Robotics Increase Performance, Reduce Labor

Oct. 1, 2002
Handling products from single or multiple lines, building single-product or multiple-product palletloads, loading trailers or lift trucks -- these machines can do it all.

Industrial robot sales, in general, are lagging previous years. There is, however, some encouraging information for the material handling sector, according to Donald A. Vincent, executive vice president, Robotics Industries Association (RIA).

“It’s clear that the robotics market continues to suffer from the weak U.S. economy,” says Vincent. “However, material handling robots are sold into a broad range of industries and represent the largest application area for the [robotics] industry.”

Vincent says new orders grew about 20 percent in the second quarter of this year, reversing several quarters of decline. Growth in material handling orders usually indicates that the robotics industry is making inroads in reaching customers in industries such as consumer goods, food and beverage, pharmaceuticals and other non-automotive markets — a key to long-term success.

RIA estimates that about 122,000 robots are now in use in U.S. factories, placing us second behind Japan in robot use. The association bases its reports on actual totals provided by its member companies, which RIA estimates represents more than 90 percent of the robotics market.

Robots serve transport packaging

Speed, accuracy and consistency are elements that can make or break productivity. While robotic palletizers are versatile and can handle bags, boxes or barrels, they are also islands of automation that must be properly integrated into the total supply chain.

Robotic machinery looks rugged; however, its tasks might include handling fragile cereals or expensive perfumes as easily as cases of motor oil or bags of cement.

An example of integrating a system to assure uninterrupted throughput, using robotic palletizing at the end, is the work done for Kraft by Siemens Dematic. Working in a 100-year-old building was only part of the challenge. Another part was the product — wheat-based fragile cereals.

After carton sealing and transport, an accumulation conveyor feeds cases to induction belt conveyors. During induction, carton labels are scanned and information directing the case to one of eight palletizers (from RMT Engineering) is collected.

Chain-driven transfers are used at sortation, using pusher bars to gently and squarely align cartons at the palletizer station in-feed line. The eight transfers are driven by AC servo motors that match palletizer speeds and damp the transfer motion for secure handling.

Palletizer clamping arms take rows of cartons and, on a belt conveyor, build load patterns based on the package size information derived from scanning the bar code label. When a load is complete, a transfer car comes to the station, receives the load and delivers it to a belt conveyor. The belt conveyor feeds the turntable of a wrapping machine. The wrapped load is transferred onto a heavy-duty accumulation conveyor and delivered to shipping.

Innovations in palletizing

Paul Probst, vice president and general manager, von Gal, a division of HK Systems, says major improvements in conventional palletizers include changes in servo-pneumatics and internal braking system pneumatics.

“What this means,” Probst explains, “is in slower speed or lightweight applications, there will be new, low-cost, pneumatic gantry-style machines on the market.”

Currently the majority of gantry-style palletizers are servo-electric.

Articulated arm robotic palletizers can’t match the speed of gantry-style. They are more successful in applications that require palletizing product from multiple lines. Most often these machines are used in slower production scenarios. If you opted to use a traditional palletizer for this type of application, you’d have to queue layers or lines of products, taking up more floor space and sacrificing flexibility.

“When you start handling 20 or more cases per minute,” says Probst, “the articulated arm robot has to pick up layers and is not as cost effective as the conventional palletizer.”

For low-speed, multiple-SKU applications, palletizing with an articulated arm machine is hard to beat.

A conventional palletizer, at high speeds, allows multiple movements to be made at the same time while an articulated arm palletizer, by nature of its design, can do only one thing at a time, albeit, gracefully and with great precision.

Probst says his company will be introducing a new form of controls that incorporates some of the gracefulness of articulated arm robots, in a conventional palletizer at Pack Expo International 2002.

“Every time you create a layer on a pallet,” he explains, “you’re jerking the load. So the more gently you can configure the load the less you disturb the pattern before you stretchwrap it.”

Directions in software

Palletizers can do just about anything. You just have to tell them what you need. And you have to tell them precisely. Fanuc Robotics has released Random Order PalletTool to automate mixed-load palletizing. When integrated with a Fanuc robot and system controller, this software tool creates an efficient method of setting up, controlling and monitoring mixed-pallet applications.

The applications best suited for this product are those typically found in distribution centers where products are individually selected and manually palletized.

