Underwater object positioning method and system

Abstract

The embodiment of the invention provides an underwater object positioning method and system, and the method comprises the steps: determining a first coordinate of an underwater object according to a signal received by a sensor node; determining a target sensor node of an area where the first coordinate is located according to the first coordinate; emitting an optical signal through the target sensor node; and determining a target coordinate of the underwater object according to the optical signal received by the underwater object. The objective of the invention is to improve underwater object positioning precision and reduce positioning cost.

Description

Technical Field

[0001] This invention relates to the field of underwater positioning technology, and specifically to a method and system for locating underwater objects. Background Technology

[0002] In the current exploration and utilization of rivers, lakes, and seas, it is necessary to construct underwater networks to ensure the safety of operations such as energy extraction, marine emergency response, network inspection and maintenance, and object salvage. Due to factors such as the wave-like nature of water and the shielding of electromagnetic signals, it is crucial to design a method for precise object positioning using information from underwater anchor nodes.

[0003] Currently, the main methods for locating underwater objects include sensor network positioning, underwater acoustic positioning, and wireless optical positioning. However, using any one of these three methods individually can result in insufficient positioning accuracy and complex positioning algorithms. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide a method and system for locating underwater objects. The aim is to improve the accuracy of underwater object positioning while reducing positioning costs.

[0005] The first aspect of this invention provides a method for locating underwater objects, the method comprising:

[0006] The first coordinates of the underwater object are determined based on the signals received by the sensor nodes;

[0007] Based on the first coordinates, determine the target sensor node in the area where the first coordinates are located;

[0008] The target sensor node emits a light signal;

[0009] The target coordinates of the underwater object are determined based on the optical signal received by the underwater object.

[0010] Optionally, determining the target sensor node in the area where the first coordinates are located based on the first coordinates includes:

[0011] Based on the first coordinate, determine the distance between each sensor node and the first coordinate;

[0012] Based on the distance, a preset number of sensor nodes that are closest to the first coordinate are determined as target sensor nodes.

[0013] Optionally, determining the target sensor node in the area where the first coordinates are located based on the first coordinates includes:

[0014] Based on the first coordinates and the preset length, a target area is determined with the first coordinates as the center and the preset length as the radius.

[0015] Determine the number of sensor nodes within the target area;

[0016] If the number is less than or equal to a preset number, all sensor nodes within the target area are identified as target sensor nodes.

[0017] If the number is greater than the preset number, determine the distance between each sensor node in the target area and the first coordinate.

[0018] Based on the distance, the sensor nodes within the target area that are closest to the first coordinate are determined as target sensor nodes.

[0019] Optionally, emitting an optical signal through the target sensor node includes:

[0020] When the number is equal to or greater than the preset number, each target sensor node emits a corresponding beam of light signal;

[0021] If the number is less than the preset number, determine the number of target sensor nodes;

[0022] The target quantity is determined based on the preset quantity and the number of sensor nodes identified as targets;

[0023] The target number of light signals is emitted by the target sensor node closest to the first coordinate, and a corresponding beam of light is emitted by each of the other target sensor nodes.

[0024] Optionally, determining the target coordinates of the underwater object based on the optical signal received by the underwater object includes:

[0025] Based on the optical signal received by the underwater object, determine the received power of the optical signal channel path;

[0026] Based on the received power, determine the proportion of the received power to the total received power;

[0027] Based on the stated ratio, determine the weighting factor for the channel path;

[0028] The received power of the channel path is weighted and corrected by the weighting factor to obtain the target received power of the channel path;

[0029] Based on the target received power of each channel path, the first number of channel paths with the highest target received power are selected from all channel paths and determined as the target channel paths;

[0030] The target coordinates of the underwater object are determined based on the coordinates corresponding to the target channel path.

[0031] Optionally, determining the received power of the optical signal's channel path based on the optical signal received by the underwater object includes:

[0032] By processing the optical signal received by the underwater object, the channel impulse response vector of the optical signal is obtained;

[0033] The received power of the optical signal's channel path is determined based on the channel impulse response vector.

[0034] Optionally, the weighting factor of the channel path is determined according to the ratio, including:

[0035] The weighting factor of the channel path is obtained by substituting the proportion of the received power of the channel path to the total received power into the first algorithm for calculation. The first algorithm is as follows:

[0036]

[0037] Among them, h norm,i (i) represents the received power of the i-th channel path, w′ i This represents the weighting factor for the i-th channel path.

[0038] Optionally, the received power of the channel path is weighted and corrected using the weighting factor to obtain the target received power of the channel path, including:

[0039] The target received power of the channel path is obtained by substituting the weighting factor of the channel path and the total received power into the second algorithm for weighted correction calculation. The second algorithm is as follows:

[0040]

[0041] in, Let P be the target received power for the i-th channel path. r For the total received power, h LOS This represents the normalized amplitude of the line-of-sight link.

[0042] Optionally, determining the target coordinates of the underwater object based on the coordinates corresponding to the target channel path includes:

[0043] The Jacobian matrix and the deviation vector are calculated using the coordinates corresponding to the target channel path to obtain the values ​​of the Jacobian matrix and the deviation vector.

