Method for measuring the braking distance of an escalator or a moving walkway

Abstract

The invention relates to a method for measuring the braking distance (LB) and to a braking distance measuring device (30) for carrying out the method on an escalator (1) or a moving walkway. The braking distance measuring device (30) has at least one trigger device (45) which can be connected to the controller (14) of the escalator (1) or the moving walkway, an optically detectable linear measuring scale (31), an optical sensor (35), and an acoustic sensor (36). In order to allow a more precise measurement of the braking distance (LB), a braking process is optically and acoustically recorded as an image sequence (60) with a graphically displayed audio track (65). The start point (68) and the end position (69) of braking operation noises (51) recorded on the audio track (65) can be precisely assigned to the images (62, 63) of the image sequence (60), and the braking distance (LB) is ascertained from the determined images (62, 63) by comparing the different positions of a marking (53) with the measuring scale (31).

Description

[0001] The invention relates to a method for measuring the braking distance of an escalator or moving walkway, a braking distance measuring device for carrying out this method, and an escalator or moving walkway with such a braking distance measuring device.

[0002] Escalators and moving walkways are used to transport people and are found in department stores, shopping malls, train stations, airports, and similar locations. They feature a conveyor belt that is mounted around the perimeter of the escalator or moving walkway and can be driven by a motor. Because these systems transport people, they are subject to stringent safety requirements, such as those defined in the European standard EN115-1 or the US standard ASME A17.1 / CSA B44.

[0003] One of these safety regulations concerns the permissible braking distance of the conveyor belt. The braking distance inevitably occurs due to the inertia of the moving parts after the drive motor is disconnected from the power supply and a service brake or safety brake (hereinafter referred to simply as the brake) of the escalator or moving walkway is activated. Most authorities require the operators or the companies entrusted with the maintenance of these systems to periodically check the braking distance and service the brake if the braking performance does not meet the applicable standards. To prevent falls by users, the brake must also not engage too forcefully. Therefore, the standards also specify a maximum permissible deceleration during braking. For example, EN 115-1 specifies a maximum permissible deceleration for escalators and moving walkways at a given nominal speed of 0.75m / s (operating speed) provides a standard braking distance of the conveyor belt in the range between 0.4m and 1.5m, whereby the maximum permissible deceleration of 1m / s² must not be exceeded.

[0004] To measure the standard braking distance of the conveyor belt, JP2008265971A proposes a braking distance measuring device and a method for performing this measurement. A linear measuring scale is attached to the conveyor belt, and an optical sensor is temporarily attached to a fixed part of the escalator or moving walkway and connected to the escalator's control system. The conveyor belt is then brought up to operating speed. As soon as the optical sensor detects the leading end of the measuring scale, a stop signal is sent to the control system, and the conveyor belt is braked. The distance traveled by the optical sensor on the measuring scale corresponds to the standard braking distance. This measurement method thus fully complies with the standard EN115-1, which stipulates that the braking distance must be measured from the occurrence of the stop signal until the conveyor belt comes to a complete stop.Furthermore, the standard recommends keeping the standard braking distance as close as possible to the lower limit of the range (0.4m in the example).

[0005] The braking distance measurement method described above has the disadvantage that it also records periods without braking torque, such as the reaction times of the optical sensor, the control unit, and the electromechanical switches (contactor or relay) controlled by the control unit, as well as the brake's reaction time from the interruption of the ventilation current until the braking torque begins to act. Therefore, the described braking distance measurement method does not provide results that accurately reflect the actual braking behavior of the brake (braking distance while the braking torque is acting).

[0006] The object of the present invention is to provide a braking distance measurement method which delivers more precise measurement results regarding the actual braking behavior of the brake.

[0007] This task is solved by the following procedure for measuring the braking distance of an escalator or moving walkway, and with a braking distance measuring device for carrying out this procedure.

[0008] The escalator or moving walkway on which such a measurement can be performed has a conveyor belt, at least one drive motor for powering the conveyor belt, a brake for decelerating the conveyor belt, and a control unit. The drive motor and the brake can be controlled by the control unit. The method for measuring the braking distance can be used with all known brake types of escalators and moving walkways. To carry out the method, a braking distance measuring device is arranged in the area of ​​the conveyor belt, which includes at least one triggering device connectable to the control unit, an optically detectable linear measuring scale, and an optical sensor.

[0009] The procedure for measuring the braking distance comprises several steps, which can be carried out in the following order. However, this order is not mandatory; where appropriate, steps can be performed before or after others, or further steps, as described in the following paragraphs, can be inserted between these steps.

