Multi-dimensional measurement using magnetic sensors and related systems, methods, and integrated circuits

• US 10,697,800 B2
• Filed: 08/22/2017
• Issued: 06/30/2020
• Est. Priority Date: 11/04/2016
• Status: Active Grant

• Current Assignee: Analog Devices International Unlimited Company (Analog Devices, Inc.)
• Original Assignee: Analog Devices, Inc.
• Inventors: Schmitt, Jochen
• Primary Examiner(s): Assouad, Patrick
• Assistant Examiner(s): Curtis, Sean
• Application Number:
  US15/682,966
• Publication Number:
  US 20180128648A1
• Time in Patent Office: 1,043 Days
• Field of Search: 32420713, 32420721, 324252
• CPC Class Codes: G01D 5/145 influenced by the relative movement between the Hall device and magnetic fields see G01R33/06
• CPC Class Codes: G01D 5/1655 more than one point of contact or actuation on one or more tracks
• CPC Class Codes: G01R 33/096 anisotropic magnetoresistance sensors

Abstract

This disclosure describes, among other things, embodiments of devices, systems, and methods for using 3-dimensional (3D) magnetic sensors to detect the position of a magnetic target. By using 3D magnetic sensors, a two dimensional array of such magnetic sensors can be used to determine a 3D position of a magnetic target.

Claims

1. A system for detecting a position of a magnetic target, the system comprising:

an array of magnetic sensor integrated circuits (ICs), wherein a first magnetic sensor IC of the array comprises at least three first magnetic sensing elements and one or more first output contacts configured to provide first information indicative of a 3-dimensional (3D) position of the magnetic target, wherein the at least three first magnetic sensing elements comprise two magnetic sensing elements positioned on a first substrate plane and another magnetic sensing element positioned on a second substrate plane, the second substrate plane oriented at a non-zero angle relative to the first substrate plane, and wherein a second magnetic sensor IC of the array comprises at least three second magnetic sensing elements and one or more second output contacts configured to provide second information indicative of the 3D position of the magnetic target; and

a computation circuit configured to output 3D position information of the magnetic target positioned in proximity to the array based on the first information and the second information.

2. The system of claim 1, wherein the at least three first magnetic sensing elements are anisotropic magnetoresistive sensing elements.

3. The system of claim 1, wherein the at least three first magnetic sensing elements comprise an additional magnetic sensing element positioned on the second substrate plane.

4. The system of claim 1, wherein the computation circuit is configured to determine a coarse position to determine a group of magnetic sensor ICs of the array to use for a fine position measurement, wherein the group comprises the first magnetic sensor IC and the second magnetic sensor IC, and wherein the 3D position information comprises the fine position measurement.

5. The system of claim 4, wherein the computation circuit is configured to determine three-dimensional rotation information for the magnetic target.

6. The system of claim 1, wherein the computation circuit is configured to output three-dimensional rotation information of the magnetic target.

7. The system of claim 1, wherein a column of magnetic sensor ICs of the array includes magnetic sensors ICs that are unevenly spaced from adjacent magnetic sensor ICs in the column.

8. The system of claim 1, wherein a maximum distance between two IC adjacent magnetic sensor ICs of the array that are closest to each other is less than a largest dimension of the magnetic target.

9. The system of claim 1, wherein the computation circuit comprises a microcontroller.

10. The system of claim 9, wherein the computation circuit further comprises an analog-to-digital converter coupled between the magnetic sensor ICs of the array and the microcontroller.

11. A method of determining a position of a magnetic target, the method comprising:

determining a coarse position of the magnetic target to identify a group of magnetic sensors of an array of magnetic sensors that generate a respective signal that satisfies a threshold;

measuring a rotation of the magnetic target based on measurements of magnetic sensors of the group of magnetic sensors, wherein magnetic sensors of the array each comprise two magnetic sensing elements on a first substrate and a third magnetic sensing element on a second substrate that is oriented at a non-zero angle relative to the first substrate, the second substrate being different than the first substrate; and

determining a fine position of the magnetic target based on measurements of magnetic sensors of the group of magnetic sensors.

12. The method of claim 11, further comprising:

measuring an updated fine position of the magnetic target;

determining an updated coarse position of the magnetic target; and

determining an updated rotation of the magnetic target based on the updated fine position.

13. The method of claim 11, further comprising:

measuring an updated rotation of the magnetic target;

determining an updated fine position of the magnetic target; and

determining an updated coarse position of the magnetic target based on the updated rotation of the magnetic target.

14. The method of claim 11, wherein the fine position is a three-dimensional position, and wherein the measuring the rotation comprises measuring rotation of the magnetic target in three-dimensions.

20. The method of claim 11, wherein each of the two magnetic sensing elements and the third magnetic sensing element is a full bridge anisotropic magnetoresistive (AMR) sensing element.

15. An magnetic sensor for detecting a position of a magnetic target, the magnetic sensor comprising:

a first magnetic sensing element and a second magnetic sensing element positioned on a first substrate plane;

a third magnetic sensing element and a fourth magnetic sensing element positioned on a second substrate plane oriented at a non-zero angle relative to the first substrate plane, wherein a single integrated circuit includes the first, second, third, and fourth magnetic sensing elements; and

one or more output contacts of the single integrated circuit configured to provide information from the first, second, third, and fourth magnetic sensing elements indicative of a 3-dimensional (3D) position of the magnetic target.

16. The magnetic sensor of claim 15, further comprising a processing circuit configured to receive data from the first, second, third, and fourth magnetic sensing elements and to calculate an angle of a magnetic field based on the received data.

17. The magnetic sensor of claim 15, wherein the first magnetic sensing element comprises an anisotropic magnetoresistive (AMR) sensing element.

18. The magnetic sensor of claim 15, wherein the first magnetic sensing element comprises magnetoresistive elements arranged in a full bridge configuration.

19. The magnetic sensor of claim 15, wherein the first substrate plane is substantially orthogonal to the second substrate plane.