Method of determining the object on a seat for determining the deployment mode of a safety device

• US 6,366,200 B1
• Filed: 09/06/2000
• Issued: 04/02/2002
• Est. Priority Date: 09/07/1999
• Status: Expired due to Term

• Current Assignee: Joyson Safety Systems Japan K.K.
• Original Assignee: Takata Corporation (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Aoki, Hiroshi
• Primary Examiner(s): Lefkowitz, Edward
• Application Number:
  US09/656,222
• Time in Patent Office: 573 Days
• Field of Search: 340/438, 340/439, 340/666, 340/667, 340/436, 280/734, 280/735, 180/272, 180/273, 177/138, 177/144, 177/210.C
• US Class Current: 340/438
• 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 21/01556 Child-seat detection systems
• 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

To provide a method of determining the presence and the kind of the object on the seat of the passenger vehicle accurately. When the seat weight w is below w₁, it is determined that the seat vacant. When the seat weight is equal to or above w₁, determination is made whether or not the output p of the living body proximity sensor is below the threshold value p₁. In the case where the output p of the living body proximity sensor is below the threshold value p₁, it is determined that a child is sitting on the seat when the seat weight is below w₂, and that an adult is sitting on the seat when the seat weight is equal to or above w₂. When the output of the living body proximity sensor is equal to or above threshold value p₁, it is determined that a child seat is mounted on the seat.

Claims

1. A method of determining the deployment mode of an airbag, comprising the steps of:

determining the seat weight using a seat weight sensor;

determining the contents of the seat using a living body proximity sensor having an electrostatic capacitance by detecting a change in the electrostatic capacitance of the sensor resulting from a living body located in the proximity of the sensor; and

determining the deployment mode of the airbag based on the determinations made using the seat weight and living body proximity sensors.

4. The method of claim 1, further comprising the steps of:

determining that a child is present on the seat when the output value of the living body proximity sensor shows that the living body is in the proximity thereof and the seat weight is equal to or above the prescribed value w₁ and below a prescribed value w₂ (w₁<

w₂<

w₃).

5. The method of claim 1, further comprising the steps of:

determining that an adult is present on the seat when the output value of the living body proximity sensor shows that the living body is in the proximity thereof and the seat weight is above a prescribed value w₂ (w₁<

w₂<

w₃).

2. A method of determining the deployment mode of an airbag, comprising the steps of:

determining the seat weight using a seat weight sensor;

determining the contents of the seat using a living body proximity sensor including a coil having an induced voltage by detecting a change in the induced voltage resulting from a living body located in the proximity of the sensor; and

determining the deployment mode of the airbag based on the determinations made using the seat weight and living body proximity sensors.

3. A method of determining the presence and the type of object on the seat of the passenger vehicle, comprising the steps of:

determining whether the seat is vacant; and

if the seat is not vacant, determining whether the object present on the seat is a child seat, a child, or an adult by the combination of outputs from a seat weight sensor and a living body proximity sensor;

determining that the seat is vacant when the seat weight is below a prescribed value w₁; and

determining that the living body proximity sensor is out of order when the output value of the living body proximity sensor does not show that the living body is in the proximity thereof and the seat weight is equal to or above a prescribed value w₃ that is greater than the prescribed value w₁.

6. A method of determining the presence and the type of object on the seat of the passenger vehicle, comprising the steps of:

determining whether the seat is vacant; and

if the seat is not vacant, determining whether the object present on the seat is a child seat, a child, or an adult by the combination of outputs from a seat weight sensor and a living body proximity sensor;

determining that the seat is vacant when the seat weight is below a prescribed value w₁; and

determining a threshold output value of the living body proximity sensor, wherein the threshold output value is a function f(w) of the output of the seat weight sensor;

determining that a child is present on the seat when the seat weight is equal to or above the prescribed value w₁ and below a prescribed value w₂ (w₁<

w₂) and when the output value of the living body proximity sensor is smaller than the threshold output value for the seat weight as determined by the function f(w).

7. The method of claim 6, further comprising the step of determining that an adult is present on the seat when the seat weight is equal to or above the prescribed value w₁ and above the prescribed value w₂ and when the output value of the living body proximity sensor is smaller than the threshold output value for the seat weight as determined by the function f(w).

8. The method of claim 6, further comprising the step of determining that a child seat is present on the seat when the seat weight is equal to or above the prescribed value w₁ and less than a prescribed value w₃ (w₁<

w₃) and when the output value of the living body proximity sensor is equal to or above the threshold output value for the seat weight as determined by the function f(w).

9. The method of claim 6, further comprising the step of determining that an adult is present on the seat when the seat weight is above a prescribed value w₃ (w₁<

w₃) and when the output value of the living body proximity sensor is equal to or above the threshold output value for the seat weight as determined by the function f(w).

10. A method of determining an airbag deployment mode using the combination of an output from a seat weight sensor and an output from a living body proximity sensor, comprising the steps of:

determining a threshold output value of a living body proximity sensor mounted on the seat, wherein the threshold output value is a function f(w) of the output of a seat weight sensor;

determining that a low deployment mode is selected when the seat weight is equal to or above a prescribed value w₁ and below a prescribed value w₂ (w₁<

w₂) and when the output of the living body proximity sensor is smaller than the threshold output for the seat weight as determined by the function f(w).

11. The method of claim 10, further comprising the step of:

determining a normal deployment mode is selected when the seat weight is equal to or above w₂, and when the output of the living body proximity sensor is smaller than the threshold output for the seat weight as determined by the function f(w).

12. The method of claim 10, further comprising the step of:

determining that a low deployment mode is selected when the output from the living body proximity sensor is equal to or above the threshold output for the seat weight as determined by the function f(w), and the seat weight is smaller than a prescribed value w₃ (w_l<

w₃).

13. The method of claim 12, further comprising the step of:

determining that a normal deployment mode is selected when the output from the living body proximity sensor is equal to or above the threshold output for the seat weight as determined by the function f(w), and the seat weight is equal to or above w₃.

14. A method of determining an airbag deployment mode using the combination of an output from a seat weight sensor and an output from a living body proximity sensor, comprising the steps of:

determining a threshold output value of a living body proximity sensor mounted on the seat, wherein the threshold output value is a function f(w) of the output of a seat weight sensor;

determining that a no deployment mode is selected when the seat weight is equal to or above a prescribed value w₁and below a prescribed value w₂ (w₁<

w₂) and when the output of the living body proximity sensor is smaller than the threshold output for the seat weight as determined by the function f(w).

15. The method of claim 14, further comprising the step of:

determining a normal deployment mode is selected when the seat weight is equal to or above w₂, and when the output of the living body proximity sensor is smaller than the threshold output for the seat weight as determined by the function f(w).

16. The method of claim 14, further comprising the step of:

determining that a no deployment mode is selected when the output from the living body proximity sensor is equal to or above the threshold output for the seat weight as determined by the function f(w), and the seat weight is smaller than a prescribed value w₃ (w₁<

w₃).

17. The method of claim 16, further comprising the step of:

determining that a normal deployment mode is selected when the output from the living body proximity sensor is equal to or above the threshold output for the seat weight as determined by the function f(w), and the seat weight is equal to or above w₃.