Fiber composite component and method for locating a deformation in a fiber composite component

Abstract

Fiber composite component (8) for a motor vehicle (1), comprising several sensor devices (9, 10, 11, 12), each having at least one electrically conductive sensor wire (13, 14) integrated into a planar carrier medium, wherein each of the sensor devices (9, 10, 11, 12) is configured to detect voltage data (26) describing a voltage applied to the respective sensor wire (13, 14) and, depending on a change (27) of the detected voltage data (26) for the respective sensor device (9, 10, 11, 12), to detect a deformation of the respective sensor wire (13, 14), characterized in that the fiber composite component (8) has two sensor layers (17, 18) spatially separated from each other in a vertical direction, each of which has at least two of the sensor devices (9, 10, 11, 12) arranged next to each other in a transverse direction to the vertical direction, wherein Main extension directions of the sensor wires (13,14) the sensor devices (9, 10, 11, 12) of the two sensor layers (17, 18) are arranged intersecting, in particular perpendicular to each other, and the fiber composite component (8) is designed to provide location data (29) for the respective sensor device (9, 10, 11, 12) for which the deformation of the sensor wire (13, 14) was detected, which describe a location of the sensor device (9, 10, 11, 12) in the fiber composite component (8), wherein an intermediate textile layer (23) made of the planar carrier medium is arranged between the two sensor layers (17, 18).

Description

[0001] The invention relates to a fiber composite component for a motor vehicle. Furthermore, the invention relates to an underbody element for a motor vehicle comprising such a fiber composite component, as well as to a motor vehicle comprising such a fiber composite component. Furthermore, the invention relates to a method for locating a deformation in such a fiber composite component.

[0002] A motor vehicle that is designed at least for partially electric driving has a drive battery, which can alternatively be referred to as a traction battery. The drive battery typically has several battery cells and can be arranged in a floor area of ​​the motor vehicle. However, this arrangement of the drive battery in the motor vehicle means that if a force acts from below, for example an impact, the drive battery can be directly damaged. To avoid or at least reduce such damage, an underbody element can be provided for the drive battery, which is designed, for example, as an underrun guard. The underbody element ensures that the drive battery is not subjected to any direct force from the surroundings of the motor vehicle, but is protected by the underbody element.However, damage to the drive battery can still occur, for example, if an impact against the underbody element is so forceful that both the underbody element and, for example, a drive battery housing and / or the battery cells within the drive battery are damaged. Such damage can be referred to as drive battery intrusion. Drive battery intrusion can occur, for example, if the vehicle bottoms out while driving over a bollard.

[0003] To monitor the condition of the drive battery, it may be desirable to provide a location that, in the event of a force acting on the underbody element and / or the drive battery, particularly in the event of an intrusion, indicates, for example, the area where the force was applied. Taking this location into account, it is possible, for example, to specifically deactivate a portion of the drive battery's battery cells located in close proximity to the location of the intrusion. Precise localization of any damage caused by the force can therefore be quite interesting.

[0004] EP 3 901 010 A1 discloses a structural component for a vehicle body comprising a structural element and a sensor arrangement. The sensor arrangement is connected to the structural element and includes at least one optical fiber.

[0005] DE 10 2018 129 158 A1 discloses a safety device for a battery, wherein the safety device comprises an underbody part for a vehicle and several sensors arranged side by side. The sensors can detect deformation of the underbody part and determine the location of the deformation of the underbody part with spatial resolution.

[0006] DE 10 2017 206 663 A1 shows a battery pack with several deformation sensors arranged in separate segments of a protective plate of the battery pack.

[0007] DE 36 22 656 C1 shows a device for detecting damage to fiber composite materials, connected to an optical and acoustic signaling device and a damage storage device and / or a blocking device.

[0008] US 2005 / 0284232 A1 discloses a sensor system for use in monitoring the structural condition of a polymer matrix composite structure. The sensor system comprises a sensor formed from a conductive ink containing carbon nanofibers and a polymer resin, and a data acquisition system for acquiring and evaluating data from the sensor.

[0009] It is the object of the invention to provide a solution by means of which a location of damage to a component of a motor vehicle can be reliably determined.

[0010] This object is achieved by the independent and subordinate patent claims. Advantageous embodiments of the invention are disclosed in the dependent patent claims, the following description, and the figures.

[0011] A first aspect of the invention relates to a fiber composite component for a motor vehicle. The fiber composite component can be designed, for example, as an underbody element for a motor vehicle. The fiber composite component comprises a plurality of sensor devices, each having at least one electrically conductive sensor wire. The at least one electrically conductive sensor wire is integrated into a flat carrier medium. The carrier medium can alternatively be referred to as a carrier material or carrier layer. The carrier medium can, for example, be designed as a flat element on which the at least one sensor wire is evenly distributed over at least a partial area of ​​the entire surface of the carrier medium and covers this area. For example, a wire material of the sensor wire can be applied to a flat textile semi-finished product as a flat carrier medium. In this example, the carrier medium can be referred to as a textile material.Alternatively or additionally, the carrier medium can be designed as a film, for example, made of plastic, onto which the sensor wire is printed. The carrier medium can serve as a support structure that can facilitate the attachment of the sensor wire in the fiber composite component. The fiber composite component can, for example, be made from several layers of the flat carrier medium. This can achieve a particularly high strength of the fiber composite component.

