Spacecraft preset time and preset precision attitude tracking control method and system based on performance function

Abstract

The invention discloses a spacecraft preset-time preset-precision attitude tracking control method and system based on a performance function, and relates to the field of spaceflight. The problem that according to an existing preset-time and preset-precision attitude control method, the upper bound of disturbance torque is required to be known, or singularity exists, or the attitude error at the initial moment is required to be within a certain range is solved. The method comprises the following steps: establishing an attitude dynamic model of a spacecraft according to modified Rodrigues parameters; designing a performance function, and performing mathematical transformation on the attitude tracking error of the attitude dynamics model of the spacecraft; constructing a continuous nonsingular adaptive attitude tracking controller; and according to the continuous nonsingular self-adaptive attitude tracking controller, realizing attitude tracking control of the spacecraft in preset time and preset precision. The method is applied to the field of spacecraft attitude control.

Description

Technical Field

[0001] The present invention relates to the field of aerospace, and in particular to a spacecraft preset time preset accuracy attitude tracking control method based on a performance function. Background Art

[0002] Spacecraft attitude control is an important research direction in the field of aerospace, which is related to the successful implementation of various space missions. According to the speed at which the attitude error tends to zero, the existing attitude control methods can be divided into asymptotic control, finite time control, fixed time control and preset time control. Compared with asymptotic control, finite time control and fixed time control can ensure that the attitude error converges to zero or close to zero in a finite time, but the upper bound of their convergence time usually has a complex functional relationship with the controller parameters or the initial conditions of the system. In contrast, preset time control can make the attitude error converge to the required accuracy within a clear time upper bound under any initial conditions, and this time upper bound can be easily adjusted according to mission requirements.

[0003] The traditional preset time control method can only ensure that the attitude error converges to near zero within the preset time, but the specific convergence accuracy cannot be determined. For this reason, preset time and preset accuracy control came into being. It can converge the attitude error to a neighborhood of known size near zero within the preset time, effectively solving the problem of difficult to determine the convergence accuracy. Wang Yunteng, Xiao Yan, Ye Dong and others disclosed the terminal sliding mode control method in the "Preset Time and Preset Accuracy Attitude Tracking Control of Rigid Spacecraft" published in 2023. It is a method that can be used to design preset time and preset accuracy control, but it requires that the upper bound of the disturbance to the system must be known, which constitutes its limitation. On the other hand, the performance function provides another effective tool for achieving preset time and preset accuracy control because it does not require the upper bound of the disturbance to be known. However, the existing preset time and preset accuracy control methods based on performance functions have some problems in practical applications, such as the possible existence of singularities, such as: "Adaptive Sliding Mode Attitude-Tracking Control of Spacecraft with Prescribed Time Performance" published by Runze Chen, Zhenling Wang, Weiwei Che et al. in 2022, or only effective when the initial attitude error does not exceed a certain range, such as: "Novel Finite-Time Adaptive Neural Control of Flexible Spacecraft with Actuator Constraints and Prescribed Attitude Tracking Performance" published by Jiawei Tao, Tao Zhang, Qirui Liu et al. in 2021. Therefore, although the preset time and preset accuracy control shows good prospects, further research and optimization are still needed to overcome these limitations. Summary of the invention

[0004] The present invention aims at the shortcomings of the existing preset time and preset accuracy attitude control methods, which either require the upper bound of the disturbance torque to be known, or have singularity problems, or require that the initial attitude error must be within a certain range. A spacecraft preset time and preset accuracy attitude tracking control method based on a performance function is proposed. The method comprises:

[0005] S1: Establish the attitude dynamics model of the spacecraft based on the modified Rodriguez parameters MRPs;

[0006] S2: Design performance functions and mathematically transform attitude tracking errors in the attitude dynamics model of the spacecraft;

[0007] S3: Construct a continuous non-singular adaptive attitude tracking controller;

[0008] S4: Implementing attitude tracking control of the spacecraft with a preset time and preset accuracy based on a continuous non-singular adaptive attitude tracking controller.

