Colored Resource-Oriented Petri Net Based Ladder Diagrams for PLC Implementation in Reconfigurable Manufacturing Systems

Husam Kaid,Zhiwu Li,Abdulrahman Al-Ahmari

doi:10.1109/access.2020.3041408

Abstract

A typical example of discrete event systems (DESs) is a reconfigurable manufacturing system (RMS) whose can be changed and become more complicated during its operation. Thus, an effective tool needs to be developed to create both high- and low-level DES implementation. The ladder diagram (LD) is a common programming method for controlling DESs. Petri nets (PNs) represent the most important graphical and mathematical tool that can be used to provide an integrated solution for the design, modeling, analysis, control, and implementation of DESs. Various types of PN-based LDs are developed for DESs, which have high structural complexity of the LDs. Therefore, an approach that can facilitate the elimination of the LDs’ structural complexity needs to be developed. The main objective of this paper is to develop a two-step approach for LDs implementation for RMSs with dynamic changes. First, a colored resource-oriented Petri net (CROPN)-based algorithm is proposed for a rapid and valid configurations of an RMS. Second, a ladder diagram colored resource-oriented Petri net (LDCROPN) is developed to convert the CROPN into an LD. The developed approach is evaluated using examples in the literature. Moreover, the results demonstrate the effectiveness of the developed approach for LD implementation under RMS specification changes.

Highlights

A reconfigurable manufacturing system (RMS) is described as a sequence of events with discrete states and a state evolution, which occur according to the events that define the system state
The GPenSIM code is developed for simulation, performance comparison, and validation; the results show that the proposed method has accurate results and low-overhead computation compared with the studies in [1], [66]–[68]
Based on the operation routes and transportation requirements of the system and colored Petri net [1], the design of the colored resource-oriented Petri net (CROPN) is represented as follows: Consider an example of an automated manufacturing system presented in Figure 1(a) to demonstrate the formulation of a CROPN

Summary

INTRODUCTION

A reconfigurable manufacturing system (RMS) is described as a sequence of events with discrete states and a state evolution, which occur according to the events that define the system state. Chen et al [62] use an ROPN modeling approach to model the disjunctive and strict single-type automated manufacturing systems (DS-AMS) in which multiple units of one resource type are needed to support a processing stage They propose effective techniques to achieve the liveness of an ROPN of a DS-AMS by only enforcing some specific transitions to be controlled using its structural properties. A colored resource-oriented Petri net (CROPN) modeling approach is proposed for a rapid and valid reconfiguration of RMS, and necessary and sufficient conditions under which a maximally permissive control law is obtained to ensure the deadlock-free of RMS operations. Based on the operation routes and transportation requirements of the system and colored Petri net [1], the design of the CROPN is represented as follows: Consider an example of an automated manufacturing system presented in Figure 1(a) to demonstrate the formulation of a CROPN.

ADDING A NEW PRODUCT

COMPUTATIONAL COMPLEXITY Theorem 6

48. Output the LD graph LD

CONCLUSION