火箭壳体加工的虚拟单元重构方法

Virtual cellular reconstruction method of rocket shell processing

针对火箭壳体加工车间新订单连续到达,排产方案重构频繁导致重构时间花销大、排产方案低效等问题,首先建立虚拟单元重构的多目标规划模型,以多批订单总生产时间、运输设备总运输距离以及车间生产设备负荷均衡因素为目标函数,以车间设备加工能力和火箭壳体加工工艺限制为约束条件;其次提出一种改进的NSGA-Ⅱ算法对模型进行优化求解,针对NSGA-Ⅱ算法局部搜索能力的不足,在NSGA-Ⅱ算法交叉过程中引入“首次改进”和“随机改进”两种局部搜索策略,提高该算法的局部搜索能力;最后基于超体积、均匀性两个多目标评价指标对提出的改进NSGA-Ⅱ算法与传统的NSGA-Ⅱ算法以及NSGA-Ⅲ算法进行比较,结合实例验证了改进NSGA-Ⅱ算法在进行火箭壳体虚拟单元重构时更加高效.

In view of the problems such as the continuous arrival of new orders in the rocket shell processing workshop,and the frequent reconstruction of the production scheduling scheme which leads to the high cost of reconstruction time and low efficiency of the production scheduling scheme,this paper establishes the mathematical model of multi-objective constraint virtual unit production.It takes the total production time of multiple orders,the total transportation distance of transportation equipment and load balancing factors of workshop production equipments as objective functions,workshop equipment processing capacity and rocket shell processing technology as constraint conditions.Then,an improved NSGAⅡalgorithm is proposed to solve the mathematical model.In order to improve the NSGA-Ⅱalgorithm’s local search ability,both the“first improvement”strategy and the“random improvement”strategy which improve the local search ability of the algorithm are introduced in interlace operation.Finally,the improved NSGA-Ⅱalgorithm is compared with the NSGA-Ⅱalgorithm and the NSGA-Ⅲalgorithm on the hypervolume and the spacing in a instance.As a result,the improved NSGA-Ⅱalgorithm performs more efficiently on virtual cellular reconstruction of rocket shell processing.