An on-orbit satellite attitude guaranteeing performance control method, system and device

Abstract

This invention discloses an on-orbit satellite attitude performance-preserving control method, system, and device, relating to the field of spacecraft control technology. Addressing the difficulty of quantitatively designing and guaranteeing system transient performance using existing methods, this invention establishes an on-orbit satellite attitude dynamics model based on modified Rodriguez parameters; designs auxiliary variables for the on-orbit satellite attitude dynamics model based on attitude tracking error and its derivative, and imposes performance constraints on these auxiliary variables; transforms the performance-constrained auxiliary variables into unconstrained state variables through error transformation; and designs an on-orbit satellite attitude performance-preserving controller based on the unconstrained state variables. This invention enables the on-orbit satellite attitude tracking error to be strictly constrained within pre-defined performance boundaries, thereby achieving precise quantitative control of the attitude dynamic process.

Description

Technical Field

[0001] This invention relates to the field of spacecraft control technology, and in particular to an on-orbit satellite attitude maintenance control method, system and device. Background Technology

[0002] Satellite attitude control is one of the key technologies for ensuring the normal operation and mission completion of satellites. While traditional satellite attitude controllers (such as proportional-derivative control) can guarantee stability, they struggle to precisely and quantitatively design and guarantee transient and steady-state performance indicators such as overshoot, convergence rate, and steady-state accuracy. In high-performance Earth observation, rapid maneuvering, and target tracking missions, the dynamic process of attitude control has stringent requirements, demanding that the controller not only stabilize the system but also ensure that the dynamic response meets pre-set performance indicators. However, existing satellite attitude control methods still have significant shortcomings: traditional proportional-derivative control (PD control) relies on empirical parameter tuning and cannot explicitly and quantitatively design performance indicators such as overshoot, convergence rate, and steady-state accuracy; sliding mode control, While robust control methods offer some protection against uncertainties and external disturbances, their control laws are complex and transient performance remains difficult to guarantee in advance. Adaptive control methods often experience significant transient fluctuations during parameter convergence, making it challenging to ensure that attitude errors remain within acceptable ranges throughout the transient process. Furthermore, commonly used attitude parameters exhibit singular or dual-value problems during large-angle maneuvers, further complicating performance constraint design. Therefore, designing an attitude control method that can be directly quantified and guarantees both transient and steady-state performance is of significant engineering importance. Summary of the Invention

[0003] To address the aforementioned problems, this invention aims to provide an on-orbit satellite attitude performance control method, system, and device. Based on a preset performance control theory, it defines the convergence envelope of attitude error by designing an exponentially decaying performance function, and uses error transformation to convert the performance-constrained controlled object to an unconstrained design dimension for controller design. This ensures that the on-orbit satellite attitude tracking error is strictly constrained within a pre-set performance boundary, thereby achieving precise quantitative control of the attitude dynamic process.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] On one hand, the present invention provides an on-orbit satellite attitude maintenance control method, the method comprising:

[0006] Establish an on-orbit satellite attitude dynamics model based on modified Rodriguez parameters;

[0007] Based on attitude tracking error and its derivative, auxiliary variables for the on-orbit satellite attitude dynamics model are designed, and performance constraints are imposed on the auxiliary variables.

[0008] The performance-constrained auxiliary variables are transformed into state variables in an unconstrained space through error transformation;

[0009] Based on the state variables of the unconstrained space, an on-orbit satellite attitude preservation controller is designed.

[0010] Optionally, establishing an on-orbit satellite attitude dynamics model based on modified Rodriguez parameters includes:

[0011] The attitude of the satellite in orbit is described by the modified Rodriguez parameter. An attitude dynamic equation that includes model uncertainty and external disturbance is established and the attitude dynamic equation is converted into the Euler-Lagrange system form.

[0012] Optionally, the attitude dynamics equations can be expressed in Euler-Lagrange system form as follows:

[0013]

[0014] In the formula, This represents the attitude parameters of a satellite in orbit. This represents the rate of attitude change of an on-orbit satellite. This represents the attitude acceleration of a satellite in orbit. Representation and attitude parameters The relevant generalized inertia matrix, Representation and attitude parameters and attitude change rate The relevant generalized Coriolis and centripetal matrix, Indicates equivalent input. This represents an equivalent unknown disturbance.

[0015] Optionally, the step of designing auxiliary variables for the on-orbit satellite attitude dynamics model based on attitude tracking error and its derivative, and imposing performance constraints on the auxiliary variables, includes:

[0016] Construct an auxiliary variable consisting of a linear combination of the derivatives of the attitude error and the attitude tracking error;

[0017] A time-varying constraint boundary for auxiliary variables is constructed using an exponentially decaying preset performance function. This time-varying constraint boundary is used to constrain the maximum overshoot, minimum convergence rate, and steady-state accuracy of the on-orbit satellite.

