Method and apparatus for determining time to fire an occupant restraint system using occupant sensor inputs

• US 6,188,940 B1
• Filed: 11/12/1998
• Issued: 02/13/2001
• Est. Priority Date: 11/12/1998
• Status: Expired due to Fees

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company), Key Safety Systems, Inc. (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Blackburn, Brian, Brown, Joseph R., Mazur, Joseph F., Gentry, Scott B.
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): MANCHO, RONNIE M
• Application Number:
  US09/190,595
• Time in Patent Office: 824 Days
• Field of Search: 701/45, 701/46, 280/735
• US Class Current: 701/45
• CPC Class Codes: B60R 2021/0102 the monitored value being used for calculating occupant displacement
• CPC Class Codes: B60R 21/0132 responsive to vehicle motion parameters , e.g. to vehicle longitudinal or transversal deceleration or speed value
• CPC Class Codes: B60R 21/0133 by integrating the amplitude of the input signal
• CPC Class Codes: B60R 21/01336 using filtering
• CPC Class Codes: B60R 21/0153 using field detection presence sensors
• CPC Class Codes: B60R 21/01546 using belt buckle sensors
• CPC Class Codes: B60R 21/01548 sensing the amount of belt winded on retractor
• CPC Class Codes: B60R 21/01554 Seat position sensors

Abstract

A method for sensing the occurrence of a vehicle crash is provided for a vehicle having an occupant restraint system operatively connected with a crash sensor having an accelerometer, which produces an accelerometer signal, and with an occupant position sensor which produces a position signal. The crash sensor includes an adjustable filter. The method includes the steps of: a) calculating an estimated occupant displacement by integrating the accelerometer signal twice; b) comparing the estimated occupant displacement to the position signal; and c) adjusting the adjustable filter based upon the comparing step to optimize control of the occupant restraint system. In this manner, actual body position of the occupant may be more accurately predicted and measured, which allows optimization of air bag deployment.

Claims

1. An apparatus for controlling an occupant restraint system including an air bag, the apparatus comprising:

a crash sensor having an accelerometer for producing a crash signal and including an adjustable filter;

an occupant position sensing system for measuring occupant position and producing a position signal; and

a controller operatively connected to said crash sensor and occupant position sensing system,

wherein the controller incorporates an algorithm for determining an appropriate time to fire the air bag based upon said crash signal and position signal, and wherein the algorithm is operative to perform the following steps;

calculating an estimated occupant displacement by integrating the crash signal twice;

comparing said estimated occupant displacement to the position signal; and

adjusting the adjustable filter based up on said comparing step to determine the appropriate time to fire the air bag.

2. The apparatus of claim 1, wherein said algorithm operation of adjusting the adjustable filter comprises using lower frequency high pass filter coefficients if the position signal leads the estimated occupant displacement.

3. The apparatus of claim 1, wherein said algorithm operation of adjusting the adjustable filter comprises using higher frequency high pass filter coefficients if the position signal lags the estimated occupant displacement.

4. A method for sensing the occurrence of a vehicle crash in a vehicle having an occupant restraint system operatively connected with a crash sensor having an accelerometer which produces an accelerometer signal, and with an occupant position sensor which produces a position signal, wherein the crash sensor includes an adjustable filter, the method comprising:

calculating an estimated occupant displacement by integrating the accelerometer signal twice;

comparing said estimated occupant displacement to the position signal; and

adjusting the adjustable filter based upon said comparing step so that said estimated occupant displacement closely correlates with the position signal, thereby optimizing control of the occupant restraint system.

5. The method of claim 4, wherein said step of adjusting the adjustable filter comprises using lower frequency high pass filter coefficients if the position signal leads the estimated occupant displacement.

6. The method of claim 4, wherein said step of adjusting the adjustable filter comprises using higher frequency high pass filter coefficients if the position signal lags the estimated occupant displacement.

7. A method for providing a passenger restraint actuation signal in a vehicle which includes a crash sensor having an accelerometer which produces an accelerometer signal, and an occupant position sensor which produces a position signal, wherein the crash sensor includes an adjustable filter, the method comprising:

calculating an estimated occupant displacement by integrating the accelerometer signal twice;

comparing said estimated occupant displacement to the position signal to determine whether a particular crash event is of long duration; and

adjusting the adjustable filter to optimize early firing time of the occupant restraint system.