Petri net-based design of modular supervisors for remotely human control systems

In an Internet-based control system, particular human operations may violate desired requirements and lead to destructive failure. For such human-in-the-loop systems, this paper extends the remote supervisory scheme by Lee and Hsu (2003) to a modular one so as to reduce the supervisor synthesis complexity. Also, remote human issued commands are guaranteed to meet required specifications. A rapid thermal process in semiconductor manufacturing systems is provided to show the practicability of the proposed approach.