Method and system of detecting eccentricity and up/down movement of a code wheel of an optical encoder set

摘要

A system and method of measuring a rotational motion of a code wheel measures a rotational movement of the code wheel including an error component due to a non-rotational movement of the code wheel; measures the non-rotational movement of the code wheel; and produces an error-corrected measurement of the rotational movement of the code wheel by using the measured non-rotational movement of the code wheel to cancel the error component of the measured rotational movement of the code wheel. A signal can be produced indicating a need for maintenance when the non-rotational movement of the code wheel exceeds a threshold.