基于6σ稳健性的电动汽车断开式转向梯形优化设计

Robustness optimization of divided steering linkage for electric vehicles based on 6σ design

建立了某电动轿车断开式转向梯形的数学解析模型并进行了相应的试验验证。以转向系实际内、外轮转角关系与理想阿克曼转角关系之差最小为优化目标,根据转向梯形运动特点推导出了约束条件,结合蒙特卡洛方法和6σ稳健性优化设计技术,分别对梯形底角、横拉杆长度、直拉杆长度及齿条长度进行确定性优化和稳健性优化设计分析与比较,分析了不稳定因素对优化结果的影响。结果表明:优化后的转向梯形更接近理想内、外轮转角关系;稳健性优化结果比确定性优化结果具有更高的稳健性和可靠性。

A mathematical model of divided steering linkage for electric vehicles is built and validated.Aiming at minimizing the difference between Ackerman steering angle and the practical steering angle,a robust optimization method is proposed based on theory and Monte Carlo simulation.The constraints are deduced by the characteristics of the steering linkage.The influences of uncertain factors on the optimization results are analyzed.The results demonstrate that the optimal linkage has a better Ackerman performance,and the robust design shows better reliability against the uncertain factors.