基于6σ方法的动力总成悬置系统稳健性优化设计

Robustness optimization of powertrain mounting system based on 6σmethod

为提高动力总成悬置系统的隔振性能及其优化设计的稳健性,首先建立悬置系统6自由度模型,以各自由度方向的解耦率最大及传递到车身侧的动反力最小为目标,以各悬置点三向刚度为设计变量,选用遗传算法、DOE技术对悬置系统进行初步优化与敏感性分析以获得目标值较好的群体;然后应用6σ方法进行一次或多次稳健优化,获得较为理想的优化解;最后应用蒙特卡罗模拟技术进行稳健分析。结果表明,该方法在保证刚度合理分布及动反力最小的基础上,能有效提高悬置系统各自由度方向上的解耦率,增强悬置系统的稳健性,同时还保证了NVH性能。

In order to improve the vibration isolation performance of the powertrain mounting system and the robustness of the optimization design,a 6 DOFs model of the mounting system is built.The maximum decoupling rate of each DOF direction and the minimum dynamic reaction force transmitted to the vehicle body are taken as the objectives,and the three-direction stiffness of each mounting point is taken as the design variable.Genetic algorithm and DOE technology are used to conduct preliminary optimization and sensitivity analysis of the mounting system to obtain the population with better target value.Then,the 6σmethod is used to perform one or more robust optimization,and a relatively ideal optimal solution is obtained.Finally,the Monte Carlo method is used to analyze robustness.The results show that,on the basis of ensuring reasonable stiffness distribution and minimum dynamic reaction force,this method can effectively improve the decoupling rate in each DOF direction of the mounting system,enhance the robustness of the mounting system,and also ensure NVH performance.