TECHNICAL FIELD

The invention concerns in general the technical field of elevators. Especially the invention concerns elevator roping arrangements.

BACKGROUND

Elevator systems typically comprises elevator roping arrangements, such as a hoisting roping arrangement, an overspeed governor (OSG) roping arrangement, a rescue roping arrangement and/or a stalling detection roping arrangement. The elevator roping arrangements are one of typical periodical maintenance checking target of the elevator system. The elevator roping arrangements are typically elongating during their lifetime and thus the elevator roping arrangements are needed to be adjusted, e.g. shortened, during the rope lifetime, especially in case of longer travel elevator systems. The adjustment of the elevator roping arrangements may be performed during maintenance visits.

The elevator roping arrangement typically comprises a tensioner element for maintaining the tension of the elevator roping arrangement. The tensioner element may comprise a movable part that may be moving due to the elongation of the elevator roping arrangement to compensate the elongation and to maintain the tension of the elevator roping arrangement. Alternatively or in addition, the movable part of the tensioner element may be moving due to an abnormal situation, e.g. a stalling situation. The tensioner elements may typically comprise one or more limit switches, e.g. safety contacts, which are opening a safety circuit and stopping the movement of the elevator car, when the movement of the tensioner element is reaching a safety limit due to the elongation of the elevator roping arrangement and/or the abnormal situation. Result of this is a call-out, which may be prevented only by checking the elongation of the elevator roping arrangement during the maintenance visit.

Therefore, there is a need to develop further solutions for monitoring the elevator roping arrangements and/or the tensioner elements of the elevator roping arrangements. 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 objective of the invention is to present a monitoring arrangement, a method, and an elevator system for obtaining movement data of a tensioner element of an elevator roping arrangement. Another objective of the invention is that the monitoring arrangement, the method, and the elevator system for obtaining movement data of a tensioner element of an elevator roping arrangement enables providing continuously information about the tensioner element of the elevator roping arrangement.

The objectives of the invention are reached by a monitoring arrangement, a method, and an elevator system as defined by the respective independent claims.

According to a first aspect, a monitoring arrangement for obtaining movement data of a tensioner element of an elevator roping arrangement is provided, wherein the monitoring arrangement comprises: an inductive displacement sensor device associated with the tensioner element, and a monitoring system communicatively coupled to the inductive displacement sensor device, wherein the inductive displacement sensor device is configured to: obtain movement data representing a movement of a movable part of the tensioner element in relation to a fixed reference point in the tensioner element, and provide the obtained movement data to the monitoring system.

The monitoring system may further be configured to: detect one-directional long-term movement based on the movement data, wherein the detected onedirectional long-term movement may indicate an elongation of the elevator roping arrangement; and/or detect sudden movement based on the movement data, wherein the detected sudden movement may indicate an abnormal event. The monitoring system may further be configured to: detect that the onedirectional long-term movement meets a predefined first limit, and generate a preventive maintenance request comprising an instruction to adjust the length of the elevator roping arrangement.

Alternatively or in addition, the monitoring system may further be configured to: detect that the sudden movement meets a predefined second limit, and generate a control signal indicating the detection of the abnormal situation, wherein the control signal may comprise an instruction to stop a movement of an elevator car associated with the elevator roping arrangement.

The inductive displacement sensor device may be configured to use induced eddy currents in a conductive counter area on the tensioner element to provide the movement data.

The conductive counter area may be a surface of the tensioner element, a discrete conductive plate arranged to the tensioner element, a conductive coating arranged to the tensioner element, or a conductive structure arranged to the tensioner element.

The movement data may comprise position change data in relation to the fixed reference point in the tensioner element.

The conductive counter area may be a shaped conductive surface having a variable dimension in the width direction, wherein the width direction may be the direction substantially perpendicular to the movement direction of the movable part of the tensioner element.

Alternatively, the movement data may comprise data representing a change of the width of the shaped conductive surface.

The elevator roping arrangement may comprise at least an overspeed governor (OSG) roping arrangement.

The tensioner element may comprises: a tension weight of the OSG roping arrangement arranged to a bottom of an elevator shaft or a top of the elevator shaft, or a spring-based tensioner device of the OSG roping arrangement arranged to the bottom of the elevator shaft. Alternatively or in addition, the elevator roping arrangement may comprise at least a hoisting roping arrangement and a second roping arrangement, wherein the second roping arrangement may comprise: a rescue roping arrangement and/or a stalling detection roping arrangement, or a combined rescue and stalling detection roping arrangement.

The tensioner element may comprise: a tension weight of the second roping arrangement arranged to a bottom of an elevator shaft, or a spring-based tensioner device of the second roping arrangement arranged to an elevator car.

The monitoring system may be a local monitoring system or a remote monitoring system.

According to a second aspect, a method for obtaining movement data of a tensioner element of an elevator roping arrangement is provided, wherein the method comprises: obtaining, by an inductive displacement sensor device, movement data representing a movement of a movable part of the tensioner element in relation to a fixed reference point in the tensioner element, wherein the inductive displacement sensor device is associated with the tensioner element; and providing, by the inductive displacement sensor device, the obtained movement data to a monitoring system communicatively coupled to the inductive displacement sensor device.

The method may further comprise: detecting, by the monitoring system, onedirectional long-term movement based on the movement data, wherein the detected one-directional long-term movement indicates an elongation of the elevator roping arrangement; and/or detecting, by the monitoring system, sudden movement based on the movement data, wherein the detected sudden movement indicates an abnormal event.

The method may further comprise: detecting, by the monitoring system, that the one-directional long-term movement meets a predefined first limit; and generating, by the monitoring system, a preventive maintenance request comprising an instruction to adjust the length of the elevator roping arrangement.

Alternatively or in addition, the method may further comprise: detecting, by the monitoring system, that the sudden movement meets a predefined second limit; and generating, by the monitoring system, a control signal indicating the detection of the abnormal situation, wherein the control signal comprises an in- struction to stop a movement of an elevator car associated with the elevator roping arrangement.

The inductive displacement sensor device may be using induced eddy currents in a conductive counter area on the tensioner element to provide the movement data.

The movement data may comprise position change data in relation to the fixed reference point in the tensioner element.

The conductive counter area may be a shaped conductive surface having a variable dimension in the width direction, wherein the width direction may be the direction substantially perpendicular to the movement direction of the movable part of the tensioner element.

Alternatively, the movement data may comprise data representing a change of the width of the shaped conductive surface.

The monitoring system may be a local monitoring system or a remote monitoring system.

According to a third aspect, an elevator system is provided, wherein the elevator system comprises: an elevator car; a counterweight; an elevator roping arrangement associated with at least one of the elevator car and the counterweight; a tensioner element of the elevator roping arrangement; and the monitoring arrangement discussed above.

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 1A illustrates schematically an example of an elevator system comprising an arrangement for obtaining movement data of a tensioner element of an elevator roping arrangement.

Figures 1 B and 1C illustrate schematically non-limiting examples of a conductive counter area implemented as a shaped conductive surface.

Figures 2A to 2C illustrate schematically an example implementation of an inductive displacement sensor device associated with a tensioner element of an OSG roping arrangement.

Figures 3A to 3C illustrate schematically another example implementation of an inductive displacement sensor device associated with a tensioner element of an OSG roping arrangement.

Figures 4A to 4C illustrate schematically yet another example implementation of an inductive displacement sensor device associated with a tensioner element of an OSG roping arrangement.

Figures 4D and 4E illustrate schematically non-limiting examples of a conductive counter area implemented as a shaped conductive surface in the example implementation of Figures 4A to 4C.

Figures 5A to 5C illustrate schematically an example implementation of an inductive displacement sensor device associated with a tensioner element of a second roping arrangement.

