Robust nonlinear feedback control for robotic manipulators

Nonlinear feedback control algorithms for manipulators utilise the complete (coupled and nonlinear) dynamic model to decouple the robot joints. In this framework, we present a comparative evaluation of the computed-torque and direct-design control algorithms, and outline the practical problems introduced by modelling inaccuracies, unmodelled dynamics and parameter errors. We then formulate the α-computed-torque nonlinear feedback control algorithm which is robust in the presence of the aforementioned error sources. Numerical experiments with cylindrical robots confirm the robustness and applicability of our α-computed-torque algorithm.