Process and circuit for controlling the control unit of a system for protecting vehicle occupants

• US 5,742,916 A
• Filed: 01/17/1997
• Issued: 04/21/1998
• Est. Priority Date: 12/23/1992
• Status: Expired due to Term

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Bischoff, Michael, Guggenberger, Johann, Leirich, Oskar
• Primary Examiner(s): Zanelli, Michael
• Application Number:
  US08/784,477
• Time in Patent Office: 459 Days
• Field of Search: 364/424.05, 364/424.055, 307/10.1, 307/10.6, 307/10.7, 180/232, 180/271, 180/282, 280/728 R, 280/734, 280/735, 340/436, 340/438
• US Class Current: 701/45
• 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 21/01336 using filtering

Abstract

A process and a circuit control a control unit of a system for protecting vehicle occupants, with a view toward triggering the protection system if the accident is sufficiently serious. The control unit contains one or more sensors which supply sensor signals during the accident, and it contains a computing unit. During the accident, the latter establishes one ACTUAL value or a plurality of different ACTUAL values characterizing the course of the accident on the basis of the sensor signals. It also automatically and continuously redefines a time-variable triggering threshold value in each case, which is namely directly or indirectly dependent on the changes in the sensor signals during the course of the accident. The computing unit compares one or more ACTUAL values with the triggering threshold value being respectively assigned to the ACTUAL value. However, on the basis of the progression of the ACTUAL value/ACTUAL values, it defines the triggering threshold value at any instant in such a way that it changes in a fluctuating manner at least during an accident phase, namely without delay in dependence on the instantaneous value of the ACTUAL value/ACTUAL values, even if during this accident phase there occur constantly major decelerations without the collision direction altering.

Claims

1. A process for controlling and adjusting a control unit of a vehicle-occupant protection system by triggering the protection system if an accident is sufficiently serious, wherein the control unit includes:

at least one sensor for supplying at least one sensor signal during the accident, and a computing unit for computing ACTUAL values characterizing a course of the accident on the basis of the sensor signal, for independently and continuously redefining a time-variable triggering threshold value, the triggering threshold value being at least indirectly dependent on the momentary sensor signal value of the sensor signal during the course of the accident, the process comprising the steps of;

a) computing with the computing unit the triggering threshold value on the basis of the progression of at least one ACTUAL value, which is determined by means of an average deceleration value,

b) increasing the triggering threshold value with an increasing amount of the average deceleration;

c) comparing with the computing unit the triggering threshold value with another ACTUAL value; and

d) triggering the protection system if the other ACTUAL value exceeds the triggering threshold value.

2. The process according to claim 1, which comprises establishing a plurality of different ACTUAL values with the computing unit.

3. The process according to claim 1, which comprises establishing at least one ACTUAL value corresponding to a deceleration and an ACTUAL value of a travel/time corresponding to a loss in speed, with the computing unit.

4. The process according to claim 1, which comprises:

supplying a deceleration signal from the at least one sensor in the form of a crash sensor in the event of an accident;

performing at least one time integration of the deceleration signal from a starting time with the computing unit during the accident, for determining the at least one ACTUAL value; and

comparing the ACTUAL value determined through the integration with a time-variable triggering threshold value in the computing unit.

5. The process according to claim 4, which comprises performing the time integration of the deceleration signal for determining an ACTUAL loss in speed.

6. The process according to claim 4, which comprises performing a time integration of the deceleration signal with the computing unit over a short time duration in comparison with the duration of the deceleration signal, for continually determining a current partial loss in speed, as the current speed value, during the accident.

7. The process according to claim 6, which comprises performing the time integration of the deceleration signal for only 5 msec, and beginning the time duration in advanced accident phases after the starting time.

8. The process according to claim 4, which comprises performing a time integration of the deceleration signal over the entire duration thus far as the integration with the computing unit, commencing from the starting time, for continually determining a total current loss in speed occurring since the starting time by approximation during the accident.

9. The process according to claim 8, which comprises performing the time integration of the deceleration signal with the computing unit exclusively.

10. The process according to claim 8, which comprises performing the time integration of the deceleration signal with the computing unit additionally.

11. The process according to claim 8, which comprises making the current triggering threshold value dependent on at least one stored past value having been determined by the computing unit during previous phases of the accident, and mathematically defining and making the triggering threshold value dependent on at least a first component depending on the amount of a current deceleration average value, and a second component depending on stored amounts of past values.

12. The process according to claim 11, which comprises respectively representing the first and second component by an element of a mathematical difference, in which the first component forms a subtrahend and contains a weighted amount of the current deceleration average value, and the second component forms a minuend and contains a weighted difference between the amounts of the respective past values.

13. The process according to claim 12, which comprises multiplying the first component by a first weighting factor, and multiplying the second component by a second weighting factor.

14. The process according to claim 1, which comprises also making the current triggering threshold value dependent on at least one stored past value amount having been determined by the computing unit during previous phases of the accident.

15. The process according to claim 14, which comprises using previously determined triggering threshold values as current values for those times for which at least one of the last minimum and the maximum preceding the last minimum of the progression of the respectively determined at least partial loss in speed.

16. The process according to claim 15, which comprises using a difference between a sum of the determined partial loss in speed during the last minimum and during the maximum preceding the last minimum as the past value, wherein the triggering threshold value becomes respectively one of a greater and smaller threshold value according to a rising and a falling difference.

17. The process according to claim 16, which comprises dividing the difference by an amount of the determined loss in speed for the respective maximum.

18. The process according to claim 17, which comprises dividing the difference by the amount of the determined loss in speed for the respective minimum.

19. The process according to claim 16, which comprises dividing the difference by the amount of a time period between the respective minimum and respective maximum.

20. The process according to claim 1, which comprises setting the triggering threshold value to a constant value at predetermined times.

21. The process according to claim 1, which comprises defining the triggering threshold value with the computing unit by a division of a currently determined, at least partial loss in speed through a time duration and consequently by determination of a current deceleration average value.

22. A method for controlling and adjusting a protection system for occupants of a vehicle if a crash is sufficiently serious, the vehicle including:

at least one sensor supplying sensor signals during an accident; and

a computing unit establishing at least one ACTUAL value characterizing a progression of the accident on the basis of the sensor signals, during the accident, for automatically and continuously redefining a time-variable triggering threshold value, the threshold value being at least indirectly dependent on changes in the sensor signals during the course of the accident, the method which comprises the steps of;

a) determining differences between the ACTUAL value and the triggering threshold value assigned to the ACTUAL value;

b) defining the triggering threshold value on the basis of the progression of the ACTUAL value, and

c) increasing the triggering threshold value with an amount equal to an actual increase in the average deceleration in a fluctuating manner during an accident phase, in dependence on an instantaneous value of the ACTUAL value, if decelerations occur during the accident phase, and

d) triggering the protection system if the deceleration exceeds the threshold value.

23. The method according to claim 22, including establishing with said computing unit a plurality of different ACTUAL values.

24. The method according to claim 22, including establishing with said computing unit at least one of an ACTUAL value corresponding to a deceleration and an ACTUAL value of a travel/time corresponding to a loss in speed.

25. The method according to claim 22, including providing in the protective system an air bag system.