METHOD AND SYSTEM FOR DETECTING PROPERTIES OF A SURFACE SECTION ON AN AIRCRAFT

Description

Technical field

[0001] The present description relates to a method and a system for detecting properties of a surface section on an aircraft. Technical background

[0002] The standard procedure for mapping damage areas on an aircraft is usually a tactile method using calipers, dial gauges, and the like. Manual measurements are taken and documented in handwritten reports along with hand-drawn sketches.

[0003] WO 2014 / 014786 A1 discloses a portable device for 3D surface metrology that generates structured light measurement patterns and projects them sequentially onto a target surface. Features, contours, and textures of the target surface distort each projected measurement pattern image relative to the original measurement pattern. The device photographs each measurement pattern image, extracts measurement data from the detected distortions, and derives a result image from selected aspects of the measurement data. The device distorts the result image to compensate for distortions caused by the projector or the surface and projects the result image onto the measured surface, optionally with other information such as summaries, device status, menus, and instructions.

[0004] From US 2013 / 028478 A1, the thickness measurement of an object using a hand-held ultrasonic measuring head is known, with markers attached to the object and the measuring head, which are used to convert the measured values ​​of the measuring head into an object coordinate system.

[0005] For additional information, such as local material thickness in several positions of the damaged area, manual measurements with hand-held measuring devices are still necessary, which must be placed directly on the surface and read. Description

[0006] In In the usual damage mapping process, damage areas are sometimes not tracked over the entire service life of an aircraft. This means that an older damage area that was previously measured and found to be intact may be rediscovered and re-measured later, which can be time-consuming. Correlating the surface structure captured using a 3D method with separately recorded material thicknesses is complex and can be imprecise using existing methods.

[0007] It can be considered a task to propose a method and / or a system for recording properties of a surface section, which enables a precise correlation of surface structures and additional measurement data with little effort.

[0008] This object is achieved by the subject matter of independent claim 1. Further embodiments emerge from the dependent claims and from the following description.

[0009] A method for detecting properties of a surface section on an aircraft is proposed, comprising the steps of attaching a marking element with a plurality of grid markings next to a surface section on the aircraft, simultaneously optically detecting at least one area of ​​the marking element and at least one area of ​​the surface section by means of an optical detection device, removing the optical detection device, guiding a hand-held sensor device one or more times to a predetermined position relative to the marking element within the surface section and detecting a material property there, correlating the detected material property with the relevant position in a data set, and generating and storing a damage map,in which an optically detected structure of the surface section is combined with the additional material property at at least one position, wherein guiding the sensor device comprises projecting at least one laser line from the sensor device outwards and displacing the sensor device to align the at least one laser line with at least one of the raster markings.

[0010] The surface section to be examined can be a section of a body of the aircraft forming a surface. The surface section can in particular have a planar extension, which is formed, for example, by a planar component. The planar component could comprise an outer skin or be a part thereof. The surface can have a surface structure to be optically examined, wherein additional material properties are detected by the method according to the invention. For example, the surface section has a damaged area, which could be optically recognizable by a changed surface structure. A material thickness of the surface section or of a planar component forming the surface section is suitable as an additional material property to be detected.

[0011] The marking element serves to define a local coordinate system on the surface section, which will later be used to combine measurement results from different sources. The marking element can be implemented in the form of a sticker, a flat magnetic body, or other elements that can be permanently attached to the relevant surface, at least temporarily. It is also conceivable to implement a marking element during the process by projecting light signals.

[0012] On its side facing away from the surface receiving it, the marking element has at least one and preferably several grid markings, which are preferably optically detectable. The shape of the marking element is initially irrelevant to fulfilling its basic function. The marking element can be placed anywhere and, in principle, aligned in any way. The goal is to optically detect the surface section with the marking element arranged directly next to it, in order to subsequently align the sensor device relative to the marking element or the grid markings arranged thereon, separately from the optical detection device.

[0013] The optical detection device can be a device described in the aforementioned document WO 2014 / 014 786 A1. It is particularly designed to determine a surface structure of the surface section using optical methods, wherein the position of the surface section is also detected by the marking element during this determination. The measurement data supplied by the optical detection device can be transferred to a damage map in which the local coordinates can be described using the coordinate system defined by the marking element. The optical detection forms a first process in the method according to the invention. It can correspond to a conventional process for detecting a surface structure, as described in WO 2014 / 014 786 A1.

