Active suppression of freeplay aeroelastic vibrations of ailerons by robust control methods with incomplete measurements

Abstract

PurposeThe purpose of this paper is to analyze the active suppression of the nonlinear aeroelastic vibrations of ailerons caused by freeplay by robust H∞ and linear quadratic Gauss (LQG) methods of control in case of incomplete measurements of the state of the system.Design/methodology/approachThe flexible wing with nonlinear aileron with freeplay is treated as a plant-controller system with H∞ and LQG controllers used to suppress the aeroelastic vibrations. The simulation approach was used for analyzing the impact of completeness of measurements on the efficiency and robustness of the controllers.FindingsThe analysis shows that the H∞ method can be effectively used for suppression of nonlinear aeroelastic vibrations of aileron, although its efficiency depends essentially on completeness and types of measurements. The LQG method is less effective, but it is also able to prevent aileron vibrations by reducing their amplitudes to acceptable, safe level.Research limitations/implicationsOnly numerical analysis was carried out for the problem described; thus, the proposed solution is of theoretical value at this stage of analysis, and its application to the real suppression of aeroelastic vibrations requires further research.Practical implicationsThe work presents a potentially useful solution to the problem of interest and results are a theoretical basis for further research.Social implicationsThis work may lead to a hot debate on the advantages and drawbacks of the active suppression of vibrations in the aeroelasticians community.Originality/valueThe work raises the important questions of practical stabilizability of the nonlinear aeroelastic systems, their dependence on completeness and types of measurements and robustness of the controllers.