Research On High-order Harmonic Control Of Rotor Vibration Based On Fuzzy Neural Network

In order to further reduce the vibration level of the helicopter,the active control technology of the rotor vibration has been highly valued.Among them,the individual blade control(IBC)independently applies high-order harmonics to each blade by an actuator,which can improve the aerodynamic environment of the blade and effectively reduce the vibration load of the hub.In this thesis,a comprehensive model of helicopter rotor aeroelastic dynamics is established,which is used as the control object to analyze the influence of second-order harmonics on the vertical vibration load of the hub,and the fuzzy neural network PID control technology is adopted to suppress the vertical vibration load of the hub..The rotor structural dynamics model based on the Hamilton energy variation principle and the medium deformation beam theory is established firstly,and the aerodynamic model based on the dynamic inflow model and the Leishman-Beddoes unsteady aerodynamic model is established.The structural finite element method and the direct numerical integration method are used to calculate the vibration response of the rotor to determine the vibration load of the hub,and by the influence of the second harmonic amplitude and phase on the rotor hub is analyzed.Combining the fuzzy neural network with conventional PID,the fuzzy neural network PID controller is obtained.Its biggest feature is to use the self-learning ability of fuzzy neural network to adjust the parameters of the PID controller.By analyzing the change value of the 3/rev component of the vertical load of the helicopter in the forward flight state before and after the application of the control,it is verified that the fuzzy neural network PID controller established in this thesis can achieve the effect of active vibration control.Taking the helicopter forward flight as an example,it can be obtained through simulation analysis that the 3/rev vertical force of the hub is reduced during the whole control process.After 40 control calculations,the vibration reduction effect of the 3/rev vertical force of the hub reaches the expected level.The simulation process shows that the fuzzy neural network PID control has high efficiency,good stability and fast convergence.