Powertrain Control Research Lab celebrates 20-plus years of vehicle research
In 2010, the University of Wisconsin-Madison Powertrain Control Research Laboratory, or PCRL, celebrates 21 years of innovative powertrain systems research. In those years, researchers have designed and built a variety of cutting-edge transient testing systems, as well as unique new facilities.
Amid its technological advancements, PCRL has remained a lab dedicated to cultivating high-caliber students. Founder and director John Moskwa, a mechanical engineering professor, has spread interest in vehicle technology research to many engineering students via opportunities in and beyond PCRL.
20 years of powertrains
Hybrid vehicles may be prevalent on the roads today, but 20 years ago there were no commercially sold hybrid electric vehicles—rather, hybrid vehicles existed primarily in labs or experimental garages. Various hybrid designs have been explored and built in UW-Madison mechanical engineering labs since the 1970s, but the founding of PCRL in 1989 signaled a major new interdisciplinary approach to hybrid vehicle design and testing.
"Powertrain" refers to a vehicle's engine, transmission or gearbox, driveline, differential, axles and all support hardware and software systems. PCRL researchers study powertrain systems, which include detailed dynamic interactions of these various components.
In 2009, Moskwa and his students patented a new engine heat transfer simulator. In the past, engine and powertrain tests on single-cylinder engines ran at a constant (steady state) speed and temperature; however, cars on the street don't operate this way. The new system builds upon two previous inventions in PCRL and the lab's ongoing work with transient single-cylinder engine test systems, which include several patents for a test system that uses Hardware-in-the-Loop (HIL).
HIL is a synthesis of hardware, real time dynamic computer models and control software that replicates an entire vehicle. "We brought this new technology to the college in vehicle systems," Moskwa says. "It's one of the things that we're known for." Japan-based Horiba currently is working with the PCRL team to commercialize the technology.
To demonstrate how fast the system operates, Moskwa can set varying engine speeds to musical notes, allowing the transient test system to "play" pieces such as "On Wisconsin" and one of Bach's violin partitas on the lab's dynamometer. (see video)
"I can tell people that our slew rates are in excess of 10,000 RPMs per second, but when they hear the system they really understand how unique this is in terms of its capabilities," he says.
Hands-on experience for students
As a student, John Lahti (PhDME '04) helped design and build the lab's first single-cylinder engine transient dynamometer, a device that provides to or absorbs power from a research engine. He also developed a new engine control strategy for future powertrains, including homogeneous charge compression ignition engines. The third transient test system designed and built in PCRL, Lahti's system had transient capabilities unequaled in the world.
Now a senior project engineer at General Motors Powertrain in Milford, Michigan, Lahti works with hybrid control software and says PCRL gave him invaluable experience. "The greatest thing about working in the lab was my engine could stay on the dynamometer as long as I needed to do my testing," he says. "In industry, you might get one or two days."
Like Lahti, many of Moskwa's students go on to work in the automotive industry at companies that include Bosch, Caterpillar, Cummins, Ferrari, General Motors, Mercedes and Volvo, among others. Yet before they join industry, Moskwa's students have plenty of hands-on opportunities in PCRL, and some of them even had the chance to remake the lab itself.
During Lahti's era, researchers tested three different engines in one room, and the students shared instrumentation and wires among all three. When the Mechanical Engineering Building was remodeled in the mid-2000s, PCRL had its own opportunity for a make-over. Mechanical engineering PhD student Derek Mangun says so much planning went into the design of the new lab—from floor plans to hydraulics—that the team wrote a paper on the set-up alone. "It was an experience I'll value because people don't realize how many projects involve set-up," he says.
Mangun considers the lab's layout as its most attractive feature. Known as the DynoLab, the layout is separated into three individual test "cells," or rooms, plus an electronics build-room and a power-supply room to make testing safer. A separate laboratory houses computer stations for simulation work. "It is really approachable in a very organized fashion," Mangun says. "You can hear what's going on, and you can watch tests from the window or up-close for tuning." The new lab officially opened in 2006.
Moskwa readily credits the work done by past and current students in PCRL. "Everything you see in the new lab involves student-designed and student-built projects," he says. "I lead the big picture and help students along the way in terms of ideas, direction and technology, but the nitty-gritty work and research are done by students."
Moskwa provides opportunities for students interested in vehicle research beyond the PCRL lab. In 1991, Moskwa founded the UW-Madison hybrid electric vehicle (HEV) program and formed Team Paradigm. "In my lab we built a dynamometer system specifically for testing the first HEV powertrain for this competition hybrid vehicle and measuring its emissions," says Moskwa, who served as the faculty advisor to the HEV team in its early years. "That first team did an amazing job under difficult conditions, and members continued to either lead or advise the program for more than a decade afterward," he says.
Moskwa also teaches courses in vehicle design and dynamics, as well as powertrain systems.
The future of PCRL
As he walks past the lab's original controller box displayed in a glass case, Moskwa reflects on how far technology has come. "It's humbling to look back at our original dynamometer controller built in the lab because it's so archaic compared to our current system," he says. "Today we've tried to build on our technology, and now we have sophisticated technology that we've been able to bring to bear in the lab."
Moskwa would like to see his team use its expertise on other projects, such as advanced powertrain test facilities for companies with challenging development or testing issues. He also envisions PCRL facilities could be used for developing large wind turbine test facilities or power strategies.
No matter the lab's future directions, Moskwa says he can't help but feel a strong connection to the lab. "I sort of feel like it's my baby in some sense," he says.
"We've had some good successes over these years, I am very proud that the lab has an international reputation of excellence in powertrain systems and transient testing, and it has been a real joy to work with the students."