Active Control Of Vehicle System Hunting Motion

Recent years,the high-speed EMU has been developed rapidly in China.However,in the process of long-term service,the high-speed EMUs might appear some inevitable dynamic problems.These problems will affect the passenger comfort and even imperil the operating safety.Among the dynamic problems,the three typical phenomena are the car-body sway,bogie hunting alarm and car-body abnormal shaking.Aiming at these three phenomena,the following research work is carried out in this thesis:(1)The phenomena of car-body sway,bogie hunting alarm and car-body shaking appeared in the long-term track test are investigated.Then the nonlinear dynamic model of vehicle system is established with considering the rigid car-body and flexible car-body.The dynamic model is validated through comparing the experimental modal and simulating modal results.Furthermore,the electromechanical actuator mounted on the primary suspension guiding arm is introduced.(2)According to the tracking test data,the mechanism of car-body primary hunting instability is analyzed.The car-body hunting is identified by using reasonable method.Through constructing the deviation signal e(t)and the active control strategy is suggested.The results show that the car-body sway can be depressed effectively using active control.(3)The mechanism of bogie instability according to the tracking test data is studied.The Identification method of the bogie instability is proposed.Through constructing the deviation signal e(t),and the active control strategy is given.The results show that the bogie instability can be depressed effectively using active control.(4)The mechanism of car-body shaking according to the tracking test data is researched.The evaluation method of the car-body abnormal shaking is introduced.Through constructing the deviation signal e(t),the active control strategy is proposed.The results show that car-body abnormal shaking can be depressed effectively using active control;...