Multiple cranes control with task deadlines and priority constraints

In this paper, we solve a multiple cranes scheduling problem; cranes sharing the same track are considered. Cranes can reach any location along the track performing loading or unloading operations. As cranes share the same track their movements are constrained to avoid over crossing; task deadlines and priorities are also considered. We propose a control oriented approach to this class of problems. We modeled crane movements with Petri Nets, obtaining a binary model. We then considered task constraints and formulated the general scheduling problem when the control objective is to minimize the total amount of time to accomplish the task list. Computational experiments show that our approach could be used as an on line scheduling in a working plant.