| 摘要 |
PURPOSE:To obtain a good control system by performing oversampling and raising a sampling frequency. CONSTITUTION:An FG pulse having a frequency proportionate to a rotary frequency of a motor 9 is generated from an FG 1, and this period is converted into a digital value by a sampling circuit 2 and an FV converter 3, and then a difference from a target value is subtracted by a subtractor 4 to be as a speed error signal. This is added with a phase error signal by an adder 22 to be as a capstan error signal. This digital signal is converted into a pulse width modulation (PWM) signal, which is then turned into an analog signal through a low pass filter (LPF) 7, so as to be impressed upon a motor driver 8 to drive the motor 9. The sampling frequency is raised by an oversampling circuit 20 to a sampling frequency of a speed system, and a base band component and a frequency component of the sampling frequency after oversampling are only extracted by a filter 21, and are added with the speed error signal by the adder 22. By this method, a high speed, stable and good control system can be obtained. |
