Energy to peak control of LPV systems with application to rotorcraft ground resonance

Energy to peak control problem for linear parameter varying (LPV) systems involves the design of a stabilizing controller that guarantees satisfaction of time domain L_∞ constraints for all bounded energy disturbances and admissible parameter trajectories. Sufficient conditions in terms of LMIs for the synthesis of parameter dependent controllers with LQG structure are given. As an application, the ground resonance problem in rotorcraft is formulated as an energy to peak control problem. Time domain control objectives include safety limits on rotor tip displacements and saturation limits on swashplate motions. An LPV model of Cobra stick model (CSM) is identified first using data from closed loop experiments. Then, an energy-to-peak controller scheduled with respect to RPM was designed from the identified model. Experimental results from CSM facility are presented. The approach offers a fast and economical means to develop LPV models and design active controllers for rotorcraft aeromechanical instabilities