Determining a point of application of force on a surface element

• US 20090012725A1
• Filed: 02/23/2007
• Published: 01/08/2009
• Est. Priority Date: 02/24/2006
• Status: Active Grant

• Current Assignee: Qitec Technology Group OY
• Original Assignee: Qitec Technology Group OY
• Inventors: Vaananen, Johannes
• Granted Patent: US 7,933,738 B2
• Time in Patent Office: Days
• US Class Current: 702/41
• CPC Class Codes: G06F 3/04142 the force sensing means being located peripherally, e.g. disposed at the corners or at the side of a touch sensing plate

Abstract

The invention discloses a system for determining at least one point of application of force on a surface element. The system comprises a surface element (102, 202) having an effective mass, at least one sensor (104, 204) configured to measure force applied on the surface element (102, 202) at least one acceleration sensor (106, 206) configured to measure acceleration in at least one direction, and a processing unit (108, 210) configured to receive, from the at least one sensor (104, 204), signals indicating force applied on the surface element (102, 202), to receive, from the at least one acceleration sensor (106, 206), signals indicating acceleration, to filter out a disturbing force, determined based on acceleration signals and the effective mass of the surface element (102, 202), from the signals indicating the force applied on the surface element (102, 202), and to determine, based on the filtered signals, at least one point of application of force on the surface element (102, 202).

Claims

1. A system for determining at least one point of application of force on a surface element, wherein the system further comprises:

a surface element (102, 202) having an effective mass;

at least one sensor (104, 204) configured to measure force applied on the surface element (102, 202);

at least one acceleration sensor (106, 206) configured to measure acceleration in at least one direction;

a processing unit (108, 210) configured to receive, from the at least one sensor (104, 204), signals indicating force applied on the surface element (102, 202), to receive, from the at least one acceleration sensor (106, 206), signals indicating acceleration, to filter out a disturbing force, determined based on acceleration signals and the effective mass of the surface element (102, 202), from the signals indicating the force applied on the surface element (102, 202), and to determine, based on the filtered signals, at least one point of application of force on the surface element (102, 202).

2. The system according to claim 1, wherein the processing unit (108, 210) is configured to:

filter out the disturbing force, determined based on acceleration signals and the effective mass of the surface element (102, 202), from the signals indicating the force applied on the surface element (102, 202) in at least one direction.

3. The system according to claim 1, wherein the processing unit (108, 210) is configured to:

subtract the disturbing force from the force(s) determined based on signals from the at least one sensor (104, 204).

4. The system according to claim 3, wherein the processing unit (108, 210) is configured to:

determine, whether the result of the subtraction is less than a predetermined value; and

determine that the signals from the at least one sensor (104, 204) were not a result of application of force on the surface element (102, 202), when the result of the subtraction essentially is less than the predetermined value;

or

determine the at least one point of application of force on the surface element (102, 202) based on the corrected force values, when the result of the subtraction is greater than the predetermined value.

5. The system according to claim 1, wherein the system is arranged into a single device.

6. The system according to claim 1, wherein the system is a distributed system.

7. The system according to claim 1, wherein the surface element (102, 202) comprises solid material, liquid material or solid and liquid material.

8. A method for determining at least one point of application of force on a surface element, wherein the method comprises:

receiving, from at least one sensor (104, 204), signals indicating force applied on the surface element (102, 202);

receiving, from at least one acceleration sensor (106, 206), signals indicating acceleration in at least one direction; and

filtering out a disturbing force, determined based on acceleration signals and an effective mass of the surface element (102, 202), from the signals indicating the force applied on the surface element (102, 202); and

determining, based on the filtered signals, at least one point of application of force on the surface element (102, 202).

9. The method according to claim 8, wherein the method further comprises:

filtering out the disturbing force, determined based on acceleration signals and the effective mass of the surface element (102, 202), from the signals indicating the force applied on the surface element (102, 202) in at least one direction.

10. The method according to claim 8, wherein the method further comprises:

subtracting the disturbing force from the force determined based on signals from the at least one sensor (104, 204).

11. The method according to claim 10, wherein the method further comprises:

determining, whether the result of the subtraction is less than a predetermined value; and

determining that the signals from the at least one sensor were not a result of application of force on the surface element, when the result of the subtraction essentially is less than the predetermined value;

or

determining the at least one point of application of force on the surface element based on the corrected signal values of the at least one sensor, when the result of the subtraction is greater than the predetermined value.

12. A computer program for determining at least one point of application of force on a surface element, wherein the computer program comprises code adapted to perform the following steps when executed on a dataprocessing device:

receiving, from at least one sensor, signals indicating force applied on the surface element;

receiving, from at least one acceleration sensor, signals indicating acceleration in at least one direction; and

filtering out a disturbing force, determined based on acceleration signals and an effective mass of the surface element (102, 202), from the signals indicating the force applied on the surface element (102, 202), and

determining, based on the filtered signals, at least one point of application of force on the surface element (102, 202).

13. The computer program according to claim 12, wherein the computer program comprises code adapted to perform the following steps when executed on a data-processing device:

filtering out the disturbing force, determined based on acceleration signals and the effective mass of the surface element, from the signals indicating the force applied on the surface element.

14. The computer program according to claim 12, wherein the computer program comprises code adapted to perform the following steps when executed on a data-processing device:

subtracting the disturbing force from the force determined based on signals from the at least one sensor.

15. The computer program according to claim 14, wherein the computer program comprises code adapted to perform the following steps when executed on a data-processing device:

determining, whether the result of the subtraction is less than a predetermined value; and

determining that the signals from the at least one sensor were not a result of application of force on the surface element, when the result of the subtraction essentially is less than the predetermined value;

or

determining the at least one point of application of force on the surface element based on the corrected signal values of the at least one sensor, when the result of the subtraction is greater than the predetermined value.

16. The computer program according to claim 12, wherein the computer program is arranged in a computer-readable medium.

17. A physical object having a touch-sensitive operation interface, wherein the physical object comprises:

at least one sensor (104, 204) configured to measure force applied on a surface element (102, 202);

at least one acceleration sensor (106, 206) configured to measure acceleration of the physical object or the surface element (102, 202) in at least one direction; and

an output interface (208) configured to transmit signals from the at least one sensor (104, 204) and the at least one acceleration sensor (106, 206) to an external processing unit (210).

18. A physical object having a touch-sensitive operation interface, wherein the physical object comprises:

at least one sensor (104, 204) configured to measure force applied on a surface element (102, 202);

at least one acceleration sensor (106, 206) configured to measure acceleration of the physical object and the surface element (102, 202) in at least one direction; and

a processing unit (108, 210) configured to receive, from the at least one sensor (104, 204), signals indicating force applied on the surface element (102, 202), to receive, from the at least one acceleration sensor (106, 206), signals indicating acceleration, to filter out a disturbing force, determined based on acceleration signals and an effective mass of the surface element (102, 202), from the signals indicating the force applied on the surface element (102, 202), and to determine, based on the filtered signals, at least one point of application of force on the surface element (102, 202).

19. A processing device for determining at least one point of application of force on a surface element, wherein the processing device (108, 210) is configured to:

receive, from at least one sensor (104, 204), signals indicating force applied on the surface element (102, 202), to receive, from at least one acceleration sensor (106, 206), signals indicating acceleration, filter out a disturbing force, determined based on acceleration signals and an effective mass of the surface element (102, 202), from the signals indicating the force applied on the surface element (102, 202), and determine, based on the filtered signals, at least one point of application of force on the surface element (102, 202).