Underwater Target Velocity Estimation Method, Device and Equipment Based on Underwater Acoustic Positioning System

Abstract

The present invention provides a method, device and equipment for estimating the speed of an underwater target based on an underwater acoustic positioning system. Based on the positioning acoustic signals transmitted by the target moving acoustic beacon and the positioning acoustic signals received by the underwater reference array elements, the time delay result and the signal transmission time interval are determined; based on the time delay result and the signal transmission time interval, the prior information of the target Doppler is determined; the phase difference integer ambiguity is solved by using the prior information of the target Doppler and the signal transmission time interval to determine the initial Doppler estimate value; if the initial Doppler estimate value does not meet the preset decision feedback threshold, the initial Doppler estimate value is corrected by using the prior information of the target Doppler to obtain the current target Doppler estimate value, and then the underwater target speed estimate result is determined. The present invention can accurately estimate the motion speed of an underwater dynamic target, provide Doppler information for real-time motion compensation of the underwater acoustic positioning system, and thus improve the underwater acoustic positioning accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of underwater acoustic positioning, and in particular to a method, device and equipment for estimating the speed of an underwater target based on an underwater acoustic positioning system. Background Art

[0002] In underwater acoustic positioning, due to sea surface wind and waves, ocean turbulence movement, and the relative movement of the transceiver platforms at both ends, the underwater acoustic channel with low sound speed and narrow available bandwidth has a significant Doppler effect, causing the transmitted signal frame to show a certain degree of compression or expansion in the time domain, resulting in difficulties in carrier tracking, cumulative symbol synchronization errors, and low information transmission reliability, seriously affecting the accuracy of underwater acoustic positioning. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a method, device and equipment for estimating the speed of an underwater target based on an underwater acoustic positioning system, which can accurately estimate the movement speed of an underwater dynamic target, provide Doppler information for real-time motion compensation for the underwater acoustic positioning system, and thus improve the accuracy of underwater acoustic positioning.

[0004] In a first aspect, the present invention provides a method for estimating the speed of an underwater target based on an underwater acoustic positioning system. The underwater acoustic positioning system includes a signal processor, a plurality of underwater reference arrays, and a plurality of mobile acoustic beacons. In each working cycle, each mobile acoustic beacon polls and transmits at least two positioning acoustic signals, and each underwater reference array receives the positioning acoustic signals. The method is applied to the signal processor and includes:

[0005] Based on the positioning acoustic signals transmitted by the target mobile acoustic beacon and the positioning acoustic signals received by the underwater reference array in the current working cycle, determine the time delay result and the signal transmission time interval in the current working cycle; wherein, the time delay result includes the time delay value of the target mobile acoustic beacon relative to the underwater reference array;

[0006] Based on the time delay result and the signal transmission time interval in the current working cycle, determine the target Doppler prior information;

[0007] Use the target Doppler prior information and the signal transmission time interval to solve the phase difference integer ambiguity to determine the initial Doppler estimate value in the current working cycle;

[0008] If it is determined according to the target Doppler prior information that the initial Doppler estimate value does not meet the preset decision feedback threshold, then correct the initial Doppler estimate value using the target Doppler prior information to obtain the target Doppler estimate value in the current working cycle;

[0009] Estimate the underwater target speed estimate result in the current working cycle according to the target Doppler estimate value. The underwater target speed estimate result includes the movement speed of the target mobile acoustic beacon relative to the underwater reference array.

[0010] In one embodiment, the signal transmission time interval is the sum of the protection interval duration between two positioning acoustic signals and the duration of the current working cycle; based on the time delay result in the current working cycle and the signal transmission time interval, the target Doppler prior information is determined, including:

[0011] Based on the ratio between the signal peak time interval and the signal transmission time interval, the first Doppler prior information is determined, where the signal peak time interval is the time interval between the peaks of any two positioning acoustic signals sent by the target moving acoustic beacon;

[0012] Based on the time delay result in the current working cycle and the time delay result in the historical working cycle, the distance change between the target moving acoustic beacon and the underwater reference array element in the current working cycle is determined, so as to determine the initial motion speed between the target moving acoustic beacon and the underwater reference array element in the current working cycle, and the second Doppler prior information is determined based on the initial motion speed;

[0013] According to the first Doppler prior information and the second Doppler prior information, the target Doppler prior information is determined.

[0014] In one embodiment, the phase difference integer ambiguity is solved by using the target Doppler prior information and the signal transmission time interval, so as to determine the initial Doppler estimate value in the current working cycle, including:

[0015] The main lobes at the peaks of any two positioning acoustic signals sent by the target moving acoustic beacon are intercepted for phase detection, the first correlation peak phase and the second correlation peak phase are obtained, and the difference between the first correlation peak phase and the second correlation peak phase is used as the correlation peak main lobe phase difference;

[0016] According to the correlation peak main lobe phase difference and the signal transmission time interval, the initial Doppler estimate value is split into a phase integer cycle part and a phase non-integer cycle part;

[0017] The Doppler estimate value corresponding to the phase non-integer cycle part is determined; and, the phase difference integer ambiguity is solved based on the target Doppler prior information, so as to determine the Doppler estimate value corresponding to the phase integer cycle part by using the phase difference integer ambiguity;

[0018] The sum of the Doppler estimate value corresponding to the phase non-integer cycle part and the Doppler estimate value corresponding to the phase integer cycle part is used as the initial Doppler estimate value.

[0019] In one embodiment, the phase difference integer ambiguity is solved based on the target Doppler prior information, so as to determine the Doppler estimate value corresponding to the phase integer cycle part by using the phase difference integer ambiguity, including:

[0020] Determine the phase difference integer ambiguity according to the following formula:

[0021] , ;

[0022] wherein, is the phase difference integer ambiguity, is an intermediate parameter, is the target Doppler prior information, is the frequency, is the signal emission time interval, and [] represents rounding towards zero, is rounding down;

[0023] Determine the Doppler estimate corresponding to the integer cycle part of the phase according to the following formula:

[0024] ;

[0025] wherein, is the Doppler estimate corresponding to the integer cycle part of the phase, is the target Doppler prior information, is the Doppler estimate corresponding to the non-integer cycle part of the phase.

[0026] In one embodiment, before it is determined that the initial Doppler estimate does not meet the preset decision feedback threshold according to the target Doppler prior information, the method further includes:

[0027] If the difference between the target Doppler prior information and the initial Doppler estimate is greater than the preset decision feedback threshold, it is determined that the initial Doppler estimate does not meet the decision feedback threshold.

[0028] In one embodiment, correcting the initial Doppler estimate using the target Doppler prior information to obtain the target Doppler estimate in the current working cycle, including:

[0029] Correct the phase difference integer ambiguity according to the difference between the target Doppler prior information and the initial Doppler estimate to obtain a new phase difference integer ambiguity;

[0030] Determine the Doppler factor correction value based on the new phase difference integer ambiguity;

[0031] Use the sum of the initial Doppler estimate and the Doppler factor correction value as the target Doppler estimate in the current working cycle.

