Adaptive nonlinear attitude tracking control for rigid spacecraft with input constraints, harmonic disturbances and parameter uncertainties

This paper addresses the attitude tracking control problem for rigid spacecraft with input constraint, parameter uncertainties and harmonic disturbances. First, by using Modified Rodrigues Parameter(MRP), the kinematic and dynamic models of the rigid spacecraft are introduced. A class of sinusoidal disturbances with known frequencies but unknown amplitudes and phase angles are considered. Second, by combining a nonlinear proportional-derivative(PD) control, an adaptive control part and hyperbolic tangent function part are proposed to guarantee the globally asymptotic convergence of attitude tracking despite the presence of control input constraint, parametric uncertainties and external disturbances. The internal model control is utilized to identify the harmonic disturbances. The parameter uncertainty caused by the unknown inertia matrix is handled by combining the semi-tensor product and adaptive control method. In particular, the nonlinear PD control term is designed to achieve better tracking performance with shorter settling time and smaller/no overshoot. A detailed stability analysis of the resulting closed-loop system is included. Finally, numerical simulation results for the rigid spacecraft show good performances, which validate the effectiveness and feasibility of the proposed schemes.