What is an encoder's role in a robotic system?

• A. To generate power for the motor
• B. To provide feedback on rotation or position for speed and position control.
• C. To measure battery charge
• D. To encode control signals for transmission

Answer: (B)

An encoder’s job is to provide feedback about rotation or position to enable speed and position control. It reads the motion of a motor shaft and translates it into signals the controller can use to know exactly how far and how fast the component has turned. This feedback lets the control system compare the actual motion to the desired motion and adjust the motor drive to keep performance precise, often using a closed-loop method like PID. Incremental encoders produce many pulses to measure velocity and relative position, while absolute encoders give a unique position value for each rotation.

Gauging power generation, battery charge, or encoding control signals for transmission aren’t roles of an encoder, so those functions aren’t what encoders provide.