Fault Handling in Discrete Event Systems Applied to IEC 61499
Herbert Albérico de Sá Leitão, Roberto Rosso, André B. Leal, Alois Zoitl
Abstract
The search for making industrial systems smarter is a challenge present in the Industry 4.0 scope. In this new industrial era, the automation processes operate in a more flexible and adaptable way, even if there is a system fault. However, depending on the level of complexity of the system operation, faut diagnosis and fault handling procedures can become difficult to evaluate and implement, especially when it is necessary to integrate them into the control system. Based on this challenging scenario, this article presents RAFAH, a reconfiguration architecture for fault handling in industrial systems. RAFAH is composed by three operational stages that autonomously compute flexible fault tolerant control strategies, combining formal methods for faults diagnosis in discrete event systems, supervisory control theory's extensions for modelling and designing control systems, and IEC 61499 resources for developing distributable and reconfigurable applications. The proposed methodology is validated by a case study in a fluid mixing process in which it is applied to diagnose faults and provide a new control strategy.