[0009] Furthermore, a preferred method is proposed, wherein step S1 comprises:

[0010]

[0011] Among them, σ∈R 3 is the spacecraft attitude expressed in MRPs, ω∈R 3 is the angular velocity of the spacecraft, J∈R 3×3 is the moment of inertia matrix of the spacecraft relative to its center of mass, τ∈R 3 is the control input applied by the actuator, d∈R 3 is the disturbance torque.

[0012] Furthermore, a preferred method is proposed, wherein step S2 comprises:

[0013] The error posture dynamics model is:

[0014]

[0015] in, is the time rate of change of attitude tracking error, T(σ e ) is the error attitude kinematic matrix, ω e is the angular velocity tracking error, σ e is the posture tracking error, is the time rate of change of angular velocity tracking error, and f is the intermediate variable;

[0016] Design performance function:

[0017]

[0018] Among them, β(t) is the performance function, T p is the preset time constant, t is the time variable, and ε is a positive constant.

[0019] Furthermore, a preferred method is proposed, wherein the posture tracking error is specifically:

[0020]

[0021] Among them, σ d For the target posture, is the target posture σ d (t) The corresponding cross product matrix.

[0022] Furthermore, a preferred embodiment is proposed, wherein the angular velocity tracking error is specifically:

[0023] ω e =ω-C qe ω d

[0024] Among them, C qe is the rotation matrix from the target body coordinate system to the actual body coordinate system, ω d is the target angular velocity.

[0025] Furthermore, a preferred method is proposed, wherein step S3 comprises:

[0026]

[0027] Where τ is the control torque, S T (σ e ) is the intermediate variable matrix S(σ e ), Θ is the intermediate variable, is the intermediate variable, is the adaptive parameter, is the adaptive parameter, K 0 is a symmetric positive definite matrix.

[0028] Furthermore, a preferred method is proposed, wherein step S4 comprises:

[0029]

[0030] Among them, h is the intermediate variable, s is the intermediate variable, K 1 is a symmetric positive definite matrix, c, g 1 and g 2 is a normal number.

[0031] Based on the same inventive concept, the present invention also proposes a spacecraft preset time preset accuracy attitude tracking control system based on a performance function, the system comprising: an onboard computer, an actuator, a spacecraft body, an onboard attitude sensor and an onboard angular velocity sensor; the onboard computer stores the above-mentioned tracking control method;

[0032] The onboard computer generates control signals based on the expected and current attitude of the spacecraft;

[0033] The control signal is used to drive the actuator to generate control torque;

[0034] The actuator applies torque to the spacecraft body, thereby changing the spacecraft attitude and angular velocity;

[0035] The onboard attitude sensor and onboard angular velocity sensor capture the spacecraft attitude and angular velocity information and feed the data back to the onboard computer;

[0036] After receiving the feedback signal, the onboard computer compares it with the desired attitude and adjusts the control signal again based on the deviation to ensure that the spacecraft can reach or maintain the desired attitude.

[0037] Based on the same inventive concept, the present invention also proposes a computer device, including a memory and a processor, wherein the memory stores a computer program. When the processor runs the computer program stored in the memory, the processor executes a spacecraft preset time preset accuracy attitude tracking control method based on a performance function according to any one of the above.

[0038] Based on the same inventive concept, the present invention also proposes a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of a spacecraft preset time preset accuracy attitude tracking control method based on a performance function as described in any of the above items are executed.

[0039] The present invention is beneficial in that:

[0040] Existing methods usually require the upper bound of the disturbance torque to be known, but in practical applications, this limit is often difficult to obtain accurately, resulting in unsatisfactory control effects. The method proposed in the present invention no longer requires the upper bound of the disturbance torque to be known through the design of performance functions and adaptive rules.