[0032] In one embodiment, after estimating the underwater target speed estimation result in the current working cycle according to the target Doppler estimate, the method further includes:

[0033] According to the underwater target speed estimation result, correct the time delay result in the current working cycle;

[0034] Based on the corrected time delay result, perform positioning calculation through the geometric spherical intersection principle to obtain the real-time positioning result of the target moving acoustic beacon in the current working cycle.

[0035] In a second aspect, the present invention further provides an underwater target speed estimation device based on an underwater acoustic positioning system. The underwater acoustic positioning system includes a signal processor, a plurality of underwater reference arrays, and a plurality of moving acoustic beacons. In each working cycle, each moving acoustic beacon polls and transmits at least two positioning acoustic signals, and each underwater reference array receives the positioning acoustic signals. The device is applied to the signal processor and includes:

[0036] A signal detection module, configured to determine the time delay result and the signal transmission time interval in the current working cycle based on the positioning acoustic signals transmitted by the target moving acoustic beacon and the positioning acoustic signals received by the underwater reference array in the current working cycle; wherein, the time delay result includes the time delay value of the target moving acoustic beacon relative to the underwater reference array;

[0037] A prior information determination module, configured to determine the target Doppler prior information based on the time delay result and the signal transmission time interval in the current working cycle;

[0038] A Doppler estimated value determination module, configured to solve the phase difference integer ambiguity using the target Doppler prior information and the signal transmission time interval to determine the initial Doppler estimated value in the current working cycle;

[0039] A Doppler estimated value correction module, configured to, if it is determined according to the target Doppler prior information that the initial Doppler estimated value does not meet the preset decision feedback threshold, correct the initial Doppler estimated value using the target Doppler prior information to obtain the target Doppler estimated value in the current working cycle;

[0040] A speed estimation module, configured to estimate the underwater target speed estimation result in the current working cycle according to the target Doppler estimated value, and the underwater target speed estimation result includes the movement speed of the target moving acoustic beacon relative to the underwater reference array.

[0041] In a third aspect, the present invention further provides an electronic device, including a processor and a memory. The memory stores computer executable instructions that can be executed by the processor, and the processor executes the computer executable instructions to implement the method according to any one of the first aspect.

[0042] In a fourth aspect, the present invention further provides a computer-readable storage medium, which stores computer executable instructions. When the computer executable instructions are called and executed by the processor, the computer executable instructions cause the processor to implement the method according to any one of the first aspect.

[0043] An underwater target speed estimation method, device and equipment based on an underwater acoustic positioning system provided by the present invention. The underwater acoustic positioning system includes a signal processor, a plurality of underwater reference arrays and a plurality of mobile acoustic beacons. In each working cycle, each mobile acoustic beacon polls and transmits at least two positioning acoustic signals, and each underwater reference array receives the positioning acoustic signals. First, based on the positioning acoustic signals transmitted by the target mobile acoustic beacon and the positioning acoustic signals received by the underwater reference array in the current working cycle, the time delay result and the signal transmission time interval in the current working cycle are determined. The time delay result includes the time delay value of the target mobile acoustic beacon relative to the underwater reference array. Then, based on the time delay result and the signal transmission time interval in the current working cycle, the target Doppler prior information is determined. Next, the phase difference integer ambiguity is solved by using the target Doppler prior information and the signal transmission time interval to determine the initial Doppler estimate value in the current working cycle. If it is determined according to the target Doppler prior information that the initial Doppler estimate value does not meet the preset decision feedback threshold, the initial Doppler estimate value is corrected by using the target Doppler prior information to obtain the target Doppler estimate value in the current working cycle. Finally, the underwater target speed estimation result in the current working cycle is estimated according to the target Doppler estimate value. The underwater target speed estimation result includes the movement speed of the target mobile acoustic beacon relative to the underwater reference array. The above method aims to utilize the acoustic signal intercommunication and positioning mechanism between the underwater reference array and the mobile acoustic beacon to complete Doppler estimation and motion compensation in real time and with low complexity during the positioning process. By creating a dual-positioning acoustic signal system, rough Doppler estimation is performed, and the search space of the phase difference integer ambiguity is further compressed to achieve the rapid and accurate solution of the accurate target Doppler estimate value. The present invention not only has the advantages of low computational complexity, simple operation and high accuracy, but also can accurately estimate the movement speed of underwater dynamic targets, provide Doppler information for motion compensation in the underwater acoustic positioning system in real time, thereby improving the underwater acoustic positioning accuracy.

[0044] Other features and advantages of the present invention will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present invention. The objectives and other advantages of the present invention are achieved and obtained by the structures specifically pointed out in the specification, claims and drawings.

[0045] To make the above objectives, features and advantages of the present invention more obvious and understandable, the following specific preferred embodiments are given, and in conjunction with the accompanying drawings, the detailed description is as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0047] Figure 1 It is a schematic flowchart of a method for estimating the speed of an underwater target based on an underwater acoustic positioning system provided by an embodiment of the present invention;

[0048] Figure 2 It is a block diagram of the algorithm flowchart of a method for estimating the speed of an underwater target based on an underwater acoustic positioning system provided by an embodiment of the present invention;

[0049] Figure 3 It is a schematic diagram of a mobile acoustic beacon sending a positioning acoustic signal provided by an embodiment of the present invention;

[0050] Figure 4 It is a schematic diagram of the lake test scenario setting provided by an embodiment of the present invention;

[0051] Figure 5 It is a schematic diagram of the correlation result of the double LFM positioning signals transmitted in a polling manner by beacon 1 and beacon 2 received by reference element 1 provided by an embodiment of the present invention;

[0052] Figure 6 It is a schematic diagram of the estimated result of the relative motion speed between beacon 1 and reference element 1 provided by an embodiment of the present invention;

[0053] Figure 7 It is a schematic diagram of the estimated result of the relative motion speed between beacon 2 and reference element 1 provided by an embodiment of the present invention;

[0054] Figure 8 It is a schematic diagram of the estimated result of the relative motion speed between beacon 1 and reference element 2 provided by an embodiment of the present invention;

[0055] Figure 9 It is a schematic diagram of the estimated result of the relative motion speed between beacon 2 and reference element 2 provided by an embodiment of the present invention;

[0056] Figure 10 It is a schematic diagram of the estimated result of the relative motion speed between beacon 1 and reference element 3 provided by an embodiment of the present invention;

[0057] Figure 11 It is a schematic diagram of the estimated result of the relative motion speed between beacon 2 and reference element 3 provided by an embodiment of the present invention;

[0058] Figure 12An underwater target speed estimation device based on an underwater acoustic positioning system provided by an embodiment of the present invention;

[0059] Figure 13 A schematic structural diagram of an electronic device provided by an embodiment of the present invention. Specific embodiments

[0060] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0061] Currently, there are problems in existing underwater acoustic positioning such as difficult carrier tracking, cumulative symbol synchronization errors, and low information transmission reliability, resulting in low underwater acoustic positioning accuracy. Therefore, the estimation and compensation of Doppler are indispensable key links in an underwater acoustic positioning system. The Linear Frequency Modulation (LFM) signal is a commonly used detection signal for active sonar, which has strong autocorrelation and is insensitive to Doppler. Based on this, the present invention provides an underwater target speed estimation method, device, and equipment based on an underwater acoustic positioning system, which can accurately estimate the moving speed of an underwater dynamic target, provide Doppler information for real-time motion compensation in the underwater acoustic positioning system, and thus improve the underwater acoustic positioning accuracy.

