To eliminate a system error generated from a time delay required from calculating and supplying a compensation signal.

A compensation signal is supplied simultaneously with and/or in the same clock cycle of the occurrence of a disturbance causing a motion requiring a compensation. An apparatus instruction logic circuit 11 generates a through instruction controlling a positioning of an apparatus. A positioning control system 14 positions the apparatus in response to the through instruction. A logic circuit 12 compensating space vehicle motion processes the through instruction provided from the apparatus instruction logic circuit, and responds to a signal representing the occurrence time of the disturbance, thereby causing the motion requiring the compensation. The logic circuit compensating space vehicle motion sends the compensation signal to the position control system almost simultaneously with the occurrence of the disturbance for compensating the disturbance. A time of a disturbance which will occur in the future, and cause a motion requiring a compensation is determined. Then, a compensation signal compensating the disturbance is calculated, and the compensation signal is provided for the apparatus at an occurrence time of the disturbance causing the motion requiring the compensation.