WO2024252061A1

WO2024252061A1 - Control of an elevator in a flooded pit

Info

Publication number: WO2024252061A1
Application number: PCT/FI2023/050340
Authority: WO
Inventors: Juha-Matti Aitamurto; Ari Kattainen
Original assignee: Kone Corp
Current assignee: Kone Corp
Priority date: 2023-06-09
Filing date: 2023-06-09
Publication date: 2024-12-12
Anticipated expiration: 2025-12-09

Abstract

A method for controlling an operation of an elevator (100) is provided, the method, performed by a safety portion (180) of a control system (165) of the elevator (100), comprises: receiving (310) measurement data; determining (320) 5 a level of water in an elevator shaft (195); determining (330) a safety limit (SL, SL1, SL2) above the level of water into which at least an elevator car (110) is allowed to travel; setting (340) a number of restrictions in relation to a movement of the elevator car (110); and generating (350) a control signal to an elevator control portion (170) of the control system (165), the control signal carrying data 10 defining the number of restrictions at least in relation to the movement of the elevator car (110) in the elevator shaft (195). Also a control system, a computer program and a computer-readable medium are provided.

Description

CONTROL OF AN ELEVATOR IN A FLOODED PIT

TECHNICAL FIELD

The invention concerns in general the technical field of elevators. More particularly, the invention concerns safety aspects of elevators.

BACKGROUND

Elevators are installed in various locations which are experiencing various types of natural phenomena. Flooding is increasingly experienced all over the world and it may occur that the water enters buildings in which elevators are operated. It is common that the water ends up to an elevator shaft and the level of water may rise to an extent that it may reside in a travel path of an elevator car and a counterweight of the elevator car. This causes safety risks with respect to a possibility to operate the elevator system and also with respect to passengers residing in the elevator car, and in the building in general. In addition to get trapped in the elevator the flooding may impact to various devices and similar in the elevator resulting as electrical faults and inoperability of the same. Thus, risks due to electric shocks, slippery surfaces, and so on are present.

There are introduced several approaches for situations the flooding hits elevator systems. For example, in a document EP1061031 A1 it is described a solution for monitoring a flood speed and to take measures with respect to an operation of the elevator in accordance with the information on the flood speed.

Due to importance of the area there is room for introducing novel approaches in order to improve safety in the field of elevators when being affected by flooding. 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 a method, a control system, a computer program and a computer-readable medium for controlling an operation of an elevator.

The objects of the invention are reached by a method, a control system, a computer program and a computer-readable medium as defined by the respective independent claims.

According to a first aspect, a method for controlling an operation of an elevator is provided, the method, performed by a safety portion of a control system of the elevator, comprises: receiving measurement data, determining a level of water in an elevator shaft of the elevator based on the measurement data, determining a safety limit above the level of water in the elevator shaft into which at least an elevator car of the elevator is allowed to travel, the safety limit is determined based on the level of water in the elevator shaft, setting a number of restrictions in relation to a movement of the elevator car in the elevator shaft to be applied in accordance with the determined safety limit, and generating a control signal to an elevator control portion of the control system of the elevator, the control signal carrying data defining the number of restrictions at least in relation to the movement of the elevator car in the elevator shaft.

The measurement data may e.g. be received from at least one sensor arranged in the elevator shaft.

The safety limit for the elevator car may be determined as a position in the elevator shaft.

Moreover, the number of restrictions in relation to the movement of the elevator car may comprise at least one end point of a travel path of the elevator car. The number of restrictions may further comprise at least one motional parameter, such as a speed of the elevator car, an acceleration of the elevator car, a deceleration of the elevator car.

The method may further comprise: determining a safety limit in the elevator shaft into which a counterweight of the elevator is allowed to travel, the safety limit is determined based on the level of water in the elevator shaft, setting a number of restrictions in relation to a movement of the counterweight in the elevator shaft to be applied in accordance with the determined safety limit.

For example, the safety limit for the counterweight may be determined to reside below the level of water in the elevator shaft.

The safety limit for the counterweight may be determined as a position in the elevator shaft.

The number of restrictions in relation to the movement of the counterweight may comprise at least one end point of a travel path of the counterweight. Still further, the number of restrictions may comprise at least one motional parameter, such as a speed of the counterweight, an acceleration of the counterweight, a deceleration of the counterweight. The at least one motional parameter may be defined to be a speed profile for the counterweight to cause the counterweight to hit the level of water in a controlled manner when the safety limit for the counterweight is defined to reside below the level of water in the elevator shaft.

The method may further comprise at least one of: generating a control signal to the elevator control portion of the control system of the elevator, the control signal carrying data defining the number of restrictions at least in relation to the movement of the counterweight in the elevator shaft; including the data defining the number of restrictions at least in relation to the movement of the counterweight in the elevator shaft to the control signal carrying data defining the number of restrictions at least in relation to the movement of the elevator car in the elevator shaft.

The method may further comprise: modifying a safety circuit monitored by the safety portion of the control system in accordance with the level of water.

For example, the modification may be performed by blocking out a portion of the safety circuit being affected by the level of water from a monitoring by the safety portion of the control system.

According to a second aspect, a control system for controlling an operation of an elevator is provided, a safety portion of the control system of the elevator is configured to: receive measurement data, determine a level of water in an elevator shaft of the elevator based on the measurement data, determine a safety limit above the level of water in the elevator shaft into which at least an elevator car of the elevator is allowed to travel, the safety limit is determined based on the level of water in the elevator shaft, set a number of restrictions in relation to a movement of the elevator car in the elevator shaft to be applied in accordance with the determined safety limit, and generate a control signal to an elevator control portion of the control system of the elevator, the control signal carrying data defining the number of restrictions at least in relation to the movement of the elevator car in the elevator shaft.

