In a closed-loop control system, which component provides the feedback signal?

In a closed-loop control system, which component provides the feedback signal?

• A. The reference setpoint
• B. The actuator
• C. The feedback sensor measuring output
• D. The input signal from the controller

Answer: (C)

The key idea is that a closed-loop control system relies on real-time information about what the plant is actually doing so the controller can correct any difference from the desired value. That information comes from the feedback sensor measuring the output and converting it into a signal the controller can use. With this feedback, the controller compares the measured output to the setpoint, computes the error, and adjusts the actuator’s input to drive the output toward the target. The other parts have different roles: the setpoint defines what you want, the actuator applies the needed effort to the plant, and the signal from the controller is the command to the actuator, not the measured response. The sensor’s job is essential because it closes the loop by providing the measured output that informs the controller how to respond.

The key idea is that a closed-loop control system relies on real-time information about what the plant is actually doing so the controller can correct any difference from the desired value. That information comes from the feedback sensor measuring the output and converting it into a signal the controller can use. With this feedback, the controller compares the measured output to the setpoint, computes the error, and adjusts the actuator’s input to drive the output toward the target.

The other parts have different roles: the setpoint defines what you want, the actuator applies the needed effort to the plant, and the signal from the controller is the command to the actuator, not the measured response. The sensor’s job is essential because it closes the loop by providing the measured output that informs the controller how to respond.