[0014] Once the surface section and the marking element have been optically detected with the optical detection device, as well as the damaged area, the optical detection device can be removed. It is then readily possible to perform additional measurements on the surface section, whose positions are then also measured relative to the marking element. This constitutes the second step of the method. For precise positioning of the sensor device in the local coordinate system, the sensor device has a corresponding laser unit configured to emit at least one laser line outwardly in order to align the at least one laser line with grid markings.

[0015] It is conceivable for the sensor device to have a support surface that is to be placed on the surface to be tested. It is also conceivable for the sensor device to have an input unit that is designed in the form of a button or the like. After positioning and a corresponding input, i.e. actuation of the button, a local measurement can be carried out. The at least one laser line is emitted by the sensor device in a specific, fixed direction outwards and aligned with at least one of the grid markings. Since the alignment of the laser line to the sensor device is fixed and the relative position of the marking element to the surface section is known after the optical detection, all subsequently measured material properties can be correlated with discrete positions of the surface section and stored in the damage map.

[0016] For this purpose, the sensor device could, for example, be coupled to a computing unit to transmit the measurement result to the computing unit after each measurement has been performed. An image from the optical detection device could be stored in the computing unit. The respective measurement result is added to a corresponding coordinate in the damage map. The method according to the invention thus allows for the convenient, automated and precise merging of different types of measurements.

[0017] In an advantageous embodiment, the marking element has two arms arranged at right angles to each other, each of which has grid markings. The two arms of the marking element can thus span a local coordinate system assigned to the damage site. Both arms could each have identical or different grid markings that function as coordinate tuples. The sensor device can be placed at different positions on the damage site, which can be clearly detected by the local coordinate system. This enables a clear and precise relationship between the location of the sensor device and the position in the local coordinate system.

[0018] In an advantageous embodiment, the sensor device is guided multiple times over a matrix-like arrangement of positions. This allows the surface of the surface section to be scanned gradually by the sensor device. It is conceivable to consider only a portion of the surface. For example, after the optical detection of the surface section, an area could be identified that exhibits more significant damage. This area could be specifically examined using the sensor device. The sensor device could examine different positions of the matrix-like arrangement one after the other by being placed successively at specific positions, in order to be placed at the next position after a measurement has been performed.

[0019] In an advantageous embodiment, the marking element and the surface section are completely captured by the optical detection device in one or more capture processes. If the surface section is relatively large, the capture range of the optical detection device may not be sufficient to enable complete imaging of the surface section. By using the marking element, which preferably has a surface extension adapted to the size of the surface section, the surface section can also be captured in multiple steps. In each of the steps, a partial area of ​​the surface section can be captured with a partial area of ​​the marking element. The individual partial images are combined to form an overall image based on the respectively captured parts of the marking element.Each subsequent measurement process with the sensor device then allows a correlation of the measurements with the overall image in a damage map.

[0020] In an advantageous embodiment, the sensor device projects cross lines. For this purpose, the sensor device has a cross-line laser unit that emits two laser lines running at right angles to each other. This allows two grid markings located on two arms of the marking element to be targeted simultaneously, so that the respective position of the sensor device is precisely recorded. It is advantageous to align the sensor device such that it has a predetermined orientation relative to the local coordinate system. This allows particularly advantageous scanning of flat areas one after the other with individual measurements of material properties and transferring them to the damage map.

[0021] In an advantageous embodiment, the sensor device is successively moved along the positions of the matrix-like arrangement such that the cross lines correlate with several pairs of grid markings on the two arms of the marking element. The movement can be performed manually, with the user visually checking the position of the sensor device based on the marking element and adjusting it accordingly.

[0022] In a further advantageous embodiment, the predetermined position is communicated by an optical, acoustic, or haptic signal, with detection being initiated by actuating an input unit after the sensor device has been guided. The computing unit could, for example, have a display unit that shows a user a position to be assumed. The user can then place the sensor unit on the displayed position and perform a measurement there. The measurement can be transmitted to the computing unit, which then assumes that the previously displayed position was assumed by the sensor unit and that the transmitted measured value belongs to this position. Thus, a series of individual measurements can be correlated fully automatically with positions within the damaged area.