[0044] Based on the values ​​of the Jacobian matrix and the deviation vector, update the coordinates of the underwater object and the coordinates of the target channel path;

[0045] The number of iterative calculations to determine the coordinates of the underwater object;

[0046] If the number of iterations has not reached the preset number, return to the step: calculate the Jacobian matrix and the deviation vector using the coordinates corresponding to the target channel path to obtain the values ​​of the Jacobian matrix and the deviation vector;

[0047] When the number of iterations reaches the preset number, the coordinates of the underwater object at the last iteration are determined as the target coordinates of the underwater object.

[0048] A second aspect of the present invention provides a system for locating underwater objects, the system comprising:

[0049] The first coordinate determination module is used to determine the first coordinates of the underwater object based on the signals received by the sensor node.

[0050] The target sensor node determination module is used to determine the target sensor node in the area where the first coordinate is located based on the first coordinate.

[0051] An optical signal transmitting module is used to emit optical signals through the target sensor node;

[0052] The target coordinate determination module is used to determine the target coordinates of the underwater object based on the light signal received by the underwater object.

[0053] The underwater object positioning method provided by this invention has the following advantages:

[0054] This invention provides a method for locating underwater objects. First, a coarse location is performed on the underwater object based on signals received by sensor nodes to determine its current first coordinates. Then, a target sensor node in the area containing the first coordinate is identified. A light signal is emitted from the target sensor node in the area containing the first coordinate. Finally, a more accurate target coordinate is determined based on the light signal received by the underwater object from the target sensor node in the area containing the first coordinate. Thus, by introducing two positioning methods—first performing coarse location, and then using wireless optical positioning to more accurately locate the underwater object based on the coarse location—the accuracy of underwater object positioning can be effectively improved. Furthermore, this method, after determining the approximate location of the underwater object, activates a nearby laser for wireless optical positioning. Therefore, the frequency and duration of laser usage are significantly reduced, and the lifespan of the laser is increased. This improves the accuracy of underwater object positioning while also reducing underwater positioning costs. Attached Figure Description

[0055] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0056] Figure 1 This is a flowchart illustrating a method for locating underwater objects according to an embodiment of the present invention;

[0057] Figure 2 This is a schematic diagram illustrating the positioning of sensor nodes in an underwater object positioning method according to an embodiment of the present invention;

[0058] Figure 3 This is another flowchart illustrating a method for locating underwater objects according to an embodiment of the present invention;

[0059] Figure 4 This is a schematic diagram illustrating an underwater object positioning system according to an embodiment of the present invention. Detailed Implementation

[0060] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0061] refer to Figure 1 , Figure 1 This is a flowchart illustrating a method for locating underwater objects according to an embodiment of the present invention. Figure 1 As shown, the method includes:

[0062] Step S1: Determine the first coordinates of the underwater object based on the signal received by the sensor node.

[0063] In this embodiment, as Figure 2 As shown, Figure 2 This is a schematic diagram illustrating the sensor node positioning in an underwater object positioning method according to an embodiment of the present invention. A sensor network is deployed underwater to perform coarse positioning of underwater objects. At the same time, a laser is configured for each sensor node in the sensor network to achieve precise positioning via wireless light.

[0064] Specifically: Each sensor node in the sensor network updates its own coordinates in real time using a self-localization method and sends the updated coordinates to the cloud to notify the cloud of the current location of each sensor node. The sensor nodes form a sensor network, and each node in the network captures underwater objects. Based on the signals received by the sensor nodes from the underwater objects, the underwater objects are roughly located to obtain their initial coordinates, which are then sent to the cloud. The underwater objects can be underwater research vehicles, vehicles that have fallen into the water, etc., and are not specifically limited here.

[0065] Step S2: Determine the target sensor node in the area where the first coordinate is located based on the first coordinate.

[0066] In this embodiment, since this application has found that when locating underwater objects, the closer the node sending the light signal is to the underwater object, the higher the positioning accuracy, after receiving the first coordinates of the underwater object sent by the sensor node that has captured the underwater object in the cloud, this application determines which sensor nodes are located within the area of ​​the first coordinate based on the first coordinate, and determines the sensor nodes located within the area of ​​the first coordinate as target sensor nodes, and the target sensor nodes are used to accurately locate the underwater object at the first coordinate position.

[0067] Step S3: Emit a light signal through the target sensor node.

[0068] In this embodiment, after determining the target sensor nodes located within the area of ​​the first coordinate in the cloud, each target sensor node is controlled to emit a light signal, which includes at least light intensity information and position information. For example, the target sensor nodes include sensor nodes A1 to A10, and target sensor node Ai emits a light signal ai, where i takes values ​​from 1 to 10.

[0069] Step S4: Determine the target coordinates of the underwater object based on the light signal received by the underwater object.

[0070] In this embodiment, the underwater object at the first coordinate is equipped with a light signal receiver. After each target sensor node emits a light signal, the light signal receiver on the underwater object receives all the light signals emitted by each target sensor node. By analyzing all the received light signals, the accurate underwater coordinates of the underwater object are determined, which is the target coordinates of the underwater object. The analysis of all light signals can be performed by the underwater object itself, which then sends the obtained target coordinates to the cloud. Alternatively, the underwater object can receive all the light signals and send the information to the cloud for analysis to determine the target coordinates of the underwater object. For example, continuing with the example in step S3 above, target sensor nodes A1 to A10 emit a total of 10 light signals, a1 to a10 respectively.