The control system may e.g. be configured to receive the measurement data from at least one sensor arranged in the elevator shaft.

The control system may be configured to determine the safety limit for the elevator car as a position in the elevator shaft.

The control system may further be configured to: determine a safety limit in the elevator shaft into which a counterweight of the elevator is allowed to travel, the safety limit is determined based on the level of water in the elevator shaft, set a number of restrictions in relation to a movement of the counterweight in the elevator shaft to be applied in accordance with the determined safety limit. For example, the control system may be configured to determine the safety limit for the counterweight to reside below the level of water in the elevator shaft.

The control system may be configured to determine the safety limit for the counterweight as a position in the elevator shaft.

The number of restrictions in relation to the movement of the counterweight may comprise at least one end point of a travel path of the counterweight. Still further, the number of restrictions may comprise at least one motional parameter, such as a speed of the counterweight, an acceleration of the counterweight, a deceleration of the counterweight. The control system may be configured to define the at least one motional parameter to be a speed profile for the counterweight to cause the counterweight to hit the level of water in a controlled manner when the safety limit for the counterweight is defined to reside below the level of water in the elevator shaft.

The control system may further be configured to perform at least one of: generate a control signal to the elevator control portion of the control system of the elevator, the control signal carrying data defining the number of restrictions at least in relation to the movement of the counter-weight in the elevator shaft; include the data defining the number of restrictions at least in relation to the movement of the counterweight in the elevator shaft to the control signal carrying data defining the number of restrictions at least in relation to the movement of the elevator car in the elevator shaft.

The control system may further be configured to: modify a safety circuit monitored by the safety portion of the control system in accordance with the level of water.

For example, the control system may be configured to perform the modification by blocking out a portion of the safety circuit being affected by the level of water from a monitoring by the safety portion of the control system. According to a third aspect, a computer program is provided, the computer program comprising instructions which, when the program is executed by a control system according to the second aspect as defined above to carry out the method according to the first aspect as defined above.

According to a fourth aspect, a computer-readable medium having stored thereon the computer program according to the third aspect as defined above.

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 an elevator according to an example.

Figure 2 illustrates schematically another elevator according to another example. Figure 3 illustrates schematically a method according to an example.

Figure 4 illustrates schematically an aspect according to an example.

Figure 5 illustrates schematically further aspects of a method according to an example.

Figures 6A and 6B illustrate schematically a control system according to various examples.

Figure 7 illustrates schematically an example of a controller 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 illustrates schematically an example of an elevator 100 into which the invention in accordance with an embodiment of the present invention is implemented to. The elevator 100, i.e. the elevator system, is a counterbalance based elevator system in which an elevator car 110 is connected to a counterbalance 120 with an elevator rope 130 over a traction sheave 140 in a known manner. A rotation of the traction sheave 140 is achieve by a generation of a force for rotating the traction sheave 140 with an electric motor 150 controlled from a drive system 160. The drive system 160, in turn, is controlled by a control system 165 comprising an elevator control portion 170 which is a main controlling entity of the elevator 100. For example, the elevator control portion 170 may be provided with a task to operate the elevator 100 in accordance with elevator calls received from passengers willing to use the elevator service.

In addition to above the control system 165 of the elevator 100, in accordance with the present invention, comprises a safety portion 180 which may be provided with various tasks in relation to safety aspects of the elevator 100. The safety portion 180 may be arranged to receive data from a safety chain e.g. comprising a number of sensors and other devices from which the safety portion 180 may receive data and control e.g. safety switches as well as communicate with the elevator control portion 170. In accordance with the present invention the safety portion 180 may receive measurement data from a sensor chain comprising a number of sensors 190. In other words, the number of sensors 190 may be communicatively connected to the safety chain or the communication with the safety portion 180 may be arranged with one or more communication channels. In accordance with an embodiment, the sensors 190 in the chain of sensors may be mounted in the elevator shaft 195 so that they are configured to provide measurement data from different levels of the elevator shaft 195 in a vertical direction. The sensors in such an embodiment may be sensors 190 which may provide measurement data descriptive that the respective sensor 190 is below the level of water L, i.e. that the water has reached the respective sensor 190. For example, the below most sensor 190 of Figure 1 may generate measurement data differing from the measurement data received from the other sensors 190 based on which a decision on the level of the water L in the elevator shaft 195 may be made at a required accuracy. As a non-limiting example of the sensor type applicable in the above described embodiment may be a pressure sensor. According to another embodiment the chain of sensors may comprise one or more sensors 190 suitable to detect range, or distance, from a predefined object. For example, such a sensor 190 may be mounted on an upper section of the elevator shaft 195 and arranged to measure the level of water downwards. In other words, since applicable sensors 190 in this kind of embodiment are typically transmitting radiation or sonic waves, such as ultrasound, are receiving back a reflection from at least from a monitored object, i.e. from the water surface, data descriptive of the level of water in the elevator shaft 195 may be generated. This kind of embodiment is shown in Figure 2 in which the sensor 190 resides in the upper part of the elevator shaft 195 and is arranged to transmit a measurement signal towards a bottom of the elevator shaft 195 and in case water has accessed to the elevator shaft 195 a reflection to the measurement signal, such as radiation, is received from the surface of the water and the sensor may generate measurement data descriptive of the reflection based on which the level information may be generated in a known manner. Dependent on the size, i.e. the height of the elevator shaft 195, the implementation in accordance with the Figure 2 as described above may require that a plurality of sensors 190 are mounted along the length of the elevator shaft 195 in accordance with an operational range of the used sensors 190. It is worthwhile to mention that the generation of the measurement data descriptive of the level of water, if any, in the elevator shaft 195 is not only limited to the sensor arrangements described in the foregoing description, but also other type of sensors and/or sensor implementations may be applied to. For sake of completeness, it is also worthwhile to mention that the measurement data from the sensor(s) 190 may be delivered to the elevator control portion 170 in addition to the safety portion 180.

