In: Proceedings of the second IEEE International Conference on Systems, Man and Cybernetics (SMC'02), October 6-9, 2002, Hammamet, Tunisia, Volume 2. IEEE Computer Society Press, October 2002.
Abstract: The presented works focus on the scheduling of electroplating lines, known as the "hoist scheduling problem". Scheduling problems are usually np-hard. Consequently, it seems better to keep the same schedule as long as possible. Robustness properties are also needed for the sequence of the operations, whereas most of the time, the local control can be computed on-line. In this paper, the concepts of robust control with regard to time constraints will be explained. Then p-time Petri nets are used at every step of the control synthesis: modeling time constraints, conveyor sequencing, and robustness analysis. The main contribution is the proof of external dynamic robustness of the control.