Improving the Rate Monotonic and the First Deadline First Schedulers for Real Time Simulation and Control of Aerospace Vehicles

Abstract

In this work we discuss and improve the rate monotonic scheduler and the first deadline first scheduler for real time simulation and control. These algorithms are largely know and discussed in the real time literature but in such literature: 1) some aspects of their original propositions are/remain incomplete or hidden; 2) there are even some counter-examples and critiques to them made in recent works. Correspondingly, in this work: 1) we discuss and clarify some aspects of their original propositions and we improve such propositions by explicitly writing down some of their incomplete or even hidden passages and transformations; 2) we also discuss and clarify some mistakes done in those counter-examples and critiques, by replacing them with new examples that confirm the algorithms and illustrate the points discussed, clarified, and improved. We also suggest some possible extensions of those algorithms and their uses in real time simulation and control of aerospace vehicles, especially aircrafts and satellites.