[0010] In one process step, the linear measuring scale is positioned in the escalator or moving walkway such that, as a result of the conveyor belt's movement, it exhibits a relative motion to a marker. This relative motion can be captured by the optical sensor, for example, as an image sequence. As explained below, there are various ways to position a measuring scale and define or arrange a marker.

[0011] In a further process step, the conveyor belt is accelerated to a predetermined speed. This predetermined speed typically corresponds to the normal operating speed, usually referred to as the rated speed. The predetermined speed can also be faster or slower than the rated speed if different operating conditions of the service brake are to be tested. Once the predetermined speed is reached, a stop signal is sent to the control unit via the release mechanism. This stop signal can be triggered manually, for example, by entering a command into the release mechanism. Alternatively, the stop signal can be generated automatically by the release mechanism, for example, by having the predefined speed trigger the stop signal in the release mechanism.

[0012] In a further process step, the optical sensor records the relative motion sequence at least from the stop signal until the conveyor belt comes to a complete standstill. The braking distance measuring device also includes an acoustic sensor that records the brake operating noises synchronously with the optical recording. These brake operating noises represent the actual braking action in chronological order. Since the recording of the relative motion sequence was synchronous, the beginning of the brake operating noises can be clearly assigned to a specific frame of the relative motion sequence captured as an image sequence. To determine the braking distance, a subsequent frame from the captured image sequence of the motion sequence must be selected, one that was clearly captured at a point in time when no brake operating noises were present.By comparing the two images, the braking distance traveled during actual use of the brakes can be determined from the different positions of the marker relative to the measuring scale.

[0013] The braking distance measured in this way allows, for example, a more precise calculation of the average deceleration of the brakes. It is also possible to record a braking curve (distance / time diagram, where time is defined by the number of frames per second) by evaluating the braking distance step by step from frame to frame, from which the maximum deceleration can be read. Based on these measurement results, the brakes can be adjusted to near the maximum permissible deceleration. This minimizes the actual braking distance without exceeding the defined maximum deceleration value.

[0014] Measuring the braking distance during actual brake application also offers advantages for diagnosing the technical condition of escalators or moving walkways. For example, the condition of the brake pads and / or their changes compared to previous measurements can be assessed more precisely. Furthermore, the triggering point of the stop signal can also be recorded, allowing it to be associated with a corresponding image in the recorded sequence. If the optical recording of the motion sequence begins with the stop signal, this is logically the first image. The reaction time of the braking system until the actual application of braking torque, and the distance traveled during this process, can then be determined by comparing the two recording times: this first image and the image at the beginning of the braking noise.The distance traveled by the marker, hereinafter referred to as the reaction length, can also be determined using these two images. A reaction time or reaction length that is too long compared to expected values ​​may indicate that, for example, the contactors mentioned above need to be replaced. As mentioned at the beginning, the EN115-1 standard stipulates that the braking distance measurement must be taken from the moment the stop signal is triggered until the conveyor belt has come to a complete stop. This standard braking distance can be determined by simply adding the reaction length and the braking distance.

[0015] As described above, this evaluation can be performed manually throughout, but this is time-consuming. Therefore, in a further development of the method, the recording of the relative motion and the recording of the synchronously recorded brake operating noises are displayed as a graphically represented audio track in parallel within an image sequence. This makes it much easier to identify the two or three relevant images within an image sequence, as previously described, since the images no longer need to be first assigned based on the temporal sequence of the brake operating noises by reading out the recording times.

[0016] From the image sequence, a starting position of the marker relative to the measuring scale is extracted using a starting point of the brake operating noise. Furthermore, an end position of the marker relative to the measuring scale is also extracted from the cessation of the brake operating noise. The image containing the end position can also be defined by a fixed end position at which no brake operating noise is present, since once the conveyor belt has come to a standstill, no brake operating noise is present and all subsequently recorded images in the image sequence look exactly the same.

