A space platform takeover control method and system after on-orbit splicing

Abstract

The present invention discloses a method and system for controlling a takeover of a space platform after on-orbit splicing, and relates to the technical field of large modular space platforms. The method comprises: establishing a state-space model for attitude takeover control of the space platform after on-orbit splicing; the space platform after on-orbit splicing is a combination of multiple modular platforms; based on the state-space model for attitude takeover control, calculating a desired control torque for stabilizing the space platform after on-orbit splicing, and generating a desired control torque signal according to the desired control torque; distributing the desired control torque signal to each modular platform according to the communication topology relationship between the modular platforms in the space platform after on-orbit splicing and the real-time energy consumption of each modular platform; and controlling the actuators of each modular platform to generate corresponding control torques according to the sub-control torque signals distributed to each modular platform in real time. The present invention improves the control accuracy of the takeover of the space platform after on-orbit splicing.

Description

Technical Field

[0001] The present invention relates to the technical field of large modular space platforms, and in particular to a method and system for controlling a space platform after on-orbit splicing. Background Art

[0002] With the increasing difficulty of large-scale spacecraft development, the significant increase in support system resources, and the decrease in reusability, relevant countries and research institutions have begun to pursue modularization of space systems to standardize production and development processes, reduce costs, and improve system maintainability and upgradeability. Large-scale reconfigurable space platforms are a typical model for building large spacecraft. Large-scale reconfigurable space platforms are large spacecraft platforms composed of modular platforms connected according to specific rules, capable of changing their configuration according to space missions. These modular platforms feature standard interfaces, self-describing functional modules, and self-configuring systems.

[0003] During the on-orbit construction of large-scale reconfigurable space platforms, the configuration changes due to splicing and reconstruction. This change in inertial information also leads to numerous problems, including complex takeover controller design, low actuator coordination efficiency, uneven energy consumption between modules, and low control accuracy. The actual configuration of large-scale reconfigurable space platforms can change due to complex space missions. Therefore, designing a more versatile, high-precision control scheme to achieve takeover control of large-scale reconfigurable space platforms after on-orbit splicing and reconstruction is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] The purpose of the present invention is to provide a method and system for controlling a space platform takeover after on-orbit splicing, thereby improving the control accuracy of the space platform takeover after on-orbit splicing.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A method for taking over control of a space platform after on-orbit splicing, comprising:

[0007] Establishing an attitude takeover control state space model for an on-orbit spliced ​​space platform, wherein the on-orbit spliced ​​space platform is a combination of multiple modular platforms;

[0008] Calculating a desired control torque for stabilizing the on-orbit spliced ​​space platform based on the attitude takeover control state space model, and generating a desired control torque signal according to the desired control torque;

[0009] Distributing the desired control torque signal to each modular platform according to the communication topology relationship between the modular platforms in the space platform after on-orbit splicing and the real-time energy consumption of each modular platform;

[0010] According to the sub-control torque signals allocated to each modular platform in real time, the actuators of each modular platform are controlled to generate corresponding sub-control torques.

[0011] Optionally, the attitude takeover control state space model is expressed as:

[0012]

[0013] Among them, x(t) is the state variable of the attitude takeover control state space model, is the derivative of x(t), t is time, is the roll angle of the space platform after on-orbit splicing, θ is the pitch angle of the space platform after on-orbit splicing, ψ is the yaw angle of the space platform after on-orbit splicing, is the rolling angular velocity of the space platform after on-orbit splicing, is the pitch angular velocity of the space platform after on-orbit splicing, is the yaw angular velocity of the space platform after on-orbit splicing, w(t) is the comprehensive interference, w0(t) is the external interference, u d (t) is the actuator additive fault, B1 and B2 are the input matrices of the attitude takeover control state space model, 0 3×3 is a three-dimensional zero matrix, is the first diagonal matrix, I x0 is the component of the nominal moment of inertia of the space platform on the x-axis of the principal inertia after on-orbit splicing, I y0 is the component of the nominal moment of inertia of the space platform on the y-axis of the main inertia after on-orbit splicing, I z0 is the component of the nominal moment of inertia of the space platform on the z-axis after on-orbit splicing, is the pseudo-inverse matrix of B2, ΔA I is the first unknown inertia matrix, ΔB1 ​​and ΔB2 are both the second unknown inertia matrices, u(t) is the hybrid non-fragile H2 / H∞ controller, A is the state matrix of the attitude takeover control state space model, ΔA p (t) is the parameter uncertainty matrix of the attitude takeover control state space model, C represents the measurement matrix, C2 represents the first controlled matrix, and C ∞ represents the second controlled matrix, y(t) represents the measured output of the attitude takeover control state space model, z2 represents the first control output of the system, z ∞ Represents the second control output of the system.

