Robot, feed thyself: Plugging in to unmodified electrical outlets by sensing emitted AC electric fields

We describe a robot that is able to autonomously plug itself in to standard, unmodified electrical outlets by sensing the 60Hz electric fields emitted from the outlet. The building electrical infrastructure is not modified in any way. Unlike previous powerline localization work, no additional signal is injected in the powerlines-the already present AC power carrier signal in the outlet is used as the localization beacon. This technique is faster, more accurate, and potentially less expensive than previously reported vision-based systems for autonomous plugging in.