method and apparatus for estimating the projection on a plane of reference of the direction of development of fibers of a portion of a wooden plank

摘要

A method for estimating the projection on a reference plane (XZ) perpendicular to a first face (2) of a plank (1), of the direction of extension of the fibres (L) comprising the steps of: emitting a first and a second polarized microwave beam towards the plank (1) according to a first and second directions of incidence lying in a first and second plane (P±), (P²) which form a first and second minimum angle (±1), (²1) with said first face (2) which are not less than 30° and which intersect the first face (2) along a first and second lines transversal to the nominal direction of the fibres (N); the second plane (P²) also forming with the first plane (P±) a third minimum angle (±²) which is not less than 30°; detecting the residual part of the first and second beam which passed through the plank (1); determining amplitude and phase corresponding to those of the residual parts detected; and estimating the orientation of said projection by processing the amplitudes and phases previously determined. It is also claimed a device operating such a method.