180-degree arc position encoder with an extended angular position sensing range

摘要

This disclosure describes techniques for sensing an angular position of a rotating object over an angular position range that includes up to 360 degrees using an arc position encoder comprising a substantially 180-degree angular position sensing range. The encoder may include a base comprising an arc length defined by a first and a second end, one or more magnetic field sensors disposed within the base between the first and second ends, and one or more polarity transition sensors also disposed within the base between the first and second ends. The encoder may further include a magnetic target that includes first and second magnetic poles disposed on opposite ends so as to generate a uniform magnetic field, wherein the magnetic target is coupled to the rotating object so as to rotate about an axis of rotation located substantially in a center of a circle defined by the base.

主权项

1. An angular position sensing system for sensing an angular position of a rotating object over an angular position range that includes up to 360 degrees, the system comprising:
an arc position encoder comprising a substantially 180-degree angular position sensing range, wherein the arc position encoder includes:
a base comprising an arc length defined by a first end and a second end of the base;one or more magnetic field sensors disposed within the base between the first and second ends;one or more polarity transition sensors disposed within the base between the first and second ends; anda magnetic target comprising a first magnetic pole and a second magnetic pole disposed on opposite ends of the magnetic target so as to generate a uniform magnetic field, wherein the magnetic target is coupled to the rotating object so as to rotate about an axis of rotation located substantially in a center of a circle defined by the base, and wherein, at any given time, one of the first and second magnetic poles is located within the 180-degree angular position sensing range of the arc position encoder, and another one of the first and second magnetic poles is located outside of the 180-degree angular position sensing range.