Adaptive control of mixed rigid/flexible joint robot manipulators based onvirtual decomposition

A modular approach named virtual decomposition is applied to adaptive contr ol of robot manipulators with mixed rigid/flexible joints. The system is vi rtually decomposed into the held object, the links, and the rigid/flexible joints. Each subsystem is controlled independently with decentralized param eter adaptation, while the dynamic interactions between the subsystems are completely represented by virtual power hows (VPF's) which are independent of the dynamics of the subsystems. The equivalence between a rigid joint co ntrol and a flexible joint control is established, since they dedicate the same dynamic interactions with their connecting links. Each subsystem is as signed a nonnegative accompanying function which takes care of its dynamics . The system Lyapunov function is formed just by considering the VPF's with out considering the dynamics of the subsystems. Lyapunov asymptotic stabili ty is guaranteed. Finally, simulation results are presented.