Development of a Decision Making Algorithm for Airbag Control

,4bswct: Recently. many algorithms have been developed for airbag system to reduce head injury during the crash. Most of these algorithms are based on a single-point electronic accelerometer placed in the passenger compartment. This accelerometer is expected to overcome the limitations of the current distributed mechanical sensors which is costly and ineffective to trigger the airbag on time for different types of crashes. The electronic sensor is more effective in the sense that the signal from the accelerometer can he digitized and analyzed to study the behavior of the signal for different types of crashes. Unfortunately, most of the algorithms which are based on a single-point accelerometer still have several problems, they fail to trigger the airhag on time for several types of high speed crashes such as pole and angle crashes, or if they do trigger at these crashes they will also trigger at low speed barrier crashes [31,[5],[6]. Some of these algorithms study the tirst and second integral of the signal to get the change in vehicle velocity and the change in occupant position with respect to the car, other algorithms first filter the signal at a random low cutoff frequency and make different analyses [1],[4]. This paper presents a new algorithm for airbag control. In order to develop the algorithm first we analyzed the unfiltered accelerometer signal in time domain, then we studied the frequency response of the signal and analyzed its components and their effects on the signal. After that we studied the tiltered accelerometer signal in time domain, and finally we developed an algorithm based on our observation.