The present invention relates to a method and a system for controlling an elevator system, particularly for controlling an elevator system for transporting passengers, and to an elevator system.

In conventional elevator systems, an elevator car drives to a selected floor, for example to receive or to release passengers. The elevator car may be driven to the selected floor in an elevator shaft based on position information of the elevator car. For example, EP 3 625 160 Bl and US 2017/0349399 Al relate to methods for determining the position of an elevator car. Conventionally, when the elevator car arrives at the selected floor, a car door of the elevator car and a shaft door of the selected floor are mechanically coupled and the shaft door is unlocked, after which the elevator car door and the shaft door are opened together and closed together. In particular, a door drive of the elevator car door is used to open and close the mechanically coupled elevator car door and the shaft door. However, opening an elevator car door and a shaft door based on mechanical coupling may be error-prone or slow.

Accordingly, there is a need for methods and systems for controlling an elevator system, which are improved with respect to conventional techniques, particularly with respect to reliability, safety and/or speed of opening the doors of an elevator system. Such needs are met with the subject matter of the independent claims. Advantageous embodiments are defined in the dependent claims and in the following specification.

In one aspect, a method of controlling an elevator system is provided. The elevator system includes an elevator car having an elevator car door and movable in an elevator shaft between a plurality of floors, wherein on each floor a shaft door is located. Each shaft door includes a predetermined marker. Further, the elevator car door includes a car door drive for opening and closing the elevator car door and each shaft door of the plurality of floors include a shaft door drive for opening and closing the respective shaft door.

In particular, the elevator car door and a shaft door are not mechanically coupled with each other when opening the elevator car door and the shaft door at a selected floor. Autonomous opening of the elevator car door and the shaft door can provide for example a faster opening of the doors and/or a less error-prone opening mechanism. Embodiments described herein may particularly provide a test on whether it is safe to open the elevator car door and the shaft door of the selected floor, particularly if the elevator car door and the shaft door are not mechanically coupled when opening the doors.

According to the invention, the method includes receiving a call request for a selected floor of the plurality of floors. The method further includes retrieving predetermined marker information for a shaft door of the selected floor from a database, the predetermined marker information being indicative of a predetermined marker of the shaft door of the selected floor. The method further includes moving the elevator car to a region of the elevator shaft, the region corresponding to the selected floor. The method includes reading, within the region, first marker information from a first marker of the predetermined markers. The method further includes verifying a consistency condition with respect to the first marker information and the predetermined marker information. The method includes opening the elevator car door and the shaft door of the selected floor if the consistency condition is satisfied. It should be understood that the method may include any additional features or steps according to embodiments described herein.

In another aspect, a system for controlling an elevator system is provided. The elevator system includes an elevator car having an elevator car door and movable in an elevator shaft between a plurality of floors, wherein on each floor a shaft door is located. The system includes a predetermined marker for each of the shaft doors. The system further includes a marker sensor configured to be mounted to the elevator car, the marker sensor configured for reading marker information from each of the predetermined markers. The system further includes a controller communicatively coupled to the marker sensor. The controller is configured for receiving a call request for a selected floor of the plurality of floors. The controller is further configured for retrieving predetermined marker information for a shaft door of the selected floor from a database, the predetermined marker information being indicative of a predetermined marker of the shaft door of the selected floor. The controller is configured for moving the elevator car to a region of the elevator shaft, the region corresponding to the selected floor. The controller is further configured for reading, within the region, first marker information from a first marker of the predetermined markers using the marker sensor. The controller is configured for verifying a consistency condition with respect to the first marker information and the predetermined marker information. The controller is further configured for opening the elevator car door and the shaft door of the selected floor if the consistency condition is satisfied. It should be understood that the system, particularly the controller, may be configured to perform any additional method steps according to embodiments described herein.

In yet another aspect, an elevator system is provided. The elevator system includes an elevator shaft with a plurality of floors, each floor including a shaft door. The elevator system further includes an elevator car movable in the elevator shaft between the plurality of floors. The elevator system further includes a system for controlling an elevator system according to embodiments described herein, wherein the marker sensor is mounted to the elevator car, and wherein each shaft door includes a predetermined marker. It should be understood that the elevator system may include any additional features of embodiments described herein.

