Children's Books discussion

Freedom is a sci-fi novella set in Albuquerque, New Mexico. It has an age range of 8 upwards.
'The black visors of the robots made them seem even more emotionless than the other robots. They stood very close to Logan, almost touching him, holding their weapons. For the first time in his life Logan realized that he was seen as a threat.'
A robot civilization governs Earth. The only humans alive on the planet are a group of children and teenagers who are being raised in different robot families. Logan tries to find out where they have come from and what is going to happen to them. Can they escape? Why are there no other humans?