Synthesis and Implementation of Distributed Supervisory Controllers With Communication Delays

• Published in: IEEE transactions on automation science and engineering Vol. 20; no. 3; pp. 1 - 16
• Main Authors: Moormann, Lars, Schouten, Reinier H. J., Mortel-Fronczak, Joanna M. van de, Fokkink, Wan J., Rooda, Jacobus E.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.07.2023; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Behavioral sciences; Communication; communication delays; Computational modeling; Control systems; controller distribution; Controllers; Delays; hardware-in-the-loop; Localization method; Mechanical engineering; mutual exclusion; Real time; road tunnels; Roads; Robust control; Supervisor synthesis; Supervisors; Supervisory control; Synthesis
• ISSN: 1545-5955; 1558-3783
• DOI: 10.1109/TASE.2023.3260442

This paper discusses a method to distribute a synthesized supervisor for implementation on multiple physical controllers. Dependency structure matrices are used to determine a distribution of a system. The supervisor is then distributed accordingly, using an existing localization method. Communication delays between the distributed components of a supervisor may affect its behavior, due to changes in the order of events. Therefore, a new delay-robustness check is proposed and where needed mutex locks are employed to make the distributed supervisor delay robust. The controller performance is analyzed and optimized through a parameter study and a mutex implementation evaluation. In a real-life case study, the method is demonstrated by synthesizing, distributing, implementing, and validating a supervisor for a road tunnel. Note to Practitioners -This article is motivated by the desire to bridge the gap between the asynchronous, discrete-event, world of synthesized supervisors and the synchronous, real-time, world of networked PLC controllers. The main focus lies on maintaining the guarantees of supervisor synthesis while taking into account all aspects of real-time implementation, such as cycle-driven code execution and communication delays.