According to some embodiments, the elevator system includes an elevator car movably arranged in an elevator shaft of the elevator system. In particular, the elevator car is movable in the elevator car between a plurality of floors, at which passengers may enter or exit the elevator car. The elevator car may be movable along a travel axis in the elevator shaft, e.g. along a vertical axis. In embodiments, each floor of the plurality of floors includes a shaft door. Passengers may enter and exit the elevator car at a floor through the shaft door of the floor and through an elevator car door of the elevator car. According to embodiments, a shaft door particularly includes a door frame positioned within a shaft wall of the elevator shaft at a floor of the elevator system. In embodiments, the shaft door includes at least one door leaf. The door leaf may be movable to open the shaft door.

According to embodiments of the present disclosure, a call request for a selected floor of the plurality of floors is received, particularly by a controller of a system or elevator system according to embodiments described herein. For example, a call request may be made by a passenger through elevator controls in the elevator car or at a shaft door. The call request may be indicative of a selected floor. For instance, the selected floor may be a destination chosen by a passenger within the elevator car. In another instance, the selected floor may be the floor at which a passenger is waiting for the elevator car.

After receiving the call request for the selected floor, a position of the selected floor within the elevator shaft may be retrieved. The position of a floor of the plurality of floors, particularly of the selected floor, may be retrieved from a position database, e.g. by the controller. The position of the selected floor may be the position of the selected floor along a travel axis of the elevator car in the elevator shaft with respect to a reference point, e.g. with respect to a maximum or minimum position of the elevator car in the elevator shaft. In embodiments, the position of the selected floor may correspond to the position of a shaft door of the selected floor.

In embodiments, the elevator car may move to a region of the elevator shaft, wherein the region corresponds to the selected floor. More specifically, the controller may control the elevator car to move to the region of the selected floor, the region particularly including the position of the selected floor retrieved from the position database. While moving the elevator car, the position of the elevator car may be monitored or controlled using a position determination system for determining the position of the elevator car within the elevator shaft. The position determination system may include a position determination sensor system. For example, the position determination system may include a magnetic sensor on the elevator car for reading a magnetic band positioned in the elevator shaft. The position of the elevator car may be determined based on a magnetic reading of the magnetic band. In further embodiments, the position determination system may include an optical sensor for determining the position based on an optical reading of a shaft component of the elevator shaft or based on images of the shaft component. In yet further embodiments, the position determination system may include a laser and a laser detector for determining the position of the elevator car with respect to a top or a bottom of the elevator shaft. In some embodiments, the position determination system may include an acceleration sensor on the elevator car for calculating the position of the elevator car based on a measured acceleration. In further embodiments, the position of the elevator car may be determined by any combination of position determination sensor systems. In embodiments, the controller may use the position determined via the position determination system for controlling the position and/or motion of the elevator car to the region of the selected floor.

In embodiments, the region of the selected floor may be understood as a region along the travel axis of the elevator car, particularly a region along the travel axis encompassing a shaft door of the selected floor. The region of the selected floor may be understood as a region along the travel axis from a lower end of the selected floor to an upper end of the selected floor. According to embodiments, an elevator system includes a plurality of floors, each of the plurality of floors having a shaft door, and wherein each shaft door has a predetermined marker. In some embodiments, each shaft door may have one predetermined marker. In further embodiments, each shaft door may have more than one predetermined marker.

In embodiments, the predetermined markers of the shaft doors of the elevator system are door-specific markers. In particular, the one or more predetermined marker of the selected floor may be different from other predetermined markers of the other floors, particularly unique with respect to the other predetermined markers of other floors. The predetermined markers may include one or more distinct markers for each shaft door of the elevator system. In some embodiments, each of the predetermined markers may be unique in the elevator system. It should be understood that, in addition to the elevator system having the plurality of floors with each of those floors having a marked shaft door, the elevator system may have additional floors or additional shaft doors which are not configured according to embodiments described herein. In further embodiments, all floors and/or all shaft doors of an elevator system may be configured as described herein.

According to embodiments, a database may include predetermined marker information for each of the shaft doors. The predetermined marker information for a shaft door may be indicative of one or more predetermined marker of the shaft door. In particular, the predetermined marker information may contain information identifying the predetermined marker of the corresponding shaft door. The predetermined marker information may indicate which one or more predetermined marker is expected by the controller to be located at the corresponding shaft door. In embodiments, the predetermined marker information is different for each of the shaft doors. For example, the predetermined marker information for a shaft door may include a code for the predetermined marker of said shaft door. The database may be communicatively coupled to the controller or may be stored in a memory of the controller. In particular, the controller can retrieve the predetermined marker information from the database.

