Inspection method for the comb plate region of an escalator or moving walkway

Abstract

The invention relates to an inspection method (45) for the comb plate region (27) of an escalator (1) or a moving walkway by way of a mobile inspection device (40). When the inspection method (45) is carried out, a 3D recording (53) of the comb plate region (27) is captured by way of an imaging depth sensor (46) of the mobile inspection device (40), a scaled and rectified 3D surface image (53) is extracted herefrom, the 3D surface image (53) is spatially merged with a virtual 3D model (55) of the comb plate region and a height (h) of a comb gap (33) between a tread surface (21) imaged in the 3D surface image (53) and a surface (61) of the comb underside (34) of the virtual 3D model (55) is determined. The determined height (h) is compared with limit specifications (hmin, hmax) for the height (h) of the comb gap (33) and an information signal (HS1) is output if the determined height (h) deviates from the limit specifications (hm in, hmax).

Description

[0001] Inspection procedure for the comb plate area of ​​an escalator or

[0002] Fahrsteiges

[0003] The present invention relates to an inspection method for the comb plate area of ​​an escalator or a moving walkway by means of a mobile inspection device.

[0004] Escalators and moving walkways have been used for many decades in public spaces with high pedestrian traffic, such as subways, shopping centers, and airports. Their operational safety depends in particular on the design of the interfaces between moving and stationary components that are accessible to users.

[0005] In escalators and moving walkways, these interfaces are side gaps located between the moving conveyor belt and the stationary base plates arranged on both sides of the conveyor belt. Further interfaces are comb gaps located between the conveyor belt and stationary combs. The combs are fixedly mounted in comb plate areas and located in two opposite access areas of the escalator or moving walkway. When correctly and reliably arranged, the web / groove structures of the conveyor belt and the comb teeth of the comb plates engage with a predetermined comb gap, allowing the conveyor belt to be retracted or extended under the comb plates without contact, preventing foreign objects from entering the comb gap.Therefore, maintaining the specified comb gap between the web / groove structures of the conveyor belt and the comb teeth of the comb plates is very important for the safe operation of the escalator or moving walkway. If, for example, the comb gap is too large due to wear, or the comb teeth of the comb plates are bent or even broken, there is a risk that an object carried by a passenger will become trapped in the comb plate gap, causing the passenger to be injured. If, for example, an external foreign object such as a coin becomes trapped, this can also lead to incorrect positioning of the conveyor belt relative to the base plates arranged on either side, causing one of the two side gaps to become too large and creating a latent danger for the passenger. Therefore, the side gaps and the comb gaps in the comb plate area of ​​an escalator or moving walkway are periodically inspected.This inspection is very time-consuming and requires a high level of knowledge and skill from a service technician to carry out the inspection correctly and make an assessment appropriate to the situation.

[0006] The object of the present invention is therefore to provide an inspection method which enables even a less qualified service technician to inspect the comb plate area quickly and correctly.

[0007] This problem is solved by an inspection method for the comb plate area of ​​an escalator or moving walkway using a mobile inspection device. This can be, for example, a specially manufactured inspection device or a suitably equipped tablet, smartphone, or laptop. The mobile inspection device has at least a user interface, a digital storage medium, a processor, an imaging depth sensor, and a software application, at least temporarily stored in the storage medium, containing the required steps of the inspection process.

[0008] The inspection procedure includes in particular the following procedural steps, although these do not necessarily have to be carried out in this order.

[0009] In one step of the inspection process, a depth sensor on the mobile inspection device captures a 3D image of all combs and their adjacent surface areas in a comb plate area of ​​the escalator or moving walkway. The feature "all combs and their adjacent surface areas" means that the entire comb plate area, from one base plate through all adjacent combs in the comb plate area to the second base plate, is imaged in the 3D image. The feature suffix "3D" means that all features with this suffix have a three-dimensional, spatial structure. Since the combs and the web / groove structure of the conveyor belt interlock, a section of a tread surface of the conveyor belt of the escalator or moving walkway is logically also included in the 3D image.

[0010] In a further step, a 3D surface image of the comb plate area is extracted from the 3D image. A 3D surface image is generated or extracted from the three-dimensional point cloud of the 3D image using well-known algorithms from electronic image processing methods, which are integrated into commercially available graphics programs, photo editing programs, image analysis and video analysis programs, etc., or are available as open source software modules. Edge areas that are not of interest can be eliminated manually or automatically.The 3D surface image, for example, is a further processable, three-dimensional vector graphic and contains at least the surfaces captured in the 3D image of all adjacent combs of the imaged comb plate area, as well as surface areas of base plates that are laterally adjacent to the combs and of the conveyor belt tread located in the comb plate area. Extracting the 3D surface image also includes rectification and scaling. This can be done in different ways and may also depend on whether a single 3D image of the entire comb plate area was captured or whether the 3D image was recorded in the form of a digital 3D film sequence with multiple frames.

[0011] In other words, the 3D surface image is essentially a digital 3D surface model, preferably at a scale of 1:1. This essentially comprises the areas of the comb plate region captured in the 3D image. During extraction, the content of the 3D image (the imaged comb plate region in the individual 3D image or in each frame of the 3D film sequence) is rectified and scaled to a scale of 1:1. While a scale of 1:1 is advantageous, it is not mandatory. It is only important that the proportions of the 3D surface image match the virtual 3D model described below.

[0012] In a single 3D image, all ridges are fully mapped to the 3D image, so that their component boundaries, such as corners, edges, and joint gaps, can be easily identified as fixed points on the 3D surface image using appropriate analysis algorithms. The image recognition and processing algorithms required for this are well-known and widely used in image processing programs, which is why a detailed description of these algorithms is not provided here. To identify prominent edges, corners, and joint gaps, an appropriately trained AI program module (Artificial Intelligence) can be used, for example. 3D surface images of the comb plate area or an individual ridge, captured from various angles or camera perspectives, can be used as a training basis for the AI ​​program module.

