From the cyber physical system to the digital twin: the process development for behaviour modelling of a cyber guided vehicle in M2M logic

This paper describes a research whose aim was to prototype a Digital Twin (DT) which meets the logistic behavior of a new family of automated guided vehicles (AGVs), based on the Cyber-Physical System (CPS) paradigm. The research consists of two steps. First, the implementation of CPS logic on an existing micro-controlled rover is examined; then, a traditional discrete event simulation (DES) software is used to simulate different environment application for the DT, including some modifications that allow identifying the most suitable solutions for the research aim. The specific design process has limited the stochastic variability of the simulated system to the mechanical component of the CPS-AGV. This because of the absolute identity of the logistic logic, operating both in the code used by the CPS-AGV micro-controller and in the code of simulating the system. The results show that the combined CPS-DT architecture allows a strategic optimization of the plant resources in Industry 4.0 configuration. To this end, different policy have been implemented to optimize the autoadaptive behavior of CPS-AGV, and each one of them has proven to be effective in a specific scenario. Outcomes of this study provide an industrial justification to the design and managing costs of Digital Twin implementation in an Industry 4.0 production system