System and method for occupant detection and classification in motor vehicles

• US 7,516,809 B2
• Filed: 08/31/2005
• Issued: 04/14/2009
• Est. Priority Date: 08/31/2004
• Status: Expired due to Fees

• Current Assignee: Continental Automotive GmbH (Continental AG)
• Original Assignee: Siemens AG
• Inventors: Hetzenecker, Erwin, Krempl, Michael, Winkler, Gerd, Wild, Gerhard
• Primary Examiner(s): Ilan; Ruth
• Assistant Examiner(s): Brown; Drew J.
• Application Number:
  US11/216,996
• Publication Number:
  US 20060042852A1
• Time in Patent Office: 1,322 Days
• Field of Search: 180/271, 180/273, 280/735, 701/36, 374/143, 374/29, 374/44
• US Class Current: 180/273
• CPC Class Codes: B60N 2/002 Seats provided with an occupancy detection means mounted therein or thereon detection means responsive to presence or absence of children B60N2/266
• CPC Class Codes: B60R 21/01516 using force or pressure sensing means
• CPC Class Codes: B60R 21/01532 using electric or capacitive field sensors
• CPC Class Codes: B60R 21/0154 in combination with seat heating

Abstract

In an occupant detection or classification system for a motor vehicle, a sensor mat (2) measures the pressure or pressure distribution on a seating surface. A control unit (4) receives the signals from the sensor mat (2) representing an occupancy of the vehicle seat. The temperature of the foam core (1) underlying the seating surface is measured at a location other than in the center of the foam core and, specifically, at the control unit (4).

Claims

1. In combination with a vehicle seat, an occupant detection or classification system for the vehicle seat, the occupant detection or classification system comprising:

a sensor mat disposed on, in, or below a foam core of the vehicle seat;

a control unit connected to said sensor mat for receiving signals representing an occupancy of the vehicle seat and configured to output an occupant detection or classification result;

a temperature sensor disposed on or in a vicinity of said control unit and connected to said control unit, said temperature sensor outputting a measured temperature signal to said control unit representing a current temperature of the foam core of the vehicle seat; and

a material packaging said temperature sensor;

said material having a given heat transfer coefficient representing a heat transfer coefficient of the foam core, and said material having a given heat capacity representing a heat capacity of the foam core; and

said temperature sensor disposed in the foam core of the vehicle seat.

2. The occupant detection or classification system according to claim 1, further comprising a plastics enclosure packaging said temperature sensor and said control unit.

3. The occupant detection or classification system according to claim 1, further comprising a plastics enclosure packaging said temperature sensor, wherein said material is a thermoplastic material, and said plastics enclosure is an overmold formed with said thermoplastic material.

4. The occupant detection or classification system according to claim 1, wherein said temperature sensor is a plurality of thermistors disposed on said control unit.

5. The occupant detection or classification system according to claim 1, wherein said sensor mat contains a grid of a multiplicity of resistance elements respectively connected to said control unit.

6. The occupant detection or classification system according to claim 1, wherein said material forms a plastics enclosure.

7. The occupant detection or classification system according to claim 1, wherein the given heat transfer coefficient is substantially identical to a heat transfer coefficient of the foam core, and the given heat capacity is substantially identical to a heat capacity of the foam core.

8. The occupant detection or classification system according to claim 7, wherein said material forms a plastics enclosure.

9. The occupant detection or classification system according to claim 1, wherein said material has a temperature response simulating a temperature response of the foam core of the vehicle seat.

10. An occupant detection or classification system for a vehicle seat, comprising:

a sensor mat disposed on, in, or below a foam core of the vehicle seat;

a control unit connected to said sensor mat for receiving signals representing an occupancy of the vehicle seat and configured to output an occupant detection or classification result;

a temperature sensor disposed on or in a vicinity of said control unit and connected to said control unit, said temperature sensor outputting a measured temperature signal to said control unit representing a current temperature of the foam core of the vehicle seat; and

a plastics enclosure packaging said temperature sensor;

said plastics enclosure having a given heat transfer coefficient being substantially identical to a heat transfer coefficient of the foam core, and said plastics enclosure having a given heat capacity being substantially identical to a heat capacity of the foam core.

11. A motor vehicle occupant detection or classification method, which comprises:

providing a plurality of pressure sensors strategically distributed about a seating surface of a motor vehicle seat formed with a resilient core having a temperature-dependent spring behavior;

providing a temperature sensor packaged in a material having a given heat transfer coefficient being substantially identical to a heat transfer coefficient of the resilient core and having a given heat capacity being substantially identical to a heat capacity of the resilient core;

disposing the temperature sensor at a location other than a location in the resilient core directly underlying the seating surface;

measuring a pressure or a weight distribution on the seating surface with the pressure sensors and outputting at least one pressure signal;

measuring a temperature representing a temperature of the resilient core with the temperature sensor;

processing the pressure signals in dependence on a measured temperature and generating therefrom an occupant detection or classification result for further processing.

12. The occupant classification method according to claim 11, which comprises disposing the temperature sensor at or on a control unit for processing the pressure signals and wherein further processing includes adjusting an occupant safety system of the vehicle in accordance with the occupant detection or classification result.

13. An occupant detection or classification system for a vehicle seat, comprising:

a sensor mat disposed on, in, or below a foam core of the vehicle seat;

a control unit connected to said sensor mat for receiving signals representing an occupancy of the vehicle seat and configured to output an occupant detection or classification result;

a temperature sensor disposed on or in a vicinity of said control unit and connected to said control unit, said temperature sensor outputting a measured temperature signal to said control unit representing a current temperature of the foam core of the vehicle seat; and

a material packaging said temperature sensor;

said material having a given heat transfer coefficient being substantially identical to a heat transfer coefficient of the foam core, and said material having a given heat capacity being substantially identical to a heat capacity of the foam core.

14. The occupant detection or classification system according to claim 13, further comprising a plastics enclosure packaging said temperature sensor and said control unit.

15. The occupant detection or classification system according to claim 13, further comprising a plastics enclosure packaging said temperature sensor, wherein said material is a thermoplastic material, and said plastics enclosure is an overmold formed with said thermoplastic material.

16. The occupant detection or classification system according to claim 13, wherein said temperature sensor is a plurality of thermistors disposed on said control unit.

17. The occupant detection or classification system according to claim 13, wherein said sensor mat contains a grid of a multiplicity of resistance elements respectively connected to said control unit.