Research On The Simulation Of ESP-Vehicle Electronic Stability System

When the car steers on the high coefficient of friction of the road at high speed or on the low coefficient of friction of road surface, it is easy to reach the physical limitof adhesion between the tires and the road, and leads to accidents. ESP------thevehicle electronic stability program is working on the situation. It regulates the engine torque and the wheel brake pressures using traction control components to minimize the difference between the actual and the desired motion. So the car can be controlled by the driver at the emergency situation to keep the car running on safety.The paper builds a seven-degree-of-freedom yaw plane vehicle model based on the Pacejka's "magic formula" tire model. The vehicle model considers the longitudinal, lateral,yaw orientation and four wheels whirl, ignoring the others. We verified the optimization theory can be used in ESP to improve the stability of the car by the vehicle model. The vehicle side slip angle and the yaw rate are the control variables to be considered in the paper. The ESP minimizes the difference between the actual side slip angle , yaw rate and the normal side slip angel , normal yaw rate to make sure the good manoeuvrability. We simulated the system at MATLAB SIMULINC environment.From the simulation,we found the ESP system designed with optimization theory can guarantee the manoeuvrability. It can make the car running safely on high speed or low friction and make the driver drive the car normally.