Anti-interference target acoustic feature positioning system and method

Abstract

The invention provides an anti-interference target acoustic feature positioning system and method, the system comprises a processing unit, an acoustic system, a position sensor and an attitude sensor, and the method comprises the following steps: the position sensor and the attitude sensor respectively send detection position information and detection attitude information of the acoustic system to the processing unit; the acoustic system sends echo data for detecting the underwater target to the processing unit; and the processing unit processes the echo data according to the detection position information and the detection attitude information to obtain acoustic feature positioning of the underwater target. Through reforming processing and fusion calculation of the position information and the attitude information, the influence of the wind wave interference on the target echo information is corrected, the obtained target positioning information is more accurate, and the influence of the wind wave interference on the target positioning information is smaller.

Description

[Technical field]

[0001] The present invention relates to the technical field of underwater detection engineering equipment, and in particular to an anti-interference target acoustic feature positioning system and method. [Background technology]

[0002] With the rapid development of the marine economy, target detection and positioning systems are playing an increasingly important role. In marine economic activities such as marine exploration, maritime search and rescue, offshore wind power, and offshore oil and gas resources, from nearshore to offshore, the positioning accuracy requirements for detection and positioning systems are constantly increasing.

[0003] In offshore wind power activities, the positioning of submarine cables based on their acoustic characteristics is critical for the status monitoring, operation and maintenance of submarine cables. In the offshore oil and gas resources industry, the positioning of submarine oil and gas pipelines, submarine boulders and other targets is critical for marine engineering construction, oil and gas pipeline laying, and offshore platform construction. In the process of maritime search and rescue, the positioning of underwater targets such as sunken ships and people who fall into the water is critical for emergency rescue.

[0004] In the process of marine economic development, there are many ways to locate underwater targets. One is that the target has its own satellite navigation equipment, fiber optic inertial navigation, etc., relying on external sensor information to complete the combined navigation type target positioning, and the other is that the target has its own acoustic beacon and relies on the beacon sound or external sound source to complete the target positioning. The above positioning methods all rely on the cooperation of the target. In the case of underwater electromagnetic signal shielding, non-cooperation and no acoustic beacon, the above methods will not work.

[0005] The above shortcomings can be well solved by using an acoustic target detection system to complete target positioning based on the target acoustic characteristics. When the acoustic system is used for underwater target positioning, it is necessary to detect the information of the underwater target through sound waves. The acoustic characteristic information of the target includes the acoustic echo intensity, frequency information, phase information, and the echo waveform, two-dimensional sound image, three-dimensional sound image, etc. formed by the combination of these information. Through these acoustic characteristic information, we can distinguish the type, position, scale, etc. of the target. For the required target, we can confirm the target according to the acoustic characteristics based on the target position, acoustic transducer position, and the relative position relationship of the ship, and perform target positioning calculations.

[0006] In the existing technology, the process of using the target acoustic feature positioning is currently mainly based on the assumption that the carrying platform is in uniform linear motion. In actual marine operations, ships and acoustic transducers are affected by wind, waves, currents, tides, etc., resulting in position deviations and attitude deviations of the acoustic system relative to the ideal track when in motion. These deviations are collectively referred to as motion deviations, which cause significant interference to the target acoustic feature positioning.

[0007] The interference caused by wind, waves, currents and ship movement causes the acoustic characteristic information of the target to be offset, deformed, defocused, etc. due to motion deviation during acoustic detection, affecting the detection effect. At the same time, the positioning calculation of the target will also produce a large deviation, and in severe cases, the result accuracy will be too poor to be used. The traditional uniform linear motion assumption cannot meet the requirements of target acoustic characteristic positioning in an interference environment.

[0008] In order to solve the above problems, the present invention proposes an anti-interference target acoustic feature positioning system and method. [Summary of the invention]

[0009] The present invention proposes an anti-interference target acoustic feature positioning system and method. Based on the motion sensor information, the motion deviation of the system is estimated and fused with the actual observation value, and finally the motion trajectory of the system is accurately estimated, breaking the uniform linear motion assumption, and then the real motion trajectory is fused with the acoustic feature calculation process to form a high-resolution acoustic feature image. Finally, the target is determined according to the target acoustic feature image, and the target positioning calculation is performed to obtain the target's high-resolution acoustic features and the target's high-precision position.

[0010] The first aspect of the present invention provides an anti-interference target acoustic feature positioning system, which is used for various platforms such as ships and aircraft, and is used to calculate the acoustic feature image of the target to realize the target acoustic feature positioning of the underwater target, including a processing unit, and an acoustic system, a position sensor and a posture sensor respectively connected to the processing unit, the position sensor and the posture sensor are respectively connected to the acoustic system, the acoustic system is used to send a detection sound wave and receive an echo signal, and the echo signal is a signal returned after the detection sound wave reaches the underwater target; wherein,

[0011] The position sensor and the attitude sensor are used to obtain the position information and attitude information of the acoustic system respectively and send them to the processing unit; the acoustic system here mainly refers to the position of the transmitting transducer and the receiving transducer of the acoustic system. Since the position sensor is rigidly connected to the transmitting transducer and the receiving transducer, it is generally required that the position sensor, the transmitting transducer and the receiving transducer are installed at the same horizontal position to reduce the position deviation caused by the installation error and reduce the difficulty of calibration;

[0012] The acoustic system is used to detect echo data of underwater targets and send the echo data to the processing unit;

[0013] The processing unit is used to process the echo data, the position information and the attitude information to obtain an acoustic feature image of the underwater target and locate the target according to the acoustic characteristics of the target.

