Which is a key advantage of closed-loop control?

• A. It can correct errors via feedback
• B. It avoids sensors entirely
• C. It eliminates all noise
• D. It guarantees zero steady-state error in all cases

Answer: (A)

Closed-loop control relies on feedback to correct errors by measuring the actual output and comparing it to the desired target, then adjusting the input to reduce the difference. This setup lets the system automatically compensate for disturbances, model inaccuracies, and parameter changes in real time. It does require sensors to monitor the output, so it doesn’t avoid sensors. Noise and disturbances can be mitigated but not completely eliminated, so you don’t get a perfectly noise-free signal in all situations. And while a well-designed closed-loop system can drive steady-state error toward zero for many cases, it can’t guarantee zero error in every scenario due to limits like saturation, nonlinearities, or unmodeled dynamics.