DE102009026926B4 - Method and control device for driving a personal safety device of a vehicle - Google Patents

Abstract

A method (700) for driving a personal safety device (200) of a vehicle (100), the method (700) comprising the following steps: - receiving (710) a sensor signal from a capacitive sensor (190), the sensor signal being a speed of a part (420) of the vehicle (100) towards the sensor (190); and enabling (720) or triggering the personal security means (200) when the sensor signal represents a speed greater than a predetermined threshold, characterized by further comprising a step of obtaining a second sensor signal from a second capacitive sensor another sensor signal corresponds to a speed of a part (420) of the vehicle (100) in the direction of the second sensor, wherein the second sensor is arranged at a different location in the vehicle than the sensor, and wherein the step of releasing (720) or triggering further on the Based on the second sensor signal.

Description

State of the art

The present invention relates to a method according to claim 1, a control device according to claim 7, a computer program product according to claim 8 and a unit for triggering or releasing a personal safety device of a vehicle according to claim 9.

• - ein Triggersignal, mit höherer Auslöseschwelle und
• - ein Plausibilitätssignal, mit niedrigerer Auslöseschwelle.

In the event of a vehicle accident - and the resulting accident severity - irreversible safety systems are triggered, among other things, to protect the occupants (airbag, belt tensioner, belt force reducer, etc.). In such a trip, the decision is often made via two sensor signals:

• a trigger signal with a higher triggering threshold and
• - a plausibility signal, with a lower tripping threshold.

• - einem Upfront-Sensor (Beschleunigungssensor für x-Richtung im Frontbereich des Fahrzeugs)
• - einem PAS (PAS = peripheral acceleration sensor = peripherer Beschleunigungssensor in x- oder x- und y-Richtung in der Fahrzeugseite)
• - einem PPS (PPS = peripheral pressure sensor = peripherer Drucksensor in der Fahrzeugseite)
• - einem Airbag-Steuergerät (d.h. insbesondere Beschleunigungssensoren darin, die in x- oder x- und y- Richtung eventuell auch unter 45° verbaut sind).

These signals usually come from different crash sensors (ie accident sensors) such as:

• an upfront sensor (x-direction acceleration sensor in the front of the vehicle)
• a PAS (peripheral acceleration sensor = peripheral acceleration sensor in the x or x and y direction in the vehicle side)
• a PPS (PPS = peripheral pressure sensor in the vehicle side)
• - An airbag control unit (ie in particular acceleration sensors therein, which may be installed in the x or x and y direction, even below 45 °).

This use of trigger and plausibility signals is advantageous to exclude false triggering; Depending on requirements, sensors can provide trigger or plausibility signals in individual cases; a fundamentally fixed assignment which sensor is used as a trigger signal or as a plausibility signal does not exist. From the systems AB8 and AB9 which serve the control of restraining means on the basis of sensor signals is known a triggering algorithm for the side crash, which based on the y-signal of the central device makes its triggering decision.

Also known are capacitive predictive distance sensors (eg from the GB 240 44 43 A ), which monitor the exterior of vehicles to detect an imminent collision.

Out EP 1 747 946 A1 For example, a magnetic crash sensor is known that is located within the door and senses a position of the intruding door panel in side collisions.

• - eine Kollision nach FMVSS 214 neu (oder „oblique pole test“ genannt). Dabei wird das Fahrzeug nicht wie üblich im 90°, sondern im 75° Winkel mit 32 km/h auf einen Pfahl dirigiert. Dabei wird das Fahrzeug so positioniert dass das Pfahl direkt auf Kopfhöhe des Fahrers einschlagen soll. Da sich die stabilisierende A -Säule weit weg vom dem Aufprallort befinden, ist eine hohe Intrusion und somit ein hoher Verletzungsrisiko zu erwarten.
• - Eine Kollision gemäß einem IIHS-Seitenaufprall: Es handelt sich hier um einen Barrierentest, wobei die Barrierenstruktur der eines SUV-Fahrzeuges (SUV = sports utility vehicle = Geländewagen) entspricht. Gegenüber einem üblichen Seitencrash mit Barriere hat der IIHS-Test eine höhere Masse und eine höhere Barriere, die mehr Bodenfreiheit aufweist. Dies bedeutet, dass die Intrusion des Objekts in das Fahrzeug über dem Schweller eingeht. Der sehr steife und dadurch stabilisierende Schweller hat hier nur sehr wenig Einfluss beim Unfallgeschehen. Dies kann zu einem erhöhten Verletzungsrisiko führen.

