DE102004008600A1 - Passenger protection system releasing method for motor vehicle, involves determining nature of accident based on time difference of collision signals obtained from vehicle sensors to adjust release time of e.g. airbag - Google Patents

Abstract

The invention relates to a method for triggering an occupant protection system for a vehicle (10), comprising at least two sensors (21, 21 ', 22, 22', 23) for triggering at least one protection means (11) in the event of an accident of the vehicle. A chronological sequence of collision signals (V1, V2, V3, V4) of the sensors (21, 21 ', 22, 22', 23) is detected and used to determine an accident type, wherein the determined type of accident is used to adapt the tripping behavior of the occupant protection system becomes.

Description

The The invention relates to a method for triggering an occupant protection system for a A motor vehicle according to claim 1 and an occupant protection system for a vehicle according to claim 15.

to Improving road safety will be occupant protection systems, the one control unit with one or more sensors and associated restraint means, continuous improved, so that in an accident optimal protection for the occupants guaranteed is. An improvement of the protective effect is in particular by Influencing the triggering thresholds and the triggering times of the occupant protection system.

It are already numerous occupant protection systems in use, the one control unit with centrally located sensor and supplemented by additional sensors, Have the so-called assistance sensors. The assistant sensors, Satellite sensors or outsourced sensors are usually here near attached to the body of the vehicle. They will be more specific Task arranged in the vehicle. For quick detection of a frontal impact For example, assistance sensors are mounted near the front of the vehicle, which be referred to as upfront sensors. For quick recognition of a Side impact, for example, assistance sensors near the vehicle side attached, such as in the door area; these sensors will be Called side sensors.

Especially in a side impact is the time available, measured from the contact of the collision partners to the triggering of restraints particularly short. This is due to the small crumple zone in the area of the vehicle side. Therefore In the case of a side impact, it is necessary to take the triggering decision for the Protective means of occupant protection system as early as possible to make and Protective agent as possible to drive quickly. In such a situation is usually a final assessment the acceleration signal at a time required at the accidental acceleration has not yet reached its maximum value Has. To an early and yet reliable Decision over the type of accident, ie in particular the impact speed and direction, Therefore, the outsourced sensors are provided. The control unit evaluates the acquired acceleration values of the outsourced sensors and the acceleration values of your own centrally located sensors to make a trigger decision to meet.

From the DE 44 25 846 A1 A method for triggering side airbags of a safety device for motor vehicles is known in which the information of a centrally located in the vehicle acceleration sensor is linked to the information from side satellites to derive therefrom a trigger signal. Each of the sensor signals is checked to see if it exceeds predetermined thresholds; in accordance with the exceeded threshold values, the signal is classified into an acceleration class. The class assignment of the sensor signals is evaluated by means of an evaluation matrix and, depending on the result of the evaluation, optionally a trigger signal is generated. The triggering matrix determines which combination of the detected accelerations leads to a trigger signal and in which combinations no triggering of the restraint means takes place.

From the DE 101 14 277 C1 a device for detecting a side impact in a motor vehicle is known in which a triggering decision based on the signatures of the acceleration sensors for controlling the protection means is generated with a central acceleration sensor and outsourced acceleration sensors. Here, the outsourced acceleration sensors are mounted asymmetrically with respect to the vehicle longitudinal axis. Due to the asymmetrical attachment of the sensors can be closed due to geometric considerations on the impact location and the momentum transfer. In this case, both the amount and the direction of the impulse transfer can be determined.

From the DE 101 41 886 A1 a method for determining a release time for restraining means in a vehicle is known, in which the formation of two time windows for the speed reduction in a crash, the slope of the speed reduction in the respective time window and the position of the time window is determined in order in conjunction with a Impact time and the impact velocity to achieve an accurate determination of the tripping time.

These However, systems have the disadvantage that the acceleration signals the outsourced sensors only for looked at alone or evaluated, so only in a limited Measure with the Acceleration values of the centrally arranged sensors in proportion become an accident characteristic or accident detail information for optimizing the tripping behavior of an occupant protection system.

Object of the present invention is Therefore, to provide a method for triggering an occupant protection system for a vehicle and an occupant protection system, which ensure optimum occupant safety and are reliable and cost-effective.

These The object is achieved by a method having the features of claim 1 and by an occupant protection system having the features of claim 15 solved. Preferred embodiments of the invention will become apparent from the dependent claims.

One The essential idea of the invention is based on the knowledge that the determination of the type of accident allows a statement about the severity of the accident, whereby a targeted adaptation of the triggering behavior an occupant protection system can be made. To an optimal Protecting the occupants in the event of an accident can reduce the type of accident time before and at the latest with the triggering decision determined and used to adjust the tripping behavior.