[0014] A second aspect of the present invention provides an anti-interference target acoustic feature positioning method, which is used in the anti-interference target acoustic feature positioning system as described in the first aspect, wherein the system includes a processing unit, an acoustic system, a position sensor, and a posture sensor, and the method includes:

[0015] The position sensor and the posture sensor send the position information and posture information of the acoustic system to the processing unit respectively;

[0016] The acoustic system sends echo data of detecting underwater targets to the processing unit;

[0017] The processing unit processes the underwater target echo data, the detection position information and the detection attitude information to obtain the acoustic image features of the underwater target and calculate the target acoustic feature positioning.

[0018] The anti-interference target acoustic feature positioning system and method provided by the present invention include a processing unit, an acoustic system, a position sensor and a posture sensor, and the method includes: the position sensor and the posture sensor respectively send the detection position information and detection posture information of the acoustic system (mainly a transmitting transducer, a receiving transducer, etc.) to the processing unit; the acoustic system sends the echo data of the underwater target to the processing unit; the processing unit processes the echo data according to the detection position information and the detection posture information to obtain the acoustic feature positioning of the underwater target. By reorganizing and fusing the position information and the posture information, the influence of wind and wave interference on the target echo information is corrected. Since the detected position information and posture information are taken into account in the calculation process, the obtained acoustic feature positioning is more accurate and the result quality is higher. At the same time, the calculation process omits the step of correcting the acoustic feature positioning result after calculation, and since the acoustic system position and the acoustic system posture information are taken into account in the calculation process, the echo signal irrelevant to the target can be suppressed, and the influence of wind and wave interference is less, reducing the blurring, defocusing and other problems caused by wind and wave interference.

Brief Description of the Drawings

[0019] Figure 1 A schematic diagram of the structure of the anti-interference target acoustic feature positioning system provided by the present invention;

[0020] Figure 2 Flow chart of the anti-interference target acoustic feature positioning method provided by the present invention:

[0021] Figure 3 A detection schematic diagram of a posture sensor in the anti-interference target acoustic feature positioning system provided by the present invention;

[0022] Figure 4 It is a schematic diagram of the values ​​of the position sensor in the anti-interference target acoustic feature positioning system provided by the present invention after abnormal processing;

[0023] Figure 5 A schematic diagram of a data reorganization processing method in an anti-interference target acoustic feature positioning system provided by the present invention;

[0024] Figure 6 A schematic diagram of a target area detected by an acoustic transducer in the anti-interference target acoustic feature positioning system provided by the present invention;

[0025] Figure 7 A flow chart of a preferred embodiment of the anti-interference target acoustic feature positioning method provided by the present invention. [Specific implementation method]

[0026] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0027] The present invention provides an anti-interference target acoustic feature positioning system and method. First, the relevant concepts of the present invention are clarified as follows:

[0028] The "interference" referred to in the present invention refers to the fact that during the navigation of ships, aircraft and other platforms, the platforms are affected by wind, waves, currents, tides, movement, etc., which causes position deviation and attitude deviation of the acoustic system relative to the ideal track, affecting the calculation of acoustic characteristics and target acoustic positioning.

[0029] The "target" referred to in the present invention refers to the target detected by the acoustic system carried on the platform, such as underwater cables, underwater objects, underwater pipelines, underwater sunken ships, etc.

[0030] The "acoustic features" referred to in the present invention refer to the target echo data obtained by the acoustic system when performing acoustic detection on underwater targets. After signal enhancement and feature calculation, the target acoustic feature data information is obtained. The target acoustic features include various types of information such as target echo curves and target acoustic feature images.

[0031] The "positioning" referred to in the present invention refers to the calculation process of detecting the detected target and obtaining the position and image information of the detected target based on the acquired acoustic feature information.

[0032] like Figure 1As shown, the present invention provides an anti-interference target acoustic feature positioning system, which is used for platforms such as ships and aircraft to realize acoustic feature detection of underwater targets, target position positioning, etc., and includes a processing unit 10, and an acoustic system 20, a position sensor 30, and a posture sensor 40 respectively connected to the processing unit 10. In addition, a data transmission subsystem 50 is used to transmit data from the posture sensor 40, the position sensor 30, and the acoustic system 20 to the processing unit 10 and the data storage subsystem 60. The data storage subsystem 60 is used to store data such as echo data, posture data, position data, target feature data, and target positioning data output by the acoustic system 20, the posture sensor 40, the position sensor 30, and the processing unit 10.

[0033] First, the system architecture in the embodiments of the present application is described.

