,
Wherein the post-processing adds the short-time average to the fault channel signal. ≪ RTI ID = 0.0 > [10] < / RTI >

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