Synchronous trajectory planning and execution control method for depth tracking of under-actuated underwater vehicle

Abstract

The invention belongs to the field of underwater robot control, and particularly discloses a synchronous trajectory planning and execution control method for depth tracking of an underwater vehicle, and the method comprises the steps: converting a depth tracking error into an expected trim angle through designing a self-adaptive sight angle guidance law, and compensating the kinematics interference caused by an unknown attack angle; converting the expected trim angle tracking error and the speed constraint thereof into expected trim angle acceleration; in controller design, external environment force and nonlinear dynamic coupling disturbance are estimated in real time according to expected trim angle acceleration and state feedback information, a control law is designed in combination with the expected trim angle acceleration, and rudder angle output of the underwater vehicle is calculated; and finally, the control algorithm is deployed on a boat-mounted controller, and the angle of the elevator is controlled in real time through feedback information of a sensor. By constructing a control framework of guidance, planning and control, the problem of insufficient control precision of traditional control in a complex environment is solved, and the depth tracking precision and engineering applicability of the underwater vehicle are remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of underwater vehicle control, and in particular to a synchronous trajectory planning and execution control method for depth tracking of underwater vehicles. BACKGROUND

[0002] Autonomous underwater vehicles (AUVs) are widely used in ocean exploration, scientific research, environmental monitoring, and military applications. With the advancement of technology, the design and functionality of underwater vehicles continue to evolve, enabling them to perform tasks in complex marine environments such as seabed topography mapping, marine life observation, and pollution monitoring. Compared to traditional manned submersibles, underwater vehicles offer higher safety and flexibility, allowing them to operate in deep water for extended periods without the limitations of human diving. Furthermore, as global attention to marine resources and environmental protection increases, the importance of underwater vehicles in marine scientific research and resource development is increasingly highlighted. However, achieving high-precision depth tracking control of underwater vehicles has become a key technical challenge that needs to be addressed. The dynamic characteristics of underwater vehicles exhibit strong coupling and high nonlinearity, making it difficult for traditional control methods to effectively handle their complex motion patterns. In addition, the variability of underwater environments, such as water flow, waves, temperature, and salinity changes, significantly affect the depth tracking ability of the vehicle. Furthermore, in practical operations, it is often difficult to obtain the hydrodynamic parameters of the vehicle, which can lead to significant differences between actual control effects and expectations, further reducing its depth tracking performance.

[0003] Chinese patent document CN118092482A, published (announced) on May 28, 2024, discloses an adaptive STSMC hierarchical control method for depth tracking of underwater vehicles. This document mainly designs an adaptive saturation compensator related to the dynamic control layer, which can better solve the problem of rudder angle saturation, improving the control performance and stability of underwater vehicles.

[0004] In addition, Chinese patent document CN118311862A, published (announced) on April 11, 2025, discloses a model-free adaptive control method for depth tracking of underactuated unmanned underwater vehicles. This document mainly estimates and compensates the attack angle and dynamic linearization residuals in real time, further improving the overall tracking performance. When facing external sudden disturbances, it has faster convergence speed, higher steady-state accuracy, and stronger anti-disturbance ability compared to classical control methods, while the steering is smooth and changes slowly, which can significantly reduce mechanical noise, reduce rudder fatigue damage, and prolong service life. SUMMARY The technical problem solved by the present application is to solve the problems in the background art, provide a synchronous trajectory planning and execution control method for underwater vehicle depth tracking, and solve the problem of complex control algorithm structure of underwater vehicles in complex interference environment when performing high-precision depth tracking operation.

[0005] To achieve the above object, in a first aspect, the present application provides a synchronous trajectory planning and execution control method for underwater vehicle depth tracking, comprising: Obtaining the expected depth control target and feedback state of the underwater vehicle; the state feedback includes depth feedback, speed feedback, pitch angle feedback and pitch angle speed feedback; Determining the depth error, designing an adaptive line-of-sight angle guidance algorithm, and obtaining the expected pitch angle of the underwater vehicle; Combining the feedback pitch angle and the expected pitch angle, determining the tracking error and tracking error speed of the pitch angle; combining the tracking error and error speed constraint information, implementing polynomial trajectory planning, and obtaining the expected pitch angle acceleration; According to the expected pitch angle acceleration and state feedback information, a nonlinear disturbance adaptive compensation estimation method is designed to compensate for external environmental forces and dynamic coupling disturbances.

