Vibration reduction LOS guidance method for curve tracking control of underactuated unmanned ship

Abstract

The invention provides a vibration reduction LOS guidance method for curve tracking control of an underactuated unmanned ship, and relates to the field of robustness artificial intelligence. The method comprises the following steps: acquiring an optimal path parameter corresponding to the underactuated unmanned ship based on an iterative approximation numerical solution method; introducing a tracking error item and a tracking error speed item into drift angle estimation compensation; based on the drift angle estimation compensation, designing a self-adaptive vibration reduction LOS algorithm, and obtaining an expected heading angle of the unmanned ship by combining optimal path parameters; designing a sliding mode surface in combination with the expected heading angle, designing a nonlinear sliding mode controller, and generating a control torque; and carrying out expected heading tracking on the underactuated unmanned ship based on the control moment. According to the invention, the problem that accurate path tracking and stable navigation are difficult to realize in the prior art in the case of time-varying environment interference is solved.

Description

Technical Field

[0001] This application relates to the field of robust artificial intelligence, and in particular to a vibration-reducing LOS guidance method for curve tracking control of underactuated unmanned surface vessels. Background Technology

[0002] With the deepening of marine resource development and marine scientific research, unmanned surface vessels (USVs), as an efficient, flexible, and reusable marine operation platform, are finding increasingly wide applications, covering many fields such as marine environmental monitoring, marine surveying, maritime search and rescue, marine resource exploration, and military patrol. However, unmanned surface vessels (USVs) often face complex marine environmental disturbances during missions, such as time-varying factors like wind, waves, and currents. These disturbances not only alter the USV's trajectory and reduce its path-tracking accuracy but also threaten its navigation safety, severely limiting its operational efficiency and application effectiveness. Due to the limitations of their own propulsion systems, underactuated USVs can only directly control their bow turning and forward motion, unable to control lateral movement. This poses a challenge to high-precision path tracking and stable navigation when facing time-varying environmental disturbances. Most existing guidance methods only utilize the integral of the lateral tracking error to compensate for lateral drift caused by environmental loads and hydrodynamics, leading to significant lateral tracking overshoot and oscillations. Therefore, a vibration-reducing LOS guidance method for curve-following tracking control of underactuated USVs is urgently needed. Summary of the Invention

[0003] This application provides a vibration-reducing LOS guidance method for curve tracking control of underactuated unmanned surface vessels, which solves the problem that existing technologies are difficult to achieve accurate path tracking and stable navigation, and realizes precise motion control with anti-overshoot and vibration reduction for lateral tracking.

[0004] The first aspect of this application provides a vibration reduction LOS guidance method for curve tracking control of underactuated unmanned surface vessels (USVs). The method includes: obtaining the optimal path parameters of the USV based on an iterative approximation numerical solution method; incorporating the tracking error term and the velocity term of the tracking error into the drift angle estimation compensation; designing an adaptive vibration reduction LOS algorithm based on the drift angle estimation compensation and obtaining the desired heading angle of the USV by combining the optimal path parameters; constructing a sliding mode surface based on the desired heading angle, designing nonlinear sliding mode control, and generating a control torque; and performing desired heading tracking control on the USV based on the control torque.

[0005] Optionally, the optimal path parameters for the underactuated unmanned surface vessel (USV) are obtained using an iterative approximation numerical solution method. Specifically, this includes: constructing the first derivative of the curved path parameters over time using the lateral tracking error, longitudinal tracking error, and path coordinates as a function of the path parameters; combining the first derivative of the path parameters over time with the optimal path parameters from the previous sampling period, calculating the path parameters for the current iteration period using the first-order Euler method. The optimal path parameters are then determined based on the set maximum number of iterations.

[0006] Alternatively, the optimal path parameters can be calculated using the following formula: in, Indicates the update law parameters, This represents the optimal path parameters for the previous iteration cycle. Indicates longitudinal tracking error. Indicates lateral tracking error. and Represents the coordinates in the path-parallel coordinate system. and They represent right The first and second partial derivatives, and They represent For path parameters The first and second partial derivatives.

[0007] Optionally, based on drift angle estimation compensation, an adaptive vibration reduction LOS algorithm is designed, and the desired heading angle of the unmanned surface vessel is obtained by combining the optimal path parameters. Specifically, this includes: incorporating the tracking error term and the velocity term of the tracking error into the drift angle estimation compensation; based on drift angle estimation compensation, an adaptive vibration reduction LOS algorithm is designed, and the desired heading angle of the unmanned surface vessel is obtained by combining the optimal path parameters.

