The 2013 Cadillac ATS luxury sport sedan offers visibility from the driver’s seat that inspires the same confidence as the North American Car of the Year’s acclaimed road-hugging performance.
Engineers worked to identify the vehicle attributes needed to maximize ATS’s driving character by making the most of sight lines. New visibility metrics developed from customer clinics in the United States and Germany consider exterior mirror and A-pillar area size, seat height, forward vision distance, side vision distance, and intrusive objects in windows such as rear headrests and the interior rearview mirror.
“Conducting clinics in Europe as well as the U.S. provided invaluable insight into the needs of drivers who use demanding roads like the Autobahn,” said Raj Mehta, General Motors vehicle architecture engineering group manager. “The findings led to new ways of measuring and evaluating visibility despite its highly subjective sensory nature.”
As with many cars today, ATS’s driver visibility is significantly influenced by design criteria, including aerodynamics, styling, structural stiffness, safety and vehicle packaging. The steeply raked windshields and A-pillars common today help make the most of aerodynamics for improved fuel economy, and higher hoods help provide pedestrian protection. Together, these measures can present visibility challenges.
Likewise, thicker roof pillars needed to accommodate air bags, lower roof heights required to decrease frontal area for improved aerodynamics, and higher decklids designed to accommodate customer cargo needs also pose visibility challenges.
A new visibility evaluation technique – known internally as “the Hedgehog” for its prickly appearance on computer screens – helps characterize the three-dimensional aspect of A-pillar sightlines. Designers can quickly study how changes in windshield angle or section size affect the driver’s ability to see targeted areas derived from careful evaluation of performance driving scenarios, such as the roads and tracks of the company’s Milford Proving Ground.
These findings were validated and used to create a Driver Visibility Calculator.
ATS achieved a “very good” internal score for forward visibility because the development team kept the hood low and the A-pillars slim through the use of high-strength steel. Designers positioned the A-pillars wide to allow a broad field of view and angled towards the driver to require minimal head movement to peer around. They also designed a narrow support structure for the exterior rearview mirrors, leading to a “very good” internal score on cornering visibility through turns.
The driver’s rear view is aided by the ATS’s available rear vision camera with dynamic guidelines. The camera provides a natural view of objects directly behind the ATS in the center stack display. Dynamic guidelines laid over the video image assist in parking maneuvers by showing the vehicle’s path and available space.
The rear vision camera is part of Cadillac’s “control and alert” strategy that employs advanced technologies such as radar, cameras and ultrasonic sensors to help prevent crashes. These technologies bolster driver vision and awareness of road hazards, and intervene to help the driver avert potential crashes.
“Smart design and the use of advanced materials like ultra-high strength steel help provide ATS drivers with a clear view of the road ahead and advanced technologies help extend their vision around the car,” said David Leone, executive chief engineer. “Our ability to execute good visibility based on robust scientific methods will be an important tool in the development of Cadillacs to come.”
Courtesy of GM News