[0006] A synchronous planning and execution controller with nonlinear disturbance adaptive compensation is used, combined with the above expected pitch angle acceleration and nonlinear disturbance compensation estimation, to obtain the rudder angle of the underwater vehicle.

[0007] It should be noted that the present application divides the depth tracking control of the underwater vehicle into a guidance layer, a planning layer and an execution layer. The guidance layer and the planning layer belong to the kinematic control level, and the execution layer belongs to the dynamic control level. The guidance layer mainly overcomes the under-actuated characteristics of the hull through the designed adaptive line-of-sight angle guidance law, and compensates for the kinematic disturbance caused by the unknown attack angle; the planning layer mainly implements polynomial trajectory planning combined with the tracking error and tracking error speed of the pitch angle, to obtain the expected pitch angle acceleration of the pitch angle; the execution layer estimates the external environmental forces and nonlinear dynamic coupling disturbances in real time according to the expected pitch angle acceleration and state feedback information, and calculates the rudder angle output of the underwater vehicle through the synchronous planning and execution controller according to the above nonlinear estimation and expected pitch angle acceleration. Through the design of the above three-layer control architecture, the problem of insufficient depth control precision in complex environment when facing the conventional single-loop control is solved.

[0008] It can be understood that, in the case that the stability of the guidance layer is ensured, the planning layer and the execution layer ensure the stability of the overall system. Specifically, the guidance layer inputs the calculated expected pitch angle into the planning layer according to the real-time depth error of the underwater vehicle, the planning layer inputs the expected pitch angle acceleration calculated according to the expected pitch angle into the execution layer, and the execution layer performs nonlinear compensation estimation and calculates the elevator angle according to the expected pitch angle acceleration information, and then adjusts its own attitude to track the expected pitch angle, so as to indirectly control the depth by controlling the pitch angle.

[0009] In a possible implementation, the adaptive line-of-sight angle guidance law comprises the following formula: ; wherein, denotes a guidance pitch angle provided by the guidance law, denotes an arctangent function, denotes a depth tracking error, , and Γ denote adaptive line-of-sight angle guidance law parameters, denotes an attack angle compensation term of the underwater vehicle, denotes a first-order derivative of , denotes a resultant velocity of the underwater vehicle on the depth plane.

[0010] In a possible implementation, the expected pitch angle acceleration of the pitch angle is obtained by solving the second-order derivative of the following polynomial trajectory planning: ; wherein, , , and are undetermined coefficients of the polynomial planning, is a polynomial planning time, which is uniquely determined by the following tracking error constraint condition: ; ; wherein, is defined as a pitch angle tracking error, and respectively denote a tracking error and a velocity at a current time ; and respectively denote an expected convergence error and a velocity at a future time .

[0011] In a possible implementation, the expected pitch angle acceleration under the polynomial trajectory planning is represented as: ; wherein, the second derivative of the polynomial at the current time is calculated. .

[0012] In a possible implementation, the nonlinear disturbance adaptive compensation estimation is: ; wherein, and denote the nonlinear disturbance in the current sampling period i and the last sampling period i -1 respectively; denote the parameters of the nonlinear disturbance estimation.

[0013] In a possible implementation, the expected control rudder angle control law of the synchronous planning and execution control method is: ; wherein, is a proportional parameter between the rudder angle and the acceleration.

[0014] In a second aspect, the application provides a synchronous trajectory planning and execution control system for depth tracking of an underwater vehicle, comprising: a state acquisition unit configured to acquire control targets and states of the underwater vehicle, including: expected depth, real-time depth, real-time speed, real-time trim angle, and real-time trim angle speed; a depth surface guidance unit configured to design an adaptive line-of-sight angle guidance law according to a depth error corresponding to the expected depth and the real-time depth, and calculate an expected trim angle of the underwater vehicle; a polynomial trajectory planning unit configured to perform an online trajectory planning task according to the depth error corresponding to the expected depth and the real-time depth and a speed error thereof, to obtain an expected trim angle acceleration; a nonlinear disturbance estimation unit configured to update an estimation of the nonlinear disturbance in real time according to the expected trim angle acceleration; a control rudder angle calculation unit configured to calculate a rudder angle output of the underwater vehicle in real time according to the expected trim angle acceleration.

