Why Do Robots Use GPS Outdoors but Not Inside?

What Crafty Clover says in this video

Intro

Hi there, curious minds! I'm Crafty Clover! Let's discover something amazing. Why do robots use GPS outdoors but not inside?

The Big Idea

Robots use GPS outdoors because it listens to signals from satellites high above Earth! The signals are very weak, since they travel a long way. Walls and roofs block or weaken them, so GPS struggles inside.

Satellite Signals

Step one: satellite signals. GPS stands for Global Positioning System. Satellites high above Earth send out very weak radio signals, and a robot listens for them with an antenna.

Find Position

Step two: find your position. Outside, a robot can pick up several satellites at once. By comparing how long their signals took to arrive, it works out exactly where it is, often within a few meters.

Inside Instead

Step three: inside, use other tools. Walls and roofs block or weaken the signals. So indoor robots use cameras, lidar, and wheel counts to know where they are, and they build maps of the rooms as they go.

A Closer Look

Let's take a closer look! Satellites orbit far above, thousands of miles up. They send tiny radio signals down. Buildings can block them. And when enough signals arrive, the robot finds its position.

Quick Facts

Quick facts! Even outdoors, tall buildings can block GPS. Phones, delivery drones, and farm robots all use it. GPS can be off by a few meters, so robots add other sensors to be more accurate. Ask a grown-up before using phone maps outside.

Think Like a Scientist

Now, take the challenge! With a grown-up, open a map app on a phone outside, then inside the middle of a building. Watch the blue dot. Is the dot steady outside? Does it stay in the right place? What happens inside?

Outro

GPS likes open sky. Science is amazing! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!