Development of a laser profilometer for the generation of 3d- models to measure the volume of fertilizer applied by fertilizer sowers

Laser profilometry based on triangulation is a method for measuring depth of points in space that uses a laser beam to scan the object. The image of a laser-line projected onto a surface of an object is captured and treated in image-analysis software, which calculates its profile. The union of a sequence of profiles allows the construction of the 3D-digital models of objects. The objective of this work was to develop a methodology and to build a prototype of a threedimensional scanner based on laser triangulation. A prototype was built, with a gantry structure containing a car on which are a laser diode and a camera. This car is driven by an endless shaft driven by an electric motor with variable speed. When moving the car, the laser module produces a line on the surface of the object that is filmed by a camera fixed at a known angle, obtaining the necessary information to generate the 3D model of the object. Tests were made on regular objects: hubcaps, pyramids and cobblestones and the results showed that the 3D-models produced had the same dimensions. Tests were also made on irregular objects such as soil surface and fruit. The prototype proved to be solid for generating 3D models of objects.