[0017] In a further development of the invention, the starting and ending positions are determined automatically from the graphically represented brake operating noise or the audio track using an image processing program. This program employs known image analysis methods and algorithms from the electronic processing of video sequences. These algorithms are based, for example, on established image processing techniques that are optimized and applied in self-learning processes using artificial intelligence in neural networks. A common image processing technique for generating information from an image is, for instance, the calculation of the histogram, which provides information about the statistical brightness distribution in the image.Such a histogram can serve, for example, as a configuration for further image processing steps or as information for a human user of software. Other calculable information about an image includes its entropy and average brightness. Based on this information, vector analyses can be performed to determine how individual distinctive points shift relative to each other, allowing conclusions to be drawn about movement scenarios of the marker relative to the measurement scale. Using the aforementioned methods, for example, an image analysis of the sound track optically represented in the image sequence can be performed, and the image containing the starting point of the brake noise, as well as one of the images in the sequence where the absence of the brake noise is clearly discernible, can be marked within the image sequence.Of course, an analysis of the noise level of the recorded brake operation noise can also be carried out, so that the time of the start and end of brake operation can be determined and the corresponding images from the image sequence can be identified via the temporal assignment.

[0018] In a further automation step of the present process, the distance between the starting position and the end position is determined by comparing the two marked images in the image sequence. This distance corresponds to the braking distance covered during braking. The different positions of the marker relative to the measuring scale can be read, for example, by optical character recognition (OCR) of numbers plotted on the measuring scale and subsequent difference calculation.

[0019] In one embodiment of the invention, the triggering device is connected to the control unit. Here, the triggering device receives operating data of the drive motor from the control unit, and a stop signal is sent to the control unit as soon as the drive motor reaches a speed that corresponds to the predetermined speed of the conveyor belt.

[0020] In a further embodiment of the invention, the stop signal can be manually entered into the triggering device, for example, by pressing a push button or via a keypad on the triggering device. Once the stop signal has been entered, it is immediately transmitted from the triggering device to the controller. Additional commands can be transmitted to the controller via the keypad, which can also be generated on a touchscreen of the triggering device. For example, the start command can be entered via the keypad so that the controller sets the conveyor belt in motion. Furthermore, the conveying direction or the direction of movement of the conveyor belt can also be entered via the keypad.It is also possible for the control system to transmit operating data from the passenger transport system, such as the current speed, to the release device, which can then be displayed on the screen. The control system can also transmit safety-related messages to the release device, so that, for example, a refusal of the start command and the underlying cause can be displayed on its screen.

[0021] In summary, the braking distance measuring device for carrying out the aforementioned method comprises at least one triggering device connectable to the controller, an optically detectable linear measuring scale, an optical sensor, and an acoustic sensor. The optical sensor, the acoustic sensor, and the triggering device are preferably integrated into a smartphone or tablet with a software application (computer program). The software application includes at least program steps that enable the synchronous recording of the relative movement of the arranged or defined marker to the measuring scale and the braking noises. The software application may also contain program components by means of which the image processing described above can be performed. Furthermore, a wired or wireless connection to the controller of an escalator or moving walkway can be temporarily established.

[0022] Preferably, the braking distance measuring device comprises a holder for the smartphone or tablet, wherein this holder can be temporarily arranged on a fixed part of an escalator or moving walkway. This fixed part can be, for example, a balustrade or balustrade base or a floor covering of the escalator or moving walkway.

[0023] To ensure high-quality recording of braking noise, at least the linear measuring scale, the optical sensor, and the acoustic sensor of the braking distance measuring device are preferably located in the drive area of ​​the escalator or moving walkway. In the case of an escalator, the drive area is typically located in the upper access area so that primarily tensile forces act on the conveyor belt. The drive motor, a drive shaft, a gearbox, and the brake are usually located in the drive area beneath a walkable floor covering. This walkable floor covering allows access to and from the escalator. Moving walkways are designed in a similar manner.

[0024] As mentioned above, there are various options for arranging the linear measuring scale and, if applicable, the marking. The linear measuring scale preferably has a slat-shaped support with a metric length scale and / or a length scale in inches. The marking can be an existing contour of the escalator or moving walkway, but also a temporarily affixed object such as a sticker, a colored dot, etc.

[0025] InIn a first variant, the marking is positioned or defined on the conveyor belt, and the linear measuring scale is located on a fixed part of the escalator or moving walkway. To simplify handling for the person responsible for the measurement, the marking is preferably defined. For example, the marking could be a gap between two escalator steps or a gap between two pallets on the moving walkway conveyor belt. Of course, a marking that can be temporarily attached to the conveyor belt can also be used, such as a line drawn with a waterproof marker that extends perpendicular to the direction of travel of the conveyor belt.

[0026] In a second variant, the measuring scale is positioned on the conveyor belt, and the marking is defined or located on a fixed part of the escalator or moving walkway. For example, the marking could be a metal joint between two cladding panels of a balustrade on the escalator or moving walkway.

