Research On Energy-saving Scheduling Of Flexible Job Shop By Considering The Equipment Availability

Job shop, as a basic manufacturing system unit, is the main activity of mechanical manufacturing enterprises as well as the main site of material flow, energy consumption and production process. To improve the efficiency and decrease the cost, operational optimization technique has been always a hot topic in optimal control of manufacturing system. In the past, researchers focus more on related theories and methodologies which mainly consider time and cost in objective function. However, energy consumption and efficiency are rarely considered. In fact, with different machines, same operation consume different energy. Thus, reaso nable scheduling can effectively reduce total processing energy consumption and improve the energy efficiency. And an energy-saving related flexible job shop scheduling is significant to operational optimization.To achieve the optimization of makespan and energy consumption from the point of reasonable processing arrangement, the paper was researching on energy-saving scheduling problem of flexible job shop. The mainly contributes following improvements.First, expounded the effect of scheduling on energy-saving in job shop basic on the analysis of energy flow. Basic on the energy-saving scheduling problem of job shop around a kind of flexible equipment, an energy-saving scheduling model of job shop with flexible equipment was built. The model's optimization objective is minimizing the makespan and energy consumption. An Immune Genetic Algorithm with double coding was adopted to solve the function.Then, the pre-scheduling and rescheduling methods in energy-saving scheduling model were studied. In pre-scheduling, the influence of uncertainty factors on the process was analyzed. A pre-scheduling method considering the equipment availability was designed. And the availability model and pre-scheduling process were studied. In rescheduling, it's mainly focused on the rescheduling response is not timely caused by the abnormal state information. The on- line identification of the abnormal state, rescheduling mechanism and rescheduling policy were analyzed.Finally, based on the above research, the related application experiments were designed. The energy-saving of the method was analyzed by comparing the cases. And the pre-scheduling and rescheduling method were verified by setting the abnormal state in the process.