动力总成悬置系统的稳健设计

Robust design of powertrain mounting system

针对悬置刚度的不确定性对系统性能的影响,采用稳健设计理论对动力总成悬置系统进行优化设计,并在设计过程中引入全局优化算法和并行计算技术以提高计算效率。建立系统在曲轴坐标系、扭矩轴坐标系及车辆坐标系下的运动方程,并针对系统受到的各项激励分别提出模态规划方案。制定了首先应用全局优化算法搜索可行域,然后拆分可行域并应用并行计算技术执行稳健评价的设计流程。以某动力总成悬置系统为例,建立了稳健优化模型并按照设计流程计算求解。优化结果显示:稳健设计方案模态解耦率的平均值相对确定设计方案变化不大,但是标准差却有明显减小,尤其是当设计变量的不确定水平较大时,系统的稳健性有显著改善。

Robust design of powertrain mounting system is researched to improve the robustness of the system under uncertain stiffness property of the mount.Global optimization algorithm and parallel computation technique are employed to improve the computational efficiency.The motion equations of the system are built in crankshaft axis system,torque roll axis system and vehicle axis system.Modal formulation is presented for each excitation in a specific axis system.A design procedure is proposed.In this procedure global optimization algorithm is employed to search feasible region first;then the feasible region is divided and distributed into each computation core;finally,parallel computation technique is used to carry out robust evaluation.A robust optimization model is formulated based on a powertrain mounting system and optimization is carried out according to the proposed design procedure.Results indicate that the robust mean value of decoupling ratio has a little variation from the deterministic one,but the robust standard deviation is obviously smaller than the deterministic one.Especially for higher uncertain level,the robustness of the system is significantly improved.