The elevator control portion 170 and the safety portion 180 are illustrated in Figure 1 as separate functions, but they may at least in some example embodiments be integrated into the same entity in the control system 165 and the functions are executed therein as is described more accurately in the forthcoming description.

Still further, the elevator control portion 170 may be provided with a number of parameters to be applied when operating the elevator 100. Such parameters may define one or more limits, or restrictions, in relation to the operation of the elevator 100. As an example, the parameter may define at least in part aspects relating to a travel path of the elevator 100, such as defining a position to which the elevator car 110, but possibly also the counterweight are allowed to travel in the elevator shaft 195. In other words, at least one limit of the travel path may be defined with at least one parameter, such as a position in a vertical direction in the shaft. Moreover, in addition to the definition of aspects of the travel path with respect to at least one entity of the elevator 100 one or more parameters may be defined to control the movement itself. Such parameters may define, or limit, a travel speed of the elevator car 110, and thus the counterweight, at a predefined situation, but also aspects in relation to an acceleration / a deceleration may be defined.

Figure 3 illustrates schematically an example of a method according to an embodiment of the invention. The method is described from a standpoint of a safety portion 180 in the non-limiting implementation of the elevator system as shown in Figure 1 .

The safety portion 180 may be configured to receive 310 data originating from the number of sensors 190 belonging to the chain of sensors wherein the data is descriptive of a level of water in an elevator shaft of the elevator 100. The receipt of data may be arranged so that the sensor(s) in the chain of sensors are configured to transmit measurement data at predefined intervals or even continuously to the safety portion 180. The transmission of data may occur directly to the safety portion 180 or indirectly through another entity, such as through the elevator control portion 170. Alternatively or in addition, the safety portion 180 may be configured to request measurement data from the sensor(s) 190 at instants when the data is needed. The request of data may be implemented with a request and response mechanism and the safety portion 180 may perform the request individually to each sensor 190 from which it needs the measurement data or collectively by generating the request to all the sensors 190 at the same time. The previous approach is advantageous in a sense that the amount of data to be transferred may be optimized and, thus, transmission and computing resources may be optimally used. In the request-response approach the safety portion 180 may generate the request either directly to respective sensor(s) 190 or indirectly through another entity, such as the elevator control portion 170. For sake of clarity the term measurement data shall be understood as data descriptive of the level of water so that the safety portion 180 may perform the operation as described in the following. Thus, the measurement data may be raw data from the sensor(s) 190 and/or any processed data therefrom.

On the basis of the data received by the safety portion 180 the safety portion 180 is configured to determine 320 the level of water in the elevator shaft 195 of the elevator 100. The determination 320 may be performed with a desired accuracy in order to generate data descriptive of the level of the water. In other words, it may be based on a detection of sensor(s) 190 being under the water level in the elevator shaft 195 wherein the sensor positions in the shaft may be known. Alternatively or in addition, the data descriptive of the level of the water may be accurately measured e.g. with a radiation based, or a reflection based, measurement arrangement in terms of the accuracy of the measurement system. Depending on the approach the entity performing the detection of the level of water in the shaft 195 may also be configured to perform further analysis based on the data received from the sensor(s) 190, such as determining a speed in which the water increases, or decreases, in the elevator shaft 195 e.g. in terms of time. Without saying it is clear that at least some approaches for determining 320 the level of water, and any derivatives of that, may require setting of one or more reference levels, such as defining a zero level being at the bottom of the elevator shaft 195. For sake of clarity it is worthwhile to mention that the step of determining the level of water 320 also covers an implementation of the invention in which the safety portion 180 receives data directly descriptive of the level of water from another entity, such as from the elevator control portion 170 or even from the sensor(s) 190. In other words, the safety portion 180 only interprets the received data without performing any analysis to it.

In response to the determination 320 of the level of water the safety portion 180 is at least configured to determine 330 a safety limit above the level of water in the elevator shaft 195 into which at least an elevator car 110 of the elevator 100 is allowed to travel. A non-limiting example of the determined safety limit is shown in Figure 1 (reference SL). In other words, the safety portion 180 may be configured to take the information on the level of water and determine a position, or level, in the elevator shaft 195 above the level of water as a safety limit with respect to the level of water. For example, a landing floor may be considered as a candidate to be set as the safety limit because it enables passengers to enter to and exit from the elevator car 110, but it may be any other position in the elevator shaft 195. For sake of clarity it is worthwhile to mention that the safety limit set at a landing floor is not necessarily set to the next landing floor above the level of water, but there may be defined further guard distance e.g. so that the safely limit is set to reside at a landing floor having one or more other landing floors between the level of water and the landing floor set as the safely limit. In other words, the safety portion 180 may be configured to apply a predefined logic, defined by a number of rules, in determining 330 a safety limit at least to the elevator car 110 wherein the respective safety limit is determined 330 based on the data descriptive of the level of water in the elevator shaft 195. As is derivable from above the safety limit is determined 330 and defined as data descriptive in one way or another as a reference position for limiting a travel of the elevator car 110 in a manner as described in the following. The safety limit, SL, may thus be a data value expressed in an appropriate way, such as an exact position in the elevator shaft 195 or as a landing floor.

