加工车间拉式控制策略研究

发布时间：2018-05-31 01:25

本文选题：瓶颈识别 + 约束理论　；参考：《沈阳工业大学》2017年硕士论文

【摘要】：为迎合消费者的个性化需求、满足市场的快速变化,企业的生产方式逐渐从大批量生产转变为更具柔性的多品种、小批量生产。拉式控制策略在降低生产成本、缩短生产周期、降低在制品库存等方面具有明显优势,并且多适用于重复性高、生产稳定的环境。然而,在多产品环境下,由于加工车间生产工艺和生产工序接续关系的复杂性往往会造成生产制造过程中生产线上的拥堵,即出现生产瓶颈,使得拉式策略的优势难以充分发挥。为此,本文研究了考虑瓶颈效应的制造系统拉式控制方法。为了识别生产流程中的瓶颈资源,本文首先对现有的主要瓶颈识别方法进行了分析和对比,综合生产系统的机器利用率和在制品平均等待时间,建立了多产品加工车间的瓶颈识别模型。在此基础上,对现有的推式(Push)和拉式(Pull)生产控制策略(PCS)进行了分析和总结,进而提出一种基于瓶颈的推拉结合的“双闭环”控制策略(CK-DBR控制策略),将拉式控制策略和约束理论集成应用于车间生产控制过程中。面向多产品生产过程,提出了一种定量在制品(CONWIP)控制策略和鼓—缓冲区—绳子(DBR)控制技术推拉结合控制策略。内环是由系统内部瓶颈触发的DBR控制结构,外环是由实际需求触发的CONWIP控制结构,通过内外“双闭环”控制,以期减少在制品库存和缩短平均生产周期,同时保持容量的柔性、较高的产出率和机器设备利用率。为验证所建立瓶颈模型和控制策略的有效性,本文应用离散事件仿真技术,完成了系统仿真。分别建立了Push、Kanban、CONWIP以及CK-DBR控制策略的排队网模型,并描述了四种控制策略的运行机理。进一步,本文针对多产品作业调度问题,基于ExtendSim平台进行仿真研究,分别选取多产品单一路径和混流路径为对象,对Push、Kanban、CONWIP以及CK-DBR这四种模式下的控制效果进行比较分析。分别讨论了原材料波动、订单波动、产品投产组合对调度结果的影响。仿真结果表明,拉式控制的有效性强于推式控制,而本文所提出的CK-DBR控制策略在降低在制品库存、缩短平均生产周期时间、均衡机器利用率等方面优于其他三种控制策略。此外,CK-DBR控制策略在降低生产过程波动造成的影响方面同样具有满意的性能,有利于系统的平稳运行。
[Abstract]:In order to meet the individual needs of consumers and meet the rapid changes in the market, the mode of production of enterprises has gradually changed from mass production to more flexible multi-variety and small batch production. The pull control strategy has obvious advantages in reducing the production cost, shortening the production cycle and reducing the in-process inventory, and it is more suitable for the environment of high reproducibility and stable production. However, in a multi-product environment, because of the complexity of the relationship between the production process and the continuity of the production process in the process of production, the production line will often become congested, that is, the production bottleneck will occur. Make the advantage of pull strategy difficult to give full play. Therefore, this paper studies the pull control method of manufacturing system considering bottleneck effect. In order to identify the bottleneck resources in the production process, this paper first analyzes and compares the existing main bottleneck identification methods, synthesizing the machine utilization ratio and the average waiting time of the in-process production system. The bottleneck identification model of multi-product processing workshop is established. On this basis, the existing production control strategies of push (push) and pull (pull) are analyzed and summarized. Furthermore, a "double closed loop" control strategy based on bottleneck is proposed. The pull control strategy and constraint theory are integrated into the process of workshop production control. For the multi-product production process, a quantitative in-process control strategy (CONWIP) and a push-pull combined control strategy for drum, buffer and rope control techniques are proposed. The inner loop is the DBR control structure triggered by the internal bottleneck of the system, and the outer loop is the CONWIP control structure triggered by the actual demand. The internal and external "double closed loop" control is used to reduce the in-process inventory and shorten the average production cycle, while keeping the flexibility of the capacity. High output rate and machine equipment utilization ratio. In order to verify the effectiveness of the bottleneck model and control strategy, the discrete event simulation technology is applied to complete the system simulation. The queuing network models of Push-Kanban-con WIP and CK-DBR control policies are established respectively, and the operation mechanism of four control strategies is described. Furthermore, aiming at the multi-product job scheduling problem, this paper simulates and studies the multi-product single path and mixed-flow path based on ExtendSim platform, and compares and analyzes the control effects of Push-Kanbanan ConWIP and CK-DBR. The effects of raw material fluctuation, order fluctuation and product combination on scheduling results are discussed respectively. The simulation results show that the pull control is more effective than the push control, and the proposed CK-DBR control strategy is superior to the other three control strategies in reducing the in-process inventory, shortening the average production cycle time and balancing the machine utilization ratio. In addition, the CK-DBR control strategy has the same satisfactory performance in reducing the impact caused by the fluctuation of the production process, which is conducive to the smooth operation of the system.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB49

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