[0013] Of course, service technicians can also define fixed points manually by enlarging the 3D image on the inspection device's user interface using the zoom function and defining prominent locations on the image as fixed points, for example, by positioning markers provided by the software application. The markers are then linked to the position data of the marked pixel and "carried along" during subsequent process steps.

[0014] The conversion parameters for rectification and scaling depend on the spatial position of the imaging depth sensor relative to the comb plate area and, if applicable, to fixed reference points such as a fixed, prominent corner of a ridge. If the actual distances between two reference points, such as the ridge length, are stored in the storage medium, the corresponding conversion parameters can be determined for each captured pixel of the 3D surface image.

[0015] If the software application is implemented on a mobile device (smartphone, tablet, laptop), the spatial position of the imaging depth sensor can be determined for each pixel of the 3D image, if necessary, using position data from the built-in three-axis position sensor. Using these conversion parameters and well-known processing algorithms used in image processing programs and 3D CAD programs for rectification and scaling of three-dimensional digital images, the 3D surface image can be generated from the 3D image. Alternatively, rectification and scaling can also be performed using a uniquely identifiable virtual 3D model stored on the storage medium.For example, a scaling factor can be calculated based on the edge length of a ridge of the 3D model and the 3D surface image, and the surface image can be scaled to the 3D model. The virtual 3D model is preferably stored at a scale of 1:1. The spatial rectification of the 3D surface image can also be performed based on the spatial position of edges and joints of the ridges.

[0016] In a further step, a virtual 3D model of the comb plate area is retrieved from a digital storage medium, wherein the virtual 3D model has at least virtual 3D comb models of the comb plate area in a predetermined arrangement. The virtual 3D model can, for example, have been generated using a 3D CAD system and only comprise the 3D comb models arranged next to one another in the intended spatial position. Of course, further 3D model modules can also be present, for example a 3D model module of a comb plate on which the combs are arranged, lateral sections of the base plates, parts of a comb plate support, and the like. The virtual 3D model can, for example, also be retrieved from a digital twin that represents the escalator or moving walkway to be inspected.

[0017] In a further step, the 3D surface image and the virtual 3D model are spatially merged. In other words, the 3D model is inserted at the correct location in the rectified and scaled 3D surface image. The individual ridges have such a small footprint that they can easily be fully mapped onto the 3D image. Accordingly, their component boundaries are present as edges and joints on the 3D surface image. The spatial alignment and correctly positioned insertion of the virtual 3D model into the 3D surface image can be achieved based on the spatial location of these edges and joints. The image recognition and image processing algorithms required for this are well-known and widely used in image processing programs, which is why a detailed description of these algorithms is not provided here.For example, a suitably trained AI (Artificial Intelligence) program module can be used to identify prominent edges, corners, and joint gaps. 3D surface images of the comb plate area, captured from various angles or camera perspectives, can be used as a training basis for the AI ​​program module.

[0018] In a further step, the height of a comb gap is determined between the tread surface depicted in the 3D surface image and a comb undersurface structure of the virtual 3D model. Since the tread surface has a web / groove structure that meshes with the comb teeth, the comb gap extends in a meandering pattern across the width of the conveyor belt between the two base plates. The height of the comb gap relevant for the inspection is the vertical clearance between the highest surface of a web of the tread surface and an overlying tooth base of the comb, or the clearance between a groove base of the tread surface and an overlying tooth tip surface of the comb. The previously used characteristics "overlying" and "vertical" refer to the intended operating position of these components.

[0019] In a next step, a comparison is made with the height limits for the comb gap retrieved from the digital storage medium. If the determined height deviates from the limits, a first warning signal is issued. The function and effects of the first warning signal are described in more detail below.

[0020] The advantage of the method described above is that the comb gap is assessed not only based on the visible surfaces, but also based on the hidden surfaces available through the inserted 3D model, particularly the underside of the combs. This eliminates the need for comparison with a previously recorded reference image, as disclosed, for example, in EP 3 299 330 B1. Reference images are only useful if the inspection device is installed stationary at the site of use. Since the camera perspective changes each time the inspection process is performed when using the mobile inspection device as envisaged according to the invention, previously recorded reference images are unusable.In addition, the mobile inspection device is intended to analyze a large number of different escalators and moving walkways, which further complicates the handling and assignment of reference images taken during commissioning or after a repair.

[0021] Reference images taken immediately before inspection are unsuitable for the inspection method according to the invention anyway, because they can be inaccurate depending on the situation and then produce systematically erroneous results. For example, if chewing gum is stuck to the combs, this can lead to a falsification of the heights of the combs relative to the tread. By inserting the 3D model into the 3D surface image, its alignment is achieved, as described above, based on the spatial position of the edges and joints of the combs, so that such "bumps and dents" are ignored in the 3D surface image. Of course, the usually slightly curved surface of the combs can also be used for the spatial alignment of the 3D model, whereby the largest common contact area between the 3D surface image and the 3D model is used for positioning.