[0062] To facilitate the understanding of this embodiment, first, a detailed introduction is given to an underwater target speed estimation method based on an underwater acoustic positioning system disclosed in the embodiments of the present invention. The underwater acoustic positioning system includes a signal processor, multiple underwater reference arrays, and multiple mobile acoustic beacons. In each working cycle, each mobile acoustic beacon polls and transmits at least two positioning acoustic signals, and each underwater reference array receives the positioning acoustic signals. This method is applied to the signal processor. Refer to Figure 1 The flowchart of an underwater target speed estimation method based on an underwater acoustic positioning system shown, and this method mainly includes the following steps S102 to step S110:

[0063] Step S102, based on the positioning acoustic signals transmitted by the target mobile acoustic beacon and the positioning acoustic signals received by the underwater reference array in the current working cycle, determine the time delay result and the signal transmission time interval in the current working cycle.

[0064] Among them, the positioning acoustic signal system is set to a bilinear frequency modulation (LFM) signal. As a large time-bandwidth product signal, the linear frequency modulation (LFM) signal has the prominent advantages that the matched filter is insensitive to the Doppler frequency shift of the echo signal and has good autocorrelation. The time delay result includes the time delay value of the target moving acoustic beacon relative to the underwater reference array element. The signal transmission time interval is also the time interval between two positioning acoustic signals sent by the target moving acoustic beacon, and the signal transmission time interval is equal to the sum of the duration of the guard interval between two positioning acoustic signals and the duration of the current working cycle (i.e., the LFM signal period).

[0065] In one example, the signal processor performs autocorrelation detection on the positioning acoustic signal sent by the target moving acoustic beacon and the positioning acoustic signal received by the underwater reference array element to obtain an autocorrelation sequence, searches for the two peaks corresponding to the double LFM signal according to the peak of the autocorrelation sequence to obtain the signal starting point, thereby obtaining the time delay between the target moving acoustic beacon and each underwater reference array element, and at the same time obtaining the time interval between the two peaks (i.e., the signal peak time interval), and takes the sum of it and the duration of the current working cycle as the signal transmission time interval.

[0066] Step S104, based on the time delay result and the signal transmission time interval in the current working cycle, determine the target Doppler prior information.

[0067] In one example, various methods can be used to roughly estimate the initial Doppler prior information. For example, according to the signal transmission time interval and the signal peak time interval (the signal peak time interval is the time interval between the peaks of any two positioning acoustic signals sent by the target moving acoustic beacon), the first Doppler prior information is roughly estimated by using the block estimation method; and, combining the time delay result in the current working cycle and the time delay result in the historical working cycle, the second Doppler prior information is roughly estimated; finally, the target Doppler prior information is determined by combining the initial Doppler prior information.

[0068] Step S106, use the target Doppler prior information and the signal transmission time interval to solve the phase difference integer ambiguity to determine the initial Doppler estimate value in the current working cycle.

[0069] In one example, the main board intercepted at the two peaks of the autocorrelation sequence is subjected to phase detection, and the phase difference integer ambiguity is solved by combining the target Doppler prior information and the signal transmission time interval. The Doppler estimate value corresponding to the integer cycle part of the phase is determined by using the phase difference integer ambiguity and the target Doppler prior information. At the same time, the Doppler estimate value corresponding to the non-periodic part of the phase is determined based on the signal transmission time interval, and the sum of the two corresponding Doppler estimate values is used as the initial Doppler estimate value.

[0070] Step S108: If it is determined that the initial Doppler estimate does not meet the preset decision feedback threshold according to the target Doppler prior information, the initial Doppler estimate is corrected using the target Doppler prior information to obtain the target Doppler estimate for the current working cycle.

[0071] In one example, if the absolute value of the difference between the target Doppler prior information and the initial Doppler estimate is greater than or equal to the decision feedback threshold, it can be determined that the initial Doppler estimate does not meet the preset decision feedback threshold. In this case, a new phase difference integer ambiguity is solved based on the target Doppler prior information, and then the Doppler correction value is determined. The initial Doppler estimate is corrected using the Doppler correction value to obtain the target Doppler estimate for the current working cycle.

[0072] Step S110: Estimate the underwater target speed estimation result for the current working cycle according to the target Doppler estimate.

[0073] Among them, the underwater target speed estimation result includes the movement speed of the target moving acoustic beacon relative to the underwater reference array element. In one example, the product of the target Doppler estimate and the sound speed is used as the underwater target speed estimation result for the current working cycle.

[0074] The underwater target speed estimation method based on the underwater acoustic positioning system provided by the embodiments of the present invention aims to utilize the acoustic signal interaction and positioning mechanism between the underwater reference array and the moving acoustic beacon to complete Doppler estimation and motion compensation in real time and with low complexity during the positioning process. By creating a dual-positioning acoustic signal system, rough Doppler estimation is performed, and the search space of the phase difference integer ambiguity is further compressed to achieve the fast and accurate solution of the accurate target Doppler estimate. The present invention not only has the advantages of low computational complexity, simple operation, and high accuracy, but also can accurately estimate the movement speed of underwater dynamic targets, provide Doppler information for motion compensation for the underwater acoustic positioning system in real time, thereby improving the underwater acoustic positioning accuracy.

[0075] Aiming at problems such as the increased time-delay estimation error and reduced positioning accuracy caused by the relative motion between the target and the reference array element in the traditional positioning system, the embodiment of the present invention proposes a method for low-complexity, real-time estimation of the motion speed and correction of Doppler based on the positioning system. In the embodiment of the present invention, the underwater acoustic positioning system includes a signal processor, multiple underwater reference array elements, and multiple mobile acoustic beacons. In each working cycle, each mobile acoustic beacon polls and transmits at least two positioning acoustic signals, and each underwater reference array element receives the positioning acoustic signals. Exemplarily, the positioning system mainly consists of 3 sets of underwater reference array elements, 1 set of signal processing units, and 2 sets of mobile acoustic beacons. The underwater reference array elements are statically suspended in the water or anchored to the bottom of the water, measuring the distance and azimuth information of the mobile acoustic beacons for target positioning. The positioning system supports diverse positioning signals and multiple transceiver positioning modes, and can perform three-dimensional dynamic positioning and tracking on multiple underwater targets simultaneously.

