Robust co-design of control and real-time scheduling in cyber-physical systems

Abstract

Cyber-physical systems (CPS) have emerged as a promising research paradigm, which is the convergence of control, communication, and computation. In CPS, real-time transactions visit multiple resources such as sensors, actuators, networks, and microprocessors. One fundamental issue, which is called control and real-time scheduling co-design, is how to maximize control performance of the physical systems while satisfying the real-time constraints imposed by limited computational resources. Although there have been extensive studies on the co-design problem in a single-resource system, multi-resource cases have not been fully studied. In this paper, we propose an optimization framework for robust control design with end-to-end response time constraints in a multi-resource system. We introduce a rigorous robust performance metric from the control theoretic viewpoint. Then, we investigate the impact of end-to-end response time analysis techniques on the control performance. We show that the traditional per-job response time analysis significantly degrades the control performance when real-time tasks visit a resource multiple times. We demonstrate that we can improve the control performance by adopting the per-resource response time analysis. Our simulation results verify the effectiveness of the proposed co-design framework. © 2016 NSP Natural Sciences Publishing Cor.