[0022] In one version of the inspection method, a minimum side gap width and a maximum side gap width between the tread and the adjacent base plate or the corresponding extracted surface area are measured on both sides of the tread from the scaled and rectified 3D surface image. As a basis for these measurements, two measuring points can be defined for each side gap. Their spacing preferably corresponds to one step length of a conveyor belt for escalators or, for moving walks, three pallet lengths of the pallet belt. If necessary, the measuring points can be determined automatically by identifying gaps between the steps or pallets from the 3D surface image and defining their opening into the step gap (corner of a step or pallet) as measuring points.According to applicable standards such as EN 115-2, each of the side gaps must not be wider than 4 mm, and their sum must not be wider than 7 mm. Accordingly, the two measured values ​​of the maximum side gap width must not be greater than 4 mm, and their sum must not be greater than 7 mm. In other words, the maximum side gap widths are compared with the side gap width limits retrieved from the digital storage medium, and a second warning signal is issued if the determined side gap width deviates from the limit values.

[0023] In a further embodiment of the inspection method, the minimum side gap width and the maximum side gap width of one of the two side gaps are used to determine the angle of inclination of the tread surface relative to the base plate. The inclination of the tread surface relative to the base plate can be caused, for example, by conveyor chains of different lengths, which exhibit varying degrees of wear due to asymmetrical loads (standing on the right, walking on the left). The inclination angle is then compared with the limit values ​​for the inclination angle retrieved from the digital storage medium. If the determined inclination angle deviates from the limit values, a third warning signal is issued.

[0024] In a further embodiment of the inspection method, the 3D image is captured in the form of a digital 3D film sequence of the comb plate area, wherein the digital 3D film sequence shows the comb plate area from the first base plate to the opposite, second base plate in several frames. To generate the 3D surface image, prominent fixed points, such as the aforementioned joints and edges of the combs, are automatically defined in the frames of the digital 3D film sequence and used to rectify and scale the 3D surface image. A prominent fixed point of the aforementioned type can also be a comb edge, a fastening screw of the comb, or a corner of the comb.

[0025] The generation of the 3D surface image involves rectifying and scaling the surfaces and contours depicted in the frames, which is advantageous due to the changing spatial position of the imaging depth sensor of the inspection device relative to the captured comb plate area. Furthermore, the generation process involves composing the 3D partial surfaces of the comb plate area depicted in the frames to create the 3D surface image. Here, too, the fixed points are used to spatially align the depicted 3D partial surfaces to one another. As already mentioned above, the image recognition and image processing algorithms required for this are well-known and widely used in image processing programs and CAD systems, which is why a detailed description of these algorithms is not provided here.The required distances to these fixed points are measured by the imaging depth sensor for each fixed point captured in the frames of the 3D recording and can be used by the image processing algorithms.

[0026] In a further embodiment of the inspection method, the 3D surface image is analyzed by an analysis module, and based on its analysis data, a suitable 3D model is retrieved from a model database stored on the digital storage medium. The analysis module can be a program component of the software application, which also contains the previously described steps of the inspection method. However, the analysis module can also be a computer program independent of the software application, which communicates and exchanges data with the software application executing in the processor via suitable communication means (protocols, etc.). The analysis module can be part of the AI ​​program module described above.

[0027] In an alternative version of the inspection process, the correct 3D model can also be determined by scanning a barcode or QR code attached to the escalator or moving walkway to be inspected. After scanning, a 3D model associated with the barcode or QR code is retrieved from a model database stored on a digital storage medium.

[0028] In an alternative version of the inspection process, the correct 3D model can also be obtained via a query from the mobile inspection device. To do this, the device queries an identification number from the control system of the escalator or moving walkway. Using the identification number, an associated 3D model is retrieved from a model database stored on a digital storage medium.

[0029] In a further version of the inspection process, the mobile inspection device compares the contours of all combs between the 3D surface image and the 3D model. A different contour profile indicates damage to the comb teeth. The existing differences are checked for unacceptable deviations in the tooth shapes of the comb teeth and / or missing comb teeth, for example, by determining orthogonal distances between the contour of the 3D model and the contour of the 3D surface image and comparing them with specified limits for these distances. Of course, the contour comparison can also be performed by analyzing difference surfaces, whereby the visible surface of a comb is compared between the 3D model and the 3D surface image. Nearly 100 percent coverage (nearly zero difference surface) indicates a flawless comb condition.For example, a deviation of 2 percent of the visible comb surface indicates an unacceptable deviation in the tooth shape of the comb teeth or missing comb teeth. If one of the measured distances deviates from the limit specifications or the difference area is too large, an unacceptable deviation in the tooth shape of the comb teeth and / or missing comb teeth exists, and a fourth warning signal is issued.

[0030] In a further embodiment of the inspection process, if a fourth warning signal is present, the components affected by the deviations that require replacement are marked on the 3D surface image of the comb plate area. Since the component boundaries can be easily identified using appropriate image processing algorithms, these component boundaries or the surface within these component boundaries can be highlighted in color. The marked 3D surface image is displayed on the user interface (screen, touchscreen) of the mobile inspection device. This allows a service technician operating the inspection device to immediately identify which components need to be replaced.

[0031] In a further embodiment of the inspection process, based on the fourth warning signal, the component identification numbers of the components affected by the deviations and to be replaced are displayed by the inspection device and / or sent to a staging facility. The staging facility checks the inventory, reports a date to the mobile inspection device indicating when and where the requested components will be available, and provides the requested components. If necessary, a file (e.g., a PDF file or video clip) containing the specific assembly instructions for the requested components is also sent to the inspection device along with the staging confirmation. The service technician can then view these instructions on its user interface.If the inspection device detects that at least one of the four warning signals is present, in a further embodiment of the inspection procedure, the inspection device can put the control system of the escalator or moving walkway into maintenance mode. This maintenance mode can be graded depending on the importance of the warning signal for operational safety and the extent of the detected deviation from the limit specifications. The highest level (for example, if many teeth of a comb are broken or the comb gap is too large) means that the detected defects are so serious that the ferry operation of the escalator or moving walkway is blocked until repairs are carried out. A medium level (for example, if a tooth of a comb is deformed) can, for example, define a time window in which ferry operation at nominal speed or ferry operation at reduced speed is still possible.A low level (for example, if the comb gap or one of the side gaps is close to the permissible limit) can mean that there is no impact on ferry operations, but the service technician is only required to schedule a maintenance appointment when he will carry out the repair.

