Cardboard boxes of different sizes on conveyor belt in distribution warehouse
Introduction
Warehouses and distribution centers have been using OCR scanners (2D scanners) for sorting boxes into different stacks according to the shipping labels. However, warehouse management soon realized that simply scanning the label is insufficient. Time and time again, the robotic palletizer would pick up boxes that are damaged, have open flaps or have wrong dimensions and place them onto the pallet. These boxes would disrupt the packing pattern and sometimes causing damage to the goods.
The warehouse needs a 3D scanning solution where the dimensions of the box can be accurately measured and sorted out of the line if there were any irregularities. Simply put, they needed the robotic palletizers to “see” what they were handling.
System Requirements
The sorting system has to accommodate the boxes of varying shapes and sizes and issue a trigger when any of the parameters is not met. The parameters are to pick out boxes with open flaps, bulging contents or wrong dimensions. Based on the trigger signal, the box is diverted to another conveyor belt, where operators can repackage it. The scanner must be efficient enough to process a minimum of 150 boxes per minute for the fast-moving distribution center.
System Description
In this application, the SL-1880 fully-integrated 3D scanner is used for the box sorting system to verify critical features on each box. The 3D image is used to verify the dimensions of each box by building a three-dimensional model and then detecting boxes with open flaps or other irregularities as each box passes. The box is sorted accordingly, and the next box enters the system. If one or more of the parameters are incorrect, then a reject code is generated, and the box is separated out of the line.
Conclusion
With reliable 3D machine vision in place, the box sorting system achieves a sorting accuracy of 99.9% with the capability of operating at 150 boxes per minute. The newly improved process means the sortation needs less human supervision, and the warehouse can meet the demand for timely delivery with confidence.
“The 3D vision system has been installed for a while, and the manufacturer considers his in-line box sorting systems a competitive advantage.”
Concept Systems