TECHNICAL FIELD

The invention concerns in general the technical field of elevators. Especially the invention concerns cleanness of elevator elements.

BACKGROUND

Typically, elevator systems comprise a plurality of elevator element being touchable by users, e.g. passages, and/or being in physical contact with the users, such as elevator call devices, elevator cars and especially the interior parts of the elevator car, etc. For example, in order to make an elevator call, ei ther a landing call, a car call, or a destination call, the user typically needs to physically contact, e.g. by a hand, the elevator call device. The physical con tact to the elevator elements may spread viruses and bacteria, for example when several people make the elevator calls via the same elevator call device or for some other reason physically contacts with one or more elevator ele ments. Moreover, the viruses and bacteria may be spread when a user having symptoms is coughing, sneezing, and/or blowing their nose in an elevator lob by or inside the elevator car. Typically, the elevator elements are cleaned at regular intervals, e.g. once a day. However, in order to reduce the spreading of the viruses and bacteria efficiently, the elevator elements need to be cleaned often enough.

Thus, there is need to develop further solutions in order to improve the clean ing of the elevator elements.

SUMMARY

The following presents a simplified summary in order to provide basic under standing 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 em bodiments of the invention. An objective of the invention is to present a method, an elevator control unit, and an elevator system for generating a cleaning request to clean at least one elevator element of an elevator system. Another objective of the invention is that the method, the elevator control unit, and the elevator system for generat ing a cleaning request to clean at least one elevator element of an elevator system improve effectiveness of cleaning of the elevator elements.

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

According to a first aspect, a method for generating a cleaning request to clean at least one elevator element of an elevator system is provided, wherein the method comprises: obtaining information representing usage rate of the eleva tor system, defining based on the obtained information a cleaning need of at least one elevator element by detecting that the usage rate meets a predefined threshold, and generating a cleaning request to a monitoring unit to clean the at least one elevator element of the elevator system, in response to the defini tion of the cleaning need of the at least one elevator element.

The obtained information representing the usage rate may comprise one or more user events associated with at least one elevator element of the elevator system.

The usage rate may be a total usage rate of the elevator system, wherein the defined cleaning need may be an elevator system level cleaning need defined by detecting that the total usage rate meets a predefined elevator level thresh old.

Alternatively, the usage rate may comprise an elevator element specific usage rate of at least one elevator element of the elevator system, wherein the de fined cleaning need may be an elevator element specific cleaning need de fined by detecting that the usage rate of at least one elevator element of the elevator system meets a predefined element specific threshold.

The elevator element may be at least one component of an elevator user inter face device and/or the user elevator user interface device itself, wherein the user event associated with said elevator element may be a touch by the user or an elevator call generated via said elevator element. Alternatively, the elevator element may be at least one component of an eleva tor car and/or the elevator car itself, wherein the user event associated with said elevator element may be an elevator call served by said elevator car or a number of passengers conveyed by said elevator car.

The method may further comprise: obtaining user health information from at least one sensor device and/or a database, and/or information representing at least one elevator call to at least one specific destination floor and/or departure floor; and weighting the usage rate based on the obtained user health infor mation and/or the obtained information representing the at least one elevator call to at least one specific destination floor and/or departure floor.

Alternatively or in addition, the method may further comprise generating a first control signal to the at least one elevator element to which the cleaning need is defined, wherein the first control signal may comprise instruction to disable the use of the at least one elevator element to which the cleaning need is defined and/or to generate an out of operation indication.

The method may further comprise: receiving a cleaning accomplished infor mation from the monitoring unit, and generating a second control signal to the at least one elevator element to which the cleaning need is defined, in re sponse to receiving the cleaning accomplished information, wherein the sec ond control signal may comprise instruction to re-enable the use of the at least one elevator element to which the cleaning need is defined.