[0012] The sensor wire is, for example, made at least partially of metal, in particular of a carbon fiber or a metal-coated plastic filament. The sensor wire can be a pure metal wire. The sensor wire can be made at least partially of an alloy of copper, nickel, and manganese, for example, of constantan with a copper content of 55 percent, a nickel content of 44 percent, and a manganese content of 1 percent. Within the flat carrier medium, the sensor wire of the respective sensor device can be arranged in a meandering pattern, for example. The sensor wire can therefore run in several bends, for example, and thus in a serpentine shape.

[0013] The at least one sensor wire is connected to a voltage detection device of the control device. The voltage detection device can be designed, for example, as a voltmeter, i.e., as a measuring device for detecting voltage data. In a simple embodiment, the sensor wire of the respective sensor device is designed, for example, as a simple loop, i.e., the entire sensor wire of the respective sensor device forms, for example, a rectangle, a square, an oval, or a circle, with the voltage detection device being integrated into the rectangle, square, oval, or circle.

[0014] Each of the sensor devices is designed to record voltage data describing a voltage applied to the sensor wire and to detect a deformation of the sensor wire depending on a change in the recorded voltage data for the respective sensor device. During operation, a current at a predetermined voltage flows through the sensor wire, wherein a deformation of the sensor wire leads to a change in the voltage. If a change in the recorded voltage is detected, conclusions can therefore be drawn about the deformation of the fiber composite component in the region of the sensor wire of the sensor device for which the change in voltage was observed. The change in the voltage data is observed, for example, in the event of an intrusion of a drive battery of a motor vehicle, if the fiber composite component is arranged, for example, between an environment of the motor vehicle and the drive battery.The stress data can be acquired using the stress detection device. The stress data can also be evaluated using the stress detection device and / or a control device of the fiber composite component. The control device of the fiber composite component can be a control device of the motor vehicle in which the fiber composite component is arranged.

[0015] The fiber composite component has two sensor layers that are spatially separated from one another in a vertical direction, each having at least two of the sensor devices. Each of the sensor layers has at least two of the sensor devices that are arranged next to one another in a direction transverse to the vertical direction. The transverse direction to the vertical direction is, for example, a longitudinal direction and / or a width direction of the fiber composite component. The planar carrier medium extends across the longitudinal direction and the width direction of the fiber composite component and has a comparatively small height in the vertical direction. The plurality of sensor devices are therefore arranged not only distributed across the surface of the fiber composite component, but also across its height. The sensor devices are namely distributed across at least two layers arranged one above the other in the vertical direction.Each sensor layer with the multiple sensor devices can be integrated into a common flat textile element.

[0016] A main extension direction of the sensor wires of the sensor devices of the two sensor layers is arranged so as to intersect. In particular, the main extension directions of the two sensor layers can be arranged perpendicular to each other. In other words, for example, in a first sensor layer, the main extension direction of the respective sensor wires can be oriented in the longitudinal direction, whereas in the second sensor layer, the main extension direction of the sensor wires arranged there is oriented in the width direction. This then leads to the sensor wires intersecting each other. In this example, the main extension directions of the sensor wires intersect such that they are arranged perpendicular to each other.It can be provided that the main extension directions of the sensor wires are arranged only substantially perpendicular to one another, i.e. at an angle to one another of between 80 degrees and 100 degrees, 85 degrees and 95 degrees, in particular 89 degrees and 91 degrees. The main extension direction is the direction in which a larger proportion of the sensor wire is directed. By arranging the main extension directions of the individual sensor wires in the two sensor layers arranged perpendicular to one another, a grid or lattice of intersecting sensor wires at a distance from one another can be formed, for example. If the main extension directions merely intersect, there can be an angle of greater than 0° and less than 90° between the main extension directions of the first sensor layer and the main extension directions of the second sensor layer, for example.

[0017] The sensor wires of the various sensor devices and sensor layers do not touch each other directly, as the two sensor layers are spatially separated. Thus, there is a distance between the two sensor layers that is greater than zero. This distance can be filled, for example, with a filling material, such as an intermediate textile layer.

[0018] The fiber composite component is designed to provide location data for the respective control device for which the deformation of the sensor wire was detected. The location data describe a location of the sensor device in the fiber composite component. Each individual sensor device is assigned a specific location in the fiber composite component, which is provided in advance, for example, to the tension detection device. The location data can be stored in a memory unit of the tension detection device and / or the control device. The corresponding location data is provided depending on which of the multiple sensor devices, which are arranged here in different sensor layers and next to one another in the transverse direction, detects a change in the detected tension data.It is intended that the corresponding location information described by the location data is provided only for the sensor device for which the change in the detected voltage data was detected.

[0019] Since the deformation of the respective sensor wire indicates damage to the fiber composite component, the location of damage to a component of a motor vehicle, namely the fiber composite component in the motor vehicle, can be reliably determined using the fiber composite component.

