| 摘要 |
PURPOSE:To accurately detect the speed in a low speed range by selecting whether an observer is used in response to a motor speed, thereby alleviating the load of a CPU. CONSTITUTION:After position information theta and a motor current I are input to an observer (presuming unit) 4, the information theta and a reference speed V are compared, and when the detected value is the prescribed speed or higher, the observer is not used, but the present speed is presumed by a pulse obtained by a position detector. The speed V is selected, for example, to 1,500 r.p.m., and when the detected speed is 1,500 r.p.m. or lower, the observer is used to accurately detect the speed at a low speed. |
