Adaptive Feedback Control Algorithm for Flutter Boundary Expansion

This paper introduces an adaptive flutter suppression control algorithm which is based on the iterative estimate of the aeroelastic plant and design of the feedback controller. In this algorithm, the dual-Youla parametrization is implemented as an essential part to estimate the open loop aeroelastic model from the closed loop experiment. The advantage of utilizing the dual-Youla parametrization for the aeroelastic plant estimation is that the possible unstable open loop aeroelastic model could be estimated in the situation where aeroelastic dynamic system is operating above the flutter speed. Based on the estimated open loop model, a new controller could be designed using the standard controller design techniques to extend the flutter envelope boundary. By iteratively estimating the open loop aeroelastic model and designing the controller, the flutter boundary could be expanded. Application of this adaptive control algorithm to the pitch-plunge aeroelastic system shows that the flutter boundary can be expanded by 80%.