| 摘要 |
PROBLEM TO BE SOLVED: To remove offset errors, amplitude errors, phase errors, and tertiary harmonic components included in a two-phase sine wave-like signal by using relatively simple digital arithmetic processing. SOLUTION: The offset errors included in the two-phase sine wave-like signal, with its phases shifted, which are output from an encoder are detected and corrected (S12). Then, the amplitude errors included in the offset-corrected sine wave-like signal are detected and corrected (S13). Subsequently, the phase errors included in the amplitude-corrected sine wave-like signal are detected and corrected (S14). Further, tertiary harmonic distortions included in the phase-corrected sine wave-like signal are detected and corrected (S15). At the respective correction steps, an error included in the corrected sine wave-like signal from an ideal Lissajours waveform is detected. The detected errors are added to a value obtained by accumulation/addition in the past to find a new correction coefficient, thereby dynamically updating the correction coefficient. COPYRIGHT: (C)2006,JPO&NCIPI
|
