公差稳健优化设计的研究

为了解决产品加工成本与质量稳健的协调性问题,提出了一种新的公差稳健优化设计数学模型.依据公差稳健设计的思想,考虑产品质量的模糊性,以封闭环误差分布概率密度函数的方差和优质品概率之比为设计目标,建立了公差优化设计产品质量稳健性损失成本目标函数,并研究了优质品率和封闭环误差分布方差的确定方法.以加工成本和产品质量稳健性损失成本为目标,以模糊装配可靠度、可取公差极限范围为约束条件,建立了公差多目标优化数学模型.举例说明了文中所述的公差稳健优化设计方法的应用,采用遗传算法实现了公差的多目标优化设计.实例表明,该方法能够协调零件的加工成本和产品质量的稳健性损失成本,使优化指标的综合性能最佳.

Tolerance-robustness optimization design

To solve coordination problem between manufacturing cost and quality robustness,a new mathematical model on tolerance optimization for quality robustness was proposed.Based on the idea of tolerance-robustness design,considering the fuzziness of product quality,and taking the ratio of the variance of probability density function of deviation distribution for the close-loop to the probability of high-quality product as design objectives,the objective function of the loss of quality robustness for this tolerance optimization design was established. Methods to determine the ratio of high-quality product and the variance of deviation distribution of the close-loop were also studied.The multi-objective optimization model was constructed by taking manufacturing cost and loss of quality robustness of product as objectives and reliability of fuzzy assembly and allowable tolerance range as constraints.Examples were provided to illustrate the application of this tolerance-robustness optimization design,and the genetic algorithm was used to complete the multi-objective design of tolerance.Results showed that this method could effectively coordinate manufacturing cost of component and the cost of loss on its quality robustness with best performance of optimization index.