Sensor
센서
A part that measures things like light, distance, force and tilt and tells the robot. It is the robot's sense organ.
Overview
A robot learns about the outside world and the state of its own body through sensors. Cameras see the surroundings like eyes, and lidar and radar measure the distance to objects. Sensors in the joints tell the robot what pose an arm is in now and how much force it is under.
Touch sensors in the fingertips feel whether an object is slipping, and tilt sensors inside the body are used to keep balance so the robot does not fall. A single sensor can be weak against rain, darkness or dust. So a common method is to combine information from several sensors so they fill in each other's gaps.
An everyday example
Just as a person sees with the eyes, feels with the fingertips and keeps balance with an organ in the inner ear, a robot does the same things with cameras, touch sensors and tilt sensors.
Why it matters
No matter how smart the AI is, a robot moves wrongly if its sensors measure wrongly. The price and safety of self-driving cars and robots depend a lot on which sensors they use and how many.