Omnidirectional vision systems can provide images with a 360° of field of view. For this reason, they can be useful to robotic applications such as navigation, teleoperation and visual servoing. An effective way to construct this type of vision system is by combining lenses and mirrors together resulting on a system that does not require the movement of the camera to the direction of attention of the robot. A typical construction is by mounting a convex mirror in front of a camera aligning the center of the mirror with the optical axis of the camera. The most common convex mirror shapes used are conic, parabolic, hyperbolic and spherical. In this work we present two types of mirror that were constructed: a spherical mirror, used in the initial tests, and a hyperbolic, used for actual robot tasks. The hyperbolic mirror was manufactured using an ultra-precision CNC machine. Additionally, a software was developed to create panoramic and perspective images from the image acquired by the system. This work shows the development of an omnidirectional vision system, presenting the formulation used to determine a suitable mirror shape, the mechanical solutions used to build a fully operational system, and the results of the developed algorithm.
Vision system; hyperbolic mirror; mobile robot; image processing
