Abstract
To solve the problem of deadlocks in Flexible Manufacturing Systems (FMS), this paper presents an effective deadlock-free policy for a special class of Petri nets, S <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> PMR. The deadlock avoidance policy (DAP) of Conjunctive/Disjunctive Resources Upstream Neighborhood (C/D RUN) is combinated with the deadlock prevention policy (DPP), and the underlying (sequential) resources are allocated reasonably to guarantee the absence of deadlock states and processes. Siphons in an S <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> PMR net model are distinguished by elementary and dependent ones, a set of generalized mutual exclusion constraints (GMEC) expressed by the marking vector can be formalized from the set of elementary siphons. Then monitors based on the GMEC are added only to the elementary siphons of the plant model such that all siphons in the S <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> PMR net are all invariant-controlled and no emptiable siphon is generated due to the addition of the monitors. A practical application is utilized to illustrate the validity of the proposed novel method to design deadlock-free supervisores for S <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> PMR net model.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.