Autoliv Presents Solutions to Airbag Problems
10 September 1997
Autoliv Presents Solutions to Airbag ProblemsSTOCKHOLM, Sweden, Sept. 10 -- Autoliv Inc. , a worldwide leader in automotive safety, today presented its solutions for children and other occupants who risk getting injured by a deploying airbag. Autoliv made its presentation at a press conference at the International Auto Show in Frankfurt, Germany. Autoliv's solutions have already been tested in different car models -- both in the United States and Europe -- following initial, extensive laboratory testing. The solutions include an advanced, computerized sensoring system which has been "trained" to recognize and differentiate between 450,000 different positions of the front-seat occupant. The computer updates its pattern of the front seat every 50 milliseconds -- half the time of a blink of the eye. The system can thereby detect the slightest movement of the front- seat occupant and suppress the deployment of the airbag, should the occupant come too close to the dashboard in a crash, or should there be a child in the front seat, or should the front seat be empty. This Smart Airbag system also utilizes Autoliv's new technologies with less aggressive Gentle Airbags. The aim for Autoliv with this project has been to remove the remaining, very rare risks with current airbag systems without compromising their protective effect. Airbags have already saved some two thousand lives and prevented many more serious injuries. In addition, these numbers are bound to rise, as the number of airbag-equipped vehicles increases. (Currently, 30 percent of the cars on U.S. roads, and only 15 percent of the cars in Europe, have airbags, and most of the cars that have this safety device have it only for the driver). The downside, however, is that some 80 people are estimated to have been killed by deploying airbags. Virtually all of these occupants were unbelted, improperly belted, or children in -- often rear-facing -- child seats. This year, however, the number seems to go down, since "only" 13 fatalities have been reported in the U.S., so far compared to 29 cases for the full year 1996, despite the fact that there are 50 percent more cars on the U.S. roads with passenger airbags. But the need for action is nevertheless pressing. To address these problems, Autoliv has implemented a two-pronged development strategy. The first aim has been to minimize the deployment aggressivety of current airbags by several design changes. Although such a Gentle Bag is less aggressive than the so-called De-powered Airbags, it still fulfills FMVSS 208 requirements in the United States. Autoliv's first Gentle Bag initially deploys radially, before it approaches the occupant, preventing unbelted occupants from coming too close to the airbag before it is properly inflated. This improvement was presented earlier this year. A second design improvement is a gas generator that inflates in two steps, giving the bag time to unfold and the vent holes to be freed before the second inflation starts. Should the bag then encounter an occupant, any excessive gas -- and indeed bag pressure -- will exit through the vent holes. These improvements will not only be utilized in Gentle A airbag systems, but also in the Smart Airbag System Autoliv presented today. By combining the two improved systems, people will, of course, trust this solution more readily than an exclusively electronic alternative. But equally important is that the gentle bag improvements will reduce the number of cases in which the occupant is too close to the dashboard to make it safe to deploy the bag. A combined system can therefore save more lives and prevent more injuries than an intelligent system without a Gentle Airbag. Autoliv's Smart Airbag System will not only be able to determine if there is an occupant in the front seat and if there is a child, but it can also determine the distance between the occupant and the airbag and if the occupant is belted or not. If the occupant is too close to the dashboard in a crash, the sensor system will prevent deployment of the passenger airbag. Nor will the airbag be activated, of course, if the front seat is unoccupied, or if there is a rear-facing child seat. The advanced sensing system which Autoliv's Smart Airbag System uses, is developed by the U.S. company Automotive Technologies International (ATI), with which Autoliv has formed a joint venture for the commercialization of ATI's patents for Occupant Position Detector (OPD). The system uses four ultrasonic transducers, placed in the car around the passenger front seat. These "sonars" give a computer in the system a three-dimensional picture of any object or person in the seat. This three-dimensional picture is updated every 50 milliseconds, i.e. 20 times per second, to detect also an occupant who is being hurled forward in a panic braking immediately before a crash. Before the system can be used, the computer has to be "trained" to recognize all types of childseats and all conceivable positions of the occupant of various sizes, as well as special cases, such as an occupant holding a book or a newspaper in front of the airbag, the occupant being under a blanket or a coat etc. In total, the system is capable to differentiate between as many as 450,000 different configurations, which should cover all real world situations. Since the system is selfdiagnostic, it will also tell the driver if there is a malfunction. Based on tens of thousands of tests performed so far with the system, both the decision accuracy (how difficult it is to trick the system) and its reliability is well over 99 percent. After remaining evaluations by potential customers and fine-tuning of the system, which are expected to continue into next year, production preparations at Autoliv and its customers will take at least one year, and then the final introduction of the Smart Airbag System will be decided in cooperation with Autoliv's customers. SOURCE Autoliv, Inc.