中速电火花线切割加工工艺建模与多目标优化研究
Modeling and Multi-objective Optimization of Medium-speed WEDM Process

利用正交试验设计，对中速电火花线切割加工过程中的脉冲宽度、脉冲间隙、峰值电流、丝筒速度和跟踪系数等工艺条件进行试验的优化设计。使用广义回归方法分别对加工参数与表面粗糙度（Ra）和材料去除率（MRR）之间的关系建模，并通过信噪比分析得出影响表面质量和加工效率的主要因素。表面质量随着电流的增加而变差；材料去除率随着脉宽和电流的增加而增加，丝速和跟踪系数对材料去除率几乎没有影响。运用非支配排序遗传算法（NSGA2）对MRR和Ra进行两目标优化，并对参数不同取值的优化结果进行了比较；NSGA2中的遗产操作参数对优化结果影响很小，算法具有鲁棒性。当种群规模和遗传代数足够大时，可以得到足够多且分布均匀的Pareto前沿。
The orthogonal experimental design method was used to optimize its technological parameters such as pulse-on time, pulse-off time, peak pulse current, wire cylinder speed and tracking coefficient of the medium-speed WEDM process. The relationship between process parameters and surface roughness (Ra) and the material removal rate (MRR) were modeled with the generalized regression method. Then the important factors that affect Ra and MRR are obtained with the signal to noise ratio (S/N Ratio) analysis. Finally, the non-dominated sorting genetic algorithm II (NSGA2) was used to optimize MRR and Ra. The effects of the corresponding parameters on optimal results were discussed. When the population size and the genetic number are larger enough, the adequate and uniform distribution Pareto front can be obtained