[0015] a vehicle rudder angle adjustment unit configured to control an elevator of the underwater vehicle based on the rudder angle calculation value, so that the underwater vehicle navigates according to the expected depth.

[0016] In a third aspect, the present application discloses an electronic device, which comprises: at least one storage module configured to store program instructions; and at least one operation module configured to execute the program instructions stored in the storage module, wherein the operation module implements the method process of the first aspect or any of the optional embodiments of the first aspect when the stored program instructions are executed.

[0017] In a fourth aspect, the present application also provides a readable storage carrier, which has computer executable codes recorded thereon, and the codes, when processed by an operation module, trigger the operation module to execute the method steps defined in the first aspect or any of the possible embodiments of the first aspect.

[0018] In a fifth aspect, the present application further discloses a computer program product, which, when the instructions contained therein are executed by an operation module, enables the operation module to operate according to the method described in the first aspect or any of the possible embodiments of the first aspect.

[0019] It can be understood that the beneficial effects of the second aspect to the fifth aspect described above can be referred to the related description of the first aspect, and will not be repeated here.

[0020] Overall, compared with the prior art, the above technical solutions conceived by the present application have the following beneficial effects: The present application provides a synchronous trajectory planning and execution control method for depth tracking of underwater vehicles. The depth tracking system of the underwater vehicle is divided into a guidance layer, a planning layer and an execution layer. First, an adaptive line-of-sight angle guidance law is designed in the guidance layer to overcome the under-actuated characteristics, convert the depth tracking error into a desired pitch angle, and compensate for the kinematic disturbance caused by the unknown attack angle. Second, considering that the tracking of the desired pitch angle is affected by the nonlinear dynamics of the underwater vehicle, the desired pitch angle tracking error and its speed constraint are converted into the desired pitch angle acceleration in the planning layer. Then, in the control layer, the external environmental force and the nonlinear dynamics coupling disturbance are estimated in real time according to the desired pitch angle acceleration and the state feedback information, and a control law is designed in combination with the desired pitch angle acceleration to calculate the rudder angle output of the underwater vehicle. Finally, the above control algorithm is deployed on the on-board controller, and the elevator angle of the underwater vehicle is controlled by reading the real-time depth and attitude information fed back by the on-board sensors to execute the depth tracking task. Through the design of the above three-layer control architecture, the problem of insufficient depth control precision in the face of complex environment in the conventional single-loop control is solved. The three layers are tightly coupled, and the control architecture is simple and convenient for engineering practice and application. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced as follows.

[0022] Figure 1The flow chart of the synchronous trajectory planning and execution control method for depth tracking of the underwater vehicle is provided for the embodiments of the present application.

[0023] Figure 2 The underwater vehicle coordinate system and state definition schematic diagram is provided for the embodiments of the present application.

[0024] Figure 3 The flow chart of the synchronous trajectory planning and execution control method for depth tracking of the underwater vehicle is provided for the embodiments of the present application.

[0025] Figure 4 The synchronous trajectory planning and execution control test verification scene schematic diagram for depth tracking of the underwater vehicle is provided for the embodiments of the present application.

[0026] Figure 5 The underwater vehicle attack angle estimation and nonlinear disturbance estimation is provided for the embodiments of the present application.

[0027] Figure 6 The elevator angle curve diagram of the underwater vehicle is provided for the embodiments of the present application.

[0028] Figure 7 The depth tracking control curve diagram of the underwater vehicle is provided for the embodiments of the present application.

[0029] Figure 8 The pitch angle tracking control curve diagram of the underwater vehicle is provided for the embodiments of the present application.

[0030] Figure 9 The system architecture diagram of the synchronous trajectory planning and execution control for depth tracking of the underwater vehicle is provided for the embodiments of the present application.

[0031] Figure 10 The architecture diagram of the electronic system is provided for the embodiments of the present application. DETAILED DESCRIPTION

[0032] In order to more clearly illustrate the purpose, technical scheme and beneficial effects of the present application, the present application will be further described in detail in conjunction with the drawings and specific implementation manners. It should be particularly pointed out that the specific implementation examples described below are only used to illustrate the technical content of the present application, and do not constitute a limitation on the protection scope of the present application.

[0033] Regarding the term explanation: in the present application, "and / or" is used to describe the relationship between the associated objects, which covers three possible cases: for example, "A and / or B" can represent the case of only A, the case of A and B existing at the same time, or the case of only B; the symbol " / " represents the "or" relationship between the associated objects, such as "A / B" refers to A or B.

