Determining a point of application of force on a surface element

• US 7,933,738 B2
• Filed: 02/23/2007
• Issued: 04/26/2011
• Est. Priority Date: 02/24/2006
• Status: Expired due to Fees

• Current Assignee: Qitec Technology Group OY
• Original Assignee: Qitec Technology Group OY
• Inventors: Väänänen, Johannes
• Primary Examiner(s): Dunn; Drew A
• Assistant Examiner(s): VO, HIEN XUAN
• Application Number:
  US11/710,156
• Publication Number:
  US 20090012725A1
• Time in Patent Office: 1,523 Days
• Field of Search: 702/139, 702/41, 702/98, 702/95, 702/190, 345/173, 345/156, 178/18.02
• US Class Current: 702/139
• 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

A system for determining at least one point of application of force on a surface element is provided. The system includes a surface element having an effective mass, at least one sensor configured to measure force applied on the surface element at least one acceleration sensor configured to measure acceleration in at least one direction, and a processing unit configured to receive, from the at least one sensor, signals indicating force applied on the surface element, to receive, from the at least one acceleration sensor, signals indicating acceleration, to filter out a 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, and to determine, based on the filtered signals, at least one point of application of force on the surface element.

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 having a mass;

a supporting structure;

sensors configured to measure force applied on the surface element, the sensors being arranged between the surface element and the supporting structure;

at least one acceleration sensor configured to measure acceleration in at least one direction;

a processing unit configured to receive, from the sensors, signals indicating force applied on the surface element, to receive, from the at least one acceleration sensor, signals indicating acceleration, to filter out a disturbing force in at least one direction, calculated from acceleration signals and the mass of the surface element from the signals indicating the force applied on the surface element, and to calculate from the filtered signals, at least one point of application of force on the surface element by subtracting the disturbing force from the force(s) determined based on signals from the sensors; and

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

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

or

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

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

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

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

receiving, from sensors, signals indicating force applied on the surface element, the sensors being arranged between the surface element and a supporting structure;

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

filtering out a disturbing force in at least one direction from, determined acceleration signals and a mass of the surface element, from the signals indicating the force applied on the surface element and

determining, from the filtered signals, at least one point of application of force on the surface element by subtracting the disturbing force from the force(s) determined based on signals from the sensors; and

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

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

or

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

5. A computer program embodied on a non-transitory computer readable medium 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 data-processing device:

receiving, from at least one sensor, signals indicating force applied on the surface element, the sensors being arranged between the surface element and a supporting structure;

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

filtering out a disturbing force in at least one direction, determined based on acceleration signals and a mass of the surface element, from the signals indicating the force applied on the surface element, and

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

6. The computer program according to claim 5, 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.

7. The computer program according to claim 6, 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 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.