In embodiments, predetermined marker information for a shaft door of the selected floor may be retrieved from the database, the predetermined marker information being indicative of a predetermined marker of the shaft door of the selected floor. The predetermined marker information may be retrieved after receiving the call request for the selected floor. In particular, the predetermined marker information may be retrieved before, after or during moving the elevator car to the region of the selected floor.

According to embodiments, marker information may be read from the predetermined markers. In particular, after moving the elevator car to the region of the selected floor, first marker information may be read from a first marker of the predetermined markers. Marker information may be read from a predetermined marker via a marker sensor mounted on the elevator car. The marker sensor may be configured for reading the predetermined markers. The marker sensor may be positioned on the elevator car such that the marker sensor can read the predetermined markers of the shaft doors of a plurality of floors. In particular, the marker sensor may be configured for reading a predetermined marker of a shaft door when, more particularly only when, the marker sensor is in a region of the floor corresponding to the shaft door. In embodiments, the marker sensor is communicatively coupled to the controller. According to some embodiments, the predetermined markers are configured to interact with the controller only via the marker sensor. In some embodiments, the predetermined markers may not be communicatively coupled to one or more shaft door drives of the shaft doors.

In some embodiments, the marker sensor includes an optical sensor. The predetermined markers may include visual markers. For example, the optical sensor may include an imaging sensor for imaging the predetermined markers, particularly visual markers. For example, an imaging sensor may be a camera. The imaging sensor may be configured for acquiring an image of a predetermined marker of a shaft door, particularly when the elevator car is in a region of a floor corresponding to the shaft door. For instance, the predetermined markers may include a visual marker such as a visual code, e.g. a barcode or a QR code. The visual code may be different for each shaft door. In particular, the visual codes may encode for different marker information for each shaft door. The visual code may be read by the controller via the optical sensor to determine the marker information of the visual marker. In further embodiments, the visual markers may include any symbols and/or images which may be imaged by the optical sensor and which may be mapped by the controller to the different shaft doors.

Additionally or alternatively, in some embodiments the predetermined markers may include radio frequency markers, e.g. radio-frequency identification (RFID) tags or Bluetooth markers. The marker sensor may include a radio frequency sensor for reading the radio frequency markers. The radio frequency markers may be passive or active markers. The radio frequency marker of a shaft door may be configured for providing a door-specific radio frequency signal. The door-specific radio frequency signal may be read by the marker sensor when the elevator car is in the region of the shaft door, particularly for determining marker information of the radio frequency marker.

According to embodiments, the predetermined markers are provided on one or more shaft door components of the shaft doors. The one or more shaft door components may include a shaft door leaf and/or a door frame. In some embodiments, a predetermined marker may be provided on the shaft door by fabricating the predetermined marker as part of the shaft door. For example, a visual marker may be fabricated in a shaft door component by laser writing. In further embodiments, a predetermined marker may be positioned on the shaft door, particularly by attaching the predetermined marker to the shaft door, e.g. using an adhesive or a fastener.

In some embodiments, more than one predetermined marker may be provided on a shaft door. For example, a predetermined marker may be provided at an upper position of the shaft door. A further predetermined marker may be provided at a lower position of the shaft door. The more than one predetermined markers of a shaft door may be the same or may provide the same marker information, when read via the marker sensor. In further embodiments, the more than one predetermined markers may be different, particularly provide different marker information. The database may associate the different predetermined marker information with the same shaft door.

According to some embodiments, more than one marker sensor may be positioned on the elevator car, for example at an upper position and at a lower position of the elevator car. Providing more than one predetermined marker per shaft door and/or more than one marker sensor on the elevator car may provide an early reading of a first marker when the elevator car enters the region of the selected floor, particularly when entering the region in either travel direction of the elevator car along the travel axis.

In embodiments, the controller reads marker information from a predetermined marker, particularly first marker information from the first marker within the region of the selected floor. The marker information may be suitable to identify the corresponding predetermined marker, particularly to distinguish the predetermined marker of the corresponding shaft door from predetermined markers of other shaft doors. For example, the first marker information may be suitable to identify the first marker, particularly to distinguish the first marker of the shaft door of the selected floor from other shaft doors, more specifically from other shaft doors of other floors of the elevator system. In embodiments, the marker information read from a predetermined marker may include a code for the predetermined marker.

According to embodiments, a consistency condition with respect to the first marker information and the predetermined marker information is verified. The consistency condition may be provided for determining whether the first marker corresponds to the predetermined marker indicated by the predetermined marker information. In particular, the consistency condition may provide a test on whether the first marker corresponds to an expected predetermined marker for the shaft door of the selected floor. In embodiments, the consistency condition being satisfied indicates that the first marker corresponds to the predetermined marker indicated by the predetermined marker information.

