Research On Robust Adaptive Control Of Trailing Edge Flaps

The complex working environment of the rotor causes the helicopter to face serious vibration problems.The rotor system with trailing edge flap is an effective vibration reduction control method for the helicopter by controlling the deflection of the flap installed at the outer trailing edge of the blade to change the aerodynamic distribution of the rotor and the response of the blade.In order to reduce the vibration of rotor system,the main research contents of this paper are as follows:Firstly,in order study the rotor vibration control effect of trailing edge flaps,namely the influence of action law of trailing edge flaps on vibration load of rotor system.In the rotor system coordinate,first of all,referring to the papers at home and abroad,the structural dynamics and aerodynamics of rotor system are analyzed.The state space model is established with blade flap,lag,torsion angle and angular velocity as state variables,trailing edge flap deflection angle as input and hub vertical force as output.Then,in order to facilitate the subsequent controller design,the model should be simplified,and the specific expression of the model is obtained combined with the system identification method.The effectiveness of the model is verified by simulation for the subsequent vibration reduction controller design.Secondly,considering the influence of model uncertainty on vibration reduction of rotor system model,the vibration reduction control method of rotor system based on H-infinity is studied.First of all,the control objective of the H-infinity vibration controller is to reduce the vibration and minimize the deflection angle of the trailing edge flaps;Then considering the above objectives,the initial weight function of the controller is designed,and the controller is solved based on Riccati equation to obtain the expression of the controller;Finally,the optimal controller is obtained by continuously adjusting the weight parameters.Simulation verifies the robustness and vibration reduction effect of the controller based on the nominal model and the model with ± 10% model uncertainty.Furthermore,considering the influence of bounded but unknown external disturbances on the vibration reduction of rotor system,the vibration reduction control method based on adaptive multivariable finite time disturbance observer is studied.Firstly,an adaptive multivariable super-twisting sliding mode finite time disturbance observer is designed to realize the on-line estimation of external disturbances of rotor system;Then based on the homogeneous theory,the synthesis design of the controller observer system is completed,and the stability of the closed-loop system is analyzed based on the homogeneity and Lyapunov stability theory.Finally,the effect of the observer-controller integrated control on the vibration reduction of the rotor system and the ability of disturbance compensation are verified by simulation.