[0076] Based on the above positioning system, the embodiment of the present invention provides a specific implementation manner of a method for estimating the speed of an underwater target based on an underwater acoustic positioning system. Refer to Figure 2 the algorithm flow block diagram of a method for estimating the speed of an underwater target based on an underwater acoustic positioning system as shown, including steps S202 to S212:

[0077] Step S202, signal detection and correlation operation of the received signal:

[0078] Signal detection and correlation operation of the received signal: In the detection intervals set in two time periods of (0~T1) and (T~2*T1), the positioning acoustic signals received by the underwater reference array element perform time-domain waveform detection of the positioning signals of two beacons, and the positioning acoustic signals sent by the target mobile acoustic beacon perform correlation operation to obtain a correlation sequence , and estimate the time-delay, amplitude, and phase parameters of the positioning acoustic signal.

[0079] Specifically: Taking a linear frequency modulation rectangular pulse sample signal as an example, the expression of the positioning acoustic signal sent by the target mobile acoustic beacon is:

[0080] ;

[0081] where is the carrier frequency, is the signal period, is the frequency change rate, is the rectangular function, and assuming the guard interval between the two signals is set to . Refer to Figure 3Schematic diagram of a mobile acoustic beacon transmitting a positioning acoustic signal. The underwater reference elements 1# to 3# receive signals. If the polling period is T1, taking a double-pulse as an example, within the detection intervals set by the signal processor in two time periods (0 to T1) and (T to 2*T1), time-domain waveform detection and correlation peak detection are respectively performed on the positioning acoustic signals received by the underwater reference element channels 1 to 3.

[0082] In one implementation, during the selected detection period, the signal processor processes the positioning acoustic signal received by the underwater reference elements and the single LFM sample signal transmitted by the target mobile acoustic beacon to perform autocorrelation. Under the condition that the noise is uncorrelated with the signal, the correlation sequence can be expressed as:

[0083] ;

[0084] where is the time delay, is the sequence of the autocorrelation part, is the sequence of the cross-correlation part. According to the amplitude of the sequence of the autocorrelation part, the two peaks corresponding to the double LFM signal are found to obtain the signal starting point, thereby obtaining the time delays t11, t21, and t31 between the 1# mobile acoustic beacon and the three underwater reference elements, and the time delays t12, t22, and t32 between the 2# mobile acoustic beacon and the three underwater reference elements. At the same time, the time interval between the two peaks (i.e., the signal peak time interval) is . According to the duration of the current working cycle (i.e., the single LFM signal period) , the prior information of the protection interval duration between the double signals , let the signal transmission time interval .

[0085] Step S204, Coarse estimation of Doppler frequency offset:

[0086] During the selected detection period, according to the correlation sequence , the two correlation peaks corresponding to the double LFM signal are found by the amplitude, and the time interval between the two correlation peaks (i.e., the signal peak time interval) is . According to the signal peak time interval and the prior information of the signal transmission time interval , the coarse estimated value of the Doppler frequency offset factor, that is, the first Doppler prior information , is obtained by using the block estimation method. At the same time, combined with the time delay results of the historical working cycles, the distance changes of each mobile acoustic beacon relative to each underwater reference element and the corresponding motion speeds are obtained, and the second Doppler prior information is . is the moving speed of the mobile acoustic beacon relative to the underwater reference array element, and \(c\) is the speed of sound. Observe and judge and Whether they are consistent, the two will be used as the target Doppler prior information to determine whether there is phase ambiguity.

[0087] In the specific implementation, the following steps 1.1 to 1.3 can be included:

[0088] Step 1.1: Determine the first Doppler prior information based on the ratio between the signal peak time interval and the signal emission time interval. Specifically, the first Doppler prior information is determined according to the following formula :

[0089] ;

[0090] wherein, \(T_{peak}\) is the signal peak time interval, \(T_{emit}\) is the signal emission time interval.

[0091] Step 1.2: Based on the time delay result in the current working cycle and the time delay result in the historical working cycle, determine the distance change between the target mobile acoustic beacon and the underwater reference array element in the current working cycle, so as to determine the initial movement speed between the target mobile acoustic beacon and the underwater reference array element in the current working cycle, and determine the second Doppler prior information based on the initial movement speed.

[0092] Specifically, combining the time delay results of the historical working cycle, the distance change (m) of the mobile acoustic beacon relative to each underwater reference array element can be obtained. Taking the mobile acoustic beacon 1 and the underwater reference array element 1# as an example, the distance change (m) of the mobile acoustic beacon 1# relative to the underwater reference array element 1# in the current working cycle is , where \(c\) is the speed of sound (m / s), so the movement speed of the mobile acoustic beacon 1# relative to the underwater reference array element 1# in the current working cycle , and the Doppler factor can be obtained as , and the same applies to other underwater reference array elements.

[0093] Step 1.3: Determine the target Doppler prior information according to the first Doppler prior information and the second Doppler prior information. In one example, if the first Doppler prior information and the second Doppler prior information are consistent, the target Doppler prior information can be directly obtained: ; if the first Doppler prior information and the second Doppler prior information If they are inconsistent, one of them can be selected as the target Doppler prior information , or the two can be fused (such as weighted averaging) to obtain the target Doppler prior information .

[0094] Step S206, phase ambiguity judgment:

[0095] Intercept the main lobes at the peaks of any two positioning sound signals sent by the target moving sound beacon for phase detection to obtain the first correlation peak phase and the second correlation peak phase . Take the difference between the first correlation peak phase and the second correlation peak phase as the correlation peak main lobe phase difference:

[0096] ;

[0097] Among them, is the correlation peak main lobe phase difference, is the phase integer ambiguity, is the non-integer period part of the phase, is the first correlation peak phase, is the second correlation peak phase, is the frequency, is the change value of the time interval between two positioning sound signals. According to the judgment result of whether there is phase ambiguity in step S204, if not, directly output the initial Doppler estimate value ; if so, execute step S208.

[0098] Step S208, phase integer ambiguity calculation:

[0099] Based on the target Doppler prior information , calculate the quotient obtained by dividing the absolute value of the target Doppler prior information by . Based on this quotient, solve the phase integer ambiguity and the Doppler estimate value corresponding to the phase integer period part to obtain the initial Doppler estimate value . Specifically, the following steps 2.1 to 2.3 can be referred to:

[0100] Step 2.1, according to the correlation peak main lobe phase difference and the signal emission time interval, split the initial Doppler estimate value into the phase integer period part and the non-integer period part of the phase:

[0101] ;

[0102] Among them, is the initial Doppler estimate value, is the phase difference of the main lobe of the correlation peak, , is the frequency, is the signal emission time interval, is the Doppler estimate value corresponding to the integer cycle part of the phase, is the Doppler estimate value corresponding to the non-integer cycle part of the phase.

[0103] Step 2.2: Determine the Doppler estimate value corresponding to the non-integer cycle part of the phase; and, solve the phase difference integer ambiguity based on the target Doppler prior information to determine the Doppler estimate value corresponding to the integer cycle part of the phase using the phase difference integer ambiguity.

