ROTATION ANGLE DETECTION DEVICE FOR ROTATION DEGREE MEASUREMENT OF A TREE EXCEEDING 360

摘要

A rotation angle of a shaft is detected based on changes in levels of magnetic flux from a single magnet that is mounted on the shaft and is moved axially in accordance with rotation of the shaft. Respective detected variations in level of X-direction and Y-direction magnetic flux components (each at right angles to the shaft axis) are used to obtain a first quantity that varies monotonically, and a second quantity that varies periodically, in accordance with increased rotation angle. An accurate value of the shaft rotation angle is calculated based on the first and second quantities, in combination.