In response to the determination 330 of the safety limit for the elevator car 110 the safety portion 180 may be configured to set 340 a number of restrictions at least in relation to a movement of the elevator car 110 in the elevator shaft 195 to be applied in accordance with the determined safety limit. This may correspond to that at least one operational parameter of the elevator 100 is set so that it takes into account the defined safety limit. The at least one parameter may a positional parameter corresponding to at least one end point of a travel path of the elevator car 110 in a vertical direction towards the water, i.e. a position in the elevator shaft 195 expressed in a desired accuracy, such as a strict position value or as a landing floor. The other end point, such as the topmost landing floor may be maintained, unless there is also reasons to change that. At least one other operational parameter which may be set 340 to restrict the movement of the elevator car 110 may be at least one motional parameter relating to at least one characteristic of a movement of the elevator car 110. Such motional parameter may e.g. be an allowed speed of the elevator car 110, but also parameters defining an acceleration and/or a deceleration of the elevator car 110 may be set. For example, it may be set that the elevator car 110 is allowed to start deceleration earlier than normally in a situation that the safety limit is set, i.e. in respect to the safety limit defined in the elevator shaft 195. Generally speaking, in step 340 the safety portion 180 may be configured to set the determined safety limit as a position to correspond to an end point of the travel path of the elevator car as applied in a normal situation, i.e. the elevator 100 operates normally and no water has ended up to the elevator shaft 195. Thus, the same rules in relation to the movement of the elevator car 110 may be applied with respect to the safety limit defined due to the water in the elevator shaft 195. However, as said the restriction (s) set due to the access of the water in the elevator shaft 195 may differ from the corresponding one(s) in the normal situation.

In accordance with setting 340 of the one or more restrictions defining operational aspects of the elevator 100 the safety portion 180 generates a control signal to the elevator control portion 170 of the elevator 100 to cause an application of the restriction (s) in the operation of the elevator 100. In other words, the control signal carries data defining the number of restrictions at least in relation to the movement of the elevator car 110 in the elevator shaft 195. Upon the receipt of the control signal the elevator control portion 170 may start applying the one or more operational parameters defined by the data in the control signal.

In the above given description of the method according to an embodiment of the invention the safety limit, and the respective restrictions, are defined primarily with respect to the movement of the elevator car 110. However, the invention also provides a possibility to define another safety limit, and other restriction(s), to other entities in the elevator 100 which may become affected by the water accessed in the elevator shaft 195. An entity being directly affected by the water may be the counterweight 120 because it moves in the elevator shaft 195 together with the elevator car 110 in the known manner. In other words, depending on the travel direction the counterweight 120 may also reach the level of water and, therefore, the present invention may also be configured to address the counterweight 120 in the corresponding manner as the elevator car 110. Thus, according to an embodiment the same safety limit, SL, and the one or more restrictions, as defined for the elevator car 110 may be directly applied with respect to the counterweight 120. However, the present invention allows an implementation of the solution in even more sophisticated way as discussed in the following.

Namely, in accordance with some embodiments of the invention the safety portion 180 may be configured to determine a second safety limit that is applied with respect to the counterweight 120 and wherein the second safety limit differs from the first safety limit determined with respect to the elevator car 110. An example of safety limits differing from each other are schematically illustrated in Figure 4. The first safety limit denoted with SL1 in Figure 4 may correspond to the safety limit defined for the elevator car 110 as is described in the foregoing description. The second safety limit denoted with SL2 in Figure 4 may correspond to a safety limit defined, or determined, for the counterweight 120 and as may be seen that the second safety limit SL2 may be set to allow the elevator 100 to move the counterweight 120 closer to the level of water L than the first safety limit SL1 allows to move the elevator car 110. The approach is considered to emphasize safety of the passengers possibly residing in the elevator car 110, but at least some entities, such as the ones not provided with electricity, are allowed to travel closer to the level of water L, or even allowed to travel below the level of water L. The advantage of having a plurality of safety limits SL1 , SL2 is that it may allow a longer travel path for the moving entities, such as enabling the elevator car 110 reaching higher floors, since the counterweight 120 is allowed to travel vertically lower than the elevator car 110. This kind of approach may be advantageous in emergency situation in which the water has entered the elevator shaft 195, and even rising therein. In principle, the safety limits SL1 , SL2 may be determined so that the safety limit SL1 for the elevator car 110 is set at a lower level than the safety limit SL2 for the counterweight 120, but in most situations that is not meaningful in order to increase the safety of passengers.

Figure 5 illustrates schematically at least some method steps depicting how at least some rules for operating the elevator 100 may be established wherein the restrictions, or rules, are counterweight 120 related. First, in order to establish the safety limit SL2 for the counterweight 120 the safety portion 180 may be configured to, upon the determination 320 of the level of water, apply a predefined logic, defined by rules, in determining 510 the safety limit SL2 for the counterweight 120. The predefined logic applied by the safety portion 180 may be specifically defined for determining 510 the second safety limit SL2 and it may differ from the predefined logic applied for determining 330 the first safety limit SL2 for the elevator car 110. The determinations 330, 510 by applying the respective logics may be conducted simultaneously at least in part or consecutive to each other by the safety portion 180.