The Type of accident is now based on the invention the sequence of collision signals from sensors, ie the temporal Occurrence of the transmitted by the sensors concerned collision signals determined. At least two sensors are required to detect the collision signals to generate. In particular, the time sequence of the collision signals one in a control unit an occupant protection system provided sensor and an assistance sensor, for example an upfront or satellite sensor, evaluated. It can also the temporal sequence of the collision signals from two outside of the control unit arranged sensors or provided by an internally in the control unit Sensor and two or more assistance sensors are evaluated.

Conceivable is the evaluation of the temporal sequence of different sensors, provided the crash signature delivered by the sensors is a temporal resolution which is suitable for determining the type of accident. The temporal Sequence is used to determine the type of accident, e.g. by doing it reproduces a pattern or history that is one of several stored accident types can be assigned. Under the collision signals The sensors become their operating signals in the event of a collision Understood. The sequence of collision signals can in particular determined by one or more thresholds, the which is or will be exceeded by the collision signals in an accident. The passing of the at least one threshold value generated by a collision signal Time event. Based on several such of different sensors generated time events then the accident type can be determined. The at least one threshold influences in particular the sensitivity of the system and can be adjustable.

to Adjustment of the tripping behavior is preferably a tripping time and / or a tripping threshold the at least one protective agent changed. The trip time is called the time in which the protective means of the occupant protection system, ie e.g. Airbag, belt tensioner or rollover protection device are triggered.

The Accident type is determined in particular on the basis of a transit time difference of at least two collision signals determined. To get a reliable classification be able to carry out the accident severity, has been shown that the transit time of a delay signal, measured between two locally spaced measuring points, as a criterion for accident characterization can be used. On this basis, the triggering behavior be influenced so that the protection means as efficiently as possible to use can be brought.

Prefers The accident includes a high-speed crash, a medium-speed crash and / or a low-speed crash. Of course, this division can continue be refined to an even more accurate adaptation of the triggering behavior to achieve.

in the Determining the type of accident can also additionally an impact direction be determined from the spatial Arrangement of the sensors on the vehicle can be determined, their collision signals were recorded. about the direction of impact is in particular an accident severity determinable, so that the protection means as possible can be used efficiently.

In In this case, the type of accident preferably includes a frontal crash, a side crash, a rear crash, an oblique crash and / or a roll-over crash.

Farther Each accident type can be assigned at least one reaction parameter be in the adjustment of the triggering behavior of the occupant protection system received. about the specification of various reaction parameters can be applied to any detected type of accident be reacting specifically.

The Reaction parameters preferably comprise a triggering threshold, an integration constant, an acceleration, a velocity, and / or a trip.

The values of the reaction parameters are here dimensioned in particular for optimum protection of the occupants. It can depend on the value of a parameter as well as the ratio of all Values arrive to each other for optimum protection.

Ideally is the distance of at least two sensors at least about 25 cm. It has been shown that such or even a greater distance Run-time differences of the collision signals causes for a safe Detection of the accident type are sufficient.

The Sensors can include one or more outsourced assistance sensors to ensure the detection to increase a type of accident.

Preferably the sensors are arranged on or in the region of the vehicle body.

The Sensors preferably include an acceleration sensor, a Rotation rate sensor, a strain gauge, a pressure sensor and / or a Magnetic sensor.

The The invention further relates to an occupant protection system for a vehicle with a control unit provided with at least one protective means, e.g. an airbag, and at least two locally spaced on the vehicle Sensors connected. The collision signals of the sensors become detected by the control unit and triggered to trigger the protection means. The Control unit is to carry out the invention Process trained. In particular, the functionality of the control unit is in Software realized. Among the at least two locally spaced on the vehicle Sensors are understood as sensors in different places are mounted in the vehicle. For example, this may be a sensor arranged in the control unit and an assistance sensor act in the side or front of the vehicle. Are conceivable Of course also other constellations, such as a sensor in the control unit and two assistant sensors or even just two or more assistant sensors, a sufficiently large distance to determine transit time differences have. Preferred for However, the invention is at least one sensor in the control unit and at least one sensor outside the control unit, since this meaningful temporal Sequences for the determination of the type of accident can be achieved.

Further Advantages and applications The present invention will become apparent from the following description in conjunction with the embodiments illustrated in the drawings.

In the description, in the claims, in the abstract and in the drawings are those in the listed below List of reference symbols used terms and associated reference numerals used.

The Drawings show in:

1 an embodiment of an arrangement of an occupant protection system for a motor vehicle with control unit and sensors;

2 a time course of several collision signals of different sensors in the event of an accident depending on the impact speed;

3 a block diagram of an embodiment of an evaluation unit for processing a sensor signal, and

4 an embodiment of a matrix of accident types, reaction parameters and their associated values according to the invention.

