Tip trajectory tracking for a one-link flexible manipulator using causal inversion

Tip trajectory tracking for a flexible link robotic manipulator is a challenging problem. Due to the nonminimum phase nature of the system, existing methods encounter difficulties achieving high level performance. The classical causal inverses proposed by Hirschorn (1979) result in unbounded solutions to the inverse problem when the zero dynamics are unstable. Stable inversion introduced by Chen and Paden (1992) obtains bounded but noncausal inverses for nonminimum phase systems. In this paper, a causal inversion-based controller is applied to a one-link flexible manipulator. Simulation results demonstrate the effectiveness of the new causal inversion approach in output tracking.