Synergistic Activity Construction Of Large-scale Automated Manufacturing Systems

The Flexible Manufacturing System(FMS)is widely used in the production of advanced manufacturing.Due to the flexible processing mode,it can shorten the production cycle of the product and improve the processing accuracy and production efficiency under the premise of ensuring product quality,thereby reducing production costs.However,the internal structure of large-scale manufacturing systems is complicated and the reliability is poor,so it is difficult to extend flexible manufacturing systems to large-scale manufacturing systems.When the system fails,it is difficult to troubleshoot the problem in a short time,so it is exactly necessary to ensure the reliable operation of large manufacturing systems.In this paper,we use Petri nets as a tool to model large-scale flexible manufacturing system.Each subsystem constituting the large-scale manufacturing system is firstly modeled,and then the module method is used to synthesize under certain restrictions.The synthesized system must be able to run reliably without performing a posteriori analysis.First proposes six restriction rules which need to be met when the Wighted Resource Control Network(WRCN)is merged.This article establishes these rules to make large-scale networks meet the activity.These rules are described as: WRCNs that have activity and do not have degradation behavior,when synthesized through common transition paths,the only source place that can directly or indirectly trigger the common transition path,and the product of the token in the resource place and all the output arc weights in the source place is greater than the product of the token in the source place and the arc weight in the resource place.Large nets synthesized following these rules must satisfy activity.WRCN synthetic network can only model resource behavior.Therefore,based on WRCN this paper studies the Process Control Net With Wighted Resource(PCNWR),which can model both resource behavior and process behavior.When Process Control Network(PCN)and WRCN are synthesized through continuous common transition paths,the number of tokens in the PN working place are less than the number of tokens in the WRCN resource place which have at least two common transition paths with the PN,and there is no degradation in all subnets.The synthesized PNWR must have activity.Finally,the above model uses a linear programming method which does not need to directly calculate siphons for liveness detection,further verifies the correctness and practicability of the restriction rules.Compared with the existing theory of subnet synthesis,the subnet following the restriction rules proposed in this paper must satisfy the activity after synthesis,and is no need for a posterior analysis of the result network.For large-scale manufacturing systems,it saves a lot of time to calculate siphons.These rules are not only applicable to the most common singleresource processing mode,but also to the generalized multi-resource processing mode.Synthetic networks can be used in automatic manufacturing systems model resource behavior as well as can model more complex process behaviors,such as complex resource sharing,parallel structures,integrated devices,and disassembly processes.In brief,the restriction rules proposed in this article reduce the difficulty of active construction of large-scale flexible manufacturing systems,improve production reliability,and will be more conducive to popularization.The research results in this paper can support flexible manufacturing systems for large-scale multi-variety processing and production,at the same time improve production efficiency and ensure production quality.