From the legal side-crash requirements and very important consumer tests, two very difficult tests are very important:

• - a collision according to FMVSS 214 new (or "oblique pole test" called). Here, the vehicle is not directed as usual in 90 °, but at a 75 ° angle at 32 km / h on a pole. The vehicle is positioned in such a way that the post should strike directly at the driver's head height. Since the stabilizing A-pillar is far away from the impact site, a high intrusion and thus a high risk of injury is to be expected.
• A collision in accordance with an IIHS side impact: This is a barrier test, the barrier structure corresponding to that of an SUV vehicle (SUV = sports utility vehicle = off-road vehicle). Compared to a standard side crash with barrier, the IIHS test has a higher mass and a higher barrier, which provides more ground clearance. This means that the intrusion of the object enters the vehicle above the sill. The very stiff and thus stabilizing sill has very little influence on the accident. This can lead to an increased risk of injury.

In the prior art, information about the impact location, i. the point of collision in case of side collisions is insufficiently taken into account in the determination of the triggering decision. For this reason, restraining means are sometimes activated unnecessarily, even though they have no positive influence on the injury values of the occupants at a given impact location. On the other hand, one is forced to reduce the sensitivity of the system in order not to make the number of such unwanted tripping too large, which in case of a necessary activation of restraints valuable time is lost and the occupant does not get the best possible protection an algorithm subsequently carried out differentiation according to crash severity and occupant danger to high expenditure in the data processing and a high system complexity.

In order to solve the above-mentioned problems, a triggering of restraint means, preferably in a side crash, should take place so that on the one hand the occupant experiences the best possible protection in a side collision, but on the other hand unnecessary, Cost-causing, triggering can be prevented. At the same time the necessary evaluation logic and a sensor for the provision of the corresponding sensor signals should be implemented in a simple and cost-effective manner.

The publication DE 42 42 230 A1 discloses a sensor device for detecting a side impact on a motor vehicle.

Disclosure of the invention

Against this background, the present invention provides a method, furthermore a control unit which uses this method, a corresponding computer program product and finally a unit according to the independent patent claims. Advantageous embodiments emerge from the respective subclaims and the following description.

• - Empfangen eines Sensorsignals von einem kapazitivem Sensor, wobei das Sensorsignal einer Geschwindigkeit eines Teils des Fahrzeugs in Richtung des Sensors entspricht; und
• - Freigeben oder Auslösen des Personensicherheitsmittels, wenn das Sensorsignal eine Geschwindigkeit repräsentiert, die größer als ein vorbestimmter Schwellwert ist.

The present invention provides a method for controlling a personal safety device of a vehicle, the method comprising the following steps:

• - Receiving a sensor signal from a capacitive sensor, wherein the sensor signal corresponds to a speed of a part of the vehicle in the direction of the sensor; and
• - releasing or triggering the personal security means when the sensor signal represents a speed which is greater than a predetermined threshold value.

The present invention further provides a control device which is designed to carry out or implement the steps of the method according to the invention. Also by this embodiment of the invention in the form of a control device, the object underlying the invention can be achieved quickly and efficiently.

In the present case, a control device can be understood as meaning an electrical device which processes sensor signals and outputs control signals in dependence thereon. The control unit may have an interface, which may be formed in hardware and / or software. In the case of a hardware-based design, the interfaces can be part of a so-called system ASIC, for example, which contains various functions of the control unit. However, it is also possible that the interfaces are their own integrated circuits or at least partially consist of discrete components. In a software training, the interfaces may be software modules that are present, for example, on a microcontroller in addition to other software modules.

Also of advantage is a computer program product with program code, which is stored on a machine-readable carrier such as a semiconductor memory, a hard disk memory or an optical memory and is used to perform or control steps of the method according to one of the embodiments described above, when the program on a control unit or a data processing system is executed.

• - einen kapazitiven Sensor, der ausgebildet ist, um eine Geschwindigkeit kapazitiv zu erfassen, mit der sich ein Teil des Fahrzeugs auf den Sensor zu bewegt, wobei der Sensor ferner ausgebildet ist, um ein Signal bereitzustellen, das die erfasste Geschwindigkeit repräsentiert; und
• - eine Auswerteeinheit zum Empfang des Signals des Sensors, wobei die Auswerteeinheit ausgebildet ist, um ein Personensicherheitsmittel des Fahrzeugs auszulösen oder freizugeben, wenn das empfangene Signal eine Geschwindigkeit repräsentiert, die größer als ein vordefinierter Schwellwert ist.

The present invention also includes a unit for triggering or releasing a personal security device of a vehicle, the unit having the following features:

• a capacitive sensor configured to capacitively detect a speed at which a portion of the vehicle is moving toward the sensor, the sensor further being configured to provide a signal representing the sensed speed; and
• an evaluation unit for receiving the signal of the sensor, wherein the evaluation unit is designed to trigger or release a personal safety device of the vehicle if the received signal represents a speed that is greater than a predefined threshold value.

