A Far Infrared Thermal Imager for Occupant Size and Position Sensing 2004-01-0836
This paper describes the work being undertaken jointly by QinetiQ and First Technology to develop a low cost thermal sensor to help vehicle manufacturers meet the smart airbag regulations being introduced by NHTSA.
The sensor is based on technology developed by QinetiQ and licensed to First Technology. It is a resistance bolometer that is sensitive to energy in the 8μm - 14μm waveband. An image is constructed and then image processing is performed to classify the occupants and determine their position. This information will then be available to the airbag system to assist in the deployment decision.
This paper outlines the requirements for the sensor and trial work to address the feasibility of using a thermal sensor in the automotive cabin environment. In particular, it addresses the effects of background temperature, occupant clothing, contamination and obscuration of the lens of the sensor.
Briefly, the key advantages of this thermal sensor are: passive sensing, providing an image regardless of illumination conditions without shadows or modulated light though the windshield, and low resolution requirements resulting in reduced quantities of data on which image processing must be performed.
Additional functionality has been considered for the sensor, principally as an input to the HVAC system or as an intruder detector.
