针对数控加工中心机床工艺路线工序集中、工步复杂、加工刀具类型多带来的排序规模大、成本核算困难的特点,用一种改进的遗传算法实现工艺路线的优化。算法中以加工时间最短和加工成本最低两个目标作为组合的优化目标函数,从而构造出适应度函数。改进的算法对不同的加工面设立了加工标识位码,并制定了加工标识位码的优先原则、加工标识位码相同原则;优先原则实现了工艺路线排序原则;相同原则实现了工步中的刀具类型的选择及刀具成本的核算。由于算法中加入了加工标识位码相同原则,去除掉不必要工艺路线组合方案,从而使得算法收敛更快。通过实例对算法进行了系统仿真实验,得出了最优路线方案,验证了方案的合理性。
Aiming at characteristics of large scale in sorting and difficulties in cost accounting due to concentration of process,complicated working step and more types of tools in the routing of NC machining center,an improved genetic algorithm is used to optimize the routing,in which the optimal goal function is the combination of the shortest machining time and lowest cost,thus fitness function is constructed out.The improved algorithm set up bit codes for identifying different machining surfaces with priority theory and the same principles of bit code,in which the priority theory realize the sorting of the routing and the same principle realize tools selecting and tools accounting cost in the process.With the joining the same principles,unnecessary routing is removed which make the algorithm converge faster.The optimal routing scheme obtained through systematic simulation is verified to be reasonable.