加工工序非紧密衔接的车间调度策略

针对以往车间调度算法忽略非紧密衔接工序调度,从而导致调度结果不精确这一情况,提出了一种考虑工序间空闲时间延迟约束的调度策略,即解决加工工序非紧密衔接调度问题的方法。该方法在对由延迟约束造成的工序非紧密衔接型调度问题进行定义和研究的基础上,提出了标准工序、延迟工序和扩展加工工艺树概念。设计了一种将延迟约束转换为顺序约束的转换策略,使得转换后的非紧密衔接工序变为虚拟紧密衔接工序,并可采用经典车间调度算法调度。实例验证表明,该调度策略可有效地解决非紧密衔接工序调度问题,可在不增加算法复杂度的情况下,得到更为实用的调度方案。

Job-shop Scheduling Strategy for the Non-close-joining Operations

The traditional job-shop scheduling methods neglect non-close-joining operations and this results in imprecise scheduling result.A scheduling strategy is proposed which considers the lateness constraints of the idle time among operations,namely,a method for settling the problem that the operations are not close.Concepts such as standard operation,lateness operation and expansion processing tree are proposed.A conversion strategy,which coverts the lateness constraints into the sequence constraints and makes the non-close-joining operation become the virtual close-joining operation which can be scheduled by the classical job shop algorithm,is presented.The result of examples shows that our scheduling strategy is an effective solution to the non-close-joining operations scheduling problem and more practical scheduling result is obtained without increasing the complexity.