Spacecraft attitude fault-tolerant tracking control method based on predefined time disturbance observer

Abstract

The present application relates to a kind of spacecraft attitude fault-tolerant tracking control method based on predefined time disturbance observer, belong to spacecraft attitude control technical field, method includes: establishing spacecraft attitude model and introducing actuator failure;Predefined time nonlinear disturbance observer is constructed, the collective disturbance including external disturbance, inertia uncertainty and actuator failure is accurately estimated within preset time;Predefined time attitude tracking controller is designed based on backstepping method, and the output of observer is used for feedforward compensation, so that attitude and angular velocity tracking error converges to the original point small neighborhood within preset time.The present application can be preset on the upper bound of convergence time and independent of initial state, effectively suppress the influence of disturbance and failure, with high precision and strong robustness.

Description

Technical Field

[0001] This invention belongs to the field of spacecraft attitude control technology, specifically relating to a spacecraft attitude fault-tolerant tracking control method based on a predefined time disturbance observer. Background Technology

[0002] Spacecraft attitude control technology has significant application value in many fields such as information communication, resource exploration, meteorological monitoring, and safety rescue, and is also one of the core technologies for completing various space missions. However, in actual space systems, they are often inevitably affected by a variety of uncertain factors, such as external interference, uncertainties in rotational inertia parameters, and non-ideal factors such as actuator efficiency loss and failure. These factors can reduce the accuracy and reliability of attitude control.

[0003] In existing technologies, while finite-time control methods can achieve fast convergence, their convergence time depends on the initial state of the system. Fixed-time control methods, although their upper bound on convergence time is independent of the initial state, still depend on system parameters and cannot be directly specified by the designer. Predefined time control methods can overcome these limitations, as their upper bound on convergence time can be preset by the designer and is independent of the initial state of the system. However, most existing predefined time control methods focus on attitude stabilization problems, with limited research on attitude tracking problems, and few simultaneously consider the fusion design of actuator failures and disturbance observers.

[0004] Therefore, how to simultaneously achieve predefined time convergence, effective suppression of external disturbances and parameter uncertainties, and fault tolerance for actuator failures in spacecraft attitude tracking control has become a pressing technical problem to be solved in this field. Summary of the Invention

[0005] In view of this, the present invention provides a spacecraft attitude fault-tolerant tracking control method based on a predefined time disturbance observer, in order to improve the accuracy, robustness and engineering applicability of spacecraft attitude tracking control.

[0006] In a first aspect, the present invention provides a spacecraft attitude fault-tolerant tracking control method based on a predefined time disturbance observer, the method comprising:

[0007] S1. Establish a spacecraft attitude kinematics and dynamics model, and introduce actuator efficiency loss faults into the model; S2. Based on the spacecraft attitude kinematics and dynamics model, define attitude tracking error and angular velocity tracking error, derive the corresponding attitude error dynamic equations, and construct the spacecraft attitude tracking motion model. S3. Construct a predefined time nonlinear disturbance observer. The time nonlinear disturbance observer is used to estimate the lumped disturbance that includes external disturbances, inertia uncertainty and actuator failure, so that the observation error converges to zero within a preset time and outputs the real-time estimate of the lumped disturbance. S4. A predefined time attitude tracking controller is designed using the backstepping method. Feedforward compensation is performed through the observer output so that the attitude tracking error and angular velocity tracking error converge to a small neighborhood near the origin within a preset time.

[0008] Optionally, in step S1, the spacecraft attitude kinematics and dynamics model is as follows: ; ; in, The Rodriguez parameter is used to correct the spacecraft's attitude. This is the spacecraft's angular velocity vector; The inertia matrix of the spacecraft; To control the torque vector; This represents the external disturbance torque vector. ; for The cross product matrix.

[0009] Optionally, in step S1, the actuator efficiency loss fault is: ; in, This is the actual acting torque; The desired torque; Let be the time-varying actuator efficiency matrix, satisfying ,when The actuator works normally when The actuator experienced a partial efficiency loss failure.

