DE102008044211A1 - Sensor for providing signal to detect impact of object on vehicle, has holding element for attachment of sensor on vehicle surface, where impact detecting signal is provided by using two connection contacts - Google Patents

Abstract

The sensor (100a,100b,100c,100d) has a holding element for attachment of the sensor on a vehicle surface. The holding element has a connection contact for contacting the vehicle surface or an electrically conductive layer on the vehicle surface. An electrically conductive shielding layer is arranged opposite the vehicle surface or the electrically conductive layer in an area of the vehicle surface in an electrically insulated manner. Impact detecting signals are provided by using two connection contacts. Independent claims are included for the following: (1) a method for triggering a restraining device of a vehicle; (2) a computer program for executing a restraining device triggering method; and (3) a control unit.

Description

State of the art

The The present invention relates to a sensor for providing a signal for detecting an impact of an object on a A vehicle according to claim 1 and a method for triggering a restraining means of a vehicle according to claim 4th

• – ein Triggersignal mit höherer Auslöseschwelle zur Auslösung des Rückhaltemittels, und
• – ein Plausibilitätssignal mit niedrigerer Auslöseschwelle zur Überwachung des Triggersignals und zur Vermeidung von fehlerhaften Auslösungen.

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

• A trigger signal with a higher triggering threshold for triggering the restraining means, and
• - A lower tripping threshold plausibility signal to monitor the trigger signal and prevent erroneous tripping.

• – einem Upfrontsensor (= Beschleunigungssensor im Frontbereich des Fahrzeugs),
• – einem PAS (PAS = peripheral acceleration sensor = peripherer Beschleunigungssensor in der Fahrzeugseite),
• – einem PPS (PPS = peripheral pressure sensor = peripherer Drucksensor in der Fahrzeugseite)
• – einem Airbag-Steuergerät (insbesondere Beschleunigungssensoren hierin).

These two signals usually come from different crash sensors such as:

• An upfront sensor (= acceleration sensor in the front area of the vehicle),
• A PAS (Peripheral Acceleration Sensor in the vehicle side),
• A PPS (PPS = peripheral pressure sensor in the vehicle side)
• An airbag control unit (in particular acceleration sensors herein).

These Trigger and plausibility signals are necessary for false tripping excluded; a fixed assignment which sensor signal is used as a trigger or as a plausibility signal, there is not any.

Known is also the use of environment sensors (eg radar sensors), about the tripping behavior of the restraint systems to improve information already determined before the crash.

Capacitive distance sensors (eg from the GB2404443A ), which monitor the exterior of vehicles to detect an imminent collision.

• – Erstens der neue FMVSS 214 Test, der auch ”oblique pole test” genannt wird. Dabei wird das Fahrzeug nicht, wie üblich im 90°-, sondern im 75°-Winkel mit einer Geschwindigkeit von 32 km/h auf einen Pfahl geführt. Dabei wird das Fahrzeug so positioniert, dass das Pfahl direkt auf Kopfhöhe des Fahrers einschlagen soll. Da sich die stabilisierende B-Säule weit entfernt vom erwarteten Aufprallort befindet, ist eine hohe Intrusion und somit ein hohes Verletzungsrisiko zu erwarten.
• – Zweitens der IIHS-Seitenaufprall-Test: Es handelt sich hier um einen Barrierentest, wobei die Barrierenstruktur der eines SUV-Fahrzeuges (SUV = sport utility vehicle = Geländewagen) entspricht. Gegenüber einem üblichen Seitencrash mit Barriere werden beim IIHS-Test eine höhere Masse und eine höhere Barriere mit mehr Bodenfreiheit verwendet. Dies bedeutet, dass die Intrusion über dem Schweller in das zu testende Fahrzeug einschlägt. Der sehr steife und dadurch stabilisierende Schweller hat hier nur sehr wenig positiven Einfluss beim Unfallgeschehen. Dies kann zu einem erhöhten Verletzungsrisiko für die Insassen des zu testenden Fahrzeugs führen.