[0034] Optionally, the acoustic system 20 includes the following subsystems:

[0035] Sound wave generation subsystem: sound wave transmitting transducer 21, transmitting transducer driving module 22;

[0036] Sound wave receiving and converting subsystem: sound wave receiving transducer array 23, multi-channel sound wave receiving subsystem 24.

[0037] Among them, the sound wave generation subsystem is used to generate and transmit sound waves for detection. The sound wave transmitting transducer driving module 22 generates a specific sound wave signal and drives the sound wave transmitting array to transmit the sound wave. The present invention can use the following three signal forms, or other signal forms.

[0038] Signal form 1

[0039]

[0040] Where T is the pulse width and f0 is the frequency

[0041] Signal form 2

[0042]

[0043] K=B / T

[0044] Where T is the pulse width, f0 is the frequency, and B is the signal bandwidth

[0045] Signal form 3

[0046]

[0047] Where T is the pulse width, d1 and f2 are the start and end frequencies of the signal

[0048] The system may select any one of the above signals, or other signal forms. In the following description, the transmission signal is uniformly represented by e0.

[0049] The multi-channel sound wave receiving subsystem 24 is used to receive acoustic echoes of underwater targets. The echoes of the targets are converted into electrical signals through the sound wave receiving transducer array 23, and the signals are conditioned and collected by the multi-channel sound wave receiving subsystem 24, and transmitted to other subsystems such as the processing unit 10 and the data storage subsystem 60 for calculation, storage, and processing.

[0050] Furthermore, the position sensor 30, together with the position anomaly processing method and the position resetting method running in the processing unit 10, constitute an acoustic transducer real track dead reckoning subsystem. The attitude sensor 40, together with the attitude anomaly processing method and the attitude resetting method running in the processing unit 10, constitute an acoustic transducer attitude dead reckoning subsystem.

[0051] Among them, the acoustic transducer track calculation subsystem is used for the precise spatial position of the acoustic system, and the position sensor is used to obtain the position information of the acoustic system, and perform fine processing through a position anomaly processing method and a position reorganization method.

[0052] The acoustic transducer attitude estimation subsystem is used to accurately calculate the attitude information of the acoustic system, and the attitude sensor is used to obtain the attitude information of the acoustic system and perform refined processing through an attitude anomaly processing method and an attitude resetting method.

[0053] Preferably, the anti-interference target acoustic feature positioning system also includes the following subsystems:

[0054] Target echo signal enhancement subsystem: processing unit 10, target echo signal enhancement processing method executed in processing unit 10;

[0055] Target acoustic feature calculation subsystem: processing unit 10, target acoustic feature calculation method running in processing unit 10;

[0056] Target positioning subsystem: processing unit 10, target positioning method running in processing unit 10.

[0057] The target acoustic characteristic calculation subsystem is used for calculating the acoustic characteristics of underwater targets. The target data information obtained in the above process is input into the processing unit, and the target acoustic characteristic calculation method is used for calculation to generate target acoustic characteristic data.

[0058] The target positioning subsystem is used for underwater target positioning. The target acoustic feature data obtained in the above process is input into the processing unit, and the positioning result of the underwater target is obtained by calculation through the target positioning method.

[0059] Based on the above preferred system architecture, Figure 1 As shown, the structure of the anti-interference target acoustic feature positioning system provided in the embodiment of the present application is as follows:

[0060] The position sensor 30 and the attitude sensor 40 are respectively connected to the acoustic system 20; wherein, the position sensor 30 and the attitude sensor 40 are respectively used to obtain the detection position information and detection attitude information of the acoustic system 20 and send them to the processing unit 10; the acoustic system 20 is used to detect the echo data of the underwater target and send it to the processing unit 10; the processing unit 10 is used to process the echo data according to the detection position information and the detection attitude information, mainly including reorganizing the position information and attitude information data, processing the position and attitude information anomalies, and eliminating the influence of abnormal data points; calculating the acoustic feature coverage range according to the reorganized data and acoustic system parameters; performing enhancement calculation on the echo data, and using the data to perform acoustic feature calculation on the acoustic feature coverage range, and finally obtaining the acoustic feature positioning of the underwater target.

[0061] Optionally, the acoustic feature positioning of underwater targets referred to in the embodiments of the present application refers to calculating the acoustic feature information of underwater targets based on target echo information, determining the target based on the target acoustic features, and calculating the underwater target position and target acoustic image information after fusing the platform's real track information. These position and acoustic image information can be presented in a variety of ways, such as data sets, charts or images.

