What is the main role of an encoder in robotics?

The main role of an encoder in robotics is to measure the position, speed, or direction of a motor shaft, making option B the correct choice. Encoders are essential in feedback systems within robotic applications, providing precise measurements that allow a control system to determine the current state of a motor. This information is critical for tasks such as positioning, navigating, and controlling the velocity of robotic movements, enabling the system to respond accurately to commands.

In closed-loop control systems, the encoder's feedback is used to adjust the motor's operation to achieve desired performance, ensuring that the robot moves accurately and efficiently. This position and speed data is fundamental for applications ranging from industrial automation to mobile robotics.

The other options do not accurately reflect the primary function of an encoder. While motor power output is important, it does not relate to the encoder's purpose, which is about measurement rather than power management. Wireless communication is not a function of encoders; they work with wired connections to transmit positional data. Similarly, data storage is unrelated to the function of an encoder, as its role is focused on real-time measurement rather than data retention or logging.