TIP TRAJECTORY TRACKING FOR MULTILINK FLEXIBLE MANIPULATORS USING STABLE INVERSION

The recently developed stable inversion theory for nonminimum phase no nlinear systems is applied to output tracking for multilink flexible r obot manipulators. Tile stable inversion theory and a numerical soluti on to stable inverses are briefly reviewed. Forward dynamics of a two- link flexible manipulator with tip position as the output is then give n using the assumed modes method. From that, rm inverse model is deriv ed and a two-point boundary value condition is set up. This condition guarantees that the inverse solution for a given desired Lip trajector y will be stable regardless of the fact that a flexible manipulator is a nonminimum-phase system. The stable inverse is incorporated into an output tracking controller that uses only joint-angle feedback. Excel lent tracking is achieved with no transient or steady-state errors and no internal vibration buildup.