Vehicle Stability Control Research On Active Front Steering

Steering system is the vital device for controlling control the car route and direction. Its p erformance directly affects the vehicle handling and stability performance. Active Front-whee l steering system has variable ratio and active vehicle stability control advantage and make the vehicle get ideal steering characteristics, and the ideal of the so as to meet the people’s car to t urn the low speed maneuverability and high-speed, stability of security requirements, satisfyin g people for automotive steering flexible maneuverability at low speed and stability security r equirements at high-speed.The control system is the core of active front wheel steering system. The quality of contr ol strategy directly affects active front wheel steering performance. First of all, this paper esta blished the vehicle dynamics model, tire model and active front wheel steering system mathe matical model, and carried on the simulation analysis and verification of the model, providing correct car model for the research of the vehicle stability. Secondly, the basic principle of veh icle stability control was analyzed theoretically and a controller was designed with yaw angul ar velocity as the control variables. Then the PID control parameters were adjusted using gene tic algorithm. For the limitation of PID control, an active front wheel steering control system was proposed based on sliding-mode control.Due to the "chattering" phenomenon of the slidin g mode control, the proposed neural network adaptive sliding mode control strategy can keep the system parameter variations and external disturbance strong robustness, effectively weake n the system chattering and improve the response speed and tracking accuracy, achieving high comprehensive control performance.Research results show that the designed active front wheel steering control system can co ntrol the vehicle more easily and don’t have to give compensation toward uncertainty and exte rnal disturbance. It can improve the vehicle stability and comfort without affecting the driver control purpose.