[0034] Regarding the embodiment description: The terms "exemplary", "for example", etc. appearing in the present application are only used to illustrate the technical solutions through specific cases. It should be particularly emphasized that any embodiment or design scheme marked as "exemplary" or "for example" should not be understood as more advantageous than other schemes. Such expressions are only used to present the technical concept more intuitively.

[0035] Embodiment 1: Firstly, an adaptive line-of-sight angle guidance law is designed to overcome the underactuated characteristics of the underwater vehicle, convert the depth tracking error into the desired pitch angle, and compensate for the kinematic disturbance caused by the unknown attack angle; secondly, considering that the desired pitch angle tracking is affected by the nonlinear dynamics characteristics of the underwater vehicle, the desired pitch angle tracking error and its speed constraint are converted into the desired pitch angle acceleration; then, based on the desired pitch angle acceleration and state feedback information, the external environmental force and the nonlinear dynamics coupling disturbance are estimated in real time, and a control law is designed combined with the desired pitch angle acceleration to calculate the rudder angle output command of the underwater vehicle; finally, the above control algorithm is deployed to the on-board controller, and by reading the depth and attitude information fed back by the on-board sensors in real time, the rudder angle of the underwater vehicle is accurately controlled to realize the depth tracking task execution.

[0036] The present application aims to solve the multiple control challenges faced by underwater vehicles in complex operating environments. Firstly, an adaptive depth tracking control method is developed to ensure smooth operation of the vehicle in dynamic environments in the face of system model uncertainty and time-varying disturbances. Secondly, a robust control system with disturbance estimation and compensation function is designed to effectively handle model dynamics perturbation and unknown environmental disturbances, while suppressing high-frequency oscillation of the actuator; finally, the practical application value of the method is verified through experiments.

[0037] Figure 1 The flowchart of the synchronous trajectory planning and execution control method for underwater vehicle depth tracking provided by the embodiments of the present application is shown in FIG. 1. As shown in FIG. 1, the method comprises the following steps: Figure 1 S101, an adaptive line-of-sight angle guidance algorithm is designed to estimate the attack angle of the underwater vehicle in real time to calculate the desired pitch angle of the underwater vehicle; S102, the desired pitch angle tracking error and its speed constraint are converted into the desired pitch angle acceleration; S103, based on the desired pitch angle acceleration and state feedback information, the external environmental force and the nonlinear dynamics coupling disturbance are estimated in real time; S104, a control law is designed using the desired pitch angle acceleration and disturbance estimation to calculate the rudder angle output command of the underwater vehicle.

[0038] Figure 2 ​An underwater vehicle coordinate system and state definition diagram provided for the embodiments of the present application, and main parameters of the system are shown in Table 1.

[0039]

[0040] Figure 3 A synchronous trajectory planning and execution control flow diagram for depth tracking of an underwater vehicle provided for the embodiments of the present application. Figure 3 In the depth tracking control system of the underwater vehicle, the desired depth, the measured feedback depth, the measured feedback pitch angle, the pitch angle velocity. Wherein the desired depth is obtained by subtracting the real-time depth from the desired depth, and the depth error is obtained. The depth error is taken as an input of the guidance law to calculate the desired pitch angle , and then the feedback pitch angle

[0041] is subtracted to calculate the elevator control instruction in the pitch angle controller. Specifically, the present application designs a synchronous trajectory planning and execution control method for depth tracking of an underwater vehicle: the method divides the depth tracking control system of the underwater vehicle into a guidance layer, a planning layer and an execution layer. First, an adaptive line-of-sight angle guidance law is designed in the guidance layer to overcome the under-actuated characteristics, convert the depth tracking error into a desired pitch angle, and compensate for the kinematic disturbance caused by unknown attack angle; second, considering that the tracking of the desired pitch angle is affected by the nonlinear dynamics of the underwater vehicle, the desired pitch angle tracking error and its velocity constraint are converted into a desired pitch angle acceleration in the planning layer; then, in the control layer, the external environmental force and the nonlinear dynamics coupling disturbance are estimated in real time according to the desired pitch angle acceleration and the state feedback information, and a controller is designed in combination with the desired pitch angle acceleration to calculate the rudder angle output of the underwater vehicle.

