By Bill Moore
Chris Borroni-Bird is a quiet-spoken Englishman with a Liverpool accent that reminds you of the Beatles. He is the program manager for the innovative - - maybe even radical - - AUTOnomy concept vehicle.
One week after GM unveiled this extraordinary concept vehicle at the 2002 North American International Auto Show, Chris spoke to EV World about the program, revealing that his team hopes to have a working first generation version of the vehicle running by the end of this year. And while the mockups shown at the Cobo Convention Center, where just that, mockups, serious efforts are underway to turn plastic and steel dreams into a real working prototype.
Borroni-Bird began our interview with an explanation of how the concept all came about. He began by saying, "We were given the challenge of designing what a vehicle designed around a fuel cell might look like. Up to now every vehicle that has been demonstrated by GM and our competitors have basically taken an internal combustion engine [vehicle] and taken the engine and transmission out and replaced it with a fuel cell and an electric motor and controller. These are very conventional looking vehicles, of course, with graphics on the side saying they are fuel cell-powered."
Instead, the GM team realized early on that fuel cell technology was improving "by leaps and bounds." Because power density was improving, the size of the stack was also shrinking, requiring less and less space inside the vehicle.
"It became possible for us to imagine not only putting the fuel cell stack under the floor, which is what many of our competitors have been doing, putting the whole fuel cell propulsion system under the floor, including the electric motor and controller, so that you get rid of this engine compartment hood that we have today," he stated.
But what really enabled the AUTOnomy concept to evolve was the development of X-wire drive-by-wire technology developed by a Swedish firm, Borroni-Bird explained. By eliminating the need for mechanical and hydraulic linkage between the passenger compartment and the vehicle drive train, it became possible to develop what GM engineers call the "Skateboard," an autonomous, self-contained drive train chassis. [See photo above. Click here for large diagram of Skateboard components].
Integrated into the Skateboard would be the fuel cell stack, power electronics, hydrogen storage tanks, collision absorption materials in the front and rear, along with cabin environmental systems and the X-wire docking system.
According to Borroni-Bird the marriage of fuel cells and x-wire makes a great deal of sense because the drive-by-wire system requires 42 volts to function, which the fuel cell can easily supply.
"Both will be available in the next five to ten year time frame, but we¹re not quite there yet," he added. "We believe that is the future for the propulsion system and chassis respectively."
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