Calibration-Free Visual Control Using Projective Invariance

Much of the previous work on hand-eye coordination has emphasized the reconstructive aspects of vision. Recently, techniques that avoid explicit reconstruction by placing visual feedback into a control loop have been developed. When properly deened, these methods lead to calibration insensitive hand-eye coordination. In this article, recent work on projective geometry as applied to vision is used to extend this paradigm in two ways. First, it is shown how results from projec-tive geometry can be used to perform online calibration. Second, results on projective invariance are used to deene setpoints for visual control that are independent of viewing location. These ideas are illustrated through a number of examples and have been tested on an implemented system.