  Electric vehicles (EVs) and plug-in hybrid vehicles (PHEVs) are rapidly
gaining popularity on our roads. Besides a comparatively high purchasing price,
the main two problems limiting their use are the short driving range and
inconvenient charging process. In this paper we address the following by
presenting an automatic robot-based charging station with 3D vision guidance
for plugging and unplugging the charger. First of all, the whole system concept
consisting of a 3D vision system, an UR10 robot and a charging station is
presented. Then we show the shape-based matching methods used to successfully
identify and get the exact pose of the charging port. The same approach is used
to calibrate the camera-robot system by using just known structure of the
connector plug and no additional markers. Finally, a three-step robot motion
planning procedure for plug-in is presented and functionality is demonstrated
in a series of successful experiments.
