Multi-objective Dynamic Scheduling For Flexible Flow Mould Heat-treatment Workshop

Mold heat treatment is an important component in the process of die manufacturing, which results show that the delivery time is poor, high energy consumption, quality is not stableand other factors make it a key factor affecting the rapid and healthy development of the mold industry. Therefore, how to establish effective production control system of heat treatment has important practical significance.The jobs of heat-treatment belong to multiple incompatible job families and have re-entrant and batch processing characteristics. Their arrivals aredynamic and uncertain. Considering these characteristics stated above, heat-treatment shop floor scheduling is differentiated into certain re-entrant tempering and uncertain re-entrant tempering with time constraints. Based on the common features and divergences of these two types of scheduling,this paper is divided into the following four parts.(1)The optimization model of multi objective die heat treatment plant is established, which is based on the time, energy saving and quality stability.By doing business and compromise programming model, the multiple objectives are transformed into a single objective,And the weight of each target can be adjusted freely by the weight coefficient.(2)Under the deterministic reentrant tempering conditions to construct the corresponding scheduling mechanism established a set of event triggered real-time scheduling heuristic algorithm, and through the embedded in multilayered compromise programming model of multiple targets for effective coordination. Finally, MATLAB simulation shows that the proposed algorithm is superior to the two traditional rules.(3)Under the condition of random re-entry and tempering time, the corresponding scheduling mechanism is constructed. To extend the deterministic annealingscheduling algorithm, a dynamic batch scheduling algorithm is established for non-identical parallel machine under the condition of random re-entry and tempering time. MATLAB simulation shows that the proposed algorithm is superior to the two traditional rules.(4)In this paper, the dynamic batch scheduling algorithm is proposed, and the simulation research is carried out. The adaptability of the algorithm is analyzed from four aspects, which are the strength of the workpiece, the strength of the work piece delivery period, the deviation of the nominal transfer rate and the window size.