设计空间差别处理优化方法及其在汽车轻量化设计中的应用

提出了一种设计空间差别处理方法，改进了传统的设计空间移除方法会移除全局最优的弱点。首先应用昂贵点构建一个逐渐缩小的重点空间，同时将在设计空间移除方法中被删除的空间定义为其他空间，然后每次迭代都应用二阶多项式响应面（QF）同时搜索这两类空间，并分别从中选取数目不同的新的昂贵点参与QF的更新和重建。该方法采用在其他空间中选择少量新的昂贵点来代替移除空间，有效地避免了局部最优的陷阱。多个标准函数算例的验证表明，新的方法具有较高的精度和效率。将该方法应用于某款车的后车架轻量化设计中，经过优化，后车架系统的质量减小了7.67kg，即整个系统质量减小了10.4%，且其刚度性能得到提高。与以前提出的混合自适应元模型方法相比，新方法的精度和效率都有显著提高。

Design Space Differentiation Optimization Method and Its Applications to Vehicle Lightweight Design

A meta-model based design space differentiation method (DSD) was proposed to improve the performance of traditional region elimination methods. In this method, a gradually reduced important region was constructed using the expensive points and the space to be removed in the region elimination methods was defined as the other regions and would also be searched. When the design spaces were divided, the quadratic function (QF) might be used in the search of the two subregions and several new expensive points would be selected for the updates of the QF meta-model both in the important regions and the other regions. Instead of region elimination, fewer new expensive points would be selected in the other regions, which might avoid the traps of the local minima. It is demonstrated by several benchmark functions, the newly proposed method shows its great performance. Then, the proposed method was applied in vehicle lightweight design problems. With the proposed method, the masses of the rear frame are reduced by 7.67kg, reaches the 10.4% of the systems, and its stiffness is also improved. When compared with previously developed hybrid and adaptive meta-modelling(HAM) method, both the search efficiency and accuracy are noticeably increased.