Game control method for agile spacecraft maneuvering and low-stiffness vibration isolation of super-static load

Abstract

The present invention discloses a game control method for agile spacecraft maneuvers and low-rigidity vibration isolation of hyperstatic loads, which relates to the field of micro-vibration control of spacecraft and aircraft, including: proposing a hypothesis on the relationship between agile spacecraft, vibration isolation device and hyperstatic load; establishing a dynamic model of agile spacecraft maneuvering and a dynamic model of vibration isolation device based on the hypothesis; establishing a dynamic model of maneuvering-vibration isolation game system based on the dynamic model of agile spacecraft maneuvering and the dynamic model of vibration isolation device; constructing a performance index function of the game system and Hamiltonian equation to obtain the Riccati differential equation corresponding to the maneuvering-vibration isolation game system; solving the Riccati differential equation to obtain the optimal output of the maneuvering-vibration isolation game system. The present invention solves the problem that the existing control method is difficult to achieve balanced control of hyperstatic load with agile maneuvering of the spacecraft body and micro-vibration isolation, and is very likely to cause collision of actuators inside the vibration isolation device, affecting the application of hyperstatic load on agile spacecraft.

Description

Technical Field

[0001] The present invention relates to the field of micro-vibration control of spacecraft and aircraft, and in particular to a game control method for agile spacecraft maneuvering and ultra-static load low-rigidity vibration isolation. Background Art

[0002] At present, active isolation and suppression of micro-vibration of spacecraft platforms through vibration isolation devices is a common method used for ultra-quiet operation of precision payloads in space. However, ordinary satellites have less demand for agile maneuvers on orbit, and the attitude and orbit control bandwidth is limited. The control mode used is mainly to perform ultra-quiet control of the payload under stable platform conditions, and there is little research on micro-vibration control during maneuvers.

[0003] The ultra-static load vibration isolator with zero stiffness / low stiffness design has received extensive attention in the new generation of space high-precision applications and is an important way to achieve broadband micro-vibration suppression. However, unlike ordinary satellite platforms, for spacecraft with agile maneuvering requirements, the load needs to be connected to the platform with high stiffness to achieve rapid follow-up during the maneuvering process, which conflicts with the low stiffness connection requirement for broadband micro-vibration suppression. It is difficult for the ultra-static load based on the ideal separation design to achieve agile maneuvers and micro-vibration isolation balanced control at the same time under the agile maneuvering operation of the spacecraft, and it is difficult to ensure high-precision and stable pointing control of the load in a high-dynamic application environment. In addition, under agile maneuvering operations, due to the limitation of the actuation gap, the separated actuator is prone to collision. The document "Ultra-static and Ultra-stable Satellite Impact Vibration Dynamics Modeling" points out the problem of actuator collision caused by agile maneuvers. The agile maneuvers of spacecraft will not only seriously affect the accuracy and stability of the ultra-static load, but also restore the ultra-static and ultra-stable vibration isolation state for more than 1400 seconds, making it difficult to achieve balanced control of ultra-static load maneuvers and vibration isolation. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the game control method of agile spacecraft maneuvers and low-rigidity vibration isolation of hyperstatic loads provided by the present invention solves the problem that the existing control methods are difficult to achieve balanced control of hyperstatic loads with the agile maneuvers of the spacecraft body and micro-vibration isolation, and are very likely to cause collisions with the actuators inside the vibration isolation device, affecting the application of hyperstatic loads on agile spacecraft.

[0005] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is: a game control method for agile spacecraft maneuvering and low-stiffness vibration isolation of super-static load, comprising the following steps:

[0006] S1: Hypothesis on the relationship between agile spacecraft, vibration isolation devices and hyperstatic loads;

[0007] S2: Establish the maneuvering dynamics model of agile spacecraft and the dynamics model of vibration isolation device based on the assumptions;

[0008] S3: Based on the agile spacecraft maneuvering dynamics model and the vibration isolation device dynamics model, a maneuvering-vibration isolation system dynamics model is established;

[0009] S4: Based on the dynamics model of the maneuvering-vibration isolation game system, the performance index function and Hamiltonian equation of the game system are constructed to obtain the Riccati differential equation corresponding to the maneuvering-vibration isolation game system;

[0010] S5: Solve the Riccati differential equation to obtain the optimal output of the maneuver-vibration isolation game system, and complete the game control of agile spacecraft maneuvers and low-stiffness vibration isolation of super-static loads.

