Robotics: Take a hands-off approach
Robotic piece picking
While mobile robotic solutions deliver product in a goods-to-person operation, stationary robots are able to receive product for piece picking operations.
In one example of a “goods-to-robot” solution, a spider style robot can perform extremely rapid pick and place function, sometimes as fast as 2,400 pieces per hour. According to Ross Halket, Schaefer Systems’ director of automated systems, this technology has been around for years, but the difference now is the advanced software that controls the sequencing and the vision technology that enables accuracy in the pick.
“The first critical part of the process is to drive the SKU in the right speed and the right sequence to the robot cell so it has what it needs when it needs it,” says Halket. “The second critical step is for the robot to see that it’s picking the right SKU.”
In this case, product is delivered to the robotic picking system in totes from an automated storage system. A laser identifier recognizes the product, its position in the tray, and the optimal center of gravity for picking. Then, the vision technology confirms and processes the information, then makes a picking decision. The robot’s end effector lifts the product from the tray and drops into an order tote or picking buffer.
This is a good e-commerce solution, says Halket, especially for retailers that faced challenges getting into that end of the business because their original systems weren’t designed for small orders. For these robots, shapes and sizes don’t matter; it’s the weight that determines what’s pickable. If an end user is handling products at both ends of the scale, another picking cell can be added to lift heavier items with a different end effector.
In a different approach to picking, an articulated arm robot, which is programmed to know the cubic characteristics of each item, directs its robotic arm to grip the selected product, lift it and strategically place it into the order container or shipping carton. These types of robots are able to perform about 450 picks and defined placements in an hour.
In this application, product is “smartly” placed into the shipping container so it doesn’t have to be manually adjusted further down in the picking process, explains Bill Ostermeyer, vice president of sales for viastore. Because the system is programmed with sizes and dimensions of product and containers, the robot can strategically place an item into a container, making the best use of the available space.
While these spider and articulated arm robotic picking solutions vary in application and speed, they have common features. Both robots are fully automated solutions that are integrated with automated storage systems that provide a constant supply of product. Additionally, both approaches can support a multi-order process, which means they can pick different orders from one container.
Another common denominator is end-of-arm tooling, also known as end effectors. These devices have sensors that enable the robot to locate products—and hardware like vacuums or gripping clamps to lift it.
Like a power drill with changeable bits, similarly you can take off one end effector type and attach another, says Dematic’s Ruehrdanz, depending on the product being handled and the gripping strength needed. For example, cartons of lightweight, fragile light bulbs require a different gripping strength than books. Or, end effectors that handle rigid cartons would be different than those handling products packaged in bags.
Once orders are filled and product is packed into shipping containers, they have to be palletized for shipping out to customers—and robots can also have a hand in the palletizing process.
Simply building a pallet isn’t enough. “The basis of everything is building a pallet as close to store ready as possible,” says Brian Duncan, executive account manager at Schaefer Systems.
The challenge in building store-ready pallets is that robot solutions have to recognize the various sizes and dimensions of multiple SKUs and understand the various customer stacking rules, says Brian Keiger, logistics account manager for Kuka Systems.
One way to build a store-ready pallet that addresses the customer’s staking rules is with a pack pattern generator software tool that builds a virtual pallet before the robot touches or moves anything. The system plans the sequencing of product upfront using a number of regulators like weight and crushability, for example. When the optimal pallet is planned, then product is sequenced to the robotic palletizer.
Gantry robots are one type of solution being used in the warehouse for palletizing. A gantry robot is a bridge-like structure that moves horizontally on overhead tracks that can span large areas. The gantry’s end effector lifts and transports product to its target conveyor for palletizing.
Overall, robotic case and layer picking applications are gaining traction across many industries, says Derek Rickard, distribution systems manager at RMT Robotics. “It doesn’t matter to the equipment what the SKU is, what matters is the size, weight and shape of the product. Pallet building is all about geometry. The commonality of packages lets you build pallets, and the combination of clamping tools and vacuum technology lets us pick up virtually anything.”
In addition to picking up and palletizing all types of items, robotic palletizers can do it faster and more efficiently than people. Not only can robots build about 700 pallets per hour, they build them 35% denser than manually built pallets, which packs out trucks better, saves on freight and results in less damage, loss and worker injury.
Robots down the road
Once operations had a choice between people and fixed materials handling solutions to move product; today, new robotic technology is giving end users more flexible options.
“People are good at working through problems, but not as good at highly repetitive tasks; robotics are good at repetitive tasks, but not as good at solving problems,” says Motoman’s DeRosett.
As a result, he envisions a future in which people and robots work side by side. “It’s exciting to look at a robot as an assistant to a person. We’re not there yet, but given enough time and resources we’ll get there—as long as we have real problems that need to be solved.”
The robots are coming
Robotic materials handling technology is changing the way we move products in the plant and the distribution center.