Active Disturbance Rejection Control For Spacecraft Attitude And Orbit System

The high performance control of spacecraft attitude and orbit system is an important basis for space activities and future deep space exploration in China.In order to ensure the on-orbit service of the space mission smoothly,the reliable control algorithm for making the spacecraft in the complex space environment more lasting,stable and high-quality on-orbit operation is urgent.This paper focuses on the six-degree-of-freedom relative attitude and orbit motion control of two spacecraft formation systems.The related control strategies can be widely applied to a variety of close-range operational space missions,such as arresting,hovering,flying around,companion flying,and on-orbit fuel replenishment.Firstly,the dual quaternions are used to describe the relative orbit motion and attitude motion between the target spacecraft and the service spacecraft.Then,in view of the unmeasurable linear and angular velocities between the service spacecraft and the target spacecraft,as well as the uncertainty of the mass and inertia of the service spacecraft,a variety of six-degree-of-freedom active disturbance rejection control methods are designed.In order to avoid the problem of the coupling influence between the attitude and the orbit in the traditional description method,this paper uses the dual quaternion mathematical tool to simultaneously describe the orbital motion and attitude motion of the spacecraft.Within the framework of dual algebra,the integrated orbit and attitude kinematics and dynamics are modeled.Compared with other helical transform description tools,dual quaternion mathematical expression is more concise and effective,and avoids the complex mixed operation problem between two kinds of motion parameters.Aiming at the attitude and orbit control problem when the linear and angular velocity information between the service spacecraft and the target spacecraft cannot be measured,a 6-DOF extended state observer based on the dual quaternion is designed,to provide the accurate linear velocity and angular velocity estimation.Then the error rate based on the refactoring information from the extended state observer is proposed.However,the traditional extended state observer has slow convergence speed and poor filtering performance.Introduced the idea of tracking differentiator with convergence and filtering performance,a 6-DOF extended state observer with fast convergence and filtering performance is proposed.Finally,the effectiveness of the method is verified by numerical simulation.In view of the attitude and orbit control problem when the quality and inertia parameters of service spacecraft are uncertain,an active disturbance rejection generalized predictive controller is presented by combining the technique of active disturbance rejection control and generalized predictive control.Firstly,the extended state observer is employed to estimate and compensate the information different from integral part series of the spacecraft attitude and orbit system,such that an integrator form can be obtained to serve as the model for generalized predictive controller to design the virtual control rate.Through analyzing the solving process of Dioaphantine equation,the analytical solution form of step response coefficient matrix can be obtained directly.This control scheme avoids the poor adaptability caused by fixed parameters in active disturbance rejection control strategy,and the increased randomness and nonlinearity of closed-loop system due to parameter identification in generalized predictive control strategy.Finally,the simulation verifies the effectiveness of the proposed method for spacecraft attitude and orbit system.