If you've ever seen a car commercial set in a laboratory -- tires of a motionless vehicle spinning on rollers like a treadmill for sedans -- you've seen a dynamometer in action. Used for measuring force, torque and power, dynamometers can be as simple as a small spring.
On the other end of the spectrum is Iowa State's new $2.9 million dynamometer approved by the state Board of Regents in April. Among the world's many publicly available chassis dynamometers -- the kind with rollers, like on car commercials -- Iowa State's will be one of the few capable of testing large construction and farm machinery, including tractors, combines and wheel loaders.
A range of research
Having a controlled setting to evaluate the performance of off-highway vehicles will allow faculty to expand research in emerging areas, said Brian Steward, professor of agricultural and biosystems engineering. That could mean extending to off-road machinery some concepts already familiar in on-road passenger vehicles, he said. Think tractors with traction control and fuel efficiency ratings.
"You can set up your test conditions much more specific to what you'd want to understand than you could in a field test," Steward said. "It really complements what we can do in the field and what we can do with components."
Design is underway on the facility, which is expected to break ground this fall and be in operation by next summer in a 5,000-square-foot building at the Agricultural Engineering and Agronomy Farm, about 4 miles west of Ames on Highway 30.
Based on preliminary designs, the dynamometer would feature four sets of seven independently controlled rollers, each about 18 inches high and set inside trenches about 7 feet deep, Steward said. Motors connected to the rollers will help gather energy released by vehicles being tested, converting it to electricity that will be distributed back to the power grid.
The multiple rollers clustered in four corners provide more surface contact and allow tests of vehicles propelled by both wheels and tracks, he said. Though built with the capacity for massive heavy equipment, it also could handle vehicles as small as skid-steer loaders and passenger cars.
"Those are the things that make it unique," he said. "A lot of it is the range of powers."
Valued experience
Students will benefit from the dynamometer because they'll be working with the techniques and data used to assess sophisticated control and sensor systems increasingly common in vehicles of all types, Steward said. It would be valuable background for working on driverless cars, for instance.
"In order to develop those systems, you need to be able to test them. Students going into the industry need some perspective on what the testing looks like," Steward said.
The facility will be available to industry for a fee, which Steward expects will generate significant interest. One company certain to use it is Danfoss Power Solutions, which contributed $1.8 million to the dynamometer project -- nearly two-thirds of its cost.
A private partner
The largest non-governmental employer in Ames, with 1,100 workers, Danfoss makes hydraulics and electronics for heavy equipment manufacturers like John Deere and Caterpillar. It also develops and improves systems for off-highway vehicles, looking for ways to improve performance and efficiency, said Dave Wohlsdorf, senior director for strategic innovation platforms and processes.
Danfoss tests those systems in computer simulations and real-life operations at its Application Development Center in Ames -- "a playground for engineers," as Wohlsdorf called it.
"But the one thing we don't have is a laboratory to test complete machines," he said. The dynamometer will provide a setting to collect accurate, precise, repeatable data that's difficult to obtain in outdoor environments, he said.
There are other upsides. Assisting Iowa State with the facility's funding will better prepare students Danfoss wants to hire. Its workforce is about half Iowa State graduates, and nearly all of the dozens of interns it hires each summer are Iowa State students. Engineering students working on research projects at the dynamometer will be ready to jump right in at Danfoss, Wohlsdorf said.
"We saw this as a great opportunity," he said. "We could have built this laboratory all by ourselves. But it makes more sense to do it with a partner using it for research."
