A spacecraft attitude-orbit-vibration coupled control method based on non-fragile disturbance observer

Abstract

The present invention discloses a spacecraft attitude, orbit and vibration coupling control method based on a non-fragile disturbance observer, including the following steps: S1, establishing a spacecraft orbit-attitude-vibration coupling dynamics model, and converting it into a classical nonlinear system form; S2, for the interference terms existing in the spacecraft orbit-attitude-vibration coupling dynamics model in the classical nonlinear system form, by introducing an auxiliary dynamics system, under the condition of observer gain perturbation, a non-fragile superhelical disturbance observer is designed; S3, constructing a control Lyapunov function, and then designing a robust inverse optimal controller based on disturbance information; S4, substituting the robust inverse optimal controller into the spacecraft closed-loop dynamics system, so that the orbit, attitude and vibration of the spacecraft reach a stable state, and realizing coupling control. The present invention can realize orbit-attitude-vibration stable control under the coexistence of external disturbance and observer gain disturbance, with low control energy consumption and high precision, and a wide range of applications.

Description

Technical Field

[0001] The invention belongs to the field of spacecraft coupling control, and in particular relates to a spacecraft attitude, orbit and vibration coupling control method based on a non-fragile interference observer. Background Art

[0002] Traditional spacecraft control systems focus primarily on independent control of orbit, attitude, and vibration degrees of freedom, which can degrade the accuracy of the model and impair system performance.

[0003] Existing research on spacecraft coupling control mainly focuses on two aspects: one is orbit-attitude coupling control, which mainly uses dual quaternion or SE (3) Lie algebra method to achieve stable control of spacecraft, but this type of method is suitable for rigid spacecraft without vibration effect; the other is attitude-vibration coupling control, which mainly realizes stable control of attitude and vibration for flexible spacecraft without considering the influence of orbit coupling effect. The spacecraft coupling integrated control method that considers orbit, attitude and vibration dynamics at the same time is still in the development stage. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the spacecraft attitude, orbit and vibration coupling control method based on a non-fragile disturbance observer provided by the present invention solves the inverse optimal control problem of spacecraft orbit-attitude-vibration coupling under the action of external disturbances and observer gain perturbations, realizes high-precision and high-stability control of the closed-loop system, lowers control energy consumption, and further improves control efficiency.

[0005] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is: a spacecraft attitude orbit vibration coupling control method based on a non-fragile disturbance observer, comprising the following steps:

[0006] S1. Establish the spacecraft orbit-attitude-vibration coupled dynamic model and transform it into a classical nonlinear system form;

[0007] S2. Aiming at the interference terms existing in the spacecraft orbit-attitude-vibration coupled dynamic model in the form of a classical nonlinear system, a non-fragile superhelical interference observer is designed by introducing an auxiliary dynamic system under the condition of observer gain perturbation.

[0008] S3, construct the control Lyapunov function, and then design the robust inverse optimal controller based on the disturbance information;

[0009] The disturbance information is estimated and reconstructed according to the non-fragile superhelical disturbance observer and compensated in the robust inverse optimal controller.

[0010] S4. Substitute the robust inverse optimal controller into the closed-loop dynamic system of the spacecraft to make the orbit, attitude and vibration of the spacecraft reach a stable state and realize coupled control.

[0011] Furthermore, in step S1, the spacecraft-orbit-attitude coupling dynamics model expression is:

[0012]

[0013] In the formula, represents the mass of the spacecraft, and denote the orbit-vibration coupling coefficient matrix and attitude-vibration coupling coefficient matrix respectively, represents the orbit control force, is the spacecraft moment of inertia, represents the attitude control torque, and They represent orbital external disturbance and attitude external disturbance respectively, represents the damping coefficient matrix, represents the stiffness coefficient matrix, the superscript T represents the transposition operator, represents the orbital velocity vector, represents the first derivative of the orbital velocity example, represents the attitude angular velocity vector, represents the first-order derivative of the attitude velocity vector, represents the vibration mode coordinates, represents the first-order derivative of the vibration modal coordinates, Represents the second derivative of the vibration modal coordinates.