[0062] In this embodiment, after the position sensor 30 and the attitude sensor 40 obtain the position information and attitude information of the acoustic system 20 respectively, they are sent to the processing unit 10, and the processing unit 10 performs data reorganization calculation according to the detection position information and the detection attitude information to obtain the position information and attitude information data after the abnormality processing. After the acoustic system 20 sends the echo data to the processing unit 10 to which it belongs, the processing unit performs echo enhancement calculation to obtain enhanced echo data, and at the same time integrates the position information and attitude information data after the abnormality processing, and processes the echo data to obtain the acoustic characteristic information of the underwater target. The underwater target is determined according to the acoustic image characteristics, and the processing unit 10 calculates and obtains the position and acoustic image information of the underwater target to complete the acoustic image feature positioning of the underwater target. As a result, the detection position information and the detection attitude information directly participate in the processing process of acoustic characteristics and target positioning, instead of assuming that the acoustic system 20 moves in a uniform straight line as in the prior art, and then performing error correction through the position information and attitude information after calculating the three-dimensional detection results. Since the detected position information and attitude information are taken into account during the calculation process, the obtained three-dimensional detection is more accurate and the image quality is higher. At the same time, the calculation process eliminates the step of correcting the image after calculation, and since the position and attitude information are taken into account during the calculation process, irrelevant signals can be filtered out, the calculation amount is smaller, the calculation effect is higher, and the ability to resist interference such as non-target echoes is stronger.

[0063] like Figure 1 As shown, the acoustic feature positioning system provided by the present invention also includes a data transmission subsystem 50 and a data storage system 60, wherein the acoustic system 20 includes a sound wave generation subsystem and a sound wave receiving conversion subsystem, wherein the sound wave generation subsystem includes a sound wave transmitting transducer 21 and a transmitting transducer driving module 22, and the sound wave receiving conversion subsystem includes a sound wave receiving transducer array 23 and a multi-channel sound wave receiving subsystem 24. In the specific working process, the transmitting transducer driving module 22 transmits the detection sound wave through the sound wave transmitting transducer 21 during the navigation of the aircraft, and the sound wave receiving transducer array 23 is used to receive the echo data, and the echo data includes the echo sound wave after the detection sound wave reaches the underwater target. The multi-channel sound wave receiving subsystem 24 sends the echo data to the data transmission subsystem 50, and the data transmission subsystem 50 transmits the echo data to the processing unit 10 for processing. The processing unit 10 stores the acoustic feature positioning after the processing in the data storage subsystem.

[0064] It should be noted that Figure 1The architecture shown is a preferred embodiment, and its specific implementation is not limited. For example, the processing unit 10 can have multiple implementations, for example, the processing unit 10 can be a data processing subsystem arranged on the aircraft, or the processing unit 10 can also adopt a distributed design, with one part arranged on the underwater acoustic system 20 and the other part arranged on the aircraft. The present invention is not limited to this.

[0065] Based on the above system, the present invention further provides an anti-interference target acoustic feature positioning method, such as Figure 2 As shown, the method includes:

[0066] 100. The position sensor and the attitude sensor send the detected position information and the detected attitude information of the acoustic system to the processing unit respectively. In this embodiment, the position sensor and the attitude sensor periodically detect the real-time position and attitude during the navigation of the aircraft. The position sensor is used to detect the geographical location information of the acoustic system, such as the coordinate information of the location, and the attitude sensor is used to detect the attitude information of the acoustic system. Preferably, Figure 3 As shown, the attitude sensor is used to measure the three attitude quantities of the acoustic system: roll, pitch and yaw.

[0067] Optionally, for the acquired sensor data, a sensor data pair may be established.

[0068] <tsensor(k,p),vsensor(k,p)>

[0069] Since there are multiple sensor information, such as position information, speed information, attitude information, etc., and the collection time of each sensor is different, there will be multiple sets of sensor data. For example, the above sensor data pair represents the p-th sensor (such as roll), the k-th data collected (that is, the number of data collected), the corresponding collection time is tsensor(k,p), and the corresponding sensor value is vsensor(k,p).

[0070] For example, if there are five types of sensor data (such as position, speed, roll, pitch, and yaw), then p can be 0, 1, 2, 3, or 4. The data of each sensor is a time series function, which can be expressed as S p (t p ),in

[0071] Collection time t p =tsensor(k,p), value S p =vsensor(k,p);

[0072] Furthermore, due to the working environment and the sensor itself, sensor data often produces abnormal values, and it is necessary to perform an abnormality removal operation on the above sensor data sequence. The specific steps are as follows.

[0073] S p (j) represents the jth data in the sequence, and performs the outlier removal operation on it.

[0074]

[0075] Where mid(S p (j),10) means taking S p (j), the window size can be taken as a reference value of 10, that is,

[0076] S p (j-9), S p (j-8), ..., S p (j-1), S p The median value in (j) is removed and the new sequence S1 is obtained after outlier processing p

[0077] In order to further remove the interference of noise, the above S1 p Further operation, taking the sampling window as the reference value 10, the reshaped sensor data is

[0078]

[0079] The schematic diagram of the track after filtering is as follows: Figure 4 As shown in the figure, the dotted track after filtering removes the interference of noise, is smoother than the track originally measured by the sensor, has no sudden changes, and is closer to the actual track of the aircraft.

[0080] 200. The acoustic system sends echo data of detecting underwater targets to the processing unit.

[0081] In this embodiment, the transmitting transducer of the acoustic system continuously and periodically transmits detection sound waves during the navigation of the aircraft. Preferably, the detection sound waves are sound wave frequencies set by the user (the user sets the center frequency and signal bandwidth, and the sound waves meet the user's setting requirements). After the detection sound waves reach the underwater detected target, they return and are received by the receiving transducer of the acoustic system, which is the echo data. The acoustic system sends the echo data to the processing unit for acoustic feature calculation processing.

