System and method for occupant detection and classification in motor vehicles

• US 20060042852A1
• Filed: 08/31/2005
• Published: 03/02/2006
• Est. Priority Date: 08/31/2004
• Status: Active Grant

• Current Assignee: Continental Automotive GmbH (Continental AG)
• Original Assignee: Siemens AG
• Inventors: Winkler, Gerd, Hetzenecker, Erwin, Wild, Gerhard, Krempl, Michael
• Granted Patent: US 7,516,809 B2
• Time in Patent Office: Days
• US Class Current: 180/271
• 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: B60N 2/0024 for identifying, categorising or investigation of the occupant or object on the seat
• CPC Class Codes: B60N 2210/30 Temperature sensors
• CPC Class Codes: B60N 2210/40 Force or pressure sensors
• 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. An occupant detection or classification system for a vehicle seat, comprising:

a sensor mat (2) disposed on, in, or below a foam core (1) of the vehicle seat;

a control unit (4) connected to said sensor mat (2) for receiving signals representing an occupancy of the vehicle seat and configured to output a occupant detection or classification result;

a temperature sensor (5) disposed on or in a vicinity of said control unit (4) and connected to said control unit (4), said temperature sensor (5) outputting a measured temperature signal to said control unit (4) representing a current temperature of the foam core (1) of the vehicle seat.

2. The occupant detection or classification system according to claim 1, wherein said temperature sensor (5) is packaged in a plastics enclosure (6) having a given heat transfer coefficient and a given heat capacity.

3. The occupant detection or classification system according to claim 2, wherein the given heat transfer coefficient and the given heat capacity of said plastics enclosure (6) is substantially identical to a heat transfer coefficient and the heat capacity of the foam core (1).

4. The occupant detection or classification system according to claim 1, wherein said temperature sensor (5) and said control unit (4) are commonly packaged in a plastics enclosure (6).

5. The occupant detection or classification system according to claim 1, wherein said plastics enclosure (6) is an overmold formed with a thermoplastic material.

6. The occupant detection or classification system according to claim 1, wherein said temperature sensor (5) is a plurality of thermistors disposed on said control unit (4).

7. The occupant detection or classification system according to claim 1, wherein said sensor mat (2) contains a grid of a multiplicity of resistance elements respectively connected to said control unit.

8. 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;

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 of the resilient core at a location other than a location in said resilient core directly underlying the seating surface;

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

9. The occupant classification method according to claim 8, which comprises measuring the temperature with a temperature sensor disposed 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.