| 摘要 |
A motor control apparatus (6d) and a method according to the invention are directed to detecting a motor velocity. Leading and trailing edges of two pulse signals are distinctively detected from one another, and those pulse signals have cycles which are proportional to the motor velocity, and a phase difference between the pulse signals is about one quarter of a single cycle from one another. Then, a period of time between the pulse edges in the same direction of the same pulse signal is measured, and the period of time between the pulse edges is used to sequentially convert it into the motor velocity and thereby detect the motor velocity. The motor control apparatus has a reverse rotation detector (6q) detecting if, upon actuation by the motor (1), reverse rotations are caused in an attachment unit (65) where an encoder (13) is attached, from output pulses from the encoder rotated by rotations of the motor, a first pulse counter (6r) counting edges of the output pulses from the encoder after the attachment unit has rotated from a reverse direction to a normal direction when the reverse rotations are caused in the attachment unit, to give a start command when a count value reaches a first specified value, and a speed calculator (6d) receiving the start command when the reverse rotations are caused in the attachment unit, to compute the motor velocity from the output pulses from the encoder. <IMAGE> |
