Abstract:

The problem of coupled relative orbit and attitude for approaching to a non-cooperative target is researched. With the consideration of coupled factors of control command, system uncertainty and disturbance, the chattering free adaptive second order non-singular terminal sliding mode(SONTSM) control law is proposed. Firstly, the relative position and relative attitude model based on the line of sight coordinate frame and body coordinate frame respectively is established. Based on the terminal sliding mode theory and inspired by the high order sliding mode control, the controller overcomes the chattering phenomenon that appears in the traditional sliding mode, which also has the advantages of rapid convergence, high precision, strong robustness and smaller energy consumption. Based on the Lyapunov theory, the system stability is proved. Simulation results demonstrate the validity and effectiveness of the proposed control law.