Method and device for forming a deployment criterion for a restraint system

• US 6,353,783 B1
• Filed: 08/30/2000
• Issued: 03/05/2002
• Est. Priority Date: 11/29/1997
• Status: Expired due to Term

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Groesch, Lothar, Baumann, Torsten, Hafner, Sigrid, Henne, Michael
• Primary Examiner(s): Chin, Gary
• Application Number:
  US09/555,200
• Time in Patent Office: 552 Days
• Field of Search: 701/45, 701/46, 701/47, 280/734, 280/735, 180/274, 180/282, 307/10.1, 340/436, 340/438, 738/620.41
• US Class Current: 701/45
• CPC Class Codes: B60R 2021/01322 comprising variable thresholds, e.g. depending from other collision parameters
• CPC Class Codes: B60R 21/0132 responsive to vehicle motion parameters , e.g. to vehicle longitudinal or transversal deceleration or speed value

Abstract

A method and/or a device for forming a robust and reliable deployment criterion for a restraint system in a motor vehicle is formed with the help of a fuzzy classifier which receives at least two input quantities. The first input quantity is an operating time which begins when the measured acceleration exceeds a predetermined threshold; and a second input quantity takes into account the change in vehicle speed determined from the measured acceleration.

Claims

1. A method of forming a deployment criterion for a restraint system in a motor vehicle, comprising:

measuring an acceleration of the vehicle; and

deriving the deployment criterion as a function of the measured acceleration using a fuzzy method for deciding whether the restraint system should be deployed, the deriving step including forming the deployment criterion using a fuzzy classifier, the fuzzy classifier receiving at least two input quantities, a first one of the input quantities representing an operating time which begins when the measured acceleration exceeds a predetermined threshold, and a second one of the input quantities representing a change in vehicle speed based on the measured acceleration.

2. The method according to claim 1, wherein the second one of the input quantities is formed from sampled acceleration values according to the following equation:

$\mathrm{E2}=\frac{\underset{j=0}{\overset{i}{\sum <br><br>}}<br><br>a<br><br>\left(j\right)<br><br>\mathrm{\Delta <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>t}{i},$

wherein E2 is the second one of the input quantities, a(j) is a j-th sampled acceleration value, Δ

t is a sampling time and i is the operating time.

3. The method according to claim 1, wherein the fuzzy classifier receives a third input quantity representing an average of the measured accelerations.

4. The method according to claim 3, wherein the third input quantity is formed according to the following equation:

$\mathrm{E3}=\frac{\frac{a<br><br>\left(i\right)+a<br><br>\left(i-1\right)}{2}-\frac{a<br><br>\left(i-1\right)+a<br><br>\left(i-2\right)}{2}}{\mathrm{\Delta <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>t},$

wherein E3 is the third input quantity, a(i), a(i−

1) and a(i−

2) are sampled acceleration values and Δ

t is a sampling time.

5. A device for forming a deployment criterion for a restraint system in a motor vehicle, comprising:

a sensor that measures acceleration of the motor vehicle; and

a fuzzy classifier that forms the deployment criterion, the fuzzy classifier receiving at least two input quantities, a first one of the input quantities representing an operating time which begins when the measured acceleration exceeds a predetermined threshold, and a second input quantity representing a change in vehicle speed determined as a function of the measured acceleration.