Magnetic sensing user interface device methods and apparatus

• US 10,121,617 B2
• Filed: 08/21/2011
• Issued: 11/06/2018
• Est. Priority Date: 08/20/2010
• Status: Active Grant

• Current Assignee: Seescan, Inc.
• Original Assignee: Seescan, Inc.
• Inventors: Rutledge, Austin, Merewether, Ray, Martin, Michael J., Olsson, Mark S.
• Primary Examiner(s): Yi, Roy Y
• Assistant Examiner(s): Aiello, Jeffrey
• Application Number:
  US13/214,209
• Publication Number:
  US 20120215475A1
• Time in Patent Office: 2,634 Days
• Field of Search: 7351431, 73779, 7351439, 32420721, 3242072, 32420711, 32420725, 702141, 702115, 702151, 463 37
• CPC Class Codes: G05G 9/047 the controlling member being movable by hand about orthogonal axes, e.g. joysticks for switches H01H25/04
• CPC Class Codes: G06F 3/0338 with detection of limited linear or angular displacement of an operating part of the device from a neutral position, e.g. isotonic or isometric joysticks
• CPC Class Codes: H01H 2239/024 with inductive switch
• CPC Class Codes: H01H 25/041 having a generally flat operating member depressible at different locations to operate different controls

Abstract

Methods for processing signals from a magnetic user interface device having a manual actuator are disclosed. Movements of the actuator may cause relative movement between one or more magnets and one or more corresponding sensors that may each generate signals representing independent magnetic field components detected within each sensor. A field model may be used in the magnetic user interface device to translate magnetic sensor readings during operation to position information, which may then be converted to output signals for transmission to an electronic computing system representing displacement and/or deformation of the actuator. The output signals may be generated in a predetermined format, such as USB format or other computer-interface formats, that can be interpreted by the electronic computing system.

Claims

1. A method for processing signals in a user interface device, the user interface device including an actuator element having a plurality of magnetic sensor integrated circuit elements for sensing magnetic fields in three orthogonal axes at a point in space and a corresponding plurality of magnets movable relative to the magnetic sensor elements, where the magnetic sensor elements sense magnetic fields generated by the magnets of the actuator element to determine a position or deformation of the actuator, the method comprising:

receiving, during a movement or deformation of a movable or deformable element of the actuator element from the released state, orthogonal magnetic field components associated with a position of each of the plurality of magnets resulting from the movement or deformation at the plurality of magnetic sensor elements, wherein the orthogonal magnetic field components for each of the one or more magnets is measured in three orthogonal axes of measurement;

providing output signals from the plurality of magnetic sensor elements corresponding to the received magnetic field components;

determining, based on the output signals, a radial magnetic field component associated with each of the magnets in a plane extending radially from one of the three axes of measurements;

comparing at least the radial magnetic field component to a predefined magnetic field model to determine an estimated position or deformation of the actuator element from a reference state; and

generating, based on the estimated position or deformation of the actuator element from the reference state, an output signal usable by an electronic device coupled to the user interface device;

wherein the predefined magnetic field model relates positional information of the one or more magnets with corresponding sensor information associated with the one or more magnetic sensor elements corresponding to predefined positions and/or deformations.

2. The method of claim 1, wherein the comparing the radial magnetic field component to a predefined magnetic field model includes comparing the radial magnetic field component to values in one or more lookup tables to determine the estimated position or deformation.

3. The method of claim 1, wherein the comparing the radial magnetic field component to a predefined magnetic field model includes solving, based at least on the radial magnetic field component, a closed form equation of the predefined magnetic field model to determine the estimated position or deformation.

4. The method of claim 1, wherein the one or more magnets are permanent magnets.

5. The method of claim 1, wherein the one or more magnets include an electromagnet.

6. The method of claim 1, wherein the output signal includes data defining the estimated position of the actuator element in three-dimensional space.

7. The method of claim 1, wherein the output signal includes data defining a motion of the actuator element.

8. The method of claim 1, wherein the output signal includes data defining a deformation of the actuator element.

9. The method of claim 1, wherein the predefined magnetic field model includes a lookup table relating the positional information to the radial magnetic field component.

10. The method of claim 1, wherein the predefined magnetic field model includes a mathematic model relating the position information to the radial magnetic field component.

11. The method of claim 1, wherein the reference position is a released state position.

12. The method of claim 1, wherein the reference position is offset from a released state position, the method further including:

determining the offset from the released position; and

adjusting the estimated position based on the determined offset.

13. The method of claim 12, wherein the offset is a function of temperature and the estimated position is adjusted responsive to a temperature measurement.

14. The method of claim 1, further comprising compensating for unintended displacement of the manual actuator below a predetermined minimum threshold.

15. The method of claim 12, wherein the determining the offset from the released position includes:

generating a center calibration prism including a predetermined set of boundaries of the magnetic field components detected by each sensor; and

repeatedly re-defining the center calibration prism so as to auto-zero the released state position.

