Hunting Motion Control Of High Speed Vehicle Based On Magnetorheological Yaw Damper

Accompanied by the increase of the operating mileage of high-speed trains in our country,the vehicles are facing more and more hunting motion stability problems due to the contradiction between wheel-rail wear and suspension system parameters.There are two typical forms of hunting motions,one is primary hunting motion in which the carbody vibration is severe,the other is secondary hunting motion where the bogie vibration is severe.High-speed trains are usually equipped with yaw dampers,but the current passive suspension scheme cannot effectively solve the problem of vehicle motion stability in different operating conditions.Magnetorheological damper has the characteristics of continuously adjustable damping value.Therefore,this thesis proposes a high-speed train hunting motions control method based on magnetorheological yaw damper.The following research work is mainly carried out:(1)The working principle of the magnetorheological damper is analyzed.Based on the Sigmoid model,the Simulink software is used to build the magnetorheological yaw damper mechanical model.(2)The multi-body dynamics software UM is adopted to establish a non-linear dynamic model of a 50-degree-of-freedom vehicle system.The test data of vehicle hunting instability is analyzed,and the phenomenon of hunting instability is reproduced by through simulation.The UM/Simulink co-simulation control model is established.(3)The mechanism and evaluation method of the instability of the vehicle’s primary hunting motions are studied.The influence of the parameters of the yaw damper on the primary hunting motions is investigated.A semi-active control method of fuzzy control is used and thehe simulation results show that this method can suppress primary hunting motions of the carbody and the effect is obvious.(4)The mechanism and evaluation method of the instability of the vehicle’s secondary hunting motions are studied,and the influence of the parameters of the yaw damper on the secondary hunting motions is analyzed,and the continuous damping semi-active control method is proposed and compared with the fuzzy control method.It is verified by simulation that the two methods can effectively suppress the secondary hunting motions of the bogie,and the fuzzy control method is better than the continuous damping semi-active control method.