Distributed Maximally Permissive Nonblocking Control of Flexible Manufacturing Systems

2013 ◽  
pp. 36-60
Author(s):  
Renyuan Zhang ◽  
Yongmei Gan ◽  
W. M. Wonham ◽  
Zhaoan Wang
Keyword(s):  
Distributed Control ◽  
Petri Net ◽  
Flexible Manufacturing ◽  
Flexible Manufacturing Systems ◽  
Manufacturing Systems ◽  
Control Policy ◽  
Recent Theory ◽  
Automatic Guided Vehicle ◽  
Resource Allocation Systems ◽  
Production Cell

In recent years, a great deal of research has been focused on preventing deadlock in Flexible Manufacturing Systems. Policies based largely on Petri net models have been presented in the literature. Recently, a quite different approach has been developed based on supervisory control theory, and it has been adapted to solve the nonblocking maximally permissive control problem in various resource allocation systems, such as an Automatic Guided Vehicle system and a Production Cell. In this chapter, the authors obtain the corresponding control policy for a Flexible Manufacturing System, and from it derive an equivalent distributed control using the recent theory of supervisor localization.

Petri Net Channelized-Based Deadlock Prevention Policy for Flexible Manufacturing Systems

2011 ◽  
Vol 317-319 ◽  
pp. 552-555
Author(s):  
Yi Sheng Huang ◽  
Ter Chan Row
Keyword(s):  
Control System ◽  
Petri Net ◽  
Flexible Manufacturing ◽  
Flexible Manufacturing Systems ◽  
Manufacturing Systems ◽  
Control Policy ◽  
Original Model ◽  
Deadlock Prevention ◽  
Prevention Policy ◽  
Maximal Permissiveness

Petri nets are employed to model flexible manufacturing systems (FMSs). However, the system deadlocked are possible happened. The conventional deadlock prevention policies are always to forbid the system entering the deadlock by using the control places. To obtain a live system, some dead markings must be sacrificed in the traditional policies. Therefore, the original reachability states of the original model can not be conserved. However, this paper is able to maintain all the reachability states of the original net and guaranty the control system live. Under our control policy, all number of reachability states of the original net will be preserved. Finally, two examples are performed that can reach the maximal permissiveness for FMSs using Petri net models (PNMs).

A Channelized Deadlock Prevention Policy for Flexible Manufacturing Systems Using Petri Net Models

2011 ◽  
Vol 284-286 ◽  
pp. 1498-1501
Author(s):  
Yi Sheng Huang ◽  
Ter Chan Row
Keyword(s):  
Petri Net ◽  
Flexible Manufacturing ◽  
Flexible Manufacturing Systems ◽  
Manufacturing Systems ◽  
Control Policy ◽  
Deadlock Avoidance ◽  
Deadlock Prevention ◽  
Deadlock Detection ◽  
Prevention Policy ◽  
Maximal Permissiveness

Deadlock prevention, deadlock detection and deadlock avoidance strategies are used to solve the deadlock problems of flexible manufacturing systems (FMSs). The conventional prevention policies were always attempt to prevent the system entering the deadlocked situation by using a few control places. On can know that one prohibits the deadlocked markings, some dead markings will be sacrificed. Therefore, the reachability states will become less than the initial net. However, our goal is to preserve all the reachability states of the initial net. Under our control policy, the deadlocks or deadlock zone will be channelized to live markings such that all the dead markings in reachability states will be conserved. Finally, an example is performed and can obtain the maximal permissiveness of a Petri net model. The other examples are all getting the same result. To our knowledge, this is the first work that employs the channelized method to prevent the deadlock problem for FMSs.

A Computationally Improved Control Policy for FMS Using Crucial Marking/Transition-Separation Instances

2013 ◽  
pp. 61-82
Author(s):  
Yi-Sheng Huang ◽  
Yen-Liang Pan
Keyword(s):  
Petri Net ◽  
Flexible Manufacturing ◽  
Flexible Manufacturing Systems ◽  
Manufacturing Systems ◽  
Control Policy ◽  
Deadlock Avoidance ◽  
Deadlock Prevention ◽  
Deadlock Detection ◽  
Optimal Controllers ◽  
Unique Method

Deadlock prevention, deadlock detection, and deadlock avoidance strategies are used to solve the deadlock problems of Flexible Manufacturing Systems (FMS). The theory of regions has been recognized as the unique method for obtaining maximally permissive controllers in the existing literature. All legal and live maximal behavior of a Petri net model can be preserved by using a Marking/Transition-Separation Instance (MTSI). However, obtaining all sets of MTSIs is an extremely time consuming problem. This work proposes Crucial Marking/Transition-Separation Instances (CMTSIs) that allow designers to employ few MTSIs to deal with deadlocks. The advantage of the proposed policy is that a maximally permissive controller can be obtained with drastically reduced computation. Experimental results, by varying the markings of given net structures, indicate that it is the most efficient policy to obtain optimal controllers among existing methods based on the theory of regions.

An Efficient Deadlock Avoidance Policy for FMS Using ROPN

2014 ◽  
Vol 998-999 ◽  
pp. 751-754
Author(s):  
Yu Ming Zhao ◽  
Xiang Ju Chai ◽  
Li Zhen Zhao
Keyword(s):  
Petri Nets ◽  
Petri Net ◽  
Control Strategy ◽  
Flexible Manufacturing ◽  
Flexible Manufacturing Systems ◽  
Manufacturing Systems ◽  
Control Policy ◽  
Deadlock Avoidance ◽  
Concurrent Execution ◽  
Better Than

This article shows a composed method for modeling the concurrent execution of working processes in flexible manufacturing systems (FMS) by a special class of Petri nets named Resource Oriented Petri nets (ROPN). Essentially, the type of net comes from the availability of system resources. The analysis of ROPN is used to characterize deadlock situations in terms of full markings for certain structure named PPC. For the sake of preventing the system from deadlocks, a policy is proposed based on a series of restrictions for resource allocation, without considering the presence of unmarked siphons in Process Oriented Petri net (POPN). Finally, a control strategy of deadlock avoidance is designed for ROPN, which is better than other control policy.

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