Robust trajectory tracking for manipulators with joint flexibility via backstepping

Robust adaptive control for multi-link manipulators with joint flexibility is considered. The scheme is presented under the assumption that the Coriolis, centrifugal, gravity, joint flexibility, friction terms, actuator inertia matrix, torsional damping coefficients, and the disturbances in the manipulator dynamics are completely unknown. Only the inertia matrix for the rigid links is known. The objective of the control design is to robustly track a reference model. A robust adaptive control under strict matching is established and applied to the control design of multi-link manipulators via backstepping. The main contribution of this paper is to avoid over-parametrization, to include more parametric uncertainties, and to present a design methodology which allows the presence of uncertainties and disturbances bounded by general nonlinear functions