[0042] The adaptive line-of-sight angle guidance algorithm is as follows: ; Wherein, represents the desired pitch angle, represents the arctangent function, represents the depth tracking error, , and Γ represent the adaptive line-of-sight angle guidance law parameters, represents the attack angle compensation term of the underwater vehicle, represents a first-order differential, represents the resultant velocity of the underwater vehicle on the depth surface.

[0043] The desired pitch acceleration of the trajectory planning is: ; Wherein, The second derivative of the polynomial at the current time is calculated. , , and are the undetermined coefficients of the polynomial planning, is the polynomial planning time, which is uniquely determined by the following tracking error constraint condition: ; ; Wherein, is defined as the pitch angle tracking error, and represent the tracking error and speed at the current time ; and represent the desired convergence error and speed at the future time .

[0044] The controller is: ; Wherein, is the proportional parameter between the rudder angle and the acceleration, represents the nonlinear disturbance summation estimate in the current sampling period i .

[0045] The nonlinear disturbance adaptive compensation estimate is: ; Wherein, and represent the nonlinear disturbance in the current sampling period i and the last sampling period i -1 respectively; represents the parameter of the nonlinear disturbance estimate.

[0046] It can be understood that the various calculation parameters involved in the present application can be reasonably selected by the skilled person according to the actual needs through experience or simulation means to ensure that the system reaches the optimal operating state. It needs to be emphasized that the present application does not limit the numerical range of any specific parameter. Among them, the system performance mainly reflects: 1) In the depth control dimension, the degree of agreement between the actual diving depth and the set target value; 2) In the attitude adjustment dimension, the matching accuracy of the actual longitudinal angle of the carrier and the target angle.

[0047] In a specific implementation case, the performance of the method is verified by designing a pool test, and the test arrangement is shown in Figure 4 . The test focuses on the dynamic response characteristics of the underwater vehicle in the depth control task. To highlight the advantages of the method, the integral line-of-sight guidance (ILOS) combined with the PID control scheme is selected as the comparison benchmark. During the test, the mass mutation condition is simulated by accurately regulating the water suction and discharge device of the sealed cabin to build a dynamic disturbance scene that conforms to the actual operation environment. Figure 5 The test curve clearly shows the change law of the attack angle calculated by the guidance algorithm in real time and the dynamic estimation process of the nonlinear disturbance, effectively verifying the reliability of the disturbance simulation mechanism and providing reliable data support for subsequent scheme verification.

[0048] The test data analysis shows that there is a significant difference in the response characteristics of the actuators of the two control strategies. As shown in Figure 6 , in the rudder angle output comparison, although there is a small high-frequency oscillation phenomenon in the proposed scheme, this slight fluctuation actually enhances the anti-interference ability of the system, enabling it to effectively cope with sudden disturbances. This advantage is further verified in the comparison test results of Figure 7 and Figure 8 , which are specifically manifested in the significant improvement in the stability and recovery performance of the system under disturbance conditions.

[0049] The test data comparison and analysis are shown in Figure 7 , which shows the depth maintenance ability of different control strategies under dynamic disturbance conditions. Observing the curve characteristics, it can be found that the traditional ILOS-PID control scheme shows obvious control instability under the action of mass mutation disturbance, and the depth peak deviation in the transient response stage reaches 0.4 meters. In contrast, the control algorithm designed in this paper only produces a depth instantaneous deviation of 0.2 meters under the same disturbance conditions. After the system recovers to stable operation, the accuracy difference between the two control schemes is more significant: the continuous steady-state error of the traditional method maintains at about 0.2 meters, while the error amplitude of the proposed scheme is reduced to below 0.05 meters. Further analysis of the attitude control performance, Figure 8 the pitch angle tracking curve shows that the proposed method also exhibits superiority in the angle control dimension. By comparing the coincidence of the two response curves, it can be directly observed that the following accuracy of the target pitch angle of the proposed scheme is significantly better than that of the traditional method, verifying the comprehensive performance advantage of the proposed control strategy.

[0050] In summary, there are significant differences in key performance indicators between different control algorithms. When facing the influence of sudden disturbance, the traditional ILOS-PID controller produces a significant transient deviation in the depth control dimension ( Figure 7 ); on the other hand, in the attitude control dimension ( Figure 8) sharp increase of the tracking error of the pitch angle. In contrast, the new control strategy adopted by the present solution effectively enhances the anti-interference ability of the system by introducing controllable high-frequency small amplitude rudder angle adjustment ( Figure 6 ). This design makes the system in the face of disturbance: depth control accuracy ( Figure 7 ) is significantly improved; the attitude tracking error ( Figure 8 ) is greatly reduced. The test data fully verify the double advantages of the proposed method in improving the dynamic performance and steady-state accuracy of the system.

