| 摘要 |
<p>A controller for controlling a plurality of hoists in an elevator has a rotation-speed and magnetic-pole-position-in-rotation estimating part for estimating the rotation speed and the magnetic pole position in rotation of each motor. If a cage is driven while one of encoders fails, only the motor of the hoist equipped with a normal encoder is driven in a low speed region at a predetermined or lower rotation speed. The motor of the hoist equipped with the normal encoder is driven and also the motor of the hoist equipped with a failing encoder is driven based on an estimation value by the rotation-speed and magnetic-pole-position-in-rotation estimating part out of the low speed region faster than the predetermined rotation speed.</p> |