[0008] Alternatively, the desired heading angle can be calculated using the following formula: in, For the desired heading angle, For optimal path parameters, Forward sight distance, Rotate the azimuth angle of the path. This represents the estimated drift angle. The velocity term representing the estimated drift angle, and These are all parameters for estimating the drift angle. This represents the lateral tracking error in the tracking error term. The velocity term represents the lateral tracking error.

[0009] Optionally, the sliding surface is designed in conjunction with the desired heading angle, specifically including: calculating the heading error based on the difference between the actual heading angle and the desired heading angle; calculating the turning rate error based on the turning rate and the desired turning rate; and designing the sliding surface based on the heading error and the turning rate error.

[0010] Optionally, a nonlinear sliding mode controller is designed based on the desired heading angle and the sliding mode surface to construct the control torque. Specifically, this includes: calculating the moment of inertia based on the rotational inertia characteristics of the underactuated unmanned surface vessel during the bow-turning motion; and designing a nonlinear control law based on the moment of inertia and fixed parameters, combined with the sliding mode parameters in the sliding mode surface, and calculating the control torque.

[0011] Alternatively, the control torque can be calculated using the following formula: in, Indicates control torque. Indicates the moment of inertia. This represents the third-order bow rate parameter. This represents the first-order bow rate parameter. Indicates the turning speed. Indicates the desired turning rate. This represents the change in the expected turning rate over time. Indicates the turning rate error. Indicates a fixed parameter. and These are the sliding parameters in the sliding surface. This indicates the sliding surface.

[0012] A second aspect of this application provides a vibration reduction LOS guidance device for curve tracking control of underactuated unmanned surface vessels. The device includes a desired heading determination unit and a control torque calculation unit, wherein... The desired heading determination unit is used to obtain the optimal path parameters of the underactuated unmanned surface vessel (USV) based on the numerical solution method of iterative approximation. The tracking error term and the velocity term of the tracking error are introduced into the drift angle estimation compensation. Based on the drift angle estimation compensation, an adaptive vibration reduction LOS algorithm is designed and the desired heading angle of the USV is obtained by combining the optimal path parameters.

[0013] The control torque calculation unit is used to combine the desired heading angle to construct the sliding surface, design a nonlinear sliding controller, generate control torque, and perform desired heading tracking control on the underactuated unmanned surface vessel.

[0014] A third aspect of this application provides an electronic device including a processor, a memory, a user interface, and a network interface. The memory is used to store instructions, the user interface and the network interface are used to communicate with other devices, and the processor is used to execute the instructions stored in the memory to cause the electronic device to perform the method as described above.

[0015] A fourth aspect of this application provides a computer-readable storage medium storing a computer program, which is executed by a processor using the method described in any of the foregoing descriptions.

[0016] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages: 1. The optimal path parameters for the underactuated unmanned surface vessel (USV) are obtained using a numerical solution method based on iterative approximation. The lateral tracking error term and its velocity term are introduced into the drift angle estimation compensation. Based on the drift angle estimation compensation, an adaptive vibration reduction LOS algorithm is designed, and the desired heading angle of the USV is obtained by combining the optimal path parameters. Based on the desired heading angle, a sliding mode surface is constructed, and a nonlinear sliding mode controller is designed to generate control torque for the USV to perform desired heading tracking control. Under the influence of time-varying wind, waves, and current interference, rapid convergence of heading response and accurate convergence of lateral tracking are achieved. The velocity term of the lateral tracking error is used to effectively suppress tracking overshoot and oscillation, enabling the USV to maintain accurate tracking along a predetermined curved path.

[0017] 2. Using the lateral tracking error, longitudinal tracking error, and path coordinates as a function of path parameters, construct the first derivative of the curve path parameters over time. Using the first derivative of the path parameters over time and the optimal path parameters from the previous sampling period, calculate the path parameters for the current iteration period using the first-order Euler method, and set a maximum number of iterations to ensure that the path parameters converge within a finite number of iterations to a range that can stably constrain the longitudinal tracking error and be used for subsequent guidance and control.