[0014] Optionally, calculating an expected control torque for stabilizing the on-orbit spliced ​​space platform based on the attitude takeover control state space model, and generating an expected control torque signal according to the expected control torque specifically includes:

[0015] Based on the attitude takeover control state space model, the hybrid non-fragile H2 / H ∞ The three-stage calculation process of the controller;

[0016] The first stage of the three-stage calculation process includes:

[0017] Perform a first optimization, where the formula for the first optimization is expressed as:

[0018]

[0019] Where δ is the first variable to be optimized that is greater than zero, I is the identity matrix, I2 is the first block matrix, is the second block matrix, L ∞ is the third block matrix, is the fourth block matrix;

[0020]

[0021]

[0022] Among them, L ij 、 L 16 、L 26 and L 66 are all matrices of variables to be optimized, the value ranges of i and j are both integers between 0 and 6, Σ represents the intermediate parameter, Σ=σdiag(I,I,I,I,I,0), σ is the second variable to be optimized greater than zero, diag(I,I,I,I,I,0) is the second diagonal matrix, X, Y and Z are all positive definite symmetric matrices to be optimized, γ2 is a constant greater than zero, trace(Z) is the trace of Z, W2 represents the first intermediate matrix, Z2 is the third diagonal matrix, W ∞ represents the second intermediate matrix, Z ∞ is the fourth diagonal matrix;

[0023] Z2=diag(Γ1,Γ2);

[0024] Γ1 represents the third intermediate matrix, Γ2 represents the fifth diagonal matrix, represents the expected value of the probability of occurrence of two control gain perturbations, ξ m represents the first constant, ξ a represents the second constant, ξ represents the third constant, M a Represents the first real matrix, N a represents the second real number matrix, M represents the third real number matrix, N represents the fourth real number matrix, M m represents the fifth real matrix;

[0025]

[0026]

[0027] is the fourth intermediate matrix, is the sixth intermediate matrix,

[0028] When a feasible solution exists for the first optimization formula, Get the first initial matrix and the second initial matrix

[0029] The second stage of the three-stage calculation process includes:

[0030] Perform the second optimization, and the formula for the second optimization is expressed as:

[0031]

[0032] Among them, μ1 is the penalty factor of the first algorithm, μ2 is the penalty factor of the second algorithm, is the third variable to be optimized that is greater than zero, ε1 is the fourth variable to be optimized that is greater than zero, is the first variable matrix, E2 is the first slack variable matrix, V1 is the first variable matrix to be solved, and V2 is the second variable matrix to be solved. is the first transition matrix, is the second transition matrix, is the variable matrix to be optimized, N m is the sixth real matrix;

[0033] When the second optimization formula has a feasible solution and the obtained Approaching zero, through and Solve the first transition matrix and the second transition matrix

[0034] The third stage of the three-stage calculation process includes:

[0035] The third optimization is performed, and the formula of the third optimization is expressed as:

[0036]

[0037] Among them, ε is the fifth variable to be optimized that is greater than zero, Λ is the second variable matrix, E1 second slack variable matrix;

[0038] When the third optimization formula has a feasible solution and the value of ε is less than or equal to zero, Solve for mixed non-fragile H2 / H ∞ Controller gain matrix;

[0039] According to the mixed non-fragile H2 / H ∞ The controller gain matrix is ​​used to calculate the desired control torque for stabilizing the space platform after on-orbit splicing.

[0040] Optionally, the three-stage calculation process assumes mixed non-fragile H2 / H ∞ The controller functions are performed by the modular platform's onboard computer.

[0041] Optionally, the desired control torque signal is distributed to each modular platform according to the communication topology relationship between the modular platforms in the space platform after on-orbit splicing and the real-time energy consumption of each modular platform, specifically including:

[0042] Based on the communication topology relationship between the modular platforms in the space platform after on-orbit splicing and the real-time energy consumption of each modular platform, a distributed dynamic control torque distribution strategy is constructed;

[0043] Distributing the desired control torque signal to each modular platform according to a distributed dynamic control torque distribution strategy;

[0044] The distributed dynamic control torque allocation strategy is expressed as:

[0045]

[0046] Among them, κ i (t)∈(0,1),i=1,2,...n is the control torque distribution coefficient obtained by the ith modular platform, n is the number of modular platforms, κ i The derivative of κ j (t) is the control torque distribution coefficient obtained for the j-th modular platform, is the set of neighboring modular platforms that have communication relationships with the ith modular platform, h j is the energy balance factor of the j-th modular platform, h i is the energy balance factor of the i-th modular platform.

[0047] Optionally, the control torque corresponding to the partial control torque signal assigned to the i-th modular platform is:

[0048] u i =κ i (t)u(t),i=1,2,...n.;

[0049] Wherein, u(t) is the expected control torque corresponding to the expected control torque signal, u i The control torque corresponding to the partial control torque signal assigned to the i-th modular platform.

[0050] Optionally, the control torque executed by the actuators of each modular platform is expressed as:

[0051]

[0052] Among them, [u i1 ,u i2 ,u i3 ,...u im ] is the control torque generated by the m actuators of the i-th modular platform, D i is the installation matrix of m actuators of the ith modular platform, D i The pseudo-inverse, R i is the cosine transformation matrix from the coordinate system of the ith modular platform to the space platform after on-orbit splicing.

