This fall, eight manufacturers made technology presentations to the Automobile Journalists of Canada (AJAC) journalist panel as part of the annual Car of the Year testing. They were vying for the title of “Best New Technology”.
Jaguar was one of the presenters and chose safety for their presentation. They showcased their new Adaptive Restraint Technology System found in all 2001 Jaguar XK series cars. Will they win the “Best New Technology Award” or will it one of the others described in this series of articles? Read on and you can be the judge.
Jaguar’s Adaptive Restraint Technology System (A.R.T.S.) is the next step forward in integrated vehicle safety. Seatbelts and airbags have been protecting vehicle occupants for many years, but the systems were designed for the “average” person. Many automobile occupants don’t fit the average, and their protection was not optimised. Jaguar is set to change that.
Dual stage air bags are used for both the driver’s side airbag in the steering wheel and the passenger airbag in the dash. The driver side airbag operation is optimised for different size drivers. An electronic sensor in the seat track measures the for-aft position of the driver’s seat. A seat belt buckle sensor tells the system whether the belt is being worn. Crash sensors at the front and sides of the car measure the severity of a crash. All this information is processed in the system’s central computer and a decision on how to operate the system is made in as little as 10 milliseconds (1/100 of a second).
In less severe accidents, the airbag is deployed using lower stage-one energy. In more severe accidents, the system deploys the airbag depending upon driver position. If the driver’s seat is too close to the steering wheel, again stage one is used. Driver’s sitting back from the steering wheel will have the more powerful stage-two airbag operation.
The seat belt buckle sensors are also used to determine which stage to use. If the belt is not on, then the system activates stage one operation to reduce the force on the driver as they are thrown forward.
Seat belt pretensioners are an integral part of the system. During a crash, the pretensioners pull the occupant back into the seat to secure them firmly. It also positions the occupant properly so both front and side airbags can provide the best protection. If the seat belt is not buckled, the pretensioners are not triggered. This reduces repair costs after an accident, because the pretensioners must be replaced after they are activated.
The passenger side airbag uses two special sensors. A silcon-filled bladder in the bottom seat cushion sends passenger weight information to the computer. The computer operates the airbag using one of three weight categories. If there is no passenger in the seat, the airbag is not deployed. If a small child is in the seat, the system is deactivated and a light illuminates on the dash to indicate the system is turned off. Larger children and adults allow full operation of the airbag in either of its two stages.
The second special sensor is mounted actually a group of four ultrasonic sensors mounted on the windshield post, the post behind the door, and two in the roof console. These sensors determine the position of the passenger. Airbag deployment is based on whether the passenger is “in position” or “out of position”.
In addition to the front airbags, seat-mounted side airbags provide protection for the head and rib cage in moderate to severe side impacts. There are two main advantages of the Jaguar A.R.T.S system. Passenger protection is tailored to the size and position of the occupant. The second advantage is reduced repair costs after and accident because the system is only activated if it will help protect the occupants.
Right now this technology in only available on Jaguar XK series cars. In the future, this technology can readily be adapted to other automobiles. Will it win AJAC’s “Best New Technology” award? Perhaps.