The car is a symbolic tool in our modern, high-speed lifestyle and the research of its safety became high priority of the last motorized decades. In the present days, the development of the vehicle’s active and passive safety systems have raised a huge industry. In the accessories and optional equipment dotted new passenger car market, the vehicle’s airbag and belt tensioner equipments is a key quality, as well as the Euro NCAP crash test results.
In my thesis, which I made in co-operation with Robert Bosch Ltd. I was working with sensor signals of airbag and belt tensioner devices, including analysis of signal separation’s aspects. I also presented the method of ECU calibration using these signals.
In the first part (Chapter 3) concepts associated with the active and passive safety systems are briefly defined and the structure and function of airbag systems are introduced. In addition the Euro NCAP, U.S. NCAP crash test standards and the calibration process are presented through the calibration add on functions.
The second part (Chapter 4) gives a general overview of the basic concepts of an off-line signal analysis of a zero and non-zero initial acceleration approximation procedure of the acceleration signals (ASW, ESW, TESW approximation, etc...).
In the third part (Chapter 5) the previously shown approximations are applied in the examination of the offline signal separation of the sensor acceleration signals. Real crash test signals for different car models are compared in terms of the calculated parameters. The chapter aims to forecast the usability of these add on functions, affecting the results, duration, and effectiveness of the calibration process. In the end of this chapter the results are summarized.
In the fourth part (Chapter 6) a specific car model’s ECU calibration is introduced, based on the “three-threshold method" developed by myself. The advantages and the difficulties of the method are presented as well, and further development potential is discussed.