TECHNICAL FIELD

The invention concerns in general the technical field of elevators. More particularly, the invention concerns a monitoring solution for the elevator systems.

BACKGROUND

Elevator safety is one of the most important matters to ensure. The elevator systems comprise ropes, such as suspension ropes, compensation ropes and over-speed governor ropes, which are wearing parts having an estimated lifetime and for this reason a condition of the ropes needs to be monitored for ensuring safe use of the elevator system and life-time predictability in question.

Typically, the ropes used in the elevator solutions now-a-days are stranded steel wire ropes. The ropes may be affected by corrosion, chemical attack as well as mechanical attack which all may cause damages to the ropes. The challenge in traditional ways of monitoring the condition of the elevator ropes is to decide so- called discard criteria for replacing a damaged rope with a new one. Especially, the decision-making, and especially an evaluation of the rope condition, has been time-consuming and inaccurate with the traditional methods, because it is based on a visible detection of diameter reduction and broken wires within the rope. Additionally, a tolerance for rope permanent elongation may be monitored.

The documents WO 2021/032903 A1 and WO 2021/032904 A1 disclose solutions for monitoring the elevator ropes with a solution in which electromagnetic radiation is used for generating an image representation of the elevator rope which is analyzed in order to determine aspects with respect to the condition of the elevator rope in question. The elevator systems are implemented so that there are a plurality of elevator ropes running parallelly e.g. over the traction sheave or any pulley in order to enable a smooth operation of the elevator as well as to guarantee a safety of the elevator system. Due to the parallelly arranged elevator ropes, specifically when there are more than three elevator ropes in parallel, the width of the rope assembly becomes large and as a result the sensors shall extend over the whole width of the rope assembly in order to collect data of each rope. The width is such that there are only very scarce number of sensors available in the market and those are very expensive. On the other hand, due to varied configurations of the elevators especially in terms of the number of the elevator ropes in the rope assembly it challenging to adapt a plurality of sensors with fixed size (cf. width) in one line to cover the whole width of the rope assembly especially because it would lead to monitoring of a plurality of ropes with one sensor and, as a consequence, there is need to separate the data from sensor with a software solution which increases a complexity of the system, decreases accuracy, and adds costs.

Moreover, according to known solutions, it is possible to read the width of plurality of parallel ropes using one sensor, but due to varying mechanical arrangements of the elevator roping, this leads to costly adaptation work, wherein the data from sensor reading area needs to be divided, by means of the software, in a corresponding processing unit for measuring different parallel ropes individually for each elevator arrangement.

Therefore, there is a need to introduce alternative solutions which mitigate at least in part drawbacks of the available solutions and allow condition monitoring of elevator ropes in an efficient manner.

SUMMARY

The following presents a simplified summary in order to provide basic understanding of some aspects of various invention embodiments. The summary is not an extensive overview of the invention. It is neither intended to identify key or critical elements of the invention nor to delineate the scope of the invention. The following summary merely presents some concepts of the invention in a simplified form as a prelude to a more detailed description of exemplifying embodiments of the invention.

An object of the invention is to present an elevator system.

The objects of the invention are reached by an elevator system as defined by the respective independent claim.

According to a first aspect, an elevator system is provided, the elevator system comprising: at least three parallelly arranged elevator ropes, a measurement system for monitoring the at least three parallelly arranged elevator ropes, the measurement system comprises a sensor arrangement comprising a dedicated sensor for each of the at least three parallelly arranged elevator ropes for obtaining measurement data descriptive of each respective elevator rope, wherein each of the dedicated sensors is arranged parallelly in part in a travel direction of the parallelly arranged elevator ropes with at least one other dedicated sensor.

The each of the dedicated sensors may be arranged parallelly in part in the travel direction of the parallelly arranged elevator ropes with at least one other dedicated sensor by mounting each of the sensors transversally with respect to the travel direction of the elevator ropes.

Alternatively, the each of the dedicated sensors may be arranged parallelly in part in the travel direction of the parallelly arranged elevator ropes with at least one other dedicated sensor by mounting each of the sensors in a slanted position with respect to the travel direction of the elevator ropes.

It is also possible to arrange that at least one of the each of the dedicated sensors may be arranged parallelly in part in a travel direction of the parallelly arranged elevator ropes with at least one other dedicated sensor by mounting at least one dedicated sensor transversally with respect to the travel direction of the elevator ropes and at least one other dedicated sensor in a slanted position with respect to the travel direction of the elevator ropes.

