Multifunctional Shock, Tilt and Motion Sensor Based on MEMS Accelerometer

MEMS sensors are widely used in automotive security and anti-theft systems for detecting impacts, body tilts and vehicle movement. It should be noted that scientific publications on the subject of calculation and design of such sensors, due to know-how, are practically absent. In the paper under consideration, the results of experimental studies of accelerations acting upon impact, tilt and movement of the car are presented. For measurements, we used the STMDISCOVERY evaluation board with an LSM303DLHS MEMS accelerometer. The analysis of the level of noise and acceleration of vibrations when the board is attached to the plastic panel of the car is carried out. The measurements were carried out both at idle speed of the engine and while driving. Realizations of accelerations are given for: weak impacts in different parts of the car body (fender, trunk, hood); strong impact (sharp closing the door); slow and fast acceleration to a speed of 20 km / h, followed by braking. As a result of the research, the choice of the range of the accelerometer, the accuracy of measuring the acceleration and the sampling frequency of the signal is substantiated. Recommendations on the choice of MEMS accelerometers are given and some issues of technical implementation MEMS sensors for car security systems are discussed.