基于Petri网模型的柔性加工系统能耗动态优化调度方法

Dynamic Optimal Scheduling Method for Energy Consumption of Flexible Machining System Based on Petri Net Model

柔性加工系统加工过程中存在突发的动态事件,严重干扰已有调度计划的执行,难以维持较优的能耗指标。针对此问题,在建立柔性加工系统Petri网(flexible machining system Petri net, FMSPN)模型的基础上,考虑新任务插单和机器故障与修复两类事件,提出一种面向能耗目标的动态优化调度方法。在动态事件发生时刻,重新建立FMSPN模型,同时融合系统内各设备不同状态下的能量消耗规律,得到扰动发生时刻至加工完成时刻的能耗目标模型。基于动态规划方法对该能耗模型进行重新优化,求解扰动发生时刻后的系统生产调度计划。最后实例仿真验证了FMSPN模型在优化调度流程中的可靠性,以及此方法在动态扰动下的可行性。

Dynamic events occur in the process of the flexible machining system unexpectedly, which interfere the execution of the existing scheduling plan, and it is difficult to maintain better objects such as energy consumption. In view of this problem, a dynamic optimal scheduling method for energy consumption under the dynamic events with new task insertion and machine failure and repair is established based on the flexible machining system Petri net(FMSPN). At the moment when dynamic event occurs, FMSPN is re-established and the law of energy consumption under each equipment in the system is merged to obtain the total energy consumption model of the system from the moment to the makespan at the same time. Then the energy consumption model is re-optimized based on modified dynamic programming method, and the scheduling plan after the moment with the better energy consumption object is solved. Finally, the reliability of the FMSPN in the optimal scheduling process and the feasibility of the method under dynamic disturbances is verified by simulation.