Geometric adaptive robust sliding-mode control on SO(3)

This paper addresses the rigid body attitude tracking control on the manifold SO(3) . This modeling scheme can avoid the singularity and ambiguity associated with local parameterization representations such as Euler angles and quaternion. A robust and almost global asymptotic stability control system is designed considering the parameters uncertainty and external interference. Based on the coordinate-free geodesic attitude error scalar function with its deduced attitude and velocity error vectors, a geometric asymptotic convergent sliding-mode surface is designed firstly. Then, a geometric sliding-mode controller is introduced to enhance the robustness of the system for the low-amplitude fast-time-varying disturbances. Moreover, in order to attenuate the effect of the parameters uncertainty and slow-time-varying disturbance, two adaptive functions are employed to obtain the feedforward compensation. Comparison studies and simulation results show that the proposed controller is more practical with a high accuracy, strong robustness, less chattering and simple structure.