Running Stability for Monorail Vehicles Based on the Magic-Formula Tire Model

To enhance the applicability of monorail transportation for intercity transportation in large stations, straddle-type monorail vehicles need to use high-speed running wheels to increase speed. To ensure the dynamic performance of the monorail vehicle after increasing speed, it is necessary to carry out adaptation analysis of high-speed running wheels with secondary suspension system parameters. To improve the simulation accuracy of the running wheel under high-speed condition, a magic-formula tire model was adopted in this paper, the parameters of the magic-formula tire model were identified based on a genetic algorithm, and a spatial coupling dynamic model of a monorail vehicle was established based on the magic-formula tire model. Using the parameters of the secondary suspension system as optimization variables, the root mean square of the vehicle acceleration, and the wear factor of the running wheel, as the evaluation index, a study was conducted on the adaptation of the parameters of the secondary suspension system of monorail vehicle with high-speed running wheel. Based on the Pareto optimal solution set, the final optimization parameters of the secondary suspension system were obtained and the dynamic performance was verified. The research results show that through the optimization matching parameters between high-speed running wheel, air spring, and shock absorber in the secondary suspension system, the stability performance of the vehicle at the front left and rear right position is improved by 14.5% and 9.7%, respectively. The wear factor of the running wheel has decreased by 2.2% compared to before optimization, and the dynamic performance of the monorail vehicle in increased speed conditions meets the requirements.