[0082] 300. The processing unit processes the echo data according to the detection position information and the detection attitude information to obtain acoustic characteristic information of the underwater target.

[0083] In this embodiment, since the sensor data collection time and the acoustic system working time are not always completely consistent, the sensor reading frequency is generally lower than the acoustic system data frequency, and after the abnormal processing operation, the above sequence S2 p The acquisition time and the period t of the acoustic system i Therefore, it is necessary to perform time synchronization and alignment processing on the detection position information and the detection attitude information respectively with the echo data, so that each group of echo data in the echo data is at the same time as the corresponding position data and attitude data, in order to improve the accuracy of subsequent acoustic feature positioning.

[0084] It should be noted that the present invention does not limit the specific processing method of time synchronization alignment. Preferably, time alignment can be performed in the following manner.

[0085] 311. The processing unit obtains a sensor data pair, where the sensor data pair includes the detection position information and the detection posture information.

[0086] In this embodiment, the sensor data pair is the sensor data pair established in the aforementioned step 100.

[0087] <tsensor(k,p),vsensor(k,p)> , which includes information in multiple dimensions obtained by position sensors and attitude sensors.

[0088] 312. The processing unit reorganizes the values ​​in the sensor data pair so that the detection position information and the detection attitude information are respectively aligned with the echo data in time synchronization.

[0089] In this embodiment, the time alignment of data is achieved through reorganization. Figure 5 As shown, Figure 5 Each square in represents a data frame, wherein the acoustic system acquires 2 frames of echo data per second, but the position sensor and attitude sensor only acquire 1 frame of data per second. At this time, through the reorganization process, Figure 5 The data frame shown in the dotted box makes the sensor data have 2 frames of data per second, so that the number of echo data is consistent with that of sensor data, thereby achieving time alignment of the detection position information and the detection attitude information with the echo data respectively.

[0090] It should be noted that, due to the above operations, the sensor data corresponding to the echo data is a set of observation values ​​with systematic errors, which affects the accuracy of positioning. Therefore, preferably, after the above step 300, the following steps are also performed.

[0091] 320. The processing unit performs optimal estimation on at least one of the detection position information or the detection attitude information that are time-aligned with the echo data to determine accurate position data and / or attitude data at each echo moment.

[0092] In this embodiment, in order to obtain the latest sensor data corresponding to the echo data at the same time, it is necessary to combine the historical sensor data and the current observation value to obtain the latest sensor data corresponding to the echo data at the same time. i The optimal estimate is made at all times to obtain accurate sensor data for subsequent calculations.

[0093] Preferably, step 320 includes the following steps.

[0094] 321. Set the assumed position of the acoustic system at the time of echo in a state of uniform linear motion.

[0095] During the movement of the acoustic system, it will be disturbed by wind, waves and currents and cannot reach the ideal uniform linear state. The following method is used to calculate the actual position of the system. Assume that the actual position of the system at time i is Spos i Due to the existence of motion error and system observation error, we cannot obtain the accurate system position. We can only obtain the observed position value obtained by the position sensor, denoted as Z i .

[0096] Considering the position on the horizontal plane, the position model of the acoustic system can be expressed as

[0097]

[0098] where x i and i is the plane coordinate, vx i and vy i are two coordinate velocities, and the state transition matrix after ΔT is recorded as

[0099]

[0100] Then the predicted value of the actual position at the next moment, that is, moment i+1, is

[0101]

[0102] It should be noted that the position sensor may be, for example, a GPS, etc., which can directly obtain coordinate information. Without considering the speed value, the position observation model of the acoustic system is expressed as:

[0103]

[0104] 322. Error propagation of the system based on the initial error calculation between the detected position information and the actual position information at the initial echo moment.

[0105] In this embodiment, during the navigation of the aircraft, multiple cycles of detection are required, and the system will obtain echo data, detection position information and detection attitude information once in each cycle. Since there is an error between the detection position information after reorganization processing in each cycle and the actual position of the acoustic system, the error is transferred. In this regard, the calculation for error transfer is as follows.

[0106] Set the initial error to:

[0107]

[0108] The error transfer calculation formula for determining the system is:

[0109]

[0110] Among them, P i is the error of the previous echo time, at the initial echo time P i =P0; As the error accumulates, the new error is substituted into the above formula (7) to obtain the error value corresponding to each echo cycle. The above Q is the estimated error,

[0111] It can be adjusted according to the specific system conditions. The reference value of Q is given below:

[0112]

[0113] 323. Determine a system gain value according to the real-time error obtained by the error transmission.

[0114] On the basis of clarifying the error transmission, the system gain of this echo cycle can be determined according to the real-time error, so as to compensate the error. The system gain value can be recorded as:

[0115]

[0116] Where R is the variance of the mean of the observed noise; it can be adjusted according to the system, and the reference value of R is given below

[0117]

[0118] 324. Predict a predicted position value of the acoustic system at the next echo moment according to the assumed position of the acoustic system and the system gain value.

