Trajectory tracking control for robot manipulators with mixed joints via virtual decomposition

It is always difficult to establish dynamics expressions via energy-work balance principle for multi-degree-of-freedom robot manipulators with mixed rigid/flexible joints. To solve such problem, a virtual decomposition control based trajectory tracking approach is proposed for robot manipulators with mixed joints. First, the robot manipulators with mixed joints is virtually decomposed into links and rigid/flexible joints. Secondly, subsystem model and control law corresponding to each link and joint is established. Then, strict system stability analysis is given according to the theory of virtual stability and Lyapunov stability. Finally, numerical simulations are made to verify the proposed approach.