Adaptability Study Of Semi-active Inertial Damper For Railway Vehicle

Nowadays,China’s high-speed trains is developing rapidly for higher operating speed and longer operating distance,the conventional suspension design method of parameter optimization,which is usually performed for a single working condition is difficult to meet with the current requirements of large operating speed range and cross-line operation of railway vehicles.Currently,since intelligent material technology and computer technology have stepped into a new stage,adapting novel semi-active suspension to improve the dynamic performance of vehicles at different speeds and improve their line adaptability is a potential research field in high-speed train suspension technology.This thesis aims at a certain type of semi-active eddy current inertial damper for railway vehicles.Dynamic performance of the damper is tested on a hardware-in-the-loop test rig of railway vehicle suspension elements,including its force-displacement response curve,forcespeed response curve,dynamic stiffness,dynamic damping,energy consumption in a single excitation period and its control delay.Results show that the absolute values of dynamic stiffness,dynamic damping and energy consumption increase with the increase of control current.When the control current rises from 0 A to 10 A,the time span for the damping force switching into another stable value is about 500 ms.Based on the phenomenon that the dynamic stiffness of the damper is shown as negative,employing complex stiffness method,a linear model is established to analyze the mechanism of such problem.Simulation results can be concluded that dynamic stiffness or even dynamic damping will be negative under improper model parameters.Structural characteristics of the semi-active eddy current inertial damper are analyzed,and its nonlinear dynamic model is established,and the undetermined parameters in the model are identified by the NSGA-II genetic algorithm.Comparing the time-domain simulation results and dynamic characteristics of the identified model,the established model fits well with the test results in time-domain force curve and dynamic characteristics.As a result,the established model is capable to describe the dynamic behavior of the studied damper accurately to a certain extent.Vehicle models with ideal semi-active suspension and semi-active inertial suspension are established,and the simulation is carried out under various working conditions.The dynamic performance indexes and optimal parameters matching under various working conditions are obtained.In order to further verify the improvement effect of semi-active eddy current inertial damper on the vertical dynamic performance of the vehicle,a semiactive control rolling test is carried out on the semi-vehicle rolling test rig.The test results show that under certain working conditions considered in the test,compared with passive suspension,the on-off and continuous semi-active control methods can effectively improve the riding stability of the vehicle.