Inside Iowa State: Iowa State University

July 03, 2003

When push comes to shove

by Linda Charles
It's easy to push a wheelbarrow designed to carry one bush, but one made to carry 100 bushes would take too much strength and be too unwieldy to use.

That's the sort of problem Iowa manufacturer Positech came up against in the late 1990s. The Laurens company, a division of Columbus McKinnon Corp., custom designs "material handling manipulators" -- machines and robotics that reduce the amount of human effort it takes to move things around.

"We're problem-solvers," said company president Peter Hong. The problem facing Positech was the need to move massive items, whether on the loading dock or the production line. But the manipulators were becoming too big and taking too much strength to be practical.

"We could build it," Hong said, "but you wouldn't want to use it."

That's when Hong contacted Iowa State's Greg Luecke, associate professor of mechanical engineering and a member of the Virtual Reality Applications Center (part of the Institute for Physical Research and Technology).

Luecke and his team of graduate and undergraduate students created a virtual reality model of a robotic arm to determine the ratio between human effort and machine force, then designed joints and a control system. The result of the three-year project is a computer-controlled manipulator that uses amplifiers, motors and a processor to let the operator smoothly rotate and move super heavy loads.

"It's not really a robot and it's not really a manual piece of equipment," Hong said.

The new manipulator literally turns pounds into ounces, Hong said. Positech began selling it in 2000 and now "slices and dices" the technology designed by Luecke to customize manipulators for other companies. For example, one of Positech's manipulators is used to move 1,500-pound agricultural tires.

The new technology "spawned a whole new industry," Hong said.