Real-Time Scheduling of Energy Harvesting Embedded Systems with Timed Automata

In this paper, we propose feasibility and schedulability tests for a real-time scheduling problem under energy constraints. We first introduce the problem and show how to model it using timed automata. We then propose a feasibility test based on CTL model checking and schedulability tests for EDF and Preemptive Fixed Priority algorithms (PFP). Our approach also permits to generate a feasible schedule if one exists or otherwise to find how to correct battery characteristics to make the problem feasible. It is finally possible to generate schedules that optimize some criteria, such as the number of context switches between the battery recharging and discharging modes, the minimal and the maximal energy levels reached during the execution, or the number of preemptions. The approach is illustrated by some experiments using the model checking tool UPAAL [1].