This paper is concerned with an original procedure which has been designed to determine moving edges. An image sequence is considered as a 3D-space (x,y,t) and a moving local 2D-edge is modeled as a small planar patch in this 3D-space. A maximum likelihood procedure enables to simultaneously detect such planar patches and estimate their orientation (i.e., spatial direction of the corresponding 2D-edge element and perpendicular component of its displacement). The computational aspect of this method merely consists of convolution operations by considering appropriate local 3D-neighborhoods. This early processing is part of a robot vision algorithm for an obstacle avoidance task, currently developed at the laboratory.