1 shows an arrangement of an occupant protection system for a motor vehicle 10 with control unit 20 and sensors 21 . 21 ' . 22 . 22 ' . 23 , The control unit 20 is central in the vehicle 10 , preferably arranged on the tunnel. With this controller 20 are not shown retaining means such as belt tensioners, airbag and rollover protection devices connected, which are activated in the event of a crash or other critical driving situation for the most efficient protection of the occupants.

In the laterally arranged on the vehicle assistance sensors 21 . 21 ' These are so-called side sensors, which are mainly needed for the detection of a side crash or an accident situation in which the force mainly takes place laterally. Thus, a corresponding type of accident can be detected at an early stage in order to activate the necessary protection means.

At the front of the vehicle 10 arranged assistance sensors 22 . 22 ' These are so-called upfront sensors, which are mainly needed to detect a frontal crash or an accident situation in which the force mainly occurs from the front. Thus, a corresponding type of accident can be detected at an early stage in order to activate the necessary protection means. Depending on the type of vehicle, it may be necessary to have two upfront sensors for reliable recording of the type of accident 22 . 22 ' , are arranged eccentrically to the vehicle longitudinal axis, are provided, or that as a result of the vehicle structure already a single upfront sensor 23 , Preferably centered to the vehicle longitudinal axis, for reliable detection of the collision situation is sufficient to make the required Kollisionssig nale to generate.

Of the completeness It should be noted that the measuring principles of the assistance sensors are around accelerometers, pressure sensors, strain gages, magnetoresistive sensors, etc., as well as yaw rate sensors (yaw rate sensors) can act, depending on the installation generate different collision signals.

2 shows a time course of several collision signals depending on the impact velocity and sensor arrangement. The illustrated typical signal curves are attributable to the following accident types by impact velocity and impact direction. The waveform V1 corresponds to a typical collision signal of an upfront sensor in a high-speed crash. The waveform V2 corresponds to a typical collision signal of a central sensor at the tunnel in a high-speed crash. The waveform V3 corresponds to a typical collision signal of an upfront sensor in a low-speed crash. The waveform V4 corresponds to a typical collision signal of a center sensor in a low-speed crash. Analogously, a characterization of the rollover crash types is possible, which are not graphed here in detail.

considered the resulting from a low-speed crash working signals V3 (upfront sensor) and V4 (tunnel sensor), it can be seen that the two collision signals for exceeding a threshold S1 relatively far apart in time, which is a long one Signal transit time in a low-speed crash equivalent. Thus, conversely, with a relative time-wise wide Distance of times to each other, in which the collision signals exceed the threshold S1, on an accident with low-speed characteristics getting closed.

considered on the other hand, the collision signals V1 resulting from a high-speed crash (Upfront sensor) and V2 (tunnel sensor), it can be seen that the two collision signals to exceed a threshold S1 are relatively small in time from each other, which is one short signal propagation time in a high-speed crash corresponds. Consequently can turn back to a temporally relative low Distance of times to each other, in which the collision signals exceed the threshold S1, be closed to an accident with high-speed features.

Due to the diagnosed type of accident, for example, with the aid of a stored in the system matrix, as in 4 shown, a tripping threshold used as a triggering criterion are derived to bring the occupant protection device as efficiently as possible to use.

In an analogous manner, it behaves in a rollover process, which is not shown in detail graphically. The sensors detecting a rollover process emit a corresponding collision signal on rotational movements or rotational acceleration movements, from which, with the aid of a matrix stored in the system, similar to those in FIG 4 represented matrix can be derived as a tripping criterion used tripping threshold to bring the occupant protection device as efficiently as possible to use.

Of the Minimum distance to be compared in terms of their collision signals Sensors is Here at least about 25 cm to each other, so in the sense of a reliable evaluation significant differences can be generated.

3 shows a block diagram of an evaluation unit 30 for processing a sensor signal. In this case, the output signal a (t) of a sensor 21 . 21 ' . 22 . 22 ' . 23 for detecting accelerations an integrator 31 fed. The output signal of the sensor 21 . 21 ' . 22 . 22 ' . 23 can be used for feedback purposes of the integrator 31 a certain reset value (starting from zero) or an offset signal 24 as a fixed value in g or if required as a variable value according to 4 subtracted from. At the output of the integrator 31 there is a speed 25 in the form v (t) for further utilization. The speed 25 becomes a comparator 32 supplied, which includes a tripping threshold value used as a triggering criterion, by a value transmitter 33 can be variably adapted to the requirements. Before the speed 25 This may be for return purposes, in the case of another, not shown here integration or for adjustment purposes to the diagnosed accident type, again a certain value (starting from zero) or an offset signal 26 as a fixed value in m / s or if required as a variable value according to 4 be subtracted. Another possibility of influencing the tripping behavior is that instead of the triggering threshold in the comparator 32 or the reset values 24 . 26 an integration constant K of the integrator 31 by another value transmitter 34 is controlled to perform an adjustment to the diagnosed accident.