[0053] The present invention also discloses a space platform takeover control system after on-orbit splicing, comprising:

[0054] An attitude takeover control state space model construction module is used to establish an attitude takeover control state space model of an on-orbit spliced ​​space platform; the on-orbit spliced ​​space platform is a combination of multiple modular platforms;

[0055] an expected control torque signal generating module, configured to calculate an expected control torque for stabilizing the on-orbit spliced ​​space platform based on the attitude takeover control state space model, and generate an expected control torque signal according to the expected control torque;

[0056] an expected control torque signal distribution module, configured to distribute the expected control torque signal to each modular platform according to the communication topology relationship between the modular platforms in the space platform after on-orbit splicing and the real-time energy consumption of each modular platform;

[0057] The sub-control torque signal execution module is used to control the actuators of each modular platform to generate corresponding sub-control torques according to the sub-control torque signals allocated to each modular platform in real time.

[0058] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0059] The present invention is based on a universal attitude takeover control state space model, calculates the expected control torque of a stable on-orbit spliced ​​space platform, generates an expected control torque signal based on the expected control torque, and distributes the expected control torque signal to each modular platform based on the communication topology relationship between the modular platforms in the on-orbit spliced ​​space platform and the real-time energy consumption of each modular platform. This can balance the energy consumption between the modular platforms and improve the control accuracy through real-time energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0061] Figure 1 A schematic flow chart of a method for controlling a space platform after on-orbit splicing provided by an embodiment of the present invention;

[0062] Figure 2 A schematic diagram of a takeover control scenario for a space platform supporting on-orbit splicing provided by an embodiment of the present invention;

[0063] Figure 3 A schematic diagram of a curve showing a change in the desired control torque signal obtained by a three-stage method for a modular platform that performs controller functions according to an embodiment of the present invention;

[0064] Figure 4 A schematic diagram of a curve showing the change in the vector sum of the actual control torques generated by the modular platforms according to the distributed dynamic control torque allocation strategy provided in an embodiment of the present invention;

[0065] Figure 5 A schematic diagram of a curve showing the change in the difference between the desired control torque signal obtained by the three-stage method provided in an embodiment of the present invention and the vector sum of the actual control torques generated by each modular platform;

[0066] Figure 6 A schematic diagram of a curve showing changes in attitude angle of a large-scale reconfigurable space platform provided by an embodiment of the present invention under the action of actual control torques jointly generated by various modular platforms;

[0067] Figure 7 A schematic diagram of a curve showing changes in the attitude angular velocity of a large-scale reconfigurable space platform provided by an embodiment of the present invention under the action of the actual control torque jointly generated by each modular platform. DETAILED DESCRIPTION

[0068] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0069] The purpose of the present invention is to provide a method and system for controlling a space platform takeover after on-orbit splicing, thereby improving the control accuracy of the space platform takeover after on-orbit splicing.

[0070] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0071] like Figure 1 As shown, this embodiment provides a method for taking over control of a space platform after on-orbit splicing, which includes the following steps.

[0072] Step 101: Establishing an attitude takeover control state space model of an on-orbit spliced ​​space platform; the on-orbit spliced ​​space platform is a combination of multiple modular platforms.

[0073] Step 102: Based on the attitude takeover control state space model, calculate the expected control torque for stabilizing the on-orbit spliced ​​space platform, and generate an expected control torque signal according to the expected control torque.

[0074] Step 103: Distribute the desired control torque signal to each modular platform according to the communication topology relationship between the modular platforms in the space platform after on-orbit splicing and the real-time energy consumption of each modular platform.

[0075] Step 104: According to the partial control torque signal allocated to each modular platform in real time, the actuator of each modular platform is controlled to generate a corresponding partial control torque.

[0076] The on-orbit spliced ​​space platform specifically refers to a large-scale reconfigurable space platform after on-orbit splicing.

[0077] After the large reconfigurable space platform completes on-orbit splicing and reconstruction, the rotational inertia information under the current configuration is determined through preliminary parameter identification, and the installation matrix of each modular platform and the conversion matrix between the coordinate system of each modular platform body and the coordinate system of the large reconfigurable space platform body are clarified. The takeover control scenario of the space platform after on-orbit splicing is as follows: Figure 2 shown.

[0078] Among them, step 101 specifically includes: in view of the accuracy limitation of the early parameter identification of the large-scale reconfigurable space platform after on-orbit splicing, in the presence of external interference, actuator additive failure and large-scale reconfigurable space platform model parameter uncertainty, establishing an inertia-independent dynamic model of the space platform after on-orbit splicing, and converting the inertia-independent dynamic model into a general attitude takeover control state space model.

[0079] The attitude takeover control state space model is expressed as:

[0080]

