UniTire Model and Vehicle Stability Analysis Considering Parameter Uncertainty

Under extreme conditions, the impact of tire mechanics and friction characteristics on vehicle stability is very important. However, the road conditions and the tire parameters in actual driving are random which importantly affects vehicle dynamics, especially the stability of vehicle under the extreme critical state. Analyzing the test data of a large number of rubber friction test bench and high-speed tire test bench, it is found that the uncertainty of tire stiffness and friction coefficient can be mathematically described by the random characteristics of uniform distribution and normal distribution, respectively. On this basis, a UniTire stochastic model considering parameter uncertainty is established with the help of general polynomial chaos(gPC). The model can describe the tire mechanics response under the influence of uncertainty to provide a more accurate prediction of the mechanics characteristics. In order to verify the impact of uncertainty on the vehicle handling stability, the UniTire random model was embedded in the fourteen-degree-of-freedom vehicle model, and the steering wheel step and sinusoidal conditions under extreme conditions were selected for simulation analysis. The results show that under extreme conditions, the uncertainty of tire state parameters will cause the randomness of tire adhesion within a certain range, and affect the vehicle stability under the critical state. The research results can provide a theoretical basis for vehicle stability research under extreme conditions. © 2022 Editorial Office of Chinese Journal of Mechanical Engineering. All rights reserved.