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

• - First, the new FMVSS 214 test, also called "oblique pole test". The vehicle is not guided onto a pole at a speed of 32 km / h, as usual at a 90 ° angle, but at a 75 ° angle. In doing so, the vehicle is positioned so that the pile should strike directly at the driver's head height. Since the stabilizing B-pillar is far away from the expected impact site, a high level of intrusion and thus a high risk of injury is to be expected.
• - Second, the IIHS Side Impact Test: This is a barrier test where the barrier structure corresponds to that of a SUV (SUV = SUV) vehicle. Compared to a standard side impact barrier, the IIHS test uses a higher mass and a higher barrier with more ground clearance. This means that the intrusion over the sill hits the vehicle under test. The very stiff and thus stabilizing sill has very little positive influence on the accident. This can lead to an increased risk of injury to the occupants of the vehicle under test.

• 1. Das Triggersignal wird von einem peripheren Sensor und das Plausibilitätssignal direkt im Airbag-Steuergerät ermittelt.
• 2. Das Triggersignal wird von einem peripheren Sensor und das Plausibilitätssignal wird von einem anderen peripheren Sensor bereitgestellt.

In the current state of the art, there are two widely used variants to avoid a false triggering of the restraining means (such as an airbag):

• 1. The trigger signal is determined by a peripheral sensor and the plausibility signal directly in the airbag control unit.
• 2. The trigger signal is provided by a peripheral sensor and the plausibility signal is provided by another peripheral sensor.

at Some vehicles already have this state of the art today possible, the legal requirements regarding page crashes fulfill. However, there are still enough vehicles the u. a. the new crash tests (FMVSS 214 new and IIHS) deficient or not at all. The reason is often one collision detected too late and, since the speed of intrusion is very high, there is a risk that the side airbag (thorax airbag) is not properly position between the occupant and the vehicle structure can.

The Variant 1 mentioned above is the most cost-effective in the prior art. There will only be one peripheral sensor in each side of the vehicle built-in. The disadvantage of this variant must - under certain circumstances - the Tripping delay can be seen. The airbag control unit is usually in the middle of the vehicle (for example in the tunnel) and is thus quite far from the impact site. A sensor to provide the plausibility signal, usually is provided in this variant in the airbag control unit, can thus only "late" the collision recognize and output the plausibility signal.

The above variant 2 made possible light a faster triggering of the safety or restraint systems as both affected peripheral sensors are located directly at the impact site. However, this variant is somewhat more expensive, since at least two peripheral sensors must be installed in each side of the vehicle.

Disclosure of the invention

• – ein Halteelement zur Befestigung des Sensors auf einer Fahrzeugoberfläche, wobei das Halteelement einen ersten Anschlusskontakt zur Kontaktie rung der Fahrzeugoberfläche oder einer elektrisch leitfähigen Lage im Bereich der Fahrzeugoberfläche umfasst;
• – eine elektrisch leitfähige Abschirmlage, die gegenüber der Fahrzeugoberfläche oder einer elektrisch leitfähigen Lage im Bereich der Fahrzeugoberfläche elektrisch isoliert angeordnet ist; und
• – einer (oder mehrere) Elektrode(n), die auf einer dem Halteelement abgewandten Seite der Abschirmlage angeordnet ist und die über den zweiten Anschlusskontakt elektrisch kontaktierbar ist und von der Abschirmlage elektrisch isoliert ist.

The present invention provides a sensor for providing a signal for detecting an impact of an object on a vehicle, the signal being providable using first and second terminal contacts of the sensor, and wherein the sensor comprises the following features:

• - A holding element for mounting the sensor on a vehicle surface, wherein the holding element comprises a first terminal contact for Kontaktie tion of the vehicle surface or an electrically conductive layer in the region of the vehicle surface;
• - An electrically conductive Abschirmlage, which is arranged electrically isolated from the vehicle surface or an electrically conductive layer in the region of the vehicle surface; and
• - One (or more) electrode (s), which is arranged on a side facing away from the holding element of the shielding and which is electrically contacted via the second terminal contact and is electrically isolated from the shielding.

