If you are anything like this Wookiee… you may have asked yourself this same question. Special thanks goes out to the internet (especially the Simpsons Wiki) and my Tapped-Out friend Vampryss for first sharing this info.
Robby the Automaton is directly related to the Springfield Knowledgeum which was introduced with Level 34.
According to the Simpsons Wiki (and I quote), “Robby the Automaton is a robot used to promote the Springfield Knowledgeum. He is brought to Edna Krabappel‘s class telling the students about the Knowledgeum. He was believed to speak and move by itself but Bart saw the man controlling the robot from outside the classroom. When Bart hit the man, the robot started strangling Skinner, much to the students fun.”
Robby first appeared in the Season 9 episode “This Little WIggy” (Ep. 18) and was voiced by Hank Azaria. Later in the series, it appears that Robby was turned in to a scrubbing robot by Professor Frink.
Hope this helps answer the question. TTFN tapperinos!