Research On Vehicle Stability Modeling And Control Strategy Based On Yaw And Roll

Vehicle stability control issue has become one of the priorities of modern automotiveengineering field of active safety. Electronic Stability Program (ESP) is by far the mostadvanced automotive active safety control system, which can significantly reduce vehiclesideslip or rollover accidents. Based on vehicle ESP system as the research object, thispaper researched on integrated control issue of vehicle yaw and roll stability to enhancerollover control function of vehicle ESP system, further improving automotive activesafety.This dissertation firstly analysed the vehicle suspension roll characteristics andvehicle lateral model, combined with tire dynamics model, an8DOFs vehicle modelincluding yaw and roll motion was established. Combined with the traditional vehicleESP direct yaw control strategy, the yaw rate feedback fuzzy controller for yaw stabilitycontrol was established to achieve the yawing stability control. Then an intergratedcontrol strategy with emergency roll control has been introduced. Using traditional sensorsignal static threshold control method, the roll coefficient is calculated by using vehiclelateral acceleration which is provided by the vehicle ESP sensor, and the emergency rollcontrol will be activated if the roll coefficient exceeds some predetermined referencevalue. Through applying emergency brake force to the vehicle front wheel to timelyadjust the lateral acceleration, the effective control of vehicle rollover is achieved, finallyrealized the vehicle yaw and roll dynamics stability control. Intergrated control system isdivided into uper and lower two layers controller, the uper controller takes vehicle’s yawand roll dynamics stability as the control target, and then through implement of the lowercontroller to output the target wheel cylinder pressure. The effectiveness of model andcontrol system was preliminarily validated through the analysis of off-line simulationunder typical conditions.Based on dSPACE hardware-in-the-loop simulation test bench, the real-timesimulation test of various typical conditions was further performed, using physicalhardware instead of the hydraulic braking system. The results indicated that the real-timesimulation result is basically the same as the off-line simulation result. The effectiveness and real-time of intergrated control strategy was verified on vehicle yaw and roll stabilitycontrol.