EP4217303B1 - Handrail tension monitoring device for a people conveyor - Google Patents

Description

The present invention relates to a continuously conveying, walkable passenger transport system which is designed as an escalator or moving walkway.

Escalators and moving walkways are used to transport passengers standing on tread units such as steps or pallets within buildings or structures.

An escalator or moving walkway has a moving handrail on each side. These are used so that passengers can hold on to one of the handrails of the escalator or moving walkway in order to stay balanced and not fall. For example, a passenger can lose his balance if he receives an unexpected push from another passenger or the escalator or moving walkway stops abruptly. The transitions on escalators between the horizontal travel sections of the boarding and alighting areas and the sloping travel section in between also pose a certain risk of falling if the steps move vertically relative to one another and the passenger on the upper step has his toes just barely placed on the edge of the step.

However, it must be ensured that the handrail moves as synchronously as possible with the step belt or pallet belt. Since the handrails or handrail belts are usually driven by a friction drive, the handrail must be sufficiently pre-tensioned against the friction wheel so that the friction force between the handrail and the friction wheel of the handrail drive is high enough to prevent slippage between these two friction partners.

To tighten the handrail, the JP2008063056 A For example, a handrail tensioning device with a tensioning element is described. Due to signs of wear and settling as well as the constant bending changes during operation, the handrail becomes longer and must therefore be re-tensioned from time to time. In order to detect the time of re-tensioning, a sensor is installed in this handrail tensioning device that senses the end position of the tensioning element and sends a signal to the control system of the passenger transport system as soon as this is reached and the handrail must be re-tensioned. The The problem with this device is that the time for re-tensioning is only displayed when it is necessary, but no prediction of a likely maintenance date can be made.

In addition, the handrail pre-tensioning force must not be too high, as otherwise the handrail will be pressed too strongly against the guide rollers and guide profiles with which it is guided all around, and the energy required to move the handrail and the associated wear on these parts will be too high. Excessive handrail pre-tensioning cannot be detected with this sensor either.

The object of the present invention is therefore to achieve a precise and more meaningful determination of the existing handrail preload force.

This task is solved by a handrail voltage monitoring device for a passenger transport system designed as a moving walkway or escalator. For this purpose, the handrail voltage monitoring device has at least one distance sensor and one signal processing unit. The measurement signals recorded by the distance sensor can be processed and evaluated in the signal processing unit, whereby the oscillation frequency of a scanned handrail of the passenger transport system can be determined in the signal processing unit from the signal curve of the measurement signals. The determined oscillation frequency can be compared with at least a lower threshold value, whereby an alarm signal is generated if the lower threshold value is undershot.

In other words, the handrail pre-tension force is assessed based on the vibration behavior of the handrail, analogous to a vibrating wire. Known parameters are the length of a freely suspended section of the handrail, its structure, dimensions and materials used, as well as the measured parameters of vibration frequency and, if applicable, the amplitude height. The parameter to be determined is the handrail pre-tension force. The higher the handrail pre-tension force, the higher the vibration frequency of the handrail and vice versa. As soon as the determined vibration frequency falls below the lower threshold value, the minimum handrail pre-tension force is exceeded and this can lead to slippage between the friction partners mentioned above. The vibration behavior or the A change trend can also be identified from the changing vibration frequency, which can be extrapolated. This extrapolation can be used to predict when the lower threshold is reached and the handrail needs to be re-tightened. This makes maintenance planning much easier.

The handrail is preferably caused to vibrate by its movement during conveying operation. If necessary, the vibration can be stimulated by a suitably designed device such as a briefly switched-on alternating magnetic field, since the handrails usually have tension members made of steel strands.

The lower threshold value is a comparison value that represents the minimum required handrail pre-tension force. The lower threshold value and the upper threshold value described below are preferably determined after assembly of a passenger transport system by tests on it and can then be used for all identical and possibly even similar passenger transport systems. Of course, the threshold values can also be determined specifically for each completed passenger transport system and, for example, stored in a storage medium of the signal processing unit and retrieved from it. Thanks to the lower threshold value, with the help of operating status information (whether the passenger transport system is stationary or in conveying operation), a handrail failure (tearing) can also be detected immediately and suitable measures such as an emergency stop of the passenger transport system can be initiated.

