Energy and Dependability Enhancement by Dynamic Actuator Derating in Cyber-Physical Systems

The energy consumption of the cyber part of cyber-physical systems (CPSs) has attracted considerable attention in recent years. Increased energy consumption results in increased thermal damage to the processors requiring more frequent replacements; and in many applications, it also requires increased energy storage capacity. Fault tolerance contributes to a large fraction of the cyber energy consumption in CPS since it is implemented using redundant computations.This paper studies the use of dynamic actuator derating (i.e., artificially limiting the maximum actuator output) for reducing the required redundancy. By targeting the use of fault-tolerance, we are able to obtain significant reductions in computer energy expenditure and thermal stress without lowering the reliability. This has beneficial effects on processor lifetime and required energy storage.