基于RSM的立柱加强板定位布局多目标优化

Multi-objective optimization of locators layout of reinforced panel based on RSM

为了提高汽车B柱装配质量,选取立柱加强板零件为对象,以零件上各定位块的坐标为优化变量,以侧围外板与立柱加强板的装配间隙为优化目标,基于响应面法(response surface methodology,RSM)与尺寸控制系统(3DCS)三维公差分析软件,建立两者之间的二阶响应面模型,通过响应曲面图和等高线图分析各变量之间的交互影响规律,并借助于Design-expert软件对目标函数进行优化,得到各定位块最佳的坐标组合,即定位块L1的X方向坐标值为1 360mm,L2的X方向坐标值为1 538mm,L3的Z方向坐标值为241mm,L4的Z方向坐标值为250mm.结果表明:与原始装配结果相比,3个检测点的装配间隙分别减小了41.5%、31.8%、39.7%,并达到了超差率要求,有效地解决了B柱传统装配中过程极易出现的间隙过大的问题,生产实践结果进一步验证了该方法的可行性,同时极大地提高B柱的装配效率.

The reinforced panel was chosen as the object in order to improve the assembly quality of automobile B-pillar,The coordinate values of locator blocks on reinforced panel were taken as optimization variables.The assembly gap between auto body outer panel and reinforced panel was taken as optimization objective.The quadratic response surface models were constructed based on response surface methodology(RSM)and tolerance analysis software three dimensional control system(3DCS).The mutual influence among these different coordinates were analyzed through 3Dresponse surfaces and the 2Dcontour plots.The multi-objective function was optimized by Design-Expert software.The best combination of coordinate values of locator blocks were obtained,i.e.L1x=1 360 mm,L2x=1 538 mm,L3z=241 mm,L4z=250mm.Results show that the assembly gaps(d0,d1 and d2)were decreased by 41.5%,31.8% and 39.7%respectively compared with the initial assembly results.The superb rate was markedly reduced,which effectively solved the problem of excessive gap in the traditional assembly process of B pillar.The production practice further proves the feasibility of the method,which can greatly improve the assembly efficiency.