As already mentioned, the determined vibration frequency can also be compared with at least one upper threshold value, whereby a warning signal is generated if the upper threshold value is exceeded. The upper threshold value represents the maximum permissible handrail pre-tension force.

In order to be able to install the handrail voltage monitoring device in the passenger transport system, it preferably has a holder for the distance sensor, whereby this holder can be mounted on a fixed component of the passenger transport system. The holder can be designed in such a way that when the handrail voltage monitoring device is in operation, the distance sensor is mounted in a freely suspended area of the handrail is directed against a hand rest surface or against the back of the handrail. The hand rest surface is the broad surface of the handrail on which the user rests their hand, grasping the two sides of the handrail with their thumb and fingers. The back of the handrail is usually provided with a slippery fabric so that it can glide as well as possible on the surfaces of a guide profile. In this arrangement, the hand rest surface or back of the handrail moves towards or away from the sensor. The continuously recorded measurements from the distance sensor result in a measurement curve that reflects the vibrations occurring on the handrail. Continuous recording of the measurements can also be understood to mean recording in discrete steps with a high cadence and the like, which result in a meaningful and analyzable measurement curve.

To simplify installation, the bracket can have adjustment means for aligning the distance sensor relative to the hand rest surface or the back of the handrail. During installation, the distance sensor can be aligned with the handrail in such a way that, on the one hand, the distance can be continuously measured with sufficient precision and, on the other hand, that the handrail does not collide with the distance sensor when the minimum preload and thus the greatest amplitude is reached.

A TOF camera, an infrared distance sensor, a laser distance sensor, an ultrasonic sensor with time-of-flight detection or a radar sensor can be used as a distance sensor. Basically, any sensor that can record the vibrations as a distance signal curve can be used.

The signal processing unit of the handrail voltage monitoring device can be implemented, for example, in the distance sensor, in a control system of the passenger transport system or in a data cloud. In other words, the signal processing unit is not tied to a specific location, but it must be connected to the distance sensor by cable and/or wireless signal transmission or at least be able to be connected periodically.

As soon as the signal processing unit detects that the lower threshold value or if the upper threshold is exceeded, it can issue an alarm signal and/or warning signal. This alarm signal and/or warning signal can be transmitted to a control system of the passenger transport system. This can influence the operation of the passenger transport system in such a way that it is stopped immediately, the driving speed is reduced or a time is waited until only a low number of users is registered by another sensor and only then is the escalator shut down for appropriate maintenance work.

Preferably, each passenger transport system has a handrail voltage monitoring device for each of its handrails.

Furthermore, the handrail voltage monitoring device can have a signal transmission device or can be connected to a signal transmission device via which at least the recorded signal curve of the measurement signals can be transmitted to a digital double data set of the passenger transport system.

In other words, parallel to the physically existing passenger transport system, a digital doppelganger data set that virtually maps this passenger transport system can be available. The measurement signals or signal curves generated by the distance sensor can be transmitted to the digital doppelganger data set via the signal transmission device. By processing these measurement signals and signal curves in conjunction with the data from the digital doppelganger data set, dynamic processes of the passenger transport system in operation can be simulated and displayed in real time on the digital doppelganger data set.

The digital doppelgänger dataset includes the characterizing properties of components of the physical passenger transport system in a machine-processable manner. It is constructed from component model datasets that include data determined by measuring characterizing properties on the physical passenger transport system after it has been assembled and installed in a structure.

The characterizing properties of the physical components can be geometric Dimensions of the component, the weight of the component and/or the surface quality of the component. Geometric dimensions of the components can be, for example, a length, a width, a height, a cross-section, radii, roundings, etc. of the components. The surface quality of the components can, for example, include roughness, textures, coatings, colors, reflectivities, etc. of the components. The characterizing properties can also be dynamic information, for example a motion vector of a component model data set that indicates its direction of movement and speed relative to surrounding component model data sets or to a static reference point of the digital doppelganger data set.