[0020] The invention provides that an intermediate textile layer made of the flat carrier medium is arranged between the two sensor layers. The carrier medium is an insulating material so that no electrical energy can be transmitted through the intermediate textile layer between the sensor wires of the sensor device of the two sensor layers. The carrier medium of the intermediate textile layer can differ in material from the carrier medium of the sensor layer, i.e., from the carrier medium into which the respective sensor wire is integrated. Alternatively, the intermediate textile layer and the carrier medium of the sensor layer can be made of the same material. This ensures that each sensor layer can record and evaluate the respective voltage data independently, and thus, ultimately, the deformations of the sensor wire can be reliably determined separately for both sensor layers.

[0021] One embodiment provides that the fiber composite component is designed to check whether the detected change in the recorded voltage data in at least one of the sensor devices is greater than a change threshold. The check can be carried out, for example, using an evaluation device and / or using the voltage detection device of the respective sensor device. The detected changes in the recorded change data can be provided in the form of change data that describe the detected change in the voltage data and thus the applied voltage. The change threshold is a predetermined value. Depending on where the fiber composite component was installed in the motor vehicle, a different change threshold can be specified.If the fiber composite component is designed as an underbody element of the motor vehicle, if the change limit is exceeded, it can be concluded that the drive battery, which is arranged vertically above the underbody element, has been intruded. However, if the change in the recorded voltage data is less than or equal to the change limit, it is assumed that only a slight impact, for example, against the fiber composite component occurred, which did not lead to any plastic and / or relevant deformation of the fiber composite component or, for example, adjacent components of the motor vehicle. Such a slight impact can be neglected, so that, for example, no location data is required.

[0022] It is therefore provided that a warning message is only generated if the detected change in the recorded stress data is greater than the change limit value. In other words, the fiber composite component is generally designed to generate the warning message if the detected change in the recorded stress data is greater than the change limit value. The warning message can, for example, be an acoustic and / or visual indication message that is output, for example, in the motor vehicle. The warning message can therefore be output, for example, by means of a loudspeaker device in the motor vehicle, which comprises at least one loudspeaker, and / or by means of a display device in the motor vehicle, which comprises at least one screen, for example a touch-sensitive screen. For this purpose, the warning message can comprise, for example, text, symbols and / or warning lights. The warning message can comprise the location data.It is therefore possible to specify exactly where the force acting on the fiber composite component was recorded.

[0023] Alternatively or additionally, the fiber composite component is configured to provide the location data associated with the sensor device in which the detected change is greater than the change limit only if the detected change in the recorded stress data is greater than the change limit. This reliably ensures that an actual localization of the force application occurs and / or information is only transmitted to an occupant via the warning message if an expected effect of the force application is sufficiently large because the change limit has been exceeded.This prevents the occupant, for example a driver, from being informed about every small impact against the fiber composite component, the effect of which only leads to a change in stress that is smaller than the change limit, and the location of the small impact in the fiber composite component, which he or she might perceive as disturbing and unnecessary.

[0024] In addition, one embodiment provides that each of the sensor devices extends over a partial area of ​​a surface of the fiber composite component arranged perpendicular to the vertical direction. The location data describing the location of the respective sensor device describes this partial area. If, for example, two sensor devices are arranged next to one another in a sensor layer, each of the sensor devices has a partial area that essentially comprises half of the entire surface of the fiber composite component if the two sensor devices are at least approximately the same size. This makes it possible for the surface of the fiber composite component to be divided, for example in the longitudinal direction, into several sections of equal size, and for one of the sensor devices to be arranged in each of the several sections. The section then represents the partial area.Likewise, the other sensor layer can be subdivided into a plurality of sub-regions, so that there too the plurality of adjacent sensor devices are assigned to respective fixed sub-regions. It is preferably provided that the sub-regions are approximately the same size. The plurality of sub-regions can be designated, for example, by means of numbers and / or letters. It can be provided, for example, that the at least two sensor devices arranged next to one another in the longitudinal direction in the first sensor layer are located in sub-regions 1 and 2, and the at least two sensor devices arranged next to one another in the width direction in the other sensor layer are located in sub-regions A and B. Preferably, four sensor devices can be provided in sub-regions 1, 2, 3 and 4 in the longitudinal direction and three sensor devices can be provided in sub-regions A, B and C in the width direction.Ultimately, this allows for simple location assignment, since each sensor device is assigned a predefined sub-area that describes the location of the respective sub-area. Furthermore, the location data describing the sub-area can be specified as coordinates, for example, as coordinates of an edge area of ​​the sub-area and / or a center point of the sub-area.