[0071] This invention provides a method for locating underwater objects. First, a coarse location is established for the underwater object based on signals received by sensor nodes, determining its current first coordinates. Then, a target sensor node in the area containing the first coordinate is identified. A light signal is emitted from the target sensor node in the area containing the first coordinate. Finally, a more accurate target coordinate is determined based on the light signal received by the underwater object from the target sensor node in the area containing the first coordinate. Thus, by introducing two positioning methods—first coarsely locating the underwater object, and then using wireless optical positioning to more accurately locate it—the accuracy of underwater object positioning can be effectively improved. Furthermore, this method activates a nearby laser for wireless optical positioning after determining the approximate location of the underwater object. Therefore, the frequency and duration of laser usage are significantly reduced, and the lifespan of the laser is increased. This improves the accuracy of underwater object positioning while reducing costs and avoiding optical pollution caused by prolonged laser operation.

[0072] In conjunction with the above embodiments, in one implementation, the present invention also provides a method for locating underwater objects. In this method for locating underwater objects, step S2 may include steps S21 to S22:

[0073] Step S21: Determine the distance between each sensor node and the first coordinate based on the first coordinate.

[0074] In this embodiment, the number of optical signals required for underwater object positioning is subject to certain requirements, such as 5 or 10 optical signals being sufficient for accurate positioning. To prevent the number of sensor nodes within the first coordinate range of the underwater object from exceeding the required number of optical signals, thus causing excessive laser wear, the following measures are taken: If 5 optical signals are needed for accurate positioning, and there are 15 sensor nodes within the first coordinate range of the underwater object, emitting a single optical signal from each of these 15 nodes would result in 15 optical signals. However, only 5 optical signals are actually required for accurate positioning, and the extra 10 signals constitute a meaningless waste, leading to unnecessary laser wear. Therefore, this application proposes another implementation method for step S2 in the previous embodiment, specifically: after receiving the first coordinates of the underwater object in the cloud, the distance between the location of each sensor node in the sensor network and the first coordinate is determined according to the first coordinates of the underwater object determined by coarse positioning.

[0075] Step S22: Based on the distance, determine the preset number of sensor nodes closest to the first coordinate as target sensor nodes.

[0076] In this embodiment, after determining the distances between the locations of each sensor node in the sensor network and the first coordinate in step S21, a predetermined number of sensor nodes closest to the first coordinate are selected from all sensor nodes based on these distances. These selected sensor nodes are then designated as target sensor nodes for subsequent accurate positioning. The predetermined number can be set according to the actual application scenario and is not specifically limited here; for example, it could be 5, 10, etc. For example, assuming a preset quantity of 10, the sensor nodes in the sensor network include A1 to A100. All sensor nodes are sorted according to distance. Sensor nodes A1, A5, A8, A20, A25, A30, A34, A50, A67, and A95 are the top 10 sensor nodes closest to the first coordinate in the sorted order. A1 is the closest of the 100 sensor nodes to the first coordinate, and A95 is the 10th closest. These 10 sensor nodes are identified as target sensor nodes. Therefore, when determining target sensor nodes, multiple target sensor nodes that are closest to the first coordinate and meet the required number of light signals for accurate positioning can be identified. For example, if only 10 light signals are needed, this application identifies the 10 sensor nodes closest to the first coordinate as target sensor nodes for subsequent accurate positioning of underwater objects.

[0077] In conjunction with the above embodiments, in one implementation, the present invention also provides a method for locating underwater objects. In this method for locating underwater objects, step S2 may include steps S201 to S202:

[0078] Step S201: Based on the first coordinates and the preset length, determine the target area with the first coordinates as the center and the preset length as the radius.

[0079] In this embodiment, regarding one implementation of steps S21 to S22 of step S2, although multiple target sensor nodes closest to the first coordinate and meeting the required number of light signals for accurate positioning are identified, the actual distance between the sensor nodes and the first coordinate is not considered. If a target sensor node is among the closest and highest-ranked sensors to the first coordinate, but is too far from the first coordinate, its positioning performance will be poor, affecting the final accurate positioning result. For example, the optimal positioning range for wireless optical positioning is within 300 meters, requiring 10 light signals for accurate positioning. The two lowest-ranked target sensor nodes among the 10 closest to the first coordinate are 320 meters and 350 meters away from the first coordinate, respectively. Clearly, these two target sensor nodes will affect the final accurate positioning result. To address this problem, this application provides another implementation for step S2: specifically, based on the optimal transmission range of the laser's light signal, half of this transmission range is used as the preset length. After determining the first coordinates of the underwater object, a target area is determined with the first coordinate as the center and the preset length as the radius.

[0080] Step S202: Determine the number of sensor nodes within the target area.

[0081] In this embodiment, after determining the target area with the first coordinate as the center and the preset length as the radius, the number of sensor nodes within the target area is determined.

[0082] Step S203: If the number is less than or equal to a preset number, all sensor nodes within the target area are identified as target sensor nodes.

[0083] In this embodiment, if the number of sensor nodes within the target area is less than or equal to a preset number, all sensor nodes within the target area are designated as target sensor nodes for subsequent accurate positioning. That is, if the number of sensor nodes within the target area is less than or equal to the number of light signals required for accurate positioning, then all sensor nodes within the target area are directly designated as target sensor nodes.

[0084] Step S204: If the number is greater than the preset number, determine the distance between each sensor node in the target area and the first coordinate.