[0018] 3. Based on the moment of inertia and fixed parameters, and combined with the sliding parameters in the sliding surface, a nonlinear sliding controller is designed to generate a control torque that can compensate for the nonlinear dynamics of the bow and enhance the ability to suppress model uncertainties and external disturbances, thereby achieving fast and accurate tracking of the desired heading angle. Attached Figure Description

[0019] Figure 1 This is a flowchart illustrating a vibration reduction LOS guidance method for curve tracking control of underactuated unmanned surface vessels provided in an embodiment of this application. Figure 2 This is a schematic diagram of a LOS guidance principle provided in an embodiment of this application; Figure 3This is a schematic diagram of an optimal path parameter iteration process provided in an embodiment of this application; Figure 4 This is a schematic diagram of the guidance and motion control principle of an underactuated unmanned surface vessel provided in an embodiment of this application; Figure 5 This is a schematic diagram of a curve path tracing provided in an embodiment of this application; Figure 6 This is a schematic diagram of optimal path parameters and longitudinal error provided in an embodiment of this application; Figure 7 This is a schematic diagram illustrating the tracking effect of a bow guidance law proposed in an embodiment of this application; Figure 8 This is a schematic diagram illustrating the control effect of a sliding mode heading controller proposed in an embodiment of this application; Figure 9 This is a schematic diagram comparing the results of different guidance methods provided in an embodiment of this application; Figure 10 This is a schematic diagram of a vibration reduction LOS guidance device for curve tracking control of underactuated unmanned surface vessels provided in an embodiment of this application. Figure 11 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application.

[0020] Explanation of reference numerals in the attached figures: 101, Desired heading determination unit; 102, Control torque calculation unit; 1101, Processor; 1102, Communication bus; 1103, User interface; 1104, Network interface; 1105, Memory. Detailed Implementation

[0021] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0022] The terminology used in the following embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to include the plural expressions as well, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this application refers to and includes any or all possible combinations of one or more of the listed items.

[0023] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature, and in the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0024] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0025] Please refer to Figure 1 The diagram shows a flowchart of a vibration reduction LOS guidance method for curve tracking control of underactuated unmanned surface vessels provided in this application embodiment. The flowchart mainly includes the following steps: S11 to S15.

[0026] Step S11: Obtain the optimal path parameters for the underactuated unmanned surface vessel based on the numerical solution method of iterative approximation.

[0027] Specifically, to address the coupling interference problem of longitudinal error on lateral tracking, an advanced discretized longitudinal error control strategy needs to be designed to achieve accurate convergence of the longitudinal error within each sampling period. This application innovatively employs a discrete iterative approximation method, effectively solving the shortcomings of traditional continuous control methods in error minimization. Secondly, regarding the critical issue of drift angle estimation accuracy, it is necessary to overcome the technical limitations of traditional integral line-of-sight guidance algorithms (ILOS / ALOS) and design a dynamic compensation mechanism to eliminate overshoot and vibration phenomena caused by integral time delay. The novel drift angle estimation method proposed in this application significantly improves the control accuracy and stability of tracking. Finally, to meet the requirement of rapid heading tracking, a high-performance heading tracking controller needs to be designed to achieve accurate and rapid tracking of the desired heading.

[0028] Therefore, in order to achieve the above effects, this application first needs to design the optimal path parameters of the underactuated unmanned surface vessel, which can be obtained based on the numerical solution method of iterative approximation.

[0029] In one possible implementation, step S11 further includes: constructing the first derivative of the curve path parameters over time using the lateral tracking error, the longitudinal tracking error, and the path coordinates as a function of the path parameters; calculating the path parameters for the current iteration period using the first derivative of the path parameters over time and the optimal path parameters from the previous sampling period using the first-order Euler method; and determining the optimal path parameters based on the set maximum number of iterations.

[0030] For details, please refer to Figure 2 , Figure 2This is a schematic diagram of a LOS guidance principle provided for an embodiment of this application. Figure 2 As shown, in this embodiment, line tracking is generally described in a path-parallel coordinate system. Let... Indicates curve path parameters, PP coordinate system origin By variables Confirmed. PP coordinate system. x The axis is tangent to the path, and the angle between it and the north direction is . According to the ship's position Position of the origin of the PP coordinate system and its rotation azimuth angle .

[0031] Based on the above path, the specific solution method for the optimal path parameters in this application is as follows: Please refer to... Figure 3 , Figure 3 This application provides a schematic diagram of a path parameter iteration process; as shown in the embodiments of this application. Figure 3 As shown, at the beginning of each closed-loop cycle, for Perform a cyclical numerical iteration. The iterative update law can be taken as ,in These are update law parameters; if we are judging longitudinal error... If the error is less than the preset error threshold or the maximum number of iterations is exceeded, stop the iteration and obtain the optimal path parameters. At the same time, a longitudinal error close to zero was obtained. If the stopping iteration condition is not met, the first and second derivatives of the position parameters are calculated to obtain the change of the curve path parameters over time. The above steps are repeated until the stopping iteration condition is met.