According to a second aspect, an elevator control unit for generating a clean ing request of at least one elevator element of an elevator system is provided, wherein the elevator control unit comprises: at least one processor, and at least one memory storing at least one portion of computer program code, wherein the at least one processor being configured to cause the elevator con trol unit at least to perform: obtain information representing usage rate of the elevator system, define based on the obtained information a cleaning need of at least one elevator element by detecting that the usage rate meets a prede fined threshold, and generate a cleaning request to a monitoring unit to clean the at least one elevator element, in response to detecting the cleaning need of the at least one elevator element. The obtained information representing the usage rate may comprise one or more user events associated with at least one elevator element of the elevator system.

The usage rate may be a total usage rate of the elevator system, wherein the defined cleaning need may be an elevator system level cleaning need defined by detecting that the total usage rate meets a predefined elevator level thresh old.

Alternatively, the usage rate may comprise an elevator element specific usage rate of at least one elevator element of the elevator system, wherein the de fined cleaning need may be an elevator element specific cleaning need de fined by detecting that the usage rate of at least one elevator element of the elevator system meets a predefined element specific threshold.

The elevator element may be at least one component of an elevator user inter face device and/or the user elevator user interface device itself, wherein the user event associated with said elevator element may be a touch by the user or an elevator call generated via said elevator element.

Alternatively, the elevator element may be at least one component of an eleva tor car and/or the elevator car itself, wherein the user event associated with said elevator element may be an elevator call served by said elevator car or a number of passengers conveyed by said elevator car.

The elevator control unit may further be configured to: obtain user health in formation from at least one sensor device and/or a database, and/or infor mation representing at least one elevator call to at least one specific destina tion floor and/or departure floor; and weight the obtained usage rate based on the obtained user health information and/or the obtained information represent ing the at least one elevator call to at least one specific destination floor and/or departure floor.

Alternatively or in addition, the elevator control unit may further be configured to generate a first control signal to the at least one elevator element to which the cleaning need is defined, wherein the first control signal may comprise in struction to disable the use of the at least one elevator element to which the cleaning need is defined and/or to generate an out of operation indication. The elevator control unit may further be configured to: receive a cleaning ac complished information from the monitoring unit, and generate a second con trol signal to the at least one elevator element to which the cleaning need is defined in response to receiving the cleaning accomplished information, wherein the second control signal may comprise instruction to re-enable the use of the at least one elevator element to which the cleaning need is defined.

According to a third aspect, an elevator system for generating a cleaning re quest of at least one elevator element of the elevator system is provided, the elevator system comprises: a plurality of elevator elements, and an elevator control unit as described 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 un less 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 example of an elevator system according to the invention.

Figure 2 illustrates schematically an example of a method according to the in vention.

Figure 3 illustrates schematically another example of an elevator system ac cording to the invention. Figure 4 schematically illustrates an example of components of an elevator control unit according to the invention.

DESCRIPTION OF THE EXEMPLIFYING EMBODIMENTS

Figure 1 illustrates an example of an elevator system 100 for generating a cleaning request to clean at least one elevator element 108a-108n, 110a-110n, 106a-106n of the elevator system 100 according to the invention. The elevator system 100 comprises an elevator control unit 102, at least one elevator shaft 104a-104n along which at least one elevator car 106a-106n is arranged to travel between a plurality of floors, i.e. landings, 112a-112n, and a plurality of elevator user interface devices 108a-108n, 110a-110n for generating elevator calls, e.g. landing calls, car calls, and/or destination calls. The plurality of ele vator interface devices 108a-108n, 110a-110n may comprise a car call device, e.g. car operation panel (COP), 108a-108n arranged to each at least one ele vator car 106a-106n for generating car calls to drive the at least one elevator car 106a-106n to at least one destination floor, and/or at least one landing call device 110a-110n arranged outside the elevator car at each floor 112a-112n, e.g. within an elevator lobby area or an elevator landing area. The at least one landing call device 110a-110n may comprise e.g. at least one landing call pan el for generating landing calls to drive the elevator to said floor 112a-112, where said landing call panel resides, and/or at least one destination operation panel (DOP) for generating destination calls to drive the elevator car to said floor 112a-112, where the destination operation panel resides and then to at least one destination floor.