[0014] Furthermore, the classical nonlinear system form of the spacecraft orbit-attitude vibration coupling dynamics model is:

[0015]

[0016] In the formula, represents the auxiliary variable vector, f ( x ) represents the nonlinear term of the system, represents the system state variable, represents the orbital motion position vector, represents the attitude motion angle vector, represents the vibration mode coordinates, represents the attitude angular velocity vector, represents the first-order derivative of the vibration modal coordinates, g represents the input coefficient matrix, represents the control input, represents the interference vector, , .

[0017] Furthermore, in step S2, the auxiliary dynamics system introduced is expressed as:

[0018]

[0019] In the formula, Represents the auxiliary variable vector introduced, when and When approaching, the estimation of the real interference is achieved, f ( x ) represents the nonlinear term of the system, represents the system state variable, represents the orbital motion position vector, represents the attitude motion angle vector, represents the vibration mode coordinates, represents the attitude angular velocity vector, represents the first-order derivative of the vibration modal coordinates, g represents the input coefficient matrix, represents the control input, represents the interference vector, , .

[0020] Furthermore, in step S2, the designed non-fragile superhelical interference observer is expressed as:

[0021]

[0022] In the formula, represents the estimated value of interference, represents auxiliary variables, express The pseudo-inverse matrix of represents the system state variable, represents the auxiliary variable vector introduced, represents the input coefficient matrix, represents the additional variables introduced, express The first derivative of represents the symbolic function, and They represent the observer gain perturbation terms respectively.

[0023] Furthermore, in step S3, the control Lyapunov function is expressed as V for:

[0024]

[0025] In the formula, , and represents the position level coefficient, , and Respectively represent the speed level coefficient, , and They represent the coupling coefficient, represents the orbital motion position vector, represents the attitude motion angle vector, represents the vibration mode coordinates, represents the orbital velocity vector, represents the attitude angular velocity vector, represents the first-order derivative of the vibration mode coordinates; where, Satisfy the conditions , .

[0026] Furthermore, in step S3, the designed robust inverse optimal controller is expressed as:

[0027]

[0028]

[0029]

[0030] In the formula, represents the control input, represents the nominal control input, represents the interference estimate, , , represents the designable coefficient matrix.

[0031] The beneficial effects of the present invention are:

[0032] (1) The present invention proposes a spacecraft attitude, orbit and vibration coupling control method based on a non-fragile disturbance observer, which can achieve orbit-attitude-vibration stability control under the coexistence of external disturbances and observer gain disturbances, with low control energy consumption and high precision.

[0033] (2) The present invention has a wide range of applications. It can be applied not only to the attitude-orbit-vibration coupling control of traditional flexible spacecraft, but also to the integrated stability control of the on-orbit construction of future ultra-large space infrastructure. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a flow chart of the spacecraft attitude-orbit-vibration coupling control method based on non-fragile disturbance observer.

[0035] Figure 2 is the track displacement variation curve, Rx , R y and R z It represents the displacement change of three axes, and m represents the displacement in meters.

[0036] Figure 3 is the attitude angle change curve, θ x , θ y and θ z Indicates the change in the three-axis attitude angle, and rad indicates that the unit of the angle is radian.

[0037] Figure 4 is the modal coordinate change curve, η 1, η 2, η 3. η 4. η 5 represents the change of modal coordinates. DETAILED DESCRIPTION

[0038] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0039] The embodiment of the present invention provides a spacecraft attitude-orbit-vibration coupling control method based on a non-fragile disturbance observer, such as Figure 1 As shown, the following steps are included:

[0040] S1. Establish the spacecraft orbit-attitude-vibration coupled dynamic model and transform it into a classical nonlinear system form;

[0041] S2. Aiming at the interference terms existing in the spacecraft orbit-attitude-vibration coupled dynamic model in the form of a classical nonlinear system, a non-fragile superhelical interference observer is designed by introducing an auxiliary dynamic system under the condition of observer gain perturbation.

[0042] S3, construct the control Lyapunov function, and then design the robust inverse optimal controller based on the disturbance information;

[0043] The disturbance information is estimated and reconstructed according to the non-fragile superhelical disturbance observer and compensated in the robust inverse optimal controller.

[0044] S4. Substitute the robust inverse optimal controller into the closed-loop dynamic system of the spacecraft to make the orbit, attitude and vibration of the spacecraft reach a stable state and realize coupled control.