The present invention is based on the recognition that the position of an impact of an object on the vehicle can then be adequately taken into account when the release or release of the personal security means takes place on the basis of a speed with which a part of the vehicle approaches a sensor emotional. As a result of the impact of the object on the vehicle, part of the vehicle is pressed into the vehicle at the position of the impact, so that the change in the distance between this vehicle part and the sensor can be detected. The fastest change in distance will be when the object hits the vehicle in the immediate vicinity of the sensor. If the object enters the vehicle at a position farther from the sensor, the change in the distance of the vehicle part from the sensor will be slower due to geometrical conditions or an expansion of the vehicle material. Now, if the mounting position of the sensor in the vehicle is known, can be easily detected by the evaluation of the speed of the vehicle part to the sensor, the place of impact of the object or better said the removal of the impact to the sensor in the vehicle. In this context, a location of the impact is to be understood in particular as the removal of the impact from the attachment position of the sensor on the vehicle. When the sensor is attached to a position of the vehicle in which an impact An object on the vehicle brings a very high risk of injury, thus an early triggering in collisions with high risk of injury can take place.

The present invention offers the advantage that a large added benefit in the detection of collisions with high risk of injury is possible by a very simple sensor arrangement and a very simple evaluation of such a sensor signal. In particular, the use of a capacitive sensor allows by its simple structure, a cost-effective implementation of the approach presented. The comparison of a sensor signal with a predetermined threshold also allows a very simple evaluation logic.

A complicated and thus time-consuming determination of an accident severity can be avoided.

It is favorable if, in the step of receiving, a sensor signal is received which is arranged in a lateral vehicle door, the sensor signal corresponding to a speed of a part of the vehicle door in the direction of the sensor. Especially with lateral impacts of objects in the vehicle there is a high risk of injury, since there is a so-called "crumple zone" is missing. In such an embodiment, the essential advantage of the approach proposed here can thus come to light, through which a simple possibility for detecting collisions with a high risk of injury can be realized.

Furthermore, in another embodiment, in the receiving step, the signal may be received by a sensor disposed in an area of the vehicle on the vehicle door, the area located at a location of the vehicle door that is transverse to the direction of travel at the height of the head , the thorax, the torso or the pelvis of an occupant seated on a vehicle seat of the vehicle. In the area of the thorax, torso, head or pelvis, the greatest risk of injury to an occupant is a side impact of an object on the vehicle. For this reason, it is particularly advantageous if the sensor is arranged at a position of the vehicle door, which is located transversely to the direction of travel at the level of the head, the torso or the pelvis, as in an installation of the sensor at this point also the largest sensor sensitivity the most vulnerable parts of the body can be reached.

In order to allow a different sensitivity of the sensor at particularly vulnerable places, in the step of receiving the signal can be received by a capacitive sensor having at least one electrode having a greater length than a width and / or having an angled shape. Such equipped electrodes of a capacitive sensor allow different sensitivities of the sensor in different detection ranges. In this way, different levels of sensor signals can be generated, depending on where in the vehicle via the sensor, the object hits exactly.

In another embodiment of the present invention, in the receiving step, the signal may be received in the form of a plurality of sub-signals from the capacitive sensor having at least one electrode comprising a plurality of sub-electrodes, wherein one sub-signal is provided per sub-electrode Further, a step of detecting a position of an occupant is provided on the vehicle seat and wherein in the step of releasing or triggering depending on the detected position of the occupant of one of a plurality of sub-signals is used as a signal to be evaluated. By using a sensor in which at least one electrode is subdivided into a plurality of sub-electrodes, an additional safety gain can be achieved by switching the signal evaluation of signals of the individual sub-electrodes. In particular, if at the same time the position of the occupant is detected on the vehicle seat, an active personal protection system can be realized in the different release or release signals for different personal protection means, such as side airbags, given when the occupant bends forward in a first scenario or, in a second scenario, sitting in a position where his back rests on the vehicle seat back.

It is particularly favorable if, furthermore, a step of obtaining a second sensor signal from a second capacitive sensor is provided, wherein the second sensor signal corresponds to a speed of a part of the vehicle in the direction of the second sensor, wherein the second sensor is arranged at another point in the vehicle is as the sensor, and wherein the step of releasing or triggering is further based on the further sensor signal. In such an embodiment, the release decision can be made on the basis of two sensor signals, for example, located at different heights above the roadway. In this way, a two-dimensional evaluation of the impact location can be realized in a simple manner, which enables a very precise location of the impact location of the object in the vehicle. In this way, a situation-specific triggering of the appropriate security means can be effected.