The characterizing properties can refer to individual components or groups of components. For example, the characterizing properties can refer to individual components from which larger, more complex groups of components are assembled. Alternatively or additionally, the properties can also refer to more complex equipment composed of several components, such as drive machines, gear units, conveyor chains, etc.

For example, signals from the distance sensor are transferred as measurement data to the digital doppelganger data set and, using a set of rules, characterizing properties of the component model data sets affected by the transferred measurement data are newly determined. The characterizing properties of the affected component model data sets are then updated with the newly determined, characterizing properties. Specifically, for example, the vibration frequency and amplitude measured by the distance sensor can be transferred to the component model data set representing the handrail and to the guide profiles and guide rollers that form the component model data sets that guide the handrail. This means that, for example, in the digital doppelganger data set displayed on a screen as a virtual representation, all dynamically movable component model data sets can be displayed with the same movements as their physical components in the physical passenger transport system at the time the signals are recorded. The interactions of the component model data sets can be simulated from the movements of the component model data sets and can be determined using the corresponding, known calculation programs from the fields of physics, mechanics and strength of materials, which determine the forces acting on the components.

Then, through monitoring, changes and change trends in the updated characterizing properties of the all-round handrail and their influence on the handrail and on the components interacting with it can be tracked and assessed using the digital doppelgänger dataset through calculations and/or static and dynamic simulations. This makes it possible to determine the time of maintenance very precisely and, if necessary, to create a list of the components interacting with the handrail that need to be replaced due to wear. Of course, assessments of dynamic processes that exceed the limit values are also possible using the digital doppelgänger dataset, for example in the case of increasing resonance vibrations.

The present invention also includes a method for processing and evaluating measurement signals from the handrail tension monitoring device described above. In the signal processing unit, the vibration frequency of the scanned handrail is determined from the signal curve of the measurement signals and the determined vibration frequency is compared with at least one lower threshold value. From the comparison (change trend of the vibration frequency) and the difference to the lower threshold value), a maintenance time can be determined, for example, when the handrail must be re-tensioned. If the lower threshold value is undershot, an alarm signal is generated, which is transmitted to the control system of the passenger transport system for further processing, for example. Based on the alarm signal, the system can, for example, stop the drive and send a message to a maintenance center.

The determined oscillation frequency can also be compared with at least one upper threshold value in the signal processing unit, whereby a warning signal is generated if the upper threshold value is exceeded. The drive does not necessarily have to be stopped as a result of the warning signal. However, in order to avoid excessive wear, the signal processing unit can, for example, send a message to the mobile phone of the maintenance employee who has just tightened the handrail too much.

To verify the vibration frequency from the signal curve of the measurement signals, a number of consecutive amplitude heights of the vibrating handrail can be determined and compared with a height limit value and a number limit value. If a certain number of amplitudes exceed the height limit value, this confirms that the vibration frequency or the handrail pre-tension force is too low.

As already mentioned, the recorded signal curve can be transmitted to a digital duplicate data set of the passenger transport system and the effects of the swinging handrail on other components of the passenger transport system can be determined by means of static and dynamic simulations.

Since the tensile forces in the handrail vary depending on the direction of rotation due to the friction conditions and the position of the handrail drive relative to the position of the distance sensor, the oscillation frequency of a handrail is usually dependent on the direction of travel. The threshold values can therefore be set depending on the direction of travel.

It is noted that some of the possible features and advantages of the invention are described herein with reference to different embodiments. A person skilled in the art will appreciate that the features can be suitably combined, adapted or exchanged to arrive at further embodiments of the invention, as long as they are within the scope of protection defined by independent claims 1 and 9.