[0010] Optionally, step S2 specifically includes the following steps: S21. Define attitude tracking error and angular velocity tracking error for: ; ; S22. Derive the attitude tracking error and angular velocity tracking error The dynamic equation of attitude error: ; ; in, As desired, The desired angular velocity; Let be the rotation matrix from the desired system to the system itself. This indicates a correction to the Rodriguez parameter multiplication.

[0011] Optionally, in step S3, the lumped interference is: ; The formula for the dynamics of angular velocity error is obtained by reconstructing the spacecraft dynamics model: ; in, The nominal inertia matrix of the spacecraft. For the uncertain part of inertia, satisfying Define the known part for: .

[0012] Optionally, in step S3, the step of constructing a predefined time nonlinear disturbance observer includes: S31. Define auxiliary variables and observation error ,in This refers to the angular velocity tracking error. S32. The observer's dynamic equation is: ; ; ; in, for The estimated value, For observation estimation error; The gain is constant. The observer gain is ; This is the preset observer convergence time; , , .

[0013] Optionally, in step S4, the specific steps of designing a predefined time-attitude tracking controller using the backstepping method include: S41. Design a virtual controller: ; in, , ; This is the preset controller convergence time; , , ; S42. Define intermediate error Design the actual control law: ; in, , , ; This is the preset controller convergence time; , , .

[0014] Optionally, in step S4, the attitude tracking error and angular velocity tracking error are within a preset time. It converges inward to a small neighborhood near the origin, where... Set a convergence time for the observer. Set a convergence time for the controller.

[0015] In a second aspect, embodiments of the present invention provide a computer-readable storage medium comprising a stored program, wherein, when the program is executed, the device on which the computer-readable storage medium is located executes the spacecraft attitude fault-tolerant tracking control method based on a predefined time disturbance observer, as described in the first aspect or any possible implementation thereof.

[0016] Thirdly, embodiments of the present invention provide an electronic device, including: one or more processors; a memory; and one or more computer programs, wherein the one or more computer programs are stored in the memory, and the one or more computer programs include instructions that, when executed by the device, cause the device to perform the spacecraft attitude fault-tolerant tracking control method based on a predefined time disturbance observer in the first aspect or any possible implementation of the first aspect.

[0017] As can be seen from the above technical solutions, the present invention has the following advantages: The observer and controller of this invention both adopt a predefined time design. The upper bound of the convergence time can be directly specified by the designer according to the timing of the space mission. It is completely independent of the initial state and system parameters of the system, and can accurately match the attitude tracking time node requirements of various space missions, thereby improving the predictability and reliability of mission execution.

[0018] This invention models external space disturbances, spacecraft rotational inertia parameter uncertainties, and actuator efficiency loss faults into a unified lumped disturbance. By using a predefined time nonlinear disturbance observer, it achieves unbiased and accurate estimation of the lumped disturbance within a preset time. The estimated value is then introduced into the controller for feedforward compensation, realizing synchronous suppression and active fault tolerance of non-ideal factors. This solves the problems of decreased attitude control accuracy and system instability under complex space environments and actuator failure conditions, and improves the robustness and survivability of the spacecraft attitude tracking system.

[0019] Breaking through the limitations of existing predefined timing control methods that mostly focus on attitude stability and lack sufficient research on attitude tracking scenarios, a control architecture was specifically designed for spacecraft attitude tracking missions. This architecture achieves the matching of predefined timing characteristics between disturbance observation and attitude control, avoiding performance loss caused by mismatch between observation and control timing.

[0020] The controller is designed using the backstepping method, which has a clear structure, rigorous logic, no singularity issues, and low computational complexity. It can achieve real-time operation with limited computer computing resources and can be directly applied to attitude tracking and control tasks of various satellites, probes, and space station modules in fields such as information communication, resource exploration, meteorological monitoring, and safety rescue. Attached Figure Description

