Robust adaptive control of free-floating space robot based on fuzzy compensation

Abstract

This paper proposes an adaptive controller for a free-floating space robot (FFSR) in the presence of kinematic and dynamic model uncertainties. Because of high dynamical coupling between the actively operated manipulator and the free-floating base, two inherent difficulties exist, such as non-linear parameterization of the dynamic equation and both kinematic and dynamic parameter uncertainties. In order to compensate these uncertainties, we use the fuzzy logic system (FLS) that has the capability to approximate any nonlinear function. The proposed adaptive controller does not involve complex calculations, but it is still possible for the system to generate a suitable input torque and a compensator to overcome the uncertainties. Then, the stability is proved and the structure of the control method is given. To verify the validity of the proposed method, a computer simulation of a two-link planar FFSR is carried out.