Computing KS3/4: Feedback loops

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.

This clip is from The Royal Institute Christmas Lectures 2014.

Teacher Notes

Key Stage 3:

Could be used to introduce the concept of feedback in loops.

Students could be asked to use online visual programming software to program their own line-following robot.

Key Stage 4:

Students could be asked to discuss self-driven or autonomous cars. How soon will they be as common as smartphones are now?

Are autonomous cars safer than human driven cars? What are the advantages? How do autonomous vehicles stay on the road?

Students could design an algorithm for a self-driving vehicle.

Curriculum Notes

This topic appears in OCR, Edexcel, AQA, WJEC GCSE in England and Wales, CCEA GCSE in Northern Ireland and SQA National 5 in Scotland.

More from The Royal Institute Christmas Lectures 2014:

How does a digital camera work?
How LED screens work
How robots can work together in a swarm
The Mars Rover and autonomous navigation
Solving a Rubik's cube by smartphone
What can 3D printing be used for?
Touching virtual objects