[0085] In this embodiment, if the number of sensor nodes within the target area exceeds a preset number, it indicates that the number of sensor nodes in the target area exceeds the amount of light signals required for accurate positioning. In this case, sensor nodes within the target area can be selected, with those closer to the first coordinate being chosen as the target sensor nodes (because the light signals emitted by these closer sensor nodes can better accurately locate underwater objects), thus ensuring the effectiveness of subsequent accurate positioning. Furthermore, if the number of sensor nodes within the target area exceeds the preset number, the distance between each sensor node within the target area and the first coordinate is determined.

[0086] Step S205: Based on the distance, determine the sensor nodes within the target area that are closest to the first coordinate as target sensor nodes.

[0087] In this embodiment, after determining the distance between the location of each sensor node in the target area and the first coordinate through step S204, a preset number of sensor nodes closest to the first coordinate are selected from all the sensor nodes in the target area based on the distance between the location of each sensor node in the target area and the first coordinate. These selected sensor nodes are then identified as target sensor nodes for subsequent accurate positioning.

[0088] In conjunction with the above embodiments, in one implementation, the present invention also provides a method for locating underwater objects. In this method for locating underwater objects, step S3 may include steps S31 to S34:

[0089] Step S31: When the number is equal to or greater than the preset number, each target sensor node emits a corresponding beam of light signal.

[0090] In this embodiment, if the number of sensor nodes in the target area is determined to be greater than or equal to a preset number through steps S201 to S205 in the previous embodiment, then each target sensor node is controlled to emit a beam of light signal, so that the receiver of the underwater object receives a preset number of light signals within the area where the target area is located.

[0091] Step S32: If the number is less than the preset number, determine the number of target sensor nodes.

[0092] In this embodiment, if the number of sensor nodes in the target area is less than a preset number as determined by steps S201 to S205 in the previous embodiment, and each target sensor node emits a beam of light, the total number of light signals will not reach the required number. In this case, the laser configured for each sensor node is a wireless optical array composed of multiple lasers. When the total number of light signals obtained by each target sensor node emitting a beam of light is insufficient to reach the required number, different lasers within a single target sensor node emit beams of light, thus allowing a single target sensor node to simultaneously emit multiple beams of light to compensate for the insufficient number of light signals. Specifically, if the number of sensor nodes in the target area is less than a preset number as determined by steps S201 to S205 in the previous embodiment, all sensor nodes in the target area will be identified as target sensor nodes, and the specific number of target sensor nodes will be determined at this time.

[0093] Step S33: Determine the target quantity based on the preset quantity and the number of sensor nodes identified as targets.

[0094] In this embodiment, based on the specific number and preset number of all target sensor nodes within the target area determined in step S32, the preset number is subtracted from the specific number of all target sensor nodes within the target area determined in step S32, and then an operation is performed to obtain a corresponding target number. For example, if the preset number is set to 10, and the specific number of all target sensor nodes within the target area determined in step S32 is 8, then the corresponding target number is determined to be 3.

[0095] Step S34: The target number of light signals is emitted through the target sensor node closest to the first coordinate, and a corresponding beam of light is emitted through each of the other target sensor nodes.

[0096] In this embodiment, after determining the corresponding number of targets in step S33, the target sensor node closest to the first coordinate within the target area is controlled to emit a beam of light from the lasers of the target number in the wireless optical array. That is, the target sensor node closest to the first coordinate within the target area will emit a preset number of light signals. At the same time, other target sensor nodes besides the target sensor node closest to the first coordinate within the target area are controlled to emit a beam of light. For example, continuing with the example in step S32 above, the target sensor node closest to the first coordinate within the target area is controlled to emit 3 beams of light, while the remaining 7 beams of light are emitted by the 7 target sensor nodes within the target area, respectively, thereby obtaining 10 beams of light required for positioning.

[0097] In conjunction with the above embodiments, in one implementation, the present invention also provides a method for locating underwater objects. In this method for locating underwater objects, step S4 may include steps S41 to S46:

[0098] Step S41: Determine the receiving power of the channel path of the optical signal based on the optical signal received by the underwater object.

[0099] In this embodiment, the receiver of the underwater object will receive a preset number of optical signals, and for each optical signal, the receiving power of the channel path of the optical signal will be determined based on the information of the optical signal.

[0100] Step S42: Determine the proportion of the received power to the total received power based on the received power.

[0101] In this embodiment, after determining the received power of the channel path of each of the preset number of optical signals, the received power of all channel paths is summed to obtain the total received power. Then, the proportion of the received power of the channel path of each optical signal to the total received power is determined to obtain the proportion corresponding to the channel path of each optical signal.

[0102] Step S43: Determine the weighting factor of the channel path according to the ratio.

[0103] In this embodiment, for the proportion of the channel path of any one of the optical signals in each optical signal, the weighting factor of the channel path to that one optical signal is determined according to the proportion of the channel path of that one optical signal, thereby obtaining a corresponding weighting factor for the channel path of each optical signal.

[0104] Step S44: The received power of the channel path is weighted and corrected by the weighting factor to obtain the target received power of the channel path.

[0105] In this embodiment, after determining a weighting factor corresponding to the channel path of each optical signal in step S43, the implementation method for weighted correction of the received power of the channel path of each optical signal is the same. Here, the weighted correction of the received power of the channel path of one optical signal is used as an example for explanation. The received power of the channel path is weighted and corrected using the weighting factor of the channel path of the optical signal to obtain the target received power of the channel path of the optical signal. Based on the same implementation method, a corresponding target received power can be determined for the channel path of each optical signal.

