How often should a robot check its motor encoder when using PID?

When using a PID (Proportional-Integral-Derivative) controller, the robot should check its motor encoder continuously while the motor is in operation. This is crucial because PID control requires real-time feedback to adjust the control signals sent to the motor. By consistently monitoring the encoder inputs, the PID algorithm can evaluate the current position or speed of the motor against the desired setpoint.

The continuous feedback allows the controller to make instantaneous corrections based on the difference between the desired state and the current state, known as the error. This real-time adjustment helps maintain accurate speed control and enhances the overall performance of the robot, making it responsive to any disturbances or changes in conditions.

Options suggesting checking the encoder at fixed intervals, such as once every second, or only at the beginning of a task, would not provide sufficient and timely feedback to the PID controller. Similarly, only checking when instructed by the user would not enable the automation critical for effective motor control. Hence, continuous monitoring is essential for achieving the desired performance in robotic applications using PID control.