关键词: STEP-NC技术, 工艺路线优化, 操作优先图, 智能搜索算法, 遗传算法

Abstract: To meet the requirements of STEP-NC technology and to solve the non-linear process planning problem, the existing problems in process planning optimization and its related constraints were discussed on the basis of analyzing STEP-NC data model based on machining features. The hybrid algorithm was proposed by integrating intelligent search of operation precedence graph with genetic algorithm. The compulsive constraints were firstly considered in the sequence of operations, and the alternative operation sequences were acquired by intelligent search algorithm based on operation precedence graph. This algorithm was acted as the initial population for the next genetic algorithm. The selections of machine tool, tool and tool approach direction were all taken into account, by taking the lowest machining cost as optimization objective function, the effective process planning optimization decision was achieved through operation of genetic algorithm's copy, cross and variation according to optimization constraints. The optimal or near optimal process route which satified the workshop requirements was obtained. An example was used to demonstrate the feasibility and effectiveness of proposed algorithm in parts process planning optimization oriented to STEP-NC.

Key words: STEP-NC technology, process planning optimization, operation precedence graph, intelligent search algorithm, genetic algorithms