| 摘要 |
PURPOSE:To optimize processing conditions by providing a cutting load current calculator in a controller for a servo motor to be used for an NC machine tool, etc., and detecting a motor current corresponding only to a cutting load torque except a driving torque to be used for driving the machine tool. CONSTITUTION:A position command Pc and feedback speed information Pf by an encoder 3 are input to a position controller 5, and a motor speed command Vc is output. The command Vc and a speed feedback Vf obtained by a speed detector 4 are input to a speed controller 6, and a motor current command Ic is output. A direction of the Vf is discriminated by a constant term calculator 91 of a cutting load current calculator 9 to decide a symbol of a constant D0 during this period, a constant D1 is multiplied by the Vf by a proportional term calculator 92, the Vf is further differentiated by a differentiating term calculator 93, and multiplied by a constant K. Outputs of the calculators 91-93 are subtracted from a current feedback If obtained by a current detector 2 by an adder/subtracter 94, and a current value Im corresponding to a cutting torque is output. |