• – Bereitstellen eines ersten Sensorsignals, das eine Änderung einer Kapazität, einer Induktivität oder eines Widerstandes eines am Kraftfahrzeug angeordneten Sensors repräsentiert;
• – Bereitstellen eines zweiten Sensorsignals, das einen Kurzschluss von zwei Elektroden und/oder einer Elektrode und einer elektrisch leitfähigen Abschirmlage zwischen zwei Elektroden des am Kraftfahrzeug angeordneten Sensors repräsentiert; und
• – Auslösen des Rückhaltemittels des Kraftfahrzeugs auf der Basis des ersten und zweiten Sensorsignals oder auf der Basis eines Sensorsignals eines weiteren Sensors in Kombination mit dem ersten und/oder zweiten Sensorsignal.

Furthermore, the present invention provides a method for triggering a restraining means of a motor vehicle, the method comprising the following steps:

• - Providing a first sensor signal representing a change in a capacitance, an inductance or a resistance of a sensor arranged on the motor vehicle;
• - Providing a second sensor signal representing a short circuit of two electrodes and / or an electrode and an electrically conductive Abschirmlage between two electrodes of the sensor arranged on the motor vehicle; and
• Triggering the restraining means of the motor vehicle on the basis of the first and second sensor signals or on the basis of a sensor signal of a further sensor in combination with the first and / or second sensor signal.

The The present invention further provides a controller that for carrying out the method described above is trained. Under a control unit can present an electrical device to be understood, the sensor signals processed and in response outputs control signals. The Control unit can have an interface which and / or may be formed by software. In a hardware training can the interfaces, for example, part of a so-called system ASICs be, which includes a variety of functions of the controller. However, it is also possible that the interfaces have their own, integrated Circuits are or at least partially discrete components consist. In a software training The interfaces can be software modules, for example on a microcontroller in addition to other software modules available are.

From Advantage is also a computer program product with program code, the on a machine-readable medium such as a semiconductor memory, stored in a hard disk memory or an optical memory is and to carry out the method according to one of used in the above-described embodiments, if the program is running on a controller becomes.

The invention is based on the recognition that triggering of a restraining means of a motor vehicle can be triggered or monitored by signals originating from a single sensor, provided that this sensor can use two different measuring principles. For this purpose, a special sensor and a special evaluation of the received signals from the sensor are to be used. On the one hand, the sensor should output a signal upon a change in capacitance, inductance or resistance in the sensor area (in particular due to an approaching object or vehicle) and, on the other hand, output a second signal if a short circuit exists between the two connection contacts of the respective sensor or between one Terminal contact and the electrically conductive shielding layer is detected. In this case, the electrically conductive shielding layer can ensure a focussing of the sensing of the capacitance change away from the vehicle, so that, in particular, large masses of electrically conductive material, which arrive at the vehicle, are considered in the provision of the first signal. In this way, this dangerous approach can be detected by the capacitance, inductance or resistance change already before a collision of the foreign vehicle in the vehicle with the sensor presented here. By the impact of the other vehicle on the vehicle under consideration, which deforms the electrodes of the sensor so that a short circuit between the terminals of the sensor (via eclectically conductive shielding) arises, the second signal (in an evaluation of this short-circuit behavior) is generated. Since the first and second signals are received from the one sensor in different physical ways, the first and second signals from the considered sensor (as the sole sensor) in a trigger unit for triggering the return be used without loss of security. The first or second signal can be used in each case as a trigger or plausibility signal; it is important to recognize in two different ways that there is a situation to trigger a restraint.

The present invention offers the advantage that on the one hand a single Sensor for providing the plausibility signal and the Trigger signal is usable. This means fewer sensors for the safe and error-free determination of a restraining agent triggering case are required, resulting in a cost advantage. on the other hand can also with a constant number of held sensors a safety benefit is obtained because of the use of the presented here sensor (or the evaluation) an additional Signal for determining the retention agent triggering case is present and can be used.

Cheap it is when the holding element is an electrically conductive Position includes, in the fastened state on the vehicle surface is arranged. This offers the advantage that when applying the Sensor does not damage the paint finish of the vehicle surface or on the other hand no hole for the implementation the connection contacts of the sensor is required. Rather, it can by the simple provision of an electrically conductive layer (such as a film) another electrode for provided the capacitance or short circuit measurement become.

