Assembly in Action: Robots Solve Puzzle Problem
September 21, 2007
Recently, Ravensburger implemented a fully automatic robotic system, which directly links the company’s production facility to a high-bay warehouse-part of a longstanding commitment to automation.
Ravensburger Spieleverlag GmbH (Ravensburger, German) manufactures hundreds of different puzzles and games for the Western European market. In all, the company has created some 1,000 unique puzzles in a range of sizes to ensure its customers a constant array of new challenges. For the ultimate challenge, there are four 18,000-piece historical maps of the world that have even earned a place in the Guinness book of world records.
Recently, Ravensburger implemented a fully automatic robotic system, which directly links the company’s production facility to a high-bay warehouse-part of a longstanding commitment to automation. Originally, the company set out to simply upgrade an existing layering palletizer. But, the solution proved to be too expensive, so engineers decided to create a new system from scratch.
“Because our game packaging is very sensitive, we were looking for a solution that could palletize the boxes without damaging them,” says Michael Bahlinger, head of engineering at Ravensburger. “With the conventional layering palletizer, the puzzle and game boxes were not transferred to the pallet with perfect alignment, resulting in occasional package damage.” According to Bahlinger, the company also wanted a system that required less space and was easy to operate.
To design and manufacture the new system, Ravensburger brought in systems builder FPT Robotik GmbH (Amtzell, Germany), which designed and installed a forklift-free material-handling line employing a battery of six-axis robots from Kuka Robotics Corp. (Clinton Township, MI).
At the beginning of the line, a belt conveyor carries the completed puzzles to a series of four stacking stations. As it does so, the puzzles pass through a light grid, which measures their height and width. One of four KUKA KR 180 PA robots then picks up the boxes with a suction gripper-usually four or five boxes at a time-and stacks them to the correct height on a pallet waiting in the stacking position. As the robot does so, it leaves a gap between the individual stacks so they can be handled more easily later on.
“The gripper is unquestionably a major highlight of the system,” says FPT project manager, Harald Gläss. “The huge variety of different products means that it has to be highly flexible.”
To minimize downtime, each robot has two stacking positions. That way, if a conveyor goes down, the robot can switch to a backup position and production can continue unabated. The four robots are positioned so that if one of them fails its neighbor can take its place, again avoiding downtime.
Once loaded by the robot, a transverse shuttle carries the pallets to a series of wrapping and strapping machines. From there, a conveyor transfers them to a labeling machine, after which they are carried in a lift to the high-bay warehouse.
As the pallets are emptied, a fifth, KR 100 PA robot, picks them up, measures them with a laser-equipped gripper and then passes them through a cleaning station where they are vacuumed and brushed.
“This is important, as the pallets often get dirty on the way to the robot,” says FPT Managing Director, Hermann Müller. “If they are then stacked up again, the dirt is transferred to the upper surface of the pallets. This means that the products are stacked on a dirty surface.”
To coordinate the robots, FPT installed a KUKA controller along with KUKA.Sim Pro software and FlexOP user interface software from FPT. The KUKA software, in particular, proved invaluable during implementation, because it allowed Ravensburger to keep its employees involved during the ramp-up process.
“We held an information event in our production department in order to explain to the workforce exactly what changes would take place,” Bahlinger says. “Using KUKA.Sim Pro, we were able to present the project to our colleagues on a large screen, just like in a theater, thereby achieving understanding and arousing interest.”
For more on material handling robots, call 866-873-5852 or visit www.kukarobotics.com.
For more on automation, visit www.fpt.de/en.