Modeling And Control Of High-speed Train Lateral Semi-Active Suspension System With Magnetorheological Damper

With the continuous expansion of railway construction scale and the improvement of train speed,there are a lot of challenges in terms of smooth running and passenger comfort.One of the most effective ways to improve the running quality of high-speed train is to use suspension system to attenuate the lateral vibration.Compared to passive suspension system and active suspension system,semi-active suspension system has a comprehensive performance.Therefore,it is of great practical significance to study the dynamics model of vehicle system,the control algorithm to suppress vibration and the adjustable shock absorber for improving the smoothness and comfort of high-speed train.Firstly,this paper introduces the current research of train suspension system,analyzes the advantages and disadvantages of three kinds of suspension control systems(passive suspension,active suspension and semi-active suspension),and emphasizes the research progress of semi-active suspension control with magnetorheological technology and the characteristics of several kinds of semi-active suspension control methods which are widely used.Secondly,the characteristics and model of Magnetorheological Damper(MRD)are discussed in detail,and the Bouc-Wen model is used to improve it.A new semi-active suspension model of high-speed train with magnetorheological damper was proposed based on the three-degree-of-freedom model of the train.In order to further illustrate the difference between the proposed model and the original one in terms of refined modeling,simulation experiments are carried out.Then,a nonsingular terminal sliding mode(NTSM)strategy is proposed for the threedegree-of-freedom half-car model of the train,which improves the running stability of the vehicle by controlling the damping force.In the simulation part,the hybrid damping control method based on the skyhook and groundhook and the passive suspension control method are introduced to compare with the NTSM strategy proposed in this paper.It is verified that the semi-active suspension control method based on NTSM has significant oscillation damping capability for both the train body and the train bogie.Finally,in order to effectively handle the current-driven nonlinear model and maintain strong robustness while eliminating control chattering,a new current control method based on the semi-active suspension model of high-speed train with magnetorheological damper is introduced to control the signal of magnetorheological damper instead of indirect force,so as to suppress the lateral train vibration.The second-order sliding mode(SOSM)variable structure control strategy is used to control the change rate of the current.The suspension system with magnetorheological damping based on SOSM,resonance control based on internal mode suspension system and passive suspension system are compared and tested,and the RMS value and the Sperling stability index are used to further quantitatively analyze the vibration reduction effect of the designed controller.The experimental results show that the second-order sliding mode control can effectively improve train running stability and quality.