US 12,449,281 B2
Contactless position sensor comprising a permanent magnet
Richard Arlot, Bonnevent-Velloreille (FR)
Assigned to Absolute Magnetics AG, Bühler (CH)
Appl. No. 18/261,382
Filed by Absolute Magnetics AG, Bühler (CH)
PCT Filed Jan. 6, 2022, PCT No. PCT/FR2022/050028
§ 371(c)(1), (2) Date Jul. 13, 2023,
PCT Pub. No. WO2022/152996, PCT Pub. Date Jul. 21, 2022.
Claims priority of application No. 2100365 (FR), filed on Jan. 14, 2021.
Prior Publication US 2024/0068840 A1, Feb. 29, 2024
Int. Cl. G01D 5/14 (2006.01); G01R 33/09 (2006.01)
CPC G01D 5/145 (2013.01) [G01R 33/091 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A contactless position sensor, comprising:
a permanent magnet generating a magnetic field, the permanent magnet being able to move in a movement direction and having a continuously variable magnetization along the movement direction, a variation in the continuously variable magnetization having, according to different field components, a shape corresponding to a combination of at least two different quasi-periodic contributions; and
at least one detection element of the magnetic field in at least two directions; and
a computer configured to combine values of the field components and to determine a precise position value;
wherein the magnetization varies with a carrier frequency of period p*n, where n is a real number greater than zero that is constant or variable on an excursion, a measurement of the magnetization determines a rough position, and at least one secondary signal carried by lower period p provides a signal whose processing provides a fine measurement of the position.