Assessment of Petri nets Regulation Control methodologies for automation systems

Industry 4.0 and smart manufacturing bring new interesting possibilities and challenges, a particular one is the large-scale automation with minimal set-up time and flexibility. To face this challenge, control approaches based on Discrete Event Systems (DES), such as Supervisory Control Theory (SCT), Generalized Mutual Exclusions Constraints (GMEC) and Petri net-based Regulation Control (RC), may provide convenient solutions; however, few works have been reported in the literature describing the application of these approaches. In this work, the RC approach based on Petri nets is applied to three case studies: (1) an electro-pneumatic cell controlled by a Programming Logic Controller device (PLC); (2) a simulated hydraulic process controlled by a PLC (a virtual commissioning scheme); (3) a simulated robotic manufacturing cell controlled by a software tool. In addition, an assessment of the existing methodologies in RC for modelling, specification, control synthesis and control implementation is conducted. The findings of this work provide three contributions: (1) a practical validation of the applied methodologies and the identification of required extensions; (2) a discussion about the validity of frequently considered assumptions and hypotheses in DES; (3) a reference for practitioners on the implementation of the RC approach, as well as its limitations and advantages.