January 09, 2013      

AUTOMATION WORLD.COM: Faced with the need to respond rapidly to an increasing diversity of product, packagers are demanding more flexible packaging machines.

OEMs and control system vendors are responding with systems that promise less – less complexity, less engineering and programming time, and less expense.

In terms of images, the robot almost defines modern automotive manufacturing. The iconic mechanical arm is the star of countless commercials designed to show that a particular auto company is ahead of the curve in terms of technology. Increasingly, that’s coming to be the case with packaging as well.

“Robotics is probably one of the fastest growing markets within the packaging industry today,” observes Leo Petrokonis, packaging industry business development manager for the global OEM team at Rockwell Automation, Milwaukee. “Robotic applications are increasing in number and expanding across applications, including picking and placing, and case packing.”

Surveys indicate the use of robots will be even more widespread in the future. Part of the reason for this is the ongoing improvement of the robot itself. “Compared to 10 to 15 years ago, robots are faster, more reliable and more affordable,” says Yarek Niedbala, directeur commercial, Kuka Robotics Canada Ltd., Mississauga, Ontario, Canada.

Few would disagree.

In fact, Dick Motley, account manager of North American Distribution for Fanuc Robotics America Inc., Rochester Hills, Mich., cranks it up a notch by saying that “today, reliability is almost a given.”

greenvale potato

It’s a point seemingly borne out by an application at Greenvale AP Ltd., in March, England, United Kingdom, one of Britain’s leading potato brands, has added robots to the packaging departments at its Cambridgeshire and Berwickshire plants. Each plant uses two Fanuc robots deployed in a packaging cell designed by Abar Automation, a Fanuc strategic partner in Hoofddorp, Netherlands.

Each of the two robots in the Abar DL-16 Loading Cell is tasked with picking 2.5 and 5 kg bags of potatoes and loading them into supermarket display containers at the rate of 60 bags per minute. The robots were originally designed to pick 30 bags per minute but, as Greenvale Operations Manager Rob Phillips explains, “the robots have been upgraded three times to accommodate increased demand.”

The Cambridgeshire plant now produces 2,400 metric tons of packaged potatoes each week, and the Berwickshire plant’s production has also increased. Along with the inherent flexibility that makes reconfiguring the packaging operation relatively simple, Phillips notes that the robotic cells also take up less floorspace than the previous approach.

“Best of all, though, the robots have been giving stable and reliable performance for the past year, requiring very little maintenance, and racking up an up-time rate of 99.98 percent, he says.

The degree of success that robots are having in packaging is a function of both brawn and brains. Robots are increasingly employed in data-intensive environments and they have been getting more “brainy,” so to speak, in order to operate in those environments. Case in point: Gilde.

glide_sausage

The Gilde warehouse and distribution center in Tonsberg, Norway, is a busy place. That’s because Gilde’s extensive line of meat products are highly popular with Norwegian consumers, and approximately 140 employees work at the facility getting freshly processed and packaged meat to customers.

For some time now they’ve had help: a Kuka KR 180 PA robot with a PC-based KR C2 control. The robot takes care of the “fast movers” – that is, the products that are ordered most frequently and in the highest quantities, often a seasonally adjusted category.

The process begins with a fork lift truck bringing pallets of crates, each containing large quantities of unmixed products, to the robot’s work area. The warehouse’s central computer informs the KR C2 control which products the robot should pick and in what order. The robot checks for itself whether it has grasped the correct product by holding the crate against a scanner. A new code is then generated and stuck onto the crate to specify the customer for delivery. The robot then places the crate on a conveyor, which transfers it to the next stage.

This unusual degree of flexibility in robotic order picking is mirrored by the flexibility with which the robot handles the crates. The KR 180 PA is able to handle even those crates presented in a non-uniform manner thanks to an ultrasonic sensor system in its gripper.

This monitors distances and allows the robot to be guided at the fastest possible speed to the first pick position. Once it has reached the crate, the gripper initially remains loosely closed until it has found the ideal gripping position. Only then does it tighten its grip. All of this takes more computational power than could be supplied by yesterday’s robot controls, but the KR 180 PA’s PC-based control is up to the task.

It’s worth noting here that Harvard University’s BioRobotics Laboratory is working on embedded sensing and actuation elements. They are seeking to do this through Shape Deposition Manufacturing (SDM), which alternates material deposition and machining to produce the complex, multilayered structures.

Among the possibilities being explored by the lab is a basic two-fingered gripper equipped with some or all of the following: Hall-effect sensors for joint angle sensing, embedded strain gauges for 3-axis force measurements, optical reflectance sensors for tactile sensing, and piezoelectric polymers for contact detection. The lab claims the parts created so far are extremely robust and able to withstand high impact loads and other forces.