Compact Vibration Measuring System for in-vehicle Applications

Low frequency vibrations occurring in ground transportation are of interest in research of the driver's and the passenger's comfort and in seating dynamics research. Piezoelectric accelerometers commonly used for vibration measurement are not well suited for the analysed frequency range. Hence, other sensors capable of measuring accelerations down to the sub-Hertz region have to be used. MEMS acceleration sensors are particularly suitable for such purposes. A compact measuring system employing two three-axial MEMS accelerometers interfaced via a USB data acquisition unit to a laptop was designed and constructed. The digitised data were then processed by scripts in Matlab® with the aim of analysing both the effect of vibration on a seated person and the dynamic properties of the seat. Preliminary results of a test run with a passenger automobile are presented.