At the output of the comparator 32 If an activation threshold value is used as a triggering criterion, an enable signal for the protection means is generated, optionally with further enable signals 27 can be linked.

4 shows a matrix of accident types, reaction parameters and their associated values. Due to the according to 2 determined signal propagation time, conclusions can be drawn on the type of accident based on the matrix stored in the system in order to derive the corresponding values of the reaction parameters, which are used for the most efficient use of the protection means in the determination of the tripping time.

In a high-speed crash, it is advantageous if the tripping threshold used as a triggering criterion is lower than in comparison to a low-speed crash. Instead of the triggering threshold can also, as in the 3 discussed, the integration constant will be adapted to the type of accident. In this case, it is advantageous that a higher integration constant is used in a high-speed crash than in comparison to a low-speed crash. It is equally advantageous if the reset values 24 . 26 be adapted to the diagnosed type of accident according to the matrix.

Of the completeness It should be noted that it is the collision signals to be compared not necessarily must be a sensor signal of a central sensor, but it also quite by two or more collision signals from outsourced Act sensors with the same or different principle of action can.

10

motor vehicle

11

preservative

20

control unit

21 21 '

side sensor

22 22 '

front sensor

23

central front sensor

24 26

Reset value

25

speed

27

enable signal

30

evaluation

31

integrator

32

comparator

33 34

valuator

at)

output a sensor

G

acceleration

v (t)

speed information

V1, V2, V3, V4

waveform

Z1, Z2

Time difference

Claims (16)

Method for triggering an occupant protection system for a vehicle ( 10 ), with at least two sensors ( 21 . 21 ' . 22 . 22 ' . 23 ) for triggering at least one protective agent ( 11 ) in an accident of the vehicle, characterized in that a time sequence of collision signals (V1, V2, V3, V4) of the sensors ( 21 . 21 ' . 22 . 22 ' . 23 ) and used to determine an accident type, wherein the determined type of accident is used to adjust the tripping behavior of the occupant protection system. A method according to claim 1, characterized in that for adapting the tripping behavior, a tripping time and / or a tripping threshold of the at least one protection means ( 11 ) is changed. Method according to claim 1 or 2, characterized that the type of accident based on a transit time difference (Z1, Z2) of at least two collision signals (V1, V2, V3, V4) is determined. Method according to claim 3, characterized that the accident type a high-speed crash, a medium-speed crash and / or a low-speed crash. Method according to one of the preceding claims, characterized in that for determining the type of accident, an impact direction is determined, which consists of the spatial arrangement of the sensors ( 21 . 21 ' . 22 . 22 ' . 23 ) can be determined on the driving tool whose collision signals (V1, V2, V3, V4) were detected. Method according to claim 5, characterized in that that the accident type a frontal crash, a side crash, a Rear crash, a slanted crash and / or a rollover crash includes. Method according to one of the preceding claims, characterized characterized in that each type of accident at least one reaction parameter associated with the adaptation of the tripping behavior of the occupant protection system received. Method according to claim 7, characterized in that that the reaction parameters have a triggering threshold, an integration constant, an acceleration, a speed, and / or a position feedback include. Method according to claim 7 or 8, characterized that the values of the reaction parameters for optimum protection of the occupants are measured. Method according to one of the preceding claims, characterized in that the distance from at least two sensors ( 21 . 21 ' . 22 . 22 ' . 23 ) is at least about 25 cm. Method according to one of the preceding claims, characterized in that the sensors ( 21 . 21 ' . 22 . 22 ' . 23 ) comprise one or more outsourced assistance sensors. Method according to one of the preceding claims, characterized in that the sensors ( 21 . 21 ' . 22 . 22 ' . 23 ) are arranged on or in the region of the vehicle body. Method according to one of the preceding claims, characterized characterized in that the sensors include an acceleration sensor, a Rotation rate sensor, a strain gauge, a pressure sensor and / or comprise a magnetic sensor. Method according to one of the preceding claims, characterized in that the at least one protective agent ( 11 ) is an airbag, belt tensioner and / or roll bar. Occupant protection system for a vehicle, with a control unit ( 20 ) containing at least one protective agent ( 11 ) and at least two locally spaced sensors ( 21 . 21 ' . 22 . 22 ' . 23 ) whose collision signals (V1, V2, V3, V4) from the control unit ( 20 ) and to trigger the protective device ( 11 ), characterized in that the control unit ( 20 ) is designed for carrying out the method according to one of the preceding claims. Occupant protection system according to claim 16, characterized in that the functionality of the control unit ( 20 ) is realized in software.