The elevator system 100 comprises a plurality of elevator elements 108a-108n, 110a-110n, 106a-106n that are in interaction with users, e.g. passengers, of the elevator system 100 via a direct physical contact, e.g. via a touch, and/or or via an indirect contact, e.g. via human secretion spread by coughing, sneez ing, nose blowing, etc. Some examples of these elevator elements 108a-108n, 110a-110n, 106a-106n may be the plurality of user interface devices 108a- 108n, 110a-110n itself; at least one individual part, i.e. component, of each of the plurality of user interface devices 108a-108n, 110a-110n, e.g. one or more buttons, touch screens, displays, etc.; the at least one elevator car itself 106a- 106n; and/or at least one part, i.e. component, of the least one elevator car 106a-106n, e.g. one or more handrails; elevator doors, e.g. landing door(s) or car door(s); floor; ceiling; walls; one or more mirrors; any other interior part of the at least one elevator car 106a-106n; and/or any other interior surface of the at least one elevator car 106a-106n.

According to an example, in order to generate elevator calls, the users need to physically contact, e.g. by a hand, at least one elevator interface device 108a- 108n, 110a-110n, e.g. a button of the at least one elevator interface device 108a-108n, 110a-110n. According to another example, the users may physi cally contact, e.g. touch, at least one part of the at least one elevator car 106a- 106n, e.g. the handrail. According to yet another example, the users may spread human secretion by coughing, sneezing, blowing nose, etc. to at least one of the plurality of elevator user interface devices 108a-108n, 110a-110n, to at least one button of at least one elevator user interface devices 108a-108n, 110a-110n, and/or to at least one interior surface of the at least one elevator car 106a-106n. The physical contact to the elevator elements 108a-108n, 110a-110n, 106a-106n may spread viruses and bacteria, for example when several users are in physical contact with the elevator elements 108a-108n, 110a-110n, 106a-106n.

The elevator control unit 102 is configured to control one or more entities of the elevator system 100 including the plurality of elevator user interface devices 108a-108n, 110a-110n and the at least one elevator car 106a-106n. The ele vator entities may further comprise, but are not limited to, drive circuit and de vices, safety circuit and devices, sensors, elevator door circuits and devices, etc. The implementation of the elevator control unit 102 may be done as a stand-alone control entity or as a distributed control environment between a plurality of stand-alone control entities providing distributed control resource. The elevator control unit may be communicatively coupled to the one or more entities of the elevator system 100. The communication between the elevator control unit 102 and one or more entities of the elevator system 100 may be based on one or more known communication technologies, either wired or wireless.

The elevator control unit 102 may further be communicatively coupled to a monitoring unit 114. The communication between the elevator control unit 102 and the monitoring unit 114 may be based on one or more known communica tion technologies, either wired or wireless. The monitoring unit 114 may be for example, but is not limited to, a building management system (BMS), a service center, or any other monitoring system. The monitoring unit 114 may be exter- nal unit or an internal unit of the elevator system 100. The elevator control unit 102 may be directly coupled to the monitoring unit 114 or via one or more cloud services or other data management systems of different parties, e.g. building manager, elevator maintainer, cleaning service provider, etc.

Next an example of the method according to the invention is described by re ferring to Figure 2. Figure 2 schematically illustrates the invention as a flow chart.

At a step 202, the elevator control unit 102 obtains information, e.g. usage in formation, representing usage rate of the elevator system 100. The information representing the usage rate of the elevator system 100 may be obtained at el evator system level. In other words, the usage rate may be a total usage rate of the elevator system 100, i.e. combined usage rate of the plurality of elevator elements 108a-108n, 110a-110n, 106a-106n of the elevator system 100. This enables monitoring and observation of the total usage rate of the whole eleva tor system 100. Alternatively, the information representing the usage rate of the elevator system 100 may be obtained at elevator element level. In other words, the usage rate may comprise elevator element specific usage rate of at least one elevator element 108a-108n, 110a-110n, 106a-106n of the elevator system 100. This enables monitoring and observation of the usage rates of el evator element 108a-108n, 110a-110n, 106a-106n separately or usage rates of a group of elevator elements 108a-108n, 110a-110n, 106a-106n, i.e. two or more elevator elements 108a-108n, 110a-110n, 106a-106n.

