A robot controlling method for operating an arm using a motor includes: performing, before the arm stops, addition to add a backlash compensation value to a position command which is input to the motor; and performing, in a period during which the robot arm is not in motion, subtraction to reduce the backlash compensation value added to the position command.

A robot controlling method for operating an arm using a motor includes: performing, before the arm stops, addition to add a backlash compensation value to a position command which is input to the motor; and performing, in a period during which the robot arm is not in motion, subtraction to reduce the backlash compensation value added to the position command.

Provided are a control method and a control device that can make the range of periodic activity (amplitude of reciprocal movement) of an object of control, such as an industrial robot, the same as a case in which the reduction device has no backlash or the same as the amplitude of a position instruction signal. A control device (3) that carries out position control for an arm (5), which carries out periodic movement, while compensating for backlash in the arm (5) is provided with a control unit (15) that adds to a position instruction signal, which gives instructions for the position of the arm (5), a backlash quantity signal after the backlash quantity signal has been shifted so as to be delayed by a delay time, generates a final position instruction signal, and carries out position control of the arm (5) on the basis of the final position instruction signal that has been generated, said backlash quantity signal compensating for backlash.