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For KidsWhat Robots Are

What Makes a Robot

A robot senses the world, decides with a program, and acts, over and over.

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A toaster has a heater and a timer. A remote-control car has motors and wheels. Are they robots? Most robot makers would say no. To be a robot, a machine has to do three jobs, over and over, on its own.

Key idea

A robot is a machine that senses the world, thinks with a program, and acts by moving or changing something. Then it senses again. Robot makers call this the sense, think, act loop.

Sense: a robot vacuum feels a bump. Think: its program says, "If I bump, back up and turn." Act: its wheels back up and turn. Then it senses again, many times each second.

Why it works

A remote-control car only does what your thumbs tell it. If you let go, it does nothing smart. A robot keeps checking and deciding for itself. That loop is what lets a robot vacuum clean a room while you eat breakfast.
Press Play. With its sensor on, the robot sees the wall and stops. Switch the sensor off and watch what happens.

Let's think it through

Worked example: Robot or not?

A night-light turns on by itself when the room gets dark. Is it a robot?
  1. Does it sense? Yes, it senses light.
  2. Does it think? A little: if dark, then on.
  3. Does it act by moving or changing the world? It only turns a light on. It never moves.

Answer: Most people would call it a smart machine, not a robot. It is close, though: it has a tiny sense, think, act loop.

Worked example: Robot or not?

A toy dog walks forward when you press its button, and keeps walking into the wall.
  1. Does it sense the wall? No.
  2. It does the same thing no matter what is in front of it.

Answer: Not a robot by our rule. It acts, but it does not sense or decide.

Common mistake

Thinking anything with motors and lights is a robot. Ask the three questions: does it sense, does it decide, does it act? A robot needs all three.

Try it at home: be the robot

Play a game. One person is the robot and wears a blindfold, in a clear, soft space with a grown-up watching. The robot may only sense by touch, with hands held out in front. The robot's program is: walk slowly; if your hands touch something, stop, turn right, and walk again. Everyone else is quiet. How does the robot do? What would a better program say?

For the grown-up. Clear the space of anything sharp or breakable and keep the robot walking slowly. This game teaches the sense, think, act loop better than any picture.

Practice

Pass with 3 right answers, the last 2 in a row. Each right answer earns 1 XP.

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Builds on

Nothing before it: a good place to start.

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