Experimental results for nonlinear decoupling control of flexible multi-link manipulators

This paper focuses on the experimental implementation of an observer-based decoupling control strategy for tip-position tracking of a class of multilink flexible manipulators. The control strategy is based on output redefinition and input-output decoupling that was studied by the authors in an earlier paper. Since the rates of change of flexible modes are required, a nonlinear observer is implemented to estimate these variables. Experimental results are given for the case of a two-link flexible manipulator that further confirm the theoretical and simulation results. The closed-loop performance under different observation schemes is evaluated and compared to the case when conventional methods are used.