Used Cars and New Technology

That time when the United States Air Force Research Laboratory bought a Toyota Prius to try and understand its advanced power system.

Air Force Research Lab

As an engineering student at the University of Dayton, I spent my college summers working at Wright-Patterson Air Force Base (WPAFB) outside of Dayton, Ohio. I was a civilian contractor working in a power systems lab for the US Air Force Research Laboratory (AFRL) Propulsion Directorate, spending my days running computer simulations, setting up aircraft generators on drive-stands, and designing new experimental electrical test setups.

Department of Energy

One day, another researcher came by our lab with an interesting report from the Department of Energy (DOE) and wanted to ask us some technical questions about electrical generator design. The DOE report was a technical study of a 2004 Toyota Prius hybrid electric vehicle, published by the FreedomCAR and Vehicle Technologies Office which tested and evaluated new hybrid electrical vehicle designs. It’s a fascinating read with a lot of technical detail on electro-mechanical design of an electric vehicle, and I recommend giving it a read if you’re interested in that kind of thing!

A Prius Teardown

But as I skimmed through the report, I had a funny realization. Here was the US government’s Department of Energy, with all of its storied lineage of designing nuclear weapons and nuclear reactors, buying and reverse-engineering the electrical system of a foreign, commercial automotive vehicle just to figure out how it worked. Back then, the Prius had some innovative electro-mechanical design work in it, specifically related to its permanent-magnet generator (PMG) design. So the idea of the US government buying one just to tear it apart and study it to figure out how it worked was kind of funny to me!

And to top it off, the other researcher was looking at the report to assess permanent magnet (PM) technology for potential use in military aircraft. Historically, aircraft didn’t use PM generators, partly because of electrical excitation issues, but also because the military has always been concerned about becoming dependent on the supply of rare earth permanent magnets from China. But the DOE report on the Prius motor-generators showed such high power density performance for an electrical generator that the Air Force was interested in evaluating the technology for military aircraft.

No Seriously, How Does It Work?

And apparently, the DOE continued evaluating commercial hybrid electric vehicles, as noted in a follow-up 2010 evaluation of a newer version of the Toyota Prius.

“The PEEMRC performed subsystem benchmarking assessments of the 2004 Toyota Prius HEV in 2004–2005. This work has been fully reported in two reports [2,3]. Similar research and testing efforts were conducted with the hybrid subsystems of the 2005 Honda Accord [4], 2007 Toyota Camry [5], and 2008 Lexus LS600h [6] in 2006, 2007, and 2008, respectively.”

More Electric Aircraft

I’m not sure how or if AFRL has pushed PMG technology in new military aircraft design, but the overall idea of a More Electric Aircraft (MEA) is an ongoing area of research and design in the aerospace industry.

Just Buy Used

The moral of this story is that sometimes innovation crosses boundaries between industry and government, and sometimes the government just needs to buy a used car to figure out a new technology!