Decentralized control of nonlinear robot manipulators

Robot manipulators have highly nonlinear dynamics. Therefore the control of multi-link robot arms is a challenging and difficult problem. In this paper a nonlinear dynamic model is first presented for an x-axis robot arm. Then a linearized model is obtained for it. The linearized model is then considered as an n-controller large-scale system. The notion of decentralized stabilization has been introduced and applied to the robot arm. Controllers considered are pd, pid and pd plus a feedforward (inverse dynamics). Numerical simulation for decentralized control of a 3-axis puma arm will also be included.