[0021] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A flowchart illustrating the spacecraft attitude fault-tolerant tracking control method based on a predefined time disturbance observer provided in an embodiment of the present invention; Figure 2 This is a simulation diagram illustrating the changes in attitude tracking error and angular velocity tracking error provided in an embodiment of the present invention. Figure 2 In the figure, (a) represents the attitude tracking error. Figure 2 (b) in the figure represents the angular velocity tracking error; Figure 3 This is a simulation diagram illustrating the control torque variation and intermediate error response provided in an embodiment of the present invention, wherein... Figure 3 (a) in the figure represents the control torque. Figure 3 (b) in the figure represents the intermediate error response; Figure 4 This is a simulation diagram illustrating the perturbation estimation performance provided in an embodiment of the present invention, wherein, Figure 4 (a) in the text represents external interference. Figure 4(b) represents the uncertainty of inertia. Figure 4 (c) in the diagram represents an actuator failure; Figure 5 This is a simulation diagram illustrating the change in the health coefficient of the actuator provided in an embodiment of the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” used in the embodiments of this invention are also intended to include the plural forms unless the context clearly indicates otherwise. It should be understood that the term “and / or” as used herein is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. Additionally, the character “ / ” in this document generally indicates that the preceding and following related objects are in an “or” relationship. Depending on the context, the word “if” as used herein can be interpreted as “when…”, “when…”, “in response to determination,” or “in response to detection.” Similarly, depending on the context, the phrases “if determination” or “if detection (of the stated condition or event)” can be interpreted as “when determination”, “in response to determination,” “when detection (of the stated condition or event),” or “in response to detection (of the stated condition or event).”

[0025] This invention provides a spacecraft attitude fault-tolerant tracking control method based on a predefined time disturbance observer. The method will be described in detail below with reference to the accompanying drawings. Figure 1 This is a flowchart illustrating a spacecraft attitude fault-tolerant tracking control method based on a predefined time disturbance observer, provided in an embodiment of the present invention. The method includes the following steps: S1. Establish a spacecraft attitude kinematics and dynamics model, and introduce actuator efficiency loss faults into the model; S2. Based on the spacecraft attitude kinematics and dynamics model, define attitude tracking error and angular velocity tracking error, derive the corresponding attitude error dynamic equations, and construct the spacecraft attitude tracking motion model. S3. Construct a predefined time nonlinear disturbance observer. The time nonlinear disturbance observer is used to estimate the lumped disturbance that includes external disturbances, inertia uncertainty and actuator failure, so that the observation error converges to zero within a preset time and outputs the real-time estimate of the lumped disturbance. S4. A predefined time attitude tracking controller is designed using the backstepping method. Feedforward compensation is performed through the observer output so that the attitude tracking error and angular velocity tracking error converge to a small neighborhood near the origin within a preset time.

[0026] It should be noted that this embodiment achieves accurate estimation of lumped disturbances, including external disturbances, inertia uncertainty and actuator failure, within a preset time by constructing a predefined time nonlinear disturbance observer; the predefined time attitude tracking controller based on the backstepping method uses the observer output for feedforward compensation, so that the attitude and angular velocity tracking errors converge to a small neighborhood near the origin within a preset time.

[0027] As a refinement and extension of the specific implementation of the above embodiments, in order to fully illustrate the specific implementation process in this embodiment, another spacecraft attitude fault-tolerant tracking control method based on a predefined time disturbance observer is provided. This method includes the following steps: S1. Establish a spacecraft attitude kinematics and dynamics model, and introduce actuator efficiency loss faults into the model; In step S1, the spacecraft attitude kinematics and dynamics model is as follows: ; ; in, The Rodriguez parameter is used to correct the spacecraft's attitude. This is the spacecraft's angular velocity vector; The inertia matrix of the spacecraft; To control the torque vector; This represents the external disturbance torque vector. ; for The cross product matrix.

[0028] In step S1, the actuator efficiency loss fault is: ; in, This is the actual acting torque; The desired torque; Let be the time-varying actuator efficiency matrix, satisfying ,when The actuator works normally when The actuator experienced a partial efficiency loss failure.

[0029] S2. Based on the spacecraft attitude kinematics and dynamics model, define attitude tracking error and angular velocity tracking error, derive the corresponding attitude error dynamic equations, and construct the spacecraft attitude tracking motion model. Step S2 includes the following specific steps: S21. Define attitude tracking error and angular velocity tracking error for: ; ; S22. Derive the attitude tracking error and angular velocity tracking error The dynamic equation of attitude error: ; ; in, As desired, The desired angular velocity; Let be the rotation matrix from the desired system to the native system. This indicates a correction to the Rodriguez parameter multiplication.