[0032] Please refer to Figure 4 , Figure 4 This application provides a schematic diagram of the guidance and motion control principle of an underactuated unmanned surface vessel (USV) as an embodiment of the present application. The application designs a vibration-reducing LOS guidance method for curve tracking control of underactuated USVs: First, multiple sensors, including GPS, are integrated into the sensing layer. An antenna array is used to synchronously acquire environmental information and pose data, providing the system with accurate... X b (Vertical) and Y b The system employs a (lateral) position reference; secondly, at the guidance layer, a tracking trajectory is generated based on geometric path planning, and the velocity-position coupling relationship is calculated in real time through multimodal information fusion; finally, at the control layer, the thrust distribution algorithm drives the thruster actuator to achieve closed-loop velocity-position regulation. Through the collaborative interaction of the sensor layer, guidance layer, and control layer, this system significantly improves the path tracking accuracy and motion stability of the unmanned surface vessel (USV) in complex sea conditions.

[0033] Step S12: Introduce the tracking error term and the tracking error velocity term into the drift angle estimation compensation.

[0034] Specifically, the tracking error in this application includes longitudinal error. and lateral error Longitudinal error and lateral error The calculation method is as follows: Expanding and differentiating the above equation, we can obtain the longitudinal error. speed term and lateral error speed term Among them, the path rotation azimuth angle , and , Represents the origin of the PP coordinate system Along x The speed of the shaft, Indicates the speed of the ship. It's a drift angle. This represents the lateral velocity component of the unmanned surface vessel in the lateral direction of the ship's coordinate system. This represents the longitudinal velocity component of the unmanned surface vessel in the bow direction of the hull coordinate system.

[0035] Specifically, the drift angle estimation uses the drift angle update law in the following formula: The above formula successfully incorporates the tracking error term and the velocity term of the tracking error into the drift angle estimation compensation.

[0036] Step S13: The adaptive vibration reduction LOS algorithm is adopted and the drift angle estimation compensation is used to obtain the desired heading angle of the driving unmanned surface vessel by combining the optimal path parameters.

[0037] Specifically, this application designs a control method for tracking underactuated unmanned surface vessels (USVs): First, an improved adaptive line-of-sight guidance algorithm is proposed at the kinematic guidance layer. An iterative approximation method is introduced to obtain the optimal path parameters, minimizing the longitudinal tracking error. The tracking error velocity term is dynamically integrated into the drift angle estimation process, effectively suppressing overshoot and chattering phenomena caused by traditional pure integral actions. At the dynamic control layer, an adaptive sliding mode heading controller is designed. Through the dynamic characteristics of the sliding surface and an adaptive gain adjustment mechanism, accurate and rapid tracking of the desired heading is achieved, significantly improving the path tracking performance of the USV in complex sea conditions. The iterative equation for the optimal path parameters is: in, Indicates the update law parameters, This represents the optimal path parameters for the previous iteration cycle. Indicates longitudinal tracking error. Indicates lateral tracking error. and Represents the coordinates in the path-parallel coordinate system. and They represent right The first and second partial derivatives, and They represent For path parameters The first and second partial derivatives.

[0038] In one possible implementation, step S13 further includes: calculating a drift angle estimate based on drift angle estimation compensation, and calculating a path rotation azimuth angle based on optimal path parameters; combining the forward-looking distance of the driving unmanned surface vessel, and based on the drift angle estimate and path rotation; obtaining the desired heading angle using the following formula: in, For the desired heading angle, For optimal path parameters, Forward sight distance, Rotate the azimuth angle of the path. This represents the estimated drift angle. The velocity term representing the estimated drift angle, and These are all parameters for estimating the drift angle. This represents the lateral tracking error in the tracking error term. The velocity term represents the lateral tracking error.

[0039] Specifically, It is the forward sight distance, indicating the ship's position. Projection point and foresight point in PP reference frame The distance between them can generally be taken as several times the total length of the ship.

[0040] Step S14: Combine the desired heading angle to construct the sliding surface, design a nonlinear sliding controller, and calculate the control torque.

