Vehicle occupant weight estimation apparatus

• US 20030173120A1
• Filed: 03/06/2003
• Published: 09/18/2003
• Est. Priority Date: 09/19/2000
• Status: Active Grant

• Current Assignee: Intelligent Mechatronic Systems Inc. (Trak Global Group Ltd.)
• Original Assignee: Intelligent Mechatronic Systems Inc. (Trak Global Group Ltd.)
• Inventors: Johnson, Brian, Desrochers, Kristopher L., Filippov, Vladimir, Basir, Otman Adam, Karray, Fakhri
• Granted Patent: US 6,989,496 B2
• Time in Patent Office: Days
• US Class Current: 177/144
• 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 21/01554 Seat position sensors
• CPC Class Codes: G01G 19/4142 for controlling activation of safety devices, e.g. airbag systems electrical circuits for triggering safety arrangements in case of vehicle accidents B60R21/015

Abstract

This invention describes an occupant size and weight detection device consisting of a combination of force/load sensors (1), a head position sensor (2, 3), a multidirectional acceleration sensor (5), and a seat position sensor (4) used to determine the weight of an occupant based on weight distribution, body angle and foot position. The goal of the invention is to determine the weight of an occupant who is sitting in the front seat of a vehicle that is subjected to the dynamic forces resulting from the vehicle moving. This technology can be used in applications such as automotive occupant weight and position sensing for use with safety devices such as airbags.

Claims

1. A sensor for detecting the weight of an occupant in a vehicle seat comprising:

At least one load sensor coupled to a seat;

A position sensor determining the position of the occupant in the seat; and

A controller determining the weight of the occupant based upon signals from the at least one load sensor and position sensor.

2. The sensor of claim 1 wherein the at least one load sensor provides an indication of the load distribution on the vehicle seat.

3. The sensor of claim 2 wherein the at least one load sensor comprises four weight sensors.

4. The sensor of claim 1 further including at least one acceleration transducer measuring acceleration, said controller determining the weight of the occupant based upon an acceleration signal from the acceleration transducer.

5. The sensor of claim 4 wherein the at least one acceleration transducer measures acceleration in three axes.

7. The sensor of claim 1 wherein the position sensor includes a seat electrode providing a connection between the control unit and the occupant'"'"'s body to transmit an electrical field.

8. The sensor of claim 7 wherein the position sensor further includes roof-mounted electrodes connected to the controller.

9. The sensor of claim 8 wherein the controller uses a signal from each roof-mounted electrode in the array to compute the proximity of the occupant.

10. The sensor of claim 1 wherein the controller determines the body angle of the occupant and uses it to bias measurements from the at least one load sensor in order to determine the weight of the occupant.

6. The sensor of claim one further including a vehicle seatback angle sensor, said controller determining the weight of the occupant based upon a signal from the vehicle seatback angle sensor.

11. A method for determining the weight of an occupant in the vehicle seat including the steps of:

(a) measuring a load on the seating surface;

(b) determining an angle of the occupant in the seat; and

(c) determining the weight of the occupant based upon the angle and the load.

12. The method of claim 11 wherein said step (b) further includes the step of determining the position of the occupant in the seat.

13. The method of claim 11 wherein said step (a) further includes the step of measuring load distribution on the vehicle seat.

14. The method of claim 11 wherein said step (a) further includes the step of measuring load at a plurality of locations on the seat.

15. The method of claim 11 further including the steps of:

(d) measuring acceleration; and

(e) determining the weight of the occupant in step (c) based upon said step (d).

16. The method of claim 15 wherein said step (d) further includes the step of measuring acceleration in a plurality of axes.

17. A method for determining the weight of an occupant in a vehicle seat including the steps of:

(a) measuring load upon a seating surface;

(b) measuring acceleration; and

(c) determining the weight of the occupant based upon acceleration and the measured load.

18. The method of claim 17 wherein said step (b) further includes the step of measuring acceleration in a plurality of axes.