ME 3222
Controls and Kinematics Laboratory
Triggering an Airbag
Liam Pedroso, Lab Partner: John Nord
Section (003)
Background
The purpose of this experiment was to trigger an airbag through the motion of an accelerometer. Real airbags use
small mechanical sensors (not too different from the accelerometers used in lab) to trigger an electro chemical
reaction that inflated the airbag in milliseconds. In this lab we are using an LED as a indicator if the airbag would be
triggered.
Experimental Setup
Figure 1: schematic in Simulink that takes time and uses an if statement to trigger the LED.
Here the baseline was voltage was determined to be about 0.7 volts, and from there an if statement created
that generates the airbag response signal when the input voltage rises above that value.
Results
Figure 2: This is the baseline voltage data derived from the MEMS sensor this was used to set the initial voltage.
Figure 3: This is a plot showing the LED voltage spike as a response to the acceleration change.
Discussion and Conclusions
The relevant findings from the experiment are the rapid response to acceleration. The “airbag” triggers in less than
one hundredth of a second. The Simulink model was able to detect a difference between the baseline voltage and
respond with the output of the LED triggering. As seen in figure 3 the response to the subtle change in voltage leads
to a response in the LED voltage of +5 volts.
Appendix
Answers to the problems were completed on paper they are shown below.