Research On Four Wheel Drive Electric Vehicle Handling And Stability Control Method Based On Tire Nonlinear Characteristic

Handling and stability control is one of the key research directions in the field offour-wheel drive electric vehicles (4WDEV) high-speed driving safety. Based on the problemswhich are not easy to make vehicles follow drivers’ command and decrease the stability underextreme condition because of the nonlinear of tire lateral and longitudinal forces,four-wheel-drive electric vehicle handling and stability control principle and method based ontire nonlinear characteristic are researched.Firstly, the research situation and development tendency of the domestic and foreignfour-wheel-drive electric vehicle handling and stability control are introduced. Based onclassic "Brush Tire Model" and the assumption of flexible tread and rigid matrix, the tirenonlinear characteristics on the non-steady-state cornering is researched and nonlinear tiremathematical model is built. Based on four-wheel drive electric vehicle handling and stabilitycontrol principle, the relationship among the saturation characteristics of tire lateral force, thecoupling of tire longitudinal and lateral forces and four-wheel drive electric vehicle handlingand stability are analyzed. Then, fuzzy PID control method based on dynamic proportionaldistribution is proposed. Four-wheel-drive electric vehicle handling and stability fuzzy PIDcontroller are designed. In order to testify the proposed fuzzy PID control method based ondynamic proportional distribution, certain four-wheel-drive electric vehicle is taken asresearch object, a four-wheel-drive electric vehicle and its control simulation model is builtbased on vehicle system dynamic simulation software veDYNA and Matlab/Simulink,dynamic proportional distribution strategy and fuzzy PID control method are simulated andcompared on typical working condition. Besides, to testify the simulation analysis resultsfurthermore, four-wheel-drive electric vehicle handling and stability controllerhardware-in-loop experiment system based on veDYNA, LabVIEW and NI PXI is established.Fuzzy PID control method is verified through hardware-in-loop simulation.