| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a thrust ripple compensating arrangement of a linear motor capable of compensating a thrust ripple with precision and reducing variations in feeding a motor even if the thrust ripple of a linear motor contains a multi-cycle component with a low control gain. <P>SOLUTION: In the thrust ripple compensating arrangement of the linear motor, a thrust ripple compensation part 20 includes a phase calculator 25 in which a movable member position is input for outputting a phase of Fourier base wave, an operator 24 for outputting a Fourier transform function signal and a coefficient update function signal based on the movable member position, a Fourier transform unit 23 which, when the Fourier transform function signal becomes effective, performs Fourier transform based on the Fourier basic phase and compensation thrust command for calculating a first Fourier coefficient, a buffer 22 in which, when the coefficient update function signal becomes effective, the first Fourier coefficient is inputted to update data for outputting a second fourier coefficient, and an inverse Fourier transform unit 21 which performs inverse Fourier transform using the second Fourier coefficient based on the Fourier basic phase for calculating a ripple compensation value. <P>COPYRIGHT: (C)2010,JPO&INPIT |
