Objective During the operation of straddle monorail vehicles, excessive or violently fluctuating lateral forces on the guide wheels are prone to cause shoulder cracking or scraping of the guide tires, posing risks to train operational safety. To improve the lateral stress state of vehicle guide wheels, it is necessary to conduct research on suspension parameter optimization based on the lateral force control of straddle monorail vehicle guide wheels.

Method Based on the UA （University of Arizona） tire model, a straddle monorail vehicle dynamics model is established. The Sobol global sensitivity method is employed to conduct a sensitivity analysis on the suspension parameters of the monorail vehicle, screening out the vehicle suspension parameters that significantly affect the lateral force of the guide wheels. Based on the ModeFRONTER multidisciplinary optimization platform, taking the dynamics parameters that significantly affect the lateral force of the guide wheels as optimization variables, and selecting the mean value and root mean square （RMS） value of the lateral force of the guide wheels as the optimization objectives, while simultaneously using indicators such as the maximum radial force of the guide wheels and the rate of wheel load reduction of the running wheels as constraint conditions, a co-simulation optimization model is constructed to complete parameter optimization. Furthermore, simulation verification is carried out on the optimal scheme.

Result & Conclusion  The optimized mean value and RMS values of the lateral force of the guide wheels decrease by 27.78% and 32.29%, respectively, compared to those before optimization. This proves that the method of optimizing vehicle suspension parameters can mitigate the problems of excessive and violently fluctuating lateral forces on the guide wheels, effectively resolving the resulting issues of tire shoulder cracking or tire stripping.