[0119] In this embodiment, by calculating the motion state of the acoustic system under the interference of wind, waves and currents, determining its assumed position according to its observed position value containing motion error, and further calculating its system gain value, the real position information of the system at the next moment can be obtained as Spos. i+1 ,

[0120]

[0121] Among them, Z_(i+1) is the observation value of the position sensor.

[0122] The initial value of the acoustic system position information and the system observation value are iterated according to the above process, that is, the real and precise position of the system can be estimated through the historical estimation value and the current observation value, so as to accurately know the position information of the acoustic system at each echo moment.

[0123] It should be noted that when entering the calculation of the next round of echo time, the calculation result of the above formula (7) needs to be converted into the error of this round. Substitute the following formula to obtain the P at the next echo moment: i+1 for:

[0124]

[0125] In the next round of error propagation calculation, the above P i+1 Substituting the value of into the above formula (7), the error value of the next round can be calculated.

[0126] It should be noted that the above steps predict precise position information by detecting position information, thereby improving the accuracy of position information. The reason is that in the process of acoustic feature calculation, position information has a relatively large impact on the result, so the detected position information is predicted in a targeted manner. In the actual working process, according to actual needs, precise posture information can be further predicted based on the detected posture information, thereby further improving the accuracy of detection. The specific implementation method of predicting precise posture information based on the detected posture information can refer to the above-mentioned method of predicting precise position information, and the present invention will not repeat it.

[0127] Furthermore, after the accurate position of the echo moment is determined through the above steps, the following method is further executed to calculate the acoustic characteristics.

[0128] First, the target echo is enhanced to improve its signal-to-noise ratio and the resolution of the echo time dimension (or equivalently the distance dimension). Assume

[0129] The echo corresponding to the qth receiving sub-matrix is ​​e(t,q), where t represents the receiving time and q represents the number of the sub-matrix.

[0130] Assuming the transmitted signal is e0, the enhancement process is

[0131] The signal after enhancement processing is

[0132] erc(t,q)=IFFT(FFT(e(t,q))×FFT * (e0))

[0133] FFT and IFFT represent Fourier and Inverse Fourier Transform respectively, and * represents the conjugate of the signal.

[0134] 330. The processing unit calculates target acoustic features according to the time-aligned detection position information, the detection attitude information and the echo data.

[0135] In this embodiment, since the acoustic position used in the acoustic feature calculation process is an actual position that has been accurately predicted, the obtained result is more accurate and less affected by wind and waves. The above step 330 specifically includes the following steps.

[0136] 331 determines the coordinate value of each receiving subarray in the acoustic system according to the predicted position value of the acoustic system.

[0137] In this embodiment, based on the prediction of the position of the acoustic system, combined with the information such as the speed and satellite positioning in the sensor, the precise geographic coordinates bx(i), by(i), bz(i) of the acoustic system can be determined.

[0138] According to the coordinates, the coordinates of the transmitting transducer and the receiving transducer of the acoustic system can be calculated, and the specific method is as follows.

[0139] Assume t i The rotation sensor data information at the time is recorded as

[0140] yaw=α

[0141] pitc=β

[0142] roll=γ (13)

[0143] The rotation matrix is ​​denoted as

[0144]

[0145] Calculate t i The position of the transmitting transducer at time tx(i), ty(i), tz(i). Assuming that the coordinates of the transmitting transducer in the acoustic system coordinate system are tx0, ty0, tz0, then

[0146]

[0147] According to the above steps, get ti The positions of the receiving transducers at time instant are rx(i,q),ry(i,q),rz(i,q), where q represents the qth receiving subarray. Assume that the coordinates of the qth receiving subarray in the acoustic system coordinate system are rx q0 ,ry q0 ,rz q0 ,but:

[0148]

[0149] Therefore, through the above method, the coordinates of the transmitting transducer and each receiving sub-array in the receiving transducer in the acoustic system are determined.

[0150] Furthermore, according to the position information and attitude information of the acoustic system obtained by the above calculation, the target coverage range of the acoustic system can be further calculated.

[0151] Since the transducer of the acoustic system has a certain opening angle range, the target area it detects has a certain range. However, the acoustic transducer in the ideal motion state and the acoustic transducer in the wind wave current state have different positions and postures, so the target areas they detect are different. Figure 6 shown.

[0152] Therefore, it is necessary to calculate the target area to be detected based on the position information and attitude information of the acoustic system. Assume that at a certain time t, the target area detected by the acoustic system is B t , assuming that at this moment, the position information and attitude information obtained according to the above calculation is TP t , which is a collection of information about the position and attitude of the acoustic transducer.

[0153] The relationship between the transducer opening angle and the geometric position can be used to calculate the target area to be detected.

[0154] B t =F trans (TP t )

[0155] where F trans is the geometric mapping function of the acoustic system, which is only related to the transducer opening angle of the system and can be obtained based on the geometric position relationship, which will not be described in detail here.

[0156] After the target area actually detected by the acoustic system is determined, the echo data of the receiving subarrays can be superimposed according to the acoustic characteristic grid of the target area. The detailed steps are as follows.

