All courses › Robotics › Encoders

Encoders

An encoder measures a robot joint's angular position. An incremental encoder counts pulses from a reference point and must be homed after every start-up, while an absolute encoder gives the angle directly, even right after a power loss, but costs more. The resolution of an absolute encoder depends on how many bits it has.

\Delta\theta=\dfrac{360^\circ}{2^n}

smallest angular resolution for an n-bit absolute encoder

Symbols

$n$	number of bits
$\Delta\theta$	angular resolution	°

Example

$n=12$ bits:

$\Delta\theta=360/2^{12}=360/4096\approx0.088°$ .

Incremental encoders must be homed after a power loss – absolute ones remember the angle directly.

Practise robot systems for free →

← Robot Configurations · Gearbox and Torque →

Part of Robotics: Robot systems.