For sake of completeness it is worthwhile to mention that the logic, and the applying of the logics, may refer to an implementation in which the safety portion 180 is arranged to execute a computer program which takes the data descriptive of the level of the water as an input and is configured to output one or more safety limits SL, SL1 , SL2 as an output. The computer program is programmed so that it executes predefined rules which generate the safety limits. For example, the computer program may retrieve the safety limits for the elevator car 110 and the counterweight 120 from a data table defining the safety limits with respect to the level of water. As said, each safety limit may define a position in the elevator shaft 195 or a distance e.g. with respect to the level of water, or any similar parameter which may be applied in the further steps of the method.

In response to the determination 510 of the safety limit SL2, i.e. a position in the elevator shaft 195, for the counterweight 120 the safety portion 180 may be configured to set 520 one or more restrictions 340 in relation to a movement of the counterweight 120. This may correspond to that at least one operational parameter of the elevator 100 is set 520 so that it takes into account the safety limit SL2 determined 510 for the counterweight 120. The at least one parameter may at least one positional parameter corresponding to at least be an end point of a travel path of the counterweight 120 in a vertical direction with respect to the level of water. The other end point, such as the end point of the travel of the counterweight in an upper section of the elevator shaft 195, may be maintained unless there is also reasons to change that. As mentioned in the foregoing description the end point for the movement of the counterweight 120 may even be set to reside below the level of water in the vertical direction. At least one other operational parameter which may be set to restrict the movement of the counterweight 120 may be a motional parameter relating to at least one characteristic of a movement of the counterweight 120. Such motional parameter may e.g. be an allowed speed of the counterweight 120, but also parameters defining an acceleration and/or a deceleration of the counterweight 120 may be set. The motional parameters, such as the speed and the acceleration/deceleration, definable for the counterweight 120 may be important especially in an approach in which the counterweight is allowed to travel below the level of the water and in such a case the parameters may be defined to be lower than set in the situation that the counterweight 120 is not allowed to end up below the level of the water. This is because by limiting the speed and/or the acceleration/deceleration it is possible to alleviate the shock experienced by the elevator system, but also by the passengers, when the counterweight 120 hits the water surface when the counterweight 120 travels downwards. Furthermore, the limiting of the speed and/or acceleration/deceleration protects the machinery of the elevator 100 especially when the counterweight 120 is instructed to travel up away from the water from the water. The at least one motional parameter may e.g. be defined with a speed profile defined for a situation that the safety limit SL, SL1 , SL2 for the counterweight 120 is determined to reside below the level of water in the elevator shaft 195. The speed profile may at least be defined so that it allows the counterweight to hit the level of water in a controlled manner to avoiding the above described undesired effects. The speed profile may also define motional parameters, such as speed, to the other direction, i.e. for a situation when the counterweight is lifted up from the water so that any sudden pulldown claw may be avoided when the counterweights 120 exits the water. Such a definition of the motional parameter with the speed profile helps protecting the functional parts and the operation of the elevator as well as preventing scary situations to passengers. In accordance with the some embodiments of the invention the data defining the number of restrictions in relation to the movement of the counterweight 120 may be included in the same control signal as the ones defining the number of restrictions in relation to the movement of the elevator car 110, and the elevator control portion 170 may be arranged to manage all the restrictions in an appropriate way to take them into use in a correct way. This option is referred with a reference 350 in Figure 5. Alternatively, the safety portion 180 may be configured to generate separate control signals to the elevator control portion 170 wherein each control signal carries data descriptive of the number of restrictions for each of the respective entities, i.e. separately for the elevator car 110 and for the counterweight 120. Thus, the control signal generated in step 350 only carries the number of restrictions for the elevator car 110 and another control signal is generated which carries the number of restrictions for the counterweight 120. This is referred with the reference 530 in Figure 5. The steps 350 and 530 are drawn with dashed lines in Figure 5 to indicate that they are alternative to each other. However, nothing prevents to execute both the steps if seen necessary.

In the above given description it is described that the number restrictions are defined and set separately for the elevator car 110 and the counterweight 120. In order to apply the number of restrictions in an appropriate way they may be made dependent on a direction of a travel of the elevator 100, e.g. determined based on the travel direction of the elevator car 110, or the counterweight 120. In other words, if the elevator car 110 travels downwards in the vertical direction, i.e. towards the water, the first safety limit SL1 , and the restrictions based on that, may be applied to and if the elevator car 110 travels upwards in the vertical direction, the second safety limit SL2, and the restrictions based on that, may be applied to, since the counterweight 120 travels towards the water. Hence, the data provided to the elevator control portion 170 from the safety portion 180 defines the dependency of the applied number of restrictions with the travel direction of the elevator. In accordance with at least some embodiments of the invention the safety portion 180 may be configured to perform a safety monitoring of the elevator 100 in response to the setting of the new restrictions for the operation of the elevator 100. This may comprise, but is not limited to, an activation of a machinery brake to stop a movement of the elevator car 110 in response to a detection that the elevator 100, i.e. one or more entities of the elevator 100, does not follow the restrictions set by the safety portion 180 with respect to the operation of the elevator 100 by generating 350 the control signal as described to the elevator control portion 170. The detection may e.g. be based on that either the elevator car 110 or the counterweight 120 travels beyond the respective end point of the travel path and/or a motion related parameter set for the operation, such as the speed and/or the acceleration and/or the deceleration, is not met, such as it is exceeded. Thus, the safety portion 180 may be configured to conduct an emergency stop by generating a control signal to the machinery brake to perform a braking operation either directly or through instructing the elevator control portion 170 to do so.

