Omnidirectional Vision System Using Two Reflecting Mirrors

Abstract

Omnidirectional visual information is important to ensure the safety for the autonomous navigation of mobile robots. Usually such vision systems use a fish-eye lens or a reflecting mirror (spherical or hyperboloidal). The former system has a problem that unnecessary visual field occupies the most part of image. The latter one has also a problem that the camera image is blurred due to the physical property of the mirror curvature and thus the clear image cannot be obtained especially in a dark environment. In order to solve the above problems, we propose omnidirectional vision system using two reflecting mirrors with contrived curvature to obtain a panoramic image. Theoretical consideration is made to estimate the degree of aberration for the reflecting optical system that uses two mirrors with arbitrary curvatures, and a design method is developed to minimize the aberration of the image. The optical characteristics of a design example are evaluated and the results show the effectiveness of the proposed vision system.