[0045] In step S1 of the embodiment of the present invention, the spacecraft-orbit-attitude coupling dynamics model expression is:

[0046]

[0047] In the formula, represents the mass of the spacecraft, and denote the orbit-vibration coupling coefficient matrix and attitude-vibration coupling coefficient matrix respectively, represents the orbit control force, is the spacecraft moment of inertia, represents the attitude control torque, and They represent orbital external disturbance and attitude external disturbance respectively, represents the damping coefficient matrix, represents the stiffness coefficient matrix, the superscript T represents the transposition operator, represents the orbital velocity vector, represents the first derivative of the orbital velocity example, represents the attitude angular velocity vector, represents the first-order derivative of the attitude velocity vector, represents the vibration mode coordinates, represents the first-order derivative of the vibration modal coordinates, Represents the second derivative of the vibration modal coordinates.

[0048] In this embodiment, the dynamic equivalent transformation method is used to transform it into a non-classical nonlinear system form; specifically, the system state vector is recorded as , the classical nonlinear system form of the spacecraft orbit-attitude vibration coupling dynamics model is obtained as:

[0049]

[0050] In the formula, represents the auxiliary variable vector, f ( x ) represents the nonlinear term of the system, represents the system state variable, represents the orbital motion position vector, represents the attitude motion angle vector, represents the vibration mode coordinates, represents the attitude angular velocity vector, represents the first-order derivative of the vibration modal coordinates, grepresents the input coefficient matrix, represents the control input, represents the interference vector, , .

[0051] In step S2 of the embodiment of the present invention, a non-winding superhelical interference observer is designed by considering the observer gain perturbation condition to achieve accurate estimation of external interference; specifically, the introduced auxiliary dynamics system is expressed as:

[0052]

[0053] In the formula, Represents the auxiliary variable vector introduced, when and When approaching, the estimation of the real interference is achieved, f ( x ) represents the nonlinear term of the system, represents the system state variable, represents the orbital motion position vector, represents the attitude motion angle vector, represents the vibration mode coordinates, represents the attitude angular velocity vector, represents the first-order derivative of the vibration modal coordinates, g represents the input coefficient matrix, represents the control input, represents the interference vector, , .

[0054] In step S2 of this embodiment, the designed non-fragile superhelical interference observer is expressed as:

[0055]

[0056] In the formula, represents the estimated value of interference, represents auxiliary variables, express The pseudo-inverse matrix of represents the system state variable, represents the auxiliary variable vector introduced, represents the input coefficient matrix, represents the additional variables introduced, express The first derivative of represents the symbolic function, and They represent the observer gain perturbation terms respectively.

[0057] Based on the above non-fragile superhelical disturbance observer, reconstruction of external disturbances can be achieved.

[0058] In step S3 of the embodiment of the present invention, the designed control Lyapunov function is expressed as V for:

[0059]

[0060] In the formula, , and represents the position level coefficient, , and Respectively represent the speed level coefficient, , and They represent the coupling coefficient, represents the orbital motion position vector, represents the attitude motion angle vector, represents the vibration mode coordinates, represents the orbital velocity vector, represents the attitude angular velocity vector, represents the first-order derivative of the vibration mode coordinates; where, Satisfy the conditions , .

[0061] Based on the designed control Lyapunov function, the designed robust inverse optimal controller is expressed as:

[0062]

[0063]

[0064]

[0065] In the formula, represents the control input, represents the nominal control input, represents the interference estimate, , , represents the designable coefficient matrix.

[0066] In step S4 of the embodiment of the present invention, the robust inverse optimal controller is substituted into the closed-loop dynamic system of the spacecraft to ensure that the orbit, attitude and vibration of the spacecraft reach a stable state, thereby effectively realizing the integrated control of the spacecraft orbit maintenance, attitude stabilization and vibration suppression.

[0067] In a specific example of the present invention, the control result obtained based on the above method is as follows: Figure 2-4As shown, Figure 2 represents the track displacement variation curve, Figure 3 Represents the attitude angle change curve, Figure 4 It represents the modal coordinate change curve, which shows that the control method has a good control effect.

[0068] It should be noted that the method of the present invention has a wide range of applications. It can be applied not only to the attitude, orbit and vibration coupling control of traditional flexible spacecraft, but also to the integrated stability control of the on-orbit construction of future super-large space infrastructure.