[0157] 332 The echo data of each receiving subarray of the acoustic system are superimposed according to the coordinate value to obtain the acoustic characteristic result of the underwater target.

[0158] In this embodiment, after superimposing the data of each receiving subarray, the acoustic feature result can be obtained, and the specific method is as follows.

[0159] The echo corresponding to the qth receiving sub-matrix is ​​e(t,q), where t represents the receiving time and q represents the number of the sub-matrix.

[0160] The echo enhancement processing corresponding to the qth receiving subarray is erc(t,q)

[0161] The detection method for point P is as follows. Assuming the physical coordinates of point P are xp, yp, zp, the acoustic feature information is the superposition of the data of each receiving subarray. During the calculation process, point P should be within the target coverage range B calculated above at that moment. t within, that is

[0162] I P =∑ q erc(t-Δt,q)(I P ∈B t ) (17)

[0163] The time delay Δt is the transmission delay from the transmitting transducer and the receiving transducer to the target, and the calculation method of Δt is as follows.

[0164]

[0165] As a result, after the processing unit performs superposition processing on the data of each receiving sub-array, the acoustic characteristic results of the space can be further obtained.

[0166] 333 The target is further located by the above acoustic feature results. The acoustic feature data calculated by the above is I P The set of (xp, yp, zp) first reduces the dimension of the data

[0167]

[0168] The target is positioned by using a target positioning algorithm, such as using an extreme value algorithm to locate the target with the largest acoustic eigenvalue. xy (xp,yp) finds the maximum value row by row and obtains the coordinate sequence

[0169] (X max ,Y max )

[0170] This is the horizontal positioning of the target. Then, based on this set, the acoustic feature data is selected to obtain

[0171] I yz (yp,zp)=I P (xp,yp,zp)[(xp,yp)∈(X max ,Ymax )]

[0172] Similarly, for the two-dimensional matrix I yz (yp,zp), find the maximum value in the z direction and get the coordinate sequence

[0173] (Y max ,Z max )

[0174] is the vertical positioning of the target,

[0175] Based on the above, we can get the target positioning result.

[0176] (X max, Y max ,Z max )

[0177] The above is a detailed description of each step of the present invention for ease of understanding. Figure 7 As shown, a preferred embodiment is further provided as follows, which records the complete process of the present invention and is described in detail as follows.

[0178] 1. Obtain the position information of the acoustic system through the position sensor.

[0179] 2. Obtain the attitude information of the acoustic system through the attitude sensor.

[0180] 3. Perform outlier processing on the location information, including removing outliers.

[0181] 4. Remove anomalies from the posture information, including removing outliers.

[0182] 5. Obtain echo data through the receiving transducer.

[0183] 6. Determine the time of each echo.

[0184] 7. Reorganize the detection position information and detection attitude information with the echo data respectively.

[0185] 8. Obtain the position data and attitude data corresponding to each echo moment based on the reorganized data.

[0186] 9. Get echo information.

[0187] 10. Enhance the echo information.

[0188] 11. Determine the target area that the acoustic system actually detects.

[0189] 12. Superimpose the echo data of each receiving subarray of the acoustic system according to the position data and attitude data at each echo moment.

[0190] 13. Calculate the acoustic feature information within the target area.

[0191] 14. Determine the target positioning result based on the acoustic feature information.

[0192] 15. Output target positioning results.

[0193] The specific implementation of the above steps 1 to 14 can be found in the previous description and will not be repeated here.

[0194] In summary, the present invention provides an anti-interference target acoustic feature positioning system and method, the system includes a processing unit, an acoustic system, a position sensor and a posture sensor, and the method includes: the position sensor and the posture sensor send the detection position information and detection posture information of the acoustic system to the processing unit respectively; the acoustic system sends the echo data of the underwater target to the processing unit; the processing unit processes the echo data according to the detection position information and the detection posture information to obtain the acoustic feature positioning of the underwater target. By reorganizing and fusing the position information and posture information, the influence of wind and wave interference on the target echo information is corrected. Since the detected position information and posture information are taken into account in the calculation process, the obtained acoustic feature positioning is more accurate and the result quality is higher. At the same time, the calculation process omits the step of correcting the acoustic feature positioning result after calculation, and since the position and posture information are taken into account in the calculation process, irrelevant signals can be filtered out and the influence of wind and wave interference is less.

[0195] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An anti-interference target acoustic feature positioning system, used for ships or aircraft, to achieve target acoustic feature positioning of underwater targets, characterized in that: It includes a processing unit, and an acoustic system, a position sensor and a posture sensor respectively connected to the processing unit, the position sensor and the posture sensor are respectively connected to the acoustic system, the acoustic system is used to send a detection sound wave and receive an echo signal, and the echo signal is a signal returned after the detection sound wave reaches the underwater target; wherein, The position sensor and the attitude sensor are used to respectively obtain the detection position information and the detection attitude information of the acoustic system and send them to the processing unit; The acoustic system is used to detect echo data of underwater targets and send the echo data to the processing unit; The processing unit is used to process the echo data according to the detection position information and the detection attitude information to obtain the acoustic feature positioning of the underwater target.

