Abstract
In this article, we propose a technique for automatic contactless measurements of three-dimensional coordinates of surface points in a granary. The need for an automatic measurement and registration of surface points arises when conducting accurate measurements of the volume of bulk materials during stock-taking of raw materials and finished goods. A peculiarity of the technique consists in obtaining and recognizing the surface images in which the sought-for points are highlighted by laser light. The recognition process is closely related to camera specifications and a specific arrangement of laser diodes. The problems considered include the determination of parameters and location of the recording cameras, and the number and layout of the laser diodes, the implementation of 3D measurements from a set of images, and the selection of storage procedures for the measurement results. As a result of the experiments, it was proved that the proposed solution, which exploits the capabilities of photogrammetry and laser scanning methods, has a number of advantages over the existing methods in terms of efficiency, accuracy, the possibility of automation, the opportunity of monitoring the surface of the granary content at any time, and the possibility of remote tracking. Computerization of the described methods allows one not only to perform single volume measurements, but also to carry out a regular contactless monitoring of complex surfaces in locked warehouses for making managerial decisions.