[0041] Specifically, the sliding surface is constructed as follows: the heading error is calculated based on the difference between the actual heading angle and the desired heading angle; the turning rate error is calculated based on the turning rate and the desired turning rate; and the sliding surface is designed based on the heading error and the turning rate error. The calculation formula is expressed as follows:

[0042] in, Indicates the actual heading. Indicates heading error. Indicates the turning speed. Indicates the desired turning rate. This indicates the turning rate error.

[0043] The control torque is calculated as follows: The moment of inertia is constructed based on the rotational inertia characteristics of the underactuated unmanned surface vessel during its bow-turning motion; the control torque is then constructed based on the moment of inertia and fixed parameters, combined with the sliding mode parameters in the sliding surface. The calculation formula is expressed as follows:

[0044] in, Indicates control torque. Indicates the moment of inertia. This represents the third-order bow rate parameter. This represents the first-order bow rate parameter. Indicates the turning speed. Indicates the desired turning rate. This represents the change in the expected turning rate over time. Indicates the turning rate error. Indicates a fixed parameter. and These are the sliding parameters in the sliding surface. This indicates the sliding surface.

[0045] In a specific embodiment, traditional LOS guidance, ILOS guidance, ALOS guidance, and the proposed guidance law are applied to an underactuated unmanned surface vessel in a simulation environment. The effectiveness of the proposed guidance law is verified by comparing and analyzing different guidance strategies. First, four path points are set to generate an S-shaped curve path, as shown in the reference. Figure 5 , Figure 5This is a schematic diagram of curve path generation provided in an embodiment of this application. To comprehensively evaluate the control performance of the unmanned surface vessel (USV) in a time-varying environment, the initial speed of the USV is first set to 0.3 m / s to simulate typical cruise conditions. Secondly, to simulate complex disturbances in a real marine environment, a time-varying wind and wave load with a direction of 70° is applied to the system, the amplitude of which varies according to a sine law, and the time update law is set to 0.03 (i.e., a complete disturbance cycle is completed every 33.3 seconds). At the same time, a constant current velocity disturbance of 0.05 m / s is also superimposed to verify the robust performance of the system under combined disturbance conditions.

[0046] Please refer to the test results. Figure 6 , Figure 6 This is a schematic diagram illustrating the fitting of path parameters and longitudinal error in an embodiment of this application. Figure 6 Path parameters are displayed The update and corresponding changes in longitudinal error. During the time period, This indicates that the unmanned surface vessel has not yet entered the predetermined path. After 110 seconds, the path point coordinates are input within the iteration cycle, and calculations are performed first. The update law is then used to calculate the longitudinal error. This ensures that its size is always kept within the set acceptable threshold.

[0047] Figure 7 This is a schematic diagram illustrating the tracking effect of a guidance law proposed in an embodiment of this application, showing the first-order guidance for drift angle estimation. Introducing the velocity term of the tracking error into the calculation effectively suppresses the overshoot and oscillation phenomena of the tracking error.

[0048] Figure 8 This is a schematic diagram illustrating the control effect of a sliding mode heading controller proposed in an embodiment of this application, showing the converged heading tracking error. Convergence time It is evident that the sliding mode heading controller tracks the heading accurately and quickly.

[0049] Figure 9 This is a comparative schematic diagram illustrating the effect of guidance provided in an embodiment of this application. Figure 9The performance of LOS guidance, ILOS guidance, ALOS guidance, and the guidance method proposed in this application are compared under a sliding mode bow controller. It can be seen that ILOS and ALOS guidance, due to their pure integral action, exhibit time-delay in drift angle estimation, as well as overshoot and oscillation, ultimately leading to unsatisfactory tracking performance. Traditional LOS guidance, by ignoring the influence of drift angle, suffers from significant tracking errors. At each turning point, the proposed guidance method still tracks the preset path well; in contrast, the tracking errors of other methods fluctuate significantly, indicating that the proposed guidance law has excellent curve-following tracking performance.

[0050] In summary, a comparison of the experimental data clearly shows that: Figure 7 The tracking effect of the vibration reduction LOS guidance law proposed in this application is demonstrated. By innovatively introducing the tracking error velocity term in the calculation of the first derivative of drift angle estimation, the overshoot and oscillation phenomena that are common in traditional methods are effectively suppressed, and the smoothness and stability of path tracking are significantly improved. Figure 8 The bow tracking results demonstrate that the designed adaptive sliding mode bow controller achieves fast convergence and accurate tracking, fully validating the controller's dynamic performance and steady-state accuracy. In particular, Figure 9 The comparative experiments of multiple guidance algorithms clearly demonstrate that: traditional LOS guidance suffers from significant tracking errors due to neglecting the influence of drift angle; while ILOS and ALOS guidance consider drift angle estimation compensation, they suffer from overshoot and oscillations due to integral time delay; however, the guidance method proposed in this application maintains excellent tracking performance even when passing through various turning points, and its tracking error fluctuation amplitude is reduced compared to other methods, fully demonstrating the robustness and adaptability of the proposed guidance law under complex curved paths. These experimental results collectively verify the significant advantages of this scheme in improving the path tracking performance of unmanned surface vessels.