[0041] Sometimes singularity occurs in the attitude control of spacecraft, especially in certain specific attitudes, the controller may fail or become unstable. The method proposed in the present invention designs a continuous non-singular attitude tracking controller, which can effectively avoid the influence of singularity on the control effect.

[0042] Traditional control methods based on performance functions usually require that the initial attitude error is within a certain range, which limits the flexibility of practical applications. The method proposed in the present invention reduces the requirements for initial conditions through improved mathematical models and control strategies, so that effective control can be achieved under a wider range of conditions.

[0043] In the performance function-based spacecraft preset time preset accuracy attitude tracking control method proposed by the present invention, the modified Rodriguez parameters are used to establish the attitude dynamics model of the spacecraft, which can effectively describe the three-dimensional rotation of the spacecraft and avoid the singularity problem of the traditional Euler angle method. By constructing the performance function and combining the attitude tracking error for mathematical conversion, the control target is clearer and the control strategy can be flexibly adjusted to meet different needs. The design of the controller is based on ensuring that non-singularity is maintained at all times to ensure that the controller is stable and reliable when processing attitude tracking.

[0044] Through the design of adaptive rules, the controller can dynamically adjust parameters according to the actual operating status, improving the flexibility and accuracy of control.

[0045] The present invention proposes a spacecraft preset time preset accuracy attitude tracking control method based on performance function, which can maintain high control performance without relying on known disturbance torque and enhance the robustness to external interference. The restriction on initial attitude error is reduced, making the method applicable to more practical situations and improving the operational flexibility of the spacecraft. The continuous non-singular attitude tracking controller design ensures stable control in various attitudes and avoids control failure due to singularity. The addition of adaptive rules allows the control system to be adjusted in real time, which can better cope with dynamic environmental changes and improve the accuracy and response speed of attitude tracking.

[0046] The present invention proposes a spacecraft preset time preset accuracy attitude tracking control system based on performance function, which can quickly evaluate the current state, compare it with the expected attitude, and generate an adjusted control signal by receiving attitude and angular velocity information in real time through the onboard computer. This fast feedback mechanism ensures that the spacecraft can respond to attitude changes in a timely manner, and enhances the stability and reliability of the system. Using the high-precision data provided by the onboard attitude sensor and angular velocity sensor, the system can accurately calculate the attitude error, thereby more effectively adjusting the control signal to ensure that the spacecraft reaches or maintains the target attitude within the preset time. The system can adjust the control strategy in real time according to environmental changes and external disturbances, adapt to different flight states and mission requirements, and improve the operational flexibility of the spacecraft under complex tasks. The system tightly integrates computers, sensors and actuators to form a comprehensive attitude control solution, which improves the overall performance and maintenance efficiency of the system. The introduction of the control method based on performance function enables the system to balance the response speed and steady-state error during design, ensuring that the spacecraft has the best tracking performance when performing tasks. Since the system can automatically process and adjust the control signal, it reduces the dependence on manual intervention and improves the automation and operational safety of the task.

[0047] The present invention is applied to the field of spacecraft attitude control. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a flow chart of a spacecraft preset time preset accuracy attitude tracking control method based on a performance function as described in implementation mode 1;

[0049] Figure 2 A schematic diagram of a spacecraft preset time preset accuracy attitude tracking control system based on a performance function as described in Implementation Example 8;

[0050] Figure 3 This is a schematic diagram of the posture tracking error described in the eleventh embodiment;

[0051] Figure 4 This is a schematic diagram of the angular velocity tracking error according to the eleventh embodiment;

[0052] Figure 5 This is a schematic diagram of the control torque described in the eleventh embodiment. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0054] Implementation method 1, see Figure 1 The present embodiment describes a spacecraft preset time preset accuracy attitude tracking control method based on a performance function, the method comprising:

[0055] S1: Establish the attitude dynamics model of the spacecraft based on the modified Rodriguez parameters MRPs;

[0056] S2: Design performance functions and mathematically transform attitude tracking errors of the attitude dynamics model of the spacecraft;

[0057] S3: Construct a continuous non-singular adaptive attitude tracking controller;

[0058] S4: Implementing attitude tracking control of the spacecraft with a preset time and preset accuracy based on a continuous non-singular adaptive attitude tracking controller.