[0081] Among them, x(t) is the state variable of the attitude takeover control state space model (state space model), is the derivative of x(t), t is time, is the roll angle of the space platform (large reconfigurable space platform) after on-orbit splicing, θ is the pitch angle of the space platform after on-orbit splicing, ψ is the yaw angle of the space platform after on-orbit splicing, is the rolling angular velocity of the space platform after on-orbit splicing, is the pitch angular velocity of the space platform after on-orbit splicing, is the yaw angular velocity of the space platform after on-orbit splicing, w(t) is the comprehensive interference, w0(t) is the external interference, u d (t) is the actuator additive fault, B1 and B2 are the input matrices of the attitude takeover control state space model, 0 3×3 is a three-dimensional zero matrix, is the first diagonal matrix, I x0 is the component of the nominal moment of inertia of the space platform on the x-axis of the principal inertia after on-orbit splicing, I y0 is the component of the nominal moment of inertia of the space platform on the y-axis of the main inertia after on-orbit splicing, I z0 is the component of the nominal moment of inertia of the space platform on the z-axis after on-orbit splicing, is the pseudo-inverse matrix of B2, ΔA I is the first unknown inertia matrix, ΔB1 ​​and ΔB2 are both the second unknown inertia matrices, u(t) is the hybrid non-fragile H2 / H∞ controller, A is the state matrix of the attitude takeover control state space model, ΔA p (t) is the parameter uncertainty matrix of the attitude takeover control state space model, C represents the measurement matrix, C2 represents the first controlled matrix, and C ∞ represents the second controlled matrix, y(t) represents the measured output of the attitude takeover control state space model, z2 represents the first control output of the system (referring to the large reconfigurable space platform), z ∞Represents the second control output of the system.

[0082]

[0083] Among them, I x is the component of the nominal moment of inertia of the large reconfigurable space platform on the main inertia axis x-axis, I y is the component of the real moment of inertia of the large reconfigurable space platform on the main inertia axis y, I z is the component of the real moment of inertia of the large reconfigurable space platform on the main inertia axis z, is the sixth diagonal matrix, and generate.

[0084] is the state matrix of the state space model, ω e is the orbital angular velocity of the large reconfigurable space platform, ΔA p (t) = MF(t)N is the parameter uncertainty matrix of the state space model, M and N are real number matrices with known values, F(t) is a Lebesgue measurable matrix function, and its norm satisfies ||F(t)||≤1 for any time t, u(t) is a mixed non-fragile H2 / H ∞ controller, which satisfies K is a mixed non-fragile H2 / H ∞ Controller gain matrix, ΔK a =M a F a (t)N a is the controller gain additive perturbation, M a and N a A known real matrix, F a (t) is a Lebesgue measurable matrix function whose norm satisfies ||F for any time t. a (t)||≤1,ΔK m =M m F m (t)N m K is the controller gain multiplication perturbation, M m and N m A known real matrix, F m (t) is a Lebesgue measurable matrix function whose norm satisfies ||F for any time t. m (t)||≤1, is the expected value of the probability of occurrence of the two control gain perturbations.

[0085] Among them, step 102 is based on the general attitude takeover control state space model of large reconfigurable space platform, and under the condition that the two controller gain perturbations exist at the same time, a hybrid non-fragile H2 / H is preset for the modular platform that assumes the controller function. ∞ The modular platform that assumes the controller function calculates the control torque required to stabilize the large-scale reconfigurable space platform based on the three-stage calculation scheme and generates the corresponding control torque signal. Specifically, it includes:

[0086] Based on the attitude takeover control state space model, the hybrid non-fragile H2 / H ∞ The three-stage calculation process of the controller.

[0087] The first stage of the three-stage calculation process includes:

[0088] Perform a first optimization, where the formula for the first optimization is expressed as:

[0089]

[0090] Where δ is the first variable to be optimized that is greater than zero, I is the identity matrix, I2 is the first block matrix, is the second block matrix, L ∞ is the third block matrix, is the fourth block matrix.

[0091]

[0092]

[0093] Among them, L ij 、 L 16 , L 26 and L 66 are all variable matrices to be optimized, and the value ranges of i and j are integers between 0 and 6, that is, L ij (i,j=1,2,3,4,5), Σ represents the intermediate parameter, Σ=σdiag(I,I,I,I,I,0), σ is the second variable to be optimized greater than zero, diag(I,I,I,I,I,0) is the second diagonal matrix, X, Y and Z are all positive definite symmetric matrices to be optimized, γ2 is a constant greater than zero, trace(Z) is the trace of Z, W2 represents the first intermediate matrix, Z2 is the third diagonal matrix, W ∞ Represents the second intermediate matrix, Z ∞ is the fourth diagonal matrix;

[0094] Z2=diag(Γ1,Γ2);

[0095] Γ1 represents the third intermediate matrix, Γ2 represents the fifth diagonal matrix, represents the expected value of the probability of occurrence of two control gain perturbations, ξ m represents the first constant, ξ a represents the second constant, ξ represents the third constant, M a Represents the first real matrix, N a represents the second real number matrix, M represents the third real number matrix, N represents the fourth real number matrix, M m represents the fifth real matrix;

[0096]

[0097]

[0098] is the fourth intermediate matrix, is the sixth intermediate matrix,

[0099] When a feasible solution exists for the first optimization formula, and Get the first initial matrix and the second initial matrix

[0100] The first initial matrix and the second initial matrix It is the initial matrix for starting the second stage of the algorithm.

[0101] The second stage of the three-stage calculation process includes:

[0102] Perform the second optimization, and the formula for the second optimization is expressed as:

[0103]

[0104] Among them, μ1 is the penalty factor of the first algorithm, μ2 is the penalty factor of the second algorithm, is the third variable to be optimized that is greater than zero, ε1 is the fourth variable to be optimized that is greater than zero, is the first variable matrix, E2 is the first slack variable matrix, V1 is the first variable matrix to be solved, and V2 is the second variable matrix to be solved. is the first transition matrix, is the second transition matrix, is the variable matrix to be optimized, N m is the sixth real matrix.

