We here at DailyTech
have profiled fuel cell vehicle on numerous occasions. Companies like General
have showcased both concept and production hydrogen fuel cell vehicles over the
year and they have always generated much interest from our readers.
recently given a chance to take a fuel cell vehicle out onto the streets of Las
Vegas during the 2008 Consumer Electronics Show (CES).
The vehicle tested, the fuel cell version of the Chevy
Equinox, was modified to include an electric motor, fuel cells, hydrogen
storage, batteries, and more. The key component is GM's fourth generation
fuel cell stack which is about the size of an inline-6 engine turned
sideways. A single 97 HP, 236 lb-ft co-axial electric motor drives the
front wheels. The car has a pack of nickel-metal hydride batteries, which
provide 35 kWh of on demand power for peak loading during acceleration.
The car features three 10,000 psi storage tanks which can hold up to nine pounds
of hydrogen. Two tanks are found beneath the rear
seat, and one is mounted near the rear suspension. The car has enough
fuel for a 200 mile trip as verified during EPA testing.
The car looks similar to its non-fuel cell
brethren save for a new front grill, bumper, revised interior trim, four exhaust
outlets and a snazzy silver-green paint job. The car also is slightly
heavier, adding an additional 500 pounds to the standard curb weight of 3860
lbs. It does 0 to 60 mph in about 12 seconds – quite slow by modern
standards for a crossover.
It also includes protection against water vapor freezing in
the stack and can start up at sub-freezing temperatures -- a first for limited
production fuel cell vehicle. Life expectancy of the fuel cell stack is
still low at 50,000 miles, due to stack corrosion, but this is expected to be greatly
improved in the next revision. The car is extremely safe, both with
standard safety features, and passing crash testing with a running hydrogen
system. These tests were conducted under careful government supervision
and the Equinox Fuel Cell passed them with flying colors.
A limited fleet of 100 vehicles is being deployed to
California, New York, and Washington to select participants,
but until then only a select few lucky individuals, including DailyTech's Brandon Hill and Jason Mick
have been able to experience the Equinox.
begin our road test of the Equinox, Jason Mick and I had to show proof that we
had valid drivers licenses and sign two wavers: one for GM and one for CEA.
After taking a brief walk around the vehicle, I was given the keys to the
vehicle and asked to hop into the driver seat.
was given an overview of the gauges which are slightly different from a normal
internal combustion engine (ICE) Equinox. In place of the tachometer was a
gauge to give the status of the fuel cell stack. Otherwise, things looked quite
normal to me. I buckled up, turned the key to start the vehicle and there was
just silence -- no starter sounds, no engine running; just an eerie silence.
adjusted my mirrors, released the hand brake, put the vehicle in drive and took
off into absolutely crazy Las Vegas traffic. As I was driving, I could hear no
sound from the electric motors or fuel cell stack -- all I could hear was a
slight wind noise around the A-pillars and thumping from the suspension as the
wheels traveled over bumps/potholes in the road.
response was instantaneous as there is no transmission to speak of (the
electric motor is direct drive) and 236 lb-ft of torque available at any time.
It was truly no different than driving another vehicle and I felt right at
home. The only detraction from the driving experience was a somewhat spongy
brake feel. I was assured by the GM engineer that this was simply a programming
issue and this particular vehicle had not yet received the latest software
update which resolved the problem.
Brandon's drive I was eager to get behind the wheel of the Equinox
myself. The ignition is very different from starting gas engines.
Instead of a pushed turn, followed by a release as with most cars, you just
clicked and instantly the car was on, starting up. On my drive, our guide
pointed out that when the car started up a LCD panel on the center of the dashboard
console illuminated displaying an animation of how the engine was running, the
basic flow of water, H2 gas, air, and electricity through the system.
the car on the city streets, the biggest difference was the responsive
acceleration, which was very linear, as opposed to a gas engine vehicle.
The result was made starkly apparent when the light turned green I would whoosh
steaming past the lead-footed taxi drivers and sports car riders, who looked
utterly shocked that they just got passed by an SUV. I'm no race car
driver -- the acceleration, was simply that much better, making a car like this
great for the fast start, fast stop, nature of city driving.
On an empty stretch of street I did manage to take the car up to about 55 to 56
mph, where the acceleration harshly leveled off. The reported top speed
was 100 mph, but I believe GM speed limited the vehicles to 60 mph, to prevent
the riders from getting carried away. Thus, this is not necessarily
indicative of the vehicle's speed limitations, but I can happily report it was
quite responsive in reaching highway speeds.
An additional observation was that the steering seemed extremely smooth and
responsive. The vehicle turned very smoothly.
We both rode in the Chevrolet Tahoe DARPA Challenge
vehicle. The SUV was the victor in the DARPA
2007 Urban Challenge, which tasked the fully-autonomous vehicle with
navigating through city streets, obeying all traffic laws and interacting with
The vehicle was a modified Tahoe with a number of GPS,
video, laser, radar, and LIDAR sensors and inputs so that it can see the road
and know its location. The key among these sensors is the velodyne, which
contains 64 lasers in a wide array, spins at 10 Hz., and collects one million bits
of data per second -- this provides a 3D view of close terrain. While
other teams had velodynes the key to GM's victory, according to its engineers,
is how the collected data is processed. The processing and decision
making is accomplished by 10 Intel dual-core IBM blades running on a modified
version of Ubuntu Linux called the Tartan Racing Operating Command System
(TROCS). The vehicle's logic consists of over 350,000 lines of
code. The entire system was built in 14 months for the challenge, via a
collaboration of Carnegie Mellon, GM, Caterpillar, and Continental.
GM spoke about the vehicle during its keynote address at CES
2008, and stated that it sees it as the next step in the evolution of such
technologies as autonomous cruise control and blind spot management.
We got in the vehicle after an interesting presentation, and noticed that there
was plenty of room to sit comfortably -- the electronics did not encroach on
passenger space and were cleanly wired. The vehicle had a number of
appended mechanical devices that simulated the foot on the pedals, so that the
default pedal system could be used.
Taking off, the vehicle deftly accelerated and braked, steering through a complex
obstacle course that would give many human drivers problems. It obeyed
traffic laws, stopping at stop signs placed on intersection of the course and
properly yielding right of way. The ride was generally quite smooth,
though the braking was a bit jumpy at times. The engineers explained such
issues would be ironed out with time, and that given the very short 14 month
development period, incredible progress could be made in a relatively short
span to fine tune the vehicle.
The car's greatest moment of glory came when it approached a stop sign and saw
a human driver in a different vehicle coming up on the stop sign from the left.
As the human driver was fast approaching, the Tahoe accelerated from the stop
sign, and then rapidly braked, despite having right of way. The human
driver braked just in time to avoid running the stop sign, but it was very
reassuring to notice that the Tahoe "saw" him and would have avoided
the accident, had the human driver ran the sign. The engineers verified
this is normal behavior -- the vehicle can deal with erratic behavior such as
cars running stop signs, swerving into lanes, etc. caused by less logical human
The smooth ride, and the incident where the Tahoe almost
saved us from a crash, showed that in terms of ride quality and safety, the
system seemed at least as safe as a reasonably able human driver, if not
safer. Obviously tremendous work will have to be done to compact the
system, reassure the public, and make the system capable of handling every city
street in the country. Still, it is impressive just how far the
technology has come. A fully autonomous car is not that far in the
future, as our ride in the GM's DARPA winner showed us.
Both vehicles show the terrific things GM and the auto industry are
accomplishing as they work hard to make cars, safer, easier to use, cleaner,
and more efficient. DailyTech
thanks GM for this terrific opportunity to explore these innovations