Underwater positioning method and system based on hyperbola positioning
By using the hyperbolic positioning method and TDOA technology, and constructing a hyperbolic equation by measuring the time difference of three receivers, the problems of low underwater positioning accuracy and high system complexity are solved, achieving high-precision and low-cost underwater animal positioning, which is suitable for a variety of underwater applications.
Patent Information
- Application Number
- CN202511233282.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-01
- Publication Date
- 2025-11-14
AI Technical Summary
Existing underwater positioning technologies suffer from low accuracy and are highly susceptible to interference in complex underwater environments. They are also costly and easily affected by environmental factors, making it difficult to guarantee positioning accuracy and robustness.
The hyperbolic positioning method is adopted, which uses three receivers to measure the time difference of signal arrival, achieves time synchronization through wireless or wired connection, constructs hyperbolic equations, and solves the simultaneous equations by numerical methods to determine the location of underwater animals.
It improves the accuracy and reliability of underwater positioning, simplifies the system structure, reduces costs, and can effectively cope with multipath interference and signal propagation delay, making it suitable for scenarios such as marine research, fisheries management, and underwater engineering.
Smart Images
Figure CN120949167A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of underwater positioning technology, and in particular to an underwater positioning method and system based on hyperbolic positioning. Background Technology
[0002] Underwater positioning systems have important applications in marine research, fisheries management, and underwater engineering. Existing underwater positioning technologies mainly rely on sonar and GPS, but these technologies suffer from low accuracy and susceptibility to interference in complex underwater environments. Time Difference of Arrival (TDOA) technology, which utilizes the time difference of arrival of signals from multiple receivers for precise positioning, has become an effective solution. However, traditional TDOA positioning methods have limitations in handling multipath interference and signal propagation delays.
[0003] In existing technologies, underwater acoustic positioning systems typically require high-precision time synchronization and complex computing equipment, which increases system costs and makes them susceptible to environmental factors in practical applications, making it difficult to guarantee positioning accuracy. Therefore, there is an urgent need for a new technical solution that can simplify the system structure, reduce costs, and improve the system's robustness and reliability while ensuring positioning accuracy. Summary of the Invention
[0004] This disclosure aims to solve at least one of the technical problems existing in the prior art, and proposes a hyperbolic positioning method and system for underwater positioning.
[0005] In a first aspect, this disclosure provides a hyperbolic positioning method for underwater positioning, comprising the following steps:
[0006] S1, three receivers are placed at predetermined positions to receive signals from the underwater animal signal transmitter and measure the time difference of the signal arriving at each receiver;
[0007] S2, calculate the distance difference between the signal source and the receiver based on the measured time difference;
[0008] S3. Using the receiver's position coordinates and the calculated distance difference, a hyperbolic equation for positioning is constructed.
[0009] S4. Solve the simultaneous hyperbolic equations using numerical methods to obtain the specific coordinates of the underwater animal's location in the water.
[0010] Preferably, the method for measuring the time difference in S1 specifically includes:
[0011] The time difference is calculated by using three receivers and the arrival times between them.
[0012] Preferably, S1 specifically includes:
[0013] The receivers are synchronized in time via wireless communication or wired connection.
[0014] Preferably, S2 specifically includes:
[0015] The signal processing unit calculates the time difference of the signal arriving at each receiver, and uses the signal propagation speed to calculate the distance difference between the signal source and each receiver.
[0016] Preferably, S1 specifically includes:
[0017] Establish a coordinate system and confirm that the coordinates of the three receivers are (x1, y1), (x2, y2), and (x3, y3).
[0018] The reception times of the three receivers are t1, t2, and t3, respectively. The differences between them yield three time differences: |t1-t2|, |t2-t3|, and |t1-t3|.
[0019] Preferably, S3 specifically includes:
[0020] Constructing the hyperbola equation - =1, where a>0, b>0;
[0021] Similarly, construct two more sets of hyperbolic equations in the same manner.
[0022] Preferably, S4 specifically includes:
[0023] Let the coordinates of the marker point T be (x0, y0), and its distance from the marker point T to the specified curve be s. Let the coordinates of the moving point on the curve be (x, y), and s = ;
[0024] From the equation of the curve, we can find y=f(x). Substituting this into the above equation, we get:
[0025] s= ;
[0026] remember Let g(x);
[0027] That is: s=g(x), s'=g'(x);
[0028] Let s'=0, find x, and let x be x1 at this time; according to the sign of g'(x) when x→+x1 (approaching x1 from the direction greater than x1) and x→-0 (approaching x1 from the direction less than x1), we can determine the nature of the extreme point of x1 and get s minimum=g(x1);
[0029] Similarly, the other two curves can be found.