[0105] When the second optimization formula has a feasible solution and the obtained When it approaches zero (less than the set value), and Solve the first transition matrix and the second transition matrix get and The exact value of and The exact value of is used to start the third stage algorithm.

[0106] The third stage of the three-stage calculation process includes:

[0107] The third optimization is performed, and the formula of the third optimization is expressed as:

[0108]

[0109] Among them, ε is the fifth variable to be optimized that is greater than zero, Λ is the second variable matrix, E1 is the second slack variable matrix.

[0110] When the third optimization formula has a feasible solution and the value of ε is less than or equal to zero, Solve for mixed non-fragile H2 / H ∞ Controller gain matrix K.

[0111] If the third optimal formula has a feasible solution and the value of ε is greater than zero, then first pass Solve for mixed non-fragile H2 / H ∞ The controller gain matrix K, let and will be re and Re-substitute the third optimization formula and solve it until the third optimization formula has a feasible solution and the value of ε obtained is less than or equal to zero, and then further Solve for mixed non-fragile H2 / H ∞ Controller gain matrix K.

[0112] According to the mixed non-fragile H2 / H ∞ The controller gain matrix calculates the desired control torque for stabilizing the on-orbit spliced ​​space platform through u(t)=Ky(t) and generates a corresponding control torque signal.

[0113] The three-step calculation process assumes mixed non-fragile H2 / H ∞ The controller functions are performed by the modular platform's onboard computer.

[0114] Wherein, step 103 specifically includes:

[0115] Define the energy balance factor matrix H = diag(h1,h2,h3,...hn ), where h1,h2,h3,...h n Respectively reflect the energy balance factors of the first modular platform to the nth modular platform, h1, h2, h3, ... h n The value of is proportional to the energy consumption from the 1st modular platform to the nth modular platform.

[0116] Define the control torque distribution matrix κ=[κ1(t),κ2(t),...κ n (t)] T , where κ i (t)∈(0,1),i=1,2,...n is the control torque distribution coefficient obtained by the ith modular platform, that is, the control torque allocated to the ith modular platform is u i =κ i (t)u(t),i=1,2,...n., and satisfies u(t) is the control torque signal corresponding to the control torque required to stabilize the large reconfigurable space platform generated by the modular platform that assumes the controller function.

[0117] According to the communication topology relationship between the modular platforms in the space platform after on-orbit splicing and the real-time energy consumption of each modular platform, a distributed dynamic control torque distribution strategy is constructed.

[0118] Undertake controller (hybrid non-fragile H2 / H ∞ The modular platform with the controller function distributes the control torque signal to each modular platform according to the distributed dynamic control torque distribution strategy.

[0119] The distributed dynamic control torque allocation strategy is expressed as:

[0120]

[0121] Among them, κ i (t)∈(0,1),i=1,2,...n is the control torque distribution coefficient obtained by the ith modular platform, n is the number of modular platforms, κ i The derivative of κ j (t) is the control torque distribution coefficient obtained for the j-th modular platform, is the set of neighboring modular platforms that have communication relationships with the ith modular platform, h j is the energy balance factor of the j-th modular platform, h i is the energy balance factor of the i-th modular platform.

[0122] The control torque corresponding to the control torque signal assigned to the i-th modular platform is:

[0123] u i =κ i (t)u(t),i=1,2,...n.;

[0124] Wherein, u(t) is the expected control torque corresponding to the expected control torque signal, u i The control torque corresponding to the partial control torque signal assigned to the i-th modular platform.

[0125] Real-time feedback on the energy consumption of all modular platforms is provided, the energy balance factor is updated, and the distributed dynamic control torque distribution strategy is substituted to dynamically adjust the distribution coefficient.

[0126] Among them, in step 104, the actuators of each modular platform generate corresponding control torques according to the allocated control torque signals, and all control torques work together to achieve attitude stabilization of the large reconfigurable space platform, thereby achieving its takeover control.

[0127] After each modular platform receives the assigned control torque signal, the onboard computer of each modular platform calculates the control torque required by each actuator according to the following conversion relationship. The control torque executed by the actuator of each modular platform is expressed as:

[0128]

[0129] Among them, [u i1 ,u i2 ,u i3 ,...u im ] is the control torque generated by the m actuators of the i-th modular platform, D i is the installation matrix of m actuators of the ith modular platform, D i The pseudo-inverse, R i is the cosine transformation matrix from the coordinate system of the ith modular platform to the space platform after on-orbit splicing.

[0130] Each actuator of each modular platform generates a control torque calculated according to the above relationship, and all control torques work together to achieve attitude stabilization of the large reconfigurable space platform.

[0131] The following numerical simulation is used to verify the control method of a space platform after on-orbit splicing in this embodiment.

[0132] After the large reconfigurable space platform completes on-orbit splicing and reconstruction, it is composed of 8 modular platforms spliced ​​on-orbit, that is, n = 8. After preliminary parameter identification, the nominal rotational inertia parameters of the current configuration are determined: I x0 =5100kg·m 2 , I y0 =5090kg·m 2 , I z0 =5075kg·m 2 .