[0032] To carry out the aforementioned method, a mobile inspection device is required, which has at least a user interface, a digital storage medium, a processor, an imaging depth sensor, and a software application, at least temporarily stored in the storage medium, containing the required process steps of the inspection method. For example, a combination of a CCD camera and a LIDAR sensor, a laser scanner, a radar sensor, or a TOF camera can be used as the imaging depth sensor. The mobile inspection device can be a device specifically designed for this purpose.Since many mobile phones (smartphones) and tablets now have suitable imaging depth sensors, particularly TOF cameras or a combination of LiDAR and CCD sensors, these devices contain all the necessary hardware components, so that only the corresponding software application with the inspection process steps needs to be loaded into their storage medium. The inspection process steps programmed in the software application are processed by the processor following input from the service technician via the user interface.The mobile inspection device preferably has a communications module that can be connected to a communications module of at least one of the following devices for data exchange as needed: a control system of an escalator or moving walkway, a central monitoring device, a spare parts supply facility, or an internet network node. The functionality of the inspection device can be significantly expanded by, for example, automatically ordering spare parts, sending safety notices, and / or disabling the escalator's or moving walkway's travel functions via the communications module.

[0033] Furthermore, certain functions of the software application can be executed decentrally, for example, in a cloud. Such outsourced functions include the analysis module, the extraction of the 3D surface image from the 3D images, the storage of 3D models and boundary specifications in suitable databases, and so on. This allows the most computationally intensive and memory-intensive process steps to be outsourced, freeing up processor and memory resources in the inspection device.

[0034] Embodiments of the invention are described below with reference to the accompanying drawings, whereby neither the drawings nor the description are to be interpreted as limiting the invention. The figures are merely schematic and not to scale. Identical or equivalent features have the same reference numerals. They show:

[0035] Figure 1: schematically shows a sectional side view of an escalator and its most important components as well as peripheral devices for carrying out associated process steps of an inspection process;

[0036] Figure 2: a three-dimensional partial view of the upper access area shown in Figure 1 with a comb plate area and a smartphone with a software application that turns it into a mobile inspection device;

[0037] Figure 3: a cross-section through the comb plate area shown in Figure 2; Figure 4: a plan view of a section of the comb plate area shown in Figure 2;

[0038] Figure 5: a flow chart of the inspection procedure with process steps; and

[0039] Figure 6: a plan view of a section of the comb plate area shown in Figure 2 with possible damage to comb teeth of the combs arranged in the comb plate area.

[0040] Figure 1 shows a schematic, sectional side view of an escalator 1 and its key components. Escalator 1 can be used to transport people, for example, between two levels E1 and E2 of a building.

[0041] The escalator 1 has a conveyor belt 26 with several escalator steps 3 arranged one behind the other and which can be moved in a direction of movement 6 along a travel path by means of two conveyor chains 5 (only one visible in Figure 1) arranged in a closed ring and arranged parallel to one another. The double arrow of the direction of movement 6 indicates that the escalator 1 can transport passengers both from level E1 to level E2 and in the opposite direction. Each of the escalator steps 3 has a tread 21 and is attached to the two conveyor chains 5. In order to be able to move the conveyor chains 5, the escalator 1 has a drive area 13 in which a drive shaft 17, a gear 16, a drive motor 19, and a brake 18 are arranged.

[0042] The drive area 13 is usually located on the upper level E2 of the structure, while a tensioning station 7 (shown only schematically) with a deflection shaft 15 is located on the lower level E1. The drive shaft 17 and the deflection shaft 15, as well as other components of the escalator 1, are held in a supporting structure 2, usually in the form of a truss structure, which is shown only as an outline in Figure 1 for reasons of clarity. The escalator 1 also has two balustrades 8 (only one visible), each of which has a handrail 4 arranged circumferentially.

[0043] During an upward movement direction 6, the escalator steps 3 are moved in the forward direction from a lower access area 10 of the escalator 1 adjacent to the lower level E1, via a central inclined area 11, to an upper access area 12 adjacent to the upper level E1 and then moved back in the opposite direction during the return movement.

[0044] The drive motor 19 and the brake 18 arranged in the drive area 13 are controlled and regulated by a controller 14. The torque or the rotational movement of the motor shaft (covered by the gear box) of the drive motor 19 is transmitted to the drive shaft 17 via the gear box 16 (shown as an example is a worm gear and a drive chain). Since two conveyor chains 5 are usually present, between which the escalator steps 3 are arranged, the drive shaft 17 must also have two drive sprockets (not shown in detail), over which the conveyor belt 26 is guided in a motion-transmitting manner. All components of the drive area 13 are also housed in the supporting structure 2 and are spanned by a walkable floor cover 9, which is a component of the upper access area 12 (see also Figure 2).

[0045] Between the movable conveyor belt 26 and the stationary floor cover is a comb plate area 27, the combs 28 of which (see Figures 2 to 6) are among the wearing materials of the escalator 1 and are therefore replaceable. The combs 28 have comb teeth 29 that mesh with a web / groove structure 30, 31 formed on the tread 21 of the steps 3. Since the comb plate area 27 is one of the most critical areas of an escalator 1 or a moving walkway with regard to potential injury risks for passengers, there are regulations in relevant standards such as EN 115-2 that must be strictly adhered to. These regulations concern, for example, the condition of the combs 28 and the maximum permissible height h of the comb gap 33, as shown in Figure 3. Accordingly, the comb plate area 27 must be periodically inspected and, if necessary, maintained.