[0011] The beneficial effect of the above scheme is: the present invention proposes a game control method for agile spacecraft maneuvers and low-rigidity vibration isolation of excess static loads. When the spacecraft is agilely maneuvering, it is modeled as a game problem between the excess static load following maneuverability and the vibration isolation capability. By controlling the relative state and the aircraft following movement, collision with the spacecraft platform and the vibration isolation device is avoided. At the same time, the micro-vibration outside the maneuvering signal of the spacecraft platform can be isolated as much as possible, which solves the problem that the existing control method is difficult to achieve balanced control of the excess static load following the agile maneuvering of the spacecraft body and the isolation of micro-vibrations, and is very likely to cause collision of the actuator inside the vibration isolation device, affecting the application of the excess static load on agile spacecraft.

[0012] Furthermore, it is assumed in S1 that: the excess static load is mounted on the upper platform of the vibration isolation device, the lower platform of the vibration isolation device is fixedly connected to the agile spacecraft, a low-rigidity connection is adopted between the upper platform of the vibration isolation device and the lower platform of the vibration isolation device, the follow-up maneuver and vibration isolation of the excess static load are achieved through the vibration isolation device, and the vibration isolation device can output continuous operating force.

[0013] The beneficial effect of the above further scheme is that the above assumptions need to be made in order to obtain an accurate dynamic model for this scenario and solve the maneuver-vibration isolation control rate expression.

[0014] Furthermore, the agile spacecraft maneuvering dynamics model in S2 for:

[0015]

[0016]

[0017]

[0018]

[0019]

[0020]

[0021] in, For the Agile Spacecraft System Matrix, is the selected agile spacecraft state vector, Input matrix for agile spacecraft, 12-dimensional input vector for the agile spacecraft, is a 6×6 identity matrix, is the agile spacecraft state variable, are the mass and inertia matrices of the agile spacecraft, is the maneuvering control force or torque acting on the agile spacecraft, , , , , and are the generalized coordinates of the agile spacecraft in the inertial system, is the transpose of the matrix;

[0022] The fitted Jacobian matrix of the agile spacecraft maneuvering dynamics model for:

[0023]

[0024] in, Inertial coordinate system Lower vibration isolation device actuator The unit direction vector of The lower hinge point of the actuator is in the aircraft system The position vector of .

[0025] Furthermore, the dynamic model of the vibration isolation device in S2 for:

[0026]

[0027]

[0028]

[0029]

[0030]

[0031] is the vibration isolation device system matrix, is the state vector of the selected vibration isolation device, Enter the matrix for the vibration isolation device, Active control of load following maneuvers by the vibration isolation device, The vibration isolation device is used to isolate the control force of micro vibration outside the maneuvering signal during the maneuvering process. 12× r The matrix of order, r is the number of actuators in the vibration isolation device, is the first transformation matrix, is the second transformation matrix, is the third transformation matrix, is the mass and inertia matrix of the vibration isolation device, is the installation Jacobian matrix of the vibration isolation device, is the damping matrix connecting the upper and lower platforms of the vibration isolation device, is the equivalent stiffness matrix of the connection between the upper and lower platforms of the vibration isolation device, , , , , and are the generalized coordinates in the inertial system of the superstatic load, , and are the corresponding angular velocities respectively;

[0032] The installed Jacobian matrix of the vibration isolation device dynamic model is for:

[0033]

[0034] in, The hinge point of the actuator is in the vibration isolation device. The position vector of .