[0059] Existing methods usually require that the upper bound of the disturbance torque is known, but in practical applications, this limitation is often difficult to obtain accurately, resulting in unsatisfactory control effects. In this embodiment, through the design of the performance function, it is no longer mandatory to require that the upper bound of the disturbance torque is known.

[0060] Singularities sometimes occur in the attitude control of spacecraft, especially in certain specific attitudes, the controller may fail or become unstable. This method designs a continuous non-singular attitude tracking controller, which can effectively avoid the influence of singularities on the control effect.

[0061] Traditional performance function-based control methods usually require that the initial attitude error is within a certain range, which limits the flexibility of practical applications. In this embodiment, the requirements for initial conditions are reduced through improved mathematical models and control strategies, so that effective control can be achieved under a wider range of conditions.

[0062] The method proposed in this embodiment uses the modified Rodriguez parameters to establish the attitude dynamics model of the spacecraft, which can effectively describe the three-dimensional rotation of the spacecraft and avoid the singularity problem of the traditional Euler angle method. The mathematical conversion combined with the attitude tracking error makes the control target clearer, and the control strategy can be flexibly adjusted to meet different needs. The design of the controller is based on ensuring that non-singularity is maintained at all times to ensure that the controller is stable and reliable when processing attitude tracking. Through the design of adaptive rules, the controller can dynamically adjust parameters according to the actual operating status, thereby improving the flexibility and accuracy of control.

[0063] The method proposed in this embodiment can maintain high control performance without relying on known disturbance torque, and enhances the robustness to external disturbances. The limit on the initial attitude error is reduced, making the method applicable to more practical situations and improving the operational flexibility of the spacecraft. The continuous non-singular attitude tracking controller design ensures stable control in various attitudes and avoids control failure due to singularity. The addition of adaptive rules allows the control system to be adjusted in real time, which can better cope with dynamic environmental changes and improve the accuracy and response speed of attitude tracking.

[0064] Embodiment 2: This embodiment further limits the method for posture tracking control with preset time and preset accuracy described in embodiment 1, and step S1 includes:

[0065]

[0066] Among them, σ∈R 3 is the spacecraft attitude expressed in MRPs, ω∈R 3 is the angular velocity of the spacecraft, J∈R 3×3 is the moment of inertia matrix of the spacecraft relative to its center of mass, τ∈R 3 is the control input applied by the actuator, d∈R 3 is the disturbance torque.

[0067] In this implementation, MRPs are used to represent the attitude of the spacecraft, which can effectively avoid singularity problems and ensure continuity and operability in the entire attitude space. By clearly expressing the angular velocity and moment of inertia matrix, the dynamic characteristics of the spacecraft can be described more accurately, and the reliability of the control effect can be improved. The role of the control input is clarified, and the control signal can be applied more effectively in a complex environment to achieve accurate tracking of the attitude. Combined with the introduction of adaptive laws, the control system can better adapt to external disturbances and improve the robustness and stability of the system.

[0068] Implementation method 3: This implementation method further limits the preset time and preset accuracy posture tracking control method described in implementation method 1, and step S2 includes:

[0069] The error posture dynamics model is:

[0070]

[0071] in, is the time rate of change of attitude tracking error, T(σ e ) is the error attitude kinematic matrix, ω e is the angular velocity tracking error, σ e is the posture tracking error, is the time rate of change of angular velocity tracking error, and f is the intermediate variable;

[0072] Design performance function:

[0073]

[0074] Among them, β(t) is the performance function, T p is the preset time constant, t is the time variable, and ε is a positive constant.

