In side crashes, restraint systems like sidebags and pretensioners are controlled by digital algorithms. Presently, the inputs for these algorithms mainly come from acceleration sensors. Due to the small distances between occupants and inner car structure, the required fire times for optimal occupant protection are very small (5 to 10 ms). It is common practice to fulfil these requirements by continuously improving the acceleration based sensing. This paper presents the system enhancements offered by the sensing of the pressure inside the door cavity. The development of the sensing element is presented and some of its advantages and properties are pointed out. The main system features like the mechanical concept, the self test modes, the signal processing of the sensor, the interface and the climatic requirements are discussed. For the covering abstract see ITRD E126782.
Abstract