Implicit Lyapunov Robust Tracking Control of Oscillatory-Base Manipulators

This paper is concerned with the robust tracking problem of oscillatory-base manipulators in the non-inertial task space. A novel control strategy based on the implicit Lyapunov method is proposed. Firstly, robust feedback linearization of the system dynamical model is carried out relying on the computed torque method, which could be interpreted as a proportional derivative control with continuous time-varying gains, is used to stabilize the linearized uncertain system. Moreover, stability of the closed-loop perturbed system is theoretically proved. Finally, hardware experimental results indicate that the proposed controller offers superior robustness against the base-oscillation-induced uncertainties. Results also demonstrate the advantages of the proposed method in that neither measurement nor prior knowledge of the uncertainties is required in the implementation.