[0030] S3. Construct a predefined time nonlinear disturbance observer. The time nonlinear disturbance observer is used to estimate the lumped disturbance that includes external disturbances, inertia uncertainty and actuator failure, so that the observation error converges to zero within a preset time and outputs the real-time estimate of the lumped disturbance. In step S3, the lumped interference is: ; To facilitate observer design, the spacecraft dynamics model is reconstructed, and the formula for angular velocity error dynamics is as follows: ; in, The nominal inertia matrix of the spacecraft. For the uncertain part of inertia, satisfying Define the known part for: .

[0031] In step S3, the step of constructing a predefined time nonlinear disturbance observer includes: S31. Define auxiliary variables and observation error ,in This refers to the angular velocity tracking error. S32. The observer's dynamic equation is: ; ; ; in, for The estimated value, For observation estimation error; The gain is constant. The observer gain is ; This is the preset observer convergence time; , , .

[0032] S4. A predefined time attitude tracking controller is designed using the backstepping method. Feedforward compensation is performed through the observer output so that the attitude tracking error and angular velocity tracking error converge to a small neighborhood near the origin within a preset time.

[0033] In step S4, the specific steps for designing a predefined time-attitude tracking controller using the backstepping method include: S41. Design a virtual controller: ; in, , ; This is the preset controller convergence time; , , ; S42. Define intermediate error Design the actual control law: ; in, , , ; This is the preset controller convergence time; , , .

[0034] In step S4, the attitude tracking error and angular velocity tracking error are within a preset time. It converges inward to a small neighborhood near the origin, where... Set a convergence time for the observer. A preset convergence time is set for the controller. By constructing a Lyapunov function and performing stability analysis, it can be proven that under the above control law, the attitude and angular velocity tracking errors will converge within the preset time. It converges to a small neighborhood near the origin. The upper bound of the convergence time is preset by the designer and is independent of the initial state of the system, demonstrating the superiority of predefined time control.

[0035] In this embodiment of the invention, Figure 2 The graph shows the variation curves of attitude tracking error and angular velocity tracking error. As can be seen from the graph, the attitude and angular velocity tracking errors converge rapidly to a small neighborhood within a preset time. This indicates that the spacecraft successfully tracked the desired attitude, and the convergence process was smooth and without overshoot, verifying the effectiveness of the predefined time controller.

[0036] In embodiments of the present invention, such as Figure 3 As shown, the control torque is smooth and free of chattering, verifying the effectiveness and robustness of the method of this invention. The intermediate error converges rapidly under the action of the controller, demonstrating the advantages of the backstepping method design.

[0037] In this embodiment of the invention, Figure 4 For perturbation estimation performance curves, Figure 5 The figure shows the change curve of the actuator health coefficient. As can be seen from the figure, the designed predefined time disturbance observer can accurately estimate the lumped disturbance (including external disturbance, inertia uncertainty and actuator failure), the observation error converges to zero within the preset time, and it has good adaptability to actuator failure.

[0038] As can be seen from the simulation results, the effectiveness and robustness of the spacecraft attitude fault-tolerant tracking control method based on a predefined time disturbance observer proposed in this invention are fully verified. It can achieve attitude tracking within a preset time and has a strong ability to suppress external disturbances, inertia uncertainty and actuator failure.

[0039] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0040] This invention also provides a computer-readable storage medium, which includes a stored program, wherein the program, when running, controls the device where the computer-readable storage medium is located to execute the aforementioned spacecraft attitude fault-tolerant tracking control method based on a predefined time disturbance observer.

[0041] This invention also provides an electronic device, including: one or more processors; a memory; and one or more computer programs, wherein the one or more computer programs are stored in the memory, and the one or more computer programs include instructions that, when executed by the device, cause the device to perform the above-described spacecraft attitude fault-tolerant tracking control method based on a predefined time disturbance observer.

