Research On Parameter Estimation Method Of Vehicle State For ESP

ESP（Electronic Stability Program) based on the ABS（Antilock Brake System）and TCS(Traction Control System)Greatly improves the active safety of vehicle. ESPis becoming an international hot spot of automobile active safety research，and hasbeen equipped in many high-end cars, It not only integrates all the functions of ABSand TCS, Avoid the car from dangerous situations such as the over-steering andunder-steering，but can improve the stability of the vehicle under extreme drivingsituation.The ESP control process is based on the accuracy of state parameters，which isvery important for Vehicle Stability, However, these parameters are accuratelyobtained with greater difficulty, Some parameters can be obtained by correspondingsensor, but the restrictions the technical conditions such as Machining process andmanufacturing cost make some sensors (such as gyroscopes) difficult to spread, thatleads to some important parameters difficult to obtain directly, and makes the controlof ESP difficult. Thus, how to accurately obtain the status parameters of the car inmotion is an important part of the ESP research process. Automotive wheel speed,angle and other information can be obtained directly from the relevant sensorcurrently, but state parameters which have a significant impact on the stability of thecar such as sideslip angle are difficult to obtain directly through the sensors. Therefore,the method that indirect access the parameters is needed to solve the problem.With the deepening of research，Researchers around the world put forward manymethods to estimate the parameters of motorsport, the soft measurement method is therepresentative method, it can estimate the parameters for motor sport through vehicledynamics model and equation of state-based software algorithms and replace thedirect measurement of physical sensors. The same method is used in the paper, vehicle yaw rate and sideslip angle are estimated using kalman filter algorithm whichis the classic method of soft measurement methods based on automobile model of twodegrees of freedom which is widely used in vehicle dynamics research. The paper alsoestablishes a vehicle simulation model, the design of ESP controller module in themodel is based on fuzzy control theory, a comparison is made between the estimationresults and simulation results of vehicle yaw rate and sideslip angle to verify theeffectiveness of classic kalman filter algorithm.