Quality-aware Co-Design of Responsive Real-Time Control Systems
Safety-critical control systems must comply with a specific quality of control. However, the relationship between real-time performance and quality of control is nontrivial. Typically, substantial overestimations, in particular of the worst-case execution times, have to be made to ensure compliance., The research objective of qronOS is the avoidance of pessimism in the design of hard real-time control systems and thus to abandon the trade-off between quality-of-control guarantees and good average performance. We pursue a co-design of control application and real-time executive that consists of the following three key aspects: model-based quality-of-control assessment, adaptive scheduling of control activities, and a hybrid execution model to regain guarantees.
When driving a car, a human pays full attention when required, but efficiently reduces the mental workload in less critical situations. On the other hand, current control strategies for autonomous cars always pay "full attention" and require precise timing. How can we make real-time control systems efficient and safe at the same time, just like a human can do it intuitively?
Timing plays a particularly important role in the solution for this problem: As control applications are particularly sensitive to timing variations, the Quality of Control (QoC) is degraded by varying execution conditions of the underlying real-time system. This is particularly relevant for modern, adaptive real-time systems, which introduce varying timing conditions for the sake of efficiency increases.
We aim to solve this design conflict by explicitly considering the relation between timing (Quality of Service, QoS) and the resulting Quality of Control both at design- and run-time.