Abstract
Keywords
DSI (Distributed System Interface), Airbag ECU, Crash Recognition Algorithm, Time-To-Fire (TTF), Thresholding and zoning
Abstract
The DSI (Distributed System Interface) technology in the side satellite sensors of an airbag ECU which are applied to decide side collisions effectively has been studied recently for common and multiple uses. The side satellite sensor with DSI technology can interface to the two-wire DSI bus using a combination of pulse length encoded voltage levels for transmission of data to remote peripheral units, and can apply to the different vehicles with no software calibration. The DSI is intended as a robust serial interface system suitable for automotive body applications including airbag safety system. The new airbag ECU was set up with the airbag firing loop ICs with 6 channels (4 frontal channels and 2 side channels) for DC firing and firing loop monitoring, a micromachined capacitive accelerometer with a 2-pole Bessel 400Hz S/C filter, a multifunctional power supply IC, and the DSI digital and physical ICs. The applied MC9S12DJ256 microcontroller is the next generation of the higher performance and equips with a real time OS (Operation System) and a new crash recognition algorithm. The real time OS is observed the several functions as the internal and external fault diagnostic function, a communication function, and a crash history recording function. The time-to-fire of the airbag ECU is in qualitative agreement with the requirement time-to-fire of OEM vehicle maker. We have obtained the satisfactory results and wish to future study about an advanced airbag ECU using this technology.