In a controller of the present invention that controls a drive mechanism driven by a plurality of motors, when a state where the output of the motors is zero shifts to a state where the output is non-zero such that a preload torque is provided by a preload torque superimposition unit, at least one of the motors forms a contact portion between the drive mechanism and the motor by speed control based on a speed detection value detected in a speed detection unit, and in a state where the contact portion is formed, the preload torque is provided by the preload torque superimposition unit.