大象传媒

Professor Danielle George demonstrates what feedback loops are by asking a child to match the note that she plays on a swanee whistle. She explains how the child must listen to the note and adjust her hand accordingly, using the feedback from the note she hears to reach the right note. Danielle demonstrates a robot which follows a white line on a black surface by also using a feedback loop. The robot uses an infrared camera to detect the amount of light being reflected off the floor: if the reflection is high it means its positioned over the white tape, and so the robot moves forward, and if the reflection is low it means the robot has deviated from the tape and so the robot moves left or right to find the white tape again. This is an example of a simple feedback loop, as the robot uses the incoming information, and reacts to it, to remain on its course.