High Accuracy attitude regulation of Spacecraft Using Arm Motion

摘要

Various path planning algorithms have been used to deduce optimal manipulator joint trajectories for spacecraft attitude regulation using arm motion. However, few papers have considered the unexpected factors when applying those planned path into actual situations. Even though conventional feedback control would drive the arm dynamics to the desired one, this only appears when time evolves to infinity which means during some time the actual joint paths deviate from the desired ones. However, the spacecraft attitude change is related to the entire process of arm motion. So, even a small deviation of the actual joint movement from the desired one would cause the failure of spacecraft attitude regulation task. In this paper, sliding mode control technique is adopted to force the actual joint moves along the desired trajectory from the start. Further, saturation function is used to eliminate the chattering phenomenon. Moreover, the relation between attitude regulation accuracy and controller parameters is deduced which gives instructions in tuning the controller parameters. In the end, numerical simulation is conducted to show the feasibility of the proposed controllers.