It is also particularly advantageous if a step of providing a structured part of the lateral vehicle door is provided, wherein the part of the vehicle door is structured in such a way that a measuring range of the part of the vehicle door which lies in the immediate measuring range of the sensor has a different deformation rigidity, as a damping area of the part of the vehicle door which is arranged at a predefined distance from the measuring area. Such a structured part of the lateral vehicle door allows a special deformation characteristic when an object hits this structured part. For example, a structure of the vehicle door provided with beads or other embossments may be stiffer than a structure of smooth sheet metal. The smooth sheet metal structure will then be more easily deformable than the structure with beads or other imprints. This leads to different behavior in the change of the distance between the door panel and the sensor, so that, depending on the impact of the object on the vehicle panel, also different speeds of intrusion result. This provides an additional way to easily and reliably detect the impact of an object in a zone with high risk of injury to a vehicle occupant.

• 1 ein Blockschaltbild einer Anordnung von Komponenten eines Personenschutzsystems, dass ein erstes Ausführungsbeispiel der vorliegenden Erfindung verwendet;
• 2 eine schematische Darstellung einer Position eines Fahrzeuginsassen relativ zu einer schematisch dargestellten Türe des Fahrzeugs (obere Teilfigur) und ein Diagramm eines Verletzungsrisikos eines Insassen in Abhängigkeit vom Kollisionspunkt (untere Teilfigur);
• 3 eine schematische Darstellung eines Einbauorts des Sensors in der Fahrzeugtüre im Bereich des höchsten Insassenrisikos (obere Teilfigur) und ein Diagramm einer entfernungsabhängigen Empfindlichkeit des Sensors in Bezug auf den Aufprallort (untere Teilfigur);
• 4 eine schematische Darstellung des Einbauorts des Sensors in einer Fahrzeugtür gemäß einem Ausführungsbeispiel der vorliegenden Erfindung;
• 5 eine beispielhafte Darstellung einer geometrischen Situation bei einer seitlichen Kollision eines Objektes in die Türe;
• 6 eine schematische Darstellung des Einbauorts des Sensors in einer Fahrzeugtür in Form eines inversen Einbaus gemäß einem weiteren Ausführungsbeispiel der vorliegenden Erfindung;
• 7 ein Ablaufdiagramm eines Ausführungsbeispiels der vorliegenden Erfindung als Verfahren.

The invention will be described by way of example with reference to the accompanying drawings. Show it:

• 1 a block diagram of an arrangement of components of a personal protection system that uses a first embodiment of the present invention;
• 2 a schematic representation of a position of a vehicle occupant relative to a schematically illustrated door of the vehicle (upper part of the figure) and a diagram of an injury risk of an occupant depending on the collision point (lower part of the figure);
• 3 a schematic representation of a location of the sensor in the vehicle door in the area of the highest occupant risk (upper part of the figure) and a diagram of a distance-dependent sensitivity of the sensor with respect to the impact location (lower part of the figure);
• 4 a schematic representation of the installation location of the sensor in a vehicle door according to an embodiment of the present invention;
• 5 an exemplary representation of a geometric situation in a lateral collision of an object in the door;
• 6 a schematic representation of the installation location of the sensor in a vehicle door in the form of an inverse installation according to another embodiment of the present invention;
• 7 a flowchart of an embodiment of the present invention as a method.

The same or similar elements may be indicated in the figures by the same or similar reference numerals, wherein a repeated description is omitted. Furthermore, the figures of the drawings, the description and the claims contain numerous features in combination. It is clear to a person skilled in the art that these features are also considered individually or that they can be combined to form further combinations not explicitly described here. Furthermore, in the following description, the invention may be explained using different dimensions and dimensions, wherein a mention of these dimensions and dimensions is not to be understood as limiting the invention to these dimensions and dimensions. Furthermore, method steps according to the invention can be repeated as well as carried out in a sequence other than that described. If an embodiment comprises a "and / or" link between a first feature and a second feature, this can be read so that the embodiment according to one embodiment, both the first feature and the second feature and according to another embodiment, either only the first Feature or only the second feature.

1 shows a block diagram of an arrangement of components of a personal protection system, which uses a first embodiment of the present invention. Here are in a vehicle 100 arranged a plurality of sensors, such as an acceleration sensor 110 and an ultrasonic sensor 120 that come with an evaluation unit 130 are connected. The acceleration sensor shown here 110 and the ultrasonic sensor 120 are as shown 1 in the front of the vehicle 100 housed, however, the sensors can 120 or 130 also in other places in the vehicle 100 be arranged. Alternatively or additionally, other sensors such as a pressure sensor or a structure-borne sound sensor in the vehicle 100 be installed, which also with the evaluation 130 can be connected. However, these sensors are in 1 not shown in detail.

