关键词: 三编组铰接客车；多轮转向；转角比例系数；横向稳定性；轨迹跟踪性能；NSGA-II

Abstract: To enhance the single line shifting performance of three-car articulated buses, this paper analyzes optimal turning angle relationships under varying speeds using automotive dynamics and multi-objective optimization algorithms. First, a dynamic model is established with Adams/Car based on vehicle structural parameters. An optimization platform integrating Adams/Car and MATLAB is developed in ISIGHT software, with lateral stability and trajectory tracking performance as objectives and each axle's turning angle ratio coefficients as variables. The secondgeneration non-dominated sorting genetic algorithm (NSGA-II) is applied to determine optimal turning angle ratios in the medium-high speed range (40～70 km/h), with coefficient switching for non-optimized speeds achieved through a digital table. Results demonstrate that during mediumhigh speed shifting: the lead car's two axles rotate in the same direction with coefficients increasing with speed, the middle car's two axles rotate in opposite directions, and the tail car's rear axle rotates opposite to the lead car's front axle. After optimization, target values for all speeds are significantly reduced, with the lateral trajectory deviation decreasing by 82.46% at 70 km/h. Target values for non-optimized speeds are also effectively improved through digital table interpolation. In summary, the optimized axle turning angle ratios under single-line shifting conditions effectively enhance the bus's lateral stability and trajectory tracking performance.

Key words: three-car articulated bus; multi-wheel steering; steering angle ratio coefficient; lateral stability; trajectory tracking performance; NSGA-II