To smoothly rotate a servo motor, even if the arithmetic time of a position command value exceeds a calculation period.

This system is provided with motors 103a-103c for controlling the drive of an object to be controlled and realizing positioning, a command value calculation means which is driven by interrupting processing and calculates the position command value of the object to be controlled within a prescribed time for each interrupting processing by controlling the drive of the motors 103a-103c, a storage means 200 for storing the past position command value calculated by the command value calculation means, an arithmetic excess flag 402 for generating a detection signal indicating that the arithmetic operation of the present position command value to be calculated by the command value arithmetic means, based on the interrupting processing is invalid within the prescribed time, and a substitute command value arithmetic means for calculating the present position command value, based on past position command values 501 and 502 stored in the storage means 200, based on the detection signal of the calculation excess flag.