[0075] In this embodiment, by defining the time rate of change of the error posture and the kinematic matrix, the dynamic evolution of the posture tracking error can be clearly described, making the control algorithm more targeted. The designed performance function takes into account the preset time constant, which can effectively balance the response speed and steady-state error of the control system to ensure that the required accuracy is achieved within the preset time. With the introduction of the time variable t, the control system can evaluate the current state in real time and dynamically adjust the control strategy to adapt to the actual operating conditions. The constant and variable settings in the design can improve the system's adaptability to external disturbances and uncertainties and enhance the stability of the overall control performance.

[0076] Embodiment 4: This embodiment further limits the attitude tracking control method with a preset time and preset accuracy described in embodiment 3, and the attitude tracking error is specifically:

[0077]

[0078] Among them, σ d For the target posture, is the target posture σ d (t) The corresponding cross product matrix.

[0079] In this embodiment, by introducing the target posture, the error calculation is made more intuitive and accurate, and the gap between the current state and the target state can be clearly reflected. The use of the cross product matrix can effectively convert the posture error into the control input, simplifying the implementation of the control algorithm and improving the calculation efficiency. The clear error definition makes the behavior of the control system easier to understand and analyze, and facilitates subsequent debugging and optimization. By accurately describing the posture tracking error, the control strategy can be better optimized, so that the target posture can be achieved more efficiently within the preset time and the tracking accuracy can be improved.

[0080] Embodiment 5: This embodiment further limits the attitude tracking control method with preset time and preset accuracy described in embodiment 3, and the angular velocity tracking error is specifically:

[0081] ω e =ω-C qe ω d

[0082] Among them, C qe is the rotation matrix from the target body coordinate system to the actual body coordinate system, ω d is the target angular velocity.

[0083] Embodiment 6: This embodiment further limits the method for posture tracking control with preset time and preset accuracy described in embodiment 3, and step S3 includes:

[0084]

[0085] Where τ is the control torque, S T (σ e ) is the intermediate variable matrix S(σ e ), Θ is the intermediate variable, is the intermediate variable, is the adaptive parameter, is the adaptive parameter, K 0 is a symmetric positive definite matrix.

[0086] Embodiment 7: This embodiment further limits the method for posture tracking control with preset time and preset accuracy described in embodiment 1, and step S4 includes:

[0087]

[0088] Among them, h is the intermediate variable, s is the intermediate variable, K 1 is a symmetric positive definite matrix, c, g 1 and g 2 is a normal number.

[0089] Implementation Method 8: See Figure 2 This embodiment is described. This embodiment is a spacecraft preset time preset accuracy attitude tracking control system based on performance function, the system includes: an onboard computer, an actuator, a spacecraft body, an onboard attitude sensor and an onboard angular velocity sensor; the onboard computer stores the tracking control method described in the first embodiment;

[0090] The onboard computer generates control signals based on the expected and current attitude of the spacecraft;

[0091] The control signal is used to drive the actuator to generate control torque;

[0092] The actuator applies torque to the spacecraft body, thereby changing the spacecraft attitude and angular velocity;

[0093] The onboard attitude sensor and onboard angular velocity sensor capture the spacecraft attitude and angular velocity information and feed the data back to the onboard computer;

[0094] After receiving the feedback signal, the onboard computer compares it with the desired attitude and adjusts the control signal again based on the deviation to ensure that the spacecraft can reach or maintain the desired attitude.