Using the PalletTool, a robotic palletizing system can be set to monitor a random sequence of cases with random sizes to build an efficient pallet pattern with high density and stability. The system is designed to pick cases from an infeed buffering zone and place them onto a corresponding pallet. Prior to entering the infeed buffer area, the cases are passed through a peripheral identification device to obtain case characteristics.

Fanuc Robotics North America Inc.’s new M-420iA is a four-axis, modular, electric servo-driven robot with a 40-kg payload and a remote control unit. The machine is designed for a variety of high-speed manufacturing applications including packaging, palletizing, material handling, machine load/unload and parts transfer. At Pack Expo, the M-420iA robot will demonstrate high-speed packaging. Two robots will work together to pick and package cases at rates up to 50 cycles per minute. The M-420iA and M-421iA offer the fastest motion speeds in their class, which results in reduced cycle time and improved productivity.

“These robots can reach speeds significantly faster than previous-generation packaging robots,” says Matt Job, Fanuc Robotics’ product manager.

The M-420i robot, equipped with PalletTool off-line pallet creation software, will demonstrate high-speed palletizing by handling cases at rates up to 26 cycles per minute. “By reaching rates of up to 26 cycles/minute, infeed and tooling can be simplified,” says Job. “By simplifying tooling, we’ve eliminated the need for costly and complicated layer- or row-forming devices.”

PowerBot from ActivMedia Robotics is a robotic automatic guided vehicle (AGV) unique in its ability to navigate intelligently among moving obstacles. Most industrial vehicles are pre-programmed to repetitive motion. With PowerBot, goals can be scheduled, selected and changed on the fly. The database can plot paths around moving objects on the fly. All it needs is the goal, not the path, like most AGVs.

As for what it carries — that’s up to the user. ActivMedia can supply support for customization of the platform for particular applications.

Samsung’s PL2 is a 4-axis horizontal robotic palletizer. It can place up to 20 cases, bags, bundles, pails or trays per minute onto two different pallets. It can also pick up the pallet, thus eliminating expensive pallet magazines and pallet transfer magazines. Its unique finger pickup head enables picking unwrapped “display” cases or trays. Standard features include off-line programming, open architecture and a 3.5-inch floppy port.

The Viper robot line for material handling and processing applications from Ventax Robot Inc. takes advantage of the features offered by articulated and linear robots. It is designed specifically to combine user-friendly operation with flexibility, speed, accuracy and the most current technologies.

“The new Viper top-entry and side-entry product,” says Rick Delogu, Ventax CEO, “offers a unique arm design that combines ‘Y and Z’ function, eliminating one full axis.”

Ventax’s integrated servo controls feature a smart servo, relay isolated I/O, Panasonic drive technology and a fully teachable hand-held pendant capable of saving 16 online programs. Now, precision part removal and placement, along with minimal headroom and quick program changeovers, allow for reduced downtime and increased production efficiencies.

The MultiPick system from Swisslog is ideal for picking returnable plastic crates, totes and other containers. The system is designed for continuous picking of full-case quantities. The robot builds mixed-article stacks in exact order quantities and dropping sequences required for routing by the customer.

During the past two years, Alvey and Motoman have worked jointly to bring together the best of both palletizing worlds. FKI Logistex Alvey Systems’ 942 Series robotic arm is a key part of this palletizing cell, adding flexibility to the design and offering space savings due to its small footprint. MHM

Let Robots Do the Heavy Lifting

Developing and bringing on-line a massive production operation for Dodge Ram truck chassis frames, the Tower Automotive Plant in Milwaukee required the latest in manufacturing technology.

The project team focused its attention on the containers used to transport the box frames from the forming area to the weld area. Container manufacturer Topper Industrial worked with the development team at Tower to tackle this material handling project.

Once parts have completed their hydro form process, two material handling robots grip the frame and transfer it over to a crate. One robot handles right-side frames, the other stacks the left-side part. From there the parts are moved by lift truck to the start of the assembly process.

ABB, the maker of the robot, and Topper worked together to integrate robotic loading, unloading and material transport systems. While a robot is busy stacking frames, it also counts the parts it puts in the rack. To rehearse and fine-tune the operation, Topper and ABB ran prototype programs.