Spacecraft Attitude Tracking Control Based On Backstepping

Space technology plays an important role in human development and the future,with significant implications for national security and technological progress.As a typical strongly coupled nonlinear complex system,the attitude control problem of spacecraft is one of the core issues in spacecraft control.To meet increasingly complex mission requirements,the attitude constrained control method of spacecraft has received extensive attention and research.However,there are still many issues to be studied,such as unknown external disturbances,“differential explosions” in backstepping methods,and actuator saturation.Therefore,based on the attitude error model of spacecraft rendezvous and docking scenarios,this paper conducts in-depth research on the attitude constrained problem and the solutions to the above issues based on backstepping methods.The main research contents of this thesis are summarized as follows:Firstly,an attitude error model of spacecraft rendezvous and docking scenarios is established.The backstepping method is used to study the attitude tracking control problem of spacecraft,and the stability of the system is proved by the Lyapunov stability theorem.Secondly,aiming at the attitude constrained problem during the maneuvering process of spacecraft,a controller is designed based on the backstepping method and the preset performance concept,using an exponential performance function to preset the tracking attitude error response process.An adaptive law is proposed considering external disturbances,and the stability of the designed adaptive controller is proved by the Lyapunov stability theorem.Finally,in the same context of the attitude constrained problem of spacecraft,the characteristics of several different forms of barrier Lyapunov functions are pointed out.Considering that the use of the tangent barrier Lyapunov function in the actual system can greatly improve the calculation speed on a processor with a CORDIC algorithm hardware unit,a backstepping method-based controller is proposed using the tangent barrier Lyapunov function for attitude constraint design.To solve the differential explosion problem in the backstepping method design,the dynamic surface method is used to optimize the controller design,replacing the time-delayed differential operation with a simple algebraic calculation.Aiming at the saturation problem of spacecraft control torque,an anti-saturation controller was proposed based on dynamic surface control using hyperbolic tangent saturation function.Aiming at the saturation problem of spacecraft control torque,an anti-saturation controller was proposed using hyperbolic tangent saturation function based on dynamic surface control,which solved the problem of actuator saturation.