[0051] Step S15: Perform desired heading tracking on the underactuated unmanned surface vessel based on the control torque.

[0052] Specifically, addressing the longitudinal error convergence problem in unmanned surface vessel (USV) path tracking, this application proposes a numerical optimization algorithm based on iterative approximation. By setting a maximum iteration count constraint, the longitudinal tracking error is stably converged to a preset limit while ensuring computational efficiency. Secondly, to improve lateral tracking accuracy, an innovative vibration-damping LOS guidance law is designed. By synchronously introducing the tracking error and its velocity term, real-time compensation for the lateral error is achieved, and high-precision desired heading commands are generated by combining optimal path parameters. Thirdly, for heading tracking control, a sliding mode controller with adaptive gain adjustment is developed. By embedding the desired heading into the sliding mode surface design process and optimizing the control torque generation mechanism, rapid and accurate tracking of the desired heading is achieved.

[0053] Please refer to Figure 10 This document illustrates a schematic diagram of a vibration reduction LOS guidance device for curve tracking control of underactuated unmanned surface vessels, provided in an embodiment of this application. The device includes a desired heading determination unit 101 and a control torque calculation unit 102. The desired heading determination unit 101 is used to obtain the optimal path parameters corresponding to the underactuated unmanned surface vessel based on the numerical solution method of iterative approximation; the tracking error term and the velocity term of the tracking error term are introduced into the drift angle estimation compensation; based on the drift angle estimation compensation, an adaptive vibration reduction LOS algorithm is designed, and the desired heading angle of the driven unmanned surface vessel is obtained by combining the optimal path parameters.

[0054] The control torque calculation unit 102 is used to design the sliding surface in combination with the desired heading angle, and to construct the control torque through the desired heading angle and the sliding surface; and to perform desired heading tracking on the underactuated unmanned surface vessel based on the control torque.

[0055] In one possible implementation, the heading determination unit 101 is expected to obtain the optimal path parameters for the underactuated unmanned surface vessel (USV) using a numerical solution method based on iterative approximation. Specifically, this includes: constructing the first derivative of the curved path parameters over time using the lateral tracking error, longitudinal tracking error, and path coordinates as a function of the path parameters; calculating the path parameters for the current iteration period using the first derivative of the path parameters over time and the optimal path parameters from the previous sampling period, employing the first-order Euler method; and determining the optimal path parameters based on a set maximum number of iterations.

[0056] In one possible implementation, the desired heading determination unit 101 is used to design an adaptive vibration reduction LOS algorithm based on drift angle estimation compensation. The desired heading angle of the driving unmanned surface vessel is obtained by combining the optimal path parameters. Specifically, it includes: calculating the drift angle estimate based on drift angle estimation compensation; calculating the path rotation azimuth using the optimal path parameters; and obtaining the desired heading angle by combining the forward look-ahead distance of the driving unmanned surface vessel and the path rotation azimuth.

[0057] In one possible implementation, the desired heading determination unit 101 is used to calculate the desired heading angle using the following formula: in, For the desired heading angle, For optimal path parameters, Forward sight distance, Rotate the azimuth angle of the path. This represents the estimated drift angle. The velocity term representing the estimated drift angle, and These are all parameters for estimating the drift angle. This represents the lateral tracking error in the tracking error term. The velocity term represents the lateral tracking error.

[0058] In one possible implementation, the control torque calculation unit 102 is used to design the sliding surface in conjunction with the desired heading angle, specifically including: calculating the heading error based on the difference between the actual heading angle and the desired heading angle; calculating the turning rate error based on the turning rate and the desired turning rate; and designing the sliding surface based on the heading error and the turning rate error.

[0059] In one possible implementation, the control torque calculation unit 102 is used to construct the control torque by means of the desired heading angle and the sliding surface, specifically including: constructing the moment of inertia based on the rotational inertia characteristics of the underactuated unmanned surface vessel in the bow-turning motion; and constructing the control torque based on the moment of inertia and fixed parameters, combined with the sliding parameters in the sliding surface.