[0025] According to a further embodiment, the partial area of ​​each sensor device arranged in one of the two sensor layers overlaps with the partial areas of the at least two sensor devices arranged in the other sensor layer. Because the main extension directions of the sensor wires of the sensor devices intersect in different sensor layers and are arranged perpendicular to one another, for example, it is achieved that the partial areas of the individual sensor devices in different sensor layers also overlap at least in some areas. The fiber composite component is designed to determine overlap data if the location data has been determined for at least one sensor device in each of both sensor layers. The overlap data describe an overlap area of ​​the partial areas of the sensor devices for which the location data was determined.For example, precise localization can be carried out in the grid- or lattice-like structure comprising multiple sensor devices in the two sensor layers, since the actual location at which the deformation of the sensor wire occurred, for example due to a local impact, can be clearly determined based on the sub-areas assigned to the sensor devices in the various sensor layers. It can therefore be determined, for example, that location data was determined for sub-area 2 in the longitudinal direction and for sub-area C in the width direction, since the deformation of the sensor wire was detected for the sensor devices there. The overlap data can therefore describe a region 2C of the fiber composite component where sub-area 2 overlaps with sub-area C.In the above examples, a distinction is made between at least four overlap regions (1A, 1B, 2A, 2B) or preferably twelve overlap regions (1A, 2A, 3A, 4A, 1B, 2B, 3B, 4B, 1C, 2C, 3C, 4C). It can further be provided that the overlap data are determined only for the overlap region associated with the sensor devices in which the detected change in the recorded voltage data assumes the greatest value compared to all sensor devices of the fiber composite component. Ultimately, this allows the location of the damage to the drive battery to be identified particularly reliably, since the overlap regions enable precise location specification.

[0026] Furthermore, one embodiment provides that at least one further textile layer made of the flat carrier medium is adjacent to a side of the respective sensor layer facing away from the intermediate textile layer. The carrier medium of the further textile layer can differ in material from the carrier medium of the sensor layer, i.e. from the carrier medium into which the respective sensor wire is integrated. Alternatively, the further textile layer and the carrier medium of the sensor layer can be made of the same material. Ultimately, therefore, a layering of at least five layers is provided in the fiber composite component. In the vertical direction, a textile layer is arranged at the top, followed, for example, by the first sensor layer, followed by the intermediate layer, followed by the second sensor layer and finally followed by a lower textile layer.In addition, further textile layers and / or differently designed layers can be adjacent to the upper textile layer and / or the lower textile layer, so that the fiber composite component can be designed to be as thick as desired.

[0027] It can be provided that the two sensor layers are located in an edge region of the fiber composite component, viewed in the vertical direction. For example, the upper textile layer can represent an outer textile layer of the fiber composite component, whereas further additional textile layers can be adjacent to the lower textile layer. The lower textile layer then does not represent an outer textile layer of the fiber composite component in the vertical direction. In a preferred installation position of the fiber composite component as an underbody element in the motor vehicle, the edge region is preferably located adjacent to the drive battery. This ensures that the shocks actually acting on the drive battery, for example, can always be detected and located.

[0028] In one embodiment, it can be provided that the sensor wire is designed to change its electrical resistance when deformed. This means that the change in voltage and thus the deformation of the sensor wire is detected when the sensor wire changes its electrical resistance. If, for example, the fiber composite component deforms in the area of ​​the sensor device, the length and / or diameter of the sensor wire changes, which leads to a measurable change in resistance. The sensor wire is made, for example, from a metal such as constantan, which can change its length and / or thickness when deformed. Alternatively, the sensor wire can break, for example, when severely deformed, in which case the change in voltage is detected because current suddenly no longer flows through the sensor wire.

[0029] In particular, it is envisaged that the deformation is a force-induced deformation. In this case, as already described, an external force is applied to the fiber composite component with the integrated sensor wires, which leads to a mechanical deformation of the sensor wire, which can be elastic and / or plastic. Alternatively or additionally, the deformation can be temperature-induced. This requires that the sensor wires are made of a material that deforms measurably when the temperature changes. The material is preferably selected such that only strong temperature changes of, for example, at least 100 Kelvin, in particular at least 500 Kelvin, lead to a measurable deformation, for example at which the change limit is exceeded. A suitable material of this type is, for example, an alloy of copper, nickel, and manganese, such as constantan.It can further be provided that the change threshold is selected as a time-dependent value, so that, for example, only rapid temperature changes of, for example, over 500 Kelvin within seconds or minutes trigger a warning and / or provide location data. Such a rapid temperature change can occur, for example, due to local battery degassing of the drive battery or another defect in the drive battery, which could lead, for example, to a fire and / or overheating within the drive battery. If the sensor wires then noticeably bend due to the resulting temperature increase, the location from which the temperature increase originates can be reliably determined using the fiber composite component.In comparison, small temperature fluctuations, for example, from greater than 0 Kelvin to less than or equal to 20 Kelvin over a period of several minutes or hours, are preferably ignored by selecting the appropriate change threshold, as these indicate typical weather-related and / or time-of-day temperature fluctuations. Even in the case of temperature-related deformation of the sensor wires, the location where the temperature increase occurred can thus be reliably determined. This is always helpful, for example, when several spatially separated battery cells are provided in the vehicle, so that, for example, local measures can be implemented in response to the temperature increase in specific battery cells of the drive battery.