[0104] Based on the formula provided in Step 2.1, it can be known that: ; Since , are all known quantities, the Doppler estimate value corresponding to the non-integer cycle part of the phase can be directly calculated.

[0105] Based on the formula provided in Step 2.1, it can be known that: ; where is the phase difference integer ambiguity to be solved, and the Doppler estimate value corresponding to the integer cycle part of the phase cannot be directly calculated. On this basis, the phase difference integer ambiguity is determined according to the following formula:

[0106] , ;

[0107] where, is the phase difference integer ambiguity, is an intermediate parameter, is the target Doppler prior information, is the frequency, is the signal emission time interval, [] represents rounding down to zero, is rounding down;

[0108] The Doppler estimate value corresponding to the integer cycle part of the phase is determined according to the following formula:

[0109] ;

[0110] where, is the Doppler estimate value corresponding to the integer cycle part of the phase, is the target Doppler prior information, is the Doppler estimate value corresponding to the non-integer cycle part of the phase.

[0111] Step 2.3, Doppler estimation value corresponding to the non-integer cycle part of the phase and the Doppler estimation value corresponding to the integer cycle part of the phase The sum value is used as the initial Doppler estimation value . Specifically: .

[0112] Step S210, decision feedback to correct the integer ambiguity and Doppler estimation value:

[0113] Further considering that when the true value of the phase difference between two correlation peaks approaches the periodic boundary of its value range, affected by measurement errors, the integer ambiguity of the phase and its corresponding Doppler estimation value There are jump situations, which makes the estimation error larger. To solve this problem, the embodiment of the present invention adds a decision feedback step, see steps 3.1 to 3.4 below:

[0114] Step 3.1, if the difference between the target Doppler prior information and the initial Doppler estimation value is greater than the preset decision feedback threshold, it is determined that the initial Doppler estimation value does not meet the decision feedback threshold.

[0115] According to the initial Doppler estimation value Compared with the target Doppler prior information Calculate the difference between the two, denoted as the estimation error , set the decision feedback threshold , if it satisfies , then Is used as the target Doppler estimation value; if it satisfies , then continue to correct , the correction process can refer to the subsequent steps 3.2 to 3.4.

[0116] Step 3.2, according to the difference between the target Doppler prior information and the initial Doppler estimation value, correct the integer ambiguity of the phase difference to obtain a new integer ambiguity of the phase difference. Specifically, the new integer ambiguity of the phase difference can be determined according to the following formula:

[0117] , ;

[0118] Among them, Is the new integer ambiguity of the phase difference, Is an intermediate parameter, Is the target Doppler prior information And the initial Doppler estimation value The difference between, Is the frequency, is the signal emission time interval, and [] represents rounding down to zero. is rounding down.

[0119] Step 3.3: Determine the Doppler factor correction value based on the new phase difference integer ambiguity. Specifically, the Doppler factor correction value can be determined according to the following formula:

[0120] ;

[0121] where is the Doppler factor correction value, is the target Doppler prior information, is is an intermediate parameter, is the frequency, is the signal emission time interval.

[0122] Step 3.4: Use the sum of the initial Doppler estimate value and the Doppler factor correction value as the target Doppler estimate value for the current working cycle. Specifically, the corrected initial Doppler estimate value is: . The difference between the once-corrected initial Doppler estimate value and the target Doppler prior information If the difference is still greater than the threshold , then repeat the aforementioned Steps 3.1 to 3.4. If it is less than the threshold , then use it as the target Doppler estimate value.

[0123] Step S212: Positioning motion compensation:

[0124] In one example, multiply the target Doppler estimate value by the speed of sound to obtain the underwater target speed estimation result for the current working cycle: ; where is the underwater target speed estimation result, that is, the relative motion speed between the moving acoustic beacon and the underwater reference element, is the target Doppler estimate value, is the speed of sound.

[0125] Further, according to the underwater target speed estimation result, correct the time delay result for the current working cycle. Based on the corrected time delay result, perform positioning calculation through the geometric spherical intersection principle to obtain the real-time positioning result of the target moving acoustic beacon for the current working cycle. Specifically, according to the underwater target speed estimation result, correct the time delay result between each moving acoustic beacon and each underwater reference element to . Based on the corrected time delays between the moving acoustic beacon and three underwater reference elements and the known coordinates of the transducers 1#~3# of the underwater reference elements , positioning and calculation are performed according to the principle of geometric spherical intersection. Taking the 1# mobile acoustic beacon as an example, the real-time positioning result of the 1# mobile acoustic beacon is calculated according to the following formula :

[0126] ;

[0127] ;

[0128] ;

[0129] And the corrected time delay result and the real-time positioning result are uploaded to the PC display and control software.

[0130] In the embodiment of the present invention, aiming at the problems of increased time delay estimation error and reduced positioning accuracy caused by the relative movement between the mobile acoustic beacon and the underwater reference array element in the positioning system, it is intended to use the acoustic signal intercommunication and positioning mechanism between the positioning array and the beacon unit to complete Doppler estimation and motion compensation in real time and with low complexity during the positioning process. By creating a dual-LFM positioning signal system, rough Doppler estimation is performed using historical positioning time delay and correlation sequence block estimation information, and further compressing the phase ambiguity search space to achieve fast and accurate solution of the precise Doppler factor. The embodiment of the present invention has low computational complexity, simple operation, and high accuracy. The lake test results show that this method can accurately estimate the motion speed of underwater dynamic targets, provide Doppler information for the underwater acoustic positioning system in real time for motion compensation, and improve the positioning accuracy.

[0131] Furthermore, the embodiment of the present invention also provides an application example of a method for estimating the speed of an underwater target based on an underwater acoustic positioning system.

[0132] The underwater acoustic positioning test in the embodiment of the present invention is carried out at the Xin'anjiang test site in Qiandao Lake. The average water depth of the test water area is about 40m - 50m, as Figure 4Schematic diagram of a lake test scenario setup. First, build a bottom reference transceiver unit support to ensure that the transceiver unit is more than 1.5 m above the bottom. Lower the bottom reference transceiver unit by cable winching. Place the reference node transducer on the bottom. Place the 1# element at the bottom of the southwest corner of the pontoon, the 2# element at the bottom of the northwest corner of the pontoon, and the 3# element at the bottom of the middle position on the east side of the pontoon. Pontoon specifications: about 45 m long from north to south and about 22 m wide. During the placement process, through self-test array mode positioning, the distance between the bottom transducer 1# and 2# is 48.165 m, the distance between 1# and 3# is 31.68 m, the distance between 2# and 3# is 35.09 m, and the placement depth is 45 m, which is consistent with the actual placement distance and placement formation. Then, fix 2 beacon transceiver units at both ends of a 3.76 m long glass steel pipe, and tie ropes at both ends of the pipe for lowering the overall structure. At the center of the pontoon, control the steel pipe with double ropes. After lowering it to a certain depth, slowly move the ropes horizontally / vertically to make the steel pipe move. The test scenario is set up as shown in the following figure. During the test process, record the positioning results of beacon 1# and beacon 2#, count the positioning results during the movement, and calculate the mean and variance of the distance between the two, which are used as the criteria for positioning accuracy. The system operating frequency band is 20 kHz to 30 kHz, the operating period T1 is 1 s, and a double LFM signal is transmitted as the positioning signal. The period of one LFM signal is 5 ms, and the interval between the two LFM signals is 100 ms. A total of 500 cycles are counted to observe the positioning results and the changes in the movement speeds of beacon 1# and beacon 2#.