• Figur 1 zeigt schematisch die wichtigsten Komponenten beziehungsweise Bauteile einer Fahrtreppe, insbesondere deren Handlauf und deren Handlaufspannvorrichtung sowie die Komponenten einer erfindungsgemässen Handlaufspannungs-Überwachungseinrichtung mit einem Distanzsensor.
• Figur 2 zeigt in vergrösserter Darstellung die Handlaufspannvorrichtung und den Distanzsensor der Handlaufspannungs-Überwachungseinrichtung der in Figur 1 dargestellten Personentransportanlage.
• Figur 3A zeigt einen fiktiven Signalverlauf der Messsignale des in den Figuren 1 und 2 dargestellten Distanzsensors.
• Figur 3B zeigt eine mögliche Auswertung der in Figur 3A dargestellten Messignale.

Embodiments of the invention will now be described with reference to the accompanying drawings, wherein neither the drawings nor the description are to be construed as limiting the invention.

• Figure 1 shows schematically the most important components or parts of an escalator, in particular its handrail and its handrail tensioning device as well as the components of an inventive handrail tension monitoring device with a distance sensor.
• Figure 2 shows an enlarged view of the handrail tensioning device and the distance sensor of the handrail tension monitoring device of the Figure 1 illustrated passenger transport system.
• Figure 3A shows a fictitious signal curve of the measurement signals of the Figures 1 and 2 shown distance sensor.
• Figure 3B shows a possible evaluation of the Figure 3A displayed measurement signals.

The figures are merely schematic and not to scale. The same reference symbols in the various figures indicate the same or equivalent features.

The Figure 1 shows schematically the most important components or parts of a passenger transport system 1 designed as an escalator. This has a supporting structure 3, which is shown in outline, which is arranged between two support points 5, 7 of a structure 9. The supporting structure 3 accommodates the other components of the passenger transport system 1, such as a conveyor belt 11 running all the way around in the supporting structure 3, two balustrades 13, each with a handrail 15 running all the way around (only one balustrade 13 shown), a drive unit 17 for driving the conveyor belt 11 and the handrails 15, and a control 19, which is connected to the drive unit 17 via a signal line 49 for controlling the drive unit.

In the present example, a returning strand 21 of the handrail 15 is guided in a balustrade base 25 by means of guide rollers 27, while its leading strand 23 is guided on guide profiles 29 (see Figure 2 , section AA). The part of the handrail 15 that is visible and therefore tangible to users is the leading strand 23, while the returning strand 21 is hidden in the balustrade base 25.

The drive unit 17 is operatively connected to a main drive shaft 31. The conveyor belt 11 is also guided around the main drive shaft 31 and is driven by it. The handrail 15 is driven by friction wheels 35 of a handrail drive 33, whereby these friction wheels 35 are also operatively connected to the drive unit 17 via the main drive shaft 31. In order to ensure sufficient power transmission A handrail tensioning device 37 is provided so that the friction wheels 35 and the handrail 15 can be tensioned. The handrail 15 can be pre-tensioned by means of this. Like the return run 21 of the handrail 15, the handrail tensioning device 37, the handrail drive 33 and the guide rollers 27 that guide the handrail 15 in places are also arranged within the balustrade base 25.

Furthermore, a distance sensor 43 of a handrail voltage monitoring device 41 is arranged in the balustrade base 25. The distance sensor 43 is connected to the controller 19 of the passenger transport system 1 via a signal line 45 shown with a broken line. As indicated, a signal processing unit 47 of the handrail voltage monitoring device 41 can be arranged in the controller 19 or implemented in its electronics. However, it can also be implemented in the distance sensor 43 itself, or even outside the physical area of the passenger transport system 1, for example in a data cloud 95.

In order to be able to detect vibrations of the handrail 15, the distance sensor 43 is arranged in a freely suspended area 57 of the handrail 15, preferably between two guide rollers 27. Depending on the existing handrail pre-tensioning force, the handrail sags to varying degrees in the freely suspended area 57. If it is correctly tensioned, it sags slightly as shown by the solid line 51. If it is tensioned too tightly, it is more likely to be in the position shown by the dot-dash line 53, and if it is not tensioned enough, it is in the position shown by the broken line 55.