16. A user interface device, comprising:

user movable actuator element including a plurality of magnets;

a plurality of three axis integrated circuit magnetic sensor elements closely paired with corresponding ones of the plurality of magnets for sensing magnetic fields, generated from the magnets, in three orthogonal axes at a compact point in space, and providing corresponding magnetic sensor output signals;

wherein the magnets are disposed on the actuator to move, in conjunction with user interaction with the actuator, relative to the magnetic sensor elements;

a non-transitory memory to store a predefined magnetic field model; and

a processing element operatively coupled to the non-transitive memory, the processing element programmed to;

receive, during a movement or deformation of the actuator element from the released state, the sensor output data from the plurality of three axis magnetic sensor elements in a three orthogonal axes of measurement;

compare the sensor data from the plurality of three axis magnetic sensor elements to the predefined magnetic field model stored in the non-transitory memory to determine an estimated position or deformation of the actuator element from a reference state; and

generate, based on the estimated position or deformation of the actuator element from the reference state, an output signal usable by an electronic device coupled to the user interface device;

wherein the predefined magnetic field model relates positional information of the plurality of magnets with corresponding sensor information associated with the plurality of three axis magnetic sensor elements.

17. The user interface device of claim 16, wherein the plurality of magnets comprise permanent magnets.

18. The user interface device of claim 16, wherein the plurality of magnets comprise cross-shaped electromagnets and the plurality of three axis magnetic sensor elements comprise high sensitivity magnetic sensor elements.

19. A user interface device, comprising:

actuator means including one or more magnets;

three axis integrated circuit magnetic sensor means associated with corresponding ones of the magnets for sensing magnetic fields generated from the associated magnets at a compact point in space;

wherein the magnets are disposed on the actuator to move, in conjunction with user interaction with the actuator, relative to the magnetic sensor elements;

wherein the actuator means is pivotably mounted to the three axis magnetic sensor means using a restorative means such that the actuator means and the associated one or more magnets are freely movable in a limited range about the three axis magnetic sensor means;

non-transitory memory means configured to store a predefined magnetic field model; and

processor means operatively coupled to the non-transitory memory means programmed to;

receive, during a movement or deformation of the actuator element from the released state, sensor data from the one or more magnetic sensor elements in a plurality of axes of measurement;

compare the sensor data from the one or more magnetic sensor elements to the predefined magnetic field model stored in the non-transitory memory means to determine an estimated position or deformation of the actuator element from the reference state; and

generate, based on the estimated position or deformation of the actuator element from the reference state, an output signal usable by an electronic device coupled to the user interface device;

wherein the predefined magnetic field model relates positional information of the one or more magnets with corresponding sensor information associated with the one or more magnetic sensor elements.

20. A method for processing signals in a user interface device, the user interface device including an actuator element having one or more magnets paired to corresponding one or more three-axis integrated circuit magnetic sensor elements, wherein the magnets are movable relative to the integrated circuit magnetic sensor elements, the method comprising:

receiving, during a movement or deformation of the actuator element from the released state, sensor data associated with three orthogonal axes of motion sensed by the multi-axis magnetic sensor elements and generated by corresponding magnets, wherein the sensor data comprises magnetic field data in three orthogonal dimensions of each of the one or more magnets, in relation to corresponding one or more multi-axis magnetic sensor elements;

comparing the sensor data from the ones of the magnetic sensor elements to a predefined magnetic field model to determine an estimated position or deformation of the actuator element from a reference state, wherein the predefined magnetic field model is a closed form solution model; and

generating, based on the estimated position or deformation of the actuator element from the reference state, an output signal usable by an electronic device coupled to the user interface device;

wherein the predefined magnetic field model relates positional information of the one or more magnets with corresponding sensor information associated with the one or more magnetic sensor elements.

21. The method of claim 20, wherein the multi-axis magnetic sensor elements comprise two axis magnetic sensors.

22. The method of claim 20, wherein the multi-axis magnetic sensor elements comprise three axis magnetic sensors.

23. The method of claim 20, wherein the one or more magnets comprise permanent magnets.

24. The method of claim 20, wherein the one or more magnets comprise a cross-shaped electromagnet and the three-axis magnetic sensor element comprises a high sensitivity magnetic sensor.

25. The method of claim 24, wherein the cross shaped electromagnet includes a first dipole element and a second dipole, the method further including selectively switching the first dipole element and the second dipole element to generate a magnetic field in three-dimensions for detection by the high sensitivity magnetic sensor.

26. A user interface device, comprising:

an actuator element having one or more magnets and corresponding one or more three axis integrated circuit magnetic sensor elements for sensing magnetic fields at a compact point in space, to sense a position or deformation of the actuator element upon movement or deformation of the actuator element;

wherein each of the one or more magnets is paired to a corresponding ones of the one or more three axis integrated circuit magnetic sensor elements;

wherein the magnets are configured to move relative to corresponding magnetic sensor elements; and

wherein each of the one or more magnets is positioned and oriented with a South pole facing towards a bottom of the actuator element and a North pole facing towards corresponding ones of the one or more magnetic sensor elements;

a non-transitory memory configured to store a predefined magnetic field model corresponding to magnetic field signals associated with movement and deformation of the actuator element in three dimensional space; and

a processing element operatively coupled to the non-transitory memory, programmed to;

receive, during a movement or deformation of the actuator element from the released state, sensor data associated with two or more orthogonal axes of motion sensed by the multi-axis magnetic sensor elements;

compare the sensor data from the ones of the magnetic sensor elements to a predefined magnetic field model stored in the memory to determine an estimated position or deformation of the actuator element from the reference state; and

generate, based on the estimated position or deformation of the actuator element from the reference state, an output signal usable by an electronic device coupled to the user interface device;

wherein the predefined magnetic field model relates positional information of the one or more magnets with corresponding sensor information associated with the one or more magnetic sensor elements.