| 摘要 |
PURPOSE:To judge occurrence of slip quickly and accurately by comparing the deceleration calculated based on the rotation of motor with the deceleration calculated based on the motor current. CONSTITUTION:Motor current iM is determined based on a signal fed from a current detector 11 then torque tauM is determined according to a motor current- torque characteristic stored in a ROM 15. Expected deceleration for the expected rotation N of a motor is determined according to formula (1), where tauR is the required torque and K is a constant. On the other hand, motor rotation (n) is detected based on a signal fed from a rotation sensor 9, then the motor rotation (n) is differentiated to produce a deceleration. If the deceleration is lower than an expected level during deceleration, it is judged that slip has occurred. |
