This one came to mind:
Class of 1999 (1990)
starring Bradley Gregg, Traci Lind, Malcolm McDowell, Stacy Keach, Pam Grier, John P. Ryan, Darren E. Burrows
IMDb synopsis:
Robot teachers have been secretly placed in the schools where the students have run riot. The teachers do a god job of controlling the unruly youngsters, until they go too far and some students get suspicious.
IMDb review:
It's the year 1999, and the violence in schools is virtually unstoppable, with many gangs contributing to the war zone look. To control this problem in a Seattle high school, a principal gets help from the Board of Government Educational Defense, and three disguised androids are sent. They are no ordinary robots that are there just to teach but have strong disciplinary actions to keep these savage students at bay. Soon, the punishment that these androids hand out becomes brutal and they decide to terminate the main problem by playing games on the students.
Director Mark L. Lester returns to provide us with a sequel to his cult classic "Class of 1984". This really isn't a direct sequel, and it's not up to scratch with the first. The original is basically far superior in every way. ... The robot designs were crafted with great detail and skill. Another notable thing that makes this worth a peek is the cast. Stacy Keach gives a deviously cheesy performance as the cynical Dr. Bob Forrest, the creator of these robots.
Here's the movie trailer:
http://www.youtube.com/watch?v=gHobJ7ipauw
There is a sequel: "Class of 1999 II: The Substitute". Here's the movie trailer:
http://www.youtube.com/watch?v=x4CGLf04Z44
Just for the heck of it, here's the movie trailer for "Class of 1984":
http://www.youtube.com/watch?v=N0JW8Aqftnc