DE102004008602A1 - Triggering method for a passenger protection system in a motor vehicle uses a swivel rate sensor to record the vehicle's swivel rates on a longitudinal/transverse axis - Google Patents

Abstract

Rates of swivel in a motor vehicle are recorded and evaluated regarding the vehicle's position by relying on additional information independent of a swivel rate sensor. Swivel rates are evaluated at the beginning of a roll-over process. An initializing phase signal (IPS) is fed to reset devices that restore integration during an active IPS by feeding a reset pulse to an integrator. An independent claim is also included for a device for triggering a passenger protection system in a motor vehicle.

Description

The The invention relates to a method for triggering an occupant protection system of a vehicle according to the preamble of claim 1 and a corresponding device according to claim 14.

safety is playing an increasingly important role in the automotive industry, what about it shows that now an airbag is standard equipment of a modern Motor vehicle belongs. While airbags and pretensioners, which are impact protection systems, one Market penetration of almost 100% has been achieved, this is the case automatic rollover protection Activating accidental rollovers is not yet the case.

Accidental rollover events are characterized by rotations of the vehicle about its longitudinal and transverse axis. For timely release of vehicle occupant protection systems in such rollover events it requires, on the one hand, a rotation of the vehicle about one his axes is recognized in time and on the other hand the means Rotary sensors measured roll and pitch angles of the actual Angular position of the vehicle corresponds. Problematic here are however, offset errors from gyroscope sensors that cause a faulty one Determining the angular position of the vehicle can lead.

The EP 1 089 898 discloses a method for the exact determination of a rolling process leading to a critical angular position of a vehicle, in which an offset error in a rotation rate measurement is largely suppressed. This is achieved by two measures: firstly, an output of a yaw rate sensor is only then integrated and thus included in the deployment decision for a rollover protection system, when the signal exceeds a lower spin rate threshold and is also below an upper spin rate threshold; the thresholds can be specified depending on an offset error of the sensor. Second, after a predetermined reset time, integration of an output signal of a rotation rate sensor is aborted and restarted. The starting situation is the initial state where the resting conditions of the starting conditions are zero or nearly zero. This is to preclude that arise by the ongoing integration angle, which have a strongly deviating from the actual angular position high value, which is interpreted as a not true in reality rollover.

Besides that is It's known starting criteria for one Algorithm for processing signals from yaw rate sensors and to trigger of an occupant protection system not just from one identified at the beginning static offset rate error, but the offset error continuously by a determined during an initialization "static" offset error and additionally by another dynamic, respectively tracked, compensation value to suppress.

Both However, processes have the disadvantage that in the case of an accident, for example, upside down stationary vehicle, the sensor in an initialization phase a Offset error detected, although correct for the upside down vehicle, but for the on the normal operation of the vehicle equipped passenger protection system wrong is. This "wrong" offset error will now the occupant protection system sensitized so that it comes to false alarms can if a vehicle returns to its proper after an accident Position is brought and guards such. a rollover protection device until then not triggered were.

Around against such false triggering to become more robust beats WO 02/20314 before, additional Information such as "Strut Sprung "in the triggering decision to involve. However, this information is in the trigger decision timed, if the algorithm for the decision already is active, i. already active is ready to trigger. From the point of view From a security point of view, this late involvement has some bearing on it Danger potential in itself, as the triggering decision is delayed can.

task The present invention is therefore a method and a Device for triggering to propose an occupant protection system of a vehicle that is less is susceptible to malfunctioning and offers a high safety standard.

These The object is achieved by a method for triggering an occupant protection system a vehicle having the features of claim 1 and by a corresponding device with the features of claim 14 solved. preferred Embodiments of the invention will become apparent from the dependent claims.