[0051] Therefore, it can be understood that under the influence of transient disturbance, the two control algorithms show completely different characteristics. The traditional ILOS-PID scheme lacks effective anti-interference mechanism, resulting in a significant reduction in control efficiency. This phenomenon is directly reflected in the system response, which is manifested as a significant deterioration in tracking accuracy.

[0052] Embodiment 2: Figure 9 The structural diagram of the synchronous trajectory planning and execution control system for depth tracking of the underwater vehicle provided by the embodiment of the present application; as shown in Figure 9 , comprising: The expected pitch angle determination unit 910 is configured to estimate the attack angle of the underwater vehicle in real time by using the adaptive line-of-sight angle guidance algorithm, so as to obtain the expected pitch angle of the underwater vehicle. The unknown disturbance estimation unit 920 is configured to estimate the external environmental force and the nonlinear dynamic coupling disturbance in real time by using the expected pitch angle acceleration and state feedback information. The control rudder angle calculation unit 930 is configured to design a controller by using the expected pitch angle acceleration and disturbance estimation, and calculate the rudder angle output of the underwater vehicle.

[0053] It should be understood that the above system is used to execute the method in the above embodiment, the corresponding program unit in the system, the implementation principle and technical effect are similar to the description in the above method, and the working process of the system can refer to the corresponding process in the above method, which will not be described here.

[0054] Based on the method in the above embodiment, an electronic equipment implementation scheme proposed by the present application is shown in Figure 10 , which includes the following core components: a central processing unit 1010, a data communication module 1020, a storage unit 1030, and a system bus 1040. Each functional module realizes data interaction and instruction transmission through the system bus 1040. Among them, the central processing unit 1010 can completely realize the whole control process of the technical scheme described above by reading the program instructions in the storage unit 1030.

[0055] Moreover, the technical solution is implemented in the form of software, and the program instructions in the storage unit 1030 can be packaged as standardized function modules. When these modules are commercially applied as independent products, they can be solidified in a computer readable storage carrier. Under this technical framework, the innovative content of the present application and its improvement to the prior art can be specifically presented by digital software products. The software product contains a series of executable codes, which can completely or partially implement the technical processes described in each embodiment of the patent when loaded and run on a computing device (including but not limited to a personal terminal, a cloud server or a network node, etc.).

[0056] Embodiment 3 Based on the method in the above embodiments, the embodiment of the present application provides a computer readable storage medium, which stores a computer program. When the computer program runs on a processor, the processor executes the method in the above embodiments.

[0057] Embodiment 4 Based on the method in the above embodiments, the embodiment of the present application provides a computer program product, which runs on a processor to make the processor execute the method in the above embodiments.

[0058] It can be understood that the processor in the embodiment of the present application can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. The general-purpose processor can be a microprocessor or any conventional processor.

[0059] The method steps in the embodiments of the present application can be implemented by hardware, or by a manner that a processor executes software instructions. The software instructions can be composed of corresponding software modules, and the software modules can be stored in a random access memory (RAM), a flash memory, a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically EPROM (EEPROM), a register, a hard disk, a mobile hard disk, a CD-ROM, or any other form of storage medium well known in the art. An exemplary storage medium is coupled to the processor, so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an ASIC.

[0060] In the above embodiments, all or part of the embodiments can be implemented by software, hardware, firmware, or any combination thereof. When implemented by software, all or part of the embodiments can be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted by the computer-readable storage medium. The computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center through a wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) manner. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that includes one or more available media sets. The available media can be a magnetic medium (such as a floppy disk, a hard disk, a magnetic tape), an optical medium (such as a DVD), or a semiconductor medium (such as a solid state disk (SSD)), etc.

[0061] It can be understood that the various numerical numbers involved in the embodiments of the present application are only for the convenience of differentiation, and do not limit the scope of the embodiments of the present application.

