Planar Passive Navigation: One Dimension Is Better Than Two

TitlePlanar Passive Navigation: One Dimension Is Better Than Two
Publication TypeTechnical Report
Year of Publication1992
AuthorsDe Micheli, E., & Verri A.
Other Numbers763

This paper is based on the observation that if a viewing camera is appropriately mounted on a vehicle which moves on a planar surface, i.e. the image plane of the camera is orthogonal to the planar surface and the optical axis parallel to the instantaneous direction of translation, then the angular velocity is the only motion parameter to be computed. Consequently, the problem of motion and structure recovery from optical flow becomes linear and, in principle, can be solved locally. Elementary error analysis shows that the angular velocity can be robustly estimated by averaging the horizontal component of the optical flow along the vertical line through the center of the image. Once the angular velocity has been recovered, depth can be computed from one component only of the optical flow. It is shown that the accuracy in the estimation of depth from the vertical component is more accurate, increases with the distance from the horizontal line through the center of the image, and is almost independent of the angular velocity. From the reported experiments on synthetic data and real images it can be concluded that in applications like autonomous robot navigation the computation of the two-dimensional (2D) optical flow over the entire 2D image plane can be probably avoided.

Bibliographic Notes

ICSI Technical Report TR-92-058

Abbreviated Authors

E. De Micheli and A. Verri

ICSI Publication Type

Technical Report