What is the difference between open-loop and closed-loop control?

The difference between open-loop and closed-loop control systems fundamentally lies in the use of feedback. In open-loop control systems, the output does not influence the control action; these systems operate on predetermined instructions without taking the current state of the system into account. This means that they do not utilize feedback to adjust their operation based on the output.

In contrast, closed-loop control systems incorporate feedback mechanisms that allow them to continuously monitor the output and make adjustments accordingly. This feedback loop helps the system to correct any errors or deviations from the desired performance by actively comparing the actual output to the set point and making necessary adjustments to the control inputs.

Understanding this distinction is crucial, as the presence of feedback in closed-loop systems usually leads to improved accuracy and stability in maintaining the desired output conditions compared to open-loop systems.