In According to a further embodiment of the invention, the sensor an evaluation unit, with the first and second terminal contact connected and which is designed to work at a capacity, Induction and / or resistance change between the first and second terminal contact to output a signal of the first kind and at a short circuit between the shielding layer and / or the first and / or second terminal contact to output a signal of the second kind. This allows the evaluation of the physical states directly done at the location of the sensor, so that the falsification of Measured values on supply lines to a central evaluation unit can be largely avoided.

at an embodiment of the invention as a method particularly favorable in the step of triggering the first or second sensor signal as a plausibility signal and the other of the first or second sensor signal or the other Sensor signal as trigger signal for triggering of the restraining agent. This allows the Triggering of the retaining means cost by the signals are from a single sensor, at the same time It can be ensured that adequate validation and Plausibility of the occurring signals is possible which leads to a fault-free release of the restraint means.

Around a release of the restraint means in particular then make, if in fact a foreign vehicle at high speed approaches the vehicle in which the sensor described above can, in the step of providing the first sensor signal is then provided when the change capacitance, inductance or resistance greater than a predefined change value is. For example, the first sensor signal may then be provided if the change value is a multiple of the original one (Normal) value. For example, if a slow Approaching a metallic object to the sensor occurs (such as touching the sensor by a shopping cart a supermarket parking lot), is the recorded change value for the capacity, the inductance or the Resistance not very high, so a deployment of the first Signal and thus a release of the restraining means can be prevented.

Further can in a further embodiment of the invention in Step of providing the second sensor signal on the base a detected change in resistance and / or capacitance between two electrodes and / or one electrode and one electrically conductive shielding between two electrodes. This offers the advantage of being a very fast and easy measurement an occurred short circuit is possible, so that an elaborate and time-consuming processing of accordingly measured physical quantities are not required is.

Around a fast and error-free evaluation of the sensor states To enable the steps of providing of the first and second sensor signals under by evaluating A voltage or a current take place between or on Terminal contacts detected a sensor described above become. This offers the advantage of using fixed predefined ones Values for the evaluation voltage and the evaluation current already slight changes Detect in the sensor area of the above proposed sensor and thus a quick evaluation and a quick meeting to enable a triggering decision.

The The invention will be described below with reference to the accompanying drawings exemplified in more detail. Show it:

1 a block diagram of an exemplary arrangement of sensors in a vehicle which provide signals to a controller, so that the controller can activate a person-retaining means in response to the signals supplied;

2 a representation of an embodiment of the sensor according to the invention in the sensing of an incoming object from an impact;

3 a representation of an embodiment of the sensor according to the invention in the sensing of an incoming object during an impact on the vehicle;

4 a pictorial representation of a mounting option of an embodiment of the sensor according to the invention in a vehicle;

5 a further pictorial representation of a mounting option of an embodiment of the sensor according to the invention in the vehicle;

6 a schematic representation of an example linking possibility of signals of an embodiment of the sensor according to the invention for triggering the restraint means;

7 a schematic representation of another exemplary possibility of linking signals of an embodiment of the sensor according to the invention for triggering the restraint means; and

8th a flowchart of an embodiment of the present invention as a method.

Same or similar elements can be found in the following Figures provided by the same or similar reference numerals be. Further included in the figures of the drawings, their description and the claims numerous features in combination. a It is clear to a person skilled in the art that these features are also considered individually or they become further combinations not explicitly described here can be summarized. Following dimensions and dimensions are for illustrative purposes only the invention and are not to be understood that the Invention limited to these dimensions and dimensions is.

The 1 shows a block diagram of an exemplary arrangement of sensors 100 in one (for example in the direction of travel 105 aligned) vehicle 110 that a control unit 120 Deliver signals so that the control unit 120 in response to the signals at least one person-retaining means 130 can activate. The sensors 100 can be configured differently; For example, a sensor 100a a capacitive sensor, which can detect a change in the capacitance in the measuring range and a change in the capacity (for example, by an incoming vehicle) a corresponding signal to the control unit 120 outputs. Another sensor 100b For example, it may be a structure-borne sound sensor that impacts the vehicle in the event of a collision with another vehicle 110 Detects and in response to the detected shock also a signal to the controller 120 outputs. However, the use of sensors can be particularly favorable 100c and 100d be, which are constructed according to the following explanations. These sensors 100c and 100d can be beneficial in the rear and / or side area of the vehicle 110 be installed and increase the safety especially in this area of the vehicle by the double security functionality described in more detail below. However, the structure of the sensors described here by way of example is 100c respectively. 100d not on the rear part of the vehicle 110 limited, as one skilled in the art will easily recognize.

