HAMILTONIAN ADAPTIVE-CONTROL OF SPACECRAFT

Robotic spacecraft have the potential of considerably reducing the costs and risks involved in the commercial and scientific exploitation of space. The inherent nonlinearity of their dynamics, however, makes the accurate and effective control of such systems a significant challenge. Furthermore, while spacecraft can be expected to handle objects of masses and sizes comparable to or larger than their own, such tasks involve by nature large dynamic uncertainties, and therefore are likely to require effective adaptive capabilities. This paper proposes a new approach to the accurate attitude tracking control of rigid spacecraft handling large loads of unknown mass properties. The method, based on the construction of a physically motivated Lyapunovlike function, is inspired from the adaptive robot control algorithm of Slotine and Li [18], and presents similar advantages over techniques based on inverse dynamics in terms of simplicity, easier approach to robustness issues, and adaptive capabilities. The approach is illustrated in simulations. © 1990 IEEE