[0030] A further aspect of the invention relates to an underbody element for a motor vehicle. The underbody element is, for example, an underrun protection device. The underbody element is designed as a fiber composite component, as already described. In particular, when the underbody element is installed as intended in the motor vehicle, it is aligned such that the two sensor layers are each arranged in an upper region of the underbody element in the vertical direction of the motor vehicle. The drive battery of the motor vehicle is typically connected to the underbody element, so that the drive battery is arranged above the underbody element in the vertical direction. This ensures that the drive battery is located in spatial proximity to the two sensor layers, and thus the deformation of the sensor wires in the sensor layers is informative about the condition of the drive battery.

[0031] The embodiments described in connection with the fiber composite component according to the invention, each alone and in combination with one another, apply accordingly to the underbody element according to the invention.

[0032] The underbody element can have a foam insert arranged as a rigid intermediate layer between at least two textile layers. The two sensor layers are preferably arranged on a common side of the foam insert and separated from the foam insert by at least one textile layer. The foam insert is thus located, for example, adjacent to the upper or lower textile layer of the fiber composite component. A respective end of the sensor wire of the respective sensor device can be connected to a plug unit, which is, for example, integrated into the foam insert. The plug unit can be coupled to the voltage detection device and / or the control device by means of a plug via a free opening through at least one of the further textile layers. This makes it possible to supply the sensor devices with electrical energy.

[0033] An additional aspect of the invention relates to a motor vehicle with the described fiber composite component. The fiber composite component is designed in particular as an underbody element, as already described, and / or as a battery housing wall. The battery housing wall is preferably a battery housing base. Thus, for example, the fiber composite component can be integrated into a base of the battery housing arranged around the drive battery. Alternatively or additionally, the fiber composite component can be installed in a bumper of the motor vehicle or another component of the motor vehicle where precise locational deformations and / or temperature changes are of interest. The embodiments described in connection with the fiber composite component according to the invention and the underbody element according to the invention, individually or in combination with one another, apply accordingly, where applicable, to the motor vehicle according to the invention.

[0034] The motor vehicle can, for example, have the drive battery and the underbody element as a fiber composite component. The fiber composite component can be divided into several chambers, each of which houses one or more battery cells of the drive battery. The carrier medium with the sensor layers can then be arranged flatly over these chambers or even partially in the area of ​​the chambers. Thus, for example, distances can be maintained between the individual sensor devices of one or both sensor layers, at which, for example, side walls of the chambers can be arranged. Furthermore, several gaps can be provided in the carrier medium, along which, for example, the walls of the chambers run.

[0035] The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger car or truck, or as a passenger bus or motorcycle.

[0036] Furthermore, one aspect of the invention relates to a method for locating a deformation in a fiber composite component, as described above. Tension data describing a tension applied to the respective sensor wire is acquired by each sensor device of the fiber composite component. Depending on a change in the acquired tension data, a deformation of the sensor wire is detected for the respective sensor device. Location data describing a location of the sensor device in the fiber composite component are provided for the respective control device for which the deformation of the sensor wire was detected, wherein the location data locates the deformation in the fiber composite component.The embodiments described in connection with the fiber composite component according to the invention, the underbody element according to the invention and the motor vehicle according to the invention, individually or in combination with one another, apply accordingly, where applicable, to the method according to the invention.

[0037] The method is preferably carried out using the voltage detection devices of the sensor devices and / or the control device. The control device can alternatively be referred to as an evaluation device for the fiber composite component. The control device can be arranged at least partially within the fiber composite component and / or at least partially outside the fiber composite component in the motor vehicle. When arranged in the fiber composite component, the voltage data and / or the provided location data and / or the overlap data can be provided to, i.e., transmitted to, another control unit in the motor vehicle, for example, via a communication interface.

[0038] The invention also includes the control device. The control device can have a data processing device or a processor device configured to carry out an embodiment of the method according to the invention. For this purpose, the processor device can have at least one microprocessor and / or at least one microcontroller and / or at least one FPGA (Field Programmable Gate Array) and / or at least one DSP (Digital Signal Processor). Furthermore, the processor device can have program code configured to carry out the embodiment of the method according to the invention when executed by the processor device. The program code can be stored in a data memory of the processor device.

[0039] As a further solution, the invention also encompasses a computer-readable storage medium comprising instructions which, when executed by a computer or computer network, cause the computer to carry out an embodiment of the method according to the invention. The storage medium can, for example, be designed at least partially as a non-volatile data memory (e.g. as a flash memory and / or as an SSD - solid state drive) and / or at least partially as a volatile data memory (e.g. as a RAM - random access memory). The computer or computer network can provide a processor circuit with at least one microprocessor. The instructions can be provided as binary code or assembler and / or as source code of a programming language (e.g. C).

[0040] The invention also encompasses combinations of the features of the described embodiments. The invention therefore also encompasses implementations that each comprise a combination of the features of several of the described embodiments, unless the embodiments are described as mutually exclusive.

[0041] Exemplary embodiments of the invention are described below. Shown are: Fig. 1 a schematic representation of a motor vehicle with a fiber composite component; Fig. 2 a schematic plan view of the fiber composite component; Fig. 3 a schematic side view of the fiber composite component; and Fig. 4 shows a schematic representation of a signal flow graph of a method for locating a deformation in a fiber composite component.