The obtained information representing the usage rate may comprise at least one user event associated with at least one elevator element 108a-108n, 110a-110n, 106a-106n of the elevator system 100. In other words, at least one user event associated with at least one elevator element 108a-108n, 110a- 11 On, 106a-106n may be information representing the usage rate of the eleva tor system 100.

In case of the elevator element 108a-108n, 110a-110n, 106a-106n is at least one component of an elevator user interface device 108a-108n, 110a-110n and/or the user elevator user interface device 108a-108n, 110a-110n itself, the user event associated with said elevator element 108a-108n, 110a-110n, 106a-106n may be e.g. a touch by the user to said elevator element 108a- 108n, 110a-110n, 106a-106n or an elevator call generated via said elevator element 108a-108n, 110a-110n, 106a-106n. In other words, each touch of the users to the at least one component of the elevator user interface device 108a- 108n, 110a-110n and/or the user elevator user interface device 108a-108n, 110a-110n itself may be defined, i.e. counted, as one user event associated with, i.e. directed to, said at least one component of the elevator user interface device 108a-108n, 110a-110n and/or the user elevator user interface device 108a-108n, 110a-110n itself. Alternatively, each elevator call generated via said at least one component of the elevator user interface device 108a-108n, 110a-110n and/or to the user elevator user interface device 108a-108n, 110a- 110n itself may be defined, i.e. counted, as one user event associated with, i.e. directed to, said at least one component of the elevator user interface device 108a-108n, 110a-110n and/or the user elevator user interface device 108a- 108n, 110a-110n itself.

In case of the elevator element 108a-108n, 110a-110n, 106a-106n is at least one component of an elevator car 106a-106n and/or the elevator car 106a- 106n itself, the user event associated with said elevator element 108a-108n, 110a-110n, 106a-106n may be e.g. an elevator call served by said elevator car 106a-106n or a number of passengers conveyed by said elevator car 106a- 106n. In other words, elevator call served by said elevator car 106a-106n may be defined, i.e. counted, as one user event associated with the at least one component of the elevator car 106a-106n and/or the elevator car 106a-106n it self. Alternatively, a predefined number of passengers conveyed by said eleva tor car 106a-106n may be defined, i.e. counted, as one user event associated with the at least one component of the elevator car 106a-106n and/or the ele vator car 106a-106n itself.

The information representing the usage rate of the elevator system 100 may be obtained from at least one internal detection device of the elevator control system 100 and/or from an external detection system. The at least one internal detection device of the elevator system 100 may e.g. be a weighting device ar ranged to the at least one elevator car 106a-106n, e.g. to the floor thereof, a curtain of light arranged to the at least one elevator car 106a-106n and/or any other counting device, e.g. a people counter, configured to define the number of passengers conveyed by the at least one elevator car 106a-106n. Alterna tively or in addition, the at least one internal detection device of the elevator system 100 may e.g. be an internal counter of the elevator control unit 102 configured to count the elevator calls generated via at least part of at least one elevator user interface device 108a-108n, 110a-110n or the at least one user interface device 108a-108n, 110a-110n and/or served by the at least one ele vator car 106a-106n. The external detection system may be a motion detec tion-based system, an indoor position detection system, and/or optical imag ing, e.g. camera, based system configured to obtain data based on which the number of passengers conveyed by the at least one elevator car 106a-106n and/or the elevator calls generated via at least one user interface device may be estimated. For example, based on the obtained data one or more active ar eas of the elevator lobby area, the landing area, and/or inside the at least one elevator car 106a-106n may be identified and the active areas residing in a vi cinity, e.g. within an area in front of, at least one user interface device 108a- 108n, 110a-110n may be used to estimate a number of the elevator calls gen erated via the at least one user interface device 108a-108n, 110a-110n.