[0133] Considering the accuracy of parameter identification, the actual moment of inertia parameters are selected as:

[0134] I x =5100×(1.05+0.01sin(0.11πt))kg·m 2 , I y =5090×(1.05+0.01sin(0.11πt))kg·m 2 ,

[0135] I z =5075×(1.05+0.01sin(0.11πt))kg·m 2 .

[0136] Each modular platform is equipped with 3 actuators, that is, m=3, and the assembly matrix is ​​D i =I 3×3 ,i=1,2,3,...8.

[0137] The large reconfigurable space platform is located in a circular orbit at an altitude of 300 km and an orbital angular velocity of ω e =0.0011586rad / s, the maximum sum of the control torques provided by the 8 modular platforms does not exceed 60Nm, where Nm stands for Newton meter.

[0138] The installation matrix of each modular platform and the conversion matrix between the coordinate system of each modular platform body and the coordinate system of the large reconfigurable space platform body are:

[0139]

[0140]

[0141]

[0142]

[0143] External interference is:

[0144] The Lebesgue measurable matrix function and its corresponding constant matrix are:

[0145] F(t)=sin(0.11πt), M=0.01×1 6×1 , N = 1 1×6

[0146] F a (t)=sin(0.11πt+π / 4), M a =0.02×1 3×1 , N a =1 1×6 .

[0147] F m (t) = cos(0.11πt), M m =1 3×1 , N m =0.01×1 1×3

[0148] Correlation constant: γ2=0.1,γ ∞ =0.1, ξ=1,ξ a =1,ξ m =1,μ1=1,μ2=2,α=10 -5 .

[0149] The initial values ​​of the state variables of the state space model are:

[0150]

[0151] The actuator summing fault is

[0152] The first modular platform is used to assume the controller function. The controller gain matrix obtained by executing the three-stage method is:

[0153] The Laplace matrix representing the communication topology relationship between the eight modular platforms is:

[0154]

[0155] The initial value of the partition coefficient is:

[0156] The energy balance factors h1, h2, h3, ... h8 are inversely proportional to the energy surplus of the corresponding modular platform.

[0157] The measurement matrix and the two controlled matrices are: C = 10 × I 6×6 , C2=I 6×6 , C ∞ =I 6×6 .

[0158] The modular platform that assumes the controller function can stabilize the control torque signal of the large reconfigurable space platform by calculating u(t)=Ky(t). The control torque signal is distributed to each modular platform according to the distributed dynamic control torque distribution strategy. Each platform generates a corresponding control torque to jointly control the large reconfigurable space platform. Figures 3 to 7 is the corresponding simulation curve, Figure 3 It is the expected control torque signal calculated by the modular platform 1 that can stabilize the large reconfigurable space platform. The control torque signal is always limited within 60Nm. Figure 4 It is the sum of the actual control torque vectors generated by each platform after being distributed to each modular platform through the distributed dynamic control torque distribution law. Figure 5 is the difference between the desired control torque signal and the sum of the actual control torque vector. The difference between the two shows that the distribution accuracy is 4×10 -13 Nm, it can be seen that the distributed dynamic control torque distribution law is effective. Figure 6 This is the attitude angle change curve of a large reconfigurable space platform under the actual control torque generated by each platform. The attitude angle reaches stability within 60 seconds, and the stability accuracy is less than 0.001rad after 70 seconds. Figure 7 This is the attitude angular velocity change curve of the large reconfigurable space platform under the actual control torque generated by each platform. The attitude angular velocity reaches stability within 60 seconds, and the stability accuracy is less than 0.001rad / s after 70 seconds.

[0159] Figure 3 in, u x 、u y and u z are the components of the expected control torque signal on the three axes of the large reconfigurable space platform system coordinate axis, and the unit of the expected control torque signal is Newton meter. Figure 4 in, u rx 、u ry and u rz They are respectively the vector of the actual control torque and its components on the three axes of the coordinate axis of the large reconfigurable space platform system. Figure 5 In the example, the change curve is used to characterize the distribution error of the distributed dynamic control torque distribution strategy, e x 、e y and e z are the components of the difference on the three axes of the large reconfigurable space platform system coordinate axis. Figure 6 middle, is the roll angle of the large reconfigurable space platform, θ is the pitch angle of the large reconfigurable space platform, ψ is the yaw angle of the large reconfigurable space platform, and rad indicates that the unit of the angle is radians. Figure 7 In, ω xis the roll angular velocity of the large reconfigurable space platform, ω y is the pitch angular velocity of the large reconfigurable space platform, ω z is the yaw angular velocity of the large reconfigurable space platform, and rad / s represents the angular velocity in radians per second.

[0160] It can be seen that the large-scale reconfigurable space platform takeover control method supporting on-orbit splicing of the present invention can be used to design an effective hybrid non-fragile H2 / H for modular platforms that assume controller functions. ∞ The controller can enable each modular platform to accurately reproduce the implementation of hybrid non-fragile H2 / H under the designed distributed dynamic control torque distribution strategy. ∞ The controller then stabilizes the large reconfigurable space platform and takes over it.

