电动助力转向系统参数研究及优化设计

利用电动助力转向(Electric Power Steering,EPS)系统和二自由度整车的集成动力学模型,建立了汽车转向系统性能评价的转向路感、转向灵敏度和转向稳定性指标函数.通过频域仿真分析,研究了EPS系统结构与控制参数和转向性能指标之间的关系曲线.以转向路感和转向灵敏度有效频域能量均值为优化目标,转向稳定性为约束条件,建立了EPS系统多目标优化设计模型,并利用MATLAB遗传算法(Genetic Algorithm,GA)工具箱进行了优化设计.最后,对优化前后的系统进行了仿真对比分析.结果表明:EPS系统转向性能得到了较大提高,能够对EPS系统结构和控制参数进行匹配优化设计.

Parametric study and optimal design on electric power steering systems

With combination of the electric power steering （EPS） system and two degree-of-freedom integrated vehicle dynamical model,the index function is first established for steering feel,sensitivity and stability to assess the steering system performance.Through frequency domain simulation and analysis,the relational curve between the EPS structural and control parameters and the steering performance indices are then investigated.By using the steering feel and sensitivity as optimization objectives and steering stability as constraints,a multi-objective optimal design model for EPS system is next constructed using MATLAB genetic algorithm （GA） toolbox.Finally,a simulation comparison is conducted on pre-and postoptimization systems.To this end,the EPS system steering performance is significantly improved for matching optimization design on EPS system structural and control parameters.