Simulation Analysis On Passability Of Multiple Articulated Vehicle With Full-axle Steering

With the rapid development of urbanization in China,the traffic pressure is increasing year by year.The urban rail transit system with high efficiency,punctuality,safety and comfort,energy saving and noise reduction has become the main force of urban transportation.The new urban rail transit with less investment,short construction period,and strong environmental adaptability has become the best choice to solve the traffic pressure of small and mediumsized cities.As a new type of urban rail transit system,the electronic guided system with rubber tire has excellent trafficability and steering performance.With the support of advanced virtual track following control technology,its development prospect can’t be underestimated.Full-axis steering technology can effectively improve the trajectory following performance of the vehicle.This paper aims to reduce the width of the vehicle channel,reduce the trajectory deviation,and improve the trafficability and steering flexibility of the vehicle.This paper focuses on the research of the full-axis steering control strategy and optimization of multiple articulated vehicles.First,building a mathematical model of the vehicle and studying the full-axis steering control strategy with the goal of trajectory following.It analyzes the longitudinal kinematics characteristics of multiple articulated vehicles,and reduces it to a bicycle kinematics model according to the structural characteristics of the vehicle.The vehicle is modularized.The rigid module and the flexible module are used as the research objects to study the rear axle steering law of different modules to follow the trajectory,and the first-order delay steering control strategy is obtained.Secondly,in order to further improve the accuracy of trajectory following,an optimization study was carried out on the value law of the first-order delay variable parameter.After comparing the two optimization schemes,this article finally chosen to follow the optimal scheme for analysis.The influence of vehicle operation parameters,vehicle structure parameters and road condition parameters on the optimal parameters was discussed.The results show that the optimal value of the first-order delay variable parameter is linearly related to the speed of the first axle,has nothing to do with the angle of the first axle,and has a quadratic function relationship with the wheelbase of the vehicle.Then,through co-simulation,the practicability and effectiveness of the first-order delay steering control strategy are further verified.Combined with the vehicle structure characteristics and simulation verification objectives,the vehicle multi-body dynamics model is built.According to the first-order delay steering equation and its derivation,the Simulink control model is constructed.Taking the articulated semi-trailer vehicle as an example,the feasibility and effectiveness of the first-order delay steering control strategy are further verified.Finally,taking the ART by CRRC Zhuzhou Institute Co.,Ltd.as an example,the influence of the first-order delay steering control strategy on the trafficability and steering performance of ART is studied.Compared with the front axle steering vehicle,the results show that the full-axle ART based on the first-order delay steering control strategy has obvious improvement in the following performance,channel width,steering flexibility and passability.