[0042] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A spacecraft attitude fault-tolerant tracking control method based on a predefined time disturbance observer, characterized in that, The method includes the following steps: S1. Establish a spacecraft attitude kinematics and dynamics model, and introduce actuator efficiency loss faults into the model; S2. Based on the spacecraft attitude kinematics and dynamics model, define attitude tracking error and angular velocity tracking error, derive the corresponding attitude error dynamic equations, and construct the spacecraft attitude tracking motion model. S3. Construct a predefined time nonlinear disturbance observer. The time nonlinear disturbance observer is used to estimate the lumped disturbance that includes external disturbances, inertia uncertainty and actuator failure, so that the observation error converges to zero within a preset time and outputs the real-time estimate of the lumped disturbance. S4. A predefined time attitude tracking controller is designed using the backstepping method. Feedforward compensation is performed through the observer output so that the attitude tracking error and angular velocity tracking error converge to a small neighborhood near the origin within a preset time.

2. The spacecraft attitude fault-tolerant tracking control method based on a predefined time disturbance observer according to claim 1, characterized in that, In step S1, the spacecraft attitude kinematics and dynamics model is as follows: ； ； in, The Rodriguez parameter is used to correct the spacecraft's attitude. This is the spacecraft's angular velocity vector; The inertia matrix of the spacecraft; To control the torque vector; This represents the external disturbance torque vector; ; for The cross product matrix.

3. The spacecraft attitude fault-tolerant tracking control method based on a predefined time disturbance observer according to claim 1, characterized in that, In step S1, the actuator efficiency loss fault is: ； in, This is the actual acting torque; The desired torque; The time-varying actuator efficiency matrix satisfies ,when The actuator works normally when The actuator experienced a partial efficiency loss failure.

4. The spacecraft attitude fault-tolerant tracking control method based on a predefined time disturbance observer according to claim 1, characterized in that, Step S2 includes the following specific steps: S21. Define attitude tracking error and angular velocity tracking error for: ； ； S22. Derive the attitude tracking error and angular velocity tracking error The dynamic equation of attitude error: ； ； in, As desired, The desired angular velocity; Let be the rotation matrix from the desired system to the native system. This indicates a correction to the Rodriguez parameter multiplication.

5. The spacecraft attitude fault-tolerant tracking control method based on a predefined time disturbance observer according to claim 1, characterized in that, In step S3, the lumped interference is: ； The formula for the dynamics of angular velocity error is obtained by reconstructing the spacecraft dynamics model: ； in, The nominal inertia matrix of the spacecraft. For the uncertain part of inertia, satisfying Define the known part for: 。 6. The spacecraft attitude fault-tolerant tracking control method based on a predefined time disturbance observer according to claim 1, characterized in that, In step S3, the step of constructing a predefined time nonlinear disturbance observer includes: S31. Define auxiliary variables and observation error ,in This refers to the angular velocity tracking error. S32. The observer's dynamic equation is: ； ； ； in, for The estimated value, For observation estimation error; The gain is constant. The observer gain is ; This is the preset observer convergence time; , , .

7. The spacecraft attitude fault-tolerant tracking control method based on a predefined time disturbance observer according to claim 1, characterized in that, In step S4, the specific steps for designing a predefined time-attitude tracking controller using the backstepping method include: S41. Design a virtual controller: ； in, , ; This is the preset controller convergence time; , , ; S42. Define intermediate error Design the actual control law: ； in, , , ; This is the preset controller convergence time; , , .

8. The spacecraft attitude fault-tolerant tracking control method based on a predefined time disturbance observer according to claim 1, characterized in that, In step S4, the attitude tracking error and angular velocity tracking error are within a preset time. It converges inward to a small neighborhood near the origin, where... Set a convergence time for the observer. Set a convergence time for the controller.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform the spacecraft attitude fault-tolerant tracking control method based on a predefined time disturbance observer as described in any one of claims 1 to 8.

10. An electronic device, characterized in that, include: One or more processors; Memory; And one or more computer programs, wherein the one or more computer programs are stored in the memory, the one or more computer programs including instructions that, when executed by the device, cause the device to perform the spacecraft attitude fault-tolerant tracking control method based on a predefined time disturbance observer as described in any one of claims 1 to 8.

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