摘要 |
PROBLEM TO BE SOLVED: To improve an angle control resolution without changing a resolution of an angle sensor in rotation angle tracking control of a motor for a rotational drive device for an observatory telescope at a fixed rotation speed, namely, in a fixed rotation angle change.SOLUTION: A target time (Ti) of arrival is set for angles (Pi) at a predetermined interval to be tracked, the angles at the predetermined interval are measured by an angle sensor, and a time (ti) of arrival at the angle (Pi) is measured by a timer. A target time (Ti+1) of arrival is updated and set for an angle (Pi+1) next to the angle (Pi) measured by the angle sensor, and updating is performed with a deviation between the present measured time (ti) of arrival and the next target time (Ti+1) of arrival. A rotation angle of a motor is successively controlled while defining the target time (Ti+1) of arrival at the next angle (Pi+1) as a target value. |