Petri nets based deadlock prevention for flexible manufacturing systems has received much attention over the past decade, primarily due to the seminal work of Ezpeleta et al. in 1995. A Petri net based deadlock prevention mechanism is usually implemented by adding monitors or control places to a plant Petri net model such that liveness can be enforced. The significance of this methodology lies in that both a plant model and its supervisor are in a same formalism-Petri nets. Due to the inherent complexity of Petri nets, in theory, the number of additional monitors that have to been added to achieve liveness-enforcement purpose for an uncontrolled plant model is exponential with respect to the size of the model. This paper first proposes a systematic method to minimize the number of additional monitors in a liveness-enforcing Petri net supervisor such that the resultant net system has the same permissive behavior while liveness can still be preserved. Furthermore, for the liveness-enforcing Petri net supervisors of flexible manufacturing systems, which have some particular property, an algorithm is developed such that more permissive liveness-enforcing Petri net supervisors can be obtained after liveness-restrictive monitor removal. Compared with the existing techniques of eliminating redundant monitors in the literature, the complete state enumeration of a supervisor is avoided, which implies the high computational efficiency of the methods in this paper. Flexible manufacturing examples are used to demonstrate the proposed approaches.
%0 Journal Article
%1 citeulike:4074557
%A Li, Zhiwu
%A Hu, Hesuan
%D 2009
%J Computers & Industrial Engineering
%K citeulike deadlock, liveness, monitors, nets, petri, prevention, resources
%N 1
%P 53--62
%R 10.1016/j.cie.2008.03.013
%T On systematic methods to remove redundant monitors from liveness-enforcing net supervisors☆
%U http://dx.doi.org/10.1016/j.cie.2008.03.013
%V 56
%X Petri nets based deadlock prevention for flexible manufacturing systems has received much attention over the past decade, primarily due to the seminal work of Ezpeleta et al. in 1995. A Petri net based deadlock prevention mechanism is usually implemented by adding monitors or control places to a plant Petri net model such that liveness can be enforced. The significance of this methodology lies in that both a plant model and its supervisor are in a same formalism-Petri nets. Due to the inherent complexity of Petri nets, in theory, the number of additional monitors that have to been added to achieve liveness-enforcement purpose for an uncontrolled plant model is exponential with respect to the size of the model. This paper first proposes a systematic method to minimize the number of additional monitors in a liveness-enforcing Petri net supervisor such that the resultant net system has the same permissive behavior while liveness can still be preserved. Furthermore, for the liveness-enforcing Petri net supervisors of flexible manufacturing systems, which have some particular property, an algorithm is developed such that more permissive liveness-enforcing Petri net supervisors can be obtained after liveness-restrictive monitor removal. Compared with the existing techniques of eliminating redundant monitors in the literature, the complete state enumeration of a supervisor is avoided, which implies the high computational efficiency of the methods in this paper. Flexible manufacturing examples are used to demonstrate the proposed approaches.
@article{citeulike:4074557,
abstract = {{Petri nets based deadlock prevention for flexible manufacturing systems has received much attention over the past decade, primarily due to the seminal work of Ezpeleta et al. in 1995. A Petri net based deadlock prevention mechanism is usually implemented by adding monitors or control places to a plant Petri net model such that liveness can be enforced. The significance of this methodology lies in that both a plant model and its supervisor are in a same formalism-Petri nets. Due to the inherent complexity of Petri nets, in theory, the number of additional monitors that have to been added to achieve liveness-enforcement purpose for an uncontrolled plant model is exponential with respect to the size of the model. This paper first proposes a systematic method to minimize the number of additional monitors in a liveness-enforcing Petri net supervisor such that the resultant net system has the same permissive behavior while liveness can still be preserved. Furthermore, for the liveness-enforcing Petri net supervisors of flexible manufacturing systems, which have some particular property, an algorithm is developed such that more permissive liveness-enforcing Petri net supervisors can be obtained after liveness-restrictive monitor removal. Compared with the existing techniques of eliminating redundant monitors in the literature, the complete state enumeration of a supervisor is avoided, which implies the high computational efficiency of the methods in this paper. Flexible manufacturing examples are used to demonstrate the proposed approaches.}},
added-at = {2017-09-08T10:52:59.000+0200},
author = {Li, Zhiwu and Hu, Hesuan},
biburl = {https://www.bibsonomy.org/bibtex/2afb50ab2eb4c6fae67e76a0e7a77105c/fernand0},
citeulike-article-id = {4074557},
citeulike-linkout-0 = {http://dx.doi.org/10.1016/j.cie.2008.03.013},
doi = {10.1016/j.cie.2008.03.013},
interhash = {c52e369bc40c281d1324d5700508d585},
intrahash = {afb50ab2eb4c6fae67e76a0e7a77105c},
issn = {03608352},
journal = {Computers \& Industrial Engineering},
keywords = {citeulike deadlock, liveness, monitors, nets, petri, prevention, resources},
month = feb,
number = 1,
pages = {53--62},
posted-at = {2009-02-20 12:16:35},
priority = {2},
timestamp = {2017-09-08T10:53:23.000+0200},
title = {{On systematic methods to remove redundant monitors from liveness-enforcing net supervisors☆}},
url = {http://dx.doi.org/10.1016/j.cie.2008.03.013},
volume = 56,
year = 2009
}