[0046] As mentioned in the introduction, an inspection method 45 according to the invention is intended to significantly simplify inspection. Figure 1 therefore also shows an inspection device 40 for carrying out the inspection method 45. In addition, further peripheral devices such as a cloud 90, a provisioning device 91, and a central monitoring device 92 are shown, which can be used to carry out further method steps Sn (see Figure 2; "n" of the reference symbol denotes an indefinite number of method steps) of the inspection method 45.

[0047] Since reference is made to Figures 2 to 5 to describe the inspection method 45, these will be described together below.

[0048] Figure 2 shows a three-dimensional partial view of the upper access area 12 shown in Figure 1. The two balustrades 8 with their balustrade bases 20 are arranged on both sides of the conveyor belt 26 (only one is visible). The internal structure (not visible) of the balustrade base 20 is covered with a cladding sheet 22 and a base sheet 23.

[0049] A smartphone is directed toward the access area 12, containing a software application 44 that transforms the smartphone into a mobile inspection device 40. The mobile inspection device 40 essentially comprises a user interface 41 (touchscreen), a digital storage medium 42, a processor 43, an imaging depth sensor 46, and the software application 44 stored at least temporarily in the storage medium 42. The inspection method 45 implemented in the software application 44 comprises the method steps S0 to Ss required for the inspection and the subsequent method steps Sn. Of course, the mobile inspection device 40 can also be a tablet or a laptop, or a device manufactured specifically for this purpose and containing at least the aforementioned components.

[0050] Figure 3 shows a cross-section through the comb plate area 27 shown in Figure 2, with only the structures of the two balustrade bases 20, the conveyor belt 26, and the combs 28 that are essential for inspection being drawn schematically. The contours shown with solid lines can be imaged by the imaging depth sensor 46; the contours of the conveyor belt 26 shown with dashed lines cannot be detected by the depth sensor 46. The tread surface 21 of the conveyor belt 26 is structured by webs 31 and grooves 30 that extend parallel to the intended direction of movement 6. The comb teeth 29 of the combs 28 engage in the grooves 30 of the conveyor belt 26 without contact, so that the step gap 33 extends in a meandering manner between the comb undersides 34 of the combs 28 and the tread surface 21 of the conveyor belt 26 from one base plate 23 to the other base plate 23.The underside 34 of the combs 28, shown with a dot-dash line, cannot be detected by the depth sensor 46 either.

[0051] Figure 4 shows a plan view of a section of the comb plate area 27 shown in Figures 2 and 3. The combs 28 arranged next to one another and the webs 31 and grooves 30 of the conveyor belt 26 or the steps 3 are clearly visible.

[0052] Figure 5 shows a flow chart of the inspection method 45 with the method steps So to Ss. By means of an input So via the user interface 41, the processor 43 is caused to process the method steps Si to Ss.

[0053] In process step Si, the imaging depth sensor 46 of the mobile inspection device 40 captures a 3D image 51 of all combs 28 and the adjacent surface areas of the base plates 23 and the conveyor belt 26. This can be done, as indicated in Figure 2, by capturing a single 3D image 73. A 3D image 51 as a digital 3D film sequence 70 of the comb plate area 27 is significantly more precise, but more complex in subsequent processing, in that the imaging depth sensor 46 is moved transversely to the transport direction 6 across the entire comb plate area 27 from one base plate 23 to the other base plate 23, as shown in Figure 3 by the double-dotted arrow 52.

[0054] Basically, the depth sensor 46 provides a 3D image 51 with a three-dimensional 1:1 image of the comb plate area 27 due to the distance detection for each pixel. However, the 3D images 73 are only sufficiently precise if the imaging depth sensor 46 is arranged stationary relative to the comb plate area 27 during the acquisition. Since the inspection device 46 should be as mobile as possible, depending on the imaging depth sensor 46 used, distortion correction and scaling of the 3D image 51 can hardly be avoided. In method step S2, a rectified and scaled 3D surface image 53 of the comb plate area 27 is therefore extracted from the 3D image 51. This includes at least the optically detectable surfaces of all combs 28 of the comb plate area 27, of the base plates 23 laterally adjacent to the combs 28 and of a tread surface 21 of the conveyor belt 26 located in the comb plate area 27.The 3D surface image 53 is essentially a digital 3D surface model, preferably at a scale of 1:1, which contains only the surfaces captured in the 3D recording 51. During extraction, the 3D image 73 of the 3D recording 51 or each frame 71 of the 3D film sequence 70 (see Figure 3) is rectified and scaled to a scale of 1:1.

[0055] Conversion parameters for rectification and scaling depend on the spatial position of the imaging depth sensor 46 relative to the comb plate area 27 at the time of each captured pixel. Particularly helpful is the detection and definition of fixed fixed points 81, 82, such as a fixed, prominent corner of a comb 28 (see Figures 2 and 4). Since the actual distances between two fixed points 81, 82, such as the comb length LK, are known and stored in the storage medium 42, the corresponding conversion parameters can be determined for each captured pixel of the 3D image 51. This is also possible via distance measurements VI, V2, as well as by measuring the associated angles α.If the software application 44 is implemented in a mobile device (smartphone, tablet), the spatial position of the imaging depth sensor 46 can be determined for each pixel of the 3D image 51, optionally also using position data from the built-in, three-axis position sensor 48 (see Figure 2). Using these conversion parameters and known processing algorithms used in image processing programs for rectifying and rescaling three-dimensional digital images, the 3D surface image 53 can be generated. Extraction can also involve converting the graphic format, for example, from a "pixel cloud" recorded in the 3D image 73 or frame 71 into a more processable format, such as a 3D vector graphic.

