【作者】 李倩；

【导师】 侯媛彬；

【作者基本信息】 西安科技大学 ， 控制理论与控制工程， 2011， 硕士

【摘要】 本文以我校学科群实验中心的自动化物流系统为研究平台,针对该物流系统的任务规划提出了一种新的Petri网分解方法,对所建的物流系统的Petri网模型∑进行分解,分析判断出此物流系统的任务规划合理有效可避免死锁。在此结论的基础上,完成了我校自动化物流系统的控制系统开发,实现了出库和移库功能。论文介绍并分析了我校学科群实验中心自动化物流系统的硬件组成。在了解了各核心部分结构和参数的基础上采用Petri网理论对该物流系统建立Petri网模型∑,并对该模型各要素给出了定义。针对自动化物流系统的任务规划,提出一种新的Petri网分解方法——基于变迁指标和库所指标融合的Petri网分解方法。推导出了最小子网和原Petri网之间的可重复性和有界性之间的关系,提出并证明一些相应的推论。对所建立的Petri网模型∑先进行基于变迁指标的分解得出物理含义明确的子网,再采用基于库所指标的分解得到融合了T网和S网特性的最小子网。通过分析该最小子网,得出Petri网模型的活性和有界性,据此推断出物流系统的任务规划合理有效。该方法大大减少了直接分析子网或原Petri网模型的计算量,可避免全局或局部死锁,为系统良好运行提供了依据。以物流系统Petri网模型的分析结果为依据,通过设计数据库、设计操作界面、根据所建立的Petri网模型∑开发出库移库功能的软件完成了该物流系统的控制系统开发。经过多次现场调试及实验证明本文所开发的自动化物流系统的控制系统能够正常有效的运行。堆垛机能够准确的执行出库和移库指令(入库功能在07级研究生秦国柱的论文中完成)。更多还原

【Abstract】 The research platform of this thesis is the automatic logistics system in Subjects Experimental Center of XUST (Xi’an University of Science and Technology). Aiming at this automated logistics system task planning, a new decomposition method of Petri net is given in this paper. Through decomposing the Petri net model of the logistics system by the new decomposition method, a conclusion is drawn:this logistics system’s task planning is reasonable and without globally or local deadlocks. Based on this conclusion,the development of this automatic logistics system’s control system is completed, and functions of warehouse discharge and moving are accomplished.The hardware of the automatic logistics system in Subjects Experimental Center of XUST is introduce and analysed. Based on understanding each core part’s structure and parameters, a model based on Petri nets theory of Automated Logistics System is presented and defined.Aiming at the automated logistics system task planning, a new decomposition method of Petri net based on the index of transition and index of places fusion is given in this paper. The relationship of repeatability and boundedness between minimum subnets and the original Petri net model is deduced, and some corresponding reasonings are proposed and proved. Through decomposing the Petri net model of the logistics system by decomposition method of Petri net based on the index of transition subnets which physical meaning is clear are gotten. Then through decomposing these subnets by decomposition method of Petri net based on index of places minimum subnets which fuse characteristics of T-net and S-net are gotten. According to the analysis of the minimum subnet the activity and boundedness of this Automated Logistics System is inferred. Then, according to the result of the analysis a conclusion is drawn:this logistics system’s task planning is reasonable. Using his method greatly reduced the calculation of analyzing the subnets or original Petri nets model directly, without globally or local deadlocks which provides a basis of good working for this system.On the basis of that conclusion, through designing database, designing interface, developing functions of warehouse discharge and moving based on the established Petri nets model E this automatic logistics system’s control system is completed. After many commissioning and experiments, it is proved that this control system of the automatic logistics system can work very well. The stacker can executive instructions of warehouse discharge and moving accurately (Warehouse entry function is accomplished in the paper of graduate student Qin GuoZhu).更多还原