| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem that when a load on a spindle is high, a slip occurs between the spindle and a motor and the use of a spindle position detection result for motor speed feedback control results in unstable motor speed control. <P>SOLUTION: A control device includes: a speed control section for outputting a current command value in accordance with a position command value; a current detection section for detecting a current flowing to a motor; a first speed estimation section for estimating a first speed of the motor according to the current; a second speed estimation section for estimating a second speed of the motor according to a spindle speed calculated from a spindle position detected by a sensor disposed near a spindle and a speed ratio; and a load computation section for calculating a value of motor load. The speed control section calculates the current command value with the use of the first speed when the motor load value is a predetermined value or greater, and calculates the current command value with the use of the second speed when the motor load value is below the predetermined value. <P>COPYRIGHT: (C)2013,JPO&INPIT |
