ABSOLUTE POSITION SENSOR USING HALL ARRAY

摘要

A system for determining an absolute position of a device includes a high resolution track, a sensor and processing unit associated with the high resolution track, a reference track having a plurality of pole pairs arranged to define a plurality of single-track Gray code segments, and an array of Hall effect sensors associated with the reference track to output a reference signal to the sensor and processing unit indicative of the coarse absolute position of the device over the Gray code segments. A third track has at least one pole pair. At least one sensor associated with the third track outputs a signal used to determine a location within one of the plurality of Gray code segments. The sensor and processing unit combines the third track signal, the reference signal, and the position of the device over the high resolution track to determine an initial, fine absolute position.