Modern vehicle structures are designed so that the vehicle occupants are exposed during a frontal collision up to a high collision speed only a relatively low risk of injury. It is achieved on the one hand by the incorporation of special structures in the vehicle, which by deformation over a large amount of energy (crumple zones), due to a large safety distance to the structures to the front (eg instrument panel) as well as occupant protection such as seatbelt and airbag. To trigger this security or occupant protection means, the evaluation 130 for example, the received signals from the acceleration sensor 110 (as activation signal) and the ultrasonic sensor 120 (as a plausibility signal) and the personal safety device, such as a front airbag 140 or a belt tensioner 150 on a vehicle seat 160 activate if the signals have a value that is above a predefined threshold. In this way, a vehicle occupant 170 in an accident of the vehicle 100 be optimally protected with an enemy vehicle or other object.

In the case of a side impact, the external conditions are somewhat different: the space for accommodating deformable elements in the vehicle side is significantly lower than in the vehicle front. For this reason, intrusion of vehicle structures into the passenger compartment is to be expected even at lower speeds than in the case of vehicle front collisions in the case of side collisions. Similarly, at collision points near the occupant position, there is significantly less space available between the structure and the occupant than in a frontal collision. Accordingly, such collisions would lead to a higher risk of injury to the occupant. Conversely, at collision points farther from the occupant, the risk of injury is less. The above applies in particular to collisions with narrow objects such as trees, lampposts or pole objects such as those used in certification and consumer tests to prove occupant protection. Example of this is eg the US-American test FMVSS 214 ,

The above is particularly in the consideration of the 1 even clearer. In 1 It is very clear that there is a problem in protecting the occupant 170 then, if an enemy vehicle or other object is from a lateral direction 180 at the level of the occupant 170 because in this case the vehicle 100 has no or only a very small crumple zone. The enemy vehicle or object can thus quickly impact the occupants 170 reach and cause serious injuries there. In order to prevent such injuries, according to one embodiment of the present invention, a sensor 190 Preferably, a non-predictive capacitive sensor may be employed in a side door of the vehicle 100 is installed. From the signal of this sensor 190 For example, in conjunction with another signal such as a signal from the acceleration sensor 110 or the ultrasonic sensor 120 , then early by the evaluation unit 130 eg a side or head airbag 200 be triggered to the vehicle occupants 170 optimally protected. The exact arrangement and the signal acquisition of such a sensor 190 will be described in more detail below.

An alleged disadvantage of the capacitive sensor is the strong dependence of the sensor signal on the distance between sensor and impact location. However, this property is turned to the advantage by the approach presented here. An important aspect of the invention is the use of a Sensierungsprinzips, which has a strong sensitivity change over the distance to the impact location. The sensor is positioned so that the maximum sensitivity is exactly where the occupant is most susceptible to injury (i.e., in the area of the chest and / or head). However, the sensitivity of the sensor may be low at locations where the injury to the occupant is less life threatening (e.g., at the legs and / or feet). By further preferably using a non-prospective sensor, the environmental conditions around this sensor are very well known. In this way, the sensor sensitivity for the detection of an impact can be set very high, since in such a case disturbing environmental influences are conveniently shielded by a metal layer (i.e., the vehicle door panel).

This situation is schematic in 2 reproduced in more detail. 2 shows a schematic representation of the relationship between the position of the occupant and the risk of injury to the occupant in an impact of the object laterally on the vehicle. In an upper part diagram is the position of the occupant 170 on the vehicle seat 160 relative to a door shown schematically 210 of the vehicle 100 played. In a lower sub-diagram is the risk of injury 220 of the occupant 170 depending on the collision point (or impact location) 230 applied. As can be seen from the lower part of the diagram, there is the highest risk of injury in the area of the head, thorax, torso and pelvis. For the reasons mentioned above, the requirements for an occupant protection system for side collisions are significantly higher than for front collisions. Due to the proximity of the collision location to the occupant, for example, a side or head airbag should be fired significantly faster and earlier than a front airbag. On the other hand, if the impact point is further away from the occupant (ie more in the area of the legs / feet or the backrest of the vehicle seat 160 ), at the same collision speed the ignition of the Side retention means at a later time. Only at higher collision speed it may be useful here to ignite the side restraint or the airbag at the same time as in close-collisions.