The slanted position of the sensors may be arranged by mounting slanted sensors in an angle of 15 to 75 degrees with respect to the travel direction of the elevator ropes.

The sensing elements of the sensors may be arranged on one line.

The plurality of parallelly arranged elevator ropes may be arranged to travel at least in part along a pulley. The pulley may be at least one of: a traction sheave; a bedplate pulley; a diverter pulley.

The sensor arrangement may advantageously be arranged close to the pulley. Specifically, the sensor arrangement may be arranged close to the pulley on a side of the pulley on which a counter-weight is connected to the plurality of the parallelly arranged elevator ropes.

A width of the sensor may exceed a pitch distance between two adjacent elevator ropes.

The plurality of sensors may be mounted to a mounting bracket. The mounting bracket may comprise a fixing structure for installing a protection cover between the at least three parallelly arranged elevator ropes and the sensor arrangement. The fixing structure may be implemented with a groove arrangement configured to receive the protection cover.

The expression "a number of” refers herein to any positive integer starting from one, e.g. to one, two, or three.

The expression "a plurality of” refers herein to any positive integer starting from two, e.g. to two, three, or four. Various exemplifying and non-limiting embodiments of the invention both as to constructions and to methods of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific exemplifying and non-limiting embodiments when read in connection with the accompanying drawings.

The verbs “to comprise” and “to include” are used in this document as open limitations that neither exclude nor require the existence of unrecited features. The features recited in dependent claims are mutually freely combinable unless otherwise explicitly stated. Furthermore, it is to be understood that the use of “a” or “an”, i.e. a singular form, throughout this document does not exclude a plurality.

BRIEF DESCRIPTION OF FIGURES

The embodiments of the invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings.

Figure 1 illustrates schematically a portion of an elevator system according to an example.

Figure 2 illustrates schematically a portion of an elevator system according to another example.

Figures 3A-3C illustrates schematically sensor arrangements according to respective examples.

Figure 4 illustrates schematically a structure of a sensor according to an example.

Figure 5 illustrates schematically locations of elevator system according to various examples.

Figure 6 illustrates schematically a pulley of an elevator system according to an example. DESCRIPTION OF THE EXEMPLIFYING EMBODIMENTS

The specific examples provided in the description given below should not be construed as limiting the scope and/or the applicability of the appended claims. Lists and groups of examples provided in the description given below are not exhaustive unless otherwise explicitly stated.

Figure 1 schematically illustrates some entities of an arrangement forming a portion of an elevator system comprising a measurement system for elevator rope monitoring. The entities of Figure 1 provide an exemplifying framework for one or more embodiments of the present invention. In other words, the elevator system under monitoring comprises an elevator rope assembly comprising at least three elevator ropes 110 arranged to travel parallelly at least in a position of the monitoring. The monitoring in a manner according to the present invention may be arranged to any types of elevator ropes, such as suspension ropes, compensation ropes and over-speed governor ropes, or any combination of these. The elevator ropes 110 may e.g. connect an elevator car with a counterweight over further entities, such as over a traction sheave and/or one or more pulleys, such as diverter pulleys.