Figures 5D and 5E illustrate schematically non-limiting examples of a conductive counter area implemented as a shaped conductive surface in the example implementation of Figures 5A to 5C.

Figures 6A to 6C illustrate another example implementation of an inductive displacement sensor device associated with a tensioner element of a second roping arrangement. Figure 7 illustrates schematically an example of a method for obtaining movement data of a tensioner element of an elevator roping arrangement.

Figure 8 illustrates schematically an example of components of an inductive displacement sensor device.

Figure 9 illustrates schematically an example of components of a monitoring system.

DESCRIPTION OF THE EXEMPLIFYING EMBODIMENTS

Figure 1A illustrates schematically an example of an elevator system 100 comprising a monitoring arrangement 102 for obtaining movement data of a tensioner element 104a, 104b of an elevator roping arrangement 106a, 106b, 106c. The elevator system 100 comprises an elevator car 110, a counterweight 108 and an elevator machinery configured to move the elevator car 110 along an elevator shaft 112 between a plurality of floors. The elevator machinery may comprise for example a motor and a traction sheave 114 for lifting the elevator car 110. For illustrative purposes, only the traction sheave 114 is shown in Figure 1A. The elevator system 100 may further comprise an elevator control system configured to control the operation of the elevator system 100 at least in part. The elevator system 100 may further comprise one or more known elevator entities, e.g. a safety circuit comprising a plurality of safety contacts, a door system, etc.. The elevator roping arrangement 106a, 106b, 106c may comprise a hoisting roping arrangement 106a, an overspeed governor (OSG) roping arrangement 106b, and a second roping arrangement 106c. The second roping arrangement 106c may comprise a rescue roping arrangement and/or a stalling detection roping arrangement. Alternatively, the second roping arrangement 106c may comprise a combined rescue and stalling detection rope arrangement. The elevator roping arrangement 106a, 106b, 106c may also comprise a compensation roping arrangement (for sake of clarity not shown in Figure 1A). The compensation roping arrangement may preferably be used in high-rise elevator systems. The elevator roping arrangement 106a, 106b, 106c may be implemented with any known solution, e.g. ropes or belts.

The elevator system 100 comprises further an overspeed governor (OSG) 118 configured to supervise the speed of the elevator car 110. The OSG 118 has an electrical contact, which is part of the safety circuit, and a mechanical linkage to an elevator car safety gear by the OSG roping arrangement 106b. The elevator car safety gear is a safety device that stops the movement of the elevator car 110, when the elevator car 110 is traveling at a speed that exceeds an overspeed limit set for the elevator system 100. For illustrative purposes, the elevator car safety gear is not shown in Figure 1A. Tension of the OSG roping arrangement 106b is a safety critical function defining sufficient tripping force for the OSG 118 and friction linkage and pulling force for pulling and activating the elevator car safety gear, when the OSG 118 is tripping. The tensioner element 104b (more specifically a movable part of the tensioner element 104b as will be discussed later) may be moving due to an elongation of the OSG roping arrangement 106b to compensate the elongation and to maintain the tension of the OSG roping arrangement 106b. Alternatively or in addition, the tensioner element 104b (more specifically a movable part of the tensioner element 104b as will be discussed later) may be moving due to an abnormal situation, e.g. a fault situation. The OSG 118 may for example be implemented as a fixed OSG with a moving OSG roping arrangement 106b. When the OSG 118 is implemented as the fixed OSG, the tensioner element 104b of the OSG roping arrangement 106b may for example be a tension weight arranged to a bottom of the elevator shaft 112 or to a top of the elevator shaft 112. The tension weight -based tensioner element 104b of the OSG roping arrangement 106b provides solid tension for the OSG roping arrangement 106b over the elongation of the OSG roping arrangement 106b. Alternatively, the OSG 118 may for example be implemented as a moving OSG with a stationary OSG roping arrangement 106b. The moving OSG, i.e. an on-board OSG, is arranged to the elevator car 110 and thus the moving OSG entity is moving with the elevator car 110. When the OSG 118 is implemented as the moving OSG, the tensioner element 104b of the OSG roping arrangement 106b may for example be a spring-based tensioner device arranged to the bottom of the elevator shaft 112. In the example of Figure 1A, the OSG 118 is implemented as the moving OSG with the stationary OSG roping arrangement 106b.

The elevator car 110, the machinery and the counterweight 108 are interconnected via the hoisting roping arrangement 106a routed via a plurality of pulleys 116a, 116b, 116c, and the traction sheave 114. When the traction sheave 114 rotates, the elevator car 110 and the counterweight 108 are moving. If the hoisting roping arrangement 106a comprises plurality of hoisting ropes, hoisting roping tensioner may be arranged at the end of the hoisting roping ar- rangement 106a to balance the load of the plurality of hoisting ropes. As discussed above, the elevator roping arrangement 106a, 106b, 106c may further comprise the rescue roping arrangement 106c. The rescue roping arrangement 106c is installed between the elevator car 1 10 and the counterweight 108 and is routed via the pulley 116d. The rescue roping arrangement 106c is rigidly fixed to the counterweight 108. The rescue roping arrangement 106c may be fixed to the elevator car 110 by means of the tensioner element 104a of the rescue roping arrangement 106c and routed via the pulley 116d. Alternatively, the rescue roping arrangement 106c may be rigidly fixed to the elevator car 110 and routed via a combined pulley and tensioner element 116d, 104a of the rescue roping arrangement 106c. The rescue roping arrangement 106c enables to move the elevator car 110 and the counterweight 108 from a pit of the elevator shaft 112, when the elevator system 100 is in a balance situation without energy, e.g. in case of a network break where only manual brake opening is available, or is not possible to move to the lighter direction due to safety devices. When the suspension roping arrangement 106a and/or the rescue roping arrangement 106c elongates, the tensioner element 104a of the rescue roping arrangement 106c (more specifically a movable part of the tensioner element 104a as will be discussed later) is moving due to an elongation of suspension roping arrangement 106a and/or the rescue roping arrangement 106c to compensate the elongation and to maintain the tension of the suspension roping arrangement 106a and/or the rescue roping arrangement 106c. Alternatively or in addition, the tensioner element 104a (more specifically a movable part of the tensioner element 104a as will be discussed later) may be moving due to an abnormal situation, e.g. a fault situation. The tensioner element 104a of the rescue roping arrangement 106c may for example be a tension weight arranged to the bottom of the elevator shaft 112. Alternatively, the tensioner element 104a of the rescue roping arrangement 106c may for example be a spring-based tensioner device arranged to the elevator car 110.