[0018] Optionally, the step of converting performance-constrained auxiliary variables into state variables in an unconstrained space through error transformation includes:

[0019] The performance-constrained auxiliary variables are mapped to the unconstrained space through a mapping function, and the state variables of the unconstrained space are defined.

[0020] The mapping function is differentiated to establish a dynamic relationship between the performance-constrained auxiliary variables and the unconstrained space state variables.

[0021] Optionally, the formula for the performance-preserving controller is expressed as:

[0022]

[0023] In the formula, Indicates the control input torque. Let Jacobian matrix be the one derived from the error transformation. Represents the state variables in an unconstrained space. Representing the state quantities in the unconstrained space A time-dependent positive definite diagonal weighted matrix. This indicates the positive real control gain that needs to be designed. This represents a positive definite diagonal matrix.

[0024] On the other hand, the present invention also provides an on-orbit satellite attitude maintenance control system, comprising:

[0025] The modeling module is used to build on-orbit satellite attitude dynamics models;

[0026] The performance constraint module is used to apply performance constraints to the auxiliary variables of the on-orbit satellite attitude dynamics model;

[0027] The error transformation module is used to convert performance-constrained auxiliary variables into state variables in an unconstrained space.

[0028] The controller module is used to design an on-orbit satellite attitude maintenance controller;

[0029] Among them, the modeling module, performance constraint module, error transformation module and controller module are implemented based on the on-orbit satellite attitude performance preservation control method described above.

[0030] In another aspect, the present invention also provides an electronic device, including at least one processor; and a memory communicatively connected to the processor; wherein the memory stores instructions executed by the processor to enable the processor to perform the on-orbit satellite attitude maintenance control method as described above.

[0031] The beneficial effects of this invention are:

[0032] (1) This invention allows designers to directly and quantitatively specify the maximum overshoot, minimum convergence rate and steady-state accuracy of the attitude control system, thus realizing customized design of control quality.

[0033] (2) This invention has a good suppression effect on model uncertainty and external disturbances through performance constraints and robust control term design, thus enhancing the robustness of the system.

[0034] (3) The control method of the present invention does not depend on an exact model, has a clear framework, and can be combined with other advanced control theories (such as adaptive control and fuzzy control) to further expand its application scope.

[0035] (4) The controller structure designed in this invention is relatively simple, has a low computational burden, and is easy to implement on a spaceborne computer, providing an effective solution for high-precision on-orbit satellite attitude control. Attached Figure Description

[0036] Figure 1 This is a flowchart of the on-orbit satellite attitude maintenance control method of the present invention.

[0037] Figure 2 This is a schematic diagram of the preset performance control method in this invention.

[0038] Figure 3 This is a schematic diagram illustrating the changes in auxiliary variables under the pre-defined performance function constraints in this invention.

[0039] Figure 4 The results are simulations of the on-orbit satellites used in this invention. Detailed Implementation

[0040] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention will be further described below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only a part of the embodiments, and not all of the embodiments.

[0041] Example 1:

[0042] Example 1 provides an on-orbit satellite attitude maintenance control method, as shown in the attached figure. Figure 1 As shown, the method specifically includes the following steps:

[0043] Step 1: Establish an on-orbit satellite attitude dynamics model based on modified Rodriguez parameters;

[0044] The attitude dynamics model of the on-orbit satellite is chosen to be based on the Modified Rodrigues parameter (MRP). MRP is a non-singular parameter describing three-dimensional attitude, and its definition is as follows:

[0045] (1)

[0046] In the formula, Indicates the transient Euler axis. Represents transient Euler angles. This refers to MRP, which stands for attitude parameters of an in-orbit satellite.

[0047] The kinematic equations of attitude of an on-orbit satellite based on MRP are expressed as follows:

[0048] (2)

[0049] In the formula, The attitude change rate of the satellite in orbit. The angular velocity of the satellite in orbit. The attitude kinematics matrix is ​​composed of attitude parameters. Decide, It is a third-order identity matrix.

[0050] For any vector , operator A third-order skew-symmetric matrix is ​​represented as:

[0051] (3)

[0052] The attitude dynamics equations of a rigid on-orbit satellite are expressed as follows:

[0053] (4)

[0054] In the formula, angular velocity rate of change, Let be the symmetric positive definite inertial matrix of the satellite in orbit. and These are control input and unknown interference, respectively.

[0055] To facilitate controller design, the attitude kinematics equation described in formula (2) is differentiated using differential algebra, and the attitude dynamics equation described in formula (4) is substituted into the equation, and the equations are simultaneously transformed into Euler-Lagrange form:

[0056] (5)

[0057] In the formula, This represents the attitude acceleration of a satellite in orbit. Representation and attitude parameters The relevant generalized inertia matrix, Representation and attitude parameters and attitude change rate The relevant generalized Coriolis and centripetal matrix, Indicates equivalent input. This represents an equivalent unknown disturbance.