Moreover, the safety portion 180 may further be configured to, in response to the emergency stop, allow a restart of the elevator 100. The restart may be allowed in response to a detection that the restart is safe to perform. This may e.g. be made dependent on the level of water L, or any other event or situation. For example, prior to allowing the elevator 100 to restart the safety portion 180 may be configured to re-perform the method in accordance with the invention in order to set the elevator 100 to operate in a desired way by re-delivering the one or more restrictions, or newly defined restrictions e.g. due to another level of water than previously, to the elevator control portion 170. In other words, by conducting the restart it is possible to move the elevator car 110, or the counterweight 120, away from a risk level due to the water. Thus, the safety portion 180 may also be configured to perform a monitoring of the travel direction, and limit it, upon the restart in order to confirm that the elevator 100 starts moving the respective entities into a desired direction. In some embodiments the safety portion 180 may be configured to take into account a change in the level of water when determining one or more safety limits SL, SL1 , SL2 and deriving the number of restrictions therefrom. This may be arranged so that upon a determination of a plurality of values descriptive of the level of water the safety portion 180 may be configured to determine ascending/descending speed of the level of water and dynamically re-set the safety limit(s) SL, SL1 , SL2 in accordance with the determined value descriptive of the ascending/descending speed. In this manner it is possible to prepare in advance to the changes in the level of water and, thus, efficiently operate the elevator 100 in a safe manner.

Still further, in some further implementations of the present invention, in addition to features as described above, the safety portion 180 may be configured to monitor an operation of the safety circuit in accordance with the determination of the at least one safety limit SL, SL1 , SL2 and modify the monitoring accordingly. Namely, the operation of the safety circuit may become affected due to the level of the water in the elevator shaft 195. For example, an elevator door may get opened due to water pressure and this causes an opening of the safety switch monitoring the respective floor which leans to activation of the safety circuit preventing the operation of the elevator. Such a situation may not be desired in the described situation and, therefore, the safety portion 180 may be configured to block out at least a portion of the safety circuit from monitoring by the safety portion 180 in order to allow a continuous operation of the elevator 100. The blocking out of the monitoring may refer to an approach that the safety portion 180 is arranged to ignore the opening of the respective safety switches or it is configured to short circuit at least some of the safety switches from the safety circuit, or both.

In the description herein it is discussed that the control system 165 of the elevator 100 may be configured to implement the safety portion 180 and the elevator control portion 170 wherein the safety portion 180 and the elevator control portion 170 may be implemented with respective portions of computer software which are executed by a processing entity to cause the implementation of at least some steps of the method. Figures 6A and 6B illustrate schematically various non-limiting examples of the control system 165 according to various embodiments. Figure 6A illustrates schematically an embodiment in which the safety portion 180 and the elevator control portion 170 are executed in a controller 610 of the control system 165. In other words, one controller 610 configured to execute both the functionality of the safety portion 180 and the functionality of the elevator control portion 170. Thus, the safety portion 180 and the elevator control portion 170 may be interpreted as computer software portions executed by the controller of the elevator 100 wherein the controller may e.g. be an elevator controller. Both portions 170, 180 may thus be arranged to execute their dedicated task for serving the present invention and a control signal between the software portions is arranged to carry the data as described in the foregoing description. The control system 165 may also be implemented so that the safety portion 180 and the elevator control portion 170 are executed by dedicated controllers denoted with 620 and 630 in Figure 6B. The controller denoted with 620 in Figure 6B may e.g. be a safety controller of the safety chain whereas the controller 630 may e.g. be an elevator controller. Hence, the control system 165 may comprise two separate controllers arranged to share data between each other at least by means of the control signal in accordance with the description given herein on the present invention. Both embodiments of Figures 6A and 6B are applicable as such, but the embodiment of Figure 6B is advantageous in a sense that since the operations of the safety portion 180 and the elevator control portion 170 are separated it improves the safety since the safety portion 180 remains operative even if there occurs a malfunction in the elevator control portion 170 side. In other words, even if the elevator controller 630 malfunctions the safety controller 620 continues its operation which is not the case if both functionalities are implemented in the same controller as e.g. shown in Figure 6A.

Figure 7 illustrates schematically an example of a controller suitable for applied in the control system 165 as described. An example of an apparatus configurable to implement the operation of the controller in the control system 165 is schematically illustrated in Figure 7. For sake of clarity, it is worthwhile to mention that the block diagram of Figure 7 depicts some components of an entity that may be employed to implement a functionality of the controller. The apparatus of Figure 7 comprises a processor 710 and a memory 720. The memory 720 may store data, such as pieces of data as described, but also computer program code 725 consisting of one or more software portions, such as the safety portion 180 and/or the elevator control portion 170, causing the operation in the described manner. The apparatus may further comprise a communication interface 730, such as a wireless communication interface or a communication interface for wired communication, or both to communicate with other entities as described. The communication interface 730 may thus comprise one or more modems, antennas, and any other hardware and software for enabling an execution of the communication e.g. under control of the processor 710. Furthermore, I/O (input/output) components may be arranged, together with the processor 710 and a portion of the computer program code 725, to provide a user interface for receiving input from a user, such as from a technician, and/or providing output to the user of the apparatus when necessary. In particular, the I/O components may include user input means, such as one or more keys or buttons, a keyboard, a touchscreen, or a touchpad, etc. The I/O components may include output means, such as a loudspeaker, a display, or a touchscreen. The components of the apparatus may be communicatively connected to each other via data bus that enables transfer of data and control information between the components.