As discussed above, the elevator roping arrangement 106a, 106b, 106c may alternatively or in addition comprise the stalling detection roping arrangement. Alternatively, the elevator roping arrangement 106a, 106b, 106c may comprise the combined rescue and stalling detection rope arrangement. The stalling detection roping arrangement and the combined rescue and stalling detection roping arrangement may be installed between the elevator car 110 and the counterweight 108 and is routed via the pulley 116d for example similarly as discussed above referring to the rescue rope arrangement 106c. For sake of clarity only one roping arrangement 106c and the tensioner device 104a of said one roping arrangement 106c are illustrated in Figure 1A, but the same reference signs 106c and 104a are used for the rescue rope arrangement and its tensioner device, the stalling detection roping arrangement and its tensioner device, and the combined rescue and stalling detection roping arrangement and its tensioner device. The stalling detection roping arrangement 106c together with a stalling detector, e.g. a safety contact, arranged to the tensioner element 104a of the stalling detection roping arrangement 106c may be used to detect a stalling situation. In the stalling situation one of the following: the elevator car 110 or the counterweight 108 continues climbing upwards, e.g. due to high friction on the traction sheave 114, while the movement of the other one of the following: the elevator car 110 or the counterweight 108 is stopped due to stall or driving into end buffers. The tensioner element 104a of the stalling detection roping arrangement 106c or the combined rescue and stalling detection roping arrangement 106c (more specifically a movable part of the tensioner element 104a as will be discussed later) may be moving due the stalling situation or other abnormal situation. Alternatively, when stalling detection roping arrangement 106c or the combined rescue and stalling detection roping arrangement 106c elongates, the tensioner element 104a (more specifically a movable part of the tensioner element 104a as will be discussed later) may be moving due to an elongation of the stalling detection roping arrangement 106c or the combined rescue and stalling detection roping arrangement 106c to compensate the elongation and to maintain the tension of the stalling detection roping arrangement 106c or the combined rescue and stalling detection roping arrangement 106c. The tensioner element 104a of the stalling detection roping arrangement 106c or the combined rescue and stalling detection roping arrangement 106c may for example be a tension weight arranged to the bottom of the elevator shaft 112. Alternatively, the tensioner element 104a of the stalling detection roping arrangement 106c or the combined rescue and stalling detection roping arrangement 106c may for example be a spring-based tensioner device arranged to the elevator car 110. In case the elevator roping arrangement 106a, 106b, 106c comprises also the compensation roping arrangement, a compensator tensioner element may be arranged to the pit of the elevator shaft 112 for the compensation roping arrangement. The monitoring arrangement 102 for obtaining the movement data of the tensioner element 104a, 104b of the elevator roping arrangement 106a, 106b, 106c comprises an inductive displacement sensor device 120 associated with the tensioner element 104a, 104b of the elevator roping arrangement 106a, 106b, 106c, and a monitoring system 130 communicatively coupled to the inductive displacement sensor device 120. The communication between the inductive displacement sensor device 120 and the monitoring system 130 may be based on one or more known communication technologies, either wired or wireless. In the case of wireless communication, the wireless communication may happen directly between a communication beacon embedded in or connected to the inductive sensor device 120 and a corresponding communication beacon at the monitoring system 130. Alternatively, a wireless network between these communication nodes may be a mesh network or a string of plurality of communication nodes. The inductive displacement sensor device 120 may be mains powered. Alternatively, the inductive displacement sensor device 120 may be battery operated. In case of the inductive displacement sensor device 120 is battery operated, the inductive displacement sensor device 120 comprises at least one battery for powering the inductive displacement sensor device 120. The monitoring system 130 may be a local monitoring system or a remote monitoring system. The monitoring system 130 implemented as the local monitoring system may for example comprise one or more entities locating in the elevator system 100 or in association with the elevator system 100, e.g. one or more entities of the elevator control system and/or any other one or more monitoring entities that may be arranged in association with the elevator system 100. The monitoring system 130 implemented as the remote monitoring system may for example comprise one or more entities locating remotely from the elevator system 100, e.g. a remote monitoring and diagnostic system, a remote monitoring server, a service center, a data center, a server, and/or a cloud server. In the example of Figure 1A the inductive displacement sensor device 120 is associated with the tensioner element 104b of the OSG roping arrangement 106b for obtaining movement data of the tensioner element 104b of the OSG roping arrangement 106b. The inductive displacement sensor device 120 may alternatively be associated with the tensioner element 104a of the second roping arrangement 104a as will be described later in this application. The tensioner element 104a, 104b comprises a movable part 202, 402, 502, 602 that is movable in relation to a fixed reference point in the tensioner element 104a, 104b. The tensioner element 104a, 104b comprises further a stationary part 204, 404, 504, 604. The fixed reference point is fixed from the perspective of the stationary part 204, 404, 504, 604. The fixed reference point may for example be the stationary part 204, 404, 504, 604 of the tensioner element 104a, 104b. Alternatively, the fixed reference point may for example be arranged to the stationary part 204, 404, 504, 604 of the tensioner element 104a, 104b.

The inductive displacement sensor device 120 is configured to obtain movement data representing a movement of the movable part 202, 402, 502, 602 of the tensioner element 104a, 104b in relation to the fixed reference point in the tensioner element 104a, 104b. The inductive displacement sensor device 120 may be configured to obtain the movement data continuously. Alternatively, the inductive displacement sensor device 120 may obtain the movement data intermittently (e.g. at predefined time intervals). Alternatively, the inductive displacement sensor device 120 may be configured to obtain the movement data on-demand, for example in response to receiving a request from the monitoring unit 130, wherein the request may comprise a request to obtain the movement data. The inductive displacement sensor device 120 may be configured to use induced eddy currents in a conductive counter area 140 on the tensioner element 104a, 104b to obtain the movement data. For illustrative purposes the conductive counter area 140 is not shown in Figure 1A. The conductive counter area 140 may be on the movable part of 202, 402, 502, 602 of the tensioner element 104a, 104b or on the stationary part 204 of the tensioner element 104a, 104b depending on whether the inductive displacement sensor device 120 or the conductive area 140 is arranged stationary in relation to the fixed reference point in the tensioner element 104a, 104b. If the inductive displacement sensor device 120 is arranged stationary in relation to the fixed reference point in the tensioner element 104a, 104b, the conductive counter area 140 may on the movable part of 202, 402, 502, 602 of the tensioner element 104a, 104b. In this case, the conductive counter area 140 is movable in relation to the inductive displacement sensor device 120, when the movable part 202, 402, 502, 602 is moving in relation to the fixed reference point in the tensioner element 104a, 104b. Preferably, the inductive displacement sensor device 120 may be arranged stationary in relation to the fixed reference point in the tensioner element 104a, 104b. This enables for example easier cabling for wired connection to the inductive displacement sensor device 120 and/or powering the inductive displacement sensor device 120. For example, the inductive displacement sensor device 120 may be arranged (e.g. fixed) to the stationary part of 204 of the tensioner element 104a, 104b. Alternatively, if the conductive area 140 is arranged stationary in relation to the fixed reference point in the tensioner element 104a, 104b, the conductive counter area 140 may be on the stationary part 204 of the tensioner element 104a, 104b and the inductive displacement sensor device 120 may be arranged (e.g. fixed) to the movable part of 202, 402, 502, 602 of the tensioner element 104a, 104b so that the inductive displacement sensor device 120 is moving with to the movable part of 202, 402, 502, 602 of the tensioner element 104a, 104b. In this case, the inductive displacement sensor device 120 is movable in relation to the conductive counter area 140, when the movable part 202, 402, 502, 602 is moving in relation to the fixed reference point in the tensioner element 104a, 104b. In both options, to obtain the movement data the inductive displacement sensor device 120 may be located so that the inductive displacement sensor device 120 is capable to detect the eddy currents induced in the conductive counter area 140, when the movable part 202, 402, 502, 602 is moving in relation to the fixed reference point in the tensioner element 104a, 104b. The conductive counter area 140 may for example be a surface of the tensioner element 104a, 104b, a conductive coating arranged to the tensioner element 104a, 104b, or a conductive structure (e.g. a hole, a puncture, or a groove, etc.) arranged to the tensioner element 104a, 104b. Alternatively, the conductive counter area 140 may for example be or a discrete conductive plate (e.g. conductive line(s)) arranged to the tensioner element 104a, 104b as long as the change of inductance is zero or unipolar for the continuation of the movement of the tensioner element 104a, 104b, i.e. as long as the inductance perceived by the inductance displacement sensor device 120 does not change to negative and positive direction as the movable part 202, 402, 502, 602 of the tensioner element 104a, 104b moves to one direction. Preferably the inductance is such that it does not have zero inductance derivate for the whole movement direction. The conductive coating may be provided by painting, printing, or electro-coating the conductive coating to the tensioner element 104a, 104b. According to an example, the conductive counter area 140 may be implemented as a shaped conductive surface. The shaped conductive surface may for example have a variable dimension in the width direction Dw, e.g. a variable width. The width direction Dw may be the direction substantially perpendicular to the movement direction DM of the movable part 202, 402, 502, 602 of the tensioner element 104a, 104b. The induced eddy currents measured by the inductive displacement sensor device 120 are changing according to the varying dimension of the shaped conductive counter area 140, when the movable part 202, 402, 502, 602 of the tensioner element 104a, 104b moves in relation to fixed reference point in the tensioner element 104a, 104b. Figures 1 B and 1 C illustrates schematically non-limiting examples of the conductive counter area 140 implemented as the shaped conductive surface. Figure 1 B illustrates an example of a right triangle -shaped conductive surface 140. In this example the movement direction DM of the movable part 202, 402, 502, 602 of the tensioner element 104a, 104b is substantially vertical. Figure 1 C illustrates an example of a curved triangle -shaped conductive surface 140. In this example the movement direction DM of the movable part 202, 402, 502, 602 of the tensioner element 104a, 104b is substantially rotational movement. The movement data obtained by the inductive displacement sensor device 120 may for example comprise position change data in relation to the fixed reference point in the tensioner element 104a, 104b. If the inductive displacement sensor device 120 is arranged stationary in relation to the fixed reference point in the tensioner element 104a, 104b, the position change data may represent a change of a position of the conductive counter area 140 in relation to the fixed reference point in the tensioner element 104a, 104b. Alternatively if the conductive counter area 140 is arranged stationary in relation to the fixed reference point in the tensioner element 104a, 104b, the position change data may represent a change of a position of the inductive displacement sensor device 120 in relation to the fixed reference point in the tensioner element 104a, 104b. Alternatively or in addition, the movement data may for example comprise data representing a change of the width of the shaped conductive surface 140, if the conductive counter area 140 is implemented as the shaped conductive surface. The shaping of the conductive counter area 140 enables to obtain dedicated and accurate movement data. The obtained movement data may be in a digital format, i.e. the obtained movement data may be provided as a digital value.

