Patent ID: 8467942

Claim:
A gear drive controller that controls driving of a driving gear of gears meshing with each other including a backlash therebetween, the gear drive controller comprising: a backlash determination means that determines that the driving gear or a driven gear is rotating within the backlash when (i) an output torque of a drive source is smaller than an acceleration torque in idle running of the drive source with a first prescribed value added to the acceleration torque in idle running and (ii) an angular acceleration of the drive source is equal to or greater than a second prescribed value; a command value storage means that stores a command value for changing the output torque of the drive source; a torque limit setting means that, when it is determined that the driving gear or the driven gear is rotating within the backlash, sets a torque limit so as to limit the output torque of the drive source at a point of elimination of the backlash; and an output control means that controls the command value to gradually change so that the output torque of the drive source is gradually changed to an upper or lower limit after the backlash is eliminated.