The sensors 100a -D deliver signals to the controller 120 which is at least one retention means 130a respectively. 130b can trigger. The retention means 130a may be, for example, a (driver) airbag or a belt tensioner, while the other retaining means 130b a passenger airbag, a belt tensioner or other safety means may be for occupant protection. The retention means 130a and 130b may also be safety means for the occupants who are seated in the direction of travel behind the B-pillar. As will be described in more detail below, the sensors presented here by way of example may be used 100c and 100d also several mutually different signals to the controller 120 submit the decision on the triggering of one of the retention means 130a respectively. 130b also alone on the basis of signals from one of the sensors 100c respectively. 100d can meet.

As already mentioned above, the invention presented here proposes an innovation with respect to the provision and / or evaluation of sensor signals. The sensors that can be used for this purpose should therefore be presented in more detail first. The sensors usable for the invention 100c respectively. 100d can detect in a first functionality detection of an object based on a change of an electric or magnetic field or a resistance change between two terminal contacts. In essence, the first functionality is thus based on the functional principle of a capacitive (or inductive) sensor, the further description of the Invention should be based on a capacitive sensor, without sacrificing the other embodiments of the invention thereby. From a current perspective, this capacitive sensor in the prior art provides only a single signal, namely a capacitance or a signal that signals a change in capacitance. So far, therefore, to ensure a fault-free release of the restraint means, a further sensor should be present in order not to violate the trigger and plausibility signal rule of the non-interdependent signals for triggering the restraint means.

With the concept presented in this invention, it is possible with a capacitive sensor in addition to the capacitance signal to issue a (for example, binary) contact signal, as will be explained further below. Based on the already mentioned capacitive sensor 100c or 100d On the vehicle side, a new usage concept is presented, in which this capacitive sensor outputs additional information for the triggering decision.

A "capacitive" sensor 100c or 100d According to an embodiment of the present invention, both the above-mentioned Crash Detection Variant 1 (the trigger signal is provided by a peripheral sensor, the plausibility signal provided by the controller) and the aforementioned Variant 2 (both the trigger signal and the plausibility signal supplied by peripheral sensors). In the variant 2, however, in contrast to the prior art, both signals can be supplied from a single sensor according to a subsequent embodiment be described. This can either lead to cost reduction with consistent performance; However, a possible increase in performance (ie a faster and safer sensing) with constant costs is conceivable.

One The aim of this invention can thus be seen that the Sensor costs can be lowered while the Performance and triggering safety can be increased can, in which an additional Sensierungspfad or a Another usage concept of sensor signals is used.

The structure of a sensor according to an embodiment of the invention is for the sensor 100c described in more detail below, but the corresponding statements also analog for the sensor 100d or other sensors of the vehicle 110 apply the inventive approach presented here.

The here proposed "capacitive" sensor 100c (or 100d ) is according to the representation of the 2 and 3 (when attached to the vehicle 110 ) as follows: The outer panel 200 for example, in the area of one of the doors 210 of the vehicle 110 forms one of the electrodes. Alternatively, a thin layer of an electrically conductive layer on the paint of a vehicle can also form the first electrode. The second electrode 220 (also called measuring electrode) is on a vehicle interior 230 opposite side of the sensor (ie in the mounted state on the vehicle completely outside) attached. The sensor 100 can by a holding element 240 be attached to the door panel, which includes, for example, an adhesive element or a screw connection. At least the retaining element should 240 electrically insulating between an electrically conductive active screen 250 and the first electrode 200 (Also called reference electrode) may be introduced to a capacitance measurement or a capacitance change measurement between the two electrodes 200 and 220 to enable. Furthermore, the active screen 250 Conveniently with an evaluation unit or (with the control unit 120 if the evaluation unit in the control unit 120 arranged) connected to the capacitance between the two electrodes 200 and 220 to dissolve. This active screen 250 can be made of metal or a conductive material. Further, also the first electrode 200 via the first terminal A and the second electrode 220 via the two th connection contact B with the evaluation unit (or the control unit 120 ) connected to a signal evaluation of the signals of the sensor 100c to enable. Purpose of the arrangement described above is the disturbance capacity of a laterally arriving collision object 260 to measure alone.