An essential concept of the invention is to improve the robustness against false triggering in a method for triggering an occupant protection system of a vehicle in that additional rotational-rate sensor-independent information relating to the position of the driving in the triggering decision is influenced by the fact that depending on it an evaluation, in particular integration of a detected by a rotation rate sensor yaw rate is released. Once the release has taken place, only accident-relevant and rotational-rate sensor-dependent information enter into the triggering decision, whereby a possible triggering is not delayed by an additional plausibility check of yaw-rate sensor signals after occurrence of an accident-relevant event as in the method according to WO 02/20314. In contrast to WO 02/20314, therefore, not another rotational-rate sensor-independent information is used as a triggering criterion, but rather as a start-up criterion or, more precisely, as an enabling criterion for the triggering algorithm of an occupant protection system, whereby the temporal behavior of the triggering algorithm is substantially improved. By including a rotation rate sensor-independent information regarding the position of the vehicle in the triggering decision can also be avoided that in certain situations, a triggering takes place, for example when erecting a roll-over vehicle in which an occupant protection system such as an automatic rollover bar has not been triggered. This may be the case, for example, when a vehicle turns over its transverse axis or rolls over in such a way that it is not sensed by an occupant protection system.

Under a rollover process or a rolling over of the vehicle, any rotation of the vehicle about its lateral and / or longitudinal axis understood. In this case, the vehicle does not necessarily have to be in an inverted position to lie down, so on his roof. Rather, it is here below a rollover process also tilting the vehicle to one side, e.g. if a truck tilts to the side, or a rollover a vehicle understood about its transverse axis.

The The invention now relates to a method for triggering an occupant protection system a vehicle, wherein at least one rotation rate sensor the rotation rate of the vehicle about its longitudinal axis and / or Transverse axis detected and the detected rate of rotation evaluated and a Threshold decision supplied is to be able to recognize a critical angular position of the vehicle. The Evaluation of the rotation rate will depend on at least one additional rotation-rate sensors independent Information regarding the location of the vehicle released. This will prevent that can trigger the occupant protection system in certain positions of the vehicle, for example, if the vehicle after a rollover on his roof or on the page.

Preferably is the evaluation of the rotation rate at the beginning of a rollover process released at a time to that of the occupant protection system it is recognized that a possible rollover process starts.

The Evaluation of the yaw rate can also be done after the end of an initialization phase the at least one rotation rate sensor or at a transition in an active trip mode of the occupant protection system. This will make the plausibility check at a certain defined time rather than after WO 02/20314 made shortly after occurrence of an accident-relevant event, whereby the safety standard is significantly improved. Besides, we this increases the robustness against false triggering.

Finally, can the evaluation can also be released cyclically. It means that a release decision is made at predetermined times, for example, every few seconds. Has the location of the vehicle changed e.g. After an accident, this new location can then be followed by one Approved release decision and, where appropriate, triggering the occupant protection system prevent.

Preferably the evaluation of the rotation rate is continuously recycled and / or aborted after a presettable reset time and restarted, in order to avoid that a wrong turning rate by a continuous Evaluation, in particular integration is increased.

at the gyroscope-independent Information may be, for example, a sensor signal of a Spring travel sensors act. With the spring travel sensor can be measured whether the chassis of the vehicle is loaded or unloaded. The Evaluation, in particular integration of the rotation rate can then, for example only in the presence of a given load on the chassis released, e.g. if the vehicle is in a non-critical or normal situation and / or situation or if a rollover process starting from a normal position of the vehicle begins.

alternative or additionally For example, the rotational rate sensor-independent information may be a sensor signal act of an acceleration sensor. This can be done that, for example, at one of a given waveform) more or less strongly deviating acceleration signal none Release takes place.

The acceleration sensor preferably detects the accelerations of the vehicle in the Z direction, that is to say essentially acceleration forces of gravity. Based on the sign of the sensori gnals can be determined, for example, whether the vehicle is overturned after a rollover process. If the sensor signal indicates that the vehicle has overturned, ie is "upside down", it is possible to prevent the evaluation, eg an integration, from being released in order to prevent the triggering of an as yet unreleased occupant protection system when setting up the vehicle.

alternative or additionally For example, the rotation rate sensor-independent information may be a sensor signal act of a gravity-based sensor. With a Gravity sensor, such as a contact ball or a Contact switch, can be determined very easily whether the vehicle is in a normal position or overturned.