[0023] The invention further relates to a system for detecting properties of a surface section on an aircraft, comprising at least one marking element with a plurality of grid markings for application next to a surface section on the aircraft, a hand-held sensor device, and a computing unit, wherein the computing unit is designed to record surface structure data from an optical detection device which is designed to optically scan a structure of the surface section together with the marking element, wherein the sensor device is designed to detect a local material property on the surface section, wherein the sensor device is designed to emit at least one laser line outwards in order to guide a user to move the sensor device to align the at least one laser line with at least one of the grid markings of the marking element glued next to the surface section,The computing unit is configured to correlate the detected material property with the relevant position in a data set, and the computing unit is configured to generate and store a damage map in which an optically detected structure of the surface section is combined with the additional material property at at least one position. The computing unit may contain software suitable for recording and processing structural data in the sense of the aforementioned method.

[0024] In an advantageous embodiment, the marking element has two arms arranged at right angles to each other, each of which has grid markings.

[0025] In an advantageous embodiment, the sensor device is designed to project cross lines. This allows, as explained above, the position of the sensor device to be adjusted and checked.

[0026] In In an advantageous embodiment, the sensor device has a support surface which is to be placed on the surface section in order to detect the material property, wherein the sensor device is designed to project the at least one laser line parallel to the support surface.

[0027] In In an advantageous embodiment, the sensor device comprises an ultrasonic measuring head. This could be intended to test material thickness. Short description of the characters

[0028] The following examples are described in more detail with reference to the accompanying drawings. The illustrations are schematic and not to scale. Like reference numerals refer to like or similar elements. They show: Fig. 1: A schematic representation of a surface with a surface section and a marking element. Fig. 2: A schematic representation of an optical detection device that detects a surface structure. Fig. 3: A schematic representation of a sensor device on the surface section. Fig. 4: A schematic representation of a method. Fig. 5: A schematic representation of a system. Detailed description of implementation examples

[0029] Fig. 1 shows a section of a surface 2 of an aircraft fuselage 4, on which a damaged area 6 is present as a surface section to be examined. To detect the properties of the damaged area 6, a method is proposed that operates in several stages and combines optically acquired topographic information with measurement results from other sensors.

[0030] Here, a marking element 8 is first glued next to the damaged area 6. In this exemplary embodiment, the marking element 8 is L-shaped and has two arms 10 and 12 arranged perpendicular to one another. These define a local coordinate system that is spanned directly next to the damaged area 6. The first arm 10 represents a first axis and the second arm 12 a second axis. Due to their rectangular arrangement, the coordinate system is Cartesian. It serves as the basis for a damage map to be generated. It is conceivable that the marking element 8 is glued to an aircraft-fixed coordinate system in such a way that at least one of the two arms 10 and 12 runs parallel to one of the main axes of the aircraft-fixed coordinate system.

[0031] The two arms 10 and 12 each have first grid markings 14, which are exemplified here as QR codes. These are easily digitally captured and could, for example, represent letters and / or numbers. Second grid markings 16 are provided on the arms 10 and 12, which are human-readable and contain letters (first arm 10) or numbers (second arm 12). By reading the first and second grid markings 16 on both arms 10 and 12, each position on the damaged area 6 can be assigned to the local coordinate system.

[0032] Fig. 2 schematically shows an optical detection device 18, which is placed on the surface 2 in order to project structured light measurement patterns 20 onto the surface 2 and thus also onto the damaged area 6. The light measurement patterns 20 are distorted compared to the original measurement patterns 20 due to the characteristic properties of the surface 2 at the damaged area 6. During the projection of each light measurement pattern 20, the detection device 18 photographs the surface 2 and can derive a surface structure of the damaged area 6 from the distortions detectable in the image. By photographing the surface 2, the marking element 8 is also detected, so that the topography of the damaged area 6 is always present in the local coordinate system defined by the marking element 8. After carrying out this first step of the method, the detection device 18 is removed from the surface 2.The marking element 8 remains on the surface 2 for a subsequent process in which further material properties are recorded.

[0033] Fig. 3 shows the damaged area 6, on which a sensor device 22 is arranged. The sensor device 22 could, for example, have an ultrasonic measuring head designed to determine a material thickness of the fuselage 4 at the local position of the sensor device 22. An input unit 23 in the form of a button can initiate a measuring process. The sensor unit 22 preferably has a communication unit, either wired or preferably wireless, with which a measurement result is transmitted to a computing unit (not shown here).