[0056] In the case of a 3D film sequence 70, the spatial position of the imaging depth sensor 46 can be determined analogously to the image frequency (i.e., for each frame 71 of the 3D film sequence 70). As already described above, this can also be done by distance measurements VI, V2, as well as by measuring the associated angles α, so that rectification and scaling can be carried out continuously, i.e., for each frame 71. The detection of fixed points 81, 82 in each frame 71 of the 3D film sequence 70 also helps to assemble the extracted, rectified, and scaled image sections of the 3D surface image 53 like a puzzle to form the 3D surface image 53. The detection of the fixed points 81, 82 and the distance LK between them is done by the imaging depth sensor 46 and using suitable analysis algorithms.

[0057] These analysis algorithms are based, for example, on known image processing techniques that are optimized and applied in self-learning processes using artificial intelligence in neural networks. In the self-learning process, for example, 3D images of a comb 28 taken from a wide variety of viewing directions are used, and the same fixed points 81, 82 are always marked and saved via a user interface until the analysis algorithms have access to a sufficient database to accurately identify the fixed points 81, 82. Another common image processing technique for generating information from a frame 71 or 3D image 73 is, for example, the calculation of the histogram, which provides information about the statistical brightness distribution in the 3D image 73 or frame 71.Such a histogram can, for example, serve as a configuration for further image processing steps or as information for a human user of the software application 44 by identifying and defining recognized outlines, edges, corners and joints in the 3D surface image 53 as fixed points 81, 82.

[0058] Further calculable information of a 3D image 73 includes, for example, its entropy or average brightness. Based on this information, vector analyses can be performed on 3D images 73 and frames 71 of digital 3D film sequences 70 to determine how individual fixed points 81, 82 shift relative to one another. From this, conclusions can be drawn about the current spatial focal point of the imaging depth sensor 46 in order to obtain suitable conversion parameters for rectifying, scaling, and merging the partial sections of the comb plate area 27 recorded on the individual frames 71, and for merging these partial sections into the 3D surface image 53.Of course, instead of the method described above, other analysis techniques and methods known from the technical field of image processing and video surveillance can also be used, for example, to extract the contours of the combs 28 or, as described further below, to measure side gaps S1B, S2B. In method step S3, a virtual 3D model 55 of the comb plate area 27 is retrieved from a digital storage medium 42, 54. The storage medium 42 can be part of the inspection device 40 (see Figure 2). However, a storage medium 54 can also be present outside the inspection device 40, for example as storage space in a server 56 that is part of the cloud 90 (see Figure 1). The cloud 90 can be accessed, for example, via a network node 93 of the Internet and via a communication module 49 of the inspection device 40.The virtual 3D model 55 has at least 3D comb models 28' of all combs 28 of the comb plate area 27 in a predetermined arrangement.

[0059] Since there are a large number of differently designed escalators and moving walkways, there are also a large number of differently designed comb plate areas 27 and thus also a large number of selectable 3D models 55. To find the correct 3D model 55, the 3D surface image 53 can, for example, be analyzed by an analysis module 95 (see Figure 2). The analysis algorithms described above can be used again here. Based on this analysis data, a suitable 3D model 55 can be retrieved from a model database 57 stored in the digital storage medium 42, 54.

[0060] Alternatively, the inspection device 40 can also scan a barcode or QR code 58 (see Figure 2) attached to the escalator 1 or moving walkway to be inspected. The 3D model 55 associated with the barcode or QR code 58 can then be retrieved from the model database 57.

[0061] Another possibility is for the mobile inspection device 40 to query an identification number ID from a controller 14 of the escalator 1 or moving walkway. Based on this identification number ID, an associated 3D model 55 is retrieved from the model database 57.

[0062] In process step S4, the 3D surface image 53 and the 3D model 55 are spatially combined. In other words, the 3D model 55 is inserted at the correct location in the 3D surface image 53. The individual combs 28 have such a small footprint that they are easily mapped completely on the 3D image 51 and thus also in the 3D surface image 53. Accordingly, their component boundaries, as comb edges 86 and joints 85, are sufficiently present on the 3D surface image 53 to be used as fixed points 81, 82 for this process step. Fastening screws 87 and corners 88 of the combs 28 can also be defined as fixed points 81, 82 (see Figure 4). The spatial alignment and correctly positioned insertion of the virtual 3D model 55 into the 3D surface image 53 can be carried out based on the spatial position of these ridge edges 86 and joints 85.The image recognition and image processing algorithms required for this have already been mentioned above. The joining process now produces an analyzable 3D model 59 of the comb plate area 27, which includes all relevant comb edges 86, joints 85, corners 88, and fastening screws 87. The cross-section shown in Figure 3 roughly corresponds to a cross-section through the analyzable 3D model 59, since the virtual 3D model 55 is also shown in this figure for better understanding.

[0063] In process step S5, a height h of the comb gap 33 is determined, which extends in a meandering shape between the tread surface 21 and the surface 61 of the comb underside 34 of the virtual 3D model 55. The determination of the height h is a simple query of the distance (difference in height) between superimposed points of these two surfaces 21, 61 and can be performed at several locations predefined in the software application 44 or in the virtual 3D model 55. If a query is performed at several locations, an average height h calculated from these, the smallest value for the height h, or the largest value for the height h can be used for further assessment. It should also be noted that the tread surface 21 with its grooves 30 and webs 31 must be virtually extrapolated (stretched) in the transport direction 6 below the comb underside 34 so that superimposed points are created.

