FAT-based Immersion and Invariance Adaptive Control for Rigid Body Attitude

For the presence of various uncertainties in rigid-body systems, a function approximation technique (FAT) based immersion and invariance (I&I) adaptive control method is proposed for rigid body attitude control in this paper. The system model’s uncertainty terms are aggregated into external disturbances and parameterised using a set of weighted selected basis functions, the weights of these functions are estimated using the immersion and invariance method. Based on the proposed method, a control law based on terminal sliding mode is designed, the effectiveness of the proposed method is verified through stability analysis. Finally, the feasibility of the method is demonstrated through simulations of rigid body attitude under various uncertainties, and it can be effectively applied in the attitude control of rigid body such as vehicles, spacecraft and robotic arms.