Virtual Modeling And Controllability And Stability Test Simulation For Four-wheel Steering Automobiles

Four-wheel steering (4WS) for vehicle is one of the most important methods to improve lateral dynamic performance of the vehicle;This paper concerns the handling stability performances with some control strategy based on a 4WS virtual vehicle simulation model;Some theoretical and simulation results are drawn out as follows:1)According to road vehicle test ISO standard:ISO/DIS 4138-2003,ISO/DIS 7401-2000 and ISO 3888-1999, performs an front wheel steering vehicle handling stability performances, and processes test data and plot the results.2)One virtual dynamic parameterized model of 4WS vehicle is made in this paper by using software-ADAMS/Car. The model consist of vehicle body, tire, suspension systems,steering system and dynamic parameters and so on. The virtual model based on a real vehicle's structure and dynamic parameters, and performs a front wheel steering simulation then compared with the road test results.3)By using partial decoupling and individual channel design method, decouple the control of sideslip from the control of yaw rate, establishes a controller in MSC.EASY5 for 4WS vehicle, and implements rear steering angle control under high speed.4)According to road vehicle ISO test standard, studies transient state and steady state response characteristics with a front-wheel steering angle and corresponding 4-wheel steering control method. Including yaw velocity and lateral acceleration response characteristics and other kinetics indexes.Results indicate:By using partial decoupling and individual channel design, with suitable inputs of the front and rear steering angle numerical value, ratio control, orientation and steering TD, will greatly influence the lateral dynamics performance of the 4WS vehicle.