Okay, so imagine you have your toy car and you want to paint it. But you're not very good at painting, so you ask a robot to help you. This robot has special eyes called "sensors" that can see everything around it.
For the robot to paint your car, it needs to see where it should paint. So it uses sensors to look at your car and figure out where it needs to paint.
But painting is different from welding. Welding means melting two things together using very hot metal. So instead of painting, our robot needs to use a very special tool called a "welding torch".
Now, imagine you're a robot in a factory and there's a worker welding some metal parts together. You want to help but you don't want to burn yourself! So you have sensors that can "feel" how hot the metal is.
The sensors help the robot know how close it can come to the welding without getting burned. This means the robot can work safely and help the worker weld things faster and better.
So there you have it! Sensors for arc welding help robots see where they need to melt metal together, and "feel" how hot the metal is. This way, they can help workers weld things more safely and efficiently!