The measurement system comprises a source of electromagnetic radiation 120 and a sensor arrangement 130 comprising a plurality of sensors as is described in the forthcoming description. The sensor arrangement 130 is arranged to receive at least part of the radiation from the source of electromagnetic radiation 120 so that the at least three elevator ropes 110 of the rope assembly may be monitored to. The measurement system is arranged so that the at least three elevator ropes 110 travel through the radiation beam so that a projected image of the at least three ropes 110 may be generated on dedicated sensors of the ropes 110 in order to generate detections on sensing elements of the sensors of the sensor arrangement 130. In the non-limiting example of Figure 1 the measurement system is arranged to monitor four ropes, but the number of ropes is not limited in any manner as long as the number is at least three. The sensor type in the sensor arrangement 130 is selected in accordance with the electromagnetic radiation generated by the source 120, but as a non-limiting examples a sensor based on CCD technology and a sensor based on CMOS technology may be mentioned to. For example, the electromagnetic radiation generated by the source 120 may be visible light, infrared, laser, or anything similar. The source of the electromagnetic radiation 120 may further comprise other entities, such as lens, collimators, and so on, to modify the electromagnetic radiation so that it may be applied to in the measurement system. For sake of clarity it is also worthwhile to mention that the radiation may be generated with one or more radiation source in the entity referred with 120 in the enclosed figures. In a preferred embodiment each elevator rope 110 is arranged to be monitored with a dedication source of radiation and a sensor so as to generate a dedicated beam for each rope 110. In accordance with an implementation, the control unit 140 may be arranged to control of a generation of the radiation beam(s) from the source 120, e.g. by generating a control signal to the source of electromagnetic radiation 120, as well as reading of a measurement data from the sensor arrangement 130 as well as analyzing the measurement data. For example, the control unit 140 may be arranged to generate a representation of the elevator ropes 110 from the measurement data received from the sensor arrangement 130 and e.g. analyze the condition of elevator ropes 110 based on that. For example, a diameter of the elevator ropes 110 may be monitored. The mentioned entities, and other possible entities, may be communicatively coupled to each other with an applicable data bus. The data bus is preferably suitable for transferring data fast enough to monitor the condition of the elevator e.g. in a normal use speed of the elevator. For sake of completeness it is worthwhile to mention that the control unit 140 may reside locally at the site the other entities of the measurement system reside, or it may be at a remote location, such as at a data centre. Still further, due to an operating environment of the measurement system it may be provided with one or more protection covers e.g. attached on the source of the radiation 120 and/or on the sensor arrangement 130 to prevent access of dirt to the respective entities. Such a protection cover may be replaceable. For avoidance of doubt Figure 2 illustrates schematically the elevator system relevant in relation to the present invention from a top view perspective. Figure shows in an exemplifying manner how the elevator ropes 110 are arranged to travel between the source of the electromagnetic radiation 120 comprising a plurality of radiation sources 210, e.g. one for each elevator rope 110 under monitoring, and the sensor arrangement 130. In other words, at least part of the generated electromagnetic radiation is arranged to reach the sensor arrangement 130 in order to generate measurement data for evaluating a condition of the elevator ropes 110, such as diameters of the respective ropes 110. Figure 2 also discloses how the mounting of the sensor side may be arranged. Namely, the mounting of the sensors and, thus, the sensor arrangement 130, may be arranged by using a mounting bracket 220 designed for the task. The mounting bracket 220 may comprise mounting means, such as holes and similar, into which the sensor arrangement may be mounted to in a desired position with respect to each other. The mounting of the mounting bracket 220 may e.g. be done to a machinery body or bedplate beams so that the plurality of elevator ropes 110 may be arranged to run in manner allowing the monitoring of them. Advantageously, the mounting bracket 220 is implemented so that the sensor elements are rotatable with respect to mounting points because such an implementation allows to adjust the positions of the sensors optimally even in situations in which the monitored elevator ropes 110 are arranged to travel in an angle deviating from a vertical direction (cf. e.g. points P2 and P3 in Figure 5). Figure 2 also illustrates that the mounting bracket 220 may also comprise a slot into which a protection cover 230 may be installed to protect the sensor arrangement 130 from dirt. Such a protection cover 230 is made of material allowing at least a part of the radiation to travel through it. For example, the material may be glass or plastics. The installing of the protection cover 230 into the mounting bracket 220 may be arranged so that that the protection cover 230 is slid into its position. Such an approach has an advantage that the whole sensor arrangement 130 may be protected with one entity and the replacement of the protection cover is achieved in an easy manner. Generally speaking, the elevator ropes 110 are typically with a diameter from 4 mm to 22 mm. A pitch distance, i.e. a distance between centerlines of the neighboring ropes 110, is arranged between 2 mm to 50 mm. The distance is defined by an entity over which the ropes 110 are arranged to travel, cf. e.g. rope grooves in a traction shave or in a diverter pulley, or in any other pulley. In order to meet the arrangement as described an optical reading width of the sensors may be arranged to vary as per a rope 110 diameter or can kept as fixed over variety of diameters. In addition to that, tolerances are needed to be taken into account on the top of diameter(s) of the ropes 110. The total tolerance preferably consists of an assembly tolerance(s), an installation tolerance(s) and a width of rope 110 vibration amplitude. This results that sensor width shall be larger than the rope diameter.

