Research On Vibration Control Of Wind Tunnel Model Based On Time Delay And Fuzzy Sliding Mode

Vibration is a phenomenon commonly found in nature.In the wind tunnel test,the vibration of the aircraft model seriously affects the test accuracy of the wind tunnel test and the angle of attack of the aircraft model test.Sometimes it even damages the wind tunnel operation and limits the development of new aircraft.Research on vibration control of aircraft models using a wind tunnel test aircraft model vibration suppression system is based on high-voltage piezoelectric ceramic actuators.The time delay problem in control system mainly caused by the filter will seriously affect the effect of the vibration control,and sometimes even cause vibration to cause the failure of the vibration control device.In the wind tunnel environment,nonlinear problems in vibration control are caused by the different wind tunnel test conditions and the different test requirements of different wind tunnels and the hysteresis of piezoelectric actuators.This paper aims at the above-mentioned time-delay and nonlinear problems,and carries out experimental research on vibration control of wind tunnel model based on time-delay compensation and fuzzy sliding mode control algorithm.(1)A cantilever beam system composed of fixed-end end machete,struts,force balance,and aircraft model is briefly introduced to analyze the causes of aircraft model vibration based on the current research status of vibration suppressor and vibration control algorithms for wind tunnel test aircraft models.And the characteristics of the first-order self-excited vibration,combined with the vibration characteristics to obtain the second-order transfer model of the cantilever beam vibration system.(2)The causes and effects of the time lag in the vibration control of the aircraft model are analyzed,and the identification of the time delays after the fixed frequency and variable frequency signals are processed through the control process is realized.According to the size of the identified time delay,the LQR control algorithm based on time delay compensation is designed and the corresponding control program is written.Bought suitable experimental apparatus and built wind tunnel test model of an aircraft vibration suppression test system as well.Using the ground experiment to obtain the LQR control algorithm considering the time delay compensation can suppress the vibration more stably and effectively than the LQR control algorithm without considering the time delay,and has a better control effect.(3)The application of sliding mode variable structure control in wind tunnel test aircraft model vibration control is studied.The fuzzy sliding mode adaptive vibration control algorithm is designed and tested in the wind tunnel test and humming test.The control system can increase the system damping ratio to 8.125 times the original.In the case of certain wind speed step angle of attack and certain wind speed continuous angle of attack,the vibration acceleration of the aircraft model is suppressed to within 10% and the angle of attack angle of the wind tunnel test is increased from the original 4° to 10 °,which is 6° higher than the original,and it is verified that the algorithm can effectively control the vibration of the aircraft model,increase the angle of attack of the wind tunnel test of the aircraft model,and ensure the accuracy of the test measurement and the purpose of safe operation of the wind tunnel.