2. The system according to claim 1, characterized in that The acoustic system includes a sound wave generating subsystem and a sound wave receiving and converting subsystem, wherein: The acoustic wave generation subsystem is used to emit detection acoustic waves during the navigation of the aircraft; The sound wave receiving and converting subsystem is used to receive the echo data, and the echo data includes the echo sound wave after the detection sound wave reaches the underwater target.

3. A method for locating an anti-interference target acoustic feature, used in the anti-interference target acoustic feature locating system as claimed in claim 1 or 2, wherein the system comprises a processing unit, an acoustic system, a position sensor and a posture sensor, characterized in that: The method comprises: The position sensor and the attitude sensor send the detection position information and the detection attitude information of the acoustic system to the processing unit respectively; The acoustic system sends echo data of detecting underwater targets to the processing unit; The processing unit processes the echo data according to the detection position information and the detection attitude information to obtain the acoustic feature positioning of the underwater target.

4. The method according to claim 3, characterized in that The processing unit processes the echo data according to the detection position information and the detection attitude information to obtain the acoustic feature positioning of the underwater target, including: The processing unit performs time alignment processing on the detection position information and the detection attitude information with the echo data respectively, so as to obtain the position data and attitude data corresponding to each echo moment in the echo data; The processing unit calculates the acoustic feature positioning of the underwater target according to the time-aligned detection position information, the detection attitude information and the echo data.

5. The method according to claim 4, characterized in that The processing unit performs time alignment processing on the detection position information and the detection attitude information respectively with the echo data, including: The processing unit acquires a sensor data pair, wherein the sensor data pair includes the detection position information and the detection posture information; The processing unit reorders the values ​​in the sensor data pair so that the detection position information and the detection attitude information are respectively aligned with the echo data in time.

6. The method according to claim 4, characterized in that After the processing unit performs time alignment processing on the detection position information and the detection attitude information with the echo data respectively, the processing further includes: The processing unit performs optimal estimation on at least one of the detection position information or the detection attitude information after time alignment with the echo data, so as to determine accurate position data and / or attitude data at each echo moment.

7. The method according to claim 6, characterized in that The processing unit optimally estimates at least one of the detection position information or the detection attitude information after time alignment with the echo data, including: Setting the assumed position of the acoustic system at the time of the echo in a state of uniform linear motion; The error transfer of the system is calculated based on the initial error between the detected position information and the actual position information at the initial echo time; Determine a system gain value according to the real-time error obtained by the error transmission; Predicting a predicted position value of the acoustic system at the next echo moment according to the assumed position of the acoustic system and the system gain value; The processing unit processes the echo data according to the detection position information and the detection attitude information to obtain the acoustic feature positioning of the underwater target, including: The echo data is processed according to the predicted position value and the detection attitude information to obtain the acoustic feature positioning of the underwater target.

8. The method according to claim 7, characterized in that Assuming that the acoustic system performs uniform linear motion and determining the assumed position of the acoustic system includes: The position model of the acoustic system is determined as: where x i and i is the plane coordinate, vx i and vy i for speed; The state transition matrix after ΔT is recorded as: The assumed position of the acoustic system is determined by the following algorithm: Wherein, without considering the velocity value, the position observation model of the acoustic system is recorded as: The error transfer of the initial error calculation system of the detection position information and the actual position information at the initial echo time includes: Set the initial error to: Determine the error transfer of the system as: Where Q is the estimation error, P i is the error of the previous echo time, at the initial echo time P i =P0; The determining of the system gain value according to the real-time error obtained by the error transmission comprises: The system gain value is recorded as: Where R is the variance of the mean of the observation noise; The predicting the predicted position value of the acoustic system at the echo moment according to the assumed position of the acoustic system and the system gain value comprises: Determine the actual position information of the acoustic system at the next echo time as Spos i+1 , Among them, Z i+1 is the observed value of the position sensor.

9. The method according to claim 8, characterized in that After predicting the predicted position value of the acoustic system at this echo moment according to the assumed position of the acoustic system and the system gain value, the method further includes: The error in determining the next echo time is: The above error value P i+1 Used for error transfer at the next echo moment.

10. The method according to claim 7, characterized in that The echo data is processed according to the predicted position value and the detection attitude information to obtain underwater target acoustic feature positioning, including: Determining a coordinate value of each receiving subarray in the acoustic system according to the predicted position value of the acoustic system; The echo data of each receiving subarray of the acoustic system are superimposed according to the coordinate values ​​to obtain the acoustic feature positioning of the underwater target.

11. The method according to claim 7, characterized in that The method further comprises: A detection target area of ​​the acoustic system is determined according to the predicted position value and the detection posture information.

12. The method according to claim 11, characterized in that The determining the detection target area of ​​the acoustic system according to the predicted position value and the detection posture information includes: Assuming the target time t, the target area detected by the acoustic system is B t , assuming that the target moment, the predicted position value and the detected posture information TP t , the TP t , comprising a collection of the predicted position value and the detected posture information; B t =F trans (TP t ) Among them, F trans is the geometric mapping function of the acoustic system.

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