[0042] The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments each represent individual features of the invention that can be considered independently of one another, each of which also develops the invention independently of one another. Therefore, the disclosure is intended to encompass combinations of the features of the embodiments other than those shown. Furthermore, the described embodiments can also be supplemented by further features of the invention already described.

[0043] In the figures, the same reference symbols designate elements with the same function.

[0044] In Fig. 1, a motor vehicle 1 is sketched. The motor vehicle 1 has an underbody element 2, which is arranged in a vertical direction (z-direction) of the motor vehicle 1 below a drive battery 3 of the motor vehicle 1. The drive battery 3 has several battery cells 4 and a battery housing 5. A battery housing base 6 of the battery housing 5 adjoins the underbody element 2 in a transverse direction to the vertical direction. The transverse direction to the vertical direction (z-direction) here is a longitudinal direction (x-direction) and / or a width direction (y-direction) of the motor vehicle 1. Furthermore, Fig. 1 a bumper 7 of the motor vehicle 1 is sketched.

[0045] In Fig. 2 shows a fiber composite component 8, which can be integrated, for example, into the underbody element 2, the battery housing base 6, and / or the bumper 7 of the motor vehicle 1. In the case of the bumper 7, it can be integrated into an outer wall of the bumper 7.

[0046] The fiber composite component 8 comprises a plurality of sensor devices 9, 10, 11, 12. Here, two sensor devices 9, 10 arranged next to one another in the x-direction and two sensor devices 11 and 12 arranged next to one another in the y-direction are highlighted. Four sensor devices 9, 10, 11, 12 can represent a minimum number of sensor devices 9, 10, 11, 12 of the fiber composite component 8. The x-direction corresponds to the longitudinal direction of the fiber composite component 8, the x-direction to the width direction, and the z-direction to the vertical direction. By way of example, a third sensor device 9, 10, 11, 12 is provided in the width direction (y-direction) and two further sensor devices 9, 10, 11, 12 are provided in the longitudinal direction (x-direction). Other numbers and arrangements of the sensor devices 9, 10, 11, 12 are possible.

[0047] Each of the sensor devices 9, 10, 11, 12 has at least one electrically conductive sensor wire 13, 14 integrated into a flat carrier medium. Each of the sensor devices 9, 10, 11, 12 also has a voltage detection device 15 that can detect a voltage applied to the respective sensor wire 13, 14. The voltage detection devices 15 are designed, for example, as voltmeters.

[0048] A control device 16 may also be provided, which is configured, for example, to evaluate the data provided by the voltage detection devices 15 and, if necessary, to transmit data to another control device of the motor vehicle 1. The control device 16 may be integrated into the fiber composite component 8 or arranged outside it. The control device 16 may be assigned to the motor vehicle 1.

[0049] In Fig. 2, two different sensor layers 17, 18 are highlighted, wherein the four sensor devices 9, 10, 11, 12, which are arranged next to one another in the longitudinal direction, i.e., here at least the sensor devices 9, 10, are located in the first sensor layer 17, and the three sensor devices 9, 10, 11, 12, which are arranged next to one another in the width direction, i.e., here at least the sensor devices 11, 12, are located in the second sensor layer 18. The first sensor layer 17 and the second sensor layer 18 are spatially separated from one another, so that, for example, no current can flow between one or more of the sensor wires 13, 14 of the first sensor layer 17 and one or more sensor wires 13, 14 of the second sensor layer 18.

[0050] The sensor wire 13 and the sensor wires 13 running parallel to it are arranged in the first sensor layer 17. The sensor wires 14, which are arranged perpendicular to the sensor wires 13 here, are assigned to the second sensor layer 18. This makes it clear that the fiber composite component 8 has two sensor layers 17, 18 that are spatially separated from one another in the vertical direction, each of which has at least two of the sensor devices 9, 10, 11, 12 that are arranged next to one another in a direction transverse to the vertical direction, i.e., in the longitudinal direction and / or in the transverse direction. It is also clear that the main extension direction of the sensor wires 13 is arranged parallel to the width direction, and the main extension direction of the sensor wires 14 is arranged in the longitudinal direction.This results in the main extension directions of the sensor wires 13, 14 of the sensor devices 9, 10, 11, 12 of the two sensor layers 17, 18 being arranged in an intersecting manner, in this case even perpendicular or at least substantially perpendicular to each other. The individual sensor devices 9, 10, 11, 12 thus form a grid and / or raster.

[0051] The individual sensor devices 9, 10 of the first sensor layer 17 are assigned a respective partial area 19 and the individual sensor devices 11, 12 of the second sensor layer 18 are assigned a respective partial area 20 which differs therefrom. The partial areas 19, 20 each comprise a part of a surface 22 arranged perpendicular to the vertical direction (see reference numeral 22 in Fig. 3) of the fiber composite component 8. The surface 22 is therefore spanned by the x and y directions.

