SEPTEMBER 27--The night vision system that Autoliv Inc. (Stockholm, Sweden; www.autoliv.com), a developer of automotive-safety systems, offers with The BMW Group is based on existing infrared (IR) camera technologies. However, the original system has been redesigned, and the new camera system contains several innovations.
The environment in which a motor vehicle operates is taxing. Gravel roads or icy, salty winter streets, for instance, demand that the vehicle's equipment be very reliable and durable. The sophisticated IR camera technology must work without service and maintenance for the life of the vehicle, while IR cameras in other applications often have technical specialists checking them. The production volumes in the automotive industry are also significantly higher than in other markets for IR systems.
Particularly challenging for this development project has been the different commercial conditions in the automobile industry compared to traditional markets for IR cameras. As a result, not only the camera but also most of the components and the manufacturing technologies have been specially developed to meet the needs of the automotive industry. In cooperation with The BMW Group, Autoliv has identified these needs and formed a network of companies, each one with a key technology competence in the areas required for developing an affordable IR camera system in a larger production run. Autoliv has also built its own camera plant in Goleta, CA.
In addition, existing methods for producing the lens could not be used. Traditionally, lenses for IR cameras have been produced using a tedious mechanical single-point diamond-turning process. The need to find another manufacturing technology was complicated by the fact that IR camera lenses are typically made of germanium. Regular glass does not let IR radiation through. However, these obstacles have been overcome thanks to the Belgian company Umicore, a specialty materials group.
Umicore developed a new material with excellent IR-transmission properties called GASIR. This material is formed into a lens using a highly efficient molding technology. It took Umicore's French and English engineers more than six years to develop this innovative lens package and the manufacturing process. The lens package will be produced in a newly erected high-volume manufacturing facility in Quapaw, OK.
One new feature in the camera is a patented digital zoom-in/zoom-out function. Another new feature is the system for controlling the image brightness and contrast. These functions are set by the driver and then automatically adjusted for the variation in the scene temperature outside the vehicle and for other things affecting the IR image. In this way the driver is always provided the best possible image brightness and contrast, whether it is cold or warm outside, dusk or dawn.
In addition, to enhance the image quality of the camera, the resolution of the sensor in the camera has been increased, and the number of pixels is four times greater than in the original camera. This sensor, which is a bolometer, has been developed by FLIR's Indigo Systems, a manufacturer of IR cameras and IR sensors based in Portland, OR. FLIR will produce the bolometers at its Goleta plant in California, where the company has developed and introduced new automated manufacturing processes to cope with the higher volumes expected in the automotive industry.
Since a sensor with higher resolution provides more data, the electronics for the image processing had to be upgraded accordingly. In addition, Autoliv's experts in Sweden have designed an electronic control unit that controls the camera and provides the interface to the vehicle (see photo). They have also, together with Indigo Systems, been developing methods for processing the data from the camera to an image that the driver can see and understand.
For this project, Autoliv's engineers in Germany have been working with The BMW Group on the integration of the night vision system into its vehicles. BMW has decided to use its existing navigation system display to present the camera image to the driver. Much time and effort have been spent to find the optimal field of view for the displayed image. A wider field enables the driver to earlier detect animals and children who are approaching the road. However, a wider field of view makes pedestrians and objects smaller on the screen and thus less easy to quickly detect. To determine the best balance between these two goals, several comprehensive studies have been performed in driving simulators using students and drivers with a wide range of demographics.
For more information, contact Jan Carlson, Autoliv vice president engineering, at +46-8-587 20 656, or e-mail: [email protected], or Frank Schlöder, press and public relations, The BMW Group, at +49-89 383 20840 or e-mail: [email protected].