Occupant protection devices according to the prior art only incompletely take into account this sensible variation of the triggering requirements at the collision location in relation to the occupant. It is at most a collision laterally front (at the level of the front occupants) or laterally behind (at the height of the rear passengers) distinguished. This is due to the characteristics of the previously used sensor. Typically, such sensors are used whose sensitivity depends only slightly on the distance to the impact location. Thus, e.g. Pressure sensors, which are installed in the side vehicle door, a nearly uniform sensitivity over the entire door area. Conventionally mounted acceleration sensors exhibit a similar characteristic due to the low attenuation of acceleration signals. The downstream data processing is therefore no longer able to localize the impact site more precisely.

By contrast, the approach proposed here implicitly takes into account the information of the point of impact. The release behavior of the restraint system is thus better adapted to the actual risk of injury to the occupant. As a result, on the one hand, unnecessary trips can be suppressed (resulting in a desirable reduction in repair costs) and, on the other hand, the injury values of passengers can be advantageously reduced. This is achieved, for example, by the choice of a sensing principle or a corresponding preparation of the installation location, which leads to the signal obtained having a distance dependence to the impact location, ie the sensitivity of the sensor decreases with increasing distance of the collision point from the sensor installation location. As a very favorable embodiment is doing the Sensoreinbauort 240 chosen so that the range of maximum sensor sensitivity coincides with the area of highest occupant injury risk. Such a connection is in 3 shown in more detail, wherein in the lower part of a graph graph 250 is entered, indicating the sensitivity of the sensor 190 in relation to the place of impact 230 reproduces. Since the highest risk of injury exists especially in the area of the thorax of the occupant, the sensor should 190 be installed in an area of the side door, which is in lateral (ie in the direction transverse to the direction of travel of the vehicle) height of the thorax. Also, an arrangement position at the height of the head can be provided if a special head protection is to be realized. This Sensoreinbauort can be chosen such that the actual mounting position in a tolerance range of, for example, 10 cm to the in 3 shown position 240 lies. This advantageously offers the possibility of obtaining a good and stable attachment in the vehicle door with negligible sensitivity limitation. Such a good fastening possibility in the vehicle door can be, for example, constructional, if the vehicle door structure is reinforced at certain points by struts to optimize rigidity and the sensor can be fastened securely and securely to such struts, but these reinforcing struts are not exactly in one position. as they are in 3 is shown. In 3 In this case, a proposed sensor installation location in the area of the highest occupant risk is shown in the upper partial diagram. The lower part of the figure shows the distance-dependent sensitivity of the sensor 190 depending on the place of impact.

The approach presented here offers several advantages. First, a simplification of the data evaluation and thus a simpler triggering algorithm can be used. Furthermore, involvement of the risk of injury of the occupant in the triggering process can take place, as a result of which a situation better adapted activation of restraint means becomes feasible. Furthermore, a Sensierungsprinzip can be used, which can detect very quickly crash situations. In this case, a capacitive sensor is favorably used; but also other sensing possibilities, such as a RADAR-based distance or velocity-providing sensor are in principle applicable, provided that they have the properties described. In addition, the approach presented here can be combined excellently with security systems already installed as standard, so that the effort required to introduce an additional security concept is negligible. Furthermore, in addition to the data used in the "standard ECall" (such as GPS positioning, crash type and direction), data such as the determined impact location, information on whether the occupants are strapped or not, a multiple / single-crash scenario, an airspeed, etc. used to ultimately transmit the risk of injury immediately.

The following is now with the help of the presentation 4 an example of the implementation of a specific sensor given the properties described. 4 shows a schematic representation of an installation location of the sensor 190 in a vehicle door 210 in cross-sectional view through a vehicle door. The sensor 190 can be at a sensor installation position as shown 3 be installed. A capacitive sensor becomes an example 190 chosen, which on a support structure 400 for the sensor 190 in the interior of the door 210 ie between the door interior trim 410 and the outside door panel 420 is installed. The carrying structure 400 can be a spar of the vehicle door 210 be. The measured variable is the distance 430 or more specifically the distance change in time (ie, the rate of intrusion) of the door outer panel 420 to the sensor 190 , In case of a collision with an object in this area, the collision will cause the door outer panel 420 pressed inwards, so the distance 430 between sensor 190 and outside door panel 420 changes.

During a collision, this measurement principle will now have the following effects: If a collision K1 At the level of the occupant (ie in the direct measuring range of the sensor), the signal obtained will be of high amplitude. Over a simple predetermined threshold can now trigger a algorithm, for example in the evaluation 130 (eg the airbag control unit) decide whether the signal amplitude or the amplitude of a signal derived from the signal reaches a certain constant threshold S. If this is the case, the occupant protection means, such as a side or head airbag is activated. In comparison, there will be a collision K2 at the same collision speed, but at another impact point further away from the sensor installation site 240 generate a signal of lower amplitude. If necessary, this signal amplitude will no longer be large enough to exceed the constant threshold S. Accordingly, no retention means will be activated or released. This is exactly the desired behavior: because the danger to the occupant in the collision K1 higher, it needs a restraint. In a collision K2 the collision continues further away; the occupant is less at risk and no means of retention must be activated.