[0161] The beneficial effects of the present invention are as follows.

[0162] 1) An inertia-independent dynamic model of a large-scale reconfigurable space platform after on-orbit splicing is established and converted into a general attitude takeover control state-space model. After the basic parameter information is obtained through parameter identification of the large-scale space platform after on-orbit splicing and reconstruction, control calculations can be carried out.

[0163] 2) A three-stage calculation scheme for calculating the hybrid non-fragile H2 / H∞ controller that can stabilize the space platform is preset for the modular platform that assumes the controller function in the large-scale reconfigurable space platform.

[0164] 3) The designed distributed dynamic control allocation law can ensure that all modular platforms can reproduce the desired control torque in real time and with high precision, and can dynamically adjust the allocation coefficient according to the energy consumption of each platform to ensure the balance of energy consumption of each modular platform.

[0165] Example 2

[0166] This embodiment provides a space platform takeover control system after on-orbit splicing, including:

[0167] The attitude takeover control state space model construction module is used to establish the attitude takeover control state space model of the on-orbit spliced ​​space platform; the on-orbit spliced ​​space platform is a combination of multiple modular platforms.

[0168] The expected control torque signal generating module is used to calculate the expected control torque for stabilizing the on-orbit spliced ​​space platform based on the attitude takeover control state space model, and generate an expected control torque signal according to the expected control torque.

[0169] The expected control torque signal distribution module is used to distribute the expected control torque signal to each modular platform according to the communication topology relationship between the modular platforms in the space platform after on-orbit splicing and the real-time energy consumption of each modular platform.

[0170] The sub-control torque signal execution module is used to control the actuators of each modular platform to generate corresponding sub-control torques according to the sub-control torque signals allocated to each modular platform in real time.

[0171] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0172] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A method for taking over control of a space platform after on-orbit splicing, characterized in that: include: Establishing an attitude takeover control state space model for an on-orbit spliced ​​space platform, wherein the on-orbit spliced ​​space platform is a combination of multiple modular platforms; Calculating a desired control torque capable of stabilizing the on-orbit spliced ​​space platform based on the attitude takeover control state space model, and generating a desired control torque signal according to the desired control torque; Distributing the desired control torque signal to each modular platform according to the communication topology relationship between the modular platforms in the space platform after on-orbit splicing and the real-time energy consumption of each modular platform; According to the sub-control torque signals allocated to each modular platform in real time, the actuators of each modular platform are controlled to generate corresponding sub-control torques.

2. The method for taking over control of a space platform after on-orbit splicing according to claim 1, characterized in that: The attitude takeover control state space model is expressed as: Among them, x(t) is the state variable of the attitude takeover control state space model, is the derivative of x(t), t is time, is the roll angle of the space platform after on-orbit splicing, θ is the pitch angle of the space platform after on-orbit splicing, ψ is the yaw angle of the space platform after on-orbit splicing, is the rolling angular velocity of the space platform after on-orbit splicing, is the pitch angular velocity of the space platform after on-orbit splicing, is the yaw angular velocity of the space platform after on-orbit splicing, w(t) is the comprehensive interference, w0(t) is the external interference, u d (t) is the actuator additive fault, B1 and B2 are the input matrices of the attitude takeover control state space model, 0 3×3 is a three-dimensional zero matrix, is the first diagonal matrix, I x0 is the component of the nominal moment of inertia of the space platform on the x-axis of the principal inertia after on-orbit splicing, I y0 is the component of the nominal moment of inertia of the space platform on the y-axis of the main inertia after on-orbit splicing, I z0 is the component of the nominal moment of inertia of the space platform on the z-axis after on-orbit splicing, is the pseudo-inverse matrix of B2, ΔA I is the first unknown inertia matrix, ΔB1 ​​and ΔB2 are both the second unknown inertia matrices, u(t) is the hybrid non-fragile H2 / H∞ controller, A is the state matrix of the attitude takeover control state space model, ΔA p (t) is the parameter uncertainty matrix of the attitude takeover control state space model, C represents the measurement matrix, C2 represents the first controlled matrix, and C ∞ represents the second controlled matrix, y(t) represents the measured output of the attitude takeover control state space model, z2 represents the first control output of the system, z ∞ Represents the second control output of the system.

