When it enters production this spring, Cadillac’s 2013 XTS will be the industry’s first vehicle to use directional tactile sensation—vibrations of the driver’s seat lower bolster—to alert its occupant of potential crash threats while on the road and in parking situations.
Using two small electric motors inside the cushion, the Safety Alert Seat generates pulses on the left or right side of the lower bolster to warn the driver of potential dangers, such as drifting out of a traffic lane or toward nearby objects while parking. Crash threats sensed from the front and rear trigger pulses on both sides of the seat.
The seat is part of two new integrated safety packages, dubbed Cadillac Driver Awareness and Driver Assist, and the brand will roll out on XTS, ATS, and SRX in MY2013. Both packages use multiple sensor inputs from onboard cameras, radar, lidar, and GPS to help drivers avoid crashes. The Driver Awareness Package includes forward collision alert, lane-departure warning, side blind-zone alert, and rear cross-traffic alert. The latter is designed to be most useful in parking lots and close quarters.
An exterior camera array provides drivers with a view of the outside of the car, along with dynamic parking guides, on an 8-in LCD screen located in the center stack. As an object is detected directly behind the vehicle as it backs up, the system sends a short burst of pulses to both seat bolsters. As the object gets closer, more pulses are sent. At the same time, the rear cross-traffic alert system looks for approaching cross traffic behind the vehicle and signals the driver with either left- or right-side pulses.
The Driver Assist Package, which debuts this fall, also uses the Safety Alert Seat. It features adaptive cruise control, automatic collision preparation, and front and rear automatic braking systems.
Seat vibrations can be driver-selected using an in-vehicle menu. System control algorithms “intelligently decide” when to activate warnings. If a turn signal is on, for example, lane departure warnings are not presented. At a recent media event at General Motors’ Milford Proving Ground where new safety technologies were discussed, GM engineers said the haptic alerts are an alternative to audible beeping alerts used by other OEMs.
GM researchers have been working on haptic-feedback technologies for many years, said Dr. Alan Taub, who just recently retired from GM as Vice President of R&D. The 2013 Cadillac seat is backed by at least two patents. One of them, number 7245231, is for a “collision awareness system that utilizes haptic alerts.” GM Active Safety Technical Fellow Raymond Kiefer, along with colleagues Donald Grimm, Bakhtiar Litkouhi, and Varsha Sadekar, are named in the patent which covers 2007-2025.
The second patent, number 7714701, is for an “active material-based haptic alert system.” It names as patent holders GM Global Technical Operations engineers and researchers Osman Altarn, Alan Browne, Nancy Johnson, and Brian Roper.
A patent search by AEI revealed that many other OEMs and suppliers hold or have applied for patents in the haptic-vibratory seat space, including Aisin Seiki, Faurecia, Ford, Lear, Matsushita Electric, and PSA.