[0030] Preferably, S1 specifically includes:
[0031] The transmitter is used as the excitation source, and three pairs of structural response signals are collected by three receivers respectively. All structural response signals are normalized to eliminate errors caused by the performance differences of each sensor.
[0032] The normalization formula is as follows:
[0033] y(t)=
[0034] Where x(t) is the structural response signal, Max is the maximum value of the structural response signal x(t), and y(t) is the normalized structural response signal.
[0035] The present invention also provides an underwater positioning system based on hyperbolic positioning, which can be used to implement the above-mentioned underwater animal positioning method based on hyperbolic positioning. The system includes:
[0036] The signal transceiver module is used to place three receivers at predetermined positions to receive signals from the underwater animal signal transmitter and measure the time difference of the signal arrival at each receiver.
[0037] The distance calculation module is used to calculate the distance difference between the signal source and the receiver based on the measured time difference;
[0038] The equation building module is used to construct a hyperbolic equation for positioning using the receiver's position coordinates and the calculated distance difference.
[0039] The solver module is used to solve a set of hyperbolic equations using numerical methods to obtain the specific coordinates of the underwater animal's location in the water. Attached Figure Description
[0040] Figure 1 A flowchart of a hyperbolic positioning method for underwater positioning provided in this disclosure embodiment;
[0041] Figure 2 This is a schematic diagram of a signal transmitter and receiver provided in an embodiment of this disclosure. Detailed Implementation
[0042] To enable those skilled in the art to better understand the technical solutions of this disclosure, the disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0043] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure are not intended to indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an,” “a,” or “the,” and similar terms are not intended to limit the quantity, but rather to indicate the presence of at least one. The terms “comprising,” “including,” or “including,” and similar terms mean that the element or object preceding the term encompasses the elements or objects listed following the term and their equivalents, without excluding other elements or objects. The terms “connected,” “linked,” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” and “right,” etc., are used only for relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described object changes.
[0044] In the various figures, the same elements are represented by similar reference numerals. For clarity, not all parts in the figures are drawn to scale. Furthermore, some well-known parts may not be shown in the figures.
[0045] Many specific details of this disclosure, such as the structure, materials, dimensions, processing methods, and techniques of the components, are described below to provide a clearer understanding of the disclosure. However, as those skilled in the art will understand, this disclosure may be implemented without following these specific details.
[0046] like Figure 1 and Figure 2 As shown, this embodiment of the invention provides a hyperbolic positioning method for underwater positioning, including the following steps:
[0047] S1, three receivers are placed at predetermined positions to receive signals from the underwater animal signal transmitter and measure the time difference of the signal arriving at each receiver;
[0048] S2, calculate the distance difference between the signal source and the receiver based on the measured time difference;
[0049] S3. Using the receiver's position coordinates and the calculated distance difference, a hyperbolic equation for positioning is constructed.
[0050] S4. Solve the simultaneous hyperbolic equations using numerical methods to obtain the specific coordinates of the underwater animal's location in the water.
[0051] It should be noted that the technical solution disclosed herein does not impose any restrictions on the order of the above steps, that is, the execution order of each step can be arranged arbitrarily.
[0052] By using three receivers arranged at known positions and combining the TDOA (Time Difference of Arrival) technology and the hyperbolic positioning method, the present invention can achieve high-precision underwater animal positioning in a complex underwater environment.
[0053] In a preferred embodiment, time synchronization between the receivers is achieved through wireless communication or wired connection, so as to ensure accurate measurement of the time difference of signal arrival. The signal processing unit measures the time difference of the signal arriving at each receiver, and calculates the distance difference between the signal source and each receiver using the signal propagation speed.
[0054] Among them, S1 specifically includes:
[0055] Taking the transmitter as the excitation source, three pairs of structural response signals collected by the three receivers respectively are normalized for all the structural response signals to eliminate the errors caused by the performance differences of each sensor;
[0056] The normalization processing formula is as follows:
[0057] y(t)=
[0058] Where, x(t) is the structural response signal, Max is the maximum value of the structural response signal x(t), and y(t) is the normalized structural response signal.
