Adaptive reaction control for space robotic applications with dynamic model uncertainty

This paper proposes adaptive control methods based on reaction dynamics for different types of space robotic systems. Reaction dynamics feature the dynamic coupling between an actively operated part and a passively moving part in a multibody robotic system. The reaction dynamics have been used to develop trajectory tracking control of a free-floating space robot or vibration suppression control of a flexible-structure-based manipulator system. However, the presence of dynamic parameter uncertainties degrades the control performance of the above-mentioned methods, since the methods require accurate values of both kinematic and dynamic parameters. To resolve such parameter uncertainties, practical adaptive control methods are proposed in this study. The proposed methods overcome two inherent difficulties in the adaptive control design of space robotic systems, such as nonlinear parameterization of the dynamic equation and uncertainties in coordinate mapping from Cartesian space to joint space. To confirm the validity of the proposed methods, numerical simulations are carried out using three-dimensional realistic models of two types of space robotic systems.