[0133] Taking the double LFM positioning signals polled and transmitted by beacon 1 and beacon 2 received by reference element 1 in the third cycle as an example, the received signals and the LFM sample signals After correlation, the correlation results in the following figure can be obtained. Calculate the interval between the two correlation peaks and their phase difference. According to the LFM signal period and the protection interval duration between the two signals and other prior information, the relative motion speed estimation results of beacon 1 and beacon 2 with respect to reference element 1 can be obtained. See Figure 5 Schematic diagram of the correlation results of the double LFM positioning signals polled and transmitted by beacon 1 and beacon 2 received by reference element 1 shown

[0134] To verify the accuracy of the speed estimation method in the embodiment of the present invention, compare the speed estimation results of this method with the following two speed estimation results. The first is to obtain the motion speed between the two based on the positioning results of each beacon and the reference element by the position vector, and the second is to combine the time delay results of historical cycles to obtain the distance change and speed of the beacon relative to each reference element in this cycle. The three speed estimation results are as follows Figure 6 、 Figure 7 shown Figure 6It is a schematic diagram of the estimated relative motion speed of beacon 1 and reference element 1. Figure 7 It is a schematic diagram of the estimated relative motion speed of beacon 2 and reference element 1. Similarly, the estimated relative motion speeds of beacon 1 and beacon 2 with respect to reference element 2 can be obtained. Refer to Figure 8 the schematic diagram of the estimated relative motion speed of beacon 1 and reference element 2 as shown. Figure 9 the schematic diagram of the estimated relative motion speed of beacon 2 and reference element 2 as shown. Similarly, the estimated relative motion speeds of beacon 1 and beacon 2 with respect to reference element 3 can be obtained. Refer to Figure 10 the schematic diagram of the estimated relative motion speed of beacon 1 and reference element 3 as shown. Figure 11 the schematic diagram of the estimated relative motion speed of beacon 2 and reference element 3 as shown.

[0135] From the test results, it can be seen that the speed estimation results of the embodiments of the present invention are consistent with the estimation results of the other two methods, and the estimation error is about 0.02 m / s. According to the measured Doppler values above, the positioning time delay is compensated. After observing the results of the distance between beacon 1 and beacon 2 after compensation, it can be obtained that after Doppler compensation, the distance between beacon 1 and beacon 2 increases from 3.71 m to 3.74 m, which is closer to the actual value of 3.76 m, and the positioning error decreases from 5 cm to 2 cm, as detailed below.

[0136] The change in the distance between the two beacons measured from the originally uploaded positioning data is:

[0137]

[0138] According to the measured motion speed, the Doppler correction is performed on the uploaded time delay. The results are as follows:

[0139]

[0140] According to the motion speed measured by the correlation peak phase, the Doppler correction is performed on the uploaded time delay:

[0141]

[0142] In summary, the embodiments of the present invention utilize the acoustic signal communication and positioning mechanism between the positioning array and the beacon unit to complete Doppler estimation and motion compensation in real time with low complexity during the positioning process, and solve problems such as the increase in time delay estimation error and the decrease in positioning accuracy caused by the relative motion between the target and the reference array element. By creating a dual-LFM positioning signal system, rough Doppler estimation is performed using historical positioning time delay and correlation sequence block estimation information, and the phase ambiguity search space is further compressed to achieve fast and accurate solution of the precise Doppler factor. This method has low computational complexity, simple operation, and high accuracy. The results of lake tests show that this method can accurately estimate the motion speed of underwater dynamic targets. The speed estimation results of the present invention are consistent with the motion speed obtained from the position vector of the positioning result and the distance change and speed method estimation results of the current period obtained by combining historical periodic time delays, and the estimation error is about 0.02 m / s. According to the measured Doppler value above, the positioning time delay is compensated, and it can be obtained that the positioning error after Doppler compensation is reduced from 5 cm to 2 cm. The test proves that this method can provide Doppler information for the underwater acoustic positioning system in real time, and the positioning accuracy can be improved after motion compensation.

[0143] Based on the foregoing embodiments, an embodiment of the present invention provides an underwater target speed estimation device based on an underwater acoustic positioning system. The underwater acoustic positioning system includes a signal processor, a plurality of underwater reference array elements, and a plurality of mobile acoustic beacons. Each mobile acoustic beacon polls and transmits at least two positioning acoustic signals in each working cycle, and each underwater reference array element receives the positioning acoustic signals. This device is applied to the signal processor. Refer to Figure 12 An underwater target speed estimation device based on an underwater acoustic positioning system as shown, which mainly includes the following parts:

[0144] A signal detection module 1202, configured to determine the time delay result and the signal transmission time interval in the current working cycle based on the positioning acoustic signals transmitted by the target mobile acoustic beacon and received by the underwater reference array element in the current working cycle; wherein, the time delay result includes the time delay value of the target mobile acoustic beacon relative to the underwater reference array element.

[0145] A prior information determination module 1204, configured to determine the target Doppler prior information based on the time delay result and the signal transmission time interval in the current working cycle.

[0146] A Doppler estimated value determination module 1206, configured to solve the phase difference integer ambiguity using the target Doppler prior information and the signal transmission time interval to determine the initial Doppler estimated value in the current working cycle.

[0147] A Doppler estimation value correction module 1208, configured to correct an initial Doppler estimation value by using target Doppler prior information to obtain a target Doppler estimation value in the current working period if it is determined according to the target Doppler prior information that the initial Doppler estimation value does not meet a preset decision feedback threshold;

[0148] A speed estimation module 1210, configured to estimate an underwater target speed estimation result in the current working period according to the target Doppler estimation value, where the underwater target speed estimation result includes a moving speed of a target moving acoustic beacon relative to an underwater reference array element.

[0149] The underwater target speed estimation device based on an underwater acoustic positioning system provided by an embodiment of the present invention aims to utilize the acoustic signal intercommunication and positioning mechanism between an underwater reference array and a moving acoustic beacon, complete Doppler estimation and motion compensation in real time and with low complexity during the positioning process, create a dual-positioning acoustic signal system, perform rough Doppler estimation, and further compress the search space of the phase difference cycle ambiguity to achieve fast and accurate solution of an accurate target Doppler estimation value. The present invention not only has advantages such as low computational complexity, simple operation, and high accuracy, but also can accurately estimate the moving speed of an underwater dynamic target, provide Doppler information for motion compensation for the underwater acoustic positioning system in real time, thereby improving the underwater acoustic positioning accuracy.