The 4 and 5 show pictorial representations of a prototype of an embodiment of the invention as a "capacitive" sensor whose elements under a (here folded up) trim strip 400 at a vehicle door 210 are attached by way of example.

The operation of the approach proposed here can be at the hand of 2 and 3 describe as follows:
In a first step, a collision object approaches 260 (eg a foreign vehicle) to the door 210 of the vehicle 110 with the sensor presented here 100c or the implemented newly proposed evaluation strategy of the signals of a capacitive sensor. Such a vehicle incorporating the invention proposed herein will be referred to in the further description for convenience as an "ego vehicle". At a certain range, the capacitive sensor detects 100c this object 260 ,

In a second step, the approaching foreign vehicle approaches 260 continue the ego vehicle. The distance then decreases and the measured capacity between the first and third-party vehicle changes. The capacity gradient is due to the high speed of the foreign vehicle 260 very large and it is, for example, a plausibility signal (or trigger signal) to the evaluation or the (airbag) control unit 120 communicated. At this time, however, no collision has yet taken place, but only one of the triggering signals (ie the triggering signal or the plausibility signal) is present at the control unit 120 (or an evaluation unit in spatial proximity of the sensor 110c or in the sensor 110c itself). Thus, it does not yet come to the triggering decision for the release of the restraint means such as the airbag.

It should be noted that also the approach of a foreign vehicle can be measured complex. Not only does the capacity need to be evaluated (which is the main part of the sensor described above), but an inductance and / or resistance may also be used as a signal to bring the other vehicle closer 260 to the ego vehicle 110 to recognize. It is particularly important that a measurement of the approach of the foreign vehicle 260 before the actual collision on the basis of a measurement between the other vehicle 260 and the ego vehicle 110 done without contact between the two vehicles. This causes such a first signal to be obtained in a different physical manner than a signal generated when the foreign vehicle impacts 260 into the ego vehicle 110 by evaluating short circuits on the capacitive sensor 100c is determined.

In a third step, a collision occurs in which the other vehicle collides with the ego vehicle and the electrode 220 on the active screen 250 press and this in turn on the vehicle panel 200 (as the first electrode 200 ) is pressed. This is the time when the approach proposed here makes itself felt and shows its advantages. The capacitive sensor 100c is specially designed in its original condition so that there is no contact between the electrodes 200 and 220 and / or the active screen 250 prevails. So if - by the collision - a contact between two of the 3 elements sets, this can also be used. The approach presented here thus uses a kind of "short circuit detection" to provide the second signal.

With a (unwanted) contact of metallic elements with the sensor, therefore, changes of different physical quantities result. Two of them can be used to detect the contact - and thus the collision:
On the one hand, the resistance between the elements (electrodes or the active screen) can be determined and used advantageously. In its original state, it is infinitely large, since there is no contact between these elements. By the basic law U = R · I can be determined immediately if there is a contact, because in this case, this resistance drops abruptly to 0 down.

wobei

C

die Kapazität,

A

die wirksame Elektrodenfläche (m²),

d

den Plattenabstand (m),

l

die Leiterlänge,

ε₀

die elektrische Feldkonstante (8,85·10^–12 F/m), und

ε_r

die Dielektrizitätskonstante darstellt.

Second, the capacity or capacity change between the genanten elements can be evaluated. The capacity depends inter alia on the distance between the electrodes or the active screen and the electrodes and will rise to a maximum value as soon as the air gap d between them is very small (ie the thickness of the air gap tends to 0). The following formula can be used for this.

in which

C

the capacity,

A

the effective electrode area (m ² ),

d

the plate distance (m),

l

the conductor length,

ε ₀

the electric field constant (8,85 · 10 ^-12 F / m), and

ε _r

represents the dielectric constant.

in the Triggering algorithm can be both types of evaluation be deposited, which makes it possible to make a wrong decision to minimize the contact state.