[0058] Step 2: Based on the attitude tracking error and its derivative, design auxiliary variables for the on-orbit satellite attitude dynamics model, and impose performance constraints on the auxiliary variables;

[0059] Define attitude tracking error ,in This represents the reference target value for attitude control of the satellite in orbit. The control objective is to ensure that the attitude tracking error is maintained. and its differential The system should be able to converge to the acceptable range, and its transient and stability performance should be guaranteed during the convergence process. To achieve this, auxiliary variables are designed. , is represented as:

[0060] (6)

[0061] In the formula, This represents the positive definite diagonal gain matrix, specifically expressed as: , The weighting coefficients correspond to the three attitude axes of the satellite in orbit, and require... .

[0062] The principle of Preset Performance Control (PPC) is as follows: Figure 2 As shown. This invention is based on a preset performance control method, which controls auxiliary variables. Apply the following time-varying performance constraints:

[0063] (7)

[0064] In the formula, It is a constant and satisfies This is used to reduce system overshoot. The preset performance function (PPF) typically satisfies: (a) for , And its derivative (b) .

[0065] Designing the PPF as exponentially convergent is expressed as:

[0066] (8)

[0067] In the formula, Describe the initial value of PPF and satisfy the following conditions: , This represents the final value of PPF. The convergence exponent determines the convergence speed.

[0068] To simplify the representation, constants are introduced. and Equation (7) can be equivalently expressed as:

[0069] (9)

[0070] In the formula, , .

[0071] Step 3: Transform the performance-constrained auxiliary variables into state variables in an unconstrained space through error transformation;

[0072] Appendix Figure 3 This demonstrates the effect under PPF constraints. The changes are confined within a time-varying boundary. For the initial values ​​in both cases, the performance boundary ensures that the controlled state variable remains within the envelope, by introducing a mapping function. The controlled state variables are mapped one-to-one from the constrained space to the unconstrained space, expressed as:

[0073] (10)

[0074] Mapping function It has a local first-order Lipschitz derivative in the domain. The internal property satisfies the characteristic of monotonically increasing. , .

[0075] Define the controlled state variables in an unconstrained space (or simply unconstrained space state variables) as follows: , is represented as:

[0076] (11)

[0077] This transformation changes the variables within the constraint space. Transform into state variables in unconstrained space .when In unconstrained space When there is a bounded interval, the corresponding It must be in the range Internally, thus ensuring Performance constraints are met.

[0078] To ensure Given the boundedness of the equation, taking the derivative of formula (11) yields the transformed dynamic relationship:

[0079] (12)

[0080] In the formula, Defined as , .

[0081] Step 4: Design an on-orbit satellite attitude control system based on the state variables of the unconstrained space to ensure that the attitude tracking error meets the preset transient and steady-state performance requirements.

[0082] Specifically, based on the original nonlinear system, the Euler-Lagrange system, and the unconstrained space state variables... Based on the analysis, a performance-preserving controller is designed, expressed as:

[0083] (13)

[0084] In the formula, To control the input torque, used to adjust the attitude of the satellite in orbit; Let be the Jacobian matrix derived from the error transformation; For unconstrained space state quantities A time-dependent positive definite diagonal weighted matrix; The required positive real control gain; It is a positive definite diagonal matrix used to adjust the control weights of the three attitude axes.

[0085] Positive definite diagonal matrix The following constraints must be met:

[0086] (14)

[0087] In the formula, Represents the controlled state variables in an unconstrained space. The initial value.

[0088] This constraint As an initial feasibility condition, the initial state of the system must satisfy the performance boundary to ensure that the error transformation is within the effective domain at the initial moment, thereby ensuring that the performance constraints always hold during the subsequent control process.

[0089] By selecting appropriate parameters, this controller can guarantee unconstrained variables. Bounded, thus ensuring the original auxiliary variable The preset performance constraints are always met, and the attitude tracking error is eventually converged according to the predetermined performance indicators.

[0090] Example 2:

[0091] This embodiment demonstrates a specific case study of the on-orbit satellite attitude maintenance control method described in Embodiment 1.

[0092] Attitude maneuver control simulation was performed for a low-Earth orbit remote sensing satellite. The initial attitude, desired attitude, orbital parameters, and controller parameters of the satellite in orbit were set, as shown in Table 1 below. A performance-preserving controller based on preset performance control was used for simulation, and the results are attached. Figure 4 As shown in the figure. Simulation results show that the attitude tracking error of the on-orbit satellite is always constrained within the preset performance function envelope and converges rapidly to the desired steady-state accuracy range; the angular velocity of the on-orbit satellite also converges smoothly, and the control torque is continuously bounded.