For instance, the predetermined marker information for a certain shaft door stored in the database may correspond to or may be at least partially the same as the marker information readable from a predetermined marker of said certain shaft door via the marker sensor. In such a case, verifying the consistency condition may include comparing the predetermined marker information and the marker information read via the marker sensor. The consistency condition is satisfied if the predetermined marker information from the database and the marker information read via the marker sensor correspond or are at least partially the same. Otherwise, the consistency condition is not satisfied.

However, the subject matter is not limited to such a comparison. For example, the predetermined marker information of a certain shaft door and the marker information read from a predetermined marker of said certain shaft door may be different. The predetermined marker information and the marker information readable from the predetermined marker may be chosen such that the consistency condition is satisfied, if the outcome of a computation corresponds to an expected predetermined outcome. The computation may for example include the calculation of a sum. In case of a different outcome, the consistency condition is not satisfied. It should be understood that a consistency condition according to the present disclosure may be formulated in a variety of ways.

According to embodiments, the elevator car door and the shaft door of the selected floor are opened if the consistency condition is satisfied, particularly only if the consistency condition is satisfied. The controller may be configured not to open the elevator car door and the shaft door of the selected floor if the consistency condition is not satisfied.

In some embodiments, the elevator car door includes a car door drive for opening the elevator car door. In particular, the one or more shaft doors of the plurality of floors may each include a shaft door drive. In embodiments, the elevator car door and the shaft door of the selected floor are not mechanically coupled for opening the elevator car door and the shaft door of the selected floor. In particular, the elevator car door and the shaft door of the selected floor may be opened autonomously, specifically without being mechanically coupled to one another. Opening the elevator car door and the shaft door of the selected floor may include controlling the car door drive to open the elevator car door, and controlling the shaft door drive of the selected floor to open the shaft door of the selected floor if the consistency condition is satisfied.

According to some embodiments, the elevator car may include more than one elevator car door. The elevator car may include a first elevator car door on a first side of the elevator car and a second elevator car door on a second side of the elevator car. The elevator system may include shaft doors on a plurality of floors, wherein each floor includes one or more shaft door on the first side and/or on the second side of the elevator car. In embodiments, the elevator car may have a first marker sensor on the first side of the elevator car, particularly for reading predetermined markers of shaft doors, the shaft doors being arranged on the first side of the elevator car. The elevator car may have a second marker sensor on the second side of the elevator car, particularly for reading predetermined markers of further shaft doors, the further shaft doors being arranged on the second side of the elevator car.

In embodiments with more than one elevator car door, operations of methods or controllers disclosed herein may be performed for each of the first side and the second side of the elevator car, particularly the operations of retrieving predetermined marker information, reading first marker information from a first marker in the region of the selected floor, verifying a consistency condition, and opening the elevator car door and the shaft door. For example, the controller may retrieve predetermined marker information for a shaft door on the first side of a selected floor. The controller may read, within the region of the selected floor, first marker information from a first marker on the first side of the elevator car, particularly via the first marker sensor. The controller may verify a consistency condition with respect to the first marker information and predetermined marker information for the shaft door. The controller may open the first elevator car door and the shaft door on the first side, if the consistency condition for the first side is satisfied.

Further, the same selected floor or a different selected floor of the elevator system may include a further shaft door on the second side of the elevator car, the further shaft door having a second marker of the predetermined markers. The controller may retrieve predetermined marker information for the further shaft door. The controller may read, within the region of the selected floor, second marker information from the second marker, particularly via the second marker sensor. The controller may verify a consistency condition with respect to the second marker information and the predetermined marker information for the further shaft door of the selected floor. The controller may open the second elevator car door and the further shaft door on the second side, if the consistency condition for the second side is satisfied.

For some selected floors, the database may indicate that no shaft door is present on at least one side of the elevator car, no predetermined marker information may be retrievable for the at least one side and/or no predetermined marker may be readable on the at least one side. In such instances, the controller may be configured not to open the elevator car door on the at least one side. If a shaft door is present on the at least one side of the selected floor, the controller may be configured not to open the shaft door on the at least one side.

According to some embodiments, the predetermined marker information is acquired during a learning travel of the elevator car. During the learning travel, predetermined marker information may be acquired for each shaft door of the plurality of floors. In particular, predetermined marker information is acquired for the shaft door of the selected floor, for which a call request is received according to embodiments described herein. The learning travel may be performed particularly prior to receiving a call request according to embodiments. For example, a learning travel may be performed during commissioning of the elevator system or during a service operation for the elevator system. In the learning travel, the predetermined marker information may associate each shaft door with one or more predetermined markers provided on the shaft door. The predetermined marker information may be stored in a database according to embodiments described herein.

