In ADMORPH, we look at the guarantees that we can provide for embedded systems that do not behave as we expect them to do. One of this unexpected behaviour manifests itself as deadline misses. In particular, control tasks that miss their deadlines can be dangerous and potentially create trouble (think about the controller that prompts a car to hold a lane not computing regularly – the car could then deviate and cross to another lane, with potential for accidents).
Some of our research focuses on designing controllers that do not miss their deadlines, but in somecases we wonder what we can guarantee when we have a controller that might just misbehave occasionally. In a paper (co-authored by Paolo Pazzaglia, Arne Hamann, Dirk Ziegenbein and Martina Maggio) that will be presented next week at the Design, Automation and Test in Europe Conference (and won the paper award in the embedded and cyber-physical systems track – Thanks! We are really humbled and excited!) we look at how to modify existing controllers in a viable way.
When a controller is already in production phase, only small modifications will be allowed (changing some constants here and there)but this can potentially go a long way to enforce some robustness. In the paper we describe one of such small modifications to an existing control architecture and implementation and show that using the knowledge of past misses can improve the controller performance.