Press Release
Sequel's technology woven into intuitive design
Global design trends influenced the Sequel's designUnfamiliar technology can be daunting, but carefully executed design elements in the Sequel combine a number of advanced technologies in a comfortable and inviting package.
"The Sequel's design is forward looking, but doesn't allow the underlying technology to overpower the driving experience," said Ed Welburn, GM vice president of design. "From the sleek, clean exterior to the intuitive interior, Sequel reinforces the viability of the technology and connects the user to the technologies in a very comfortable and familiar way."
The Sequel is comparable in size to the Cadillac SRX crossover vehicle, measuring 1,696 millimeters in length, 1,696 millimeters in height and riding on a 3,040-millimeters wheelbase. Those dimensions lend a recognizable, yet forward-looking shape to Sequel, while enabling the functionality of the vehicle's fuel-cell power system.
"The layout of the chassis and fuel cell system required a vehicle with a SUV-like stance," Welburn said. "Contemporary crossover-type vehicles also appeal to drivers because of their combination of car and SUV attributes - attributes definitely woven into the Sequel, such as a flat floor for easier cargo loading."
And while hinting of the future, Sequel's seductive design is rooted in conventional driving requirements. That's because the Sequel will undergo a series of real-world driving evaluations in traffic and at highway speeds, meaning designers and engineers had to incorporate production-vehicle criteria into the vehicle's design.
The design team made sure the Sequel looked at home on the road.
"We designed a realistic vehicle," said Robert Boniface, GM director of advanced design. "The importance of the Sequel is that it's a realistic, driveable and credible vehicle, so its design had to reflect that. It doesn't look like an outlandish, unreal dream machine."
A multitude of details tie elements of the exterior and interior together, as if they were parts of a precise, mechanical puzzle. Almost no corners or parting lines meet squarely; rather, they appear to "lock" together.
"All the intersecting elements may not be visible or readily apparent, but they work together to tighten the overall look of the vehicle," Boniface said. "As a result, the Sequel looks and feels extremely solid."
Global design trends also influenced the Sequel's design, both inside and out. Designers anticipated near-future trends in shapes, colors, lighting and materials by studying everything from Scandinavian furniture to the latest Asian-designed cell phones and sports shoes.
Distinct identity
The Sequel's bold look incorporates several attributes to satisfy its unique cooling needs.Up front, the three large grille openings - a large, prominent grille in the center and two flanking inlets beneath the headlamps - feed air to a trio of large-capacity radiators. Besides providing cooling to the fuel cell stack, the radiators also cool the power electronics and front electric motor. On the hood is another air intake for cooling the HVAC (heating, ventilation and air conditioning) system.
More air inlets are surprisingly found at the rear of the vehicle, which feed outside air to cool the Sequel's rear wheel motors and battery pack. Typically, vents are placed on the side of the vehicle where the rear seat windows meet the back windows. The design team suggested developing rear cooling vents to enhance the exterior's styling.
"We asked the engineers if the vents could be moved," Boniface said, "and, after some careful studies of airflow, we learned the Sequel's thermodynamics actually improved with the vents under the taillights. So that's where we placed them."
The front-end styling also has unique headlamps and turn signals. The headlamps are made up of LEDs that magnify light through glass blades. This provides both superior light and a high-tech appearance. Also, the LED lights require less energy and create less heat than conventional headlamps. Their compactness and brightness allowed designers to develop lighting modules that are small enough to accommodate the radiator grilles beneath them. LED lighting carries over to the rear of the vehicle, too, making up the elements of the taillamps.
Sequel also has a full-length sunroof comprising separate sections that slide rearward. The windows and sunroof glass are tinted blue, which complements the light metallic green exterior color.
Interior integration
Sequel's interlocking design theme carries over to the interior. Elements are visibly integrated, from the floor panels to the seats. The vehicle's HVAC system is located under the hood instead of inside the instrument panel. Designers were able to rethink the role and placement of traditional controls. Instead of a center-dash control panel for the climate and audio system controls, individual controls for the driver and front passenger are located on the door armrests.Even the air vents are unconventional. Air wafts out from behind the "floating" instrument panel via a high-volume/low-pressure HVAC system, similar to that of a cabin-pressurized airliner.