[0035] Furthermore, the dynamics model of the maneuver-vibration isolation game system in S3 for:

[0036]

[0037] in, is the system matrix of the game system, is the state variable, is the input matrix of the vibration isolation device in the game system, is the input matrix of the agile spacecraft in the game system.

[0038] The beneficial effect of the above further scheme is that by combining the above agile spacecraft dynamics model and the vibration isolator dynamics model, the dynamics equation of the maneuvering-vibration isolation game system can be obtained.

[0039] Furthermore, the performance index functions of the gaming system in S4 include:

[0040] Following maneuverability performance index of super static load for:

[0041]

[0042] in, is the state variable function, To control the initial time, To control the terminal moment, , and is the adjustable weighting matrix of the super static load following maneuver index, For time;

[0043] Vibration isolation performance index for super static load for:

[0044]

[0045] in, , and It is an adjustable weighting matrix for the super static load vibration isolation performance index.

[0046] Furthermore, the Hamiltonian equation in S4 is:

[0047]

[0048] in, is the first equation, is the second equation, for The corresponding covariate, for The corresponding covariate.

[0049] Furthermore, the Riccati differential equation corresponding to the maneuver-vibration isolation game system in S4 is:

[0050]

[0051] in, is the assumed covariate The time-varying coefficient matrix satisfied by Adjustable weighting matrix output for agile spacecraft maneuver control.

[0052] Furthermore, the Riccati differential equation is solved in S5 to obtain the optimal output of the maneuver-vibration isolation game system and for:

[0053]

[0054] in, for The corresponding first time-varying coefficient matrix, for The corresponding second time-varying coefficient matrix. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 This is a flow chart of a game control method for agile spacecraft maneuvering and low-stiffness vibration isolation of super-static loads.

[0056] Figure 2 A diagram showing the connections between the agile spacecraft, the vibration isolation device, and the hyperstatic load.

[0057] Among them: 1. Excessive static load; 2. Vibration isolation device; 21. Upper platform of vibration isolation device; 22. Lower platform of vibration isolation device; 3. Agile spacecraft. DETAILED DESCRIPTION

[0058] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0059] like Figure 1 As shown, a game control method for agile spacecraft maneuvering and low-stiffness vibration isolation of super-static loads includes the following steps:

[0060] S1: Hypothesis about the relationship between agile spacecraft 3, vibration isolation device 2 and excess static load 1;

[0061] S2: Establish the maneuvering dynamics model of agile spacecraft and the dynamics model of vibration isolation device based on the assumptions;

[0062] S3: Based on the agile spacecraft maneuvering dynamics model and the vibration isolation device dynamics model, a maneuvering-vibration isolation system dynamics model is established;

[0063] S4: Based on the dynamics model of the maneuvering-vibration isolation game system, the performance index function and Hamiltonian equation of the game system are constructed to obtain the Riccati differential equation corresponding to the maneuvering-vibration isolation game system;

[0064] S5: Solve the Riccati differential equation to obtain the optimal output of the maneuver-vibration isolation game system, and complete the game control of agile spacecraft maneuvers and low-stiffness vibration isolation of super-static loads.

[0065] It is assumed in S1 that: the hyperstatic load 1 is mounted on the upper platform 21 of the vibration isolation device, the lower platform 22 of the vibration isolation device is fixedly connected to the agile spacecraft 3, the upper platform 21 of the vibration isolation device and the lower platform 22 of the vibration isolation device are connected with low stiffness, the following maneuver and vibration isolation of the hyperstatic load 1 are realized by the vibration isolation device 2, and the vibration isolation device 2 can output continuous actuation force, such as Figure 2 shown.

[0066] Maneuvering Dynamics Model of Agile Spacecraft in S2 for:

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073] in, For the Agile Spacecraft System Matrix, is the selected agile spacecraft state vector, Input matrix for agile spacecraft, 12-dimensional input vector for the agile spacecraft, is a 6×6 identity matrix, is the agile spacecraft state variable, are the mass and inertia matrices of the agile spacecraft, is the maneuvering control force or torque acting on the agile spacecraft, , , , , and are the generalized coordinates of the agile spacecraft in the inertial system, is the transpose of the matrix;

[0074] The fitted Jacobian matrix of the agile spacecraft maneuvering dynamics model for:

[0075]

[0076] in, Inertial coordinate system Lower vibration isolation device actuator The unit direction vector of The lower hinge point of the actuator is in the aircraft system The position vector of .

