Manufacturing at scale in a high mix environment with demanding ship schedules can be resource heavy and prove difficult to automate. The addition of just-in-time manufacturing principals further adds complexity and urgency at each process in the chain. A leading kitchen component manufacturer was struggling with precisely these issues and had not yet found a way to overcome its reliance on manual palletizing of its product range.
Orders being processed at the facility comprise of either stock requests from storefronts or customer driven parts lists that reflect the exact count and type of products that are needed to fully satisfy their home design. Adding more complexity to the product mix, the purchaser could select from a variety of configurations, colors, and surface finishes.
This meant that it was up to factory personnel at the end of the line to figure out how to position and stack product pallets and individually printing labels for each order set. Manually palletizing the orders proved time consuming and physically demanding as units could weigh up to 112lbs each.
The company knew that the palletizing process would benefit from automation, but with such a large number of products and even more possible order configurations, how could the system be flexible enough to accommodate the demands of such a diverse order set?
VMRA addressed the unique challenges of the manufacturer by designing the automation system in two zones. Zone 1 contained a KR 210 R3100 6-axis robot to handle the palletizing of products that enter the cell from two infeed conveyors. The design featured two possible pallet build locations to maintain a high robot utilization rate and keep up with desired cycle times.
Due to the unknown nature of products entering the cell and how they might need to be oriented to fit with others on a pallet, the robot would need to be capable of picking from the top or side of the product. This meant that using a 6-axis robot that could accommodate more complex moves instead of a traditional 4 or 5-axis palletizing robot was vital in enabling the system to position the product on the pallet with maximum precision and efficiency.
Custom software written by VMRA would be the key driver to the system's success by enabling the robot to determine what product would fit on which pallet and when to not pick product so that a pallet could be conveyed out of the operation area.
The software receives critical SKU dimension, weight, and orientation data from the factory MES system as the product is in transit towards the automation cell. The dimensional data is then be analyzed to determine a viable palletizing scenario that informs the robot's pick orientation as well as how to position or stack the product.
After a pallet is fully built it is conveyed into Zone 2. Safety light curtains separate the two zones to enable maintenance or changeovers to happen in one zone while the other zone could be fully operational in a manner safe to personnel.
The built pallet first encounters an in-line stretch wrapper that secures the load. Next it is conveyed to a labeling station where a printer that is tied to the MES system creates labels that reflect the order contents and store destination. The labels are picked by a KUKA KR12 R1810 robot and adhered to one of a handful of possible locations on the wrapped pallet. Since the pallet stacks are determined by order flow, the space claim of each pallet is highly variable and unknown to the robot. To resolve this VMRA custom designed an end-of-arm-tool that was outfitted with a 3D camera that images the wrapping to determine a suitably flat location. Placement was further secured through the use of a tool head with flexible compliance built into the design.
The pallet then exits the cell through an array of safety light curtains with muting sensors. The light curtain array will sense the size of the exiting pallet and mute only the light curtains necessary for it to exit the cell, leaving others engaged and thus providing complete worker protection during any operating conditions.
The dynamic palletizing system brought a variety of efficiencies to the end-of-line process. The speed and precision of the palletizing and labeling robots brought new output highs to the process. In the palletizing area, worker safety was improved by removing the laborious task of long hours being spent manually using an up-ender to rotate product and position them onto pallets.
The system also proved to be an asset in data integrity and order management. Receiving an order ticket, building the proper number of pallets, and printing labels had previously caused short orders or errors in the order mix. The new automated system received data from one source and had redundancies to confirm product flow, ultimately removing the opportunity for data issues.