Technology / Packaging

Robots: Not Just for the End of the Packaging Line

As packaging robots get more sophisticated and safer for humans, their potential applications increase.

By Pan Demetrakakes, Senior Editor

Robots will never be “human,” but they’re developing like humans. Specifically, kindergarteners: They’re improving their mobility and hand-eye coordination, learning more quickly and starting to work well with others.

All of those things are making robots more useful on packaging lines.

The most common location for robots on a packaging line is at the end, especially palletizing. But as robots become smaller, faster, cheaper and more versatile, their potential uses in packaging are extending farther up the line.

Perhaps the most compelling adjective in that list is “cheaper.” Robots used to be an expensive, exotic, futuristic innovation; now they’re becoming close to an off-the-shelf commodity.

“In the past, robots were expensive, relatively slow, not particularly flexible,” says packaging automation consultant John Henry. “That is in the past.”

He notes that, for example, that an off-the-shelf robot with a mounted filling mechanism can be purchased for $75,000 and be ready for action in a few weeks; a comparable dedicated machine might cost $200,000 and take months to deliver. A robot with vision system, plus conveyors and integration, would probably cost $40,000 to $50,000; a comparable non-robotic packaging machine might cost two to three times that much, he says.

The vision systems that work with packaging robots are another important development. They have become more sophisticated, able to process images faster and with greater detail. “Vision is what really makes robots useful,” Henry says.

Improvements extend to both the hardware that captures images and the software that evaluates them, says Bob Doyle, vice president of the Robotic Industries Assn. 

“There’s definitely been improvement in the vision system itself as well as the software, [with] the use of machine learning technology for the vision system with the robot to make better decisions using the data to pick the product or the piece,” he says.

These improvements allow robots to move beyond simply being able to pluck objects from a predetermined location and orientation. Not only can they now see objects that are scattered randomly on a belt; with the advent of three-dimensional vision, the objects no longer need to be on a belt at all.

“3D lets the robot pick bottles that are jumbled in a bin in any orientation and orient them correctly,” Henry says. “Add pattern recognition and it can pick the bananas out of a mixed bin of apples, oranges and bananas.”

Sophisticated vision systems also help robots perform quality control functions along with material handling, Doyle says. Items that don’t meet quality standards, such as blemished or misshapen produce, can be diverted.

Getting along with humans

Putting robots farther up the packaging line, or anywhere else, won’t work unless they can work as harmoniously as possible alongside human workers.

The standard way of dealing with robots is to literally cage them. Putting a protective metal grid around the robot, big enough to encompass the radius of its arm, is the easiest and most reliable way to make sure the arm doesn’t hit anyone as it swings around. But doing so doubles, or more, the robot’s footprint, rendering valuable space unproductive. It also makes it impossible for robots and humans to work in proximity.

“A typical industrial robot is going to be operating behind a cage of some sort that protects people from it,” says Greg Selke, CEO of ONExia, a distributor and integrator of robotic systems.

“Industrial robots are pretty strong, they have no idea that anyone is in the area around them, and they could certainly hurt or even kill a person.”

A “cobot,” or collaborative robot, eliminates that danger with inherent safeguards that remove the need for a barrier perimeter. They’re programmed to stop whenever their arms encounter the slightest obstruction, and they’re often equipped with proximity sensors that slow them down whenever someone gets too close.

Olympus Controls, a supplier and integrator, supplies robots that can be programmed to run, for instance, at half-speed when someone gets with five feet, at 20 percent speed when someone gets within three feet, and to shut down if anyone is within one foot.

These safety measures allow robots to work literally side-by-side with humans.

“The person and the robot can work together potentially on the same task, and then when the person does its part it moves away, and the robot continues doing what it’s supposed to be doing,” Doyle says.

He emphasizes that cobots are an application, not a distinct type of robot, meaning that almost any kind of industrial robot can be made into a cobot with the proper programming and sensor technology.

Teaching the robot

Not only is it easier to work beside robots, it’s becoming easier to teach them. As with many forms of digital technology, programming is becoming more intuitive and less technical.

Many robots have a “teach pendant,” a tablet-like screen with a graphical user interface that allows personnel to program the robot step by step. Some robots, especially ones that have been configured as cobots, take that a step further: They can be programmed by being physically moved into each position they’re supposed to assume in a given process.

Selke says that Universal Robots, one of the manufacturers ONExia represents, makes robots that can be physically programmed in this manner. Floor workers can move it into a starting position and “show” it where it needs to stop, open its gripper, etc.

“The thing that we’re seeing is, it’s really allowed or has been attractive to smaller companies who have very little automation – certainly have no robots,” Selke says. “It’s allowed them an entry into beginning to automate some of their processes.”

Improvements in gripper technology, which have been going on for a while, are continuing to progress. This is partly a consequence of the expanded use of robots for all kinds of applications, especially agricultural. Grippers are being developed that can do things like twist strawberries off a stem without bruising them – applications that are now vital, with immigration crackdowns cutting into the pool of agricultural labor. This opens up the possibility of involving robots in handling primary packages, or even unpackaged products, directly, allowing them to move up the packaging line.

“We are seeing those robotic applications move upward within the lines, whether that is picking the actual food product,” Doyle says. “We’ve seen advances in technology, especially gripping technology, that are allowing a soft-type gripper that can pick a food product, whether it be a ball of dough or a head of lettuce or a tomato, that allows it to be picked off a line.”

On the move

Another development with packaging robots is mobility. As robots can be moved, or move themselves, around a plant floor, their flexibility and versatility greatly increase.

Flexibility has always been one of the biggest advantages of robotic palletizers; they can be programmed to assemble new pallet configurations much more easily than dedicated machines. ONExia takes that to a new level with the PalletizUR, a cobot from Universal Robots mounted on a skid that fits a forklift or pallet jack. As a cobot that does not require guarding, it takes up relatively little space, and being skid-mounted makes it easy to shift among packaging lines.

A step beyond portable robots like the PalletizUR are autonomous mobile robots (AMRs). These usually consist of a robot arm mounted on a platform big enough to hold a load of cases or other large packages.

AMRs have actually existed for more than a decade in a crude form, with the platform confined to a path delineated by a wire or other guide laid on or in the floor. But the new generation of AMRs use the same kind of technology used for driverless cars; in effect, they’re driverless forklifts.

Olympus Controls has done numerous projects that involve combining an AMR from MiR with a robot arm from Universal Robots, says Kevin Collins, Olympus Controls’ head of robotics business development. Although none of these has so far involved packaging lines, “I think it could be very useful on a packaging line," he says. End users could "combine the collaborative aspect with the picking and placing ability along with the material transport ability, so it can be an all-in-one solution.”

Robots have a lot of untapped potential for packaging lines. The key, Henry says, will be for line designers and integrators to recast their thinking to start with robots, rather than thinking of them as accessories or components of a packaging machine.

“I think that, for speeds to 200 parts per minute or so, robots could replace many packaging machines,” he says. “Someone will come along in the next two to three years and disrupt the industry.”