Analog sensor for contact-free angular offset sensing

• US 20020158627A1
• Filed: 07/02/2001
• Published: 10/31/2002
• Est. Priority Date: 12/01/1999
• Status: Active Grant

• Current Assignee: Continental Automotive GmbH (Continental AG)
• Original Assignee: Continental Automotive GmbH (Continental AG)
• Inventors: Jansseune, Luc, Dordet, Yves, Genot, Bernard
• Granted Patent: US 6,653,828 B2
• Time in Patent Office: Days
• US Class Current: 324/207.25
• CPC Class Codes: B62D 15/02 Steering position indicators ; Steering position determination; Steering aids
• CPC Class Codes: G01D 5/2033 controlling the saturation of a magnetic circuit by means of a movable element, e.g. a magnet

Abstract

Contactless angular offset analog sensor, of the magnetic inductance type, comprising:

a first portion forming a detector (1), comprising at least one substrate plate (3) carrying at least one flat spiral winding (4), at least one core layer (8) of material with high magnetic permeability and low saturation field over at least one portion of said winding, the detector being adapted to coact with a device for processing the electrical signal measured at the terminals of the winding,

two rotors (15, 15′) each comprising at least one magnet (18, 18′), disposed over a predetermined angular sector, the rotors being movable about a same axis (17) identical to the axis of the winding, each magnet generating in the plane of the core layer (8) a magnetic field of a value greater than the saturation field of said core layer over at least a portion of the surface of the winding.

Claims

1. Contactless analog sensor of angular offset, of the magnetic inductance type, characterized in that it comprises:

a first portion forming a detector (1), comprising at least one substrate plate (3) carrying at least one flat spiral winding (4), at least one core layer (8) of a material of high magnetic permeability and low saturation field, on at least a portion of said winding, the detector being adapted to coact with a device for processing the electric signal measured at the terminals of the winding,

two rotors (15, 15′

) each comprising at least one magnet (18, 18′

), disposed along a predetermined angular sector, the rotors being movable about a same axis (17) identical to the axis of the winding, each magnet generating in the plane of the core layer (8) a magnetic field of a value greater than the saturation field of said core layer over at least a portion of the surface of the winding.

2. Sensor according to claim 1, characterized in that the detector comprises two core layers (8A;

8B), on opposite sides of the winding (4).

3. Sensor according to claim 2, characterized in that the winding (4) comprises several parallel windings separated by insulating thicknesses.

4. Sensor according to claim 1 or 2, characterized in that the detector comprises two winding (4a;

4b) disposed on opposite sides of the substrate plate, one of the windings adapted to be connected to an alternating voltage generator and the other to a tension measuring device.

5. Sensor according to claim 1, characterized in that the detector comprises two windings (4a;

4b) disposed on opposite sides of a single core layer (8), one of the windings being adapted to be connected to an alternating voltage generator and the other to a voltage measuring device.

6. Sensor according to claim 1, characterized in that each rotor (15, 15′

) carries a series of identical magnets (18, 18′

) of a same angular sector, facing the winding (4), and separated by angular sectors of the same value.

7. Sensor according to any one of claims 1 to 2, characterized in that the detector 1 also comprises a reference winding (4′

), coaxial with the first winding (4), principally without overlapping the latter, and that only one of the rotors (15, 15′

) comprises magnets (18, 18′

) facing this reference winding (4′

).

8. Sensor according to any one of claims 1 to 5, characterized in that the magnetic permeability of the core layer is about 100,000 times that of air, and in that the saturation field is about 0.8 Tesla.

9. Sensor according to any one of claims 1 to 4, characterized in that each core layer (8A;

8B) is electrically connected to the ground of the signal processing device.

10. Sensor according to any one of the preceding claims, for the measurement of a torque, characterized in that the rotors (15;

15′

) are interconnected by a torsion bar of predetermined stiffness.