The inductive displacement sensor device 120 is further configured to provide the movement data to the monitoring system 130. For example, the inductive displacement sensor device 120 may be configured to provide the movement data to the monitoring system 130 in response obtaining the movement data. Alternatively, the inductive displacement sensor device 120 may be configured to provide the movement data to the monitoring system 130 intermittently (e.g. at predefined time intervals) and/or upon detection of a predefined event (e.g. a sudden movement based on the movement data). For example, in case the inductive sensor device 120 is battery operated, a communication part 830 (e.g. the communication beacon embedded in the inductive displacement sensor device 120) of the inductive displacement sensor device 120 may be adapted to wake up to provide the measurement data intermittently or upon the detection of the predefined event. For example, in case of the detection of the sudden movement based on the movement data, the communication part 830 of the inductive displacement sensor device 120 may be woken up immediately and the measurement data provided immediately to the monitoring system 130. The obtained movement data may be stored in a memory part 850 of the inductive displacement sensor 120. A processing part 820 of the inductive sensor device 120 may be configured to perform preprocessing (e.g. EDGE- processing) of the obtained movement data. The monitoring system 130 may be configured to monitor the movement data obtained from the inductive displacement sensor device 120 in order to detect one or more events, e.g. elongation of the elevator roping arrangement 106a, 106b, 106c and/or abnormal events.

For example, the monitoring system 130 may be configured to detect onedirectional long-term movement based on the movement data. The detected one-directional long-term movement of the movable part 202, 402, 502, 602 of the tensioner element 104a, 104b may indicate the elongation of the elevator roping arrangement 106a, 106b, 106c. The elevator roping arrangement 106a, 106b, 106c may elongate during the lifetime of the elevator roping arrangement 106a, 106b, 106c. The elongation of the elevator roping arrangement 106a, 106b, 106c may be slowly advancing e.g. during days, weeks, months, and years. The elongation of the elevator roping arrangement 106a, 106b, 106c causes the one-directional long-term movement of the movable part 202, 402, 502, 602 of the tensioner element 104a, 104b that may be detected by the monitoring system 130 based on the movement data obtained from the inductive displacement sensor device 120.

Alternatively or in addition, the monitoring system 130 may for example be configured to detect sudden movement based on the movement data. The de- tected sudden movement of the movable part 202, 402, 502, 602 of the tensioner element 104a, 104b may indicate an abnormal event. The abnormal event may for example be the stalling situation or a fault situation. The fault situation may for example be braking of the elevator roping arrangement 106a, 106b, 106c. In the abnormal event the sudden movement may be to either direction. The sudden movement may occur for example in less than 1 second. Alternatively or in addition, the sudden movement may be fast evolving.

According to an example, the monitoring system 130 may further be configured to detect that the one-directional long-term movement meets a predefined first limit. The tensioner element 104a, 104b may comprise a safety contact for elongation detection configured to open the safety circuit to stop the movement of the elevator car 110, when the movement of the tensioner element 104a, 104b due to the elongation of the elevator roping arrangement 106a, 106b, 106c reaches an elongation safety limit. The predefined first limit may be defined so that the detection that the one-directional long-term movement meets the predefined first limit may be done before an activation of the safety contact for the elongation detection. This enables that the elongation may be detected before the movement of the elevator car 110 is stopped by the safety contact. In response to the detection that the one-directional long-term movement meets the predefined first limit, the monitoring system 130 may be configured to generate a preventive maintenance request comprising an instruction to adjust the length of the elevator roping arrangement 106a, 106b, 106c. The preventive maintenance request may for example be generated to service personnel.

Alternatively, according to another example, the monitoring system 130 may further be configured to detect that the sudden movement meets a predefined second limit. The tensioner element 104a, 104b may comprise a safety contact for abnormal situation detection configured to open the safety circuit to stop the movement of the elevator car 110, when the movement of the tensioner element 104a, 104b due to the abnormal situation reaches an abnormal situation safety limit. The predefined second limit may be defined so that the detection that the sudden movement meets the predefined second limit may be done before an activation of the safety contact for abnormal situation detection. This enables that the abnormal situation may be detected before the movement of the elevator car 110 is stopped by the safety contact. In response to the detection that the sudden movement meets the predefined second limit, the mon- itoring system 130 may be configured to generate a control signal indicating the detection of the abnormal situation. The control signal may comprise an instruction to stop a movement of the elevator car 110 associated with the elevator roping arrangement 106a, 106b, 106c. The control signal may for example be generated to the elevator control system.

The verb "meet" in context of a predefined limit, e.g. the predefined first limit and/or the predefined second limit, is used in this patent application to mean that a predefined condition is fulfilled. For example, the predefined condition may be that the predefined limit is reached and/or exceeded.

Next some implementation examples of the inductive displacement sensor device 120 of the monitoring arrangement 102 for obtaining movement data of different tensioner elements 104a, 104b of different elevator roping arrangements 106a, 106b, 106c are discussed referring to Figures 2A to 2C, 3A to 3C, 4A to 4E, 5A to 5E and 6A to 6D. The inductive displacement sensor device 120 of the monitoring arrangement 102 may alternatively or in addition be used to obtain movement data of any other tensioner elements of the elevator roping arrangements than discussed in the following implementation examples. For example, the inductive displacement sensor device 120 of the monitoring arrangement 102 may be used to obtain movement data of the compensator tensioner element of the compensation roping arrangement and the hoisting rope tensioner of the hoisting roping arrangement 106a. In the examples of Figures 2A to 2C, 3A to 3C, 4A to 4E, 5A to 5E and 6A to 6D, the inductive displacement sensor device 120 is arranged stationary in relation to the fixed reference point in the tensioner element 104a, 104b and the conductive counter area 140 is on the movable part 202, 402, 502, 602 of the tensioner element 104a, 104b. However, the inductive displacement sensor device 120 may also be arranged to the movable part of 202, 402, 502, 602 of the tensioner element 104a, 104b and the conductive counter area 140 may be on the stationary part 204 of the tensioner element 104a, 104b and thus stationary in relation to the fixed reference point in the tensioner element 104a, 104b as discussed above.