Preferably If the rotation rate sensor-independent information is a sensor signal an information source, which by means of a vehicle information bus, e.g. above a CAN bus, available is provided.

alternative or additionally For example, the spin rate sensor independent information may be predominantly while and / or exclusively while The information generated in the initialization phase act. Thereby In the release, mainly current information is considered.

alternative or additionally For example, the spin rate sensor independent information may be one exclusively before a new accident event and / or raising the vehicle generated information, for example, to prevent a "head position" of the vehicle after a rollover process is assumed as the normal position of the vehicle. In particular, acts this is a generated before the next accident event and stored rate of rotation sensor independent information, if they for the Release of the integration of the rotation rate is relevant.

Especially the rate of rotation is only evaluated if it has a exceeds lower turn rate threshold and in particular lies below an upper rotation rate threshold, the threshold (s) depending on of an offset error of the respective rotation rate sensor symmetrical or is given asymmetrically or become. This avoids that disorders be interpreted as a rotation rate in sensor signal.

Further The invention relates to a device for triggering an occupant protection system a vehicle, with at least one rotation rate sensor for detecting the rate of rotation of the vehicle about its longitudinal axis and / or transverse axis, at least one source of information for at least one rotation rate sensor independent information in terms of the position of the vehicle, at least one evaluation unit for evaluation the rate of rotation recorded, and decision making means that the evaluated Rate of rotation supplied is to be able to recognize a critical angular position of the vehicle. moreover Release means are provided, which are designed for evaluation the rate of rotation by the evaluation unit in dependence on the at least An additional rotation-rate sensors independent Information regarding release the position of the vehicle.

Especially the release agents are designed to end the evaluation an initialization phase of the at least one rotation rate sensor or at a transition in an active trip mode of the occupant protection system.

Farther can Reset means be provided, which are adapted to the evaluation of the rotation rate continuously recirculate and / or after abort a definable reset time and restart.

Preferably the at least one source of information is a spring travel sensor Accelerometer or a gravity-based sensor.

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 a diagram showing the course of important thresholds of a first embodiment of the triggering algorithm according to the invention,

2 a diagram showing the course of important thresholds of a second embodiment of the triggering algorithm according to the invention,

2 a diagram showing the course of important thresholds of a third embodiment of the triggering algorithm according to the invention,

4 the diagram of 1 with the course integration signal; and

5 a block diagram of an embodiment of an inventive device for triggering an occupant protection system of a vehicle.

1 shows a diagram of the course of important thresholds of a triggering algorithm during an initialization phase of a rotation rate sensor and an active operation of an occupant protection device. The active operating range) follows immediately after the initialization phase. During the initialization phase, the rotation rate sensor and the associated signal processing electronics are checked for functionality by a self-diagnosis or a self-test, and an offset value "Offset-ACTUAL" of the rotation rate sensor is determined.

On the ordinate axis is an "offset target" and symmetric arranged rotation rate thresholds + ωo, -ωo, + ωu, -ωu shown. By the rotation rate thresholds Functional areas of the triggering algorithm are defined, in which as an evaluation form an integration of the sensor signal the rotation rate sensor takes place. Is the sensor signal of the rotation rate sensor in a range between the thresholds + ωu, -ωu or within of the absolute value distance ω to the "offset target mark", no integration takes place the yaw rate so as not to hinder any noise from the sensor Sensors and every disturbance event to react with the start of the algorithm. Within the ranges between the thresholds + ωo, + ωu or -ωu, -ωo takes place an integration of the rotation rate sensor output signal, since The position of a vehicle is significantly different from its normal operating position must distinguish, so that the rotary knob sensor such a signal generated. In this case, it can be assumed that it is a fault act, for example, was triggered by a rollover of the vehicle. Outside the limits + ωo, -ωo takes place no integration of the rotation rate sensor output signal, as in this Area not covered by a properly functioning sensor can be displayed, it can be assumed that it is an error in the rotation rate sensor output signal.

As in 1 2, the thresholds + ωo, + ωu, -ωo and -ωu are shifted in active operation from the initialization phase. The shift is due to the fact that an offset of the rotation rate sensor is detected in the initialization phase of a test electronics, determined in size and then compensated in the active operating range by the thresholds + ωo, + ωu, -ωo and -ωu are moved accordingly. Due to the offset error present in practice in the case of virtually any rate of rotation sensor, the aforementioned symmetrical working limits would no longer exist without such a correction. Due to the shift around the previously determined offset error, the symmetry is restored at the end of the initialization phase or during the transition from the initialization phase to the active triggering mode.