Other instrument panel features include:
- Transmission selector stalk featuring two positions: Drive and Reverse
"The center console can be configured to meet many lifestyle needs," said Anne Asensio, GM executive director, advanced design. "It can deliver driver-oriented information, or it can become the hub of a shared conversation space that connects passengers."
The five-seat concept vehicle features a front passenger seat that can rotate 180 degrees when the vehicle is parked, so that the front passenger can interact more easily with the rear-seat passengers.
Rear-seat flexibility allows multiple configurations including: forward/rearward adjustment, seat back reclining and a seat bottom that folds vertically to allow a flat load floor between the rear doors.
Contemporary colors including plum, rice and wasabi, as well as metal and wood accents, complement Sequel's airy cabin.
Designers also incorporated a new gel material for the armrests and load-floor strips. The silicone-rubber material is translucent, permitting backlighting through the material to give the interior a comforting, ambient glow. The lighting theme is continued in LED-lit trenches in the instrument panel.
Sequel is an easy-to-operate, intuitive vehicle. It has a traditional steering wheel, accelerator and brake pedal even though it uses by-wire technology. Controls and instruments also are recognizable and logically placed.
"Our aim is to deliver technologies that make sense and bring real benefits to our customers," said Welburn. "The Sequel concept delivers high value in an exciting design statement, with surprising functionality, and it is very good for the environment."
Next Generation Fuel Cell System propels GM's Sequel
Improved 480-km range is made possible by advances in high-pressure storage.With a 25-percent more powerful fuel cell stack, GM's next-generation fuel cell power system helps Sequel achieve a 480-kilometer range and 0-100 kph acceleration in less than 10 seconds, while emitting only water vapor.
"Sequel is the first fuel cell vehicle in the industry that delivers the range and performance people expect from their current vehicles, bringing us that much closer to commercialization," said Byron McCormick, executive director of GM's Fuel Cell Activities.
Sequel's fuel cell stack and power module were designed and developed by GM engineers in Honeoye Falls, N.Y. The fuel cell power module is significantly simpler and more efficient than the module GM used to set a new world distance record for fuel cell technology in 2004 with a run of 9,640 kilometers through 14 European countries.
The fuel cell power module consists of the actual fuel cell stack, the hydrogen and air processing subsystems, the cooling system and the high-voltage distribution system. This power module delivers 73 kW of high-voltage power for the electric traction motors, as well as auxiliaries like HVAC (heating, ventilation and air conditioning), by-wire electronics and the battery.
"The system design has evolved and the components are becoming simpler, which is helping drive down the cost of technology and bringing us one step closer to reality," said Daniel O'Connell, head of GM Fuel Cell Product Engineering in Honeoye Falls.
Hydrogen introduced into the fuel cell is now directly converted to electric power to drive unprecedented torque control of all wheels. The two rear wheel hub motors including two inverters, as well as the power inverter module for the front electric motor, are developed by GM's Advanced Technology Center in Torrance, Calif. A high-voltage, lithium ion battery system provides extra power to the three electric motors during acceleration. It also stores power regenerated during braking to help extend the vehicle's overall mileage range.
Engineers at a GM fuel cell facility in Mainz-Kastel, Germany, integrated the fuel cell propulsion system into the vehicle package. The engineers linked the drive motor development with the rest of the system for a complete, vehicle-level, system solution. This led to an increase in the overall efficiency. It makes more power with less hydrogen, improving the performance and day-to-day operation.
GM's next-generation fuel cell also uses a new air intake system that is more efficient, quieter and lighter than its predecessor. The fuel cell stack, along with the cylindrical hydrogen storage tanks, is housed in a unique "skateboard" floor. Additional radiators are located under the Sequel's hood, directly behind the headlights, and in the rear of the vehicle, behind the taillights. These necessary design features help pull heat away from the fuel cell system, allowing Sequel to operate in hotter ambient temperatures.
"A fuel cell system is more efficient than an internal combustion engine, but its energy conversion is totally different and requires much more heat to be removed via the coolant," said Lothar Matejcek, project manager, GM Fuel Cell Activities, Mainz-Kastel. "With its three openings in the front, the extra opening for the HVAC and the two additional openings in the rear, you can easily recognize that Sequel was designed for heat rejection. We expect excellent performance at high ambient temperatures, typical of what you would experience in the desert."
