Filtre recursif nonlineaire [Nonlinear recursive filter]

Un filtre récursif nonlinéaire est synthétisé de fa?on simple par utilisation de la transformée de Laguerre multivariable et d'un isomorphisme entre l'espace des signaux continus et l'espace des signaux discrets. A nonlinear recursive filter is easily synthesised by use of the multidimensional Laguerre transform and of an isomorphism between the continuous-signals space and the discrete-signals space.     

Detection and three-dimensional localization by stereoscopic visual sensor and its application to a robot for picking asparagus

This paper describes a three-dimensional localization process used on an agricultural robot designed to pick white asparagus. The system uses two cameras (CCD and Newvicon).Thanks to diascopic lighting, the images can easily be binarized. The threshold of digitalization is determined automatically by the system. A statistical study of the different shapes of asparagus tips allowed us to determine certain discriminating parameters to detect the tips as they appear on the silhouette of the mound of earth.The localization is done stereometrically with two cameras. As the robot carrying the system moves, the images are altered and decision criteria modified. A study of the images from mobile objects produced by both tube and CCD cameras was carried out. A simulation of this phenomenon has been done to determine the modifications concerning object shapes, thresholding levels and decision parameters as a function of robot speed.     

Fast inversion of triangular Toeplitz matrices

An algorithm requiring0(n log n)operations is proposed for the inversion of triangular Toeplitz matrices. This algorithm is faster than existing techniques, even for relatively small values ofn, and can easily be written in Fortran.