The electrical-power-management and control strategies of Chevrolet's Volt extended-range electric vehicle and the brand's Equinox fuel-cell vehicle underscore the relevance of technology transfer among fairly distinct platforms and technologies.
"A fuel cell is an electrically driven vehicle," said Tony Posawatz, Vehicle Line Director for the Chevrolet Volt, General Motors' in-development extended-range electric vehicle. "It has a battery in it. It has an electric motor, and it has power electronics. It just happens to get some of its electricity from an electrochemical process that transitions hydrogen into electricity. So from a high-level perspective and looking at how expensive some of the technologies are, the more you can leverage the better."
Many of the technical specialists who worked on the Equinox hydrogen fuel-cell vehicle are now involved with the Volt. "There are a significant number of engineers and program support people that have transitioned to the Volt team," noted Mark Vann, Program Development Manager for the Chevrolet Equinox Fuel Cell Program. For proprietary reasons, Vann declined to reveal how many engineers made the switch, but he termed it a "meaningful number."
Since the Volt and Equinox are both purely electrically driven vehicles, their electrical-power-management and control strategies are very similar. "We have received a lot of feedback from Project Driveway participants on the feel of the brakes and have made several modifications to the Equinox fuel-cell vehicle," Vann noted. "And we have shared the real-world driver feedback and learning with the Volt team."
Consumers in New York, California, and Washington, D.C., have been driving Equinox fuel-cell vehicles for three-month periods, reporting their experiences to Chevrolet. "The (Project Driveway) program runs through the fourth quarter of 2010," noted Vann. Project Driveway is likely to get a second life. "We probably will do something like that in the middle of 2010 with the Volt," said Posawatz.
Technology exchanges are not limited to electrical-power-management and control strategies. The Volt and other vehicles employing "sophisticated technologies for fuel efficiency make use of regenerative braking, rolling resistance tires, and lightweight materials," noted Vann. According to Posawatz, the Volt's regenerative braking was a technology transfer from GM's two-mode hybrid vehicle programs.
The Volt is now in its development-mule phase. "We're building them as we speak," said Posawatz. About 24 mule development vehicles are likely to be built. GM is in the process of signing contracts with suppliers for the Volt. Toward the end of 2009, the program is expected to enter its integration phase. Volt's Assistant Chief Engineer Alex Cattelan said November 2010 is the Volt's production target date. "It's not a niche product. We expect it to be a volume product," Cattelan said.
Each of the 100 Equinox fuel-cell vehicles in the Project Driveway program uses a nickel/metal-hydride battery pack and three carbon-fiber fuel tanks to store onboard hydrogen. "I think the engineering is done on the Equinox and there are no additional changes to the current generation. However, when the next generation of GM fuel-cell technology hits the road, it will incorporate some of the advances made on the Volt," Vann noted.