离散制造车间生产现场建模及驾驶控制技术的研究

发布时间：2018-09-17 17:39

【摘要】：信息技术的发展推动着企业生产方式的变革。越来越多的中小离散制造企业希望应用信息化手段来管理车间生产现场,实现提高企业生产效率、降低生产成本和提高产品质量的目标。然而企业信息化深入到车间生产管理时,经常会遇到很多问题。论文以构建车间生产现场驾驶舱控制系统为目标,使得管理者可以不必亲临生产现场,通过驾驶舱就能获取车间现场的实时状态,并可以控制生产过程的运行。构建驾驶舱控制系统需要解决三个关键技术：车间现场生产状态的建模、车间生产状态的偏差分析以及车间动态生产调度。这三个关键技术也正是车间生产管理信息化所面临的问题。车间现场生产状态的模型是研究其他关键技术的基础。车间生产现场的基本构成要素是工件和工作单元,两者通过工序联系在一起。三者的结合体抽象成信息节点,分析了信息节点之间的关系,并对信息节点的属性和行为作了描述。以信息节点为基本单元,描述了车间现场的生产状态。分析了车间现场的生产数据与工件状态、工序状态和工作单元的状态的关系RSD,以及信息节点状态与工件状态、工序状态和工作单元的状态的关系RSI,建立了车间现场生产数据与信息节点状态的对应关系,建立了车间现场生产状态的模型。应用信息节点的模型,简化了车间现场生产状态的建模。车间现场理想的生产状态由基准生产过程确定,基准生产过程由作业计划调度确定。实际的生产过程按照基准生产过程确定的节点激活顺序运行,并期望实际生产过程与基准生产过程保持一致。但由于车间生产现场存在大量的随机因素,使得实际生产过程经常偏离基准生产过程,形成实际生产状态与理想生产状态的偏差e(t)。只有同质才能比较,因此把偏差e(t)细化成生产时间偏差和生产成本偏差等,并给出了计算方法。通过引入信息节点关联模块的概念,分析了偏差e(t)在车间生产过程中传播的机理,这是分析预估偏差的基础。实际的车间生产过程是动态变化的,因此需要不断的重调度才能满足实际生产的需求。动态生产调度以提高企业生产效率、降低生产成本和提高产品质量为目标,是多目标优化问题。为了把多目标优化问题转换成单目标优化问题,提出了当量成本的概念。通过分析时间、成本和质量的关系,把时间、成本和质量转换成当量成本,并以当量成本最小作为调度问题的目标函数,把生产状态的偏差不超过设定的阈值作为约束条件。根据车间现场的生产状态,分析了几种触发动态生产调度的典型情况,针对这些情况的特点,给出合适的调度策略和调度算法,实现当量成本最小的调度目标。动态生产调度的实时性要求调度算法必须高效,论文结合启发式规则和邻域搜索的高效性,以时间邻域内的最优解作为启发式搜索方向,提出了信息节点分段寻优算法。在此研究的基础上,对驾驶舱控制系统的体系结构进行了研究,并结合实证案例对论文的理论和方法进行了阐述。
[Abstract]:More and more small and medium-sized discrete manufacturing enterprises hope to use information technology to manage the workshop production site to achieve the goal of improving production efficiency, reducing production costs and improving product quality. Many problems. The aim of this paper is to construct the cockpit control system of workshop production site, so that managers can obtain the real-time state of workshop site and control the operation of production process without visiting the production site.
The construction of cockpit control system needs to solve three key technologies: the modeling of workshop production status, the deviation analysis of workshop production status and the dynamic production scheduling.
The model of workshop production status is the basis of other key technologies.The basic elements of workshop production site are workpiece and work unit,which are connected by working procedure.The combination of them is abstracted into information nodes,the relationship between information nodes is analyzed,and the attributes and behaviors of information nodes are described. The information node is the basic unit, which describes the production state of the workshop site. The relationship between the production data and the workpiece state, the working procedure state and the working unit state is analyzed, and the relationship between the information node state and the workpiece state, the working procedure state and the working unit state is analyzed. According to the corresponding relation of node state, the model of workshop production state is established. The model of information node is applied to simplify the modeling of workshop production state.
The ideal production state of the workshop site is determined by the benchmark production process and the benchmark production process is determined by the job scheduling. The actual production process runs in the order of node activation determined by the benchmark production process, and the actual production process is expected to be consistent with the benchmark production process. Only homogeneity can be compared, so the deviation e (t) is refined into production time deviation and production cost deviation, and the calculation method is given. By introducing the concept of information node correlation module, the deviation is analyzed. The propagation mechanism of differential e (T) in the workshop production process is the basis for analyzing the prediction bias.
The actual workshop production process is dynamic, so it needs constant rescheduling to meet the actual production needs. Dynamic production scheduling is a multi-objective optimization problem with the objective of improving production efficiency, reducing production costs and improving product quality. By analyzing the relationship among time, cost and quality, the time, cost and quality are converted into equivalent cost, and the minimum equivalent cost is taken as the objective function of scheduling problem, and the deviation of production state is not exceeded the set threshold as the constraint condition. According to the characteristics of these situations, a suitable scheduling strategy and algorithm are proposed to achieve the goal of minimizing the equivalent cost. The real-time performance of dynamic production scheduling requires that the scheduling algorithm must be efficient. A search algorithm for information nodes is proposed.
On the basis of this research, the system structure of the cockpit control system is studied, and the theory and method of the paper are expounded with an empirical case.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TH186

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