[0093] Table 1. On-orbit satellite parameter settings

[0094]

[0095] Example 3:

[0096] Example 3 provides an on-orbit satellite attitude maintenance control system, including a modeling module, a performance constraint module, an error transformation module, and a controller module;

[0097] The modeling module is used to build on-orbit satellite attitude dynamics models;

[0098] The performance constraint module is used to apply performance constraints to the auxiliary variables of the on-orbit satellite attitude dynamics model;

[0099] The error transformation module is used to convert performance-constrained auxiliary variables into state variables in an unconstrained space.

[0100] The controller module is used to design an on-orbit satellite attitude maintenance controller;

[0101] The modeling module, performance constraint module, error transformation module, and controller module are implemented based on the on-orbit satellite attitude maintenance control method described in Example 1.

[0102] Example 4:

[0103] Embodiment 4 provides an electronic device, including at least one processor; and a memory communicatively connected to the processor; wherein the memory stores instructions that are executed by the processor, the instructions being executed by the processor to enable the processor to perform the on-orbit satellite attitude maintenance control method described in Embodiment 1.

[0104] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. An on-orbit satellite attitude maintenance control method, characterized in that, The method includes: Establish an on-orbit satellite attitude dynamics model based on modified Rodriguez parameters; Based on attitude tracking error and its derivative, auxiliary variables for the on-orbit satellite attitude dynamics model are designed, and performance constraints are imposed on the auxiliary variables. The performance-constrained auxiliary variables are transformed into state variables in an unconstrained space through error transformation; Based on the state variables of the unconstrained space, an on-orbit satellite attitude preservation controller is designed.

2. The on-orbit satellite attitude maintenance control method according to claim 1, characterized in that, The establishment of the on-orbit satellite attitude dynamics model based on the modified Rodriguez parameters includes: The attitude of the satellite in orbit is described by the modified Rodriguez parameter. An attitude dynamic equation that includes model uncertainty and external disturbance is established and the attitude dynamic equation is converted into the Euler-Lagrange system form.

3. The on-orbit satellite attitude maintenance control method according to claim 2, characterized in that, The attitude dynamics equations are expressed in Euler-Lagrange system form as follows: ； In the formula, This represents the attitude parameters of a satellite in orbit. This represents the rate of attitude change of an on-orbit satellite. This represents the attitude acceleration of a satellite in orbit. Representation and attitude parameters The relevant generalized inertia matrix, Representation and attitude parameters and attitude change rate The relevant generalized Coriolis and centripetal matrix, Indicates equivalent input. This represents an equivalent unknown disturbance.

4. The on-orbit satellite attitude maintenance control method according to claim 3, characterized in that, The auxiliary variables for the on-orbit satellite attitude dynamics model are designed based on attitude tracking error and its derivative, and performance constraints are imposed on the auxiliary variables, including: Construct an auxiliary variable consisting of a linear combination of the derivatives of the attitude error and the attitude tracking error; A time-varying constraint boundary for auxiliary variables is constructed using an exponentially decaying preset performance function. This time-varying constraint boundary is used to constrain the maximum overshoot, minimum convergence rate, and steady-state accuracy of the on-orbit satellite.

5. The on-orbit satellite attitude maintenance control method according to claim 4, characterized in that, The process of converting performance-constrained auxiliary variables into state variables in an unconstrained space through error transformation includes: The performance-constrained auxiliary variables are mapped to the unconstrained space through a mapping function, and the state variables of the unconstrained space are defined. The mapping function is differentiated to establish a dynamic relationship between the performance-constrained auxiliary variables and the unconstrained space state variables.

6. The on-orbit satellite attitude maintenance control method according to claim 5, characterized in that, The formula for the performance-preserving controller is expressed as follows: ； In the formula, Indicates the control input torque. Let Jacobian matrix be the one derived from the error transformation. Represents the state variables in an unconstrained space. Representing the state quantities in the unconstrained space A time-dependent positive definite diagonal weighted matrix. This indicates the positive real control gain that needs to be designed. This represents a positive definite diagonal matrix.

7. An on-orbit satellite attitude maintenance control system, characterized in that, include: The modeling module is used to build on-orbit satellite attitude dynamics models; The performance constraint module is used to apply performance constraints to the auxiliary variables of the on-orbit satellite attitude dynamics model; The error transformation module is used to convert performance-constrained auxiliary variables into state variables in an unconstrained space. The controller module is used to design an on-orbit satellite attitude maintenance controller; The modeling module, performance constraint module, error transformation module, and controller module are implemented based on the on-orbit satellite attitude maintenance control method described in any one of claims 1-6.

8. An electronic device, characterized in that, It includes at least one processor; and a memory communicatively connected to the processor; wherein the memory stores instructions that are executed by the processor to enable the processor to perform the on-orbit satellite attitude maintenance control method according to any one of claims 1-6.

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