[0052] Furthermore, overlapping areas 21 are purely exemplary for the four sensor devices 9, 10, 11, 12 in Fig. 2, in which the partial areas 19, 20 of the sensor devices 9, 10, 11, 12 each overlap. In the example sketched here, a total of twelve such overlap areas 21 are possible. If, for example, the individual partial areas 19 of the sensor devices 9, 10, 11, 12 are numbered consecutively from 1 to 4 in the longitudinal direction and the partial areas 20 of the individual sensor devices 9, 10, 11, 12 are designated with letters in the width direction, for example here with the letters A, B, C, the following overlap areas 21 result: 1A, 2A, 3A, 4A, 1B, 2B, 3B, 4B, 1C, 2C, 3C, 4C. These run row by row in the stated order, from left to right in the x-direction, from top to bottom in the y-direction.

[0053] Within each sensor device 9, 10, 11, 12, the sensor wire 13, 14 can be arranged as in Fig. 2, for example, cover a rectangular or square circumferential area. Alternatively or additionally, the sensor wire 13, 14 can be integrated in a meandering pattern into the flat carrier medium in the area of ​​the respective sensor device 9, 10, 11, 12.

[0054] In Fig. 3 is a cross section through the fiber composite component 8 of Fig. 2. It is clear that the two sensor layers 17, 18 are arranged spatially separated from each other. An intermediate textile layer 23 made of the planar carrier medium is arranged between the two sensor layers 17, 18. Furthermore, at least one further textile layer 24 made of the planar carrier medium is arranged on the side of the respective sensor layer 17, 18 facing away from the intermediate layer 23. Fig. 3 also highlights an upper region 25 of the fiber composite component 8, which comprises the first five layers in the vertical direction at the top, three of which are designed as a pure textile layer 24 including the intermediate textile layer 23, which each frame the sensor layers 17, 18 on both sides in the vertical direction.

[0055] In Fig.4 outlines a method for locating a deformation in the fiber composite component 8. In a first method step S1, stress data 26 is acquired using, for example, the individual stress detection devices 15, whereby this is carried out for all sensor devices 9, 10, 11, 12. In other words, the respective sensor device 9, 10, 11, 12 is designed to acquire the stress data 26, which describe the stress applied to the respective sensor wire 13, 14, using the stress detection device 15. In a method step S2, a change value is then determined depending on a change 27 in the acquired stress data 26, which describes the change 27 in the acquired stresses. This is done for each sensor device 9, 10, 11, 12. Based on the change 27 in the recorded voltage data for the respective sensor device 9, 10, 11, 12, a deformation of the sensor wire 13, 14 can ultimately be determined.

[0056] In a method step S3, it is checked whether the detected change 27 in the recorded voltage data 26 in at least one of the sensor devices 9, 10, 11, 12 is greater than a change limit 28. Only if this is the case, location data 29 can be provided in a method step S4. These data describe a location of the sensor device 9, 10, 11, 12 in the fiber composite component 8 for which the deformation of the sensor wire 13, 14 was detected because the change limit 28 was exceeded.

[0057] A check can then be carried out in a method step S5 to determine whether the location data 29 has been determined in both sensor layers 17, 18 for at least one of the sensor devices 9, 10, 11, 12 located there. If this is the case, overlap data 30 are determined in a method step S6, which describe the overlap area 21 of the sub-areas 19, 20 of the sensor devices 9, 10, 11, 12 for which the location data 29 were determined, since the change limit value 28 was exceeded for these. The location data 29 describe, among other things, the sub-area 19, 20 to which the sensor device 9, 10, 11, 12 is assigned, for which the voltage data 26 is provided.

[0058] Additionally or alternatively, if the verification step S3 is successful, a method step S7 may be provided in which a warning message 31 is generated and provided, for example, in the motor vehicle 1. The warning message 31 may be an acoustic and / or visual warning message 31.

[0059] It is envisaged that the sensor wire 13, 14 is made, for example, of carbon fiber, a metal-coated plastic filament, and / or constantan. The detected deformation causes a change in the electrical resistance in the sensor wire 13, 14. The deformation can be force-induced and / or temperature-induced. It is envisaged that the temperature-induced deformation only leads to deformations such that the change 27 in the recorded voltage data 26 can be greater than the change limit 28 during rapid and strong temperature increases of, for example, 500 to 1000 Kelvin within a few seconds or minutes.

[0060] In response to the warning message 31 and / or the provided location data 29, predetermined measures can be triggered, for example a shutdown or discharge of local battery cells arranged in the region of the overlap area; a warning to the driver by outputting the warning message 31 by means of an output device in the motor vehicle 1 and / or further measures, such as an immediate shutdown of the vehicle and a request to the driver to leave the motor vehicle 1.

