Study on improvement of LuGre dynamical model and its application in vehicle handling dynamics

The accurate description of contact characteristics between tire and road surface may significantly affect the vehicle motion simulation and control analysis. Based on the LuGre tire model, the pressure distribution function of loading is modified as a non-uniform distribution pattern through new method of recursion formula. The mathematical expression of modified LuGre tire model is achieved through introducing the Bouc-Wen model to reflect tire hysteresis behavior, which takes into consideration the process of dynamic effect of tire vertical loading and tire footprint length. The effectiveness of model is verified through comparison with classic magic formula (MF) and LuGre tire model. Furthermore, the stability of solution for the modified LuGre tire model in the prediction of tire force and alignment torque is demonstrated in frequency domain. Finally, a nonlinear four-DOF vehicle handling dynamics model is built. The front wheel steering angle and the rotational angular velocities of the six tire from a calibrated virtual vehicle is entered into the vehicle model system with modified LuGre tire model as input data. The responses of longitudinal velocity, lateral velocity, yaw rate and roll angle are obtained under two kinds of limit conditions. The comparison results demonstrate the correctness and effectiveness of the built model, which further prove that the modified LuGre tire model is applicable for handling performance analysis of vehicle system.