Figures 2A to 2C illustrate an example implementation of the inductive displacement sensor device 120 associated with the tensioner element 104b of the OSG roping arrangement 106b for obtaining movement data of the tensioner element 104b of the OSG roping arrangement 106b. Figure 2A illus- trates an overall view of the OSG roping arrangement 106b. Figure 2B illustrates a closer view of the tensioner element 104b of the OSG roping arrangement 106b of Figure 2A in an initial situation. The initial situation may for example be a situation before a movement of the movable part 202 of the tensioner element 104b of the OSG roping arrangement 106b, e.g. before the elongation of the OSG roping arrangement 106b, e.g. after installation or adjustment of the OSG roping arrangement 106b. Figure 2C illustrates a closer view of the tensioner element 104b of the OSG roping arrangement 106b of Figure 2A in a second situation. The second situation may for example be an example situation after movement of the movable part 202 of the tensioner element 104b of the OSG roping arrangement 106b, e.g. after elongation of the OSG roping arrangement 106b. In the example of Figures 2A to 2C the tensioner element 104b of the OSG roping arrangement 106b is a tension weight of the OSG roping arrangement 106b. More specifically, the tensioner element 104b of the OSG roping arrangement 106b is a swing arm tension weight of the OSG roping arrangement 106b. The tensioner element 104b may be arranged to the bottom of the elevator shaft 112 as illustrated in the example of Figures 2A to 2C. Alternatively, the tensioner element 104b may be arranged to the top of the elevator shaft 112. In the example of Figures 2A to 2C the OSG 118 is implemented as the fixed OSG with the moving OSG roping arrangement 106b. The OSG 118 may be fixed to the top of the elevator shaft 112, e.g. to a guide rail 206 as illustrated in the example of Figure 2A or to a machine room. Guide rails 206 are installed vertically in the elevator shaft to guide and direct the course of travel of the elevator car 110 and the counterweight 108 along the elevator shaft 112. For illustrative purposes, only one guide rail 206 is shown in Figures 2A to 2C. Alternatively, the OSG 118 may be fixed to the bottom of the elevator shaft 112, if the tensioner element 104b is arranged to the top of the elevator shaft 112. The OSG 118 is mechanically linked to the elevator car safety gear 208 arranged to the elevator car 110 via the moving OSG roping arrangement 106b.

The tensioner element 104b of the OSG roping arrangement 106b comprises the stationary part 204 and the movable part 202 being movable in relation to the stationary part 204. The stationary part 204 may for example be fixed to the guide rail 206. The movable part 202 may comprise a swing arm part 212a and a diverter pulley part 212b for moving the OSG roping arrangement 106b. The shape of the swing arm part 212a of Figures 2A to 2C is only a non- limiting example and any other shape swing arm part may also be used. Similarly, the shape of the stationary part 204 of Figures 2A to 2C is only a nonlimiting example and any other shape stationary part 204 may also be used.

The movable part 202 of the tensioner element 104b is moving, i.e. the position of the movable part 202 of the tensioner element 104b is changing, in relation to the fixed reference point in the tensioner element 104b. For example, in the example situation of Figure 2C the movable part 202 of the tensioner element 104b of the OSG roping arrangement 106b has moved, e.g. due to the elongation of the OSG roping arrangement 106b, from the initial situation illustrated in the example of Figure 2B. One-directional long-term movement of the movable part 202 of the tensioner element 104b may be caused by elongation of the OSG roping arrangement 106b. The sudden movement of the movable part 202 of the tensioner element 104b may for example be caused by the abnormal situation, e.g. the fault situation. The inductive displacement sensor device 120 is configured to obtain the movement data representing the movement of the movable part 202 of the tensioner element 104b in relation to the fixed reference point in the tensioner element 104b. The inductive displacement sensor device 120 may be configured to obtain the movement data by measuring the induced eddy-currents in the conductive counter area 140 on the movable part 202 of the tensioner element 104b. In the example of Figures 2A to 2C the conductive counter area 140 is the surface of the movable part 202 of the tensioner element 104b. Alternatively, the conductive counter area 140 may be implemented as the conductive plate or the conductive coating arranged to the movable part 204 of the tensioner element 104b as discussed above. The movement data may for example comprise the position change data representing the change of the position of the conductive counter area 140 in relation to the fixed reference point in the tensioner element 104b. The conductive counter area 140 may alternatively implemented as the shaped conductive surface and in that case the movement data may comprise data representing the change of the width of the shaped conductive surface. In the example of Figure 2A to 2C the tensioner element 104b comprises also the safety contact 214 for the elongation detection. If the movement of the movable part 202 of the tensioner element 104b reaches the elongation safety limit, i.e. activates the safety contact 214, the safety contact is configured to open the safety circuit to stop the movement of the elevator car 110. Figures 3A to 3C illustrate another example implementation of the inductive displacement sensor device 120 associated with the tensioner element 104b of the OSG roping arrangement 106b for obtaining movement data of the tensioner element 104b of the OSG roping arrangement 106b. The example implementation of Figures 3A to 3C is otherwise similar to the example implementation of Figures 2A to 2C, but the tensioner element 104b of the OSG roping arrangement 106b is a linear tension weight of the OSG roping arrangement 106b, wherein the movable part 202 may comprise a linear arm part 312a and the diverter pulley part 212b for moving the OSG roping arrangement 106b. Therefore, the description referring to the example implementation of Figures 2A to 2C apply also to the example implementation of Figures 3A to 3C.

Figures 4A to 4C illustrate yet another example implementation of the inductive displacement sensor device 120 associated with the tensioner element 104b of the OSG roping arrangement 106b for obtaining movement data of the tensioner element 104b of the OSG roping arrangement 106b. Figure 4A illustrates an overall view of the OSG roping arrangement 106b. Figure 4B illustrates a closer view of the tensioner element 104b of the OSG roping arrangement 106b of Figure 4A in the initial situation as discussed above referring to Figure 2B. Figure 4C illustrates a closer view of the tensioner element 104b of the OSG roping arrangement 106b of Figure 4A in the second situation as discussed above referring to Figure 2C. In the example of Figures 4A to 4C the tensioner element 104b of the OSG roping arrangement 106b is a spring-based tensioner device of the OSG roping arrangement 106b. In the example of Figures 4A to 4C the OSG 118 is implemented as the moving with the stationary OSG roping arrangement 106b. The moving OSG is arranged to the elevator car 110 and moving with the elevator car 110. Furthermore, the OSG 118 is linked directly to the elevator car safety gear 208 arranged to the elevator car 110. The stationary OSG roping arrangement 106b is tensioned between a fixed end point 406 arranged to the top of the elevator shaft 112, e.g. to the guide rail 206, and the tensioner element 104b arranged to the bottom of the elevator shaft 112. The OSG 118 may comprise one or more pulleys running along the stationary OSG roping arrangement 106b.

The tensioner element 104b of the OSG roping arrangement 106b implemented as the spring-based tensioner device comprises the stationary part 404 and the movable part 402 being movable in relation to the stationary part 404. The stationary part 404 may for example be fixed to the guide rail 206. The movable part 402 may comprise a tensioning rotating plate, e.g. a tensioning rotating wheel, rotating in relation to the stationary part 404 of the tensioner element 104b. The OSG roping arrangement 106b may be routed via a diverter pulley 408 to the tensioning rotating plate to which the other end of the OSG roping arrangement 106b may be fixed. The tensioning of the OSG roping arrangement 106b by the spring-based tensioner device 104b is provided by a tensioning spring 410.

