Real-time visuomotor update of an active binocular head

In order for a binocular head to perform optimal 3D tracking, it should be able to verge its cameras actively, while maintaining geometric calibration. In this work we introduce a calibration update procedure, which allows a robotic head to simultaneously fixate, track, and reconstruct a moving object in real-time. The update method is based on a mapping from motor-based to image-based estimates of the camera orientations, estimated in an offline stage. Following this, a fast online procedure is presented to update the calibration of an active binocular camera pair. The proposed approach is ideal for active vision applications because no image-processing is needed at runtime for the scope of calibrating the system or for maintaining the calibration parameters during camera vergence. We show that this homography-based technique allows an active binocular robot to fixate and track an object, whilst performing 3D reconstruction concurrently in real-time. Electronic supplementary material The online version of this article (doi:10.1007/s10514-012-9311-2) M. Sapienza ( ) Department of Systems and Control Engineering, University of Malta, Msida MSD 2080, Malta e-mail: [email protected] M. Hansard School of Electronic Engineering and Computer Science, Queen Mary, University of London, Mile End Road, London E1 4NS, UK e-mail: [email protected] R. Horaud INRIA Grenoble Rhône-Alpes, 655 Avenue de l’Europe, 38330 Montbonnot, France e-mail: [email protected]