Low cost contour check of loading units using PMD sensors

In this paper, a novel approach for the detection of parcel loading positions on a pallet is presented. This approach realizes a substantial change in comparison to traditional system design of contour detection in de-palletizing processes. Complex 3D-vision systems, costly laser scanners or throughput decreasing local sensor solutions integrated in grippers are substituted by a low-cost Photonic Mixing Device (PMD) camera. By combining PMD technology and a predetermined model of loading situations, stored during the assembly of the pallet, this approach can compensate for the drawbacks of each respective system. An essential part of the approach are computer-graphics methods specific to the given problem to both detect the deviation between the nominal and the actual loading position and if necessary an automated correction of the packaging scheme. From an economic point of view this approach can decrease the costs of mandatory contour checking in automated de-palletizing processes.