The movable part 402 of the tensioner element 104b, i.e. the tensioning rotating plate, is moving, i.e. rotating, in relation to the fixed reference point in the tensioner element 104b. For example, in the example situation of Figure 4C the movable part 402 of the tensioner element 104b of the OSG roping arrangement 106b has moved, e.g. due to the elongation of the OSG roping arrangement 106b, from the initial situation illustrated in the example of Figure 4B. One-directional long-term movement, i.e. one-directional long-term rotating movement, of the tensioning rotating plate 402 may be caused by elongation of the OSG roping arrangement 106b. In other words, when the OSG roping arrangement 106b is elongating the tensioning rotating plate 402 is rotating in relation to the fixed reference point in the tensioner element 104b in order to maintain the tension of the OSG roping arrangement 106b. Furthermore, when the OSG roping arrangement 106b is elongating the tensioning spring 410 is decompressing. The sudden movement of the movable part 402 of the tensioner element 104b may for example be caused by the abnormal situation, e.g. the fault situation. The inductive displacement sensor device 120 is configured to obtain the movement data representing the movement of the movable part 402 of the tensioner element 104b in relation to the fixed reference point in the tensioner element 104b. The inductive displacement sensor device 120 may be configured to obtain the movement data by measuring the induced eddy-currents in the conductive counter area 140 on the movable part 402 of the tensioner element 104b. In the example of Figures 4A to 4C the conductive counter area 140 is implemented as the shaped conductive surface. The shaped conductive surface 140 may be implemented as the conductive plate or the conductive coating arranged to the movable part 202 of the tensioner element 104b as discussed above. The movement data may for example comprise the position change data representing the change of the position of the conductive counter area 140 in relation to the fixed reference point in the tensioner element 104b. Alternatively or in addition, the movement data may comprise data representing the change of the width of the shaped conductive surface 140. Figures 4D illustrates a closer view of the shaped conductive surface 140 and the inductive displacement sensor device 120 measuring the width of the shaped conductive surface 140 in the initial situation illustrated in Figure 4B. Figure 4E illustrates a closer view of the shaped conductive surface 140 and the inductive displacement sensor device 120 measuring the width of the shaped conductive surface 140 in the second situation illustrated in Figure 4C. Figures 4D and 4E illustrates the change of the width of the shaped conductive surface 140 measurable with the inductive displacement sensor device 120 and caused by the movement of the movable part 402 of the tensioner device 104b in relation to the fixed reference point in the tensioner element 104b due to the elongation of the OSG roping arrangement 106b. In the example of Figure 4A to 4C the tensioner element 104b comprises also the safety contact 214 for the elongation detection. If the movement of the movable part 202 of the tensioner element 104b reaches the elongation safety limit, i.e. a triggering device 412 arranged to the tensioning rotating plate 402 activates the safety contact 214, the safety contact 214 is configured to open the safety circuit to stop the movement of the elevator car 110.

Figures 5A to 5C illustrate an example implementation of the inductive displacement sensor device 120 associated with the tensioner element 104a of the second roping arrangement 106c, for obtaining movement data of the tensioner element 104a of the second roping arrangement 106c. The second roping arrangement 106c may for example be the rescue roping arrangement, the stalling detection roping arrangement, or the combined rescue and stalling detection roping arrangement. The elevator roping arrangement of this example comprises further the hoisting roping arrangement 106a. Figure 5A illustrates an overall view of the hoisting roping arrangement 106a and the second roping arrangement 106c. Figure 5B illustrates a closer view of the tensioner element 104b of the second roping arrangement 106c of Figure 5A in an initial situation. The initial situation may for example be a situation before a movement of the movable part 502 of the tensioner element 104b of the second roping arrangement 106c, e.g. before the elongation of the hoisting roping arrangement 106a and the second roping arrangement 106c, e.g. after installation or adjustment of the hoisting roping arrangement 106a and the second roping arrangement 106, or before the abnormal event. Figure 5C illustrates a closer view of the tensioner element 104b of the second roping arrangement 106c of Figure 5A in a second situation. The second situation may for example be an example situation after the movement of the movable part 502 of the tensioner element 104b of the second roping arrangement 106c, e.g. after elongation of the hoisting roping arrangement 106a and the second roping arrangement 106c, or after occurrence of the abnormal event. In the example of Figure 5A the elevator car 110 is in the topmost floor and the counterweight 108 is in an initial position, i.e. in a position before elongation of the hoisting roping arrangement 106a. In the example of Figures 5A to 5C the second rope arrangement 106c is rigidly fixed to the counterweight 108, routed via the pulley 116d, and fixed to the elevator car 110 by means of the tensioner element 104a of the second roping arrangement 106c. In the example of Figures 5A to 5C the tensioner element 104a of the second roping arrangement 106c is a spring-based tensioner device of the second roping arrangement 106c. The spring-based tensioner device of the second rope arrangement 106c is arranged to the elevator car 110 by means of the stationary part of the tensioner element 104a.

The tensioner element 104a of the second roping arrangement 106c comprises the stationary part 504 and the movable part 502 being movable in relation to the stationary part 504. The movable part 502 may comprise a compression spring 512 to which the elevator car side end of the second roping arrangement 106c may be fixed.

The movable part 502 of the tensioner element 104a is moving, i.e. the position of the conductive counter area 140 on the movable part 502 of the tensioner element 104c is changing, in relation to the fixed reference point in the tensioner element 104a. The movement of the movable part 502 may comprise decompression of the compression spring 512 that causes increasing the height of the compression spring 512 and thus changing of the position of the conductive counter area 140 on the movable part 502 of the tensioner element 104c in relation to the fixed reference point in the tensioner element 104a, 104b. For example, in the example situation of Figure 5C the movable part 502 of the tensioner element 104a of the second roping arrangement 106c has moved, e.g. due to the elongation of the hoisting roping arrangement 106a and/or the second roping arrangement 106c, from the initial situation illustrated in the example of Figure 5B. One-directional long-term movement of the movable part 502 of the tensioner element 104a may be caused by elongation of the hoisting roping arrangement 106a and/or the second roping arrangement 106c. For example, when the hoisting roping arrangement 106a and/or the second roping arrangement 106c are elongating, the compression spring 512 of the movable part 502 of the tensioner element 104a is decompressing causing that the height of the compression spring 512 is increasing. Thus, the position of the conductive counter area 140 on the movable part 502 of the tensioner element 104a changes when the hoisting roping arrangement 106a and/or the second roping arrangement 106c are elongating. The sudden movement of the movable part 502 of the tensioner element 104a may for example be caused by the abnormal situation, e.g. the stalling situation or the fault situation. For example, when the stalling situation or the fault situation occurs, the compression spring 512 of the movable part 502 of the tensioner element 104a is suddenly decompressing causing that the height of the compression spring 512 is suddenly increasing or suddenly compressing causing that the height of the compression spring 512 is suddenly decreasing. Thus, the position of the conductive counter area 140 on the movable part 502 of the tensioner element 104a changes suddenly when the stalling situation or the fault situation occurs. The inductive displacement sensor device 120 is configured to obtain the movement data representing the movement of the movable part 502 of the tensioner element 104a in relation to the fixed reference point in the tensioner element 104a. The inductive displacement sensor device 120 may be configured to obtain the movement data by measuring the induced eddy-currents in the conductive counter area 140 on the movable part 502 of the tensioner element 104c. The conductive counter area 140 is implemented as the shaped conductive surface arranged to the movable part 502 of the tensioner element 104a. The movement data may for example comprise the position change data representing the change of the position of the conductive counter area 140 in relation to the fixed reference point in the tensioner element 104a. Alternatively or in addition, the movement data may comprise for example data representing the change of the width of the shaped conductive surface 140. Figure 5D illustrates a closer view of the shaped conductive surface 140 and the inductive displacement sensor device 120 measuring the width of the shaped conductive surface 140 in the initial situation illustrated in Figure 5B. Figure 5E illustrates a closer view of the shaped conductive surface 140 and the inductive displacement sensor device 120 measuring the width of the shaped conductive surface 140 in the second situation illustrated in Figure 5C. Figures 5D and 5E illustrates the change of the width of the shaped con- ductive surface 140 measurable with the inductive displacement sensor device 120 and caused by the movement of the movable part 402 of the tensioner device 104b in relation to the fixed reference point in the tensioner element 104a due to the elongation of the hoisting roping arrangement 106a and/or the second roping arrangement 106c or the occurrence of the abnormal situation.

