Sensors
Science FactSensors are a robot's eyes, ears and sense of touch. They turn things in the world into electrical signals a computer can understand.
From the world to a signal
Every sensor changes something physical (light, sound, heat, pressure, movement) into a changing voltage. The robot's brain measures that voltage and turns it into a number, like 'obstacle 42 cm away'.
Light sensors and cameras
A camera sensor has millions of pixels that each measure how much light hits them. Software looks for patterns to find edges, colors or faces. Cameras need light, so they struggle in the dark.
Echoes: ultrasonic and LiDAR
Ultrasonic sensors send out high-pitched sound and time the echo, just like bats. LiDAR does the same with laser light, which is much faster and more precise, so it can build a detailed 3D map.
Sensor fusion
Every sensor has weaknesses: cameras hate darkness, ultrasonic sensors miss soft objects, LiDAR gets confused by glass. Engineers combine several sensors so one covers another's blind spots. This is called sensor fusion.
- World (light, sound)
- Sensor
- Electrical signal
- Number in the brain
- Decision
COOL REAL FACTS
- Your phone has an accelerometer, gyroscope, compass, light sensor and more.
- Self-driving cars can combine cameras, radar and LiDAR.
- Light from a LiDAR pulse travels about 30 cm in one billionth of a second.
SCIENCE FACT vs SCI-FI
Sensors that see through walls or read minds are fiction. Real sensors measure light, sound, heat, motion and pressure.
TRY IT (SAFELY!)
Clap near a wall far away and listen for the echo. Count how long it takes: sound travels about 343 metres per second.
REAL ENGINEER TIP
Engineers test sensors in the worst conditions: dark rooms, shiny floors, noisy places.
PARTS THAT USE THIS IDEA
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