Accelerometer sensor is capable for a vast range of sensing.A sensor is a device which detects or measures a physical property, records it, indicates it, or otherwise respond on it.In sensor technology accelerometer sensor is a big innovation.Accelerometers sensor can measure acceleration in one, two, or three orthogonal axes.
- Accelerometer can intertial measurement of velocity and position;
- Accelerometer sensor of inclination, tilt, or orientation in 2 or 3 dimensions, as referenced from the acceleration of gravity.
- Accelerometer sensor can respond on vibration or impact (shock).
Working of Accelerometer
Accelerometers are small size and mechanical sensors, so it is known as Micro-Electro-Mechanical Sensors (MEMS). The basic principle of working behind the accelerometer is very simple. Accelerometer displace a small proof mass etched into the silicon surface of the integrated circuit ( IC )and suspended by small beams. According to Newton’s second law of motion (F = ma), as an acceleration is applied to the device, a force develops which displaces the mass. The support beams act as a spring, and the fluid (mostly air) trapped inside the IC acts as a damper, resulting in a second order lumped physical system.
Types of Accelerometer
Capacitive Accelerometer: Accelerometers is implemented for capacitive sensing output when a voltage dependent on the distance between two planar surfaces. Accelerometer capacitive sensing technology isbased on capacitive coupling, that takes human body capacitance as input.Accelerometer Capacitive sensors detect anything that is conductive or has a dielectric different from that of air.
Piezoelectric:The word “Piezoelectric” is made from the Greek word “piezein”which means press, and the word ” piezo”, which is Greek for “push”. Piezoelectric sensing of acceleration is natural, as acceleration is directly proportional to force. A piezoelectric sensor type accelerometer is a device that uses the piezoelectric effect, to measure changes in pressure, acceleration, strain or force by converting them to an electrical charge. Piezoelectric Effect is the ability of some materials to generate an electric charge in respond on applied mechanical stress.
Uses of Accelerometer sensors
This type of sensor can be implemented in wide range of devices like smartphones, gadgets, electronic cycles etc. for detects velocity, position, shock, vibration, or the acceleration of gravity to determine orientation Accelerometer is also useful for the detection of pen angles etc.
As a shock detector, this type of sensor is looking for changes in acceleration. This jerk is sensed as an overdamped vibration.