Restraint deployment control method with speed-dependent adjustment of deployment threshold

• US 6,236,308 B1
• Filed: 05/10/1999
• Issued: 05/22/2001
• Est. Priority Date: 11/09/1998
• Status: Expired due to Term

• Current Assignee: Aptiv Technologies Limited (BorgWarner Incorporated)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Dalum, Joseph Thomas
• Primary Examiner(s): TONG, NINA C
• Application Number:
  US09/307,856
• Time in Patent Office: 743 Days
• Field of Search: 340/436, 340/435, 340/901, 340/903, 340/904, 307/10.1, 701/45, 280/735, 180/282, 180/273
• US Class Current: 340/436
• CPC Class Codes: B60R 2021/01006 Mounting of electrical components in vehicles
• CPC Class Codes: B60R 21/0132 responsive to vehicle motion parameters , e.g. to vehicle longitudinal or transversal deceleration or speed value

Abstract

An improved deployment method for a vehicular supplemental restraint system having an acceleration sensor and a restraint device to be deployed for occupant protection in a crash event, where the deployment is initiated when a filtered version of the acceleration signal exceeds a deployment threshold that is periodically adjusted based on one or more secondary measures of crash severity, including a vehicle speed measurement at the onset of the crash event, and the level of event progression. In a first embodiment, the vehicle speed measurement pertains to the ground or absolute speed of the vehicle at the onset of the crash event; in a second embodiment, the vehicle speed measure pertains to the vehicle speed relative to a detected obstacle at the onset of the crash event.

Claims

1. In a vehicular supplemental restraint system having a sensor providing a vehicle acceleration signal, a restraint device and a controller for deploying the restraint device for vehicle occupant protection in a crash event when a measure of crash severity based on the acceleration signal exceeds a deployment threshold, the improvement wherein the controller:

initializes the deployment threshold at a default level prior to the crash event;

determines an event progression signal during the crash event based on the acceleration signal, and an event progression level based on the magnitude of the event progression signal relative to one or more predefined event progression thresholds;

determines a measure of vehicle velocity at the onset of the crash event; and

periodically adjusts the deployment threshold during the crash event based on the measure of vehicle velocity and event progression level.

2. The improvement of claim 1, wherein the measure of vehicle velocity is the vehicle velocity a predetermined period of time prior to:

the acceleration signal exceeding a predetermined threshold, or the achievement of a specified event progression level.

3. The improvement of claim 1, wherein the measure of vehicle velocity includes a measure of the velocity of the vehicle relative to an obstacle in a travel path of the vehicle.

4. The improvement of claim 1, wherein the controller forms velocity thresholds as a function of the determined event progression level, and the deployment threshold is periodically adjusted during the course of the crash event by adjustment amounts selected based on a comparison of the vehicle velocity measure with said velocity thresholds.

5. The improvement of claim 4, wherein said adjustment amounts are summed in the course of the crash event, and the controller limits the summation of said adjustment amounts to a predefined limit value, thereby limiting the adjustment of said deployment threshold due to said vehicle velocity measure.

6. A control method for a vehicular supplemental restraint system having a sensor providing a vehicle acceleration signal, a restraint device that can be deployed in a crash event for vehicle occupant protection, the method comprising the steps of:

initializing a deployment threshold at a default level prior to the crash event;

determining an event progression signal during the crash event based on the acceleration signal;

determining an event progression level based on the magnitude of the event progression signal relative to one or more predefined event progression thresholds;

determining a measure of vehicle velocity at the onset of the crash event;

periodically adjusting the deployment threshold during the crash event based on the measure of vehicle velocity and event progression level; and

deploying the restraint device when a measure of crash severity based on the acceleration signal exceeds the deployment threshold.

7. The control method of claim 6, wherein the measure of vehicle velocity is determined as the vehicle velocity a predetermined period of time prior to:

the acceleration signal exceeding a predetermined threshold, or the achievement of a specified event progression level.

8. The control method of claim 6, wherein the step of determining a measure of vehicle velocity includes measuring of the velocity of the vehicle relative to an obstacle in a travel path of the vehicle.

9. The control method of claim 6, including the steps of:

selecting velocity thresholds as a function of the determined event progression level; and

periodically adjusting the deployment threshold during the course of the crash event by adjustment amounts selected based on a comparison of the vehicle velocity measure with the selected velocity thresholds.

10. The control method claim 9, including the steps of:

summing the adjustment amounts in the course of the crash event; and

limiting the summation of said adjustment amounts to a predefined limit value, thereby limiting the adjustment of said deployment threshold due to said vehicle velocity measure.