The memory 720 and at least a portion of the computer program code 725 stored therein may further be arranged, with the processor 710, to cause the apparatus to perform at least a portion of a method as is described herein. The processor 710 may be configured to read from and write to the memory 720. Although the processor 710 is depicted as a respective single component, it may be implemented as respective one or more separate processing components. Similarly, although the memory 720 is depicted as a respective single component, it may be implemented as respective one or more separate com-ponents, some, or all of which may be integrated ! removable and ! or may provide permanent I semi-permanent I dynamic I cached storage.

The computer program code 725 may comprise computer-executable instructions that implement functions that correspond to steps implemented in the method when loaded into the processor 710 of the respective controller. As an example, the computer program code 725 may include a computer program consisting of one or more sequences of one or more instructions. The processor 710 is able to load and execute the computer program by reading the one or more sequences of one or more instructions included therein from the memory 720. The one or more sequences of one or more instructions may be configured to, when executed by the processor 710, cause the apparatus, such as a computer, to perform a method as described. Hence, the apparatus may comprise at least one processor 710 and at least one memory 720 including the computer program code 725 for one or more programs, the at least one memory 720 and the computer program code 725 configured to, with the at least one processor 710, cause the apparatus to be involved in performing the method.

The computer program code 725, or at least some portion of it, may be provided e.g. a computer program product comprising at least one computer- readable non-transitory medium having the computer program code 725 stored thereon, which computer program code 725, when executed by the processor 710 causes the apparatus to perform the method. The computer- readable non-transitory medium may comprise a memory device or a record medium, such as a CD-ROM, a DVD, a Blu-ray disc, or another article of manufacture that tangibly embodies the computer program. As another example, the computer program may be provided as a signal configured to reliably transfer the computer program.

Still further, the computer program code 725 may comprise a proprietary application, such as computer program code for causing an execution of the method in the manner as described in the description herein. Any of the programmed functions mentioned may also be performed in firmware or hardware adapted to or programmed to perform the necessary tasks.

For sake of completeness it is worthwhile to mention that the entity performing the method in the role of the controller may also be implemented with a plurality of apparatuses, such as the one schematically illustrated in Figure 7, as a distributed computing environment corresponding to a controller, or the control system 165. For example, one of the apparatuses may be communicatively connected with the other apparatuses, and e.g. share the data of the method, to cause another apparatus to perform at least one other portion of the method.

As a result, the method performed in the distributed computing environment generates the control signal indicative of the assignment of the responsibility as described. The functionalities of the controller as described may also be integrated to an entity also configured to perform other operations. 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.

Claims

WHAT IS CLAIMED IS:

1. A method for controlling an operation of an elevator (100), the method, performed by a safety portion (180) of a control system (165) of the elevator (100), comprises: receiving (310) measurement data, determining (320) a level of water in an elevator shaft (195) of the elevator (100) based on the measurement data, determining (330) a safety limit (SL, SL1 , SL2) above the level of water in the elevator shaft (195) into which at least an elevator car (110) of the elevator (100) is allowed to travel, the safety limit (SL, SL1 , SL2) is determined based on the level of water in the elevator shaft (195), setting (340) a number of restrictions in relation to a movement of the elevator car (110) in the elevator shaft (195) to be applied in accordance with the determined safety limit (SL, SL1 , SL2), and generating (350) a control signal to an elevator control portion (170) of the control system (165) of the elevator (100), the control signal carrying data defining the number of restrictions at least in relation to the movement of the elevator car (110) in the elevator shaft (195).

2. The method according to claim 1 , wherein the measurement data is received from at least one sensor (190) arranged in the elevator shaft (195).

3. The method according to any of the preceding claims, wherein the safety limit (SL, SL1 , SL2) for the elevator car (110) is determined (330) as a position in the elevator shaft (195).

4. The method according to any of the preceding claims, wherein the number of restrictions in relation to the movement of the elevator car (110) comprises at least one end point of a travel path of the elevator car (110).

5. The method according to claim 4, wherein the number of restrictions further comprises at least one motional parameter, such as a speed of the elevator car (110), an acceleration of the elevator car (110), a deceleration of the elevator car (110).

6. The method according to any of the preceding claims, the method further comprising: determining (510) a safety limit (SL, SL1 , SL2) in the elevator shaft (195) into which a counterweight (120) of the elevator (100) is allowed to travel, the safety limit (SL, SL1 , SL2) is determined based on the level of water in the elevator shaft (195), setting (520) a number of restrictions in relation to a movement of the counterweight (120) in the elevator shaft (195) to be applied in accordance with the determined safety limit (SL, SL1 , SL2).

7. The method according to claim 6, wherein the safety limit (SL, SL1 , SL2) for the counterweight (120) is determined to reside below the level of water in the elevator shaft (195).

8. The method according to claim 6 or claim 7, wherein the safety limit (SL, SL1 , SL2) for the counterweight (120) is determined (330) as a position in the elevator shaft (195).

9. The method according to any or the preceding claims 6 to 8, wherein the number of restrictions in relation to the movement of the counterweight (120) comprises at least one end point of a travel path of the counterweight (120).

10. The method according to claim 6 to 9, wherein the number of restrictions comprises at least one motional parameter, such as a speed of the counterweight (120), an acceleration of the counterweight (120), a deceleration of the counterweight (120).

