Top technologies of the year
"Onion-skin" SL hardtop from Car Top Systems
Traditional softtop convertibles have some practical shortcomings to go along with their obvious attractions. A potential solution is a folding hardtop convertible roof mechanism, but for many years the tradeoffs of such designs were greater than the potential benefits.
But recently the state-of-the-art has advanced significantly—via great effort from companies such as Merecedes-Benz and Car Top Systems—with fewer parts, greater reliability, and reduced intrusion into the trunk when folded. Building upon their experience in designing the Mercedes-Benz SLK "clam-shell" folding hardtop, the two companies have developed an improved "onion-skin" design for the SL that addresses the limitation of trunk space that was criticized on the SLK, according to Hans Knape, head of program management at Car Top Systems.
"Compared to the SLK, we spent twice the budget, we almost doubled the number of parts (from 300 to 577), we increased the weight from 46 to 65 kg—despite use of lightweight material—and increased the number of actuation cylinders from 7 to 13," said Knape. "But we reduced the consumed trunk space of the roof from 193 to 82 L and added an easy-pack function that allows drivers to load even suitcases in the top-down position."
The key was to flip the rear window so its shape nests inside the roof when the two are folded together, rather than folding them in opposition to create a space-wasting clamshell. The "easy pack" function means the stowed roof rests on a hinge, so that drivers can tip the stowed roof upwards 20° when they open the trunk lid for better access to the space available below the folded roof. Once the luggage is stowed, the roof pivots back down so the trunk can close.
For more information from CTS, circle 60
Q45 gets latest Visteon Voice Technology
Second-generation voice technology from Visteon Corp. made its first appearance on the 2002 Infiniti Q45 sedan, enabling voice-command control of the navigation, audio system, climate functions, and cellular phone. Visteon Voice Technology is "speaker independent, so it's not trained to one voice," said Bill Klingler, Voice Products Supervisor for Visteon. He added that slow, deliberate voice commands are counterproductive since the system "was actually designed for normal speech patterns."
Compared to the first-generation Visteon technology that debuted on the Jaguar S-Type, the second-generation product offering improves the human/machine interface (HMI). Consider the setup for personalizing/storing a radio station nametag; in the next-generation version, a voice command is given once instead of repeating the nametag storage command three times during HMI dialogue.
To issue a command, the user must press a button "so you always have control as a user as to when you want to issue that command," said Klingler. In the first-generation version, pressing a steering-wheel-located button activated the voice command system. Engineers added more in-vehicle speakers during the second generation's product development phase. The additional speakers, used to monitor in-vehicle noise occurring from idle to about 113 km/h (70 mph), resulted in improved voice models. An omni-directional microphone in the headliner and a push-to-talk button on the Q45 steering wheel are the system's main hardware components. The command process starts at the microphone and ends with the SAE J1850 vehicle bus relay to control audio, climate, and navigation. The technology on the Q45 provides speech-adaptation capability and can be particularly useful for people who speak English as a second language.
For more information from, circle 61
Six-speed ZF auto debuts in 7 Series
After appearing as a concept at the SAE 2000 World Congress, the ZF Group began producing in July 2001 the world's first production six-speed automatic transmission for passenger cars. The 6HP26 went from development to production in less than four years, and appeared first on the new 2002 BMW 7 Series. The new transmission has a maximum input torque of 600 N•m (440 lb•ft) at 4200 rpm. An overall gear-ratio range of 6.04 was selected to achieve comparatively low engine speeds at high speeds.
In addition to very compact design, simulations have shown that the new transmission offers a 13% reduction in mass, 5% better acceleration, and a 5-7% fuel-consumption savings while offering "fundamentally better performance" than the 5HP24 five-speed automatic transmission it replaces. Better fuel consumption was achieved not only through the addition of the sixth gear, but via a new low-viscosity oil developed by ZF as well as Stand-by-Control (SBC) electronic control. The latter system controls the transmission's input clutch so that the engine is disconnected from the driveline when the vehicle is stationary, even when in gear.
ZF engineers employed a Lepelletier-geartrain concept so the 6HP26 could use significantly fewer components. Compared to current five-speed automatic transmissions, which require three geartrains and six clutch elements, the new transmission requires only one simple and one Ravigneaux geartrain in combination with five clutch elements. The result is a transmission with a mass of only 89 kg (196 lb) with oil. It is also 50 mm (2 in) shorter.
The transmission's EM19 electronic control module was developed and is produced by Bosch and includes connections for the electrohydraulic actuators (pressure control valves, shift valve) and sensors. Gear selection is via shift-by-wire technology.
For more information from ZF, circle 62; from Bosch, circle 63