[0034] The sensor device 22 further comprises a first line laser unit 24 and a second line laser unit 26, which together form a cross-line laser unit 28 and are fixedly arranged on the sensor device 22. The first line laser unit 24 is designed to be arranged in the plane of the drawing in Fig. 3 first horizontal laser lines 30, while the second laser unit 26 is configured to emit second laser lines 32 in a direction perpendicular thereto. The laser lines 30 and 32 can be aligned with the marking elements 16 of the first arm 10 and the second arm 12, so that a user can directly read the position of the sensor unit 22 within the local coordinate system or place the sensor unit 22 at a desired position. Fig. 3 The first laser line 30 is aligned with the second grid marking "9" of the second arm 10, while the second laser line 32 is aligned with the second grid marking "F" of the first arm 10. The position of the sensor device 22 is then designated "F9." This position is known in the image of the damaged area 6 from the optical detection device 18.

[0035] A user can perform measurements at multiple positions on the damaged area 6 and transmit them to a computing unit in the local coordinate system. This allows a correlation to be automatically established between the surface structure of the damaged area 6 and the other material properties detected by the sensor unit 22.

[0036] The procedure is still in Fig. 4 shown. It begins with the step of applying 34 the marking element 8 with a plurality of grid markings 14, 16 next to the surface section 6, for example a damaged area, to the aircraft. This is followed by the simultaneous optical detection 36 of at least one area of ​​the marking element 8 and at least one area of ​​the surface section 6 by means of the optical detection device 18, after which the optical detection device 18 is removed again 38. The marking element 8 remains on the surface 2. In a further subsequent step, the hand-held sensor device 22 is guided 40 one or more times to a predetermined position relative to the marking element 8 within the surface section 6 and a material property is detected 42 there.The material properties thus recorded are correlated 44 with the relevant position in a data set, and then a damage map is generated 46 and stored 48, in which an optically recorded structure of the surface section 6 is combined with the additional material property at at least one position. As explained above, guiding the sensor device 22 comprises projecting at least one laser line 30, 32 outward from the sensor device 22 and displacing the sensor device 22 to align the at least one laser line 30, 32 with at least one of the grid markings 14, 16. The respective positions to which the sensor device 22 is to be guided 40 could be communicated to a user by emitting 50 an optical, acoustic, or haptic signal. The user can initiate the recording 42 by actuating 52 an input unit after guiding 40 the sensor device 22.

[0037] Fig. 5 shows a system 54 for detecting properties of a surface section 6, for example a damaged area, and has the marking element 8 with several grid markings 14, 16 for application next to the surface section 6 on the aircraft, the hand-held sensor device 22 and a computing unit 56.

[0038] The computing unit 56 is designed to record surface structure data from the optical detection device 18, which is shown schematically here and, in addition to an optics 62, has a processing unit 64 and a support frame 60 for placing the detection device 18 on the surface 2 to maintain a predetermined distance between the optics 62 and the surface 2. The optical detection device 18 is not necessarily part of the system 54, but can be used separately in different variants for the use of the method according to the invention. It is designed to optically scan a structure of the surface section 6 together with the marking element 8 and, in doing so, to provide structure data. This data can be transmitted to the computing unit 56 to be processed there.

[0039] The sensor device 22 is designed to detect a local material property, for example the thickness, on the surface section 6, wherein a user positions the sensor device 22 relative to the marking element 8, guided by the cross-line laser unit 28. A measurement can be initiated by actuating the input unit 23, which is arranged, for example, on the side of the sensor device 22 facing away from the surface 2.

[0040] The computing unit 56 is configured to correlate the recorded material property with the relevant position in a data set and, in doing so, to generate and store a damage map using the previously recorded structural data. The material properties are then clearly and precisely correlated with the structural data. For this purpose, the computing unit 56 can contain suitable software 58, which is suitable for recording and processing structural data in the sense of the aforementioned method and recorded material properties.

[0041] For example, the damage map could be a kind of heat map in which local height deviations of the surface 2 are shown, which are colored accordingly depending on local material thicknesses, whereby "hotter" colors, ie colors turning into red, can represent lower or insufficient material thicknesses. List of reference symbols

[0042] 2Surface 4Aircraft fuselage 6Surface section, e.g., damaged area 8Marking sticker 10First arm 12Second arm 14First grid markings 16Second grid markings 18Optical detection device 20Light measurement pattern 22Sensor device 23Input unit 24First line laser unit 26Second line laser unit 28Cross line laser unit 30First laser line 32Second laser line 34Applying marking sticker 36Optical detection 38Removing optical detection device 40Single or multiple movement of the sensor device 42Detecting a material property 44Correlating with position 46Generating damage map 48Lodging damage map 50Emitting signal 52Activating input unit 54System 56CPU 58Software 60Support frame

Claims

1. A method of detecting characteristics of a surface portion (6) on an aircraft, comprising the steps of: - applying (34) a marking element (8) with a plurality of grid markings (14, 16) next to a surface portion (6) to the aircraft, - simultaneously optically detecting (36) at least one region of the marking element (8) and at least one region of the surface portion (6) by means of an optical detection device (18), - removing (38) the optical detection device (18), - guiding (40) a hand-guided sensor device (22) once or several times to a predetermined position relative to the marking element (8) within the surface portion (6) and detecting (42) a material property there, - correlating (44) the detected material property with the relevant position in a dataset, and - generating (46) and storing (48) a damage map in which an optically detected structure of the surface portion (6) is combined with the additional material property at at least one position, characterised in that the guiding (40) of the sensor device (22) comprises projecting at least one laser line (30, 32) outwards from the sensor device (22) and moving the sensor device (22) to align the at least one laser line (30, 32) with at least one of the grid markings (14, 16).

2. Method according to claim 1, wherein the marking element (8) has two arms (10, 12) arranged at right angles to each other, each of which has grid markings (14, 16).

3. Method according to claim 1 or 2, wherein the sensor device (22) is guided several times on a matrix-like arrangement of positions.

4. Method according to one of the preceding claims, wherein the marking element (8) and the surface portion (6) are completely detected by means of the optical detection device (18) in one or more detection operations.

5. Method according to one of the preceding claims, wherein the sensor device (22) projects cross lines.

6. Method according to claims 2, 3 and 4, wherein the sensor device (22) is displaced successively on the positions of the matrix-like arrangement in such a way that the cross lines correlate with several pairs of grid markings (14, 16) of the two arms (10, 12) of the marking element (8).

7. Method according to one of the preceding claims, wherein the predetermined position is communicated in each case by an optical, acoustic or haptic signal, and wherein the detection (42) is initiated by actuating (52) an input unit (23) after guiding (40) the sensor device (22).

8. System (54) for detecting characteristics of a surface portion (6) on an aircraft, comprising: - at least one marking element (8) having a plurality of grid markings (14, 16) for application adjacent to a surface portion (6) on the aircraft, - a hand-guided sensor device (22), and - a computing unit (56), wherein the computing unit (56) is designed to receive surface structure data from an optical detection device (18) which is designed to optically scan a structure of the surface portion (6) together with the marking element (8), wherein the sensor device (22) is designed to detect a local material property on the surface portion (6), wherein the sensor device (22) is adapted to emit at least one laser line (30, 32) outwardly to guide a user to move the sensor device (22) to align the at least one laser line (30, 32) with at least one of the grid markings (14, 16) of the marking element (8) applied adjacent to the surface portion (6), the computing unit (56) being designed to correlate the detected material property with the relevant position in a dataset, and wherein the computing unit (56) is designed to generate and store a damage map in which an optically detected structure of the surface portion (6) is brought together with the additional material property at at least one position.

9. System (54) according to claim 8, wherein the marking element (8) has two arms (10, 12) arranged at right angles to each other, each of which has grid markings.

10. System (54) according to claim 8 or 9, wherein the sensor device (22) is designed to project cross lines.

11. System (54) according to one of claims 8 to 10, wherein the sensor device (22) comprises a support surface which is to be placed on the surface portion (6) for detecting the material property, and wherein the sensor device (22) is designed to project the at least one laser line (30, 32) parallel to the support surface.

12. System (54) according to one of claims 8 to 11, wherein the sensor device (22) comprises an ultrasonic measuring head.