Servo Feedback

A type of automatic control system in which part of the output is fed back into the input to help control the action. In an automatic pilot system, an attitude sensor detects a wing dropping and generates an error signal that causes the servo to move the aileron down. A servo feedback signal is sent from the aileron to the attitude sensor, indicating that corrective action is being taken. The attitude sensor progressively cancels its error signal as the deflected aileron brings the wings back to a level attitude. By the time the wings are level, the error signal is eliminated and the aileron is no longer deflected.