Patent ID: 6925401
Filing Date: 2005-08-02
Classification: G01D,H02P

Abstract:
1. A method for correcting a gain of an output signal produced from a resolver that detects a rotation of a rotary device, the method comprising: picking, for a certain time period, a maximal sine value and a minimal sine value from a sine output signal included in the output signal, and a maximal cosine value and a minimal cosine value from a cosine output signal included in the output signal; calculating a first differential value between the maximal sine value and the minimal sine value, and a second differential value between the maximal cosine value and the minimal cosine value; correcting a gain differential between the sine output signal and the cosine output signal based on the first and second differential values; and determining a candidate gain differential between the sine output signal and the cosine output signal based on the first and second differential values before the correcting, wherein the correcting is performed periodically or at a start of the method, and is inhibited when the candidate gain differential is out of a certain range.