Magnetic sensing user interface device methods and apparatus

Patent metadata

Field	Value
Publication number	US-10121617-B2
Application number	US-201113214209-A
Country	US
Kind code	B2
Filing date	Aug 21, 2011
Priority date	Aug 20, 2010
Publication date	Nov 6, 2018
Grant date	Nov 6, 2018

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.

First claim

We claim:

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

Assignees

• Rutledge Austin
• Merewether Ray
• Martin Michael J
• Olsson Mark S
• Seescan Inc

Inventors

• Rutledge Austin
• Merewether Ray
• Martin Michael J
• Olsson Mark S

Classifications

• H01H25/041 Primary

  having a generally flat operating member depressible at different locations to operate different controls · CPC title

• G05G9/047

  the controlling member being movable by hand about orthogonal axes, e.g. joysticks {(for switches H01H25/04)} · CPC title

• G06F3/0338

  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 title

• H01H2239/024

  with inductive switch · CPC title