For example, among the first smartphones to make use of it was Apple's iPhone 3GS with the introduction of such features as the compass app and shake to undo, according to Wired.Ī gyroscope would be used in an aircraft to help in indicating the rate of rotation around the aircraft roll axis. Ultimately, an accelerometer cannot be used alone to assist in keeping aircrafts properly oriented.Īccelerometers instead find use in a variety of consumer electronic items. In an aircraft performing a 60-degree angle of bank for a turn, a three-axis accelerometer would register a 2-G vertical acceleration, ignoring the tilt entirely.
For example, in a free fall, the accelerometer would show zero acceleration. However, once that platform begins moving, its readings become more complicated to interpret. Accelerometers are used to determine acceleration, though a three-axis accelerometer could identify the orientation of a platform relative to the Earth's surface. Real-world usage best illustrates the differences between these sensors. In recent years, its application among consumer electronics extends now to personal laptops. Determining screen orientation, acting as a compass and undoing actions by simply shaking the smartphone are a few basic functions that rely on the presence of an accelerometer. The appearance of the accelerometer in the consumer electronics market, with the introduction of such widespread devices like the iPhone using it for the built-in compass app, has facilitated its overall popularity in all avenues of software. Accelerometers are equally widespread in use and can be found in engineering, machinery, hardware monitoring, building and structural monitoring, navigation, transport and even consumer electronics. A gyroscope, for example, is used in navigation on unmanned aerial vehicles, compasses and large boats, ultimately assisting with stability in navigation. The applications of each device vary quite drastically despite their similar purpose. In comparison, a gyroscope is intended to determine an angular position based on the principle of rigidity of space. The typical two-axis accelerometer gives users a direction of gravity in an aircraft, smartphone, car or other device. In comparison, the accelerometer measures linear acceleration based on vibration. Using the key principles of angular momentum, the gyroscope helps indicate orientation. When gauging the rate of rotation around the roll axis of an aircraft, it identifies an actual value until the object stabilizes out. The gyroscope maintains its level of effectiveness by being able to measure the rate of rotation around a particular axis. If you were to consider this handicap when used in an aircraft, the accelerometer quickly loses much of its appeal. When accelerating in a particular direction, the accelerometer is unable to distinguish between that and the acceleration provided through Earth's gravitational pull. In a way, the accelerometer can gauge the orientation of a stationary item with relation to Earth's surface. The main difference between the two devices is simple: one can sense rotation, whereas the other cannot. The first accelerometer was called the Atwood machine and was invented by the English physicist George Atwood in 1783, according to the book "Practical MEMS," by Ville Kaajakari.