[0061] Overall, the examples demonstrate a sensor matrix, damage localization, and tracking. Complete decoupling of the sensor layers 18, 19 in the x- and y-directions is achieved by arranging the support structure with integrated sensor wires 13, 14 in different sensor layers 18, 19. This avoids short circuits or complex insulation of the sensor wires 13, 14. A total of a defined number of sensor devices 9, 10, 11, 12 are arranged perpendicular to one another in the various sensor layers 17, 18. The corresponding sensor wires 13, 14 are directly integrated into the fiber composite component 8, but are located on different sensor layers 17, 18 and thus at different levels in the fiber composite component 8. Thus, they each form a separate circuit from one another, enabling particularly close overlap in the transverse direction to the vertical direction.This can be selected accordingly depending on the application. Ultimately, various fiber composite components 8 can be designed in this way, such as the underbody element 2, various protective plates, such as the bumper 7, and / or the battery housing 5. Firstly, the localization of the deformation occurring in a defined area is possible. For example, the resistance can be selected using software, which is selected as the change limit value 28, so that, for example, a quickly triggering or less quickly triggering process can be provided. This makes it possible to track and assign deformations that occur over a component life cycle. Furthermore, however, the localization of temperature increases, for example within the battery cell, triggered by local battery degassing downwards, is possible. The local battery degassing of individual battery cells 4 can thus be detected immediately.The localization of a local thermal event or a mechanical event can trigger defined measures, as already mentioned.

Claims

[1] Fiber composite component (8) for a motor vehicle (1), comprising a plurality of sensor devices (9, 10, 11, 12), each having at least one electrically conductive sensor wire (13, 14) integrated into a planar carrier medium, wherein each of the sensor devices (9, 10, 11, 12) is designed to detect voltage data (26) describing a voltage applied to the respective sensor wire (13, 14) and to detect a deformation of the respective sensor wire (13, 14) as a function of a change (27) in the detected voltage data (26) for the respective sensor device (9, 10, 11, 12), characterized byin that the fiber composite component (8) has two sensor layers (17, 18) which are spatially separated from one another in a vertical direction and which each have at least two of the sensor devices (9, 10, 11, 12) which are arranged next to one another in a transverse direction to the vertical direction, wherein main extension directions of the sensor wires (13, 14) of the sensor devices (9, 10, 11, 12) of the two sensor layers (17, 18) are arranged so as to cross one another, in particular perpendicular to one another, and the fiber composite component (8) is designed to provide location data (29) for the respective sensor device (9, 10, 11, 12) for which the deformation of the sensor wire (13, 14) was determined, which describe a location of the sensor device (9, 10, 11, 12) in the fiber composite component (8), wherein between the two sensor layers (17, 18) Intermediate textile layer (23) made of the flat carrier medium is arranged. [2] Fiber composite component (8) according to claim 1, wherein the fiber composite component (8) is designed to check whether in at least one of the sensor devices (9, 10, 11, 12) the detected change (27) of the detected voltage data (26) is greater than a change limit value (28) and, only if this is the case, to generate a warning message (31) and / or to provide the location data (29) to the sensor device (9, 10, 11, 12). [3] Fiber composite component (8) according to one of the preceding claims, wherein each of the sensor devices (9, 10, 11, 12) extends over a partial area (19, 20) of a surface (22) of the fiber composite component (8) arranged perpendicular to the vertical direction and the location data (29) describing the location of the respective sensor device (9, 10, 11, 12) describe the partial area (19, 20). [4] Fiber composite component (8) according to claim 3, wherein the partial area (19, 20) of each sensor device (9, 10, 11, 12) arranged in one of the two sensor layers (17, 18) overlaps with the partial areas (19, 20) of the at least two sensor devices (9, 10, 11, 12) arranged in the other sensor layer (17, 18), and the fiber composite component (8) is designed to determine overlap data (30) describing an overlap area (21) of the partial areas (19, 20) of the sensor devices (9, 10, 11, 12) for which the location data (29) were determined in each of the two sensor layers (17, 18). [5] Fiber composite component (8) according to one of the preceding claims, wherein at least one further textile layer (24) made of the planar carrier medium adjoins a side of the respective sensor layer (17, 18) facing away from the intermediate textile layer (23). [6] Fiber composite component (8) according to one of the preceding claims, wherein the sensor wire (13, 14) is designed to change an electrical resistance upon deformation, in particular a force-induced and / or temperature-induced deformation. [7] Underbody element (2) for a motor vehicle (1), wherein the underbody element (2) is designed as a fiber composite component (8) according to one of the preceding claims, wherein in particular in a proper installation position of the underbody element (2) in the motor vehicle (1), the two sensor layers (17, 18) are each arranged in the vertical direction of the motor vehicle (1) in an upper region (25) of the underbody element (2). [8] Motor vehicle (1) with a fiber composite component (8) according to one of claims 1 to 6, wherein the fiber composite component (8) is designed in particular as an underbody element (2) and / or as a battery housing wall. [9] Method for locating a deformation in a fiber composite component (8) according to one of claims 1 to 6, wherein tension data (26) describing a tension applied to the respective sensor wire (13, 14) are detected by means of each sensor device (9, 10, 11, 12) of the fiber composite component (8), a deformation of the sensor wire (13, 14) is determined for the respective sensor device (9, 10, 11, 12) as a function of a change (27) in the detected tension data (26), and location data (29) describing a location of the sensor device (9, 10, 11, 12) in the fiber composite component (8) are provided for the respective control device (16) for which the deformation of the sensor wire (13, 14) was determined, wherein the location data (29) locate the deformation in the fiber composite component (8).

Images