[0062] Those skilled in the art can easily understand that the above description is only the preferred embodiment of the present application, and is not used to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

[0063] Although the specific embodiments of the present application have been described above, it should be understood by those skilled in the art that the specific embodiments described are only illustrative, and are not used to limit the scope of the present application, and the modifications and changes made by those skilled in the art in accordance with the spirit of the present application should be included in the protection scope of the claims of the present application.

Claims

1. A synchronous trajectory planning and execution control method for depth tracking of underactuated underwater vehicles, characterized in that, include: Acquire the desired depth control target and feedback status of the underwater vehicle; The status feedback includes: depth feedback, velocity feedback, pitch angle feedback, and pitch angle velocity feedback; Based on the depth error, an adaptive line-of-sight guidance algorithm is designed to obtain the desired pitch angle of the underwater vehicle. By combining the feedback pitch angle and the desired pitch angle, the tracking error and tracking error velocity of the pitch angle are determined; by combining the tracking error and error velocity constraint information, polynomial trajectory planning is performed to obtain the desired pitch angle acceleration. Based on the desired pitch angle acceleration and state feedback information, an adaptive compensation estimation method for nonlinear disturbances is designed to compensate for the coupled disturbances of external environmental forces and dynamics. A synchronous planning and execution controller with nonlinear disturbance adaptive compensation is used, combined with the above-mentioned desired pitch angle acceleration and nonlinear disturbance compensation estimation, to obtain the rudder angle of the underwater vehicle.

2. The synchronous trajectory planning and execution control method for depth tracking of underactuated underwater vehicles according to claim 1, characterized in that, The adaptive line-of-sight guidance law is expressed as follows: ； in, This represents the desired pitch angle provided by the guidance law. Represents the arctangent function. Indicates depth tracking error. and This represents the parameters of the adaptive line-of-sight guidance law. This indicates the angle-of-attack compensation term for the underwater vehicle. express The first-order differential, This represents the resultant velocity of an underwater vehicle at the depth level.

3. The synchronous trajectory planning and execution control method for depth tracking of underactuated underwater vehicles according to claim 1, characterized in that, The polynomial trajectory planning is expressed as: ； in, , , and The coefficients are undetermined in the polynomial programming problem. For polynomial programming time.

4. The synchronous trajectory planning and execution control method for depth tracking of underactuated underwater vehicles according to claim 3, characterized in that, The solution for the undetermined coefficients must satisfy the following tracking error constraints: ； ； in, Defined as pitch tracking error, and They represent the current time. Tracking error and speed; and Representing future moments The expected convergence error and speed.

5. The synchronous trajectory planning and execution control method for depth tracking of underactuated underwater vehicles according to claims 1 and 3, characterized in that, The desired pitch acceleration under the polynomial trajectory planning is expressed as: ； in, Calculated for the current time second derivative of polynomial .

6. The synchronous trajectory planning and execution control method for depth tracking of underactuated underwater vehicles according to claims 1 and 5, characterized in that, The nonlinear disturbance adaptive compensation estimate is: ； in, and These represent the current sampling period. i and the previous sampling period i Nonlinear disturbances within -1; The parameters represent the nonlinear perturbation estimation.

7. The synchronous trajectory planning and execution control method for depth tracking of underactuated underwater vehicles according to claims 1 and 6, characterized in that, The desired control rudder angle control law of the synchronous planning and execution control method is: ； in, This is the proportional parameter between the rudder angle and the acceleration.

8. A synchronous trajectory planning and execution control system for depth tracking of underactuated underwater vehicles, characterized in that, include: The parameter acquisition unit is used to acquire feedback status such as the desired depth control target, real-time depth, real-time speed, real-time pitch angle, and real-time pitch angular velocity of the underwater vehicle. The outer ring control unit is used to determine the depth error between the desired depth and the real-time depth, and to obtain the desired pitch angle of the underwater vehicle based on the adaptive line-of-sight guidance law. The inner loop control unit is used to calculate the control rudder angle of the underwater vehicle by combining the estimated nonlinear disturbance term of the underwater vehicle and the desired pitch angle acceleration term. The vehicle control unit is used to control the elevator of the underwater vehicle based on the rudder angle so that the underwater vehicle travels at the desired depth.

9. An electronic device, characterized in that, include: At least one memory for storing computer programs; At least one processor is configured to execute a program stored in the memory, wherein when the program stored in the memory is executed, the processor is configured to perform the method as described in any one of claims 1-6.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is run on the processor, it causes the processor to perform the method as described in any one of claims 1-7.

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