[0027] Of course, a marking that can be temporarily attached to the balustrade can also be used, for example an arrow-shaped sticker.

[0028] 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 are designated by the same reference numeral. They show: Figure 1: Schematic, cutaway side view of an escalator and its main components; Figure 2: Three-dimensional partial view of the escalator. Figure 1 designated drive area with a braking distance measuring device; Figure 3: three-dimensional view of a smartphone with a software application by which the smartphone can be used as a component of the braking distance measuring device; Figure 4: an image from an image sequence taken by an optical sensor of the Figure 2Figure 5A: a first image from an image sequence recorded by the braking distance measuring device at the time of input of a stop signal; Figure 5B: a second image from the same image sequence at the time of a starting point at which parallel recorded brake operating noises begin; and Figure 5C: a third image from the same image sequence at the time of an end position at which parallel recorded brake operating noises end.

[0029] The Figure 1 Figure 1 schematically shows a cutaway side view of an escalator 1 and its main components. The escalator 1 can be used, for example, to transport people between two levels E1 and E2 of a building.

[0030] The escalator 1 has a conveyor belt 26 with several escalator steps 3 arranged one behind the other and which are moved by means of two ring-shaped closed and parallel conveyor chains 5 (in Figure 1 (only one visible) can be moved in a direction of movement 6 along a travel path. The double arrow indicating the direction of movement 6 shows that the escalator 1 can transport users both from level E1 to level E2 and in the opposite direction. Each escalator step 3 is attached to the two conveyor chains 5 between them. To move the conveyor chains 5, the escalator 1 has a drive section 13 in which a drive shaft 17, a gearbox 16, a drive motor 19, and a brake 18 are arranged. The escalator 1 can have different types of brakes, for example, the one described in the Figure 1The service brake shown is usually designed as a drum brake or band brake. The escalator may also have a safety brake, as disclosed, for example, in WO2014 / 009227A1.

[0031] The drive section 13 is typically located on the upper level E2 of the structure, while a tensioning station 7 (shown only schematically) with a deflection axis 15 is located on the lower level E1. The drive shaft 17 and the deflection axis 15, as well as other load-bearing components of the escalator 1, are held in a supporting structure 2, usually in the form of a truss structure, which is Figure 1 For the sake of clarity, it is only shown as an outline. The escalator 1 also has two balustrades 8 (only one visible), each with a handrail 4 running around its perimeter.

[0032] The escalator steps 3 are moved during an upward movement direction 6 in the forward direction from a lower access area 10 of the escalator 1 adjacent to the lower level E1, via a middle inclined area 11, to an upper access area 12 adjacent to the upper level E1 and then moved back in the opposite direction in the return direction.

[0033] The drive motor 19 and the brake 18, located in the drive section 13, are controlled and regulated by a control unit 14. The torque or rotational movement of the motor shaft (concealed by the gearbox) of the drive motor 19 is transmitted via the gearbox 16 (a worm gear and a drive chain are shown as examples) to the drive shaft 17. Since there are usually two conveyor chains 5 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 to transmit motion. All components of the drive section 13 are also housed in the supporting structure 2 and are spanned by a walkable floor covering 9, which forms part of the upper access area 12.

[0034] Furthermore, a braking distance measuring device 30 for measuring the braking distance is arranged in the drive area 13 of the escalator 1. In the present embodiment, this braking distance measuring device 30 can be installed temporarily, meaning it can be installed, used, and removed as needed. However, a permanent installation of the braking distance measuring device 30 is also conceivable, for example, in a balustrade base 20 of the balustrade 8.

[0035] The Figure 2 shows a three-dimensional, enlarged partial view of the [device / thing] in the Figure 1 The designated drive area 13 includes a braking distance measuring device 30 installed there. The braking distance measuring device 30 has a linear measuring scale 31 and a smartphone 32 with an optical sensor 35 and an acoustic sensor 36 (see Figure 3The braking distance measuring device 30 also includes a holder 33 for the smartphone 32 and fastening means 34 for the linear measuring scale 31. In the present embodiment, the slat-shaped measuring scale 31 is placed with its first end 31A on the floor cover 9 and fixed to the floor cover 9 with the fastening means 34, which is shaped like a brick. The linear measuring scale 31 is arranged parallel to the direction of movement 6 in the drive area 13 with respect to its longitudinal extent. Its second end 31B projects beyond a comb plate 27, which serves as a transition between the floor cover 9 and the conveyor belt 26, and also extends beyond more than two escalator steps 3 of the conveyor belt 26. In the present embodiment, the holder 33 has a suction cup 37, which is fixed to a cladding plate 21 of the balustrade base 20.The smartphone 32 rests on the holder 33, the holder 33 being arranged on the cover plate 21 such that the optical sensor 35 of the smartphone 32 can detect both the linear measuring scale 31 and at least two escalator steps 3 of the conveyor belt 26. Since the brake 18 is located below the floor cover, the acoustic sensor 36 is also protected by this arrangement (see . Figure 3 ) of the smartphone 32 for recording brake operating noises 51 (see Figures 5A to 5C ) ideally positioned.

[0036] The Figure 3 Figure 3 shows a three-dimensional view of a smartphone 32 with a software application 38, which enables the smartphone 32 to be used as a component of the braking distance measuring device 30. Furthermore, in Figure 3 The components drive motor 19, brake 18 and control 14 of the escalator 1 are shown schematically to illustrate their interactions with the smartphone 32.

[0037] The use of a conventional smartphone 32 is therefore suitable because it has sufficient computing and storage capacity for storing and processing the software application 38 and features an optical sensor 35 (symbolically represented as a video camera), an acoustic sensor 36 (symbolically represented as a hand microphone), and a touch-sensitive screen 39 on which graphic buttons 41, 42, 43, 44, and thus manually operable elements of a triggering device 45, can be generated. Furthermore, the smartphone 32 has a communication module 47 through which a data connection to the escalator control unit 14 can be established. Since a tablet has the same components and properties, a tablet can also be used instead of the smartphone 32.Naturally, components of the same type, which are to be used instead of the smartphone 32 for the braking distance measuring device 30, can also be combined in a device specifically designed and built for the braking distance measuring device 30. It is even possible to arrange the aforementioned components separately from one another in the drive area 13, whereby a communication link 47 must be established, at least temporarily, between the triggering device 45, the optical sensor 35, the acoustic sensor 36, and, if applicable, the control unit 14. The triggering device 45 can be designed as a handheld device with a push button (not shown) to, for example, input a stop signal 46.

[0038] The aforementioned software application 38 for the smartphone 32 includes at least program steps which enable a synchronous recording of a relative movement of a marker 53, 54, 55 to the linear measuring scale 31 and the brake operating noises 51 of the brake 18 (see Figure 4 Further explanations regarding the linear measuring scale 31 and the mentioned markings 53, 54, 55 are provided below in the description. Figure 4 to find.

[0039] The software application 38 also includes program steps by which, following the procedure sequence, the required graphic buttons 41, 42, 43, 44 and / or graphical representations 48 of operating data can be generated on the screen 39. In the present embodiment, a first button 41 serves to control the escalator 1 (see also Figure 1) to move escalator 1 in a direction of travel 6 from the lower floor E1 to the upper floor E2. A second button 42 can move escalator 1 in a direction of travel 6 from the upper floor E2 to the lower floor E1.

[0040] In a central area of ​​the screen 39, a graphical representation 48 can be created and displayed by further program steps of the software application 38. The measurement data required for this are transmitted from the controller 14 via the communication module 47 to the smartphone 32, which serves as the trigger device 45. The graphical representation 48 of the exemplary embodiment shows the acceleration behavior of the conveyor belt 26 from standstill V0 to the nominal speed VN. As soon as the nominal speed VN is reached, a stop signal 46 can be entered via a third button 43 of the trigger device 45 and sent to the controller 14 of the escalator 1. With the input of the stop signal 46, the optical sensor 35 and the acoustic sensor 36 are simultaneously activated to record an image sequence 60 and an associated audio track 65 (see Figures 4 and 5A to 5C to record.

[0041] The stop signal 46 is immediately processed by the control unit 14, so that the drive motor 19 is disconnected from a power supply (not shown) and the brake 18 is activated by switching off a ventilation current. As soon as the brake shoes 18' of the brake 18 engage, a loud braking noise 51 is emitted, decreasing in volume, until the conveyor belt 26 (see Figure 1). At this point, it should be noted that the brake operating noises 51 of a service brake and a safety brake can differ, especially during the decay of the brake operating noise 51. However, all brake types have in common that the beginning of the brake operating noises 51 is very clearly recognizable on the sound track 65. As soon as the conveyor belt 26 has come to a stop, an evaluation of the measurement results and a determination of a braking distance LB from the measurement performed can be initiated by tapping a fourth button 44 of the triggering device 45. The determination of the braking distance LB is described below using the Figures 5A to 5C depicted.

[0042] The Figure 4 shows image 64 from an image sequence 60, which was taken by the optical sensor 35 of the in the Figures 1 and 2The braking distance measuring device 30 shown was recorded. The linear measuring scale 31, located above the escalator steps 3 of the conveyor belt 26, is clearly visible. Furthermore, the balustrade base 20 is partially visible, in particular two cladding plates 22, 23 of the balustrade base 20, as well as the floor cover 9 and the comb plate 27.

[0043] As mentioned above, the linear measuring scale 31 is arranged in the drive area 13, and a marking 53, 54 is defined or also arranged. In the arrangement actually shown in the image, a gap located between two escalator steps serves as marking 53, which moves relative to the stationary measuring scale 31 when the conveyor belt 26 is running. In other words, the gap is defined as marking 53. Alternatively, a special marking 54 can also be temporarily applied to the conveyor belt 26, for example, the arrow indicated by a broken line, which is preferably applied to one of the escalator steps 3 using a clearly visible color or as a sticker. It should also be noted that, in the case of a conveyor belt 26 of a moving walkway, the gap between two pallets can be defined as marking 53.Due to the very narrow design of pallets, it may be better to provide a temporarily attachable marking 54.

[0044] As indicated by the dashed line, the measuring scale 56 can, for example, also be arranged as a sticker on the conveyor belt 26. In this version, the marking 24, 55 is to be provided on a fixed part of the escalator 1 or the moving walkway. Marking 24 can, for example, be defined as a sheet metal joint between the two cladding panels 22, 23. In this alternative, marking 55 can also be an arrow-shaped sticker that can be temporarily attached to a fixed part of the escalator 1 or the moving walkway.

[0045] The procedure that can be carried out with the braking distance measuring device 30 described above is explained below using the following example. Figures 5A to 5C and with the aid of the Figures 2 and 3 explained. Here, the Figure 5A a first image 61 from an image sequence 60 recorded by the braking distance measuring device 30 at the time of input 67 of a stop signal 46. The Figure 5B A second image 62 from the same image sequence 60 is shown at a starting point 68, at which parallel recorded brake operating noises 51 begin. Figure 5C shows a third image 63 from the same image sequence 60 at the time of an end position 69, at which the parallel recorded brake operating noise 51 ends.

[0046] The procedure for measuring the braking distance LB of an escalator 1 or a moving walkway comprises, on the one hand, preparatory steps and, on the other hand, measurement and evaluation steps. The preparatory steps include the installation of a braking distance measuring device 30 in the drive area 13 above the conveyor belt 26. Possible configurations for this have already been described above. Figures 2 and 4has been described. Furthermore, the triggering device 45 of the braking distance measuring device 30 is connected to the control unit 14 of the escalator 1 via signal transmission.

[0047] The measurement steps include the procedural steps required to generate image sequences 60 and their corresponding audio tracks 65 with the braking noises 51. For example, a manual input at the trigger device 45 brings the conveyor belt 26 up to a predetermined speed VV, such as the nominal speed VN. After reaching the predetermined speed VV, a stop signal 46 is sent to the controller 14 via the trigger device 45. Alternatively, the trigger device 45 can receive operating data from the drive motor 19 from the controller 14 and automatically send a stop signal 46 to the controller 14 as soon as the drive motor 19 reaches a speed corresponding to the predetermined speed VV of the conveyor belt 26.

[0048] Upon input of the stop signal 46, the optical sensor 35 begins recording the relative motion sequence between the marker 53 and the linear measuring scale 31, at least from the stop signal 46 until the conveyor belt 26 comes to a standstill V 0. Simultaneously with the optical recording, the acoustic sensor 36 of the braking distance measuring device 30 records the audio track 65 containing the braking operating noises 51 of the brake 18.

[0049] As in the Figures 5A to 5C As shown, for easier and clearer evaluation, the recording of the relative movement between the marker 53 and the linear measuring scale 31 and the recording of the synchronously recorded sound track 65 are combined in parallel to each other in a picture sequence 60.

[0050] The first recorded image 61 of image sequence 60 can be assigned to the time of input 67 of the stop signal 46. The audio track 65 is not simply a horizontal line, but exhibits a noise level that reproduces the normal operating noises of the escalator 1 at nominal speed VN. The signal input position 81, shown with a dashed line, at the time of the stop signal 46 can be read and recorded on the first image 61 from the position of the marker 53 to the measuring scale 31.

[0051] If, in the present exemplary embodiment, the Figures 5A to 5C according to arrow 70, the audio track 65 with finger 74 against the one from the software application 38 (see Figure 3 ) when the fixed marker 75 generated on screen 39 is moved, the subsequent images of the image sequence 60 are displayed on screen 39 in chronological order.

[0052] As shown in Figures 5A and 5B, audio track 65 exhibits a sudden increase in noise level, which then decreases continuously. This section of audio track 65 contains the brake operating noise 51. The second figure 62 shows the position of marker 53 relative to the linear measuring scale 31 at a starting point 68, at which the simultaneously recorded brake operating noise 51 begins. The second figure 62 is displayed when the sudden increase in noise level coincides with the fixed mark 75. Again, the position of marker 53 can be read from the measuring scale 31 and recorded as the starting position 82 of the brake operating noise 51.The distance traveled from marker 53 between signal input position 81 and start position 82 is the reaction length LR, which arises from the fact that the control unit 14 and the components involved in a braking operation, such as contactors for interrupting the ventilation flow (not shown) and the brake 18 itself, have a certain reaction time.

[0053] The third image 63 of image sequence 60 shows the position of the marker 53 relative to the linear measuring scale 31 at the point in time when the simultaneously recorded brake operating noises 51 on the audio track 65 end and thus the conveyor belt 26 is stationary. The third image 63 is displayed when the noise level of the audio track 65 has dropped to its lowest level. The audio track 65 now only exhibits background noise. Since the conveyor belt 26 is stationary from this point onward, all subsequent images of image sequence 60 look exactly the same. Instead of precisely determining the end of the brake operating noise 51, an image 63 is preferably chosen that reliably depicts a static state of the conveyor belt 26. This is the case when two temporally separated images at the end of image sequence 60 show an identical position of the marker 53 relative to the measuring scale 31.Again, the position of mark 53 can be read from the measuring scale 31 and recorded as final position 83.

[0054] As the Figures 5B and 5C show, disappears at Figure 5A The defined marker 53 is reached when advancing the audio track 65 with finger 74 at the bottom edge of the image; therefore, in image 5B, the subsequent gap between two escalator steps 3 is defined as marker 53' as a temporary measure. Accordingly, a new starting position 82' is also read and recorded on the measuring scale 31 as a temporary measure.

[0055] The distance traveled from marker 53' between the starting position 82' and the end position 83' is the actual braking distance LB during the application of brake 18. As mentioned at the beginning, the standard EN115-1 stipulates that braking distance measurement must begin at input 67, or from the occurrence of the stop signal 46, until the conveyor belt 26 has come to a complete standstill. This standard braking distance can be determined by simply adding the reaction length LR and the braking distance LB.

[0056] The previously described manual evaluation of image sequence 60 can also be automated using an image processing program. This involves performing an image analysis of the optically represented progression of the recorded brake operating noises 51 in image sequence 60 and marking the image in image sequence 60 containing the starting point 68 of the brake operating noise 51, as well as one of the images in image sequence 60 where the cessation of the brake operating noise 51 is clearly recognizable. In the automated process, the braking distance LB between the starting position 82 and the end position 83 is also determined by comparing the two marked images in image sequence 60. Here, the different positions of the marker 53 relative to the measuring scale 31 are read, and the braking distance LB is determined by calculating the difference. Although in the Figures 1 and 2Since escalators are shown, it is obvious that the braking distance measuring device 30 and the associated procedure can also be used for moving walkways.

[0057] Finally, it should be noted that terms such as "indicating", "comprehensive", etc. do not exclude other elements or steps, and terms such as "a" or "an" do not exclude a multitude.

Claims

1. A method for measuring a braking distance (LB) of an escalator (1) or moving walkway, wherein the escalator (1) or moving walkway has a conveyor belt (26), at least one drive motor (19) for driving the conveyor belt (26), a brake (18) for braking the conveyor belt (26) and a controller (14), wherein the drive motor (19) and the brake (18) can be controlled by the controller (14) and wherein a braking distance measuring device (30) is arranged at least temporarily in the region of the conveyor belt (26), wherein the braking distance measuring device (30) comprises at least one trigger device (45) which can be connected to the controller (14), an optically detectable linear measuring scale (31) and an optical sensor (35), characterized in, that • the linear measuring scale (31) is arranged on the escalator (1) or moving walkway in such a way that its course of movement relative to a marking (24, 53, 54, 55) as a result of a movement of the conveyor belt (26) can be detected by the optical sensor (35); • the conveyor belt (26) is brought to a specified speed (VV); • once the specified speed (VV) is reached, a stop signal (46) is sent to the controller (14) by means of the trigger device (45); • the recording of the relative course of movement is carried out by means of the optical sensor (35) at least from the stop signal (46) until the conveyor belt (26) comes to a complete standstill; and • the braking distance measuring device (30) moreover comprises an acoustic sensor (36) that records the braking operation noises (51) of the brake (18) in synchronization with the optical recording.

2. The method according to claim 1, wherein the recording of the relative movement and the recording of the braking operation noises (51) recorded synchronously with the relative movement are shown as a graphically displayed audio track (65), parallel to each other in an image sequence (60).

3. The method according to claim 2, wherein a start position (82, 82') of the marking (24, 53, 54, 55) relative to the measuring scale (31) is extracted from the image sequence (60) using a start point (68) of the braking operation noise (51), and an end position (83) of the marking (24, 53, 54, 55) relative to the measuring scale (31) is extracted from the elimination of the braking operation noise (51).

4. The method according to claim 3, wherein the start position (82, 82') and end position (83) are determined by means of an image processing program by carrying out an image analysis of the course of the recorded braking operation noises (51) optically displayed in the image sequence (60) and by marking in the image sequence (60) the image (62) of the image sequence (60) containing the start point (68) of the braking operation noise (51) and one of the images of the image sequence (60) in which the disappearance of the braking operation noise (51) can be clearly recognized.

5. The method according to claim 4, wherein the braking distance (LB) between the start position (82, 82') and the end position (83) is determined by comparing the two marked images (62, 63) of the image sequence (60) in that the different positions of the marking (24, 53, 54, 55) relative to the measuring scale (31) are read out and the braking distance (LB) is determined by calculating the difference.

6. The method according to any one of claims 1 to 5, wherein the trigger device (45) is connected to the controller (14) and receives operating data of the drive motor (19) from the controller (14), wherein a stop signal (46) is sent to the controller (14) as soon as the drive motor (19) has reached a speed that corresponds to the specified speed (VV) of the conveyor belt (26).

7. The method according to any one of claims 1 to 5, wherein a stop signal (46) can be manually input into the trigger device (45), which stop signal (46) is transmitted directly from the trigger device (45) to the controller (14).

8. A braking distance measuring device (30) for carrying out the method on an escalator (1) or moving walkway according to any one of claims 1 to 7, characterized in that the braking distance measuring device (30) comprises at least one trigger device (45) which can be connected to the controller (14), an optically detectable linear measuring scale (31), an optical sensor (35), and an acoustic sensor (36).

9. The braking distance measuring device (30) according to claim 8, wherein the optical sensor (35), the acoustic sensor (36), and the trigger device (45) are part of a smartphone (32) or tablet with a software application (38), wherein the software application (38) comprises at least program steps which allow for synchronous recording of a movement of the marking (24, 53, 54, 55) relative to the measuring scale (31) and of the braking operation noises (51).

10. The braking distance measuring device (30) according to claim 9, wherein it comprises a holder (33) for the smartphone (32) or tablet, which holder (33) can be temporarily arranged on a fixed part of an escalator (1) or moving walkway.

11. An escalator (1) or moving walkway having a brake measuring device (30) according to any one of claims 8 to 10, characterized in that at least the linear measuring scale (31), the optical sensor (35), and the acoustic sensor (36) of the braking distance measuring device (30) are arranged in a drive region (13) of the escalator (1) or moving walkway.

12. The escalator (1) or moving walkway according to claim 11, wherein the marking (53, 54) is arranged or defined on the conveyor belt (26), and the measuring scale (31) is arranged on a fixed part of the escalator (1) or moving walkway.

13. The escalator (1) or moving walkway according to claim 12, wherein the marking (53) is a gap between two escalator steps (3) of the conveyor belt (26) of the escalator (1), or is a gap between two pallets of the conveyor belt (26) of the moving walkway, or is a marking (54) that can be temporarily applied to the conveyor belt (26).

14. The escalator (1) or moving walkway according to claim 11, wherein the measuring scale (56) is arranged on the conveyor belt (26), and the marking (24, 55) is arranged on a fixed part of the escalator (1) or moving walkway.

15. The escalator (1) or moving walkway according to claim 14, wherein the marking (55) is an arrow-shaped sticker which can be temporarily attached to a fixed part of the escalator (1) or moving walkway.

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