高速列车主动横向悬挂系统的临界时滞分析

Analysis of critical time delay in active lateral suspension systems for high-speed trains

在高速列车主动悬挂系统动作的过程中,时滞现象在所难免,这在一定程度上制约了其性能的发挥。为了探究二系横向主动悬挂系统时滞现象对车辆动力学性能的影响,文章首先建立两自由度1/4车辆横向简化模型,推导出临界时滞理论计算公式;然后,建立高速列车全自由度动力学模型,在Simulink中搭建控制模块进行联合仿真,采用一阶低通滤波器模拟实际控制力的幅值衰减和相位滞后特性,研究模态天棚与PID等控制策略的时滞影响规律。仿真结果表明,随着时滞的增加,模态天棚控制策略下的车体振动迅速恶化,横向平稳性指标迅速增加至2.0以上,而PID半主动控制几乎不增加横向平稳性指标;2种控制策略在50 ms内的时滞基本不会使构架振动剧烈恶化。若采用平稳性指标作为临界时滞的判据,则除PID控制策略外的大多数策略对应的临界时滞随着车速的提高而降低。文章系统性地研究了时滞问题,对高速列车主动悬挂系统的设计和优化具有一定的指导意义。

In the actuation process of active suspension systems for high-speed trains,the phenomenon of time delay is inevitable,which to some extent restricts the performance of these systems.This paper aims to investigate the impact of time delay in secondary lateral active suspension systems on the dynamic performance of vehicles.Firstly,a simplified 1/4 vehicle lateral model with two degrees of freedom(DOF)was established,and the theoretical calculation formula for critical time delays was derived.Next,a full-DOF dynamics model of high-speed trains was developed,and a control module was built in Simulink for co-simulation.A first-order low-pass filter was subsequently used to simulate the amplitude attenuation and phase lag characteristics of actual control forces.Furthermore,the influence laws of various strategies on time delays were explored,including modal sky-hook and PID control methods.Simulation results show that as time delays increase,the modal sky-hook control strategy leads to rapid deterioration in carbody vibrations and a rapid rise in the lateral Sperling index beyond 2.0.In contrast,the PID semi-active control brings about minimal increases in the lateral Sperling index.Time delays within 50 ms under both strategies don’t cause severe deterioration in the vibrations of the bogie frames.When considering the Sperling index as the criterion for critical time delays,most control strategies other than PID control strategy resulted in decreased critical time delays with increasing train speeds.This paper presents a systematic investigation into the issue of time delays,offering guidance for the design and optimization of active suspension systems for high-speed trains.