Occupant recognition system for vehicles

• US 7,181,324 B2
• Filed: 04/22/2004
• Issued: 02/20/2007
• Est. Priority Date: 04/23/2003
• Status: Expired due to Fees

• Current Assignee: Delphi Technologies, Inc. (Aptiv PLC)
• Original Assignee: Delphi Technologies, Inc. (Aptiv PLC)
• Inventors: Fischer, Thomas, Wiemer, Lars
• Primary Examiner(s): Zanelli; Michael J.
• Application Number:
  US10/829,533
• Publication Number:
  US 20040243295A1
• Time in Patent Office: 1,034 Days
• Field of Search: None
• US Class Current: 701/36
• CPC Class Codes: B60R 21/0154 in combination with seat heating

Abstract

An occupant recognition system for vehicles comprises at least one pressure sensor arranged beneath the foam of a vehicle seat, at least one temperature sensor and an electronic control and/or evaluation unit to which the sensors are connected. Means are provided to match the time behavior, in particular the time behavior present on changes in the ambient temperature, of the output signal of the temperature sensor arranged at a distance from the pressure sensor or from the seat foam to the time behavior of the temperature prevailing in the region of the pressure sensor or of the seat foam.

Claims

1. An occupant recognition system for vehicles comprising:

at least one pressure sensor disposed adjacent a foam vehicle seat;

at least one temperature sensor spaced from said seat and operative to monitor ambient air temperature within said vehicle; and

an electronic control and evaluation unit connected to said sensors and operative to match the time behavior of sensed changes in the ambient air temperature to the time behavior of the temperature prevailing in the region of the pressure sensor.

2. An occupant recognition system in accordance with claim 1, wherein a correspondingly matched output signal of the at least one temperature sensor is used for the compensation of the temperature dependence of the pressure measured via the pressure sensor.

3. An occupant recognition system in accordance with claim 1, wherein matching means are embodied within the electronic control and evaluation unit.

4. An occupant recognition system in accordance with claim 3, wherein the matching means includes a low-pass filter.

5. An occupant recognition system in accordance with claim 4, wherein the low-pass filter comprises a software filter.

6. An occupant recognition system in accordance with claim 4, wherein a Butterworth filter is provided as the low-pass filter.

7. An occupant recognition system in accordance with claim 4, wherein a Butterworth filter of the first order is provided as the low-pass filter.

8. An occupant recognition system in accordance with claim 4, wherein parameters of the filter are selected such that a filtered output signal of the temperature sensor substantially coincides with actual foam temperature.

9. An occupant recognition system in accordance with claim 1, wherein the pressure sensor includes a flexible sensor mat filled with fluid.

10. An occupant recognition system in accordance with claim 9, wherein the pressure sensor supplies a pressure value corresponding to the pressure inside the sensor mat.

11. An occupant recognition system in accordance with claim 1, wherein the pressure sensor is disposed directly beneath the seat foam.

12. An occupant recognition system in accordance with claim 1, wherein the temperature sensor includes a thermistor.

13. An occupant recognition system in accordance with claim 1, wherein the temperature sensor is disposed adjacent the electronic control and evaluation unit.

14. An occupant recognition system in accordance with claim 13, wherein the temperature sensor is disposed in a common housing with the electronic control and evaluation unit.

15. An occupant recognition system in accordance with claim 1, wherein the electronic control and evaluation unit is disposed beneath the vehicle seat.

16. An occupant recognition system in accordance with claim 1, wherein the pressure measured via the pressure sensor is compared by means of the electronic control and evaluation unit with at least one parameter value and a vehicle airbag switch status is changed in response thereto.

17. A vehicle occupant recognition system comprising:

at least one pressure sensor adapted to be disposed adjacent a vehicle foam seat cushion;

at least one temperature sensor adapted to be spaced from said foam seat cushion and operative to monitor ambient temperature within said vehicle and to generate an output signal in response thereto; and

a control unit in circuit with said sensors operative to match the time behavior of said temperature sensor output signal to the time behavior of the temperature prevailing in a region of the seat foam adjacent said pressure sensor.