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US 7,804,210 B2Granted
Position measurement using magnetic fields
AssigneeBose Corporation
InventorsRichard F. O'Day, Dariusz Antoni Bushko
Life of this patent
Estimating the term…
Abstract
A position sensing system for positioning a linear motor that includes a stator and an armature having magnets, the armature moving relative to the stator along a path. A sensor determines a position of the armature based on measurements of a magnetic field generated by the magnets of the armature.
Claims23
An apparatus comprising:
- an armature of a linear motor comprising a series of magnets generating a magnetic field and defining a path having a first end and a second end, wherein the series of magnets comprises a first end magnet located at the first end;
- a stator of the linear motor comprising coils to interact with the magnetic field generated by the series of magnets of the armature to move the armature relative to the stator along the path;
- and
- a plurality of sensors located at fixed positions relative to the stator to sense at least a portion of the magnetic field that is generated by the first end magnet of the series of magnets to determine an absolute position of the armature relative to the stator throughout movement of the armature along the path between the first end and the second end.
1 more element
An active suspension system comprising:
- an armature of a linear motor comprising a series of magnets generating a magnetic field and defining a path having a first end and a second end, wherein the series of magnets comprises a first end magnet located at the first end;
- a stator of the linear motor comprising coils to interact with the magnetic field generated by the series of magnets of the armature to move the armature relative to the stator along the path;
- a plurality of sensors located at fixed positions relative to the stator to sense at least a portion of the magnetic field that is generated by the first end magnet of the series of magnets to determine an absolute position of the armature relative to the stator throughout movement of the armature along the path between the first end and the second end;
- and
- a controller to control the linear motor based on the position of the armature.
2 more elements
A method comprising:
- employing an interaction between coils of a stator of a linear motor with a magnetic field generated by a series of magnets of an armature of the linear motor to move the armature relative to the stator along a path defined by the series of magnets, wherein the path has a first end and a second end, and wherein the series of magnets comprises a first end magnet located at the first end;
- and
- employing a plurality of sensors located at fixed positions relative to the stator to sense at least a portion of the magnetic field that is generated by the first end magnet of the series of magnets to determine an absolute position of the armature relative to the stator throughout movement of the armature along the path between the first end and the second end.
An apparatus comprising:
- an armature of a linear motor comprising a series of magnets generating a magnetic field and defining a path having a first end and a second end, wherein the series of magnets comprises a first end magnet located at the first end;
- a stator of the linear motor comprising coils to interact with the magnetic field generated by the series of magnets of the armature to move the armature relative to the stator along the path;
- and
- a first plurality of sensors to measure the magnetic field generated by the series of magnets of the armature to provide a low resolution measurement of the absolute position of the armature with respect to the stator,
- a second plurality of field direction sensors to measure the magnetic field generated by the series of magnets of the armature to provide a high resolution measurement of the relative position of the armature with respect to the stator, and
- a processor to combine the low resolution measurement of absolute position of the armature with respect to the stator with the high resolution measurement of relative position of the armature with respect to the stator, to form a high resolution measurement of the absolute position of the armature with respect to the stator.
3 more elements
Dependencies are inferred from the claim text.