Research On Cruising Control For CRH Electric Multiple Unit Under Event Trigger

In the high-speed train system,the automatic train control system(ATC)is the core system that ensures the safe operation of trains and improves operational efficiency.Auto drive system(ATO)of ATC system is the future development direction of high-speed trains.In the actual operation process,high-speed trains have different operating conditions and changing environments,and the core problem that ATO needs to solve is to automatically adjust the traction and braking force according to these changing conditions,so that high-speed trains can operate stably and arrive on time,and achieve the goal of improving passenger comfort and reducing energy consumption based on certain standards.Cruise mode is a commonly used operation mode for high-speed trains throughout the entire train operation process.In this mode,it is convenient and fast to control the train to track the given expected speed trajectory,and to maintain appropriate distances between train carriages and between trains.While high-speed trains operate steadily on time,they also have great safety.This paper aims to keep up with the development of autonomous driving technology,and explore it on the basis of previous research on cruise control.Under the cruise control strategy,CRH EMUs can not only cope with more complex and varied and harsh operating conditions,but also ensure that the Electric Multiple Unit(EMU)can track the expected speed,keep the relative spring displacement within a reasonable range,and run in an ideal state.It can also have H∞ stability and exponential stability under the premise of reducing the communication frequency.Firstly,the longitudinal dynamics model of CRH EMU is established.Accurate model is the basis of cruise control research.In the past,CRH EMU models mostly have two forms,one is simple point model and the other is multi-point model.The elementary point model often neglects the stress relationship between the cars and regards the EMU containing multiple cars as a whole,which can’t accurately describe the stress situation of the train,resulting in inaccurate train control.Most of the existing researches put forward the multi-particle model of the train,which fully considers the influence of various forces in the actual running process of the train,and puts forward the control strategy based on the accurate model to reduce the control error.Considering the influence of flexible coupler and basic resistance(rolling mechanical resistance + aerodynamic resistance),the longitudinal loading multi-body model of train is established.There are many uncertainties in train operation,such as wind gust,disturbance caused by track irregularity,and time-varying delay caused by flexible coupler hook slow.Based on the above factors,the multi-body model is fully considered and supplemented,and a time-delay EMU system with disturbance is established.Secondly,a cruise control strategy based on Lyapunov stability theory and linear matrix inequality(LMI)is proposed.In the process of network information transmission,due to the limited network bandwidth,communication redundancy,packet loss,communication congestion and other phenomena will inevitably occur.Based on the above,the event triggering mechanism is introduced.Select the appropriate event triggering conditions,design the state feedback control rate,and propose the event-triggered H∞ cruise control.The superiority of the event triggering mechanism and the cruise control strategy under the event triggering is verified by simulation.Then,based on the discussion in the previous chapter,an exponential term is introduced to construct an exponential LKF,and a cruise controller with an exponential is designed to ensure that the system can converge according to the predetermined convergence rate,and can track the expected speed and the safe compartment distance.The exponential stability criterion is derived by deducing the asymptotic stability criterion of the closed-loop system.The stability problem of the system is transformed into a feasible solution for solving linear matrix inequalities,and the event triggering mechanism and dynamic event triggering mechanism are introduced respectively in the derivation process,and the stability criterion with event triggering condition is obtained.Finally,the effectiveness of the exponential cruise control algorithm proposed in this chapter is verified through simulation experiments.The trigger effect and comparison between the static event trigger mechanism and the dynamic event trigger mechanism are verified through the comparison of trigger interval graphs,and the validity of the proposed theorem is proved.Finally,a state feedback control rate with short input delay is designed,and a cruise control method with double time-varying delay is proposed by sampling data.The LyapunovKrasovskii function(LKF)with delay parameters is constructed,and the delay information is fully introduced.In view of the disturbance effect,sufficient conditions are given to suppress the disturbance,and the H∞ cruise control method is proposed to control the speed fluctuation and displacement of the train rapidly converging to the steady state.The EMU at equilibrium tracks the desired speed and ensures a stable relative displacement error and reaches the specified H∞ interference attenuation level to ensure safe and comfortable operation.The effect of time-varying delay and disturbance on train stationarity is verified by two numerical simulations,and the superiority of the proposed method is proved.