Automated counting of palletized slate slabs based on machine vision

Slate manufacturing process is made up of different sub-processes required to obtain the commercial slate slabs. Sawing, splitting, shaping, quality control, counting and palletizing, are necessary to transform the slate block extracted from the mine. Most of these working stages include robust machines based on different industrial technologies, which allow the automation of the manufacturing process to obtain the commercial slate slabs. However, some working stages, like slate slabs counting, remain laborious and slow manual processes with low productivity, high subjectivity and a low level of reliability. The inherent non-repetitiveness in manual counting of slate slabs after manual checking and palletizing, requires the use of a new technology that allows the automation of palletized slate slabs counting which enable a fast and accurate processing. This paper presents the development and implementation of a 2D vision system for palletized slate slab counting, which allows overcoming the limitations of the manual counting solution which is currently used in industry. Experimental results obtained in an industrial machine prototype are shown, demonstrating the viability of the system. The proposed solution based on 2D vision system, can be applied to count different slate slabs geometries in actual manufacturing conditions with variable lighting conditions.