Which statement about a control loop is true?

• A. It is a one-off, not repetitive.
• B. It consists of a number of repetitive steps that cause the robot to achieve a desired goal.
• C. It has no sensor input.
• D. It does not involve decisions.

Answer: (B)

At its heart, a control loop is a feedback process that continuously monitors the system, compares the current state to the desired target, and applies actions to reduce any error. The statement that best describes it says the loop consists of a number of repetitive steps that cause the robot to achieve a desired goal. In practice, a sensor reads the current state, a controller calculates an adjustment based on the difference between the setpoint and the measured state, and an actuator implements that adjustment. This cycle repeats, allowing the robot to reach and maintain the goal even in the presence of disturbances.

Saying it’s a one-off isn’t accurate because control loops are designed to run repeatedly over time. Claiming there’s no sensor input ignores the essential feedback that tells the system how it is performing. And stating there are no decisions overlooks the controller’s role in choosing the appropriate action based on the error signal.