[0069] The present invention uses specific embodiments to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

[0070] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. A spacecraft attitude-orbit-vibration coupling control method based on a non-fragile disturbance observer, characterized in that: The following steps are involved: S1. Establish the spacecraft orbit-attitude-vibration coupled dynamic model and transform it into a classical nonlinear system form; S2. Aiming at the interference terms existing in the spacecraft orbit-attitude-vibration coupled dynamic model in the form of a classical nonlinear system, a non-fragile superhelical interference observer is designed by introducing an auxiliary dynamic system under the condition of observer gain perturbation. S3, construct the control Lyapunov function, and then design the robust inverse optimal controller based on the disturbance information; The disturbance information is estimated and reconstructed according to the non-fragile superhelical disturbance observer and compensated in the robust inverse optimal controller. S4, Substitute the robust inverse optimal controller into the closed-loop dynamic system of the spacecraft to make the orbit, attitude and vibration of the spacecraft reach a stable state and realize coupled control; In step S3, the control Lyapunov function is expressed as V for: In the formula, , and represents the position level coefficient, , and Respectively represent the speed level coefficient, , and They represent the coupling coefficient, represents the orbital motion position vector, represents the attitude motion angle vector, represents the vibration mode coordinates, represents the orbital velocity vector, represents the attitude angular velocity vector, represents the first-order derivative of the vibration mode coordinates; where, Satisfy the conditions , ; In step S3, the designed robust inverse optimal controller is expressed as: In the formula, represents the control input, represents the nominal control input, represents the interference estimate, , , represents the designable coefficient matrix.

2. The spacecraft attitude-orbit-vibration coupling control method based on a non-fragile disturbance observer according to claim 1 is characterized in that: In step S1, the spacecraft-orbit-attitude coupling dynamics model expression is: In the formula, represents the mass of the spacecraft, and denote the orbit-vibration coupling coefficient matrix and attitude-vibration coupling coefficient matrix respectively, represents the orbit control force, is the spacecraft moment of inertia, represents the attitude control torque, and They represent orbital external disturbance and attitude external disturbance respectively, represents the damping coefficient matrix, represents the stiffness coefficient matrix, the superscript T represents the transposition operator, represents the orbital velocity vector, represents the first derivative of the orbital velocity example, represents the attitude angular velocity vector, represents the first-order derivative of the attitude velocity vector, represents the vibration mode coordinates, represents the first-order derivative of the vibration modal coordinates, Represents the second derivative of the vibration modal coordinates.

3. The spacecraft attitude-orbit-vibration coupling control method based on non-fragile disturbance observer according to claim 2 is characterized in that: The classical nonlinear system form of the spacecraft orbit-attitude vibration coupling dynamics model is: In the formula, represents the auxiliary variable vector, f ( x ) represents the nonlinear term of the system, represents the system state variable, represents the orbital motion position vector, represents the attitude motion angle vector, represents the vibration mode coordinates, represents the attitude angular velocity vector, represents the first-order derivative of the vibration modal coordinates, g represents the input coefficient matrix, represents the control input, represents the interference vector, , .

4. The spacecraft attitude, orbit and vibration coupling control method based on non-fragile disturbance observer according to claim 1 is characterized in that: In step S2, the auxiliary dynamics system introduced is expressed as: In the formula, Represents the auxiliary variable vector introduced, when and When approaching, the estimation of the real interference is achieved, f ( x ) represents the nonlinear term of the system, represents the system state variable, represents the orbital motion position vector, represents the attitude motion angle vector, represents the vibration mode coordinates, represents the attitude angular velocity vector, represents the first-order derivative of the vibration modal coordinates, g represents the input coefficient matrix, represents the control input, represents the interference vector, , .

5. The spacecraft attitude-orbit-vibration coupling control method based on non-fragile disturbance observer according to claim 4 is characterized in that: In step S2, the designed non-fragile superhelical interference observer is expressed as: In the formula, represents the estimated value of interference, represents auxiliary variables, express The pseudo-inverse matrix of represents the system state variable, represents the auxiliary variable vector introduced, represents the input coefficient matrix, represents the additional variables introduced, express The first derivative of represents the symbolic function, and They represent the observer gain perturbation terms respectively.

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