Performance-Aware Power Management in Embedded Controllers with Multiple-Voltage Processors

Abstract

The goal of this work is to minimize the energy dissipation of embedded controllers without jeopardizing the quality of control (QoC). Taking advantage of the dynamic voltage scaling (DVS) technology, this paper develops a performance-aware power management scheme for embedded controllers with processors that allow multiple voltage levels. The periods of control tasks are adapted online with respect to the current QoC, thus facilitating additional energy reduction over standard DVS. To avoid the waste of CPU resources as a result of the discrete voltage levels, a resource reclaiming mechanism is employed to maximize the CPU utilization and also to improve the QoC. Simulations are conducted to evaluate the performance of the proposed scheme. Compared with the optimal standard DVS scheme, the proposed scheme is shown to be able to save remarkably more energy while maintaining comparable QoC. • h i : period, which equals the sampling period of the control loop i, with a nominal (initial) value of h i,0. • c i,nom : nominal execution time at full CPU speed, i.e. when α = 1. • c i : actual execution time when CPU speed is adapted, and it holds that c i = c i,nom /α.