| 摘要 |
PROBLEM TO BE SOLVED: To reduce noise caused by the transient response of a piezoelectric device when a piezoelectric actuator is driven by servo-control. SOLUTION: In a servo-controller 1, the control signal (deviation signal) of a sampling frequency fs is generated from the input signal of a target position and the detection signal of the present position of a driven element 4 which is outputted by a drive unit 3. The control signal is transformed into the signal of a sampling frequency fp(>fs) by 0-order interpolation process. After high frequency components are eliminated from the signal by a filter circuit 204, a PWM signal is generated by using the signal as a modulation signal and, further, a drive pulse for driving a piezoelectric device 301 is generated in accordance with the PWM signal. The high frequency components of the drive pulse are eliminated from the drive pulse and level fluctuation is moderated to reduce the transient response of the piezoelectric device 301. |