In the diagram in 2 are not the thresholds + ωo, + ωu, -ωo and -ωu shifted, but it is at the end of the initialization phase or at the transition to active operation, the actual output signal position shifted to the desired output signal position by the actual signal of the rotation rate sensor of the previously determined offset error is added or subtracted (depending on the sign of the offset error).

The diagram of 3 points further to the diagram of 1 in that a continuous error correction of the working limits or thresholds + ωo, + ωu, -ωo and -ωu can also be carried out as a function of the continuous offset error during the active triggering operation. A continuous offset error occurs, for example due to temperature influences on the rotation rate sensor over the operating time. Analogous to 2 For example, the possibly occurring offset components may also be used to correct the magnitude of the actual output signal of the yaw rate sensor instead of correcting the thresholds + ωo, + ωu, -ωo and -ωu.

In the diagram of 4 is a possible working signal (integration signal) AS shown. An integration is always started when the rotation rate sensor output signal reaches or exceeds the above-described thresholds + ωo, + ωu, -ωo and -ωu and within the ranges defined for integration between the thresholds + ωo, + ωu, resp . -Ωu, -ωo is located.

A problem that the 4 is not readily apparent, consists in the exact return of the started operating signal AS (the once brought from rest position working signal), to its original output rest value, so that it can be started again for subsequent possibly accident-relevant events under the intended conditions, ie an integration can be subjected. The exact return to zero is problematic, since a turning operation of the vehicle is usually not limited to one axis, but almost always extends to several vehicle axles. Due to the superimposition of the rotational movement about several axes, therefore, the exact feedback is not always necessarily ensured.

In order to obtain an exact feedback of the working signal, it is therefore advisable (in addition to a continuous forced return) that after Expiration of a predefined time (in the 4 If, for example, three different times Z1, Z2 and Z3 are shown, each with different start criteria), the operation is aborted (in the diagram at time F after expiration of the forward-defined time period Z1 or Z2 or Z3). The start time (in the diagram of the time C or D or E) of the time periods Z1, Z2 and Z3 is by reaching an event (in the diagram exceeding the threshold + ωu or falling below the threshold + ωu or falling below the Offset actual value). In the case of the feedback indicated in the diagram by the arrow from F to A, all working signals are set to an initial value, as can be found after initialization.

This This is achieved by the during the last initialization phase values determined are used or by a new initialization pass is started to possibly existing drifts, especially in the sensor signal take into account the rotation wire sensor to be able to. However, these methods involve the following danger: when a vehicle is in an unexpected position (e.g. Side or roof position after a rollover process), one can still not triggered Occupant protection system when raising the vehicle to its original position or normal position may be trigger, because the turning back from the supposed "right Resting position "as a rollover is interpreted. Above all, this misconduct becomes even worse favors, that the acceleration due to gravity is generally not measured by DC-capable sensors.

• – einen Beschleunigungsaufnehmer in Z-Richtung (Messen der Erdanziehung – ein g mit dem richtigen Vorzeichen),
• – einen Federwegsensor (Messen ob Fahrwerk belastet oder unbelastet/ausgefedert) oder auch
• – einen einfachen Schwerkraftsensor (Kontaktschalter/Kontaktkugel) handeln.

In order to prevent such false tripping, therefore, a plausibility check is carried out at the end of the initialization phase or during the transition to the active tripping operation. The plausibility check is carried out in that at least one additional sensor signal, which is independent of a rotation rate sensor, is included in the decision about a release of the integration of the sensor signal of the rotation rate sensor. Based on such an additional rotation rate sensor independent sensor signal is now decided whether the transition at the end of the initialization phase or the new beginning with known previously determined parameters is permissible or not, ie can be released or can not be released. The additional sensor signals may be, for example

• - an accelerometer in the Z-direction (measuring the gravitational pull - a g with the correct sign),
• - A spring travel sensor (measuring whether chassis loaded or unloaded / rebounded) or also
• - act a simple gravity sensor (contact switch / contact ball).