[0060] In one possible implementation, the control torque calculation unit 102 is used to calculate the control torque using the following formula: in, Indicates control torque. Indicates the moment of inertia. This represents the third-order bow rate parameter. This represents the first-order bow rate parameter. Indicates the turning speed. Indicates the desired turning rate. This represents the change in the expected turning rate over time. Indicates the turning rate error. Indicates a fixed parameter. and These are the sliding parameters in the sliding surface. This indicates the sliding surface.

[0061] It should be noted that the above embodiments of the apparatus are only illustrated by the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the apparatus and method embodiments provided in the above embodiments belong to the same concept, and the specific implementation process can be found in the method embodiments, which will not be repeated here.

[0062] This application also provides an electronic device. (See reference...) Figure 11 , Figure 11 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. The electronic device may include: at least one processor 1101, at least one communication bus 1102, a user interface 1103, at least one network interface 1104, and a memory 1105.

[0063] The communication bus 1102 is used to realize the connection and communication between these components.

[0064] The user interface 1103 may include a display screen and a camera. Optionally, the user interface 1103 may also include a standard wired interface and a wireless interface.

[0065] The network interface 1104 may optionally include a standard wired interface or a wireless interface (such as a Wi-Fi interface).

[0066] The processor 1101 may include one or more processing cores. The processor 1101 connects to various parts of the server using various interfaces and lines, and performs various server functions and processes data by running or executing instructions, programs, code sets, or instruction sets stored in memory 1105, and by calling data stored in memory 1105. Optionally, the processor 1101 may be implemented using at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor 1101 may integrate one or a combination of several of the following: Central Processing Unit (CPU), Graphics Processing Unit (GPU), and modem. The CPU primarily handles the operating system, user interface, and applications; the GPU is responsible for rendering and drawing the content required for display; and the modem handles wireless communication. It is understood that the modem may also not be integrated into the processor 1101 and may be implemented as a separate chip.

[0067] The memory 1105 may include random access memory (RAM) or read-only memory. Optionally, the memory 1105 may include a non-transitory computer-readable storage medium. The memory 1105 can be used to store instructions, programs, code, code sets, or instruction sets. The memory 1105 may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function (such as touch function, sound playback function, image playback function, etc.), instructions for implementing the above-described method embodiments, etc.; the data storage area may store data involved in the above-described method embodiments, etc. Optionally, the memory 1105 may also be at least one storage device located remotely from the aforementioned processor 1101. (Refer to...) Figure 11 The memory 1105, which serves as a computer storage medium, may include an operating system, a network communication module, a user interface module, and application programs.

[0068] exist Figure 11 In the illustrated electronic device, the user interface 1103 is primarily used to provide an input interface for the user and acquire user input data; while the processor 1101 can be used to call the application program stored in the memory 1105. When executed by one or more processors 1101, the electronic device performs one or more of the methods described in the above embodiments. It should be noted that, for the foregoing method embodiments, for the sake of simplicity, they are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, because according to this application, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also understand that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0069] This application also provides a computer-readable storage medium storing instructions. When executed by one or more processors, these instructions cause an electronic device to perform one or more of the methods described in the above embodiments.

[0070] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0071] In the various embodiments provided in this application, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some service interface; the indirect coupling or communication connection between apparatuses or units may be electrical or other forms.

[0072] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0073] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0074] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage device (CMD). Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned memory includes various media capable of storing program code, such as USB flash drives, portable hard drives, magnetic disks, or optical disks.

[0075] The above description is merely an exemplary embodiment disclosed in this application and should not be construed as limiting the scope of this application. Any equivalent changes and modifications made in accordance with the teachings of this application shall still fall within the scope of this application.

[0076] This application is intended to cover any variations, uses, or adaptations disclosed herein that follow the general principles disclosed herein and include common knowledge or customary technical means in the art that are not described in this application.

Claims

1. A vibration reduction LOS guidance method for curve tracking control of an underactuated unmanned surface vehicle, characterized in that, The method comprises: An optimal path parameter of the under-actuated unmanned surface vehicle is obtained based on an iterative approximation numerical solution method; A tracking error term and a tracking error velocity term are introduced into drift angle estimation compensation; An adaptive damping LOS algorithm is designed based on the drift angle estimation compensation, and an expected heading angle of the unmanned surface vehicle is obtained by combining the optimal path parameter; A sliding mode surface is constructed in combination with the expected heading angle, a nonlinear sliding mode controller is designed, and a control moment is constructed; The under-actuated unmanned surface vehicle is subjected to expected heading tracking based on the control moment.