[0095] The system described in this embodiment receives attitude and angular velocity information in real time through the onboard computer, can quickly evaluate the current state, compare it with the expected attitude, and generate an adjusted control signal. This fast feedback mechanism ensures that the spacecraft can respond to attitude changes in a timely manner, enhancing the stability and reliability of the system. Using the high-precision data provided by the onboard attitude sensor and angular velocity sensor, the system can accurately calculate the attitude error, thereby more effectively adjusting the control signal to ensure that the spacecraft reaches or maintains the target attitude within the preset time. The system can adjust the control strategy in real time according to environmental changes and external disturbances, adapt to different flight states and mission requirements, and improve the operational flexibility of the spacecraft under complex tasks. The system tightly integrates computers, sensors and actuators to form a comprehensive attitude control solution, which improves the overall performance and maintenance efficiency of the system. The introduction of a control method based on performance functions allows the system to balance response speed and steady-state error during design, ensuring that the spacecraft has the best tracking performance when performing tasks. Since the system can automatically process and adjust control signals, it reduces dependence on manual intervention and improves the automation and operational safety of the task.

[0096] Embodiment 9. A computer device described in this embodiment includes a memory and a processor, wherein the memory stores a computer program. When the processor runs the computer program stored in the memory, the processor executes a spacecraft preset time preset accuracy attitude tracking control method based on a performance function according to any one of embodiments 1 to 7.

[0097] Embodiment 10. A computer-readable storage medium described in this embodiment stores a computer program, and when the computer program is executed by a processor, the steps of a spacecraft preset time preset accuracy attitude tracking control method based on a performance function as described in any one of embodiments 1 to 7 are executed.

[0098] Implementation Method 11: See Figures 3 to 5 This embodiment provides a specific example of a spacecraft preset time preset accuracy attitude tracking control method based on a performance function described in the first embodiment, and is also used to explain the second to seventh embodiments, specifically:

[0099] This embodiment proposes a preset time and preset accuracy attitude tracking control method for spacecraft. Modified Rodriguez parameters (MRPs) are selected to describe the attitude of the spacecraft. First, a new performance function is designed, and the attitude tracking error under the MRPs expression is mathematically transformed to ensure that the initial condition of the attitude tracking error can be within the area defined by the performance function. Then, based on this performance function, considering the disturbances to the spacecraft, an adaptive preset time and preset accuracy attitude tracking control algorithm is designed.

[0100] Using MRPs to represent the attitude of the spacecraft, the attitude dynamics model of the spacecraft is:

[0101]

[0102] Among them, σ∈R 3 is the spacecraft attitude expressed in MRPs, ω∈R 3 is the angular velocity of the spacecraft, J∈R 3×3 is the moment of inertia matrix of the spacecraft relative to its center of mass, τ∈R 3 is the control input applied by the actuator, d∈R 3 is the disturbance torque.

[0103] Let the target posture be σ d (t), the corresponding target angular velocity is ω d (t), the attitude tracking error and angular velocity tracking error are:

[0104]

[0105] ω e =ω-C qe ω d (4)

[0106] in, represents the rotation matrix from the target body coordinate system to the actual body coordinate system, ω d is the target angular velocity ω d (t); σ d is the target posture σ d (t), σ is the aforementioned spacecraft attitude, is d (t) The corresponding cross product matrix:

[0107]

[0108] Among them, σ d1 , σ d2 , σ d3 is the vector σ d The three components of

[0109] The error posture dynamics model is:

[0110]

[0111] in, is the time rate of change of attitude tracking error; T(σ e ) is the error attitude kinematic matrix; is the time rate of change of angular velocity tracking error; f is an intermediate variable; is e The corresponding cross product matrix:

[0112]

[0113] Among them, σ e1 , σ e2 , σ e3 is the vector σ e The three components.

[0114] in:

[0115]

[0116] Define intermediate variables:

[0117]

[0118] Among them, arctan(.) is the inverse tangent function. Obviously, The time derivative of is:

[0119]

[0120] Define the performance function:

[0121]

[0122] Among them, β(t) is the performance function defined, T p is the preset time constant, t is the time variable, and ε is a positive constant.