11. The method according to claim 10, wherein the at least one motional parameter is defined to be a speed profile for the counterweight (120) to cause the counterweight (120) to hit the level of water in a controlled manner when the safety limit (SL, SL1 , SL2) for the counterweight (120) is defined in accordance with claim 7.

12. The method according to any of claims 6 to 11 , the method further comprises at least one of: generating (530) a control signal to the elevator control portion (170) of the control system (165) of the elevator (100), the control signal carrying data defining the number of restrictions at least in relation to the movement of the counterweight (120) in the elevator shaft (195); including the data defining the number of restrictions at least in relation to the movement of the counterweight (120) in the elevator shaft (195) to the control signal carrying data defining the number of restrictions at least in relation to the movement of the elevator car (110) in the elevator shaft (195).

13. The method according to any or the preceding claims, the method further comprises: modifying a safety circuit monitored by the safety portion (180) of the control system (165) in accordance with the level of water.

14. The method according to claim 13, wherein the modification is performed by blocking out a portion of the safety circuit being affected by the level of water from a monitoring by the safety portion (180) of the control system (165).

15. A control system (165) for controlling an operation of an elevator (100), a safety portion (180) of the control system (165) of the elevator (100) is configured to: receive (310) measurement data, determine (320) a level of water in an elevator shaft (195) of the elevator (100) based on the measurement data, determine (330) a safety limit (SL, SL1 , SL2) above the level of water in the elevator shaft (195) into which at least an elevator car (110) of the elevator (100) is allowed to travel, the safety limit (SL, SL1 , SL2) is determined based on the level of water in the elevator shaft (195), set (340) a number of restrictions in relation to a movement of the elevator car (110) in the elevator shaft (195) to be applied in accordance with the determined safety limit (SL, SL1 , SL2), and generate (350) a control signal to an elevator control portion (170) of the control system (165) of the elevator (100), the control signal carrying data defining the number of restrictions at least in relation to the movement of the elevator car (110) in the elevator shaft (195).

16. The control system (165) according to claim 15, wherein the control system (165) is configured to receive the measurement data from at least one sensor (190) arranged in the elevator shaft (195).

17. The control system (165) according to claim 15 or claim 16, wherein the control system (165) is configured to determine (330) the safety limit (SL, SL1 , SL2) for the elevator car (110) as a position in the elevator shaft (195).

18. The control system (165) according to any of the preceding claims 15 to 17, wherein the number of restrictions in relation to the movement of the elevator car (110) comprises at least one end point of a travel path of the elevator car (110).

19. The control system (165) according to claim 18, wherein the number of restrictions further comprises at least one motional parameter, such as a speed of the elevator car (110), an acceleration of the elevator car (110), a deceleration of the elevator car (110).

20. The control system (165) according to any of the preceding claims 15 to 19, the control system (165) is further configured to: determine (510) a safety limit (SL, SL1 , SL2) in the elevator shaft (195) into which a counterweight (120) of the elevator (100) is allowed to travel, the safety limit (SL, SL1 , SL2) is determined based on the level of water in the elevator shaft (195), set (520) a number of restrictions in relation to a movement of the counterweight (120) in the elevator shaft (195) to be applied in accordance with the determined safety limit (SL, SL1 , SL2).

21. The control system (165) according to claim 20, wherein the control system (165) is configured to determine the safety limit (SL, SL1 , SL2) for the counterweight (120) to reside below the level of water in the elevator shaft (195).

22. The control system (165) according to claim 20 or claim 21 , wherein the control system (165) is configured to determine (330) the safety limit (SL, SL1 , SL2) for the counterweight (120) as a position in the elevator shaft (195).

23. The control system (165) according to any or the preceding claims 20 to 22, wherein the number of restrictions in relation to the movement of the counterweight (120) comprises at least one end point of a travel path of the counterweight (120).

24. The control system (165) according to claim 20 to 23, wherein the number of restrictions comprises at least one motional parameter, such as a speed of the counterweight (120), an acceleration of the counterweight (120), a deceleration of the counterweight (120).

25. The control system (165) according to claim 24, wherein the control system (165) is configured to define the at least one motional parameter to be a speed profile for the counterweight (120) to cause the counterweight (120) to hit the level of water in a controlled manner when the safety limit (SL, SL1 , SL2) for the counterweight (120) is defined in accordance with claim 21 .

26. The control system (165) according to any of claims 20 to 24, the control system (165) is further configured to perform at least one of: generate (530) a control signal to the elevator control portion (170) of the control system (165) of the elevator (100), the control signal carrying data defining the number of restrictions at least in relation to the movement of the counterweight (120) in the elevator shaft (195); include the data defining the number of restrictions at least in relation to the movement of the counterweight (120) in the elevator shaft (195) to the control signal carrying data defining the number of restrictions at least in relation to the movement of the elevator car (110) in the elevator shaft (195).

27. The control system (165) according to any or the preceding claims 15 to 26, the control system (165) is further configured to: modify a safety circuit monitored by the safety portion (180) of the control system (165) in accordance with the level of water.

28. The control system (165) according to claim 27, wherein the control system (165) is configured to perform the modification by blocking out a portion of the safety circuit being affected by the level of water from a monitoring by the safety portion (180) of the control system (165).

29. A computer program comprising instructions which when the program is executed by a control system (165) according to claim 15 to carry out the method according to any of claims 1 to 14.

30. A computer-readable medium having stored thereon the computer program according to claim 29.