All Robots are NOT AI's.
Artificial Intelligence assumes some form of intelligence, not just basic programming.
A robot going 'Beep beep beep' and just that, nothing else, is not an AI. It is just a robot.
Robots can be supplied with AI's to allow them to move about manually instead of digitally.
So while you can have 1 Billion robots lying around, AI's are meant to be incredibly complex.