Dynamic simplex algorithm-based optimal observer for vehicle state

In order to accurately monitor the key vehicle state parameters in real time, such as vehicle sideslip angle and road adhesion coefficient, and ensure the control effect and precision of Electronic Stability Control System (ESC), nonlinear Dugoff tire model which can be described by obvious expression and calculated on-line easily was introduced, and the nonlinear adhesion characteristics between tire and road were described. Dugoff tire model was modified to improve tire model accuracy under the huge slip ratio condition. The optimal observer for vehicle state applied by the combined dynamic simplex algorithm was proposed based on 2-DOF vehicle model and nonlinear tire model. The optimal observer was designed and tested online on the veDYNA software-based driver-in-the-loop simulation platform. The results show that the optimal observer for the vehicle state with combined dynamic simplex algorithm has better observation accuracy and quicker convergence speed.