[0150] In an implementation manner, the signal transmission time interval is a sum value between a guard interval duration between two positioning acoustic signals and a duration of the current working period; the prior information determination module 1204 is specifically configured to:

[0151] Determine first Doppler prior information based on a ratio between a signal peak time interval and the signal transmission time interval, where the signal peak time interval is a time interval between peaks of any two positioning acoustic signals sent by a target moving acoustic beacon;

[0152] Determine a distance change between a target moving acoustic beacon and an underwater reference array element in the current working period based on a time delay result in the current working period and a time delay result in a historical working period, so as to determine an initial moving speed between the target moving acoustic beacon and the underwater reference array element in the current working period, and determine second Doppler prior information based on the initial moving speed;

[0153] Determine target Doppler prior information according to the first Doppler prior information and the second Doppler prior information.

[0154] In an implementation manner, the Doppler estimation value determination module 1206 is specifically configured to:

[0155] Intercept the main lobes at the peaks of any two positioning sound signals sent by the target moving sound beacon for phase detection to obtain the first correlation peak phase and the second correlation peak phase, and take the difference between the first correlation peak phase and the second correlation peak phase as the correlation peak main lobe phase difference;

[0156] According to the correlation peak main lobe phase difference and the signal emission time interval, split the initial Doppler estimate into a phase integer cycle part and a phase non-integer cycle part;

[0157] Determine the Doppler estimate corresponding to the phase non-integer cycle part; and, solve the phase difference integer ambiguity based on the target Doppler prior information to determine the Doppler estimate corresponding to the phase integer cycle part using the phase difference integer ambiguity;

[0158] The sum of the Doppler estimate corresponding to the phase non-integer cycle part and the Doppler estimate corresponding to the phase integer cycle part is used as the initial Doppler estimate.

[0159] In one implementation manner, the Doppler estimate determination module 1206 is specifically configured to:

[0160] Determine the phase difference integer ambiguity according to the following formula:

[0161] , ;

[0162] where, is the phase difference integer ambiguity, is an intermediate parameter, is the target Doppler prior information, is the frequency, is the signal emission time interval, [ ] represents rounding towards zero, is rounding down;

[0163] Determine the Doppler estimate corresponding to the phase integer cycle part according to the following formula:

[0164] ;

[0165] where, is the Doppler estimate corresponding to the phase integer cycle part, is the target Doppler prior information, is the Doppler estimate corresponding to the phase non-integer cycle part.

[0166] In one implementation manner, the Doppler estimate correction module 1208 is specifically configured to:

[0167] If the difference between the target Doppler prior information and the initial Doppler estimate is greater than a preset decision feedback threshold, it is determined that the initial Doppler estimate does not meet the decision feedback threshold.

[0168] In one embodiment, the Doppler estimate correction module 1208 is specifically configured to:

[0169] Correct the phase difference cycle ambiguity according to the difference between the target Doppler prior information and the initial Doppler estimate to obtain a new phase difference cycle ambiguity;

[0170] Determine the Doppler factor correction value based on the new phase difference cycle ambiguity;

[0171] Use the sum of the initial Doppler estimate and the Doppler factor correction value as the target Doppler estimate in the current working cycle.

[0172] In one embodiment, it further includes a positioning module, which is used to:

[0173] Correct the time delay result in the current working cycle according to the underwater target speed estimation result;

[0174] Based on the corrected time delay result, perform positioning calculation through the geometric spherical intersection principle to obtain the real-time positioning result of the target moving acoustic beacon in the current working cycle.

[0175] The device provided by the embodiment of the present invention has the same implementation principle and the same technical effects as those of the foregoing method embodiment. For the sake of brief description, for the parts not mentioned in the device embodiment, reference may be made to the corresponding content in the foregoing method embodiment.

[0176] The embodiment of the present invention provides an electronic device. Specifically, the electronic device includes a processor and a storage device; a computer program is stored on the storage device, and the computer program executes the method described in any one of the above embodiments when being run by the processor.

[0177] Figure 13 FIG. is a schematic structural diagram of an electronic device provided by an embodiment of the present invention. The electronic device 100 includes: a processor 130, a memory 131, a bus 132, and a communication interface 133. The processor 130, the communication interface 133, and the memory 131 are connected through the bus 132; the processor 130 is used to execute an executable module stored in the memory 131, such as a computer program.

[0178] Among them, the memory 131 may include a high-speed random access memory (RAM, Random Access Memory), and may also include a non-volatile memory, such as at least one disk memory. Through at least one communication interface 133 (which can be wired or wireless), a communication connection is realized between this system network element and at least one other network element, and the Internet, wide area network, local area network, metropolitan area network, etc. can be used.

[0179] The bus 132 can be an ISA bus, a PCI bus, an EISA bus, or the like. The bus can be divided into an address bus, a data bus, a control bus, etc. For the sake of convenience of representation, Figure 13 it is only represented by a single bidirectional arrow in the figure, but it does not mean that there is only one bus or one type of bus.

[0180] Among them, the memory 131 is used to store a program. After receiving an execution instruction, the processor 130 executes the program. The method executed by the device defined by the flow process disclosed in any of the foregoing embodiments of the present invention can be applied to the processor 130 or implemented by the processor 130.

[0181] The processor 130 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the integrated logic circuit in the hardware of the processor 130 or the instructions in the form of software. The above-mentioned processor 130 can be a general-purpose processor, including a central processing unit (CPU for short), a network processor (NP for short), etc.; it can also be a digital signal processor (DSP for short), an application specific integrated circuit (ASIC for short), a field-programmable gate array (FPGA for short), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. It can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present invention. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in combination with the embodiments of the present invention can be directly embodied as being completed by the hardware decoding processor, or completed by a combination of the hardware and software modules in the decoding processor. The software module can be located in a mature storage medium in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. This storage medium is located in the memory 131, and the processor 130 reads the information in the memory 131 and combines its hardware to complete the steps of the above method.

[0182] The computer program product of the readable storage medium provided by the embodiments of the present invention includes a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the method described in the foregoing method embodiments. For the specific implementation, reference can be made to the foregoing method embodiments, which will not be elaborated here.

[0183] If the above-described functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The foregoing storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs.

