Research On Magnetorheological Damper Semi-active Vibration Isolation Oriented To Helicopter Seating System

The major factors that threaten pilot’s health and safety are the vibration in theflight and the shock in the crash of helicopters. It is convenient and effective to installmagnetorheological (MR) damper and adopt appropriate control method in order toimprove the vibration isolation performance of helicopter seating system. With the goalof reducing vibration and mitigating shock, MR dampers, buffers and linear quadraticregulator (LQR) control algorithm are employed to design a MR damper semi-activehelicopter seating system in present thesis. The rationality and effectiveness of thissystem are verified by both simulation and experiment.Hyperbolic tangent model, BPNN model and ANFIS model of MR damper aredeveloped; BPNN model and ANFIS model of MR damper controller are designed. TheMR damper dynamical test is carried out. Parameters optimization of MR dampermodels and MR damper controller models are conducted based on the test data. The MRdamper system model is constructed from the selected models with best overallperformances. The reliability of the MR damper system model is verified by testing theaccordance between the simulation results and the experiment data.Seating suspension structure and installation location of MR dampers and buffersare confirmed based on the vibration isolation requirements and working environment.The helicopter seating system’s mathematical model is also derived. System controllermodel is designed using skyhook and LQR algorithms. The model with the bestperformance is chosen as the system controller by dynamic simulation.Passive control, active control and MR damper semi-active control seating systemmodels are established in MATLAB/Simulink. Simulation is run under input excitationof step displacement, sinusoidal displacement and pulse force. Semi-active seatingsystem is proved to be the effective in reducing vibration and shock comparing to othercontrol models by using seating suspension load acceleration as the evaluation index.The impact about the change of seating system parameters is analyzed.The set-up of helicopter seating system control bench is built based on the seatingsystem model. The step excitation is measured by using xPC Target real-time controltechnology from Simulink block diagram. Result indicates that the MR dampersemi-active helicopter seating system possesses obvious damping effect, which providesguidelines for the design of helicopter seating system.