The geometric characterization of mouldboard plough surfaces by using splines

摘要: Abstract For historic reasons, mouldboard ploughs have a wide variety of surfaces. The concentration manufacturers has reduced the number different types but there are still few complete geometric descriptions surfaces plough. With aim describing and characterizing three-dimensional shape plough, permitting obtaining tool for an adequate preparation soil cultivation, as well reducing labour costs, in this work approximation methods been explored. results obtained allow us to conclude that application non uniform rational B-splines, combined with optimization algorithm based on assigning weights control points surface analyzed, is method which succeeds improving quality fit respect other algorithms proposed by several authors previous works also use splines. root mean square error these plough was lowest 1.9 mm observed, increases up 14.4 mm using simple Bezier bicubic parametric surface. Using efficiency index Nash Sutclife (1970), highest value, 0.995, corresponded B-splines method.