[0184] Finally, it should be noted that the above-described embodiments are only specific embodiments of the present invention, used to illustrate the technical solutions of the present invention, rather than limiting them. The protection scope of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that any technician familiar with the technical field of the present invention can still modify the technical solutions described in the foregoing embodiments, or easily conceive of changes, or make equivalent replacements for some of the technical features; and these modifications, changes, or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. An underwater target speed estimation method based on an underwater acoustic positioning system, characterized in that, The underwater acoustic positioning system includes a signal processor, multiple underwater reference arrays, and multiple mobile acoustic beacons. In each working cycle, each of the mobile acoustic beacons polls and transmits at least two positioning acoustic signals, and each of the underwater reference arrays receives the positioning acoustic signals. The method is applied to the signal processor and includes: Based on the positioning acoustic signals transmitted by the target mobile acoustic beacon and the positioning acoustic signals received by the underwater reference array in the current working cycle, determine the time delay result and the signal transmission time interval in the current working cycle; wherein, the time delay result includes the time delay value of the target mobile acoustic beacon relative to the underwater reference array. Based on the time delay result and the signal transmission time interval in the current working cycle, determine the target Doppler prior information. Use the target Doppler prior information and the signal transmission time interval to solve the phase difference integer ambiguity to determine the initial Doppler estimate value in the current working cycle. If it is determined according to the target Doppler prior information that the initial Doppler estimate value does not meet the preset decision feedback threshold, then use the target Doppler prior information to correct the initial Doppler estimate value to obtain the target Doppler estimate value in the current working cycle. Estimate the underwater target speed estimate result in the current working cycle according to the target Doppler estimate value, and the underwater target speed estimate result includes the movement speed of the target mobile acoustic beacon relative to the underwater reference array.

2. The underwater target speed estimation method based on an underwater acoustic positioning system according to claim 1, wherein The signal transmission time interval is the sum value between the protection interval duration between two positioning acoustic signals and the duration of the current working cycle. Based on the time delay result and the signal transmission time interval in the current working cycle, determining the target Doppler prior information includes: Based on the ratio between the signal peak time interval and the signal transmission time interval, determine the first Doppler prior information, and the signal peak time interval is the time interval between the peaks of any two positioning acoustic signals transmitted by the target mobile acoustic beacon. Based on the time delay result in the current working cycle and the time delay result in the historical working cycle, determine the distance change between the target mobile acoustic beacon and the underwater reference array in the current working cycle to determine the initial movement speed of the target mobile acoustic beacon relative to the underwater reference array in the current working cycle, and determine the second Doppler prior information based on the initial movement speed. According to the first Doppler prior information and the second Doppler prior information, determine the target Doppler prior information.

3. The underwater target speed estimation method based on an underwater acoustic positioning system according to claim 1, characterized in that Using the target Doppler prior information and the signal transmission time interval to solve the phase difference integer ambiguity to determine the initial Doppler estimate value in the current working cycle includes: Intercept the main lobes at the peaks of any two positioning acoustic signals transmitted by the target mobile acoustic beacon for phase detection to obtain the first correlation peak phase and the second correlation peak phase, and use the difference between the first correlation peak phase and the second correlation peak phase as the correlation peak main lobe phase difference. Split the initial Doppler estimate into an integer cycle part and a non-integer cycle part of the phase according to the main lobe phase difference of the relevant peak and the signal emission time interval; Determine the Doppler estimate corresponding to the non-integer cycle part of the phase; and solve the integer ambiguity of the phase difference based on the prior information of the target Doppler, so as to determine the Doppler estimate corresponding to the integer cycle part of the phase by using the integer ambiguity of the phase difference; The sum of the Doppler estimate corresponding to the non-integer cycle part of the phase and the Doppler estimate corresponding to the integer cycle part of the phase is used as the initial Doppler estimate.

4. The underwater target speed estimation method based on an underwater acoustic positioning system according to claim 3, characterized in that Solving the integer ambiguity of the phase difference based on the prior information of the target Doppler, so as to determine the Doppler estimate corresponding to the integer cycle part of the phase by using the integer ambiguity of the phase difference, includes: Determine the integer ambiguity of the phase difference according to the following formula: ， ； Among them, is the phase difference cycle ambiguity, is an intermediate parameter, is the target Doppler prior information, is the frequency, is the signal emission time interval, and [] represents rounding towards zero, is rounding down; Determine the Doppler estimate corresponding to the integer cycle part of the phase according to the following formula: ； wherein, is the Doppler estimate corresponding to the integer cycle part of the phase, is the target Doppler prior information, is the Doppler estimate corresponding to the non-integer cycle part of the phase.

5. The underwater target speed estimation method based on an underwater acoustic positioning system according to claim 1, characterized in that Before it is determined that the initial Doppler estimate does not meet the preset decision feedback threshold according to the prior information of the target Doppler, the method further includes: If the difference between the prior information of the target Doppler and the initial Doppler estimate is greater than the preset decision feedback threshold, it is determined that the initial Doppler estimate does not meet the decision feedback threshold.

6. The underwater target speed estimation method based on an underwater acoustic positioning system according to claim 1, wherein Using the prior information of the target Doppler to correct the initial Doppler estimate to obtain the target Doppler estimate in the current working cycle, includes: Correct the integer ambiguity of the phase difference according to the difference between the prior information of the target Doppler and the initial Doppler estimate to obtain a new integer ambiguity of the phase difference; Determine the Doppler factor correction value based on the new integer ambiguity of the phase difference; The sum of the initial Doppler estimate and the Doppler factor correction value is used as the target Doppler estimate in the current working cycle.

7. The underwater target speed estimation method based on an underwater acoustic positioning system according to claim 1, wherein After estimating the underwater target speed estimation result in the current working cycle according to the target Doppler estimate, the method further includes: Correct the time delay result in the current working cycle according to the underwater target speed estimation result; Based on the corrected time delay result, perform positioning calculation through the geometric spherical intersection principle to obtain the real-time positioning result of the target moving acoustic beacon in the current working cycle.

8. An underwater target speed estimation device based on an underwater acoustic positioning system, characterized in that, The underwater acoustic positioning system includes a signal processor, a plurality of underwater reference arrays and a plurality of moving acoustic beacons. In each working cycle, each moving acoustic beacon polls and transmits at least two positioning acoustic signals, and each underwater reference array receives the positioning acoustic signals. The device is applied to the signal processor, and the device includes: A signal detection module, configured to determine the time delay result and the signal emission time interval in the current working cycle based on the positioning acoustic signal sent by the target moving acoustic beacon and the positioning acoustic signal received by the underwater reference array in the current working cycle; wherein, the time delay result includes the time delay value of the target moving acoustic beacon relative to the underwater reference array; A priori information determination module, configured to determine target Doppler a priori information based on the time delay result and the signal transmission time interval in the current working period; Doppler estimate determination module, configured to solve the phase difference cycle ambiguity by using the target Doppler a priori information and the signal transmission time interval, so as to determine the initial Doppler estimate in the current working period; Doppler estimate correction module, configured to, if it is determined according to the target Doppler a priori information that the initial Doppler estimate does not meet a preset decision feedback threshold, correct the initial Doppler estimate by using the target Doppler a priori information to obtain the target Doppler estimate in the current working period; Velocity estimation module, configured to estimate the underwater target velocity estimation result in the current working period according to the target Doppler estimate, where the underwater target velocity estimation result includes the motion velocity of the target moving acoustic beacon relative to the underwater reference array element.

9. An electronic device, characterized in that, It includes a processor and a memory, the memory stores computer executable instructions that can be executed by the processor, and the processor executes the computer executable instructions to implement the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer executable instructions, and when the computer executable instructions are called and executed by a processor, the computer executable instructions cause the processor to implement the method according to any one of claims 1 to 7.

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