Sorting system for wooden pallets.

UAB Robotex – Today’s consumer demands require the highest quality products manufactured under production at the lowest possible cost. “ROBOTEX” mainly specializes and excels in providing automation solution for IKEA supply chain companies mainly in furniture industry. Also specializes in wooden pallet industry solutions and palletizing of bags, boxes and other type of packed products.

The wooden pallet is the most widely used reusable flat transport structure in all logistics sector. Wooden pallets are susceptible to environmental and handling wear and tear factors. To be reused they have to re-evaluated for quality, sorted and repaired or scraped. They are usually transported in stacks (15-20 pallet) up to 3-meter height. The handling and quality decision making is usually done by human hand.

The handling and quality decision making is usually done by human hand, so following problems are daily :

• It is very hard and monotonous work
• The decision quality varies greatly depending on human factors (fatigue, personal preference, lighting conditions and etc.)
• The human mistake in sorting quality is costly both ways, false-negative and false positive, there are losses of value inside the company with each mistake
• A need to remove and isolate human factor and variation of decision making to have a stable and reliable process

Robotex has designed the system which uses visual and 3d sensors to scan the pallet stack, evaluate the top pallet position, grip the pallet in the correct angle, manipulate the pallet in front of sensors to make additional scans, evaluate the defects and categorize the sort of pallet according the level of ware and tear, color, type and other factors and stack them in separate stacks.

Operator and system decision matches 85.1%

Robot identify as bad pallet due to foreign object (carton, stretch wrap) 1.4%

Robot mistake – good pallet identified as bad 0.3%

Robot mistake – bad pallet identified as good 0.5%

Operator mistake – good pallet identified as bad 3.0%

Operator mistake – bad pallet identified as good 6.9%

Marginal situation (both can be considered right) 2.8%

Average human error rate 9.8%

Average robotic system error rate 2.3%

Smart sorting system is an all-in one robotic solution ready to be installed and consist of following main components:

• The robot arm (industry standard) – that picks the pallets from the stack, presents it for scanning in needed angles and stacks according the system decision.
• The vision system with RGB, Infrared and 3D depth sensors.
• Processing computer with specialized software for real-time defect analysis.

Most pallet sorting is currently performed at the stack level, i.e. not all pallets are checked, but the “roughly” well-looking stack is sent back to the producers for further use, and the “roughly” evaluated stack of defective pallets is sent to a service provider for pallets repair, where it additionally has pallets to be sorted.

The automatic pallet defect identification and sorting system will allow the pallets to be sorted by quality in the pallet assembly, provide good quality pallets to manufacturers, and defective pallet repair providers, thereby preventing damage to the product due to improper handling of the pallet.

In addition, because of the inadequate sorting of pallets, their demand on the market is artificially increased, as many good-quality pallets, instead of being immediately employed, travel to the repairer, and the manufacturer, knowing that the percentage of defective pallets is significant, commission and use more pallets than him really needed. The automatic pallet defect identification and sorting system will help optimize the pallet industry and reduce the need for new pallets, while reducing the use of wood for pallet production and, accordingly, protecting the environment.