Method and system for determining weight and position of a vehicle seat occupant

• US 6,243,634 B1
• Filed: 04/13/2000
• Issued: 06/05/2001
• Est. Priority Date: 11/12/1997
• Status: Expired due to Term

• Current Assignee: Siemens Automotive Corporation (Siemens AG)
• Original Assignee: Siemens Automotive Corporation (Siemens AG)
• Inventors: Oestreicher, Ralf, Reich, Dan, Homann, Michelle, Lichtinger, Harold, Morell, Scott
• Primary Examiner(s): Rice, Kenneth R.
• Application Number:
  US09/548,485
• Time in Patent Office: 418 Days
• Field of Search: 280/735, 701/45
• US Class Current: 701/45
• 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 2/0025 by using weight measurement
• CPC Class Codes: B60N 2/0027 for detecting the position of the occupant or of occupant's body part
• CPC Class Codes: B60N 2/0031 mounted on the frame
• CPC Class Codes: B60N 2/0035 characterised by the sensor data transmission, e.g. wired connections or wireless transmitters therefor; characterised by the sensor data processing, e.g. seat sensor signal amplification or electric circuits for providing seat sensor information
• CPC Class Codes: B60N 2210/42 Strain gauges
• CPC Class Codes: B60R 21/01516 using force or pressure sensing means
• CPC Class Codes: B60R 21/0152 using strain gauges
• CPC Class Codes: H04N 1/00681 Detecting the presence, position or size of a sheet or correcting its position before scanning H04N1/047 takes precedence; mode signalling H04N1/333; skew detection or correction in image signals H04N1/3878
• CPC Class Codes: H04N 1/0071 Width
• CPC Class Codes: H04N 1/00713 Length
• CPC Class Codes: H04N 1/00779 Adjusting settings, e.g. mode, feeding rate or type of paper

Abstract

A method and system for determining weight and/or position of a vehicle seat occupant to be used for controlling the reaction of a safety restraint system. A plurality of spaced weight sensors are disposed between a seating surface and seat mounting surface to provide output signals indicative of an applied weight on each sensor. The sensors are spaced such that the sensors measure the weight applied to a seat back and the seating surface. A controller calculates the weight and/or position of the seat occupant in response to the output signals of the sensors. The controller sends the weight and position of the seat occupant to the safety restraint system to be used to tailor or suppress the reaction of the safety restraint system.

Claims

1. A weight sensing apparatus for a vehicle seat comprising:

a plurality of sensors each including a mounting portion for attachment to a vehicle seat structure and a deflectable portion that deflects in response to a weight force applied to the vehicle seat structure wherein at least one of said sensors is mounted forwardly on the seat structure to generate a front seat weight signal in response to said weight force and at least one of said sensors is mounted rearwardly on the seat structure to generate a rear seat weight signal in response to said weight force; and

a controller for comparing said front seat weight signal to said rear seat weight signal to determine occupant center of gravity and combining said front and rear seat weight signals to determine seat occupant weight.

2. An apparatus as in claim 1 including at least one strain gage mounted to said deflectable portion of each of said sensors.

3. An apparatus as in claim 2 wherein the combination of said front and rear weight signals are proportional to said weight force applied to the seat structure and wherein the apparatus includes correction factor data accessible by said processor to adjust said weight signals based on said center of gravity to generate a final weight signal representative of the actual weight of the occupant.

4. An apparatus as in claim 2 wherein said seat structure is a seat pan having a rectangular shape to define four corners and wherein said plurality of sensors is comprised of four sensors with one of said sensors mounted at each of said corners.

5. An apparatus as in claim 1 including a safety restraint device controlled by said controller in response to seat occupant weight.

6. An apparatus as in claim 5 wherein said safety restraint device is not deployed if seat occupant weight is below a predetermined weight.

7. A method for determining seat occupant weight including the steps of:

mounting at least one sensor on a forward portion of a vehicle seat structure;

mounting at least one sensor on a rearward portion of the seat structure wherein each sensor includes a deflectable portion that deflects in response to a weight force applied to the vehicle seat structure;

generating a forward weight signal in response to forward seat deflection generating a rearward weight signal in response to rearward seat deflection;

comparing the forward weight signal to the rearward weight signal to determine an occupant center of gravity and occupant position;

combining the forward and rearward weight signals to determine seat occupant weight; and

controlling a safety restraint device based on the seat occupant weight and occupant position.

8. A method as in claim 7 further comprising the step of preventing deployment of the safety restraint device if the seat occupant weight is below a predetermined weight or the occupant position is within a predetermined distance from the safety restraint device.

9. A method as in claim 8 further comprising the step of mounting a strain gage to the deflectable portion of each sensor.

10. A method as in claim 9 wherein the seat structure is a seat pan and the method further comprises the step of mounting the sensors between the seat pan and a seat track assembly.

11. A method as in claim 7 further comprising the step of generating a correction factor based on the center of gravity to adjust the measured seat occupant weight.

12. A weight sensing apparatus for a vehicle seat comprising:

a first pair of sensors mounted to a forward portion of a seat pan;

a second pair of sensors mounted to a rearward portion of said seat pan wherein each sensor includes a mounting portion for attachment to said seat pan, a support portion for attachment to a seat track member, and a deflectable portion positioned between said mounting portion and said support portion that deflects in response to a weight force applied to said seat pan such that said first pair of sensors generates a forward weight signal and said second pair of sensors generates a rearward weight signal;

a controller for comparing said front weight signal to said rear weight signal to determine occupant center of gravity and combining said front and rear seat weight signals to determine seat occupant weight; and

a safety restraint device controlled by said controller in response to seat occupant weight and center of gravity.

13. An apparatus as in claim 12 wherein the combination of said forward and rearward weight signals are proportional to said weight force applied to said seat pan and wherein the apparatus includes correction factor data accessible by said processor to adjust said weight signals based on said center of gravity to generate a final weight signal representative of the actual weight of the occupant.

14. An apparatus as in claim 13 wherein each of said sensors includes a plurality of strain gages mounted to said deflectable portion.