[0064] In method step S5, a minimum side gap width S1Bmin, S2Bmin and a maximum side gap width S1Bmax, S2Bmax between the tread surface 21 and the adjacent base plate 23 are measured from the rectified and scaled 3D surface image 53 on both sides of the tread surface 21. From the minimum side gap width S1Bmin, S2Bmm and the maximum side gap width S1Bmax, S2Bmax, an inclination angle β of the tread surface 21 to the base plate 23 can be determined (see Figure 4). Furthermore, in method step S5, a contour comparison 62 of the comb teeth 29 of all combs 28 is carried out between the 3D surface image 53 and the 3D model 55. The contour comparison 62 is shown in particular in Figure 6. The contour comparison 62 is carried out, for example, by an area comparison 62A and / or by a deviation of the recognized outline lines 62B.Deviations in the detected contour lines 62B indicate an inadmissible deviation with regard to the tooth shape of a comb tooth 29, differences in the area comparison 62A indicate missing comb teeth 29. The image recognition and image processing algorithms required for this have already been mentioned above.

[0065] In process step Se, the height h of the comb gap 33 is compared with the limit values ​​h min, hmax retrieved from the digital storage medium 42, 54. As soon as the height h is outside these limit values ​​h min, hmax, the inspection device outputs a first warning signal Hsi. Furthermore, the measured side gap widths SiBmax, S2Bmax, SiBmin, S2Bmm are compared with the limit values ​​Gimm, Gimax G?™ , G max retrieved from the digital storage medium 42, 54, and a second warning signal Hs2 is output if the side gap widths SiBmax, S2Bmax, SiBmin, S2Bmin are outside these limit values ​​Gimm, Gima. The second warning signal HS2 is also output if the sum of the side gap widths exceeds a limit value Gs corresponding to SiBmax, S2Bmax, SiBmin, S2Bmm um exceeds.

[0066] If the calculated inclination angle ß exceeds a limit value ß retrieved from the digital storage medium 42, 54 ma x, a third warning signal Hss is output by the inspection device 40. An excessively large inclination angle ß indicates asymmetrical wear of the conveyor chains 5 of the conveyor belt 26 and / or a deformation of the base plate 23 in this area. A fourth warning signal Hs4 is output if there is an impermissible deviation with regard to one or more tooth shapes (deviation of the contour lines 62B) of the comb teeth 29 and / or comb teeth 29 are missing (deviations in the area comparison 62A).

[0067] In process step S7, the detected deviations are displayed on the user interface 41 of the inspection device 40 based on the issued warning signals, and appropriate, further process steps Sn are suggested. If a third - TI -

[0068] If the information signal Hss is output by the inspection device 40, the inspection device 40 indicates to the service technician as a further process step Sn, for example, that he must check the base plates 23 for deformations and, if these are OK, that the conveyor chains 5 of the conveyor belt 26 must be replaced.

[0069] To facilitate the service technician's work, if a fourth warning signal Hs4 is present, the combs 29 affected by the deviations that need to be replaced can be marked with a marker 99 on the 3D surface image 53 of the comb plate area 27 (see Figure 6). The 3D surface image 53 provided with markers 99 is displayed on the user interface 41 of the mobile inspection device 40.

[0070] Based on the fourth indication signal Hs4, the component identification numbers 98 of the combs 28 to be replaced that are affected by the deviations can also be displayed by the inspection device 40. Furthermore, the component identification number 98 can also be sent to the provisioning device 91 shown in Figure 1. The provisioning device 91 checks the inventory, reports a date to the mobile inspection device 40 indicating when and where the requested components will be available, and provides the requested components according to the transmitted component identification numbers 98.

[0071] If the inspection device 40 has generated one of the warning signals Hsi to Hs4, the inspection device 40 can place the control system 14 of the escalator 1 or the moving walkway into a maintenance mode based on one or more of these events. This maintenance mode can be activated depending on the weighting of the warning signals Hsi to Hs4 for operational safety and the magnitude of the detected deviation from the limit specifications h The highest level means that the detected defects are so serious that ferry service on escalator 1 or the moving walkway is blocked until repairs are made. A medium level, for example, can define a time window during which ferry service at nominal speed or ferry service at reduced speed is still possible. A lower level, for example, can stipulate that ferry service is not affected, but rather that the service technician is simply requested to schedule a maintenance appointment to carry out the repairs.

[0072] To enable the inspection device 40 to exchange data with the peripheral devices 90, 91, 92 shown in Figure 1 and / or the controller 14, it has a communications module 49. This can communicate with the peripheral devices 90, 91, 92 or the controller 14 via a wired or wireless connection, using any suitable data transmission technology such as Bluetooth, Ethernet, etc. The inspection method 45 ends with method step Ss, in which the service technician confirms the execution and any resulting actions by entering data via the user interface 41.

[0073] Although an escalator is shown in Figure 1, it is obvious that the inspection device 40 and the associated inspection method 45 can also be used for moving walks.

[0074] Finally, it should be noted that terms such as "having," "comprising," etc., do not exclude other elements or steps, and terms such as "a" or "an" do not exclude a plurality. Furthermore, it should be noted that features or steps described with reference to one of the above embodiments may also be used in combination with other features or steps of other embodiments described above. Reference signs in the claims are not to be considered as limitations.

