caa a22 4500 467915059 CHVBK 20180406152859.0 cr unu---uuuuu 170328e20060701xx s 000 0 eng 10.1007/s11263-005-5032-8 doi (NATIONALLICENCE)springer-10.1007/s11263-005-5032-8 Automated Alignment of Robotic Pan-Tilt Camera Units Using Vision [Elektronische Daten] [Joss Knight, Ian Reid] In this paper we show how to carry out an automatic alignment of a pan-tilt camera platform with its natural coordinate frame, using only images obtained from the cameras during controlled motion of the unit. An active camera in aligned orientation represents the zero position for each axis, and allows axis odometry to be referred to a fixed reference frame; such referral is otherwise only possible using mechanical means, such as end-stops, which cannot take account of the unknown relationship between the camera coordinate frame and its mounting. The algorithms presented involve the calculation of two-view transformations (homographies or epipolar geometry) between pairs of images related by controlled rotation about individual head axes. From these relationships, which can be calculated linearly or optimised iteratively, an invariant line to the motion can be extracted which represents an aligned viewing direction. We present methods for general and degenerate motion (translating or non-translating), and general and degenerate scenes (non-planar and planar, but otherwise unknown), which do not require knowledge of the camera calibration, and are resistant to lens distortion non-linearity.Detailed experimentation in simulation, and in real scenes, demonstrate the speed, accuracy, and robustness of the methods, with the advantages of applicability to a wide range circumstances and no need to involve calibration objects or complex motions. Accuracy of within half a degree can be achieved with a single motion, and we also show how to improve on this by incorporating images from further motions, using a natural extension of the basic algorithm. Springer Science + Business Media, LLC, 2006 alignment nationallicence active vision nationallicence calibration nationallicence Knight Joss Active Vision Lab, Robotics Research Group, Department of Engineering Science, University of Oxford, Parks Road, OX1 3PJ, Oxford, UK aut Reid Ian Active Vision Lab, Robotics Research Group, Department of Engineering Science, University of Oxford, Parks Road, OX1 3PJ, Oxford, UK aut International Journal of Computer Vision Kluwer Academic Publishers 68/3(2006-07-01), 219-237 0920-5691 68:3<219 2006 68 11263 https://doi.org/10.1007/s11263-005-5032-8 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11263-005-5032-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Knight Joss Active Vision Lab, Robotics Research Group, Department of Engineering Science, University of Oxford, Parks Road, OX1 3PJ, Oxford, UK aut NATIONALLICENCE 700 1- Reid Ian Active Vision Lab, Robotics Research Group, Department of Engineering Science, University of Oxford, Parks Road, OX1 3PJ, Oxford, UK aut NATIONALLICENCE 773 0- International Journal of Computer Vision Kluwer Academic Publishers 68/3(2006-07-01), 219-237 0920-5691 68:3<219 2006 68 11263 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer