SYSTEM FOR THE STATE MONITORING OF A FIBRE COMPOSITE STRUCTURE

Abstract

A system for the state monitoring of a fiber composite structure, in particular of an aircraft or spacecraft, include a fiber composite structure; a multiplicity of state sensors which, on and/or in the fiber composite structure, are configured to detect state data of the fiber composite structure an energy store configured to store electrical energy for the supply of the state sensors in a rechargeable manner; an energy generating layer configured, on the fiber composite structure, to generate the electrical energy for the supply of the state sensors; and a data processing unit configured for wireless data communication with the state sensors for the further processing of the detected state data.

Claims

1. A system for state monitoring of a fiber composite structure comprising: a fiber composite structure; a plurality of state sensors which, on and/or in the fiber composite structure, are configured to detect state data of the fiber composite structure; an energy store configured to store electrical energy to supply the state sensors in a rechargeable manner; an energy generating layer configured, on the fiber composite structure, to generate electrical energy for the supply of the state sensors; and a data processing unit configured for wireless data communication with the state sensors for the further processing of the detected state data.

2. The system according to claim 1, wherein the energy generating layer is configured as a polymeric thin film solar cell.

3. The system according to claim 1, wherein the energy generating layer is fabricated integrally with the fiber composite structure.

4. The system according to claim 3, wherein the fiber composite structure is configured as at least one from fiber plastic laminate and fiber metal laminate, and a bottom electrode layer of the energy generating layer is cohesively connected to a top fiber composite layer of the fiber composite structure.

5. The system according to claim 3, wherein the fiber composite structure is configured as a fiber metal laminate, and a bottom electrode layer of the energy generating layer forms a top fiber composite layer of the fiber composite structure.

6. The system according to claim 1, wherein a top electrode layer of the energy generating layer is configured as light transmissive.

7. The system according to claim 6, wherein the top electrode layer comprises indium tin oxide.

8. The system according to claim 1, further comprising: a sensor node to which the state sensors are in each electrically connected and which is configured to receive the state data from the state sensors and to communicate said data wirelessly to the data processing unit.

9. The system according to claim 8, wherein the state sensors are each connected to the sensor node via an electrical line configured at least regionally as a printed line on a surface of the fiber composite structure.

10. The system according to claim 8, wherein the sensor node is configured to supply the state sensors with electrical energy from the energy store and/or the energy generating layer.

11. The system according to claim 8, wherein the energy store and/or the sensor node comprise a protective housing, which is secured to an underside of the fiber composite structure.

12. The system according to claim 11, wherein the protective housing comprises an inspection flap.

13. The system according to claim 11, wherein the protective housing is secured to the fiber composite structure directly below the energy generating layer.

14. The system according to claim 8, wherein the system comprises a multiplicity of sensor nodes with associated state sensors.

15. An aircraft or spacecraft comprising the system according to claim 1, wherein the fiber composite structure is configured in particular as a skin panel of a fuselage and/or of an airfoil of the aircraft or the spacecraft.

16. A system for state monitoring of a fiber composite structure comprising: a fiber composite structure; a first group of state sensors mounted to the fiber composite structure and configured to detect state data representative of at least one parameter of the fiber composite structure; a second group of state sensors mounted to the fiber composite structure and configured to detect state data representative of the at least one parameter of the fiber composite structure; a first rechargeable battery mounted to the fiber composite structure proximate to the first group of state sensors and connected to each of the state sensors in the first group by a respective electrical line mounted to the fiber composite structure, wherein the first rechargeable battery is configured to provide electrical power to the state sensors in the first group through the electrical lines; a second rechargeable battery mounted to the fiber composite structure proximate to the second group of state sensors and connected to each of the state sensors in the second group by a respective electrical line mounted to the fiber composite structure, wherein the second rechargeable battery is configured to provide electrical power to the state sensors in the second group through the electrical lines; a first photovoltaic module mounted to the fiber composite structure proximate the first rechargeable battery, and configured to generate electrical energy for the first group of state sensors and the first rechargeable battery; a second photovoltaic module mounted to the fiber composite structure proximate the second rechargeable battery, and configured to generate electrical energy for the second group of state sensors and the second rechargeable battery; and a data processing unit configured for wireless data communication with the first and second groups of state sensors and the data processing unit is configured to receive state data from the first and second group and process the received state data.

17. The system of claim 16, wherein the second rechargeable battery is not electrically connected to the first group of state sensors and the first rechargeable battery is not electrically connected to the second group of state sensors.

18. The system of claim 16, wherein the state sensors in the first and second groups include accelerometers and are configured to detect local accelerations of the fiber composite structure due to strikes on the structure.

19. The system of claim 16, wherein in the first group of the state sensors are mounted to an inside surface of the fiber composite structure and the second group of state sensors are mounted to an outside surface of the fiber composite structure.

Description

SUMMARY OF FIGURES

[0028] The present invention is explained in greater detail below on the basis of the exemplary embodiments indicated in the schematic figures, in which:

[0029] FIG. 1 shows a schematic view of a system for the state monitoring of a fiber composite structure of an aircraft or spacecraft in accordance with one embodiment of the invention;

[0030] FIGS. 2a and 2b show schematic sectional views of exemplary fiber composite structures from the system in FIG. 1;

[0031] FIG. 3 shows a schematic perspective view of a fiber composite structure obliquely from below with a sensor cell from the system in FIG. 1; and

[0032] FIG. 4 shows a schematic side view of an aircraft including the system.

[0033] The accompanying figures are intended to convey a further understanding of the embodiments of the invention. They illustrate embodiments and, in association with the description, serve to elucidate principles and concepts of the invention. Other embodiments and many of the advantages mentioned are evident in view of the drawings. The elements of the drawings are not necessarily shown in a manner true to scale with respect to one another.

[0034] In the figures of the drawing, identical, functionally identical and identically acting elements, features and components, unless explained otherwise are provided in each case with the same reference signs.

DETAILED DESCRIPTION

[0035] FIG. 1 shows a schematic view of a system 10 for the state monitoring of a fiber composite structure 1 of an aircraft or spacecraft 100 in accordance with one embodiment of the invention. FIG. 3 shows the fiber composite structure 1 in a schematic perspective view obliquely from below. FIG. 4 shows an aircraft with the system.

[0036] The system 10 comprises a plurality of sensor cells 22 each including a plurality of sensor nodes 11, which are in each case in wireless data communication with two cell associated data processing units 5 (one of the two data processing units 5 can serve here for example as a redundant backup unit for the case where the other data processing unit 5 fails). The data processing units 5 are in turn connected to a central system server 21 of the system 10 via electrical lines 12. The sensor nodes 11 each comprise a plurality of state sensors 2 (cf. FIG. 3) which, on and/or in the fiber composite structure 1, are configured to detect state data of the fiber composite structure 1. The fiber composite structure 1 can be in this case, for example, a skin panel of a fuselage and/or of an airfoil of the aircraft or spacecraft 100 in FIG. 4 (e.g. a passenger aircraft).

[0037] The state data detected by the state sensors 2 can comprise, for example, structural parameters of the fiber composite structure 1, such as temperature, mechanical load and/or stress or the like, damage to the fiber composite structure 1, accelerations of the fiber composite structure 1, etc. For this purpose, the state sensors 2 can comprise e.g. electronic sensors including detectors or antennas or the like, e.g. temperature sensors, acceleration sensors or piezoelectric transducers. The state sensors 2 can be arranged in a manner distributed over and in the fiber composite structure 1. In the example in FIG. 3, a total of four state sensors 2 are provided. Two of said state sensors 2 are secured on a surface 13 of an underside 15a of the fiber composite structure 1. A further state sensor 2 is fitted on an opposite top side 15b of the fiber composite structure 1. The fourth state sensor 2 is embedded into the fiber composite structure 1 (on the right in FIG. 3). By way of example, one of the state sensors 2 can be configured as an acceleration sensor. If an object in the vicinity of this state sensor 2 strikes the aircraft 100, the state sensor 2 recognizes the impact and can provide an estimation of the impact location and possibly of the affected region and/or the severity of the impact. Protective housing electric transducers, on the other hand, can be positioned e.g. within the fiber composite structure 1 and detect waves which propagate in the material and can provide a measure of resultant impact damage. During propagation through the material, said waves are influenced by discontinuities in the material, such as e.g. fractures, deformations or displacements on account of impacts or material fatigue. In this case, the propagation is influenced very specifically and the alterations in the propagated wave spectrum can be measured and analyzed in order to ascertain whether or not damage has occurred. In this way, possible damage to a fuselage or to airfoils of an aircraft 100 can be electronically recognized and assessed.

[0038] Each of the state sensors 2 is connected to the sensor node 11 via an electrical line 12, via which the state sensors 2 are supplied with electrical energy by the sensor node 11. The electrical line 12 is simultaneously configured to exchange the state data between the respective state sensor 2 and the sensor node 11, wherein said data are relayed (not depicted in FIG. 3) from the sensor node 11 once again wirelessly via an antenna to the data processing unit 5. Specifically, the electrical lines 12 in FIG. 3 are printed directly onto the surface 13 of the underside 15a of the fiber composite structure 1. In order to connect the electrical lines 12 to the corresponding state sensors 2, provision is made in part of feedthroughs through the fiber composite structure 1 (not depicted). Furthermore, the electrical lines 12 are connected to the sensor node 11 via a crimp connection 18 and connection cables 20 adjacent thereto. The sensor node 11 itself is situated together with a microcontroller and corresponding integrated circuits within a protective housing 14b composed of a metal material, which is secured to the underside 15a of the fiber composite structure 1 by means of connection elements 19 such as, for example, screws or the like. For mounting, maintenance and/or inspection purposes, the sensor node 11 furthermore has an inspection flap 16b on an underside.