Claims

Patent claims 1. Inspection method (45) for the comb plate area (27) of an escalator (1) or a moving walkway by means of a mobile inspection device (40), comprising the following steps: • Capturing (Si) a 3D image (53) of all combs (28) and the surface areas (21, 23) adjacent to them of a comb plate area (27) of the escalator (1) or the moving walkway with an imaging depth sensor (46) of the mobile inspection device (40); • Extracting (S2) a scaled and rectified 3D surface image (53) of the comb plate area (27) from the 3D image (53); at least of all combs (28) of the comb plate area (27), of the surface areas of the base plates (23) of the comb plate area (27) laterally adjacent to the combs (28), and of a tread surface (21) of a conveyor belt (26) of the escalator (1) or the moving walkway located in the comb plate area (27); • calling (S3) a virtual 3D model (55) of the comb plate area (27) from a digital storage medium (42, 54), wherein the virtual 3D model (55) has at least 3D comb models (28') of all combs (28) of the comb plate area (27) in a predetermined arrangement; • spatial merging (S4) of the 3D surface image (53) and the virtual 3D model (55); • Determining (S5) a height (h) of a comb gap (33) between the tread surface (21) and a surface (61) of the comb underside 34 of the virtual 3D model (55); and • Comparison (Se) with limit specifications (h) retrieved from the digital storage medium (42, 54) m m, h max ) for the height (h) of the comb gap (33) and outputting a first indication signal (Hsi) if the determined height (h) deviates from the limit specifications (h m m, h max ) differs.

2. Inspection method (45) according to claim 1, wherein a minimum side gap width (SiBmin, S2Bmm) and a maximum side gap width (SiB max , S2B max ) between the tread (21) and the adjacent base plate (23) is measured, and wherein the maximum side gap widths (SiBmax, S2Bmax) are compared with limit specifications (Gimm, Gl max G2min, G2max, Gsum) retrieved from the digital storage medium (42, 54), and a second indication signal (Hs2) is output if one of the limit specifications (Gimm, Gl max G2min, G2max, Gsum) is exceeded.

3. Inspection method (45) according to claim 2, wherein an inclination angle (ß) of the tread surface (21) to the base plate (23) is determined from the minimum side gap width (SiBmin, S2Bmm) and the maximum side gap width (SiBmax, S2Bmax), and the inclination angle (ß) is compared with limit specifications (ß ma x) for the inclination angle (ß) and a third indication signal (Hss) is output if the determined inclination angle (ß) deviates from the limit specifications (ßmax).

4. Inspection method (45) according to one of claims 1 to 3, wherein the 3D recording (53) is a digital film sequence (70) of the comb plate region (27) from the first base plate (23) to the opposite, second base plate (23), wherein to generate the 3D surface image (53) prominent fixed points (81, 82) are defined in the frames (71) of the digital film sequence (70) and used to extract the 3D surface image (53).

5. Inspection method (45) according to claim 4, wherein a prominent fixed point (81, 82) is a comb edge (86), a fastening screw (87) of the comb (28), a joint (85) between two combs (28) or a corner (88) of the comb (28).

6. Inspection method (45) according to one of claims 1 to 5, wherein the 3D surface image (53) is analyzed by an analysis module (95) and, based on its analysis data, a suitable virtual 3D model (55) is retrieved from a model database (57) which is stored in a digital storage medium (42, 54).

7. Inspection method (45) according to one of claims 1 to 5, wherein after scanning a barcode or QR code (58) which is attached to the escalator (1) to be inspected or to the moving walkway to be inspected, a virtual 3D model (55) associated with the barcode or QR code (58) is retrieved from a model database (57) is retrieved, which is stored in a digital storage medium (42, 54).

8. Inspection method (45) according to one of claims 1 to 5, wherein the mobile inspection device (40) queries an identification number (ID) from a controller (14) of the escalator (1) or the moving walkway and a virtual 3D model (55) associated with the identification number (ID) is called up from a model database (57) which is stored in a digital storage medium (42, 54).

9. Inspection method (45) according to one of claims 1 to 8, wherein a contour comparison (62) of all combs (28) between the 3D surface image (53) and the virtual 3D model (55) is carried out by the mobile inspection device (40) by checking differences from the contour comparison (62B) for an inadmissible deviation with regard to the tooth shapes of the combs (28) and / or the combs (28) are checked by a surface comparison (62A) with regard to missing comb teeth (29) and a fourth indication signal (Hs4) is output if there is an inadmissible deviation with regard to the tooth shapes of the comb teeth (29) and / or comb teeth (29) are missing.

10. Inspection method (45) according to claim 9, wherein, in the presence of a fourth indication signal (Hs4), the components to be replaced that are affected by the deviations are marked on the 3D surface image (53) of the comb plate region (27) and the 3D surface image (53) provided with a marking (99) is displayed on a user interface (41) of the mobile inspection device (40).

11. Inspection method (45) according to claim 9 or 10, wherein, based on the fourth indication signal (Hs4), component identification numbers (98) of the components to be replaced that are affected by the deviations are displayed by the inspection device (40) and / or sent to a provision device (91).

12. Inspection method (45) according to one of claims 1 to 11, wherein the inspection device (40) puts a control (14) of the escalator (1) or the moving walkway into a maintenance mode when at least one of the indication signals (Hsi to HS4) is present.

13. A mobile inspection device (40) comprising a user interface (41), a digital storage medium (42, 54), a processor (43), an imaging depth sensor (46), and a software application (44) at least temporarily stored in the storage medium (42, 54) with the respectively required method steps (Si,... Sn) of the inspection method (45) according to one of claims 1 to 12, wherein the method steps (Si,... Sn) of the inspection method (45) are processed by the processor (43) upon initiation of an input via the user interface (41).

14. A mobile inspection device (40) according to claim 13, wherein said Communication module (49) which can be connected to a communication module of at least one of the following devices for the purpose of exchanging data as required: a controller (14) of an escalator (1) or a moving walkway, a central monitoring device (92), a provision device (91) for spare parts, a network node (93) of the Internet.

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