Based these exemplified sensors can be easily and above all, determine in a timely manner whether the vehicle is at the beginning or at the transition in the triggering Condition is in a predetermined nominal position (nominal position / correct Initial state) or not.

With this additional Plausibility check in the initialization phase of a rotation rate sensor or during the transition into the active release readiness an occupant protection system that is independent of a rotation rate sensor works, will be an improvement in terms of a possible theoretical fault-triggering behavior reached. The improvement is aimed particularly at accident situations, in which the protective devices during the actual accident were not activated, and a subsequent false triggering due erection of the vehicle by e.g. Rescue workers still possible would.

5 shows a circuit arrangement which exemplifies the device according to the invention for triggering an occupant protection system of a vehicle.

The illustrated circuit arrangement comprises a rotation rate sensor 10 whose sensor signal is a threshold value decider 22 which is fed into the 1 - 3 implemented thresholds + ωo, + ωu, -ωo and -ωu and compares the sensor signal with these thresholds. The threshold decision maker 22 is an integrator 14 downstream, the sensor signal of the rotation rate sensor 10 if the integration is enabled and the threshold decision maker 22 the sensor signal "passes through." The integrated sensor signal is provided by the integrator 14 decision means 16 fed, which compare it with a critical angle and depending on the comparison result, a trigger signal 28 to trigger an occupant protection system such as an automatic roll bar. The decision-making means 16 are designed to be a trigger signal 28 generate when the angle corresponding to the integrated sensor signal, which substantially corresponds to the rotation angle of the vehicle exceeds a predetermined critical tilt angle. In this case, it was detected that the vehicle is in a rollover process.

However, an integrated sensor signal is provided by the integrator 14 only generated when the integration of release means 18 has been released, ie the integrator has been activated. The release agents 18 derive the decision to release the integration in particular from a sensor signal of a gravity sensor 12 regardless of the sensor signal of the yaw rate sensor 10 is produced. These are the release agents 18 with a CAN bus 26 of Connected vehicle via which they receive the signals of the gravity sensor 12 can receive. A received sensor signal of the gravity sensor 12 is processed as follows: the release agents 18 Compare the signal with a stored signal value, which corresponds approximately to a value that occurs in a normal position of the vehicle. Dodges the signal from the gravity sensor 12 From the stored value strongly, it can be assumed that the vehicle is not in normal position and is, for example, overturned, as after a rollover process. In this case, the release agents lock 18 the integrator 14 , so that the sensor signal of the rotation rate sensor 10 is no longer integrated and no trigger signal 28 can be generated. A triggering of the occupant protection system is thereby blocked, which prevents rescue workers when erecting the overturned vehicle can be injured by a sudden triggering occupant protection device. On the other hand, if the gravity sensor signal does not deviate significantly from the stored value, the integration of the release means 18 Approved.

The decision on a release of the integration by the release means 18 is performed, is not carried out continuously, but only after completion of an initialization phase of the rotation rate sensor 10 or at a transition to an active trip operation of the occupant protection system. For this purpose, the rotation rate sensor generates 10 or more precisely its signal processing electronics, an initialization phase signal 30 indicating whether the yaw rate sensor 10 is currently performing a self-test or initialization phase. Is the initialization phase signal 30 active, so lead the release agents 18 upon receiving a negative edge of the initialization phase signal 30 a release decision by, ie compare on the CAN bus 26 received signal of the gravity sensor 12 with the stored value, depending on which release the integration, as already explained above.

The initialization phase signal 30 will also reset 20 which is the integration when the initialization phase signal is active 30 reset, more specifically the integrator 14 apply a reset pulse. The reset means 20 implement in principle those associated with 5 explained the repatriation or replacement of the integration work process to prevent errors in the rotation rate from increasing in the course of ongoing integration. For this purpose, the reset means 20 also from a timer 24 triggered. The timer 24 is in turn triggered by the integrated rotary sensor signal as indicated by 4 and the times C, D and E, respectively, above. As soon as the integrated rotation sensor signal triggers an event such as at the times C, D or E, the timer is 24 starts and runs for a predetermined period of time, after which it sends a signal to the reset means 20 sends. The reset means 20 then put the integrator 14 and initiate an initialization phase of the rotation rate sensor 10 a (dashed line), which in turn causes the release agent 18 At the end of the initialization phase, make a new release decision of the integration.

