城轨列车反推自动停车控制算法

Backstepping Automatic Stop Control of Urban Rail Vehicles

为了实现城轨列车自动停车功能,根据电空制动系统的工作原理及其动态特性,建立了具有输入时滞的非线性城轨列车制动模型,克服了传统模型中制动减速度难以测量的缺点。针对模型中的输入时滞以及非线性特性,设计了一种基于Krasovskii泛函算子的反推自动停车控制器,以消除制动过程中闸瓦摩擦系数和制动系统时滞造成的影响。算法的主要改进在于:基于预测的思想以及反推技术,将误差信号表示为2个与延时相关的Krasovskii泛函算子,并且其中一个泛函算子为指数收敛的。基于Lyapunov-Krasovskii稳定性定理,证明了闭环列控系统的稳定性和收敛性。为验证自动停车控制器的正确性,利用Matlab仿真软件对城轨列车制动系统进行了数值仿真,结果表明,所提算法不仅可以获得较高的停车精度,并且保证了城轨列车运行的平稳性。

To realize the function of automatic stop control of the urban rail vehicle,a nonlinear brake model with input delay is built based on the operational principle and dynamics of the electro-pneumatic brake system.This model overcomes the shortcoming that actual brake deceleration is almost unmeasurable in conventional model.To deal with the nonlinearity and input delay in the model,a new backstepping stop controller based on Krasovskii functional operators is proposed.During the brake process,the presented controller can eliminate the effects due to brake shoe friction coefficient and brake system delay.With the prediction scheme and backstepping technique,the main improvement of this algorithm is that the error signal is expressed by two Krasovskii functional operators,one of which is exponentially stable.Based on Lyapunov-Krasovskii theorem,the stability and convergent behavior of the closed-loop train control system are proved.To confirm the correctness of the proposed automatic stop controller,the brake system is simulated by Matlab tools.Simulation results illustrate that this method can obtain high stop accuracy,and guarantee the operational stability of the urban rail vehicle.