[0106] Step S45: Based on the target received power of each channel path, select the first number of channel paths with the highest target received power from all channel paths and determine them as the target channel paths.

[0107] In this embodiment, after determining the target received power corresponding to the channel path of each optical signal, the channel paths with the highest target received power are selected from all the channel paths of the optical signals and determined as the target channel paths. For example, assuming the preset number is 10 and the first number is 5, the target received power of the channel paths of the 10 optical signals is calculated, and then the target received power of the channel paths of the 10 optical signals is sorted according to the target received power, and the channel paths of the 5 optical signals with the highest target received power at the top of the sort are selected and determined as the target channel paths.

[0108] Step S46: Determine the target coordinates of the underwater object based on the coordinates corresponding to the target channel path.

[0109] In this embodiment, after determining a first number of target channel paths in step S45, the target coordinates of the underwater object are determined based on the coordinates of the emission points of each optical signal corresponding to the first number of target channel paths. The coordinates of the emission points of the optical signals represent the coordinate positions of the lasers emitting the optical signals. Different lasers in the wireless optical array of the same target sensor node have different coordinate positions, and the coordinate positions of different lasers in a target sensor node can be calculated based on the coordinate positions of the target sensor node. The preferred value for the first number is 5, and the preset number is a value greater than the first number.

[0110] In conjunction with the above embodiments, in one implementation, the present invention also provides a method for locating underwater objects. In this method for locating underwater objects, step S41 may include steps S411 to S412:

[0111] Step S411: By processing the optical signal received by the underwater object, the channel impulse response vector of the optical signal is obtained.

[0112] In this embodiment, the method for processing each received optical signal to obtain the corresponding channel impulse response vector is the same, and a single optical signal is used as an example for explanation. The received optical signal undergoes photoelectric signal conversion and analog-to-digital signal conversion to obtain a baseband signal. Then, the obtained baseband signal is subjected to cyclic prefix removal, fast Fourier transform, and channel estimation algorithm to obtain the corresponding channel frequency domain response. Finally, an inverse fast Fourier transform is performed on the channel frequency domain response to obtain the channel impulse response vector. Based on the same implementation method, a corresponding channel impulse response vector will be obtained for each optical signal received from an underwater object.

[0113] Step S412: Determine the received power of the channel path of the optical signal based on the channel impulse response vector.

[0114] In this embodiment, the received power of the channel path of the optical signal is obtained by processing the channel impulse response vector of the optical signal. Based on the same implementation method, a corresponding received power will be obtained for the channel path of each beam of optical signal received by the underwater object.

[0115] In conjunction with the above embodiments, in one implementation, the present invention also provides a method for locating underwater objects. In this method, step S43 may include: calculating a weighting factor for the channel path by inputting the proportion of the received power of the channel path to the total received power into a first algorithm, wherein the first algorithm is:

[0116]

[0117] Among them, h norm,i (i) represents the received power of the i-th channel path, w′ i This represents the weighting factor for the i-th channel path.

[0118] In this embodiment, after calculating the proportion of the received power of the optical signal's channel path to the total received power, this proportion is substituted into the first algorithm for calculation, thereby calculating the weighting factor of the optical signal's channel path.

[0119] The first algorithm is:

[0120] Among them, h norm,i (i) represents the received power of the i-th channel path, w′ i This represents the weighting factor for the i-th channel path.

[0121] In conjunction with the above embodiments, in one implementation, the present invention also provides a method for locating underwater objects. In this method, step S44 may include: obtaining the target received power of the channel path by substituting the weighting factor of the channel path and the total received power into a second algorithm for weighted correction calculation, wherein the second algorithm is:

[0122]

[0123] in, Let P be the target received power for the i-th channel path. r For the total received power, h LOS This represents the normalized amplitude of the line-of-sight link.

[0124] In this embodiment, after calculating the weighting factor of the channel path of the optical signal, the weighting factor and the total received power are substituted into the second algorithm for weighted correction calculation, so as to calculate the target received power of the channel path of the optical signal.

[0125] The second algorithm is as follows:

[0126]

[0127] in, Let P be the target received power for the i-th channel path. r For the total received power, h LOS This is the normalized amplitude of the line-of-sight link. This normalized amplitude changes with the channel quality. A very strong transmit power will be greatly attenuated when it is transmitted in a channel with poor channel quality, and the received power will be smaller. However, if a small transmit power is transmitted in a channel with good channel quality, the received power will remain unchanged or increase.

[0128] In conjunction with the above embodiments, in one implementation, the present invention also provides a method for locating underwater objects. In this method for locating underwater objects, step S46 may include steps S461 to S465:

[0129] Step S461: Calculate the Jacobian matrix and the deviation vector using the coordinates corresponding to the target channel path to obtain the values ​​of the Jacobian matrix and the deviation vector.

[0130] In this embodiment, as Figure 3 As shown, Figure 3 This is another flowchart illustrating a method for locating underwater objects according to an embodiment of the present invention. The method determines indices corresponding to the coordinates of the target channel path: β = [β1, β2]. T .in

[0131] index = 1: β = [x1+1, y1-1] T The index of the coordinates corresponding to the path of the target signal with the highest target received power;

[0132] index = 2: β = [x² - 1, y² - 1] T The index of the coordinates corresponding to the target signal path with the second highest target received power;

[0133] index = 3: β = [x³ + 1, y³ + 1] T The index of the coordinates corresponding to the target signal path with the third highest target received power;

[0134] index = 4: β = [x⁴ - 1, y⁴ + 1]T The index of the coordinates corresponding to the target signal path with the fourth highest target received power;

[0135] index = 5: β = [x5, y5] T The index of the coordinates corresponding to the path of the target signal with the 5th highest target received power; (x i ,y i If , then it represents the specific coordinate position corresponding to the target channel path with the highest target received power (i). If i is 1, then it represents the specific coordinate position corresponding to the target channel path with the highest target received power.