[0059] In a preferred embodiment, a hyperbolic equation is constructed by a calculation unit. Specifically, hyperbolic equations are constructed using the positions of two receivers and the distance difference between them and the signal source. These hyperbolic equations describe the possible position ranges of the signal source. Then, these hyperbolic equations are solved simultaneously through a numerical solution method to obtain the signal source, that is, the specific position coordinates of the underwater animal. The specific calculation formula is as follows:
[0060] Hyperbolic equation: a represents the distance from the vertex of the hyperbola to the origin (real semi-axis), b represents the imaginary semi-axis of the hyperbola, c represents the distance from the focus to the origin (semi-focal length), and a, b, c satisfy the relationship a² + b² = c², where a < c. The hyperbola is x² / a² - y² / b² = 1. The standard equation of the hyperbola is derived using the distance formula between two points.
[0061] Let the focal length of the hyperbola be 2c, then the coordinates of the two foci are (-c, 0) and (c, 0), respectively.
[0062] First, three receivers are arranged on the shore and placed in the coordinate system as M1(x1, y1), M2(x2, y2), M3(x3, y3).
[0063] The distance ML1 between receivers M1 and M2 = .
[0064] Then the semi-focal length of the hyperbola is c = ML1 / 2.
[0065] Let the marker point T (transmitter) be a point on the hyperbola. After the transmitter transmits a signal, three receivers will successively receive the time count values transmitted by the transmitter. Since the three receivers M1, M2, and M3 are at different positions, their times are also different. Therefore, the time differences are calculated by subtracting the received times t1, t2, and t3 from each pair of receivers: T1 = |t1 - t2| seconds, T2 = |t2 - t3| seconds, and T3 = |t1 - t3| seconds. The underwater velocity of the sound wave is V. S The distances between the three receivers can be calculated as MT1 = T1 * V. S MT2=T1*V S MT3=T1*V S .
[0066] Based on the properties of a hyperbola, let the absolute value of the difference between point T and the two foci be 2a. Then a = |MT1 - MT2| / 2.
[0067] According to the formula a² + b² = c², we can get b = √{(c)² - [a]²}.
[0068] With these three parameters a, b, and c determined, the hyperbolic function between M1 and M2 can be confirmed. - =1, and similarly, we can derive M2, M3, and the two hyperbolas between M3 and M1.
[0069] After obtaining the three hyperbolas, calculations are performed to retain the hyperbola closest to T from each hyperbola, forming three and a half hyperbolas. In principle, these curves will form an intersecting region:
[0070] The coordinates of the marked point T are (x0, y0), and its distance to the first hyperbola is s. The coordinates of the moving point on the curve are (x, y), and s = From the equation of the curve, we can find y=f(x). Substituting this into the above equation, we get:
[0071] s= It's worth remembering. Let g(x) be the denoted s; that is, s = g(x) and s' = g'(x).
[0072] Let s' = 0, and find x. Let's denote this x as x1. Based on the sign of g'(x) when x → +x1 (approaching x1 from the direction greater than x1) and x → -0 (approaching x1 from the direction less than x1), we can determine the nature of the extreme point x1. s is minimum = g(x1). Similarly, we can find the other two curves.
[0073] Finally, obtain the three minimum coordinates of s (x1', y1'), (x2', y2'), and (x3', y3'), draw a triangle, and find the coordinates of the midpoint of the triangle:
[0074] x´´= (x1´+x2´+x3´) / 3
[0075] y´´= (y1´+y2´+y3´) / 3
[0076] The final location coordinates of the marker T are (x´´,y´´).
[0077] The underwater animal localization system and method based on TDOA of the present invention have the following advantages:
[0078] (1) It improves the accuracy and reliability of underwater positioning, and can accurately locate underwater animals in complex underwater environments;
[0079] (2) The system has a simple structure, is easy to implement and maintain, and reduces the cost of the system;
[0080] (3) By using time synchronization and signal processing techniques, the problems of multipath interference and signal propagation delay can be effectively addressed, thereby improving the robustness of the system;
[0081] (4) It is applicable to a variety of underwater application scenarios, including marine research, fisheries management and underwater engineering.