Figures 6A to 6D illustrate another example of obtaining the movement data of the tensioner element 104a of the second roping arrangement 106c, wherein the second roping arrangement may be the rescue roping arrangement, the stalling detection roping arrangement, or the combined rescue and stalling detection roping arrangement 106c. The elevator roping arrangement of this example comprises further the hoisting roping arrangement 106a. Figure 6A illustrates an overall view of the hoisting roping arrangement 106a and the second roping arrangement 106c. Figure 6B illustrates a closer view of the tensioner element 104b of the second roping arrangement 106c of Figure 6A in an initial situation. The initial situation may for example be a situation before a movement of the movable part 602 of the tensioner element 104b of the second roping arrangement 106c, e.g. before the elongation of the hoisting roping arrangement 106a and the second roping arrangement 106c, e.g. after installation or adjustment of the hoisting roping arrangement 106a and the second roping arrangement 106, or before the abnormal event. Figure 6C illustrates a closer view of the tensioner element 104b of the second roping arrangement 106c of Figure 6A in a second situation. The second situation may for example be a situation after the movement of the movable part 602 of the tensioner element 104b of the second roping arrangement 106c, e.g. after elongation of the hoisting roping arrangement 106a and the second roping arrangement 106c. Figure 6D illustrates a closer view of the tensioner element 104b of the second roping arrangement 106c of Figure 6A in a third situation. The third situation may for example be a situation after the movement of the tensioner element 104b of the second roping arrangement 106c, e.g. after occurrence of the abnormal event. In the example of Figure 6A the elevator car 110 is in the topmost floor and the counterweight 108 is in an initial position, i.e. in a position before elongation of the hoisting roping arrangement 106a. In the example of Figures 6A to 6D the second rope arrangement 106c is rigidly fixed to the counterweight 108 and to the elevator car 110 and routed via the combined pulley and tensioner element 116d, 104a of the second roping arrangement 106c. In the example of Figures 6A to 6D the tensioner element 104a of the second roping arrangement 106c is a tension weight of the second roping arrangement 106c. More specifically, the tensioner element 104a of the second roping arrangement 106c is a swing arm tension weight of the second roping arrangement 106c. The tensioner element 104a may be arranged to the bottom of the elevator shaft 112 as illustrated in the example of Figures 6A to 6D.

The tensioner element 104a of the second roping arrangement 106c comprises the stationary part 604 and the movable part 602 being movable in relation to the stationary part 604. The movable part 602 may comprise a swing arm part 612a and a diverter pulley part 116d comprising two diverter pulleys 612b for moving the second roping arrangement 106c. The shape of the swing arm part 612a of Figures 6A to 6D is only a non-limiting example and any other shape swing arm part may also be used. Similarly, the shape of the stationary part 604 of Figures 6A to 6D is only a non-limiting example and any other shape stationary part 604 may also be used.

The movable part 602 of the tensioner element 104a is moving, i.e. the position of the movable part 602 of the tensioner element 104b is changing, in relation to the fixed reference point in the tensioner element 104a. For example, in the example situation of Figure 6C the movable part 602 of the tensioner element 104a of the second roping arrangement 106c has moved, e.g. due to the elongation of the hoisting roping arrangement 106a and/or the second roping arrangement 106c, from the initial situation illustrated in the example of Figure 6B. According to another example, in the example situation of Figure 6D the movable part 602 of the tensioner element 104a of the second roping arrangement 106c has moved to another direction, e.g. due to e.g. the stalling situation or the fault situation, from the initial situation illustrated in the example of Figure 6B and/or from the second situation illustrated in the example of Figure 6C. One-directional long-term movement of the movable part 402 of the tensioner element 104a may be caused by elongation of the hoisting roping arrangement 106a and/or the second roping arrangement 106c. Sudden movement of the movable part 602 of the tensioner element 104a may for example be caused by the abnormal situation, e.g. the stalling situation or the fault situation. The inductive displacement sensor device 120 is configured to obtain the movement data representing the movement of the movable part 602 of the tensioner element 104a in relation to the fixed reference point in the tensioner element 104a. The inductive displacement sensor device 120 may be configured to obtain the movement data by measuring the induced eddy-currents in the conductive counter area 140 on the movable part 602 of the tensioner element 104a. In the example of Figures 6A to 6D the conductive counter area 140 is the surface of the movable part 602 of the tensioner element 104a. Alternatively, the conductive counter area 140 may be implemented as the conductive plate or the conductive coating arranged to the movable part 602 of the tensioner element 104a as discussed above. The movement data may for example comprise the position change data representing the change of the position of the conductive counter area 140 in relation to the fixed reference point in the tensioner element 104b. The conductive counter area 140 may alternatively implemented as the shaped conductive surface and in that case the movement data may comprise data representing the change of the width of the shaped conductive surface. In the example of Figure 6A to 6D the tensioner element 104b comprises also the safety contact 214a for the elongation detection and the safety contact 214b for the abnormal situation detection. If the movement of the movable part 602 of the tensioner element 104a reaches the elongation safety limit, i.e. activates the safety contact 214a, or the abnormal safety situation limit, i.e. activates the safety contact 214b, the safety contact 214a, 214b is configured to open the safety circuit to stop the movement of the elevator car 110.

Next an example of a method for obtaining movement data of a tensioner element 104a, 104b of an elevator roping arrangement 106a, 106b, 106c is described by referring to Figure 7. Figure 7 schematically illustrates the method as a flow chart. The method may be performed by the monitoring arrangement 102 discussed above.

At a step 710, the inductive displacement sensor device 120 obtains the movement data representing the movement of the movable part 202 of the tensioner element 104a, 104b in relation to the fixed reference point in the tensioner element 104a, 104b. The inductive displacement sensor device 120 may obtain the movement data continuously. Alternatively, the inductive displacement sensor device 120 may obtain the movement data intermittently (e.g. at predefined time intervals). Alternatively, the inductive displacement sensor device 120 may be configured to obtain the movement data on- demand, for example in response to receiving a request from the monitoring unit 130, wherein the request may comprise a request to obtain the movement data. The inductive displacement sensor device 140 may use induced eddy currents in the conductive counter area 140 on the tensioner element 104a, 104b to obtain the movement data as discussed. The movement data may for example comprise the position change data in relation to the fixed reference point in the tensioner element 104a, 104b. If the inductive displacement sensor device 120 is arranged stationary to the fixed reference point in the tensioner element 104a, 104b, the position change data may represent a change of a position of the conductive counter area 140 in relation to the fixed reference point in the tensioner element 104a, 104b. Alternatively or in addition, the movement data may for example comprise data representing a change of the width of the shaped conductive surface 140, if the conductive counter area 140 is implemented as the shaped conductive surface.

