Song Chuanxue

Improvement of Active Yaw Moment Control Based on Electric-Wheel Vehicle ESC Test Platform

In order to enhance the timeliness and accuracy of active yaw moment control for electric-wheel vehicle, an improved AYC system was designed. The control logic of the improved AYC system was based on identification of road adhesion coefficient. The control logic threshold value included three ranges. The controller of the improved AYC system adopted an integral separation PID controller in order to eliminate integral accumulation of control system. The controller was given different proportional coefficient, integral and differential coefficient according to different logic range. Two degree of freedom vehicle model was introduced to calculate the ideal value of yaw velocity and side-slip angle. An electric-wheel vehicle test platform was built based on XPC Target. Finally, the experiments were made based on the electric-wheel vehicle test platform. The experiments include a high adhesion road AYC experiment and a low adhesion road AYC experiment. The experimental results shown the improved active yaw moment control system could reduce the error of the ideal value and the actual value. The improved AYC systems overshoot and the shock were smaller.

Research on Key State Parameters Estimation of Electric Vehicle ESP Based on Multi-sensor

In order to enhance the estimation accuracy and improve the response time of the estimator for the key state parameters estimation of electric vehicle ESP system. A vehicle state estimator was built based on multi-sensor and the improved estimation algorithm. The estimator was used to estimate vehicle speed. A speed estimation model was introduced. The model was made up of three degree of freedom vehicle model, tire force calculation model and road adhesion coefficient calculation model. The mathematical equations of those models were introduced. The improved estimation algorithm was based on two times sigma points sampling of improved UKF. The estimation process was introduced including initialization, forecast and update. The state space equations of electric vehicle were established in accordance with the requirements of speed estimation. A simulation model was built based on Carsim and Simulink software. Combined simulation experiments were made including the speed of 55 kilometers and 95 kilometers per hour simulation experiment. The experimental results shown that the estimated speed could follow the actual speed timely and accurately. The improved estimation method was fit for ESP of electric vehicle.