What is a gyroscope?
The gyroscope, or gyro, is a device that measures or maintains rotational motion. MEMS (microelectromechanical systems) gyros are small, inexpensive sensors for measuring angular velocity. Angular velocity units are measured in degrees per second (° / s) or revolutions per second (RPS). Angular velocity is simply a measure of rotational speed.
Gyroscopes, similar to the previous one, can be used to determine the orientation and are found in most autonomous navigation systems. For example, if you want to balance a robot, the gyroscope can be used to measure the rotation of the balanced position and send the corrections to a motor.
industrial electricity, electronics, gyroscope , sensor
How does a gyroscope work?
When an object rotates around an axis it gets something called angular velocity. A spinning wheel can be measured in revolutions per second (RPS) or degrees per second (° / s).
Imagine a wheel turns once a second. It would have an angular velocity of 360 degrees per second. The direction of rotation is also important. Is it clockwise, or is it counterclockwise?
A three-axis MEMS gyroscope can measure rotation about three axes: x, y, z. Some gyroscopes come in single- and dual-axis varieties, but the integrated circuit of the three-axis gyroscope is becoming smaller, cheaper, and more popular.
3 axis gyroscope
How does a gyroscope detect rotation?
When spun, a small mass moves as the angular velocity changes. This movement is converted into very low current electrical signals that can be amplified and read by a microcontroller.
How to select a gyroscope?
There are many specifications to consider when selecting a gyroscope. Here are some of the most important ones:
The measurement range, or full-scale range, is the maximum angular velocity that the gyroscope can read.
Sensitivity is measured in mV per degree per second (mV / ° / s). Don’t let the strange dimension of this value scare you. The amount of voltage changes for a given angular velocity is determined. For example, if you specify a gyroscope with a sensitivity of 30mV / ° / s and you see a change of 300mV at the output, this means that the gyroscope rotates at 10 ° / s.
As with any sensor, the values that are measured will contain a certain amount of error or bleed. You can see the shift by measuring the output when the gyroscope is static. Although you might think that 0 ° / s would be seen, you will always see a slight non-zero error in the output. These errors are sometimes called polarization shift. The sensor temperature greatly affects the error. To help minimize the source of this error, most gyroscopes have a built-in temperature sensor. Therefore, you are able to read the temperature of the sensor and correct any temperature or dependent changes. In order to correct these errors, the gyroscope must be calibrated. This is usually done by keeping the gyroscope still and zeroing out all the readings in the code.