The explained above Circuit arrangement can be realized, for example as an algorithm, that of a suitably powerful processor, in particular Signal processing and microprocessor is executed as ASIC (Application Specific Integrated Circuit) or by standard components, the according to the required functions - release decision, Reset, integration, Threshold decision - programmed are.

10

Yaw rate sensor

12

Gravity sensor

14

integrator

16

decision means

18

release means

20

Reset means

22

threshold value

24

timer

26

CAN bus

28

trigger signal

30

Initialisierungsphasensignal

Claims (17)

A method for triggering an occupant protection system of a vehicle, wherein at least one rotation rate sensor detects the rate of rotation of the vehicle about its longitudinal axis and / or transverse axis and the detected rate of rotation is evaluated and a threshold value decision is made to detect a critical angular position of the vehicle, characterized in that the evaluation of the rotation rate is released in dependence on at least one additional rotational-rate sensor-independent information relating to the position of the vehicle. Method according to claim 1, characterized in that that the evaluation of the rotation rate at the beginning of a rollover process is released. Method according to claim 1 or 2, characterized that the evaluation of the rotation rate after the end of an initialization phase the at least one rotation rate sensor or at a transition in an active trip mode of the occupant protection system. Method according to claim 1, 2 or 3, characterized the evaluation of the yaw rate is enabled cyclically. Method according to one of claims 1 to 4, characterized that the evaluation of the rate of rotation is continuously recycled and / or aborted after a presettable reset time and restarted becomes. Method according to one of claims 1 to 5, characterized in that the rotational-rate sensor-independent information is a sensor signal a spring travel sensor acts. Method according to one of claims 1 to 6, characterized in that the rotational-rate sensor-independent information is a sensor signal an acceleration sensor acts. Method according to claim 7, characterized in that that the acceleration sensor the accelerations of the vehicle recorded in Z-direction. Method according to one of claims 1 to 8, characterized in that the rotation rate sensor-independent information is a sensor signal a gravity based sensor. Method according to one of claims 1 to 9, characterized in that the rotation rate sensor-independent information is a sensor signal an information source, which by means of a vehicle information bus to disposal is provided. Method according to one of claims 3 to 10, characterized that the rotation rate sensor independent information is predominantly while and / or exclusively during the Initialization phase and / or self-diagnosis generated information is. Method according to one of claims 1 to 11, characterized that the rotation rate sensor independent information is one exclusively a new accident event and / or erecting the vehicle generated information is. Method according to one of claims 1 to 12, characterized that the yaw rate is subjected to evaluation only if it exceeds a lower rate of turn threshold and in particular below an upper slew rate threshold, the threshold (s) dependent on of an offset error of the respective rotation rate sensor symmetrical or is given asymmetrically or become. Device for triggering an occupant protection system of a vehicle, having at least one rotation rate sensor ( 10 ) for detecting the rate of rotation of the vehicle about its longitudinal axis and / or transverse axis, at least one information source ( 12 ) for at least one rotation sensor-independent information regarding the position of the vehicle, at least one evaluation unit ( 14 ) for evaluating the detected rate of turn, and decision-making means ( 16 ), to which the evaluated rate of rotation is fed in order to be able to recognize a critical angular position of the vehicle, characterized by release means ( 18 ), which are designed to enable the evaluation of the rotation rate by the evaluation unit ( 14 ) in response to the at least one additional yaw sensor independent information regarding the location of the vehicle. Device according to claim 14, characterized by the release means ( 18 ) are designed to release the evaluation after the end of an initialization phase of the at least one rotation rate sensor or at a transition to an active trip operation of the occupant protection system. Apparatus according to claim 14 or 15, characterized by reset means ( 20 ), which are designed to continuously recirculate the evaluation of the rotation rate and / or abort after a predefinable reset time and restart. Apparatus according to claim 14, 15 or 16, characterized in that the at least one information source ( 12 ) is a spring travel sensor, an acceleration sensor or a gravity-based sensor.