Accelerometers are integrated, built-in circuits or modules designed to precisely detect and respond to changes in acceleration, such as movement or vibrations. They measure the velocity change rate in an object, including gravity, rotation vector, linear acceleration, vibration frequency, etc. They are commonly measured in G-forces (g) or meters per second squared (m/s2).
Types of Motion Sensors – Accelerometers:
Three types of accelerometers are designed to work efficiently in their proposed environments, which are given below:
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Capacitive Accelerometer:
It is the most commonly used type of accelerometer that uses changes in electrical capacitance to determine the object's acceleration. As the sensor accelerates, the diaphragm shifts, causing a change in the spacing between its capacitor plates.
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Piezoelectric Accelerometer:
A piezoelectric accelerometer uses the piezoelectric effect to sense a change in acceleration. It is often used to measure shock and vibration.
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Piezoresistance Accelerometer:
Piezoresistive accelerometers are less sensitive than piezoelectric accelerometers and are more suitable for auto collision testing. They become more resistant by direct proportion to the pressure given to them.
How do they work?
These sensors are ideal for measuring static conditions such as gravity or dynamic forces (motion and vibration) during acceleration. The accelerometer can measure acceleration in units of up to three axes. These acceleration sensors generally comprise internal fixed capacitive plates, while some are attached to miniature springs. They move inward when the sensor generates acceleration energy. When these plates move, the capacitance of the plate changes, and by this change, we can determine the speed.
Typical Applications of Motion Sensors – Accelerometers:
These accelerometers are widely used in:
- Mobile devices
- Gaming systems
- Image stabilisation
- Disk drive protection
- Health and sports equipment
- Industrial and commercial applications.