Figure 2 shows in enlarged view the handrail tensioning device 37 and the distance sensor 43 of the handrail tension monitoring device 41 of the Figure 1 illustrated passenger transport system 1. The handrail tensioning device 37 has a roller carrier 69 with pressure rollers 67, a spindle 63, adjusting nuts 65 and a support 61. The support 61 is attached to a fixed component 81 of the passenger transport system 1, in the example shown to an upper chord of the supporting structure 3, for example with screws. The spindle 63, which is firmly connected to the roller carrier 69, can be adjusted relative to the support 61 by means of the adjusting nuts 65. so that the desired handrail pre-tensioning force can be applied to the handrail 15. Of course, handrail tensioning devices 37 with different designs can also be used, for example with a spring element. However, such a handrail tensioning device 37 must also be re-tensioned from time to time.

The handrail tension monitoring device 41 has a holder 71, which is also mounted on the upper belt or on a fixed component 81 of the passenger transport system 1. The holder 71 is designed such that, in the operating state of the handrail tension monitoring device 41, its distance sensor 43, more precisely a sensor head 77 of the distance sensor 43 in a freely suspended area 51 of the handrail 15, is directed against a hand support surface 83 or against a rear side 85 of the handrail 15. The holder 71 also has adjustment means 73, 75 for aligning the distance sensor 43 relative to the hand support surface 83 or the rear side 85 of the handrail 15. In the present embodiment, these adjustment means 73, 75 are adjusting nuts 75, which also serve to fasten the distance sensor, and slotted screw connections 73 to mount and align the bracket 71 on the fixed component 81.

The distance sensor 71 must be able to carry out a rapid sequence of distance measurements, i.e. to record the changing distances caused by vibrations (represented by the double arrow 87 and the deflections of the handrail in the freely suspended area 51 indicated by broken lines) as measurement signals and their signal progression. Various distance sensors 71 are suitable for this purpose, such as a TOF camera, an infrared distance sensor, a laser distance sensor, an ultrasonic sensor with time-of-flight detection or a radar sensor.

As already mentioned, the measurement signals and their signal curves are transmitted to the signal processing unit 47, for example via the signal line 45. Of course, instead of a signal line 45, wireless transmission can also take place, for example via a Bluetooth connection and the like.

The signal processing unit 47 itself can be arranged in the distance sensor 71. However, as in the Figure 1 shown, also in the control 19 of the Passenger transport system 1. It is also possible for the signal processing unit 47 to be implemented in a data cloud and for the required evaluations to be carried out there. In addition, the handrail voltage monitoring device 41 can have communication means 89 or can be connected to communication means 89, via which at least the recorded signal curve of the measurement signals can be transmitted to a digital double data set 101 of the passenger transport system 1.

A possible evaluation of the measurement signals M and the signal curve MV are given in the Figures 3A and 3B shown. The Figure 3A shows a fictitious signal curve MV of the measurement signals M of the Figures 1 and 2 shown distance sensor 43.

The signal curve MV shown shows a low amplitude A and a high oscillation frequency f starting on the left. Over the operating time t, a loss of pre-tensioning force occurs on the handrail 15 as a result of settling phenomena in the material of the handrail 15 and due to wear. As a result, the handrail 15 is able to oscillate increasingly further, so that the oscillation frequency f drops and the amplitude height H of the amplitudes A increases. Of course, the loss of pre-tensioning force does not occur within a few oscillations, but actually over a very long period of time.

The Figure 3B shows the frequency curve FK determined from the signal curve MV as well as an upper threshold value OS and a lower threshold value US. Starting on the left, the measured oscillation frequency f is so high that the frequency curve FK exceeds the upper threshold value OS. The handrail 15 is therefore much too tightly tensioned, which is why a warning signal W is generated in the signal processing unit 47 and this is transmitted, for example, to the maintenance technician on his mobile phone, so that immediately after re-tensioning the handrail 15, he sees that the handrail pre-tensioning force is too high. He can then reduce the handrail pre-tensioning force so that the upper threshold value OS is not reached. Of course, the warning signal W can also be sent to the Figure 1 shown control 19 of the passenger transport system 1 and thereby the driving operation of the passenger transport system 1 can be stopped after a few seconds.

