Research On Attitude Tracking Control Methods For Agile Satellite

Agile satellite has many advantages,such as strong maneuverability,wide coverage and multithreaded,which has become the focus of the research of space agencies at home and abroad.The task distribution of agile satellite is wider than that of traditional satellite,and it is not limited to sub-satellite point.Therefore,the agile satellite control for different tasks becomes the difficulty of the research.Because the agile satellite moves in a large range frequently,it is not realistic to control the whole life cycle,the whole mode,the whole process and the whole attitude only on the ground.Therefore,based on the analysis of the the agile satellite’s working characteristics,this work studies the robust fault-tolerant tracking control,the anti buffeting with attitude tracking control etc.,in order to eliminate the influence of attitude pointing accuracy caused by the attenuation of accuracy and stability of measuring elements caused by attitude agility.The main contents of this work are as follows:1)Agile satellite modeling analysis.Establish the kinematics and dynamics model of agile satellite in orbit;Analysis motion characteristics and working process,and present the design of support controller.2)Aiming at the aging or damage of the actuator caused by frequent agile maneuvers,this work designs a robust fault-tolerant attitude tracking system for agile satellites.A finite time adaptive sliding mode control law is designed to meet the requirements of attitude orientation and imaging time of agile tasks,which can effectively guarantee the attitude control of tasks with time constraints when the actuator is incomplete.The adaptive robust control is designed to meet the requirement of agile attitude in the case of damage of the self-propelled mechanism,which ensures the effective attitude tracking of the target in the case of overcoming the output limitation of the actuator.3)Aiming at the chattering problem caused by sliding surface,an adaptive attitude tracking controller is designed.Based on the theory of sliding mode control,the algorithm optimizes the design of sliding mode surface and effectively reduces chattering.Finally,the stability of the sliding surface is proved and the simulation of the controller is completed.In conclusion,this work focuses on the robust fault-tolerant attitude control of agile satellite and the anti-chattering attitude tracking control of agile satellite.Adopt the linear sliding mode control strategy to realize the finite time convergence of satellite attitude error,and design a new control algorithm with the help of hyperbolic tangent function to effectively reduce the impact of chattering.This method can provide a control solution for agile satellite development.