Joint WCET and Update Activity Minimization for Cyber-Physical Systems

Abstract

A cyber-physical system (CPS) is a desirable computing platform for many industrial and scientific applications, such as industrial process monitoring, environmental monitoring, chemical processes, and battlefield surveillance. The application of CPSs has two challenges: First, CPSs often include a number of sensor nodes. Update of preloaded code on remote sensor nodes powered by batteries is extremely energy consuming. The code update issue in the energy-sensitive CPS must be carefully considered. Second, CPSs are often real-time embedded systems with real-time properties. Worst-case execution time (WCET) is one of the most important metrics in real-time system design. Whereas existing works only consider one of these two challenges at a time, in this article, a compiler optimization—joint WCET and update-conscious compilation, or WUCC—is proposed to jointly consider WCET and code update for CPSs. The novelty of the proposed approach is that the WCET problem and code update problem are considered concurrently such that a balanced solution with minimal WCET and minimal code difference can be achieved. The experimental results show that the proposed technique can minimize WCET and code difference effectively.