Device for the classification of seat occupancy

• US 20070144273A1
• Filed: 12/15/2004
• Published: 06/28/2007
• Est. Priority Date: 12/17/2003
• Status: Abandoned Application

• Current Assignee: IEE International Electronics & Engineering SA (Aerospace Hi-Tech Holding Group Company Limited)
• Original Assignee: IEE International Electronics & Engineering SA (Aerospace Hi-Tech Holding Group Company Limited)
• Inventors: Decoster, Yves
• Application Number:
  US10/583,195
• Publication Number:
  US 20070144273A1
• Time in Patent Office: Days
• US Class Current: 73/862.391
• CPC Class Codes: B60R 21/01516 using force or pressure sensing means
• CPC Class Codes: B60R 21/01532 using electric or capacitive field sensors

Abstract

A seat occupancy sensor (12) comprises a sensing layer (14) associated to a seating surface of a seat, which has at least one electrical property varying locally in response to a pressure and/or deformation applied to said sensing layer (14). The device further comprises a plurality of electrodes (18) associated to said sensing layer (14) at a periphery of a sensing area, and a control unit (20) connected to said electrodes (18), said control unit (20) comprising means for evaluating a pressure profile acting on said sensing layer (14) by determining said at least one electrical property between pairs of electrodes (18) selected from said plurality of electrodes. The invention also relates to a method for the detection of seat occupancy comprising the steps of: c) determining said at least one electrical property of said sensing layer (14) between pairs of different locations situated at a periphery of a sensing area, and d) evaluating a pressure profile acting on said sensing layer (14) based on the determined electrical property values.

Claims

1. Device for the detection of seat occupancy, comprising

a sensing layer associated to a seating surface of a seat, said sensing layer having at least one electrical property varying in response to a pressure and/or deformation applied to said sensing layer,

a plurality of electrodes, said electrodes being associated to said sensing layer only at a periphery of a sensing area, and

a control unit connected to said electrodes, said control unit comprising means for evaluating a pressure profile acting on said sensing layer by determining said at least one electrical property between pairs of electrodes selected from said plurality of electrodes.

2. Device according to claim 1, wherein said control unit comprises means for evaluating said pressure profile using a tomography imaging method.

3. Device according to claim 1, wherein said at least one electrical property comprises the electrical impedance of said sensing layer.

4. Device according to claim 1, wherein said at least one electrical property comprises the electrical resistance or conductance of said sensing layer.

5. Device according to claim 1, wherein said sensing layer comprises a rubber material having an internal electrical impedance which varies in dependence with a deformation of the material.

6. Device according to claim 1, wherein said sensing layer comprises a foam material having an internal electrical impedance which varies in dependence with a deformation of the material.

7. Device according to claim 1, wherein said sensing layer comprises

a first carrier foil having at least one surface covered with a resistance material

a second carrier foil having at least one surface comprising a plurality of areas covered with a conductive material

said first and second carrier foil being arranged at a certain distance from each other by means of a spacer material such that said areas covered with conductive material of said second carrier foil face said coating of resistance material of said first carrier foil.

8. Device according to claim 7, wherein said resistance material is printed onto said at least one surface of said first carrier foil.

9. Device according to claim 7, wherein said conductive material is printed in said areas onto said at least one surface of said second carrier foil.

10. Device according to claim 7, wherein said spacer material comprises an adhesive, which is arranged in a plurality of localized areas between said first and second carrier foil.

11. Device according to claim 7, wherein said spacer material comprises a printable adhesive, which is printed in a plurality of localized areas onto one of said carrier foils.

12. Method for the detection of seat occupancy, said method employing a sensing layer associated to a seating surface of a seat, said sensing layer having at least one electrical property varying in response to a pressure and/or deformation applied to said sensing layer, said method comprising:

determining said at least one electrical property of said sensing layer between pairs of different locations situated only at a periphery of a sensing area, and

evaluating a pressure profile acting on said sensing layer based on the determined electrical property values.

13. Method according to claim 12, wherein said step of evaluating said pressure profile uses a tomography imaging method.