带有限缓冲区的知识化制造单元无死锁调度  

Deadlock-free scheduling of knowledgeable manufacturing cell with limited buffers

作　　者：杨宏兵[1,2] 严洪森[2] 

机构地区：[1]苏州大学机电工程学院,苏州215021 [2]东南大学复杂工程系统测量与控制教育部重点实验室,南京210096

出　　处：《系统工程理论与实践》2010年第12期2259-2268,共10页Systems Engineering-Theory & Practice

基　　金：国家自然科学基金(51005160;70971085);江苏省高校自然科学研究项目(10KJB410001);苏州大学青年教师自然科学基金(Q3117917)

摘　　要：鉴于制造系统无死锁随机调度问题研究的缺乏,在加工时间、工件到达以及产品需求到达均为随机的生产环境下,研究了带有限缓冲区的知识化制造单元无死锁随机调度问题.针对自动机对定量指标描述能力的不足,首先给出了一种费用自动机概念.在同时考虑工件加工、库存以及缺货费用的情况下,采用无限时域折扣准则下马尔可夫链建立了单元的费用目标函数,通过一致化技术对目标函数进行离散化处理,得到目标函数的随机动态规划模型,分析并证明了单元最优目标值函数的性质.为了克服离散状态空间组合所产生的维数灾问题,提出了一种基于仿真和函数逼近的启发式近似动态规划算法对模型进行求解.在上述研究基础上,构建了一种单元无死锁随机调度策略,以保证单元安全高效地运行.最后,通过实例研究对无死锁调度策略进行了验证.Aiming at insufficient investigation of deadlock-free stochastic scheduling problem in manufacturing systems, under the stochastic production environment with uncertain job arrival, processing times and product demands, the deadlock-free stochastic scheduling is studied for KMC with limited buffers. Due to the lack of ability to describe quantitative index, the concept of cost automata is given firstly. Con- sidering the cost of part processing, inventory and backlog simultaneously, the cost objective function is constructed based on infinite horizon Markov chain with a discount factor, a stochastic dynamic program- ming model is obtained by the uniformization technique, and then we analyze and derive the properties of optimal objective function. To overcome the curse of dimensionality arising from combination of discrete state-space dimensions, a heuristics approximate dynamic programming algorithm based on simulation and function approximation is proposed to solve the stochastic dynamic programming model. On the basis of the above, the deadlock-free stochastic scheduling strategy is derived to ensure the efficient operation of KMC. Finally, a case is given to demonstrate ~d validate the effectiveness of the dead-free scheduling strategy.

关 键 词：自动机 无死锁调度 近似动态规划 知识化制造单元 

分 类 号：TP14[自动化与计算机技术—控制理论与控制工程]