| CPC G01B 7/003 (2013.01) [G01D 5/145 (2013.01)] | 23 Claims |
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1. An absolute position measurement system, comprising:
a multipole magnet comprising alternating magnetic poles extending along a multipole extension direction, wherein the multipole magnet has a linear changing configuration relative to a linear path and the multipole magnet is configured to produce a magnetic field along the linear path; and
a magnetic sensor configured to move along the linear path,
wherein the magnetic sensor comprises a first sensor element arrangement configured to generate a first sensor signal in response to the magnetic field and a second sensor element arrangement configured to generate a second sensor signal in response to the magnetic field,
wherein, as the magnetic sensor moves along the linear path, the first sensor signal has a first sinusoidal waveform having a first linearly changing peak-to-peak amplitude and the second sensor signal has a second sinusoidal waveform having a second linearly changing peak-to-peak amplitude, wherein the second sinusoidal waveform is phase shifted with respect to the first sinusoidal waveform,
wherein the magnetic sensor further comprises a processing circuit configured to:
receive the first sensor signal and the second sensor signal,
calculate a polar coordinate based on the first sensor signal and the second sensor signal,
generate a radius set based on the polar coordinate,
calculate an absolute angle based on a radius included in the radius set, and
calculate an absolute position of the magnetic sensor based on the absolute angle.
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