The Centurion Droids are an automated defense guarding the Vector Sigma supercomputer. Though possessing no weapons, Centurions are trained in hand-to-hand combat to stop all intruders. They also possess very strong armor that protects them from attacks, making them even more dangerous. They tend to be encountered in large numbers.
They must be either evaded or tricked in order for one to approach Vector Sigma. Fortunately, that's not hard.
The Centurion Droids were encountered by Optimus Prime again in the year 2011 when Prime was on another mission to reach Vector Sigma. However, this time around, the Centurions did not appear to be nearly as threatening, as Prime simply plowed through them like an American football player.
Greatly upgraded Centurion Droids were employed by Bludgeon and his crew to prevent disruption of their resurrection of Thunderwing and their study of the Pretender graft process. A squad of these droids managed to corner the Technobots Nosecone and Afterburner before being destroyed by the arriving Wreckers.
After the discovery that Thunderwing expended ultra energon more quickly the harder he was hit, Optimus Prime had Dogfight reprogram the remaining Centurions to attack the gigantic Decepticon. Attacking en masse, the Centurions managed to cause a massive spike in Thunderwing's internal catalytic flux, but they were quickly destroyed.