[0123] Further define intermediate variables:

[0124]

[0125] but The time derivative of is:

[0126]

[0127] in:

[0128]

[0129] Next, construct a backstep variable:

[0130]

[0131] where g 0 > 0. On this basis, the continuous non-singular adaptive attitude tracking controller is constructed as follows:

[0132]

[0133] Where, τ is the control torque; S T (σ e ) is the matrix S(σ e ) can be called the intermediate variable; Θ is an intermediate variable; is an adaptive parameter; a is a positive constant, K 0 ∈R 3×3 is a symmetric positive definite matrix. The meaning of the operator L(.) is: for any three-dimensional column vector v = [v 1 ,v 2 ,v 3 ] T ∈R 3 ,have:

[0134]

[0135] and They satisfy the following adaptive rules respectively:

[0136]

[0137] Where c, g 1 and g 2 is a positive constant, K 1 ∈R 6×6 is a symmetric positive definite matrix.

[0138] Under any disturbance, the controller (14) can achieve the preset time and preset accuracy attitude tracking control of the spacecraft, that is, the attitude tracking error σ e The three components of will be at t≥T p , and the time is kept within the interval (-ε,ε).

[0139] The above control method is designed based on the attitude dynamics model of a rigid spacecraft. In fact, for a flexible spacecraft, the coupling torque generated by the vibration of the flexible attachment can be regarded as part of the disturbance, and the control method is still applicable.

[0140] The method described in this embodiment can ensure that the attitude value of the spacecraft converges to the expected attitude value within a preset time and with a preset accuracy after receiving the attitude tracking instruction. The preset time and the preset accuracy can be specified by the space mission. Compared with the existing preset time and preset accuracy attitude control method, this method does not need to predict the upper limit of the disturbance torque in advance, does not have a singularity problem, and the initial attitude error can be any value, and it is not required to be within a certain range near zero.

[0141] The present embodiment is verified by numerical simulation. The numerical simulation problem, simulation design process and simulation results are described as follows as an embodiment and technical proof of the present invention.

[0142] The moment of inertia of the spacecraft is:

[0143]

[0144] The target attitude trajectory is taken as

[0145] The external disturbance torque is set to d = 0.5[sin(t), cos(t), sin(0.5t)] T Nm.

[0146] The preset time constant is selected as T p =100s, and the preset accuracy constant is ε=0.0005.

[0147] Other controller parameters are selected as follows: K 0 =2I 3 , K 1 =I 6 , g 1 =g2 =0.002, a=0.0001. variable and The initial values ​​of and The initial posture is set to σ(0) = [-1, 2, -1.2] T , angular velocity is set to ω(0) = [-0.06, 0.05, 0.1] T rad / s.

[0148] Based on the above-set conditions, the following simulation was performed.

[0149] Under the above conditions, the simulation results are as follows: Figure 3 to Figure 5 shown. Figure 3 , Figure 4 The following are the response curves of attitude tracking error and angular velocity tracking error between 0 and 200 seconds. It can be seen that the tracking error of the spacecraft attitude to the expected trajectory converges to the preset accuracy within the preset time, and the actual convergence time is significantly shorter than the preset value T p =100s, attitude tracking error σ e The actual convergence accuracy of the three components is significantly better than the preset value ε=0.0005. Figure 5 The figure shows the control torque applied to the spacecraft body during this process. It can be seen that the control torque is continuous, which is in line with expectations.

[0150] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0151] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram and the combination of processes and / or blocks in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the process in the flowchart. Figure 1 A process or multiple processes and / or boxes Figure 1These computer program instructions can also be stored in a computer-readable memory that can guide a computer or other programmable data processing device to work in a specific way, so that the instructions stored in the computer-readable memory produce a product including an instruction device, which implements the functions specified in the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0152] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0153] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit its protection scope. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that after reading the present invention, those skilled in the art can still make various changes, modifications or equivalent substitutions to the specific implementation methods of the invention, but these changes, modifications or equivalent substitutions are all within the protection scope of the pending claims of the invention.