At a step 206, the elevator control unit 102 defines based on the obtained in formation a cleaning need by detecting at a step 204 that the usage rate meets a predefined threshold, i.e. a predefined limit value. The predefined threshold may be constant. Alternatively, the predefined threshold may be adjustable ac cording to a prevailing situation. For example, during critical times, e.g. epi demics pandemics and/or similar times, the predefined threshold may be lower than during other non-critical times. The defined cleaning need may concern at least one elevator element 108a-108n, 110a-110n, 106a-106n of the elevator system 100 or the whole elevator system 100 depending on whether the in formation representing the usage rate of the elevator system 100 is obtained at the elevator system level or at the elevator element level. In other words, de pending on whether information representing the usage rate of the elevator system 100 is obtained at the elevator system level or at the elevator element level, the defined cleaning need may be elevator element specific or the de fined cleaning need may be elevator system level. The elevator specific clean ing need may be defined by detecting that the usage rate of at least one eleva tor element 108a-108n, 110a-110n, 106a-106n of the elevator system 100 meets a predefined element specific threshold. The elevator system level cleaning need may be defined by detecting that the usage rate of the whole el evator system 100 meets a predefined elevator level threshold.

At a step 208, the elevator control unit 102 generates a cleaning request to clean at least one elevator element 108a-108n, 110a-110n, 106a-106n of the elevator system 100 to the monitoring unit 114, in response to the definition of the cleaning need. This enables that cleaning intervals of the at least one ele vator element 108a-108n, 110a-110n, 106a-106n of the elevator system or the whole elevator system 100 may be defined based on the usage rate of the ele vator system 100 and/or usage rate of at least one element of the elevator sys tem 100, which in turn, may increase the effectiveness of the cleaning of the at least one elevator element 108a-108n, 110a-110n, 106a-106n of the elevator system 100. Moreover, this enables on-demand cleaning of contaminated at least one elevator element 108a-108n, 110a-110n, 106a-106n of the elevator system 100. The cleaning request may comprise type information of the at least one elevator element 108a-108n, 110a-110n, 106a-106n to be cleaned, location information of the at least one elevator element 108a-108n, 110a- 11 On, 106a-106n to be cleaned, and/or a reason for the cleaning request. In response to receiving the cleaning request the monitoring unit 114 may gener ate to a cleaning service provider an instruction for cleaning the at least one elevator element 108a-108n, 110a-110n, 106a-106n to which the cleaning need in defined. The cleaning may for example comprise, but is not limited to, using one of: a portable disinfecting air-cleaner or ozonator, ultraviolet (UV) light, blue light, photocatalytic oxidation device, aerosols, changing disposable covers, etc.

According to an exemplifying embodiment of the invention, the method may further comprise obtaining, by the elevator control unit 102, user health infor mation and weighting, by the elevator control unit 102, the usage rate based on the obtained user health information. The user health information may be received from at least one sensor device. The at least one sensor device may be an audio sensing device, e.g. a microphone, configured to sense audio data indicative of at least one user having symptoms of a disease, e.g. coughing, sneezing, blowing nose, etc. Alternatively or in addition, the at least one sen sor device may be a thermal imaging device, e.g. an infrared camera, config ured to sense temperature data indicative of at least one user having in creased body temperature. The at least one sensor device may be arranged to an elevator lobby area, a landing area, inside at least one elevator car 106a- 106n, and/or to at least one elevator user interface device 108a-108n, 110a- 11 On. Alternatively or in addition, the user health information may be received from a database to which health information of users may be gathered from dif ferent sources. Some examples of the different sources may comprise, but are not limited to, government data bases, health organizations, user’s own health profile in a mobile phone or a cloud service, and/or dedicated private or gov ernment services for disease spreading monitoring. Alternatively or in addition, the health information of the user may be obtained from a sensor device, e.g. QR code reader, by receiving user input via a QR code, e.g. displayed on a mobile terminal, such as a mobile phone, wherein the QR code comprises the health information of the user. The weighting may comprise scaling up, e.g. in crease, the usage rate in response to obtaining the user health information in dicative of at least one user having symptoms of a disease. This may further increase the effectiveness of the cleaning of the at least one elevator element 108a-108n, 110a-110n, 106a-106n of the elevator system 100. The weighting may be done for the system level usage rate and/or the elevator element spe cific usage rate of at least one elevator element 108a-108n, 110a-110n, 106a- 106n.

