| 摘要 |
PROBLEM TO BE SOLVED: To reduce an offset calculation error in a transient state upon an offset calculation of an output signal from a position sensor in a position detection device, and to shorten an offset convergence time.SOLUTION: Measurement position signals AS and AC output from a position detection sensor 1 are converted to digital measurement position signals DS and DC, first-order digital lowpass filter processing is performed to the digital measurement position signals DS and DC and then, an offset calculation is performed. When the offset calculation of the digital measurement position signal DS is performed, as an initial value of a first-order digital lowpass filter 26, a value obtained by multiplying the digital measurement position signal DS and a ratio of a velocity of cutoff frequencies of the first-order digital lowpass filters 26 and 27 and a velocity to be calculated from a velocity converter 11 is employed, and when the offset calculation of the digital measurement signal DC is performed, as the initial value of the first-order digital lowpass filter 27, a value obtained by multiplying the digital measurement position signal DS and the ratio is employed, and thereby the offset calculation is performed. |
