Inspection System for Automatic Measurement of Level Differences in Belt Conveyors Using Inertial Measurement Unit

Belt conveyors are transport systems composed by a plurality of belt lines. When those systems are used to transport fragile materials or liquid containers, it is necessary to minimize the oscillations of the transported objects in order to avoid damage, spillage and particle degradation. Those oscillations are regularly caused by steps (i.e. differences in level) at the joints of the belt lines, and for that reason, it is necessary to inspect those steps during installation and maintenance. Regular inspections involve the visual verification of the steps, which stops production, takes significant time, occasionally requires system disassembly and is subjected to human errors. In this paper, a novel belt conveyor inspection system which is able to detect and measure the steps at the joints of the belt lines is presented. This system consists in the acquirement of data of the belt conveyor with an inertial measurement unit (IMU), and the processing of this data with original algorithms for zero offset filtering, sensor progressing direction detection, step event detection and step height calculation. The presented system had successfully detected and measured the steps of a complex belt conveyor with an accuracy of $\pm 0.3\ \text{mm}$ . It is demonstrated that this cost-effective and ready to use system enables an automatic and prompt inspection of the whole belt conveyor system at once, thus reducing the workload, time and errors of the belt conveyor inspection.