[0039] The system 10 furthermore comprises an energy store 3, e.g. a (structural) battery configured to store electrical energy for the supply of the state sensors 2 in a rechargeable manner. The sensor node 11 is electrically connected to said energy store 3 for the operation of the state sensors 2. In the same way as the sensor node 11, an energy store 3, such as a rechargeable battery, also comprises a protective housing 14a composed of metal with an inspection flap 16a. The energy store 3 is in turn electrically connected via connection cables 20 to an energy generating layer 4 configured, on the fiber composite structure 1, to generate the electrical energy for the supply of the state sensors 2. In order to keep the length of the connection lines or cables as short as possible, both the energy store 3 and the sensor node 11 are secured to the fiber composite structure 1 directly below the energy generating layer 4.

[0040] FIGS. 2a and 2b illustrate sectional views of two fiber composite structures 1 of this type together with an energy generating layer 4 situated thereon. In both examples, the energy generating layer 4 is configured as a polymeric thin film solar cell comprising a light transmissive top electrode 8 on the basis of indium tin oxide, adjacent to which there is a heterojunction, which is in turn seated on a bottom electrode 6 composed of an aluminum alloy. In the variant in FIG. 2a, the energy generating layer 4 is fabricated integrally with the fiber composite structure 1, wherein the latter consists of fiber composite layers 17 fabricated alternately from an aluminum alloy and a glass fiber laminate. Specifically, in this case, a top fiber composite layer 9 simultaneously serves as a bottom electrode 6 of the energy generating layer 4.

[0041] In the alternative example in FIG. 2b, by contrast, the energy generating layer 4 is cohesively connected to the fiber composite structure 1, e.g. by means of adhesive bonding or welding. In this case, the fiber composite structure 1 comprises a multiplicity of fiber composite layers 17 composed of a carbon fiber reinforced thermoplastic, wherein the fibers in the fiber composite layers 17 are aligned alternately in different directions (indicated by hatching in FIG. 2b).

[0042] The system 10 comprises a multiplicity of sensor nodes 11 corresponding to that in FIG. 3, which in each case communicate wirelessly with one or more associated data processing units 5 and are configured as totally autonomous with regard to the energy supply. Accordingly, small groups of state sensors 2 can be positioned in a suitable region of the primary structure of the aircraft 100 and be operated there locally by way of the associated sensor node 11 (including energy store 3 and energy generating layer 4 connected thereto). Data and power lines thus at best have to be provided in a locally highly delimited region. The sensor nodes 11 can in turn communicate wirelessly with the data processing units 5 and thus ultimately with a central system server 21, which can be provided for example at a suitable location within the aircraft 100. Inter alia, on account of this configuration of the system 10, conducting cables and thus weight and ultimately costs can be saved to a considerable extent. The state sensors 2 are operated locally in a flexible and autonomous manner, wherein the energy store 3 can compensate for fluctuations in the energy feed of the energy generating layer 4 at least to a certain degree.

[0043] In the detailed description above, various features have been summarized in one or more examples in order to improve the rigorousness of the explanation. It should be clear here, however, that the above description is merely illustrative in nature, but on no account restrictive in nature. It serves to cover all alternatives, modifications and equivalents of the various features and exemplary embodiments. Many other examples will be immediately and directly clear to the person skilled in the art on the basis of his/her expert knowledge in view of the above description.

[0044] The exemplary embodiments have been chosen and described in order that the principles underlying the invention and the application possibilities thereof in practice can be presented in the best possible way. As a result, those skilled in the art can modify and utilize the invention and its various exemplary embodiments optimally with regard to the intended purpose of use. In the claims and the description, the terms including and having are used as linguistically neutral concepts for the corresponding terms comprising. Furthermore, a use of the terms a, an and one is intended not to exclude, in principle, a plurality of features and components described in this way.

[0045] While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms comprise or comprising do not exclude other elements or steps, the terms a or one do not exclude a plural number, and the term or means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.

LIST OF REFERENCE SIGNS

[0046] 1 Fiber composite structure [0047] 2 State sensor [0048] 3 Energy store [0049] 4 Energy generating layer [0050] 5 Data processing unit [0051] 6 Bottom electrode layer [0052] 7 Heterojunction [0053] 8 Top electrode layer [0054] 9 Top fiber composite layer [0055] 10 System for state monitoring [0056] 11 Sensor node [0057] 12 Electrical line [0058] 13 Surface of the fiber composite structure [0059] 14a, 14b Protective housing [0060] 15a Underside of the fiber composite structure [0061] 15b Top side of the fiber composite structure [0062] 16a, 16b Inspection flap [0063] 17 Fiber composite layer [0064] 18 Crimp connection [0065] 19 Connection element [0066] 20 Connection cable [0067] 21 System server [0068] 22 Sensor cell [0069] 100 Aircraft