[0077] Dynamic model of vibration isolation device in S2 for:

[0078]

[0079]

[0080]

[0081]

[0082]

[0083] in, is the vibration isolation device system matrix, is the state vector of the selected vibration isolation device, Enter the matrix for the vibration isolation device, Active control of load following maneuvers by the vibration isolation device, The vibration isolation device is used to isolate the control force of micro vibration outside the maneuvering signal during the maneuvering process. 12× r The matrix of order, r is the number of actuators in the vibration isolation device, is the first transformation matrix, is the second transformation matrix, is the third transformation matrix, is the mass and inertia matrix of the vibration isolation device, is the installation Jacobian matrix of the vibration isolation device, is the damping matrix connecting the upper and lower platforms of the vibration isolation device, is the equivalent stiffness matrix of the connection between the upper and lower platforms of the vibration isolation device, , , , , and are the generalized coordinates in the inertial system of the superstatic load, , and are the corresponding angular velocities respectively;

[0084] In this embodiment, is the first transformation matrix, is the second transformation matrix, The specific value of the third transformation matrix is:

[0085]

[0086]

[0087]

[0088] in, is a 3×3 identity matrix, is a 6×6 identity matrix, is the conversion matrix from the attitude angle to the angular velocity of the vibration isolation device;

[0089] The installed Jacobian matrix of the vibration isolation device dynamic model is for:

[0090]

[0091] in, The hinge point of the actuator is in the vibration isolation device. The position vector of .

[0092] Combine the agile spacecraft dynamics model and the vibration isolator dynamics model, and take the state variables as , the dynamic equation of the maneuver-vibration isolation game system is obtained.

[0093] Dynamics model of maneuverability-vibration isolation game system in S3 for:

[0094]

[0095] in, is the system matrix of the game system, is the state variable, is the input matrix of the vibration isolation device in the game system, is the input matrix of the agile spacecraft in the game system.

[0096] The mission requirements of the known vibration isolation device are to isolate the micro-vibration transmission of the spacecraft platform, ensure that the vibration level at the super-static load position is as small as possible, and at the same time ensure that the relative position with the spacecraft is as small as possible when the spacecraft maneuvers, and save its own energy as much as possible.

[0097] The performance indicator functions of the game system in S4 include:

[0098] By using the idea of ​​differential games and according to the maneuvering requirements of agile spacecraft, the maneuvering performance index of the hyperstatic load can be constructed.

[0099] Following maneuverability performance index of super static load for:

[0100]

[0101] in, is the state variable function, To control the initial time, To control the terminal moment, , and is the adjustable weighting matrix of the super static load following maneuver index, For time;

[0102] Item indicates the control end time The deviation degree of the hyperstatic load from the agile spacecraft state makes the performance index function smaller in order to obtain faster and more accurate following maneuvering capability; It is the deviation between the excess static load following maneuver and the agile spacecraft maneuver during the maneuver. In order to avoid collision and improve the maneuverability of the vibration isolation device, this item should be as small as possible to make the performance index function smaller.

[0103] Using the idea of ​​differential games, the vibration isolation performance index of the hyperstatic load can be constructed according to the maneuvering requirements of agile spacecraft.

[0104] Vibration isolation performance index for super static load for:

[0105]

[0106] in, , and It is an adjustable weighting matrix for the super static load vibration isolation performance index.

[0107] Item indicates the control end time In the case of micro-vibration under super-static load, this item should be as small as possible to obtain better vibration isolation effect and make the performance index function smaller; It reflects the vibration isolation capability of the vibration isolation device during maneuvering and is only related to the state variable of the excess static load. This item should be as small as possible to make the performance index function smaller.