Due to the continuous operation of the passenger transport system 1, the handrail pre-tensioning force continuously, whereby the oscillation frequency f decreases and the amplitude height H increases. At some point the oscillation frequency f falls below the lower threshold value US, whereby an alarm signal Z is output by the signal processing unit 47. The lower threshold value US is dimensioned such that, under normal load of the handrail 15, there is just no slippage between the friction wheel 35 of the handrail drive 33 and the handrail 15 (see Figure 1 ). The lower threshold value US can be determined, for example, by means of tests, but it can also be calculated from the geometric data of the handrail drive 33, the friction coefficients between the handrail 15 and the various friction partners along the entire handrail guide section, and the handrail pre-tension force.

Since the tensile forces in the handrail 15 vary depending on the direction of rotation as a result of the friction conditions and the position of the handrail drive 33 and the handrail tensioning device 37 relative to the position of the distance sensor 71, the oscillation frequency f of a handrail 15 depends on the direction of travel. Consequently, the threshold values can be set depending on the direction of travel.

The alarm signal Z is transmitted to the control system 19 of the passenger transport system 1 and, for safety reasons, this stops the operation of the passenger transport system 1, for example, until the handrail 15 has been re-tightened by means of the handrail tensioning device 37.

As from the Figure 3A As can be seen, in order to verify the oscillation frequency f, a number of consecutive amplitude heights H of the oscillating handrail 15 can be determined from the signal curve MV of the measurement signals M and these can be compared with a height limit value HG and a number limit value n. This means that an inadmissibly low handrail pre-tensioning force can be determined even if the handrail 15 is stimulated to oscillate at a higher frequency by external influences, for example by rapidly tugging on the handrail 15 and thus does not fall below the lower threshold value US. In this special case, the amplitude height H reveals that the handrail pre-tensioning force is too low. At the same time, however, one-off exceedances of the height limit value HG are not taken into account due to the number limit value n, so that an alarm signal A is only generated if the height limit value HG in the period under consideration or in the several consecutive amplitudes A was exceeded several times.

In the Figure 1 a further possibility is shown for evaluating the measurement signals M and their signal curve MV of the handrail voltage monitoring device 41 or of its distance sensor 43. For this purpose, a digital doppelganger data set 101 is used, which is stored, for example, in a data processing device 95 (cloud). This digital doppelganger data set 101 virtually maps the passenger transport system 1. This means that every single component of the passenger transport system 1 is also reproduced in the digital doppelganger data set 101. Preferably, the digital doppelganger data set 101 is structured into component model data sets 113, which are linked to one another via interface information. In other words, the components of the passenger transport system 1 are reproduced as component model data sets 113. Each of these component model data sets 113 (for example, the component model data set 113 of the guide roller 27) has as completely as possible all of the characterizing properties of the physical component to be mapped. Furthermore, the interface information present in the digital doppelgänger data set 101 is there to represent the arrangement of the components in three-dimensional space relative to one another, their interaction with one another during the action and transmission of forces, moments and the like, as well as, if applicable, their degrees of freedom of movement relative to one another.

This digital doppelgänger data set 101 can be downloaded from the data processing device 95, further processed and used for simulations 105, for example via an input/output interface 99, in the example shown a personal computer. Of course, the simulations 105 can also be carried out in the data processing device 95, in which case the input/output interface 99 can only have the function of a computer terminal.

In order to be able to carry out the simulations 105, it is possible, as shown by the double arrow 97, to transfer the measurement signals and the signal curve of the distance sensor 43 to the digital double data set 101 via the signal transmission device 89 of the handrail voltage monitoring device 41. Supplemented in this way, the simulations 105 can then be carried out with this. by examining how the measurement signals M of the handrail voltage monitoring device 41 affect the individual virtual components of the digital doppelganger data set 101, which are represented by component model data sets 113. During the entire implementation of the simulation 105, the input/output interface 99 is in communication with the data processing device 95, as shown by the double arrow 115. Accordingly, the simulation 105 and the simulation results 107 can be shown as a virtual representation 103 on the input/output interface 99. This allows processes that occur in the passenger transport system 1 in operation to be shown in evaluated form in real time on the input/output interface 99.

