Robust Control for the 3 DoF Aeroelastic Wing via TP Model Representation

Abstract

Several control design approaches were utilized recently for actively stabilizingthe 2 and 3 degrees-of-freedom (DoF) aeroelastic wind section, whichhave structural nonlinearities. The present paper focuses on the stabilizationof the 3 DoF model. The proposed control design strategy takes into accountthe uncertainties of the trailing edge dynamics and robust output feedbackcontrol is designed where the only measurable state variable is the pitch angle.Beside robust asymptotic stability, the controller has to fulfill criteria relatedto the bound of the l2 norm of the control signal. The control design is basedon Tensor Product (TP) type convex polytopic representation of the 3 DoFaeroelastic wing section model and all of the control performance objectivesare formulated via Linear Matrix Inequalities (LMIs). The convex TP typepolytopic model is obtained via TP model transformation as the first step ofthe design and the feedback and observer gains are derived via LMI basedconvex optimization as the second step. The resulting controller and observertakes the polytopic structure of the TP type convex NATA model. The derivedcontroller and observer structure is evaluated and validated via numericalsimulations.