On the advantages of combining differential algorithms and log-polar vision for detection of self-motion from a mobile robot

This paper describes the design and implementation on programmable hardware (FPGAs) of an algorithm for the detection of self-mobile objects as seen f rom a mobile robot. In this context, 'self-mobile' refers to those objects that change in the image plane due to their own movement, and not to the mo vement of the camera on board of the mobile robot. The method consists on a dapting the original algorithm from Chen and Nandhakumar [A simple scheme f or motion boundary detection, in: Proceedings of the IEEE International Con ference on Systems, Man and Cybernetics, 1994] by using foveal images obtai ned with a special camera whose optical axis points towards the direction o f advance. It is shown that the use of log-polar geometry simplifies the or iginal formulation and highly reduces the volume of data to be treated. Lim itations of the algorithm due to the differential nature of the approach ar e discussed, relating them with the parameters of the system. Experiments a re shown in which a self-mobile object is detected in several conditions. ( C) 2001 Elsevier Science B.V. All rights reserved.