Visual recognition of a door and its knob for a humanoid robot

This paper deals with the practical problem of how a humanoid robot recognizes a door and its knob in an office environment. This is the initial work where a humanoid robot recognizes, approaches, and opens a door. We propose an integrated solution for visual recognition of a door and its knob with minor constraints. In our approach, the door recognition is transformed into the classification problem of feature points, which can be done quickly enough to conduct it on-line. The knob is extracted by a segmentation method and a few thresholds: blob size, blob ratio, and the distance from the floor. We show in the experiment that our humanoid robot can recognize a door and its knob reliably and quickly.