Design of structured discrete-time LPV gain-scheduling controllers through state augmentation and partial state feedback

A method to design discrete-time linear parameter-varying (LPV) gain-scheduling controllers with prescribed order through state augmentation and partial state feedback is presented. Prescribed polytopic linear parameter-varying (pLPV) dynamics are added to the plant for the control design using state augmentation. Static state-feedback gains are calculated via convex linear matrix inequalities (LMIs) and interpolated with pLPV techniques. The resulting controller consists of the prescribed pLPV dynamics and the time-varying gains. The order of the controller is fixed and reduced compared to existing approaches. As an example, a sixth-order controller for suppression of a harmonic disturbance with three time-varying frequencies is designed and implemented in real time in an active vibration control (AVC) test bench.