[0136] The formula for calculating the Jacobian matrix J is: in:

[0137]

[0138]

[0139] The formula for calculating the deviation vector is:

[0140]

[0141] Where θ is the polar angle formed by the optical signal transmitting point and the receiving point, ω is the azimuth angle formed by the optical signal transmitting point and the receiving point, and h is the height of the receiver. Let m be the emission power of the i-th laser, m be the Lambertian radiation order, A be the effective area of ​​the receiver, and T be the emission power of the i-th laser. s (ψ i ) represents the optical filter gain, g(ψ) i ) represents the concentrator gain, ψ i Let β1, β2, and β3 be the angle between the receiver plane normal vector and the line connecting the receiver and transmitter; in the calculation process, β1, β2, and β3 are... j The value of β is related to the value of i in the Jacobian matrix. When i is n, β1 represents β1 in β corresponding to index = n, and β2 represents β2 in β corresponding to index = n. When j is 1, β... j This represents β1 in β when index = n, and β when j takes the value 2. j This represents β2 in β when index = n, where n takes the values ​​1, 2, 3, 4, and 5.

[0142] In this embodiment, the values ​​of the Jacobian matrix and the deviation vector are obtained by substituting the coordinates corresponding to the target channel path into the calculation formulas of the Jacobian matrix and the deviation vector.

[0143] Step S462: Update the coordinates of the underwater object and the coordinates of the target channel path according to the values ​​of the Jacobian matrix and the deviation vector.

[0144] In this embodiment, the expression for the coordinate update algorithm is:

[0145] β′=β+(J T J) -1 J T ΔP

[0146] Where J represents the value of the Jacobian matrix; ΔP represents the value of the deviation vector; β represents the index of the coordinates in the previous iteration, which can represent the index of the underwater object's coordinates or the index of the laser corresponding to the target channel path. When the index of the underwater object's coordinates is 0, for the first iteration calculation, the first coordinate of the underwater object is determined as the coordinate in the previous iteration, and at this time, the value of β is the index of the first coordinate; β′ represents the index of the coordinates in the current iteration, which can represent the index of the underwater object's coordinates or the index of the laser corresponding to the target channel path.

[0147] In this embodiment, the calculated values ​​of the Jacobian matrix and the deviation vector are input into the coordinate update algorithm. Simultaneously, the coordinates of the target channel path from the previous iteration are also input into the coordinate update algorithm to obtain the index of the new coordinates of the target channel path, thus yielding the new coordinates of the target channel path. During the initial iterative calculation of the new coordinates of the target channel path based on the Jacobian matrix and deviation vector values, the coordinates of the target channel path before the iteration calculation are performed are determined as the coordinates from the previous iteration. The calculated values ​​of the Jacobian matrix and the deviation vector are input into the coordinate update algorithm. Simultaneously, the coordinates of the underwater object from the previous iteration are also input into the coordinate update algorithm to obtain the index of the new coordinates of the underwater object, thus yielding the new coordinates of the underwater object. The expression for the index of the underwater object's coordinates is index = 0: β = [x0, y0] T In the initial iterative calculation of the new coordinates of the target channel path based on the values ​​of the Jacobian matrix and the deviation vector, the first coordinate of the underwater object is determined to be the coordinate of the previous iteration.

[0148] Step S463: Determine the number of iterations for calculating the coordinates of the underwater object.

[0149] In this embodiment, the number of iterations required to calculate the new coordinates of the underwater object based on the values ​​of the Jacobian matrix and the deviation vector is determined.

[0150] Step S464: If the number of iterations has not reached the preset number, return to step S461.

[0151] Step S465: When the number of iterations reaches the preset number, the last coordinate of the underwater object is determined as the target coordinate of the underwater object.

[0152] In this embodiment, if the preset number of iterations has not been reached, the process returns to step S461 to continue a new round of iterations. Specifically: the latest coordinates corresponding to the target channel path are calculated using the formulas for calculating the Jacobian matrix and the deviation vector, resulting in the new values ​​of the Jacobian matrix and the deviation vector for the current iteration. These values ​​are then fed into the coordinate update algorithm, along with the previous coordinates of the target channel path, to obtain the index of the new coordinates of the target channel path for the current iteration. Thus, the new coordinates of the target channel path can be obtained.

[0153] The calculated values ​​of the new Jacobian matrix and the new deviation vector for the current iteration are input into the coordinate update algorithm. Simultaneously, the coordinates of the underwater object from the previous iteration are also input into the coordinate update algorithm to obtain the index of the new coordinates of the underwater object in the current iteration, thus yielding the new coordinates of the underwater object. Then, the number of iterations for calculating the new coordinates of the underwater object based on the Jacobian matrix and deviation vector values ​​is determined again. If the preset number of iterations has not been reached, the process returns to step S461 for sequential execution, calculating the Jacobian matrix and deviation vector values ​​for the new iteration. Based on these values, the coordinates corresponding to the target channel path and the underwater object for the new iteration are determined. This process continues until the preset number of iterations is reached. At this point, the coordinates of the underwater object obtained from the last calculation are determined as the target coordinates of the underwater object, which are the final precise coordinates of the underwater object. The preset number of times can be set according to the actual application scenario, and there is no specific limit here. For example, it can be set to 6 times, 8 times, 10 times, etc.