Claims

1. A spacecraft preset time preset accuracy attitude tracking control method based on performance function, characterized in that: The method comprises: S1: Construct the attitude dynamics model of the spacecraft based on the modified Rodriguez parameters MRPs; S2: Design performance functions and mathematically transform attitude tracking errors in the attitude dynamics model of the spacecraft; S3: Construct a continuous non-singular adaptive attitude tracking controller; S4: Implementing attitude tracking control of the spacecraft with a preset time and preset accuracy based on a continuous non-singular adaptive attitude tracking controller.

2. The method for controlling posture tracking with preset time and preset accuracy according to claim 1, characterized in that: The step S1 comprises: Among them, σ∈R 3 is the spacecraft attitude expressed in MRPs, ω∈R 3 is the angular velocity of the spacecraft, J∈R 3×3 is the moment of inertia matrix of the spacecraft relative to its center of mass, τ∈R 3 is the control input applied by the actuator, d∈R 3 is the disturbance torque.

3. The method for tracking and controlling a posture with a preset time and preset accuracy according to claim 1, characterized in that: The step S2 comprises: The error posture dynamics model is: in, is the time rate of change of attitude tracking error, T(σ e ) is the error attitude kinematic matrix, ω e is the angular velocity tracking error, σ e is the posture tracking error, is the time rate of change of angular velocity tracking error, and f is the intermediate variable; Design performance function: Among them, β(t) is the performance function, T p is the preset time constant, t is the time variable, and ε is a positive constant.

4. The method for tracking and controlling a posture with a preset time and a preset accuracy according to claim 3, characterized in that: The posture tracking error is specifically: Among them, σ d For the target posture, is the target posture σ d (t) The corresponding cross product matrix.

5. The method for controlling posture tracking with preset time and preset accuracy according to claim 3, characterized in that: The angular velocity tracking error is specifically: oh e =ω-C qe oh d Among them, C qe is the rotation matrix from the target body coordinate system to the actual body coordinate system, ω d is the target angular velocity.

6. The method for adaptive posture tracking control with preset time and preset accuracy according to claim 1, characterized in that: The step S3 comprises: Where τ is the control torque, S T (σ e ) is the intermediate variable matrix S(σ e ), Θ is the intermediate variable, is the intermediate variable, is the adaptive parameter, is an adaptive parameter, and K0 is a symmetric positive definite matrix.

7. The method for tracking and controlling a posture with a preset time and a preset accuracy according to claim 1, characterized in that: The step S4 comprises: Among them, h is an intermediate variable, s is an intermediate variable, K1 is a symmetric positive definite matrix, and c, g1 and g2 are positive constants.

8. A spacecraft preset time preset accuracy attitude tracking control system based on performance function, characterized in that: The system comprises: an onboard computer, an actuator, a spacecraft body, an onboard attitude sensor and an onboard angular velocity sensor; the onboard computer stores the tracking control method according to claim 1; The onboard computer generates control signals based on the expected and current attitude of the spacecraft; The control signal is used to drive the actuator to generate control torque; The actuator applies torque to the spacecraft body, thereby changing the spacecraft attitude and angular velocity; The onboard attitude sensor and onboard angular velocity sensor capture the spacecraft attitude and angular velocity information and feed the data back to the onboard computer; After receiving the feedback signal, the onboard computer compares it with the desired attitude and adjusts the control signal again based on the deviation to ensure that the spacecraft can reach or maintain the desired attitude.

9. A computer device, characterized in that: It comprises a memory and a processor, wherein a computer program is stored in the memory, and when the processor runs the computer program stored in the memory, the processor executes a spacecraft preset time preset accuracy attitude tracking control method based on a performance function according to any one of claims 1-7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, which, when executed by a processor, executes the steps of a spacecraft preset time preset accuracy attitude tracking control method based on a performance function as described in any one of claims 1-7.

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