Colocated and noncolocated control design via μ-synthesis for flexible manipulators

Sensor and actuator locations play an important role in the control of flexible manipulators. Colocated and noncolocated controllers are designed using μ-synthesis technique for an experimental flexible arm testbed at the University of Minnesota. A nonlinear, dynamic model of the flexible arm is linearized to generate the control design model. Discrepancies between a linear model and the original dynamical model are modeled as uncertainties and included in the μ-framework. It is observed, theoretically and experimentally, that the addition of tip sensing dramatically improves the tip tracking performance and robustness. The robustness of the noncolocated controllers to variations in the control design model is verified theoretically and experimentally