Although the Figures 1 and 2 show a passenger transport system 1 designed as an escalator, it is obvious that the present invention can also be used in a passenger transport system 1 designed as a moving walkway.

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 can also be used in combination with other features or steps of other embodiments described above, provided they are within the scope of protection of independent claims 1 and 9. Reference signs in the claims are not to be regarded as a limitation.

Claims (12)

1. Handrail tension monitoring device (41) for a passenger transport system (1) designed as a moving walkway or escalator, the handrail tension monitoring device (41) comprising at least a distance sensor (34) and a signal processing unit (47) and the measurement signals (M) detected by the distance sensor (34) being able to be processed and evaluated in the signal processing unit (47), characterized in that the vibration frequency (f) of a scanned handrail (15) of the passenger transport system (1) can be determined in the signal processing unit (47) from the signal curve (MV) of the measurement signals (M) and the determined vibration frequency (f) can be compared to at least one lower threshold value (US) and/or upper threshold value (OS), an alarm signal (Z) being generated if the lower threshold value (US) is not reached and a warning signal (W) being generated if the upper threshold value (OS) is exceeded.
2. Handrail tension monitoring device (41) according to claim 1, wherein said device comprises a holder (37) which can be mounted on a stationary component (81) of the passenger transport system (1), wherein the holder (37) is designed such that in the operating state of the handrail tension monitoring device (41), the distance sensor (34) thereof is directed, in a freely suspended region (51) of the handrail (15), against a hand support surface (83) or against a rear side (85) of the handrail (15).
3. Handrail tension monitoring device (41) according to claim 2, wherein the holder (37) has adjustment means (73, 75) for aligning the distance sensor (34) relative to the hand support surface (83) or to the rear side (85) of the handrail (15).
4. Handrail tension monitoring device (41) according to any of claims 1 to 3, wherein the distance sensor (34) is a TOF camera, an infrared distance sensor, a laser distance sensor, an ultrasonic sensor with transit time detection, or a radar sensor.
5. Handrail tension monitoring device (41) according to any of claims 1 to 4, wherein the signal processing unit (47) is implemented in the distance sensor (34), in a controller (19) of the passenger transport system (1), or in a data cloud (95).
6. Handrail tension monitoring device (41) according to any of claims 1 to 5, wherein the alarm signal (Z) and/or warning signal (W) can be transmitted to a controller (19) of the passenger transport system (1) and as a result the driving operation of the passenger transport system (1) can be influenced.
7. Handrail tension monitoring device (41) according to any of claims 1 to 6, wherein said device has communication means (89) or can be connected to communication means (89) via which at least the detected signal curve (MV) of the measurement signals (M) can be transmitted to a digital twin data record (101) of the passenger transport system (1).
8. Passenger transport system (1) having at least one handrail tension monitoring device (41) according to any of claims 1 to 7.
9. Method for processing and evaluating measurement signals (M) of a handrail tension monitoring device (41) according to any of claims 1 to 7, characterized in that in the signal processing unit (47), the vibration frequency (f) of the scanned handrail (15) is determined from the signal curve (MV) of the measurement signals (M) and the determined vibration frequency (f) is compared with at least one lower threshold value (US) and/or upper threshold value (OS), an alarm signal (Z) being generated if the lower threshold value (US) is not reached and a warning signal (W) being generated if the upper threshold value (OS) is exceeded.
10. Method according to claim 9, wherein in order to verify the vibrating frequency (f), a number of successive amplitude heights (H) of the vibrating handrail (15) are determined from the signal curve (MV) of the measurement signals (M) and said amplitude heights are compared with a height limit value (HG) and a number limit value (n).
11. Method according to either claim 9 or claim 10, wherein the detected signal curve (MV) is transmitted to a digital twin data record (101) of the passenger transport system (1) and the effects of the vibrating handrail (15) on other components of the passenger transport system (1) are determined by means of static and dynamic simulations using the digital twin data record (101).
12. Method according to any of claims 9 to 11, wherein the threshold values (OS, US) are established depending on the direction of travel.

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