An improved reaching law of SMC for spacecraft tracking system

Spacecraft tracking system is considered as a discrete-time system, and an improved reaching law of SMC and controllers for three axes in spacecraft have been investigated in this paper, in order to reduce chattering caused by traditional sliding mode reaching law. Theory proves that the improved reaching law can ensure the stability of spacecraft tracking system and eliminate the chattering phenomenon, and the reaching speed is analysis in detail. Simulation results show that compared with exponential reaching law and classical variable speed reaching law, the proposed reaching law has better suppress chattering effect and dynamic performance.