According to an exemplifying embodiment of the invention, the method may al ternatively or in addition comprise obtaining, by the elevator control unit 102, information representing at least one elevator call to at least one specific des tination floor and/or departure floor associated with at least one elevator ele ment 108a-108n, 110a-110n, 106a-106n of the elevator system 100 and weighting, by the elevator control unit 102, the usage rate based on the ob tained information representing at least one elevator call to at least one specif ic destination floor and/or departure floor associated with at least one elevator element 108a-108n, 110a-110n, 106a-106n of the elevator system 100. The information representing at least one elevator call to at least one specific des tination floor and/or departure floor associated with at least one elevator ele ment 108a-108n, 110a-110n, 106a-106n of the elevator system 100 may com prise generated elevator calls and/or served elevator calls to floors where lo cate health care services, e.g. a hospital, a health clinic, a health center, etc. The users visiting the health care services may have a higher probability to have symptoms of a disease, thus the elevator elements 108a-108n, 110a- 110n, 106a-106n associated with users visiting these specific destination floors and/or specific departure floors may require more frequent cleaning. The weighting may comprise scaling up, i.e. increase, the usage rate in response to obtaining the information representing at least one elevator call to at least one specific destination floor and/or departure floor. The weighting may be done for the system level usage rate and/or the elevator element specific us age rate of at least one elevator element 108a-108n, 110a-110n, 106a-106n. The information representing at least one elevator call to at least one specific destination floor and/or departure floor associated with at least one elevator element 108a-108n, 110a-110n, 106a-106n of the elevator system 100 may be obtained from at least one internal detection device of the elevator control sys tem 100, e.g. an internal counter of the elevator control unit 102, configured to count the elevator calls generated to the at least one specific destination floor and/or departure floor.

