| 摘要 |
PURPOSE:To digitize a current feedback circuit without measuring actually a current value by calculating with a detection signal from a photoelectric pulse encoder for detecting speed on the basis of a relation formula to thus calculate a current feedback signal. CONSTITUTION:When the torque coefficient of a motor 31 is represented by Kt, the inertial moment of a load is represented by J, a load braking coefficient is represented by R and a current feedback gain is represented by Fi, even if the feedback current value Ib is not actually detected, it can be calculated by a formula (1) using a pulse counted number omegaO of a period from a photoelectric pulse encoder 32. The number of pulses from the encoder 32 is counted by a counter 33 on the basis of the formula (1), the counted number of the n-th period and the counted number before one period are stored in an n-register 34 and (n-1) register 35, and the feedback current value Ib is calculated at every period. This calculated value is held in an H register 42 to be fed back to the current control loop. |
