When most people think of robots, they either think of hulking Terminators or the types of dumb industrial robots taking part in a future robot uprising. But there’s another class of robot that’s also gaining traction — social robots that cost less than $1,000 and are designed for the home. They are more WALL-E than Terminator, and are meant to be personal companions and even “one of the family.” For all the stories about the perils of artificial intelligence, these machines are strangely disarming.