Particular attention should be paid to the fact that there is little play or distance between the electrodes (and active screen). As a result, the elements of the sensor are technically in the elastic range of preforming. In a "misuse" case (ie, small deformations), there will be no permanent contact between the elements, the initial state would quickly re-adjust after the small deformation. As an example, the situation in a parking lot could be called when the door of a foreign vehicle is ruthlessly opened and causes a (bouncing) "bump" in the door of the ego vehicle. The electrodes 200 and 220 are short-circuited (which may not lead to tripping), but these electrodes are found 200 respectively. 220 or the active screen 250 immediately return to its original position by preloading.

For example, the triggering decision may be based on two different scenarios using the 6 and 7 are described in more detail:

Scenario 1:

The capacitive sensor 100c provides both the trigger signal and the plausibility signal (capacitance signal 600 and contact signal 610 ) for triggering the restraining means to an AND gate & according to the exemplary illustration 6 , Thus, at a collision time T ₀ or immediately thereafter, a triggering decision could be made and a restraining means activated. It should be noted that in the AND gate & the capacitance or capacitance change signal 600 and the contact or short-circuit signal 610 are somewhat delayed, but this time delay is low (in the single-digit millisecond range), so that for the release of the restraint means by a trigger signal 620 (For example, by means of the AND gate &) of a simultaneous arrival of the two signals 600 respectively. 610 in the evaluation unit (ie the AND gate &) can be assumed. It is advantageous in this case that no other sensor (PAS or PPS) is required for a side impact measurement. Such a sensor could be completely eliminated (which would mean a cost advantage) or it could be attached to the C-pillar (PAS) to provide better or faster protection for the rear occupants.

Scenario 2:

The capacitive sensor 100c delivers next to the capacity or capacity change value 600 the contact signal 610 only as an additional plausibility signal. It would be either the contact detection via the contact signal 610 or the capacitive object sensing via the capacitance signal 600 necessary for the signal of another sensor on the part of the sensor proposed here 100c (for example in an OR gate ≥ 1). The resulting link signal 700 from the capacity or capacity change value 600 and the contact signal 610 should be with a second signal 710 (For example, from an outsourced sensor such as the sensor 100a or 100b out 1 or from the central control unit 120 originates) to trigger the restraint by a trigger signal 720 in an evaluation unit (for example, again an AND gate &) to effect.

For the time sequence or the simultaneous presence of the signals in Scenario 2, the scenario stated for Scenario 1 applies here. It would be advantageous in this case that the system robustness would increase with regard to the "misuse susceptibility". It is disadvantageous in such an arrangement that no cost advantage would exist, because still other peripheral sensors 100a respectively. 100b would have to be used.

When another alternative embodiment may be instead of the "OR" gate (≥ 1) also an "AND" gate (&) can be used.

It should also be noted that, in the present case, the inventive approach can be found in particular in the 2 to 5 was shown or analyzed using the example of a 1-electrode system, wherein the vehicle panel was used as a counter electrode for measuring the capacitance changes. However, it will be apparent to one skilled in the art that a multi-electrode system may be considered. For example, a plurality of electrodes may be distributed over the door width, or be mounted at different heights on a door.

Finally, it should be noted that the present invention is also a special process 800 for triggering a restraining means of a motor vehicle, provides, for example in 8th is shown in more detail. The procedure 800 includes a step of providing 810 a first sensor signal representing a change in a capacitance, an inductance or a resistance of a sensor arranged on the motor vehicle. In a further step, the method comprises 800 a provision 820 a second sensor signal, which represents a short circuit of two electrodes and / or an electrode and an electrically conductive shielding layer between two electrodes of the sensor arranged on the motor vehicle. Finally, the process includes 800 in a third step triggering 830 the restraining means of the motor vehicle on the basis of the first and second sensor signals or on the basis of a sensor signal of a further sensor in combination with the first and / or second sensor signal.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• GB 2404443 A [0006]

Claims (10)

