| 摘要 |
PURPOSE:To accurately calculate the optimum value of the time constant of a speed control system by sampling the output of a period measuring circuit after the lapse of time of 1/4 of the set value from when the output of the measuring circuit becomes equal to the set value. CONSTITUTION:When a sinusoidal speed command Nref is outputted, a motor 13 rotates at a speed Nref. At this time, the period tau of the output of a resolver 14 excited by a frequency f0 is obtained by a zero cross interval counter 16. A microcomputer 11' calculates the speed N of the motor 13 from the period tau. A comparator 17 outputs a drive signal when the period tau becomes equal to the period tau0 corresponding to the speed 0 of the motor 13. A timer 18 outputs an interrupt signal when 1/4 of period is elapsed from the variation in the speed from when a drive signal is applied. A microcomputer 11' calculates the speed N of the motor 13 by an interrupt signal, and the time constant of the speed control system is calculated by the value being obtained. |
