Delayed sub-optimal control for active flutter suppression of a three-dimensional wing

In this paper, delayed sub-optimal control based on partial-state feedback for flutter suppression system involving time-delay is investigated, and the effectiveness of the sub-optimal controller is compared with the optimal controller based on full-state feedback. Firstly, the aeroservoelastic (ASE) model of the flexible wing with control surfaces is given, and the method to dispose the time-delay in the control input is introduced. Then, the determination of the importance of each state in control feedback is studied using the second-order sensitivity of the performance index with respect to the control gain. Finally, the effectiveness of sub-optimal controller is compared with optimal controller through numerical simulations. Simulation results show that the importance of states can be effectively determined by the second-order sensitivity, and the delayed sub-optimal controller can achieve a control effect quite close to the delayed optimal controller. The order of the delayed suboptimal controller designed in this paper is lower, so it shows more engineering significance.