[0154] Based on the same inventive concept, one embodiment of the present invention provides a system for locating underwater objects, such as... Figure 4 As shown, the system 400 includes:

[0155] The first coordinate determination module 401 is used to determine the first coordinates of an underwater object based on the signals received by the sensor node.

[0156] The target sensor node determination module 402 is used to determine the target sensor node in the area where the first coordinate is located based on the first coordinate.

[0157] The optical signal transmitting module 403 is used to emit optical signals through the target sensor node.

[0158] The target coordinate determination module 404 is used to determine the target coordinates of the underwater object based on the light signal received by the underwater object.

[0159] Optionally, the target sensor node determination module 402 includes:

[0160] The distance determination module is used to determine the distance between each sensor node and the first coordinate based on the first coordinate.

[0161] The target sensor node determination submodule is used to determine a preset number of sensor nodes that are closest to the first coordinate as target sensor nodes based on the distance.

[0162] Optionally, the target sensor node determination module 402 includes:

[0163] The target area determination module is used to determine a target area with the first coordinate as the center and the preset length as the radius, based on the first coordinate and the preset length.

[0164] A quantity determination module is used to determine the number of sensor nodes within the target area;

[0165] The first target sensor node determination module is used to determine all sensor nodes in the target area as target sensor nodes when the number is less than or equal to a preset number.

[0166] The first distance determination module is used to determine the distance between each sensor node in the target area and the first coordinate when the number is greater than the preset number.

[0167] The second target sensor node determination module is used to determine the sensor nodes within the target area that are closest to the first coordinates as target sensor nodes based on the distance.

[0168] Optionally, the optical signal transmitting module 403 includes:

[0169] The first optical signal transmitting module is used to emit a corresponding beam of optical signal for each target sensor node when the number is equal to or greater than the preset number.

[0170] The first quantity determination module is used to determine the number of target sensor nodes when the number is less than the preset number;

[0171] The target quantity determination module is used to determine the target quantity based on the preset quantity and the number of sensor nodes identified as targets;

[0172] The second optical signal transmitting module is used to emit the target number of optical signals through the target sensor node closest to the first coordinate, and to emit a corresponding beam of optical signal through each of the other target sensor nodes.

[0173] Optionally, the target coordinate determination module 404 includes:

[0174] The receiving power determination module is used to determine the receiving power of the optical signal channel path based on the optical signal received by the underwater object.

[0175] The ratio determination module is used to determine the ratio of the received power to the total received power based on the received power.

[0176] A weighting factor determination module is used to determine the weighting factor of the channel path according to the ratio;

[0177] The target received power determination module is used to weight and correct the received power of the channel path using the weighting factor to obtain the target received power of the channel path.

[0178] The target channel path determination module is used to select the first number of channel paths with the highest target received power from all channel paths and determine them as the target channel paths based on the target received power of each channel path.

[0179] The target coordinate determination submodule is used to determine the target coordinates of the underwater object based on the coordinates corresponding to the target channel path.

[0180] Optionally, the received power determination module includes:

[0181] The channel impulse response vector determination module is used to obtain the channel impulse response vector of the optical signal by processing the optical signal received by the underwater object;

[0182] The received power determination submodule is used to determine the received power of the optical signal's channel path based on the channel impulse response vector.

[0183] Optionally, the weighting factor determination module includes:

[0184] The weighting factor determination submodule is used to obtain the weighting factor of the channel path by inputting the proportion of the received power of the channel path to the total received power into the first algorithm for calculation. The first algorithm is as follows:

[0185]

[0186] Among them, h norm,i (i) represents the received power of the i-th channel path, w′ i This represents the weighting factor for the i-th channel path.

[0187] Optionally, the target received power determination module includes:

[0188] The target received power determination submodule is used to obtain the target received power of the channel path by inputting the weighting factor of the channel path and the total received power into a second algorithm for weighted correction calculation. The second algorithm is as follows:

[0189]

[0190] in, Let P be the target received power for the i-th channel path. r For the total received power, h LOs This represents the normalized amplitude of the line-of-sight link.

[0191] Optionally, the target coordinate determination submodule includes:

[0192] The vector matrix calculation module is used to calculate the Jacobian matrix and the deviation vector using the coordinates corresponding to the target channel path, and to obtain the values ​​of the Jacobian matrix and the deviation vector.

[0193] The coordinate update module is used to update the coordinates of the underwater object and the coordinates of the target channel path based on the values ​​of the Jacobian matrix and the deviation vector.

[0194] The iteration count determination module is used to determine the number of iterations required to calculate the coordinates of the underwater object.

[0195] A control module is used to control the execution of the vector matrix calculation module when the number of iterations has not reached a preset number.

[0196] The first target coordinate determination module is used to determine the last coordinate of the underwater object as the target coordinate of the underwater object when the number of iterations reaches the preset number.

[0197] As the system implementation is basically similar to the method implementation, it is described in a relatively simple way. For relevant details, please refer to the description of the system implementation.

[0198] It should be noted that, for the sake of simplicity, the method embodiments are all described as a series of actions. However, those skilled in the art should understand that the embodiments of the present invention are not limited to the described order of actions, because according to the embodiments of the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions involved are not necessarily essential to the embodiments of the present invention.