If there is a collision K3 at a location corresponding to the collision K2 takes place, but this time with a much higher collision speed, the signal amplitude (which also depends on the collision speed) will be higher than in the collision K2 , Accordingly, the sensor signal will also have a larger amplitude and be able to exceed the threshold S. This in turn means that the retention means are activated. This is exactly the intention: Although the collision takes place somewhat further away from the occupant, this positive effect on the occupant's risk of injury is compensated for by the increased impact speed. In this example, it has been shown how with a sensor that has a distance-dependent sensitivity, an appropriate risk of injury to the occupants (which is often quantified by the MAIS value, MAIS = Maximum Abbreviated Injury Scale) can be achieved without that a complicated and special triggering logic needs to be used.

In a simple approximation, the dependence of the sensitivity of the sensor on the distance from the collision point can be determined using the illustration 5 be illustrated. It is in 5 an intrusion of the outer door skin, which originated at the collision location xc (referring to a left door frame 500 ), but also in other places to a movement of the outer door skin 420 will lead. The outer door skin 420 is typically a relatively thin sheet, which provides little force to a penetrating object. In a collision, the outer door skin 420 Therefore, behave almost like a resilient membrane, which on the outer sides (ie the door frame 500 ) is firmly clamped. This means that when in place xc (relative to the left door frame 500 ) the impact of the object takes place, is at a time t1 of the door panel 420 to be indented by a certain penetration depth dc. At the sensor location xs (again referring to the left door frame 500 ), the penetration depth ds becomes as shown 5 be lower. It is easy to estimate. After the set of rays the relation xc / xs = dc / ds applies. It follows for ds: ds = 1 / xc * dc * xs. This means that the penetration depth ds at the location of the sensor 190 given dc is inversely proportional to the distance xc. But now the penetration depth ds is exactly the measurable distance change between the outer door skin 420 and sensor 190 at the sensor installation location 240 , Thus, the distance-dependent sensitivity of the sensor follows a 1 / xc law. The distance xs between the left door frame 500 and the sensor installation location 240 is a fitting-specific and thus known size. A mounted capacitive sensor 190 So has all the required properties. An extension of this calculation to two dimensions (not only the door width but also their height) is correspondingly easy to perform.

Furthermore, there are various ways to improve the approach proposed above. A first possibility for improvement can be seen in a targeted attachment of stiffeners in the door, so that this way the distance-dependent sensitivity of the sensor can be modified. For certain zones, which are smooth or structured, for example, higher or lower sensitivities can then be realized in a targeted manner. Thus, in addition to the distance-dependent sensitivity, a direction-dependent sensitivity can also be specified (also known as pulse shaping).

Likewise, in the case of the capacitive sensor, the shape of the capacitor plate (s) can realize certain sensitivity patterns. For example, a capacitor plate in an elongated shape in the direction predetermined by the longitudinal axis be more sensitive than in the direction predetermined by the short transverse axis. There are also L-shaped or other, curved forms can be used.

It is also possible by dynamic shaping (eg by moving different capacitor plates or, if the capacitor is realized by interconnecting individual small capacitor plates, by targeted switching on and off of the capacitor plates) to realize a direction and distance-dependent sensitivity directly the occupant position in the vehicle For example, if the occupant bends forward, the sensor will shift its sensitivity maxima forward. If he raises his legs, the area of the lower part of the door is switched less sensitive. In order to achieve this, additional information about the position of the occupant should be available, e.g. from an IBolt system or from another interior sensing system. Switching or increasing the sensitivity of a moving occupant can be achieved by using a sensor signal from the sub-electrode closest to the occupant.

In practice, the risk of injury can first be stated on the basis of the MAIS values as a function of the place of impact. Data from accident research as well as data from crash simulations can be used as a source for this. According to the spatial distribution of these values then the most favorable installation location for the sensor can be selected. Accordingly, the distance and direction-dependent sensitivity of the sensor can then be adjusted so that it corresponds to the risk of injury to the occupant according to one of the methods specified above.

The system is not necessarily limited to the vehicle side in its application. It is also conceivable to apply it in the vehicle front or in the rear. It can also be used for pedestrian protection.

The system is not necessarily limited to the application of a capacitive sensor. Any other sensor principle capable of providing range dependent signals or velocity signals, e.g. RADAR sensors are also possible. Capacitive sensors, however, are well-researched and provide accurate and quick-to-evaluate results. Furthermore, capacitive sensors are available at low cost. Since a capacitive sensor is linked to the injury severity / risk (often specified in MAIS) in the example given, one can speak of a capacitive MAIS sensor.