[0082] This invention also provides an underwater positioning system based on hyperbolic positioning, which can be used to implement the above-mentioned underwater animal positioning method based on hyperbolic positioning. The system includes:
[0083] The signal transceiver module is used to place three receivers at predetermined positions to receive signals from the underwater animal signal transmitter and measure the time difference of the signal arrival at each receiver.
[0084] The distance calculation module is used to calculate the distance difference between the signal source and the receiver based on the measured time difference;
[0085] The equation building module is used to construct a hyperbolic equation for positioning using the receiver's position coordinates and the calculated distance difference.
[0086] The solver module is used to solve a set of hyperbolic equations using numerical methods to obtain the specific coordinates of the underwater animal's location in the water.
[0087] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.
[0088] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of this disclosure, and this disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this disclosure, and these modifications and improvements are also considered to be within the scope of protection of this disclosure.
Claims
1. A hyperbolic positioning method for underwater positioning, characterized in that, Includes the following steps: S1, three receivers are placed at predetermined positions to receive signals from the underwater animal signal transmitter and measure the time difference of the signal arriving at each receiver; S2, calculate the distance difference between the signal source and the receiver based on the measured time difference; S3. Using the receiver's position coordinates and the calculated distance difference, a hyperbolic equation for positioning is constructed. S4. Solve the simultaneous hyperbolic equations using numerical methods to obtain the specific coordinates of the underwater animal's location in the water.
2. The underwater animal localization method based on hyperbolic positioning according to claim 1, characterized in that, The method for measuring the time difference in S1 specifically includes: The time difference is calculated by using three receivers and the arrival times between them.
3. The underwater animal localization method based on hyperbolic positioning according to claim 1, characterized in that, S1 specifically includes: The receivers are synchronized in time via wireless communication or wired connection.
4. The underwater animal localization method based on hyperbolic positioning according to claim 1, characterized in that, S2 specifically includes: The signal processing unit calculates the time difference of the signal arriving at each receiver, and uses the signal propagation speed to calculate the distance difference between the signal source and each receiver.
5. The underwater animal localization method based on hyperbolic positioning according to claim 1, characterized in that, S1 specifically includes: Establish a coordinate system and confirm that the coordinates of the three receivers are (x1, y1), (x2, y2), and (x3, y3). The reception times of the three receivers are t1, t2, and t3, respectively. The differences between them yield three time differences: |t1-t2|, |t2-t3|, and |t1-t3|.
6. The underwater animal localization method based on hyperbolic positioning according to claim 5, characterized in that, S3 specifically includes: Constructing the hyperbola equation - =1, where a>0, b>0; Similarly, construct two more sets of hyperbolic equations in the same manner.
7. The underwater animal localization method based on hyperbolic positioning according to claim 6, characterized in that, S4 specifically includes: Let the coordinates of the marker point T be (x0, y0), and its distance from the marker point T to the specified curve be s. Let the coordinates of the moving point on the curve be (x, y), and s = ; From the equation of the curve, we can find y=f(x). Substituting this into the above equation, we get: s= ； remember Let g(x); That is: s=g(x), s'=g'(x); Let s'=0, find x, and denote x as x1 at this time; based on the sign of g'(x) when x→+x1 and x→-x1, we can determine the nature of the extreme point x1 and obtain s minimum=g(x1); Similarly, the other two curves can be found.
8. The underwater animal localization method based on hyperbolic positioning according to claim 1, characterized in that, S1 specifically includes: The transmitter is used as the excitation source, and three pairs of structural response signals are collected by three receivers respectively. All structural response signals are normalized to eliminate errors caused by the performance differences of each sensor. The normalization formula is as follows: y(t)= Where x(t) is the structural response signal, Max is the maximum value of the structural response signal x(t), and y(t) is the normalized structural response signal.
9. A hyperbolic positioning underwater positioning system, characterized in that, The system can be used to implement the underwater animal localization method based on hyperbolic positioning as described in any one of claims 1 to 8, and the system includes: The signal transceiver module is used to place three receivers at predetermined positions to receive signals from the underwater animal signal transmitter and measure the time difference of the signal arrival at each receiver. The distance calculation module is used to calculate the distance difference between the signal source and the receiver based on the measured time difference; The equation building module is used to construct a hyperbolic equation for positioning using the receiver's position coordinates and the calculated distance difference. The solver module is used to solve a set of hyperbolic equations using numerical methods to obtain the specific coordinates of the underwater animal's location in the water.