In view of the above, the present invention at least aims to provide a solution for efficient and cost-effective sensor arrangement 130. Especially in a situation where the pitch distance of the ropes 110 is less than a mechanical width of a sensor, i.e. the width of the sensor housing, also known as sensor body and the number of parallel ropes is three or more, the sensors shall be arranged in a novel way to gain the measurement data from a plurality of elevator ropes 110. This is especially true when the goal is to install sensor so that the centerline of the respective rope 110 in the travel direction of the rope 110 is substantially in a middle of a sensing area of the sensor. In accordance with the invention the sensor arrangement 130 comprises a dedicated sensor for each of the at least three parallelly arranged elevator ropes 110 for obtaining measurement data descriptive of each respective elevator rope 110. In other words, for each elevator rope 110 in the rope assembly a respective sensor is arranged in the measurement system. For example, in case of three elevator ropes 110 in the rope assembly three sensors are included in the measurement system. In the elevator system according to the present invention each of the dedicated sensors (i.e. rope specific sensors) is arranged parallelly in part in a travel direction of the parallelly arranged elevator ropes 110 with at least one other dedicated sensor (i.e. rope specific sensor). In other words, the at least three elevator ropes 110 arranged to travel substantially parallelly along the same imaginary plane are monitored so that measurement data is gathered from each of the at least three elevator ropes 110 with the dedicated sensors, each of which is positioned so that they generate the measurement data descriptive of a condition of the respective elevator rope 110 As said, in accordance with the present invention the sensors are positioned with respect to each other so that each of them is in parallel in part in the travel direction of the substantially parallelly arranged elevator ropes 110 with at least one other dedicated sensor. Thus, the term parallel shall be understood to mean a situation wherein projections of the sensors in the traveling direction of the ropes 110 intersect partly. The term sensor shall be understood to refer to the structure of the respective sensors wherein sensing elements in the sensors extend over the width, aka. a diameter, of at least one elevator rope 110 wherein any tolerances in the position the sensor is installed for the measurement and the estimated variation of the elevator rope 110 are also taken into account. Naturally, in order to receive the radiation from the source 120 the sensors are positioned so that the sensing elements may receive at least part of the radiation from the source 120. This is achieved by arranging the sensors so that the sensing elements of each of the sensors face the parallelly arranged elevator ropes 110 at least in an angle enabling a receipt of the radiation for generating the measurement data descriptive of a condition of the respective rope 110.

Figures 3A, 3B, and 3C illustrate schematically some examples of arranging the sensors 310 in a manner described in the foregoing description. In each Figures 3A-3C a rope assembly comprising three elevator ropes 110 is illustrated, but as said the same principle is applicable in any rope assembly comprising even more elevator ropes 100 than three. Thus, the application of the present invention is not anyhow limited to the number of elevator ropes 110 shown in Figures 3A-3C as long as there are at least three elevator ropes 110 in the rope assembly. Figure 3A discloses an example of an implementation of the present invention in which a plurality of sensors 310 are arranged so that each sensor 310 is arranged to generate measurement data descriptive on a condition of respective elevator rope 110. Due to the width of the elevator ropes 110 and the pitch distance compared to the size of the sensors 310 it is not possible to position the sensors 310 only in one line, or row, and, therefore, the sensors 310 are arranged on two lines as shown in Figure 3A substantially transversally, i.e. in a right angle, with respect to the travel direction of the elevator ropes 110. As a result, each of the dedicated sensors 310 is parallel in part in the travel direction of the elevator ropes 110 with at least one other dedicated sensor 310.

Figure 3B, in turn, discloses an embodiment in which the sensors 310 are arranged parallel in part by positioning them on the same line but in a slanted position, i.e. in a predefined mounting angle (marked with a (alfa) in Figure 3B), with respect to the travel direction of the elevator ropes 110. The mounting angle may e.g. be between 15 to 75 degrees, typically between 30-60 degrees. The applied angle may be selected so that the sensing elements of the respective sensor 310 runs over the width of the elevator rope 110 in the installation angle wherein the angle shall take into account any required tolerance. In other words, also in the implementation of Figure 3B each sensor 310 extends over the respective elevator rope 110 and as a result a part of each sensor 310 is in parallel with at least one other sensor 310 in the travel direction of the elevator ropes 110.

Figure 3C illustrates a further option in accordance with the present invention to arrange the sensor 310 in the defined manner. In the option shown in Figure 3C the sensors 310 are arranged on three lines, e.g. in case the size of the sensor bodies 310 does not allow to position them in two lines. As a result, each of the dedicated sensors 310 is arranged parallelly in part with at least one other dedicated sensor 310 in the travel direction of the elevator ropes 110. As derivable from Figure 3C it may be arranged that even more than two sensors 310 are parallelly in part with respect to each other in the travel direction of the elevator ropes 110.

As mentioned in the foregoing description the examples shown in Figures 3A- 3C are non-limiting and the inventive idea as defined in the independent claims allows an introduction of further implementations.

