Dynamics Analysis Of Two-dimensional Wing Active Flutter Suppression System With Time-delay Feedback

Currently, active control has become an important method of flutter suppression. Past studies oftenignore time delay in the system; however, recent research shows delay has significant impact on fluttersuppression systems. The thesis researches on active flutter suppression of a two dimensional wingsection system by using ultrasonic motor. Firstly, Using theoretical analysis and experimental methods,the modeling and control of ultrasonic motor are analyzed. Secondly, dynamic equations of thetwo-dimensional wing are derived, a control-law is designed for its flutter control, and the influence ofthe system is investigated under different plunges pitching nonlinear spring. Finally, the dissertationanalyzes the stability of a flutter suppression systems containing delay, and then design the control-law.The main works of the thesis are as following.(1)The core of the two-dimensional wing flutter suppression control system is DSP. In order to getthe mathematical model of ultrasonic motor, the ultrasonic motor control experimental platform isdesigned by using DSP and Matlab joint development method. The PID, fuzzy-PID and fuzzyimmune-PID control algorithm are designed. Experiments and numerical simulations show that thefuzzy immune-PID has good control effectiveness.(2)A three degree of freedom two-dimensional wing with control surface deflection for activeflutter suppression experimental platform is designed. Dynamic equations of the two-dimensional wingare derived, where Theodorsen unsteady aerodynamics is adopted. A sub-optimal control law isdesigned for its flutter control. Numerical simulation shows that using ultrasonic motor can effectivelysuppress flutter, and critical flutter speed of the system is increased by22.2%.The influence of theplunge and pitching nonlinear spring on the motion of the system is discussed.(3) Considering a number of uncertainties factors in the system, and controllers are designed.Numerical simulation shows that both controllers have good control effectiveness, the controller hasa better result compared with controller. The robust controller is used to analyze the stability ofsystem, where the control surface contains the gap.(4)The stability of the two degree of freedom wing section system containing time-delayedfeedback is analyzed by using generalized Sturm theory. Using equivalent conversion method, theequation changes into the same dimension equation of state without the time delay. A sub-optimalcontrol law is designed for its flutter control. Numerical simulations show that the method caneffectively control system containing time delays.