[0199] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0200] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, embodiments of the present invention can take the form of entirely hardware embodiments, entirely software embodiments, or embodiments combining software and hardware aspects. Furthermore, embodiments of the present invention can take the form of computer program products implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0201] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, terminal devices (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing terminal device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing terminal device, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0202] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing terminal device to operate in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0203] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal equipment, causing a series of operational steps to be performed on the computer or other programmable terminal equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable terminal equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0204] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present invention.

[0205] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0206] The above provides a detailed description of the method and system for underwater object positioning provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for locating underwater objects, characterized in that, The method includes: The first coordinates of the underwater object are determined based on the signals received by the sensor nodes; Based on the first coordinates, determine the target sensor node in the area where the first coordinates are located; The target sensor node emits a light signal; The target coordinates of the underwater object are determined based on the optical signal received by the underwater object.

2. The method for locating an underwater object according to claim 1, characterized in that, Determining the target sensor node in the area where the first coordinate is located based on the first coordinate includes: Based on the first coordinate, determine the distance between each sensor node and the first coordinate; Based on the distance, a preset number of sensor nodes that are closest to the first coordinate are determined as target sensor nodes.

3. The method for locating underwater objects according to claim 1, characterized in that, Determining the target sensor node in the area where the first coordinate is located based on the first coordinate includes: Based on the first coordinates and the preset length, a target area is determined with the first coordinates as the center and the preset length as the radius. Determine the number of sensor nodes within the target area; If the number is less than or equal to a preset number, all sensor nodes within the target area are identified as target sensor nodes. If the number is greater than the preset number, determine the distance between each sensor node in the target area and the first coordinate. Based on the distance, the sensor nodes within the target area that are closest to the first coordinate are determined as target sensor nodes.

4. The method for locating an underwater object according to claim 3, characterized in that, The light signal emitted by the target sensor node includes: When the number is equal to or greater than the preset number, each target sensor node emits a corresponding beam of light signal; If the number is less than the preset number, determine the number of target sensor nodes; The target quantity is determined based on the preset quantity and the number of sensor nodes identified as targets; The target number of light signals is emitted by the target sensor node closest to the first coordinate, and a corresponding beam of light is emitted by each of the other target sensor nodes.

5. The method for locating an underwater object according to claim 1, characterized in that, Determining the target coordinates of the underwater object based on the optical signal received by the underwater object includes: Based on the optical signal received by the underwater object, determine the received power of the optical signal channel path; Based on the received power, determine the proportion of the received power to the total received power; Based on the stated ratio, determine the weighting factor for the channel path; The received power of the channel path is weighted and corrected by the weighting factor to obtain the target received power of the channel path; Based on the target received power of each channel path, the first number of channel paths with the highest target received power are selected from all channel paths and determined as the target channel paths; The target coordinates of the underwater object are determined based on the coordinates corresponding to the target channel path.

6. The method for locating an underwater object according to claim 5, characterized in that, Determining the received power of the optical signal's channel path based on the optical signal received by the underwater object includes: By processing the optical signal received by the underwater object, the channel impulse response vector of the optical signal is obtained; The received power of the optical signal's channel path is determined based on the channel impulse response vector.

7. The method for locating an underwater object according to claim 5, characterized in that, Based on the stated ratio, the weighting factor for the channel path is determined, including: The weighting factor of the channel path is obtained by substituting the proportion of the received power of the channel path to the total received power into the first algorithm for calculation. The first algorithm is as follows: Among them, h norm,i (i) represents the received power of the i-th channel path, w′ i This represents the weighting factor for the i-th channel path.

8. The method for locating an underwater object according to claim 5, characterized in that, The target received power of the channel path is obtained by weighting and correcting the received power of the channel path using the weighting factor, including: The target received power of the channel path is obtained by substituting the weighting factor of the channel path and the total received power into the second algorithm for weighted correction calculation. The second algorithm is as follows: in, Let P be the target received power for the i-th channel path. r For the total received power, h LOS This represents the normalized amplitude of the line-of-sight link.

9. A method for locating an underwater object according to claim 5, characterized in that, Determining the target coordinates of the underwater object based on the coordinates corresponding to the target channel path includes: The Jacobian matrix and the deviation vector are calculated using the coordinates corresponding to the target channel path to obtain the values ​​of the Jacobian matrix and the deviation vector. Based on the values ​​of the Jacobian matrix and the deviation vector, update the coordinates of the underwater object and the coordinates of the target channel path; The number of iterative calculations to determine the coordinates of the underwater object; If the number of iterations has not reached the preset number, return to the step: calculate the Jacobian matrix and the deviation vector using the coordinates corresponding to the target channel path to obtain the values ​​of the Jacobian matrix and the deviation vector; When the number of iterations reaches the preset number, the coordinates of the underwater object at the last iteration are determined as the target coordinates of the underwater object.

10. A system for locating underwater objects, characterized in that, The system includes: The first coordinate determination module is used to determine the first coordinates of the underwater object based on the signals received by the sensor node. The target sensor node determination module is used to determine the target sensor node in the area where the first coordinate is located based on the first coordinate. An optical signal transmitting module is used to emit optical signals through the target sensor node; The target coordinate determination module is used to determine the target coordinates of the underwater object based on the light signal received by the underwater object.

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