Which sensor is commonly used to measure wheel or joint position?

• A. Encoders
• B. Switch
• C. Microphone
• D. Altimeter

Answer: (A)

Measuring wheel or joint position relies on sensing the angle of rotation. Encoders are designed for this, converting rotation into an electrical signal that represents the angle or the amount of rotation. They come in two main flavors: incremental, which provide pulses as the shaft turns to track relative movement, and absolute, which give the exact position at any moment. This makes encoders ideal for feedback in robotics, enabling precise control of motion and accurate odometry. In contrast, a switch only gives a binary on/off signal, a microphone measures sound, and an altimeter measures altitude—none of which directly provide rotational position data. So encoders are the sensor most commonly used to measure wheel or joint position.