Research And Validation On Control Strategy Of Vehicle Electronic Stability Control System

The Electronic Stability Control system can effectively improve the active safety performance of the vehicle.It determines the current vehicle stability state by monitoring the sensor signal.When the vehicle is in a state of instability,the system actively adjusts part of the wheel cylinder pressure to ensure the stability of the vehicle.The research of ESC control algorithm is the core and key of the system.Due to the late start of our country,the related technology research is still weak.Research on the control strategy of ESC system has a great significance to the development of China's automobile industry.Firstly,this paper analyzed the basic principle of ESC system.In order to solve the problem that the vehicle slip angle and the road adhesion coefficient of ESC system are difficult to measure,we used the method combining existing sensor signal and vehicle dynamics model to estimate parameters.The estimation of vehicle slip angle is transformed into the estimation of longitudinal vehicle speed and lateral vehicle speed.This paper used steady-state Kalman filter and extended Kalman filter to estimate longitudinal vehicle speed and lateral vehicle speed respectively,thereby calculated the vehicle slip angle value.The road adhesion coefficient estimation algorithm is designed based on combining the tire dynamics model and the - curve.The co-simulation platform is used to simulate the parameter estimation algorithm,and the simulation results show that the estimation method proposed in this paper meets the real-time and accuracy requirements of the ESC system.The core control strategy of the ESC system is designed,yaw rate and vehicle slip angle are determined as the joint control variables of the ESC control strategy by analyzing the stability of the vehicle running state.Design the overall structure of the ESC control algorithm based on the modular idea.Correcting the tire lateral stiffness of the vehicle dynamics model by using the least squares method including the forgetting factor,then determining the expected values of yaw rate and vehicle slip angle.Design the joint fuzzy PID controller based on yaw rate and vehicle slip angle,and then determining the joint control proportional coefficient according to the value of road adhesion coefficient and vehicle slip angle by using the fuzzy control method.On this basis,in order to solve the problem that realizing of the control algorithm the brake execution part algorithm is designed to convert the additional yaw moment value into the actual controllable wheel cylinder pressure.The co-simulation model of Car Sim-Simulink was built and the co-simulation test of corner sinus input condition was tested to verify the feasibility of the ESC control strategy.In order to further verify the effectiveness and reliability of the control strategy,we build a HIL test bench for ESC control strategy hardware-in-the-loop testing.The test conditions of single line change,double line change,steering wheel angle step and snake-shaped pile under high and low road adhesion were tested.The test results further prove that the ESC control strategy designed in this paper is effective and feasible.