Sensor ( 100c ) for providing a signal ( 600 . 610 ) for detecting an impact of an object ( 260 ) on a vehicle ( 110 ), where the signal ( 600 . 610 ) can be provided using a first (A) and second (B) terminal contact, wherein the sensor ( 100c ) comprises the following features: - a holding element ( 240 ) for mounting the sensor ( 100c ) on a vehicle surface ( 200 ), wherein the retaining element ( 240 ) a first connection contact (A) for contacting the vehicle surface ( 200 ) or an electrically conductive layer ( 200 ) in the area of the vehicle surface ( 200 ); An electrically conductive shielding layer ( 250 ), which are opposite the vehicle surface ( 200 ) or an electrically conductive layer ( 200 ) in the area of the vehicle surface ( 200 ) is arranged electrically insulated; and an electrode ( 220 ) mounted on a holding element ( 240 ) facing away from the shielding layer ( 250 ) and which is electrically contactable via the second connection contact (B) and that of the shielding ( 250 ) is electrically isolated. Sensor ( 100c ) according to claim 1, characterized in that the retaining element ( 240 ) an electrically conductive layer ( 200 ), which in the attached state of the sensor ( 100c ) on the vehicle surface ( 200 ) is arranged. Sensor ( 100c ) according to claim 1 or 2, characterized in that the sensor ( 100c ) an evaluation unit ( 120 ), which are connected to the first (A) and second (B) terminal contact and / or the shielding layer ( 250 ) is electrically conductively connected and which is designed to generate a signal during a change in capacitance, induction and / or resistance between the first (A) and second (B) terminal contact. 600 ) first type and in the event of a short circuit between the shielding layer ( 250 ) and / or the first (A) and / or second (B) terminal contact a signal ( 610 ) of the second kind. Procedure ( 800 ) for triggering a restraint means ( 130a . 130b ) of a vehicle ( 110 ), the process ( 800 ) comprises the following steps: - providing ( 810 ) of a first sensor signal ( 600 ), which is a change in a capacitance, an inductance or a resistance of the motor vehicle ( 110 ) arranged sensor ( 100c represents; - Provide ( 820 ) of a second sensor signal ( 610 ) that short-circuits two electrodes (A, B) and / or one electrode ( 200 . 220 ) and an electrically conductive shielding layer ( 250 ) between two electrodes ( 200 . 220 ) of the sensor arranged on the motor vehicle ( 100c represents; and - triggering ( 830 ) of the restraint ( 130a . 130b ) of the motor vehicle ( 110 ) on the basis of the first ( 600 ) and second ( 610 ) Sensor signal or based on a sensor signal ( 710 ) of another sensor ( 100a . 100b ) in combination with the first ( 600 ) and / or second ( 610 ) Sensor signal. Procedure ( 800 ) according to claim 4, characterized in that in the triggering step ( 830 ) the first ( 600 ) or second ( 610 ) Sensor signal as a plausibility signal and the other of the first ( 600 ) or second ( 610 ) Sensor signal or the further sensor signal ( 710 ) as a trigger signal for triggering the restraint means ( 130a . 130b ) is used. Procedure ( 800 ) according to one of claims 4 or 5, characterized in that in the step of providing ( 810 ) the first sensor signal is provided when the change in capacitance, inductance or resistance is greater than a predefined variation value. Procedure ( 800 ) according to one of claims 4 to 6, characterized in that in the step of providing ( 820 ) the second sensor signal on the basis of a detected change in resistance and / or capacitance between two electrodes (A, B) and / or an electrode ( 200 . 220 ) and an electrically conductive shielding layer ( 250 ) between two electrodes ( 200 . 220 ) he follows. Procedure ( 800 ) according to one of claims 4 to 7, characterized in that the steps of providing ( 810 . 820 ) of the first and second sensor signals by evaluating a voltage or a current which occurs between or at connection contacts (A, B, 250 ) of a sensor ( 100c ) according to any one of claims 1 to 3. Computer program for performing steps of a method ( 800 ) according to one of claims 4 to 8, when the computer program is stored on a data processing system ( 120 ) is performed. Control unit ( 120 ) necessary for carrying out a method ( 800 ) is formed according to one of claims 4 to 8.