In the example described above, the sensor is on the support structure 400 the door 210 attaches and recognizes the intruding door outer panel 420 during a side collision. Another conceivable variant would be to make the inverse installation, the in 6 as a schematic representation of another installation location of the sensor 190 in a vehicle door 210 is shown. The capacitive sensor 190 becomes the door outer panel from the inside 420 mounted and senses the distance to the support structure 400 , In a side crash in combination with an intrusion, the sensing distance decreases as well as in 4 ,

7 shows a flowchart of an embodiment of the present invention as a method 700 for controlling a personal safety device 200 of a vehicle, the method 700 a step of receiving 710 a sensor signal from a capacitive sensor, wherein the sensor signal corresponds to a speed of a part of the vehicle in the direction of the sensor. Further, the method has 700 a step of releasing 720 or triggering the personal security device 200 when the sensor signal represents a speed greater than a predetermined threshold.

Claims (9)

A method (700) for driving a personal safety device (200) of a vehicle (100), the method (700) comprising the following steps: - receiving (710) a sensor signal from a capacitive sensor (190) the sensor signal corresponds to a speed of a part (420) of the vehicle (100) in the direction of the sensor (190); and - enabling (720) or triggering the personal security means (200) when the sensor signal represents a speed greater than a predetermined threshold; characterized in that there is further provided a step of obtaining a second sensor signal from a second capacitive sensor, the further sensor signal corresponding to a speed of one part (420) of the vehicle (100) towards the second sensor, the second sensor being at another Position in the vehicle is arranged as the sensor, and wherein the step of releasing (720) or triggering further takes place on the basis of the second sensor signal. Method (700) according to Claim 1 characterized in that in the step of receiving (710) a sensor signal is received which is arranged in a lateral vehicle door (210), wherein the sensor signal of a speed of a part (420) of the vehicle door (210) in the direction of the sensor (190) equivalent. Method (700) according to one of the preceding claims, characterized in that in the step of receiving (710) the signal is received by a sensor (190) which is arranged in a region of the vehicle (100) on the vehicle door (210), wherein the area is located at a location of the vehicle door (210) that is transverse to the direction of travel at the level of the head, torso or pelvis of an occupant (170) seated on a vehicle seat (160) of the vehicle (100). Method (700) according to one of the preceding claims, characterized in that in the step of receiving (710) the signal is received by a capacitive sensor (190) having at least one electrode having a length greater than a width and / or which has an angled shape. Method (700) according to one of the preceding claims, characterized in that in the step of receiving (710) the signal is received in the form of a plurality of sub-signals from the capacitive sensor (190) having at least one electrode comprising a plurality of Sub-electrode, wherein a sub-signal is provided per sub-electrode, further comprising a step of detecting a position of an occupant on the vehicle seat (160) and wherein in the step of releasing (720) or triggering depending on the detected position of the occupant (170 ) one of a plurality of sub-signals is used as a signal to be evaluated. Method (700) according to one of the preceding claims, characterized in that there is further provided a step of providing a structure of the part (420) of the side vehicle door (210), wherein the part (420) of the vehicle door (210) is structured in such a way in that a measuring range of the part (420) of the vehicle door (210) which lies in the measuring range of the sensor (190) has a different deformation stiffness than a damping area of the part (420) of the vehicle door (210) which is at a predefined distance from the measuring range is arranged. A controller (130) configured to perform the steps of a method (700) according to any one of Claims 1 to 6 perform. Computer program product with program code, which is stored on a machine-readable carrier, for carrying out and / or driving the steps of the method (700) according to one of Claims 1 to 6 when the program is executed on a controller (130) or a data processing system. A unit for triggering or releasing a personal security device (200) of a vehicle (100), the unit having the following features: a capacitive sensor (190) configured to sense a speed at which a portion of the vehicle (100) is moving toward the sensor (190), the sensor (190) being further adapted to receive one of provide the detected speed corresponding signal; a second capacitive sensor is provided, which is designed to detect a speed with which a part of the vehicle (100) moves towards the second sensor, wherein the second sensor (190) is further configured to detect one of the detected Speed corresponding to provide another signal, wherein the further signal corresponds to a speed of a part (420) of the vehicle (100) in the direction of the second sensor, wherein the second sensor is disposed at a different location in the vehicle than the first sensor; and - An evaluation unit (130) for receiving the signal of the sensor (190), wherein the evaluation unit (130) is adapted to trigger a personal safety device (200) of the vehicle (100) or release when the received signal represents a speed, the greater is as a predefined threshold value, wherein the step of enabling (720) or tripping is further performed on the basis of the second sensor signal.

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