About encoders and odometry
Odometry is measuring how a position has changed over time. We can combine measuring and estimation to determine where you are on a route. An encoder is a sensor designed to measure distance traveled via wheel turns. They are like tachometers, but encoders measure position whereas tachometers measure only speed. Combined with time, they can make a speed measurement too.
Absolute and relative sensing
Sensors for a robot’s location come in two primary forms. They are as follows:
- Absolute sensors encode a position to a repeatable position. They have a limited range or resolution, such as encoding a position along a known line. For example, GPS sensors have exact positioning with low resolution, suitable for meters but not millimeters.
- Relative sensors tend to be cheaper. However, they produce a relative change in position, which needs to be combined with the previous state to get an absolute estimate – this means that errors...
