柔性制造系统鲁棒死锁控制研究

The deadlock analysis and control of flexible manufacturing systems (FMS) based on Petri nets have been a cutting-edge technology and hot research topic in automation. A large number of deadlock control policies based on Petri nets have been proposed for different kinds of FMS. However, most of them are developed on the premise that the resources in a system under consideration are reliable. Actually, resource failures are usually inevitable in real-world systems, which pose challenges in supervisory control of contemporary FMS. In case of resource failures, the existing deadlock control policies are always no longer in force and deadlocks in the disturbed system may be caused. The project aims to deal with deadlock problems in FMS with unreliable resources. The major points of this project are presented as follows: (1) FMS with unreliable resources are modeled with Petri nets. Based on structural analysis techniques, we propose controllability conditions for siphons in the Petri net models which carry unreliable resource information. (2) Robust deadlock control policies are designed for Petri net models of FMS with unreliable resources and then robust Petri net liveness-enforcing supervisors are obtained. (3) Robust Petri net supervisors are optimized in term of behavioral permissiveness, structural complexity, and computational complexity. Finally, we perform research on experimental systems. This project is also of significance in both theory and practice to the supervisory control of FMS in a Petri net formalism.

基于Petri网的柔性制造系统死锁分析与控制是自动化领域的前沿技术和热点课题.针对不同物理系统,人们研究了大量基于Petri网的死锁控制策略,然而大部分策略是假定系统资源运行良好的情况下设计的.而在实际生产系统中资源故障是常见现象.当系统出现资源故障时,已有控制策略通常不具备适应性,受扰系统再次面临死锁问题. 本项目致力于解决存在资源不可靠因素下,柔性制造系统的Petri网鲁棒死锁控制问题.主要研究内容有:(1)存在资源不可靠因素柔性制造系统的Petri网建模及其结构分析, 给出所建Petri网模型中信标可控条件;(2)存在资源不可靠因素柔性制造系统的Petri网死锁控制策略研究,设计鲁棒Petri网监督控制器;(3)优化设计行为最大许可、结构简单且计算高效的鲁棒Petri网控制器,结合具体系统,进行实验研究.该项目对柔性制造系统的监督控制理论应用于实际生产系统具有一定的理论和实践价值.

基于Petri网的柔性制造系统死锁分析与控制是自动化领域的前沿技术和热点课题。针对不同物理系统，人们研究了大量基于Petri网的死锁控制策略，然而大部分策略是假定系统资源运行良好的情况下设计的。而在实际生产系统中资源故障是常见现象。当系统出现资源故障时，已有控制策略通常不具备适应性，受扰系统再次面临死锁问题。本项目主要基于Petri网结构分析技术及整数规划技术，研究了存在资源不可靠因素下，柔性制造系统的Petri网鲁棒死锁控制问题。项目执行期间，项目组取得了一定的研究成果，项目组发表SCI检索期刊论文7篇，EI检索期刊论文1篇，发表/录用国际会议论文2篇。主要研究成果包括：研究了几种柔性制造系统存在不可靠信息的Petri网建模方法。针对所建模Petri网模型，基于结构分析，给出信标可控条件，设计出鲁棒的Petri网活性监督控制器。结合信标理论和区域理论、利用整数规划迭代计算等方法提高鲁棒Petri网活性监督控制器的性能。给出新的Petri网结构-数据决策弧，设计最大许可行为的Petri网控制器并使控制器具有更少的控制库所数目。本项目在系统建模/死锁控制器设计阶段，考虑资源不可靠因素，创新性地设计鲁棒死锁控制器，使得Petri网监督控制器对实际柔性制造系统具有一定的理论和实践价值。