According to an exemplifying embodiment of the invention, the method may al ternatively or in addition comprise generating a first control signal to the at least one elevator element 108a-108n, 110a-110n, 106a-106n to which the cleaning need is defined. The first control signal may comprise instruction to disable the use of the at least one elevator element 108a-108n, 110a-110n, 106a-106n to which the cleaning need is defined and/or to generate an out of operation, i.e. out of use, indication. This may reduce the spread viruses and bacteria because of instructing the users not to use the contaminated at least one elevator element 108a-108n, 110a-110n, 106a-106n before cleaning of the at least one elevator element 108a-108n, 110a-110n, 106a-106n. This is il lustrated in Figure 2 with the optional step 210. For example, if the elevator el ement 108a-108n, 110a-110n, 106a-106n to which the cleaning need is de fined is at least one part of an elevator user interface device 108a-108n, 110a- 11 On, e.g. one button of the elevator user interface device 108a-108n, 110a- 11 On, the use of said button may be disabled and/or a visual indication e.g. a red light around said button, may be generated to indicate that said button is out of operation. According to another example, if the elevator element 108a- 108n, 110a-110n, 106a-106n to which the cleaning need is defined is an ele vator user interface device 108a-108n, 110a-110n itself, the use of said eleva tor user interface device may be disabled, e.g. the device is turned off or in a sleep or idle mode, and/or a visual and/or audio indication may be generated to indicate that said elevator user interface device 108a-108n, 110a-110n is out of operation, e.g. a text-based and/or symbol-based visual indication may be displayed on a display or screen of said elevator user interface device 108a-108n, 110a-110n. If the disabled elevator element 108a-108n, 110a- 11 On, 106a-106n is at least one elevator user interface device 108a-108n, 110a-110n itself, the indication may also comprise guidance to at least one other elevator user interface device 108a-108n, 110a-110n, which is in opera tion, i.e. not disabled. Figure 3 illustrates schematically an example, wherein the cleaning need is defined to the elevator user interface device 110a. The elevator user interface device 110a is disabled and a visual indication is dis played on a screen of the elevator user interface device 110a, wherein the vis ual indication comprises out of operation indication, i.e. a cross symbol, and guidance to other elevator user interface devices 110b and 110c, which are in operation, i.e. text “USE” and the arrow symbol pointing to elevator user inter face devices 110b and 110c. According to another example, if the elevator el ement to which the cleaning need is defined is an elevator car 106a-106n itself the use of said elevator car 106a-106n may be disabled and a visual and/or audio indication may be generated to indicate that said elevator car 106a-106n is out of operation, e.g. a text-based and/or symbol-based visual indication may be displayed e.g. on a display or screen at each floor above the landing door of said elevator car 106a-106n. According to another example, if the ele vator element to which the cleaning need is defined is at least one part of the elevator car 106a-106n, the use of the whole elevator car 106a-106n may be disabled and a visual and/or audio indication may be generated to indicate that said elevator car 106a-106n is out of operation, e.g. a text-based and/or sym bol-based visual indication may be displayed e.g. on a display or screen at each floor above the landing door of said elevator car 106a-106n.

According to an exemplifying embodiment of the invention, the method may al ternatively or in addition comprise receiving, by the elevator control unit 102, a cleaning accomplished information from the monitoring unit 114 and generat ing, by the elevator control unit 102, a second control signal to the at least one elevator element 108a-108n, 110a-110n, 106a-106n to which the cleaning need is defined, in response to receiving the cleaning accomplished infor mation. The second control signal may comprise instruction to re-enable the use of the at least one elevator element 108a-108n, 110a-110n, 106a-106n to which the cleaning need is defined. This is illustrated in Figure 2 with the op tional step 212.

Figure 4 schematically illustrates an example of components of the elevator control unit 102 according to the invention. The elevator control unit 102 may comprise a processing unit 410 comprising at least one processor, a memory unit 420 comprising at least one memory, a communication unit 430 compris ing one or more communication devices, and possibly a user interface (Ul) unit 440. The memory unit 420 may store portions of computer program code 425 and any other data, and the processing unit 410 may cause the elevator con- trol unit 102 to implement, i.e. perform, at least the operation, i.e. the method steps as described above by executing at least some portions of the computer program code 425 stored in the memory unit 420. For sake of clarity, the pro cessor herein refers to any unit suitable for processing information and control the operation of the elevator control unit 102, among other tasks. The opera tions may also be implemented with a microcontroller solution with embedded software. Similarly, the memory 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 unit 430 may be based on at least one known communication technologies, either wired or wireless, in order to exchange pieces of information as described ear lier. The communication unit 430 provides an interface for communication with any external unit, such as elevator entities e.g. the plurality of elevator user in terface devices 108a-108n, 110a-110n, the at least one elevator car 106a- 106n; the monitoring unit 114; one or more databases; and/or any external systems. The user interface 440 may comprise I/O devices, such as buttons, keyboard, touch screen, microphone, loudspeaker, display, screen and so on, for receiving input and outputting information. The computer program 425 may be stored in a non-statutory tangible computer readable medium, e.g. an USB stick or a CD-ROM disc.

The term “meet” in the context of the predefined threshold is used in this pa tent application to mean that a predefined condition is fulfilled. For example, the predefined condition may be that the predefined threshold is reached and/or exceed. 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.