Inductive displacement sensors

Patent metadata

Field	Value
Publication number	US-10564008-B2
Application number	US-201615542468-A
Country	US
Kind code	B2
Filing date	Jan 13, 2016
Priority date	Jan 13, 2015
Publication date	Feb 18, 2020
Grant date	Feb 18, 2020

Abstract

A transducer for an inductive displacement sensor includes a secondary winding of 2N turns of alternating directions extending in a zone of length Dtot, the winding including: a first coiled conductive section forming N half-turns, extending between a first end of the winding, situated at the midpoint of the length Dtot, and a first point of the winding, situated at one end of the length Dtot; a second section forming N half-turns, extending between the first point and a second intermediate point situated at the midpoint of the length Dtot; a third section forming N half-turns, extending between the second point and a third intermediate point situated at a second end of the length Dtot; and a fourth section forming N half-turns, extending between the third point and a second end of the winding situated at the midpoint of the length Dtot.

First claim

The invention claimed is:

1. A transducer for an inductive displacement sensor comprising
the transducer and a target suitable for moving according to a degree of freedom with respect to the transducer, the transducer comprising:
at least one primary winding; and
at least one first secondary winding extending in a zone of length Dtot parallel with said degree of freedom i.e. parallel with a direction x of displacement of the target with respect to the transducer, comprising 2N turns of alternating winding directions each having an edge of dimension approximately equal to Dtot/2N parallel with said degree of freedom, regularly distributed along the length Dtot, where N is an integer greater than or equal to 2,
and each of said at least one first secondary winding comprises:
a first coiled conductive section forming N half-turns, extending between a first end of the at least one first secondary winding, situated approximately at a midpoint of the length Dtot, and a first intermediate point of the at least one first secondary winding, situated at a first end of the length Dtot;
a second coiled conductive section forming N half-turns, complementary with the N half-turns of the first coiled conductive section, extending between the first intermediate point and a second intermediate point of the at least one first secondary winding, situated approximately at the midpoint of the length Dtot;
a third coiled conductive section forming N half-turns, extending between the second intermediate point and a third intermediate point of the at least one first secondary winding at a second end of the length Dtot; and
a fourth coiled conductive section forming N half-turns, complementary with the N half-turns of the third coiled conductive section, extending between the third intermediate point and a second end of the at least one first secondary winding situated approximately at the midpoint of the length Dtot; and
a first and a second connection terminals of the at least one first secondary winding respectively connected to the first and second ends of the at least one first secondary winding and a third access terminal of the at least one first secondary winding connected to the second intermediate point of the at least one first secondary winding.

2. The transducer for the inductive displacement sensor according to claim 1 , further comprising a differential measurement means, wherein the second intermediate point is referenced to an electric potential of the differential measurement means by said third access terminal.

3. The transducer for the inductive displacement sensor according to claim 2 , wherein the electric potential is a constant potential centered on a voltage measurement range of the differential measurement means.

4. The transducer for the inductive displacement sensor according to claim 1 , wherein the degree of freedom is a degree of freedom in translation along a rectilinear direction, and the length Dtot is a rectilinear linear length.

5. The transducer for the inductive displacement sensor according to claim 1 , wherein the degree of freedom is a degree of freedom in rotation about an axis, and the length Dtot is an angular length.

6. The transducer for the inductive displacement sensor claim 5 , wherein the length Dtot is equal to 360°.

7. The transducer for the inductive displacement sensor according to claim 1 , wherein each half-turn of the at least one first secondary winding has a U shape, straight or curved, and each turn of the at least one first secondary winding consists of two U-shaped half-turns of separate conductive sections, wherein vertical branches are oriented along opposite directions.

8. The transducer for the inductive displacement sensor according to claim 1 , wherein, in each turn of the at least one first secondary winding, turn portions orthogonal to the direction of displacement of the target with respect to the transducer are traversed twice by a wire or a conductive track of the at least one first secondary winding, and turn portions parallel with the direction of displacement of the target with respect to the transducer are traversed once by the wire or the conductive track of the at least one first secondary winding.

9. The transducer for the inductive displacement sensor according to claim 1 , further comprising at least one second secondary winding identical to the at least one first secondary winding and offset, viewed from the front, with respect to the at least one first secondary winding, the at least one first and second secondary windings being formed in first and second overlaid metallization levels, such that, for each secondary winding, a length of conductive track arranged in the first metallization level is approximately equal to a length of conductive track of the secondary winding arranged in the second metallization level.

10. The transducer for the inductive displacement sensor according to claim 9 , wherein, in each of the first and second secondary windings, a change of metallization level occurs every L/2 meters of conductive track, where L denotes length of a turn of the first and second secondary winding.

11. The transducer for the inductive displacement sensor according to claim 9 , wherein k changes of metallization level occur every L/2 meters of conductive track, where L denotes the length of the turn of the first and second secondary winding and k is an integer greater than or equal to 2.

12. The transducer for the inductive displacement sensor according to claim 1 , wherein N is an even number.

13. The transducer for the inductive displacement sensor according to claim 1 , wherein at least the at least one first secondary winding comprises filling patterns of vias and tracks with no wanted signal pickup function.

14. A transducer for an inductive displacement sensor comprising the transducer and a target suitable for moving according to a degree of freedom with respect to the transducer, the transducer comprising:
a primary winding; and
a first secondary winding extending in a zone of length Dtot parallel with said degree of freedom i.e. parallel with a direction x of displacement of the target with respect to the transducer, comprising 2N turns of alternating winding directions each having an edge of dimension approximately equal to Dtot/2N parallel with said degree of freedom, regularly distributed along the length Dtot, where N is an integer greater than or equal to 2,
wherein said first secondary winding comprises:
a first coiled conductive section forming N half-turns, extending between a first end of the first secondary winding, situated approximately at a midpoint of the length Dtot, and a first intermediate point of the first secondary winding, situated at a first end of the length Dtot;
a second coiled conductive section forming N half-turns, complementary with the N half-turns of the first coiled conductive section, extending between the first intermediate point and a second intermediate point of the first secondary winding, situated approximately at the midpoint of the length Dtot;
a third coiled conductive section forming N half-turns, extending between the second intermediate point and a third intermediate point of the first secondary winding at a second end of the length Dtot;
a fourth coiled conductive section forming N half-turns, complementary with the N half-turns of the third coiled conductive section, extending between the third intermediate point and a second end of the first secondary winding situated approximately at the midpoint of the length Dtot; and
a first and a second connection terminals of the first secondary winding respectively connected to

Assignees

• Hutchinson

Inventors

• Maniouloux Yohan
• Regache Pascal

Classifications

• G01D5/2046 Primary

  by a movable ferromagnetic element, e.g. a core · CPC title

• G01D5/2053 Primary

  by a movable non-ferromagnetic conductive element · CPC title

• G01B7/003

  for measuring position, not involving coordinate determination (coordinate measuring G01B7/004) · CPC title

• G01P3/49

  using eddy currents · CPC title

• G01P3/505

  by using eddy currents · CPC title