HANDRAIL TENSION MONITORING DEVICE FOR A PASSENGER TRANSPORT SYSTEM

Abstract

A handrail tension monitoring device for a passenger transport system designed as a moving walkway or escalator can include a distance sensor and a signal processing unit. Measurement signals detected by the distance sensor can be processed and evaluated in the signal processing unit. A vibration frequency of a scanned handrail of the passenger transport system can be determined from the signal curve of the measurement signals and the vibration frequency can be compared with a lower threshold value or upper threshold value. An alarm signal can be generated if the lower threshold value is not reached and a warning signal can be generated if the upper threshold value is exceeded.

Claims

1-12. (canceled)

13. A handrail tension monitoring device for a passenger transport system configured as a moving walkway or escalator, the handrail tension monitoring device comprising: at least a distance sensor that produces measurement signals; and a signal processing unit that receives the measurement signals detected by the at least one distance sensor and processes the measurement signals to: determine a vibration frequency of a scanned handrail of the passenger transport system from a signal curve of the measurement signals, compare the vibration frequency to at least one of a lower threshold value or an upper threshold value, and generate an alarm signal if the lower threshold value is not reached and a warning signal if the upper threshold value is exceeded.

14. The device of claim 13, wherein further comprising a holder configured to be mounted on a stationary component of the passenger transport system, wherein the holder is configured such that, in the operating state of the handrail tension monitoring device, the distance sensor thereof is directed, in a freely suspended region of the handrail, against a hand support surface or against a rear side of the handrail.

15. The device of claim 14, wherein the holder comprises an adjustment device for aligning the distance sensor relative to the hand support surface or to the rear side of the handrail.

16. The device of claim 13, wherein the distance sensor is a TOF camera, an infrared distance sensor, a laser distance sensor, an ultrasonic sensor with transit time detection, or a radar sensor.

17. The device of claim 13, wherein the signal processing unit is implemented in the distance sensor, in a controller of the passenger transport system, or in a data cloud.

18. The device of claim 13, wherein the alarm signal or warning signal is transmitted to a controller of the passenger transport system, and as a result, driving operation of the passenger transport system is influenced.

19. The device of claim 13, wherein the device comprises a communication module configured such that the at least the detected signal curve of the measurement signals can be transmitted to a digital twin data record of the passenger transport system.

20. A passenger transport system having at least one of the handrail tension monitoring device according to claim 13.

21. A method for processing and evaluating measurement signals of the handrail tension monitoring device of claim 13, wherein 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 or upper threshold value, an alarm signal being generated if the lower threshold value is not reached and a warning signal being generated if the upper threshold value is exceeded.

22. The method of claim 21, wherein in order to verify the vibrating frequency, a number of successive amplitude heights of the vibrating handrail are determined from the signal curve of the measurement signals and said amplitude heights are compared with a height limit value and a number limit value.

23. The method of claim 21, wherein the detected signal curve is transmitted to a digital twin data record of the passenger transport system and the effects of the vibrating handrail on other components of the passenger transport system are determined by means of static and dynamic simulations using the digital twin data record.

24. The method of claim 21, wherein the threshold values are established depending on the direction of travel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Embodiments of the disclosure will be described in the following with reference to the accompanying drawings, with neither the drawings nor the description being intended to be interpreted as limiting the disclosure.

[0033] FIG. 1 schematically shows the most important components or parts of an escalator, in particular the handrail and handrail tensioning device thereof as well as the components of a handrail tension monitoring device according to the disclosure having a distance sensor.

[0034] FIG. 2 is an enlarged illustration of the handrail tensioning device and the distance sensor of the handrail tension monitoring device of the passenger transport system shown in FIG. 1.

[0035] FIG. 3A shows a fictitious signal curve of the measurement signals of the distance sensor shown in FIGS. 1 and 2.

[0036] FIG. 3B shows a possible evaluation of the measurement signals shown in FIG. 3A.

[0037] The drawings are merely schematic and not true to scale. Like reference signs refer to like or equivalent features in the various drawings.

DETAILED DESCRIPTION

[0038] FIG. 1 schematically shows the most important components or parts of a passenger transport system 1 designed as an escalator. This system has a supporting structure 3, indicated by contour lines, which is arranged between two support points 5, 7 of a structure 9. Here, the supporting structure 3 accommodates the other components of the passenger transport system 1, such as a conveyor belt 11 guided continuously around the supporting structure 3, two balustrades 13 each having a continuously guided handrail 15 (only one balustrade 13 shown), a drive unit 17 for driving the conveyor belt 11 and the handrails 15, as well as a controller 19, which is connected via a signal line 49 to the drive unit 17 for controlling same.

[0039] 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 FIG. 2, section A-A). The part of the handrail 15 that is visible to the user and therefore can be gripped is the leading strand 23, while the returning strand 21 is hidden in the balustrade base 25.

[0040] 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 same. The handrail 15 is driven by friction wheels 35 of a handrail drive 33, these friction wheels 35 also being operatively connected to the drive unit 17 via the main drive shaft 31. A handrail tensioning device 37 is provided so that sufficient force can be transmitted between the friction wheels 35 and the handrail 15. The handrail 15 can be pretensioned by means of this tensioning device. Like the returning strand 21 of the handrail 15, the handrail tensioning device 37, the handrail drive 33 and the guide rollers 27 which guide the handrail 15 in places are also arranged within the balustrade base 25.

[0041] Furthermore, a distance sensor 43 of a handrail tension 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 tension monitoring device 41 can be arranged in the controller 19 or implemented in the electronics thereof. However, it can also be implemented in the distance sensor 43 itself, or even outside the physical region of the passenger transport system 1, for example, in a data cloud 95.

[0042] In order to be able to detect vibrations of the handrail 15, the distance sensor 43 is arranged in a freely suspended region 57 of the handrail 15, preferably between two guide rollers 27. Depending on the existing handrail pretensioning force, the handrail sags to different degrees in the freely suspended region 57. When 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 have the position shown by the dash-dotted line 53 and, if it is not tensioned enough, the position shown by the broken line 55.

[0043] FIG. 2 is an enlarged illustration of the handrail tensioning device 37 and the distance sensor 43 of the handrail tension monitoring device 41 of the passenger transport system 1 shown in FIG. 1. The handrail tensioning device 37 comprises 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 stationary component 81 of the passenger transport system 1, in the example shown on 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 pretensioning force can be applied to the handrail 15. Of course, handrail clamping devices 37 with different designs can also be used, for example, having a spring element. However, such a handrail tensioning device 37 must also be re-tensioned from time to time.

[0044] The handrail tension monitoring device 41 has a holder 71 which is also mounted on the upper chord or on a stationary 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, the distance sensor 43 thereof, more precisely a sensor head 77 of the distance sensor 43, 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. Furthermore, the holder 71 has adjustment means 73, 75 for aligning the distance sensor 43 relative to the hand support surface 83 or to the rear side 85 of the handrail 15. In the present embodiment, these adjusting means 73, 75 are adjusting nuts 75, which at the same time also serve to fasten the distance sensor, and slot-screw connections 73 in order to mount and align the holder 71 on the stationary component 81.

[0045] The distance sensor 71 must be able to carry out a quick sequence of distance measurements, e.g., to detect the changing distances caused by vibrations (represented by the double arrow 87 and the deflections of the handrail in the freely suspended region 51 indicated by broken lines) as measurement signals and the signal curve thereof. 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 transit time detection, or a radar sensor.

[0046] As already mentioned, the measurement signals and the signal course thereof are transmitted to the signal processing unit 47 via the signal line 45, for example. Of course, instead of a signal line 45, wireless transmission can also take place, for example, via a Bluetooth connection and the like.

[0047] The signal processing unit 47 itself can be arranged in the distance sensor 71. However, as shown in FIG. 1, it can also be integrated in the controller 19 of the passenger transport system 1. Furthermore, it is also possible for the signal processing unit 47 to be implemented in a data cloud and for the necessary evaluations to be made 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 detected signal curve of the measurement signals can be transmitted to a digital twin data record 101 of the passenger transport system 1.

[0048] A possible evaluation of the measurement signals M and the signal profile MV are shown in FIGS. 3A and 3B. FIG. 3A shows a fictitious signal curve MV of the measurement signals M of the distance sensor 43 shown in FIGS. 1 and 2.

[0049] The illustrated signal curve MV shows, beginning on the left, a low amplitude A and a high vibration frequency f. Over the operating time t, there is a loss of pretensioning force on the handrail 15 as a result of settling in the material of the handrail 15 and wear. As a result, the handrail 15 is able to vibrate further, so that the vibration frequency f decreases and the amplitude height H of the amplitudes A increases. Of course, the loss of pretensioning force does not occur within a few vibrations, but rather over a very long period of time.