At a step 720, the inductive displacement sensor device 120 further provides the movement data to the monitoring system 130 as discussed above. The monitoring system 130 may monitor the movement data obtained from the inductive displacement sensor device 120 in order to monitor one or more events, e.g. elongation of the elevator roping arrangement 106a, 106b, 106c and/or abnormal events.

For example, at a step 730 the monitoring system 130 may detect onedirectional long-term movement based on the movement data. The detected one-directional long-term movement of the movable part 202, 402, 502, 602 of the tensioner element 104a, 104b may indicate the elongation of the elevator roping arrangement 106a, 106b, 106c. As discussed above, the elongation of the elevator roping arrangement 106a, 106b, 106c causes the one-directional long-term movement of the movable part 202, 402, 502, 602 of the tensioner element 104a, 104b that may be detected by the monitoring system 130 based on the movement data obtained from the inductive displacement sensor device 120.

Alternatively or in addition, at a step 740, the monitoring system 130 may for example detect sudden movement based on the movement data. The detected sudden movement of the movable part 202, 402, 502, 602 of the tensioner element 104a, 104b may indicate an abnormal event. The abnormal event may for example be the stalling situation or the fault situation as discussed above.

According to an example, at a step 750 the monitoring system 130 may further detect that the one-directional long-term movement meets the predefined first limit. The predefined first limit may be defined so that the detection that the one-directional long-term movement meets the predefined first limit may be done before an activation of the safety contact for the elongation detection. In response to the detection that the one-directional long-term movement meets the predefined first limit at the step 750, the monitoring system 130 may generate at a step 760 a preventive maintenance request comprising an instruction to adjust the length of the elevator roping arrangement 106a, 106b, 106c. The preventive maintenance request may for example be generated to service personnel.

Alternatively, according to another example, at a step 770 the monitoring system 130 may further detect that the sudden movement meets a predefined second limit. The predefined second limit may be defined so that the detection that the sudden movement meets the predefined second limit may be done before an activation of the safety contact for abnormal situation detection. In response to the detection that the sudden movement meets the predefined second limit at the step 770, the monitoring system 130 may generate at a step 780 a control signal indicating the detection of the abnormal situation. The control signal may comprise an instruction to stop a movement of the elevator car 110 associated with the elevator roping arrangement 106a, 106b, 106c. The control signal may for example be generated to the elevator control system.

Figure 8 illustrates schematically an example of the components of the inductive displacement sensor device 120. The inductive displacement sensor device 120 may comprise a sensor part 810, a processing part 820, and a communication part 830. The inductive displacement sensor device 120 may further comprise a memory part 850. The sensor part 810 of the inductive displacement sensor device 120 may comprise an inductive coil 840 configured to observe the induced eddy currents in the conductive counter area 140 on the tensioner element 104a, 104b to obtain the movement data as described. The supply frequency of the inductive coil 840 may preferably be so high that the eddy currents do not enter deep into the conductive counter area 140. The layout of the inductive coil 840 may for example be circle, rectangular, or oval, etc. The layout of the inductive coil 840 illustrated in the example of Figure 8 is only one example layout for the inductive coil 840. However, any other layout for the inductive coil 840 may also be applied. The processing part 820 may comprise one or more processors, the memory part 850 may comprise one or more memories, and the communication part 830 may comprise one or more communication devices, e.g. the communication beacon. The mentioned ele- merits may be communicatively coupled to each other with e.g. an internal bus. The memory part 850 may store and maintain portions of a computer program (code) 855, movement data, and any other data. The computer program 855 may comprise instructions which, when the computer program 855 is executed by the processing part 820 may cause the processing part 820, and thus the inductive displacement sensor device 120 to carry out desired tasks, e.g. one or more of the method steps and/or operations of the inductive displacement sensor device 120 as described above. The processing part 820 may thus be arranged to access the memory part 850 and retrieve and store any information therefrom and thereto. For sake of clarity, the processor herein refers to any unit suitable for processing information and control the operation of the inductive displacement sensor device 120, among other tasks. The operations may also be implemented with a microcontroller solution with embedded software. Similarly, the memory part 850 is not limited to a certain type of memory only, but any memory type suitable for storing the described pieces of information may be applied in the context of the present invention. The communication part 830 provides one or more communication interfaces for communication with any other unit, e.g. the monitoring system 130, and/or one or more databases. The computer program 855 may be a computer program product that may be comprised in a tangible nonvolatile (non-transitory) computer-readable medium bearing the computer program code 855 embodied therein for use with a computer, i.e. the inductive displacement sensor device 120.

Figure 9 illustrates schematically an example of components of the monitoring system 130. The monitoring system 130 may comprise a processing unit 910 comprising one or more processors, a memory unit 920 comprising one or more memories, a communication interface unit 930 comprising one or more communication devices (e.g. the communication beacon), and possibly a user interface (III) unit 940. The mentioned elements may be communicatively coupled to each other with e.g. an internal bus. The memory unit 920 may store and maintain portions of a computer program (code) 925, the movement data, and/or any other data. The computer program 925 may comprise instructions which, when the computer program 925 is executed by the processing unit 910 of the monitoring system 130 may cause the processing unit 910, and thus the monitoring system 130 to carry out desired tasks, e.g. one or more of the method steps and/or the operations of the monitoring system 130 as described above. The processing unit 910 may thus be arranged to access the memory unit 920 and retrieve and store any information therefrom and thereto. For sake of clarity, the processor herein refers to any unit suitable for processing information and control the operation of the monitoring system 130, among other tasks. The operations may also be implemented with a microcontroller solution with embedded software. Similarly, the memory unit 920 is not limited to a certain type of memory only, but any memory type suitable for storing the described pieces of information may be applied in the context of the present invention. The communication interface unit 930 provides one or more communication interfaces for communication with any other unit, e.g. the inductive displacement sensor device 120, the elevator control system, one or more databases, or with any other unit. The user interface unit 940 may comprise one or more input/output (I/O) devices, such as buttons, keyboard, touch screen, microphone, loudspeaker, display and so on, for receiving user input and out- putting information. The computer program 925 may be a computer program product that may be comprised in a tangible nonvolatile (non-transitory) computer-readable medium bearing the computer program code 925 embodied therein for use with a computer, i.e. the monitoring system 130.

The monitoring arrangement 102 and the method described above enable continuous monitoring of the movement data of the tensioner element 104a, 104b of the elevator roping arrangement 106a, 106b, 106c. Thus, the monitoring arrangement 102 and the method enable anticipating and predicting maintenance needs and request planned maintenance visits (for example for adjusting the elevator roping arrangement 106a, 106b, 106c), already before stopping the operation of the elevator system 100 and instead off generating callout. The adjustment of the elevator roping arrangement 106a, 106b, 106c is one of the typical periodical maintenance operations in the elevator systems. The monitoring arrangement 102 and the method described above enable shortening the duration of the periodical maintenance visits, by enabling the continuous monitoring and also predicting call-outs. The inductive displacement sensor device 120 described above is a cost-effective solution for obtaining the movement data of the tensioner element 104a, 104b of the elevator roping arrangement 106a, 106b, 106c. The monitoring arrangement 102 and the method described above may provide data about elongation profile and lifetime of the elevator roping arrangement 106a, 106b, 106c for a predictive maintenance program (typically the elevator roping arrangement 106a, 106b, 106c are first elongating faster, then slower, and in end of lifetime the elevator roping arrangement 106a, 106b, 106c start to elongate again faster e.g. due to wire brakes etc.). Thus, the monitoring arrangement 102 and the method described above may also be used for lifetime monitoring of the elevator roping arrangement 106a, 106b, 106c.

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.