Accelerometer: what is it, how does it work and what is it for
Even without working in the defense industry, you can have a general idea about the accelerometer: what it is, how it works and what parameters it has. After all, these devices are used in modern office equipment: laptops, tablets and phones. Have you ever wondered why your phone easily determines which is up and which is down when you twist it? This accelerometer allows the technique to "orient" in space.
General information
The accelerometer measures the projection of the apparent acceleration. Thanks to it, you can find out the difference between the absolute acceleration of an object and the acceleration of free fall.
The main classification of accelerometers is based on the number of axes involved. Accordingly, one can distinguish single-axis, two-axis and three-axis devices. The number of axes is also called the number of components. This parameter determines on what number of coordinates the accelerometer can measure acceleration.
Many accelerometers are combined with a data processing system, which allows you to create full-fledged sensors. After all, what is an accelerometer? This is a measuring device. Combine it with a computer, and the computing system is ready!
Application of accelerometers
Accelerometers are actively used in the design of navigation systems, along with gyroscopes. They are an integral element of the design of modern aircraft: airplanes, helicopters, missiles, drones.
In computer technology, accelerometers have become elements of hard drives, preventing vibration and damage. Having received a signal about a change in position in space, the device gives a command to park the hard drive heads in order to prevent scratches. Here it should be mentioned what a G-sensor is. In many ways, it is similar to an accelerometer and operates on the same principle. However, the compact size and functional features made it possible to integrate such a sensor into sensitive equipment: car recorders, tablet computers, communicators, and so on.
The sensor "knows" to distinguish between a sharp stop, turn, collision, rotation and other position changes. This is used both to protect equipment from damage, and for various programs and games that involve the position of the device in space. A few years ago, prototypes of modern G-sensors were already used in game consoles. Today, the accelerometer in a tablet can be used both for games and for serious programs, and in a phone, such a sensor allows you to determine which side to turn the screen to make it more convenient for the user to work and type.
As you might guess, an accelerometer or a G-sensor cannot work in zero gravity, so they will be completely useless and will not affect the device they are built into in any way.
Characteristics of accelerometers
The main characteristics that accelerometers have affect their functionality and, accordingly, their scope. Key parameters are:
- resolution (threshold sensitivity) – this is the name of the minimum change in the linear value that the device can fix;
- zero offset – instrument readings at apparent zero acceleration;
- random walk – the magnitude of the error, expressed through the average deviation from the zero offset;
- non-linearity is the change that will occur in the relationship between the output signal and the apparent acceleration if the apparent acceleration changes.
All these parameters should be taken into account when choosing any accelerometer, and, if possible, be interested in them when buying equipment that contains a G-sensor. Contrary to the stereotype, this will not be excessive meticulousness. You can choose a device that will not "fail" from random shocks and that will always correctly determine its position in space. This is especially true for the accelerometer in the phone, because phones have to quickly and clearly determine their position.