[0108] The Hamiltonian equation in S4 is:

[0109]

[0110] in, is the first equation, is the second equation, for The corresponding covariate, for The corresponding co-state variables are defined as .

[0111] According to the extreme conditions of the system:

[0112]

[0113] It can be concluded that the optimal control strategy for super-static load maneuvering and vibration isolation is:

[0114]

[0115] Substituting the optimal control strategy into the state equation of the game system, a linear two-point boundary value problem is obtained.

[0116] The Riccati differential equation corresponding to the maneuver-vibration isolation game system in S4 can be derived by the following method:

[0117] Assuming covariates Satisfies the following quadratic form:

[0118]

[0119] In order to make the above formula valid for any All hold true, so there must be a matrix Satisfies the equation:

[0120]

[0121] in, is the adjustable weight matrix for the maneuver control output of the agile spacecraft, For the hypothetical The time-varying coefficient matrix satisfied by . , by integrating the coupled Riccati equation above inversely under this boundary condition, we can obtain .

[0122] Solving the Riccati differential equation in S5 yields , thus obtaining the optimal output of the maneuver-vibration isolation game system and for:

[0123]

[0124] in, for The corresponding first time-varying coefficient matrix, for The corresponding second time-varying coefficient matrix.

[0125] In one embodiment of the present invention, in order to solve the problem that the hyperstatic load carried by an agile spacecraft cannot achieve faster following and cannot achieve good vibration control effect when it is maneuvering, this problem is modeled as a game problem between the vibration isolation capability of the hyperstatic load and the maneuverability, so that when the spacecraft is maneuvering, the vibration isolation device can output two parts of power at the same time, one part ensures that the hyperstatic load installed thereon can achieve faster following, and the other part ensures that the hyperstatic load still has a good vibration isolation effect during the following process.

[0126] Firstly, the dynamics model of spacecraft maneuvering and the dynamics model of vibration isolation device are established respectively. Then, differential game is used as the framework to establish the dynamics model of game system and the performance index function of vibration isolation and maneuvering. Finally, the HJ equation is obtained and solved by optimizing the performance index function, and the state feedback control strategy expression is obtained, which can be used directly online. This method has not been studied in the field of spacecraft micro-vibration control. It has high practicality in real space missions. It can avoid collision inside the vibration isolation device when agile spacecraft maneuvers as much as possible, and realize the follow-up with agile spacecraft under the premise of ensuring the vibration isolation effect of hyperstatic load, which provides a strong guarantee for the application of hyperstatic load on agile spacecraft.

[0127] Compared with other vibration isolation control algorithms, the present invention can achieve maneuver-vibration isolation balance control when the spacecraft is maneuvering, and can still achieve a good vibration isolation effect when the super-static load follows the maneuver; the present invention takes into account the follow-up control of the load during the spacecraft maneuver, and can achieve rapid convergence of the load following the maneuver; the present invention adds performance indicators about the relative position of the spacecraft and the load in the controller design, which can effectively avoid the collision of the low-rigidity vibration isolation device and the load.

[0128] 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 invention.