2. The method of claim 1, wherein, An optimal path parameter of the under-actuated unmanned surface vehicle is obtained based on an iterative approximation numerical solution method, specifically comprising: A first-order derivative of a curve path parameter with respect to time is constructed by using a lateral tracking error, a longitudinal tracking error, and path coordinate points that are functions of the path parameter; The first-order derivative of the path parameter with respect to time and an optimal path parameter in a previous sampling period are used to calculate the path parameter in a current iteration period by using a first-order Euler method, and the optimal path parameter is determined according to a set maximum number of iterations; The optimal path parameter is calculated in the current period by using an iterative method according to the following formula: wherein denotes the update law parameter, denotes the optimal path parameter of the previous iteration cycle, denotes the longitudinal tracking error, denotes the lateral tracking error, and denotes the coordinates in the path parallel coordinate system, and denote the first and second order partial derivatives of respectively, and denote the first and second order partial derivatives of the path parameter respectively; denotes the velocity term of the path parameter .

3. The method of claim 1, wherein, An adaptive damping LOS algorithm is designed based on the drift angle estimation compensation, and an expected heading angle of the unmanned surface vehicle is obtained by combining the optimal path parameter, specifically comprising: A drift angle estimation value is calculated based on the drift angle estimation compensation method, and a path rotation azimuth angle is calculated based on the optimal path parameter; The expected heading angle is obtained by a LOS guidance algorithm based on a set under-actuated unmanned surface vehicle forward-looking distance parameter, the drift angle estimation value, and the path rotation azimuth angle.

4. The method of claim 3, wherein, The expected heading angle is calculated by the following formula: wherein is the desired heading angle, is the optimal path parameter, is the look-ahead distance, is the path rotation azimuth angle, denotes the drift angle estimate, denotes the velocity term of the drift angle estimate, and are drift angle estimation parameters, denotes the lateral tracking error in the tracking error term, denotes the velocity term of the lateral tracking error.

5. The method of claim 1, wherein, The sliding mode surface is designed in combination with the expected heading angle, specifically comprising: A heading error is calculated based on a difference between an actual heading angle and the expected heading angle; A turning heading rate error is calculated based on a turning heading rate and an expected turning heading rate; The sliding mode surface is designed based on the heading error and the turning heading rate error.

6. The method of claim 5, wherein, The control moment is constructed by the expected heading angle and the sliding mode surface, specifically comprising: A moment of inertia is determined based on a moment of inertia characteristic of the under-actuated unmanned surface vehicle in turning heading motion; A nonlinear sliding mode controller is designed based on the moment of inertia and a fixed parameter in combination with a sliding mode parameter in the sliding mode surface, so as to generate the control moment.

7. The method of claim 6, wherein, The control moment is calculated by the following formula: wherein denotes the control torque, denotes the moment of inertia, denotes a third order yaw rate parameter, denotes a first order yaw rate parameter, denotes the yaw rate, denotes the desired yaw rate, denotes a change of the desired yaw rate over time, denotes the yaw rate error, denotes the fixed parameter, and is the sliding mode parameter in the sliding surface, denotes the sliding surface.

8. A vibration reduction LOS guidance device for curve tracking control of an underactuated unmanned surface vehicle, characterized in that, The device comprises an expected heading determination unit and a control moment calculation unit, wherein, The expected heading determination unit is configured to obtain an optimal path parameter of the under-actuated unmanned surface vehicle based on an iterative approximation numerical solution method, introduce a tracking error term and a velocity term of the tracking error term into drift angle estimation compensation, and design an adaptive damping LOS algorithm to obtain an expected heading angle of the unmanned surface vehicle by combining the optimal path parameter. The control torque calculation unit is configured to design a sliding mode surface in combination with the desired heading angle, design a nonlinear sliding mode controller based on the desired heading angle and the sliding mode surface, and construct a control torque; and track the desired heading of the underactuated unmanned surface vehicle based on the control torque.

9. An electronic device, comprising: The electronic device comprises a processor, a communication bus, a user interface, a network interface, and a memory, the memory is configured to store instructions, the user interface and the network interface are configured to communicate with other devices, and the processor is configured to execute the instructions stored in the memory to enable the electronic device to perform the method of any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium stores instructions which, when executed, perform the method of any one of claims 1 to 7.

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