3. The method for controlling a space platform after on-orbit splicing according to claim 2, characterized in that: Calculating the desired control torque for stabilizing the on-orbit spliced ​​space platform based on the attitude takeover control state space model, and generating the desired control torque signal according to the desired control torque, specifically including: Based on the attitude takeover control state space model, the hybrid non-fragile H2 / H ∞ The three-stage calculation process of the controller; The first stage of the three-stage calculation process includes: Perform a first optimization, where the formula for the first optimization is expressed as: Where δ is the first variable to be optimized that is greater than zero, I is the identity matrix, I2 is the first block matrix, is the second block matrix, L ∞ is the third block matrix, is the fourth block matrix; Among them, L ij 、 L 16 、L 26 and L 66 are all matrices of variables to be optimized, the value ranges of i and j are both integers between 0 and 6, Σ represents the intermediate parameter, Σ=σdiag(I,I,I,I,I,0), σ is the second variable to be optimized greater than zero, diag(I,I,I,I,I,0) is the second diagonal matrix, X, Y and Z are all positive definite symmetric matrices to be optimized, γ2 is a constant greater than zero, trace(Z) is the trace of Z, W2 represents the first intermediate matrix, Z2 is the third diagonal matrix, W ∞ represents the second intermediate matrix, Z ∞ is the fourth diagonal matrix; Z2=diag(Γ1,Γ2); Γ1 represents the third intermediate matrix, Γ2 represents the fifth diagonal matrix, represents the expected value of the probability of occurrence of two control gain perturbations, ξ m represents the first constant, ξ a represents the second constant, ξ represents the third constant, M a Represents the first real matrix, N a represents the second real number matrix, M represents the third real number matrix, N represents the fourth real number matrix, M m represents the fifth real matrix; is the fourth intermediate matrix, is the sixth intermediate matrix, When a feasible solution exists for the first optimization formula, and Get the first initial matrix and the second initial matrix The second stage of the three-stage calculation process includes: Perform the second optimization, and the formula for the second optimization is expressed as: Among them, μ1 is the penalty factor of the first algorithm, μ2 is the penalty factor of the second algorithm, is the third variable to be optimized that is greater than zero, ε1 is the fourth variable to be optimized that is greater than zero, is the first variable matrix, E2 is the first slack variable matrix, V1 is the first variable matrix to be solved, and V2 is the second variable matrix to be solved. is the first transition matrix, is the second transition matrix, is the variable matrix to be optimized, N m is the sixth real matrix; When the second optimization formula has a feasible solution and the obtained Approaching zero, through and Solve the first transition matrix and the second transition matrix The third stage of the three-stage calculation process includes: The third optimization is performed, and the formula of the third optimization is expressed as: Among them, ε is the fifth variable to be optimized that is greater than zero, Λ is the second variable matrix, E1 second slack variable matrix; When the third optimization formula has a feasible solution and the value of ε is less than or equal to zero, Solve for mixed non-fragile H2 / H ∞ Controller gain matrix; According to the mixed non-fragile H2 / H ∞ The controller gain matrix is ​​used to calculate the desired control torque for stabilizing the space platform after on-orbit splicing.

4. The method for controlling a space platform after on-orbit splicing according to claim 3 is characterized in that: The three-step calculation process assumes mixed non-fragile H2 / H ∞ The controller functions are performed by the modular platform's onboard computer.

5. The method for controlling a space platform after on-orbit splicing according to claim 1, characterized in that: The desired control torque signal is distributed to each modular platform according to the communication topology relationship between the modular platforms in the space platform after on-orbit splicing and the real-time energy consumption of each modular platform, specifically including: Based on the communication topology relationship between the modular platforms in the space platform after on-orbit splicing and the real-time energy consumption of each modular platform, a distributed dynamic control torque distribution strategy is constructed; Distributing the desired control torque signal to each modular platform according to a distributed dynamic control torque distribution strategy; The distributed dynamic control torque allocation strategy is expressed as: Among them, κ i (t)∈(0,1),i=1,2,...n is the control torque distribution coefficient obtained by the ith modular platform, n is the number of modular platforms, κ i The derivative of κ j (t) is the control torque distribution coefficient obtained for the j-th modular platform, is the set of neighboring modular platforms that have communication relationships with the ith modular platform, h j is the energy balance factor of the j-th modular platform, h i is the energy balance factor of the i-th modular platform.

6. The method for controlling a space platform after on-orbit splicing according to claim 5, characterized in that: The control torque corresponding to the control torque signal assigned to the i-th modular platform is: u i =κ i (t)u(t),i=1,2,...n.; Wherein, u(t) is the expected control torque corresponding to the expected control torque signal, u i The control torque corresponding to the partial control torque signal assigned to the i-th modular platform.

7. The method for controlling a space platform after on-orbit splicing according to claim 6, characterized in that: The control torque executed by the actuators of each modular platform is expressed as: Among them, [u i1 ,u i2 ,u i3 ,...u im ] is the control torque generated by the m actuators of the i-th modular platform, D i is the installation matrix of m actuators of the ith modular platform, D i The pseudo-inverse, R i is the cosine transformation matrix from the coordinate system of the ith modular platform to the space platform after on-orbit splicing.

8. A space platform takeover control system after on-orbit splicing, characterized in that: include: An attitude takeover control state space model construction module is used to establish an attitude takeover control state space model of an on-orbit spliced ​​space platform; the on-orbit spliced ​​space platform is a combination of multiple modular platforms; an expected control torque signal generating module, configured to calculate an expected control torque capable of stabilizing the space platform after on-orbit splicing based on the attitude takeover control state space model, and generate an expected control torque signal according to the expected control torque; an expected control torque signal distribution module, configured to distribute the expected control torque signal to each modular platform according to the communication topology relationship between the modular platforms in the space platform after on-orbit splicing and the real-time energy consumption of each modular platform; The sub-control torque signal execution module is used to control the actuators of each modular platform to generate corresponding sub-control torques according to the sub-control torque signals allocated to each modular platform in real time.

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