Claims

1. A game control method for agile spacecraft maneuvering and low-stiffness vibration isolation of super-static load, characterized in that: The following steps are involved: S1: Hypothesis about the relationship between agile spacecraft (3), vibration isolation devices (2), and excess static loads (1); S2: Establish the maneuvering dynamics model of agile spacecraft and the dynamics model of vibration isolation device based on the assumptions; S3: Based on the agile spacecraft maneuvering dynamics model and the vibration isolation device dynamics model, a maneuvering-vibration isolation system dynamics model is established; S4: Based on the dynamics model of the maneuvering-vibration isolation game system, the performance index function and Hamiltonian equation of the game system are constructed to obtain the Riccati differential equation corresponding to the maneuvering-vibration isolation game system; S5: Solve the Riccati differential equation to obtain the optimal output of the maneuver-vibration isolation game system, and complete the game control of agile spacecraft maneuvers and low-stiffness vibration isolation of super-static loads; The S2 agile spacecraft maneuvering dynamics model for: in, For the Agile Spacecraft System Matrix, is the selected agile spacecraft state vector, Input matrix for agile spacecraft, 12-dimensional input vector for the agile spacecraft, is a 6×6 identity matrix, is the agile spacecraft state variable, are the mass and inertia matrices of the agile spacecraft, is the maneuvering control force or torque acting on the agile spacecraft, , , , , and are the generalized coordinates of the agile spacecraft in the inertial system, is the transpose of the matrix; The fitted Jacobian matrix of the agile spacecraft maneuvering dynamics model for: in, Inertial coordinate system Lower vibration isolation device actuator The unit direction vector of The lower hinge point of the actuator is in the aircraft system The position vector of Dynamic model of the vibration isolation device in S2 for: in, is the vibration isolation device system matrix, is the state vector of the selected vibration isolation device, Enter the matrix for the vibration isolation device, Active control of load following maneuvers by the vibration isolation device, The vibration isolation device is used to isolate the control force of micro vibration outside the maneuvering signal during the maneuvering process. 12× r The matrix of order, r is the number of actuators in the vibration isolation device, is the first transformation matrix, is the second transformation matrix, is the third transformation matrix, is the mass and inertia matrix of the vibration isolation device, is the installation Jacobian matrix of the vibration isolation device, is the damping matrix connecting the upper and lower platforms of the vibration isolation device, is the equivalent stiffness matrix of the connection between the upper and lower platforms of the vibration isolation device, , , , , and are the generalized coordinates in the inertial system of the superstatic load, , and are the corresponding angular velocities respectively; The installed Jacobian matrix of the vibration isolation device dynamic model is for: in, The hinge point of the actuator is in the vibration isolation device. The position vector of The dynamic model of the maneuvering-vibration isolation game system in S3 for: in, is the system matrix of the game system, is the state variable, is the input matrix of the vibration isolation device in the game system, is the input matrix of the agile spacecraft in the game system.

2. The game control method for agile spacecraft maneuvering and low-stiffness vibration isolation of super-static load according to claim 1 is characterized in that: The assumption in S1 is that: the hyperstatic load (1) is mounted on an upper platform (21) of a vibration isolation device, the lower platform (22) of the vibration isolation device is fixedly connected to the agile spacecraft (3), a low-rigidity connection is adopted between the upper platform (21) of the vibration isolation device and the lower platform (22) of the vibration isolation device, the follow-up maneuver and vibration isolation of the hyperstatic load (1) are both achieved through the vibration isolation device (2), and the vibration isolation device (2) is capable of outputting continuous actuating force.

3. The game control method for agile spacecraft maneuvering and low-stiffness vibration isolation of super-static load according to claim 1 is characterized in that: The performance index function of the gaming system in S4 includes: Following maneuverability performance index of super static load for: in, is the state variable function, To control the initial time, To control the terminal moment, , and is the adjustable weighting matrix of the super static load following maneuver index, For time; Vibration isolation performance index for super static load for: in, , and It is an adjustable weighting matrix for the super static load vibration isolation performance index.

4. The game control method for agile spacecraft maneuvering and low-stiffness vibration isolation of super-static load according to claim 3 is characterized in that: The Hamiltonian equation in S4 is: in, is the first equation, is the second equation, for The corresponding covariate, for The corresponding covariate.

5. The game control method for agile spacecraft maneuvering and low-stiffness vibration isolation of super-static load according to claim 4 is characterized in that: The Riccati differential equation corresponding to the maneuver-vibration isolation game system in S4 is: in, is the assumed covariate The time-varying coefficient matrix satisfied by Adjustable weighting matrix output for agile spacecraft maneuver control.

6. The game control method for agile spacecraft maneuvering and low-stiffness vibration isolation of super-static load according to claim 5 is characterized in that: In S5, the Riccati differential equation is solved to obtain the optimal output of the maneuver-vibration isolation game system. and for: in, for The corresponding first time-varying coefficient matrix, for The corresponding second time-varying coefficient matrix.

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