Person Tracking with a Mobile Robot using Two Uncalibrated Independently Moving Cameras

This paper presents an efficient person tracking algorithm for a vision-based mobile robot using two independently moving cameras each of which is mounted on its own pan/tilt unit. Without calibrating these cameras, the goal of our proposed method is to estimate the distance to a target appearing in the image sequences captured by the cameras. The main contributions of our approach include: 1) establishing the correspondence between the control inputs to the pan/tilt units and the pixel displacement in the image plane without using the intrinsic parameters of the cameras; and 2) derivation of the distance information from the correspondence between the centers of masses of the segmented color-blobs from the left and the right images without stereo camera calibration. Our proposed approach has been successfully tested on a mobile robot for the task of person following in real environments.