Accelerometers are devices that measure acceleration due to the gravitational pull of the Earth. These measurements can be used to determine motion and tilt of any object that the accelerometer is attached to.
There are three main types of accelerometer sensor, which are all manufactured with different technologies:
Capacitive accelerometers use capacitors with plates that move with changes in acceleration, and the distance between the plates affects their capacitance value.
Piezoelectric accelerometers make use of the piezoelectric effect to sense the change in acceleration, and are constructed from materials that produce a voltage in proportion to the force exerted upon them.
Piezoresistive accelerometers change their resistance according to the size of the acceleration force.
Accelerometers are commonly manufactured using a technology known as MEMS (microelectromechanical systems), which uses miniaturized structures ranging in size from several millimeters to less than a micrometer. Advancements in MEMS accelerometer technology has seen them increasingly used in military and defense applications that were previously dominated by macro-scale electromechanical accelerometer technologies.
Military Accelerometer Applications
Accelerometers are commonly used for measuring the power of explosions, and have been incorporated into soldier-worn and armored vehicle-mounted devices that can quantify the effects of explosive forces. They are also used for testing munitions such as missiles. Such accelerometers need to be extremely rugged and capable of measuring a wide range of g-forces.
Rugged accelerometers are also used to measure levels of shock and vibration, and may be used for testing the effects of firing guns and weapons platforms, as well as vehicles such as tanks and armored personnel carriers moving over rough terrain.
Inertial measurement units (IMUs) and inertial navigation systems (INS) utilize accelerometers as a key component. These devices are used to provide functions such as flight stability and enhanced navigation for aircraft, missiles, UAVs (unmanned aerial vehicles) and unmanned systems.