[0050] FIG. 3B shows the frequency curve FK determined from the signal curve MV and an upper threshold value OS and a lower threshold value US. Starting on the left, the measured vibration frequency f is so high that the frequency curve FK exceeds the upper threshold value OS. The handrail 15 is therefore tensioned far too much, and therefore a warning signal W is generated in the signal processing unit 47 and is transmitted to the maintenance technician, for example, on his mobile phone, so that he can see immediately after re-tensioning the handrail 15 that the handrail pretensioning force is too high. He can then reduce the handrail pretensioning force to such an extent that the upper threshold value OS is not met. Of course, the warning signal W can also be transmitted to the controller 19 of the passenger transport system 1 shown in FIG. 1, thereby stopping the driving operation of the passenger transport system 1 after a few seconds.

[0051] Due to the continuous operation of the passenger transport system 1, the handrail pretensioning force decreases continuously, as a result of which the oscillation frequency f decreases and the amplitude height H increases. At some point the vibration frequency f falls below the lower threshold value US, in which case an alarm signal Z is output by the signal processing unit 47. The lower threshold value US is dimensioned such that with normal loading of the handrail 15 there is barely any slip between the friction wheel 35 of the handrail drive 33 and the handrail 15 (see FIG. 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, the handrail drive 33, the coefficient of friction between the handrail 15 and the various friction partners along the entire handrail guide route, and the handrail pretensioning force.

[0052] Since the tensile forces in the handrail 15 are different depending on the direction of rotation due to 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 vibration frequency f of a handrail 15 is dependent on the direction of travel. As a result, the threshold values can be established depending on the direction of travel.

[0053] The alarm signal Z is transmitted to the controller 19 of the passenger transport system 1 and, for safety reasons, this stops, for example, the driving operation of the passenger transport system 1 until the handrail 15 has been re-tensioned by means of the handrail tensioning device 37.

[0054] As can be seen from FIG. 3A, in order to verify the vibrating frequency f, a number of successive amplitude heights H of the vibrating handrail 15 can be 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. As a result, an impermissibly low handrail pretensioning force can also be determined when the handrail 15 is stimulated to vibrate at a higher frequency by external influences, for example, by rapid pulling at 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 pretensioning force is too low. At the same time, however, one-time exceedance of the height limit value HG due to the number limit value n is not taken into account, so that an alarm signal A is generated only when the height limit value HG has been exceeded several times in the period under consideration or in the plurality of successive amplitudes A.

[0055] FIG. 1 shows a further option for evaluating the measurement signals M and the signal curve MV thereof from the handrail tension monitoring device 41 or from the distance sensor 43 thereof. For this purpose, a digital twin data record 101 is used, which is stored, for example, in a data processing device 95 (cloud). This digital twin data record 101 maps the passenger transport system 1 virtually. This means that each individual component of the passenger transport system 1 is also reproduced in the digital twin data record 101. The digital twin data record 101 is preferably structured in component model data records 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 records 113. Each of these component model data records 113 (for example, the component model data record 113 of the guide roller 27) has all the characterizing properties of the physical component to be mapped as completely as possible. Furthermore, the interface information present in the digital twin data record 101 is there to reproduce the arrangement of the components in three-dimensional space, their interaction with one another during the action and transmission of forces, moments and the like, and possibly their degrees of freedom of movement with respect to one another.

[0056] This digital twin data record 101 can, for example, be downloaded from the data processing device 95 via an input/output interface 99, a personal computer in the example shown, processed further and used for simulations 105. Of course, the simulations 105 can also be carried out in the data processing device 95, the input/output interface 99 then only being able to function as a computer terminal.

[0057] In order to be able to carry out the simulations 105, as shown by the double arrow 97, there is, for example, the option of transmitting the measurement signals and the signal curve of the distance sensor 43 to the digital twin data record 101 via the signal transmission device 89 of the handrail voltage monitoring device 41. Supplemented in this way, this can be used to carry out the simulations 105 by examining how the measurement signals M of the handrail tension monitoring device 41 affect the individual virtual components of the digital twin data record 101 represented by component model data records 113.

[0058] 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 displayed as a virtual representation 103 on the input/output interface 99. In this way, processes that occur when the passenger transport system 1 is in operation can be represented in real time on the input/output interface 99 in an evaluated form.

[0059] Although FIGS. 1 and 2 show a passenger transport system 1 designed as an escalator, it is obvious that the present disclosure can also be used in a passenger transport system 1 designed as a moving walkway.

[0060] Finally, it should be noted that terms such as “comprising,” “having,” etc. do not preclude other elements or steps and terms such as “a” or “an” do not preclude a plurality. Furthermore, it should be noted that features or steps that have been 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 should not be considered to be limiting.