SolarTune: Real-time scheduling with load tuning for solar energy powered multicore systems

In this paper, we target at the direct-coupled solar energy powered multicore architectures that provide direct power supply between photovoltaic (PV) generation and the load without the adoption of battery. We present Solar-Tune, a real-time scheduling technique with load tuning for sporadic tasks on solar energy powered multicore systems. The objective is to fully utilize the available solar energy while meeting the deadlines of tasks. To solve the problem, we first perform analysis and formulate the scheduling problem in each duration as an integer linear programming (ILP) model to obtain an optimal schedule. Then we present a heuristic algorithm to dynamically refine the task scheduling based on the predictions of the availability of solar energy. We conduct experiments using real-world meteorological data across different geographic sites. The experimental results show that SolarTune can significantly improve the solar energy utilization ratio and reduce the number of deadline misses compared to the conventional task scheduler.