For sake of clarity, Figure 4 is referred herein in which it is disclosed an example of a structure of the sensor 310. As mentioned, the sensor 310 comprises, among other entities, a number of sensing elements 410 wherein the sensing elements 410 may be considered to comprise one or more structures implemented in a semiconductor material which form pixels that are read in order to generate the measurement data. As said, the sensing elements 410 of a sensor 310 shall extend over the elevator rope(s) monitored with the sensor 310 in question in order to generate measurement data from which conclusions may be done. The sensing elements, and, thus, the sensor 310 may advantageously be implemented as implementing so-called line scanning method in order to optimize the amount of data collected from the measurement.

In addition, the sensor 310 is advantageously equipped with necessary hardware and software allowing at least reading of the pixel data in a manner required by the application field. Since the monitoring of the elevator ropes 110 occurs during a travel of the elevator car, i.e. when the elevator ropes 110 move in the measurement system it generates a remarkable amount of data in a high data speed. Thus, in accordance with an embodiment of the invention the sensor 310 is advantageously equipped with a memory having enough capacity to store the amount of data in a high writing speed in order to meet the requirements of the application environment. The data, i.e. the raw data, stored in the memory may be transferred to the control unit 140 for analysis at another instant of time, such as when the elevator car is stopped. In accordance with another embodiment the measurement data may be directly transferred to the control unit 140 and in this kind of approach it is necessary to arrange that the data transfer occurs at a necessary speed in order to meet the requirements of the application area.

Figure 5 illustrates at least some applicable locations for the measurement system in the elevator system. In other words, the positions referred with P1 , P2, P3, and P4 refer to advantageous locations to arrange the measurement of the condition of the plurality of the elevator ropes 110. In practice, the locations P1 , P2, P3, P4 refer to installation positions of the source of the electromagnetic radiation 120 and the sensor arrangement 130 in order to gather measurement data from which conclusions on the condition of the elevator ropes 110 may be performed. The elevator ropes 110 in Figure 5 are suspension ropes arranged to travel at least over a traction sheave 510, but further pulleys, such as a bedplate pulley or any diverter pulley may also be arranged for the respective elevator ropes 110. The other pulley referred with 520 in Figure 5 may be considered as the bedplate pulley and due to that the elevator ropes 110 travel to the counter-weight through the bedplate pulley 520 causing the maximum tension to the elevator ropes 110, a first optimal location for the installation of the measurement system for collecting measurement data is beneath the bedplate pulley 520 as denoted with P1 in Figure 5. Another advantage of the location P1 is that almost an entire length of the elevator ropes 110 travel through the point P1 , and, therefore, the location P1 is optimal for the use. The locations referred with P2 and P3 in Figure 5, i.e. between the traction sheave 510 and the bedplate pulley 520 are also good, especially arranged so that the measurement point is as close as possible from either one of the entities. This is because the tensions of the ropes 110 are also high at the locations P2 and P3, as in the location P1 , but also the vibrations of the ropes 110 is at a low level at least in most of the situations. This is because the counter-weight having a fixed weight causes the maximum tension to the ropes under monitoring. A possible location is also at the point denoted with P4 in Figure 5, i.e. beneath the traction sheave at the elevator car side even though the challenge here is that a changing load of the car affects the characteristics of the elevator ropes 110, such as the diameter, which needs to be evaluated and filtered at least to some extent to maintain an accuracy of the measurement. Worthwhile to mention that the location of the measurement in a context of the compensation ropes and the overspeed governor rope(s) shall correspond to the locations referred with P2 and P3 in Figure 5, i.e. close to respective pulleys and between the rope section between the pulleys.

Figure 6 illustrates schematically an example of a pulley, such as a traction sheave 510, into which it is arranged grooves (cf. ref. 610 for one groove) defining a pitch distance (referred with A in Figure 6) of the plurality of elevator ropes 110. In the non-limiting example as shown in Figure 6 the pitch distances are the same, but it is also possible to arrange them to vary with respect to each other. In advantageous embodiments of the invention the sensors 310 are selected so that their width at least exceeds the pitch distance A of two adjacent elevator ropes 110 in order to confirm that the sensing elements 410 of the sensors 310 extend over a width of at least one elevator rope 110 in a position installed for the measurement.

The specific examples provided in the description given above should not be construed as limiting the applicability and/or the interpretation of the appended claims. Lists and groups of examples provided in the description given above are not exhaustive unless otherwise explicitly stated.