In some embodiments, a system for controlling an elevator system includes a controller. The controller may be a main elevator controller. The controller may be communicatively coupled to a marker sensor according to embodiments described herein. In embodiments, the controller is communicatively coupled to an elevator car door drive of the elevator car door, the elevator car door drive being configured for opening and/or closing the elevator car door. The controller may be communicatively coupled to shaft door drive a shaft door, particularly to the shaft door drive of each shaft door of the plurality of floors. The shaft door drive of a shaft door may be configured for opening and/or closing the shaft door. Via the communicative coupling, the controller may control or signal a door drive to open a respective door. In embodiments, the controller is communicatively coupled to a position determination system and/or an elevator drive for moving the elevator car along the travel axis of the elevator car. The controller may control the elevator car to move according to embodiments described herein, e.g. to move to a selected floor. The controller may further be communicatively coupled to elevator controls in the elevator car and/or at the shaft doors, particularly for receiving call requests.

In embodiments, the controller may include a central processing unit (CPU) and/or a computer-readable medium or memory and, for example, support circuits. To facilitate control of the elevator system, the CPU may be one of any form of general purpose computer processor that can be used for controlling various components and sub-processors. The computer-readable medium or memory is coupled to the CPU. The computer readable medium or memory may be one or more readily available memory devices such as random access memory, read only memory, flash memory, hard disk, or any other form of digital storage either local or remote. A database and/or a position database according to embodiments may be stored in a local or remote memory of the controller. The support circuits may be coupled to the CPU for supporting the processor in a conventional manner. These circuits include cache, power supplies, clock circuits, input/output circuitry and related subsystems, and the like. Instructions for controlling an elevator system are generally stored in the computer-readable medium as a software routine typically known as a recipe. The software routine, when executed by the CPU, transforms the general purpose computer into a specific purpose computer (controller) that controls the elevator system according to any of the embodiments of the present disclosure. Although the method of the present disclosure is discussed as being implemented as a software routine, some of the method operations that are disclosed herein may be performed in hardware as well as by the software controller. As such, the embodiments may be implemented in software as executed upon a computer system, and hardware as an application specific integrated circuit or other type of hardware implementation, or a combination of software and hardware. In particular, the controller may execute or perform a method of controlling an elevator system according to embodiments of the present disclosure.

Embodiments of the present disclosure relate to methods and systems for controlling an elevator system, which can provide a safe mechanism for opening an elevator car door and a shaft door of a selected floor. Methods and systems may check whether the elevator car is positioned in a region of the selected floor, particularly such that the shaft door of the selected floor and the elevator car door can be safely opened. Embodiments may be particularly advantageous for ensuring safety in elevator systems with separate elevator car door drive and shaft door drives, more specifically if the doors are not mechanically coupled for opening the doors like in conventional elevator systems. Embodiments may particularly enable safe, fast and/or reliable opening of the doors.

Reference will now be made in detail to various embodiments, one or more examples of which are illustrated in the figures. Within the following description of the drawings, the same reference numbers refer to same components. Generally, only the differences with respect to individual embodiments are described. Each example is provided by way of explanation and is not meant as a limitation. Further, features illustrated or described as part of one embodiment can be used on or in conjunction with other embodiments to yield yet a further embodiment. It is intended that the description includes such modifications and variations.

Fig. 1 shows a schematic view of an elevator system according to the present disclosure;

Fig. 2 illustrates a system for controlling an elevator system according to an embodiment; and Fig. 3 shows a flow diagram of a method according to the present disclosure.

Fig. 1 illustrates a schematic view of an elevator system 1. The elevator system 1 includes an elevator car 3 which is movable in an elevator shaft 21 between a plurality of floors 33 of the elevator system 1. In Fig. 1, each floor 33 of the plurality of floors 33 includes a shaft door 35 having a shaft door frame and a shaft door leaf. Each shaft door 35 can be opened and closed using a shaft door drive 41 arranged at the respective shaft door 35. Each shaft door 35 further includes a predetermined marker, wherein the predetermined markers are different for each of the plurality of floors 33. In particular, a first marker 45 of the predetermined markers is different from further markers 47 of the predetermined markers of other floors 33. In Fig. 1, the predetermined markers are provided for example at an upper position on the shaft door frames of the shaft doors 35. However, it should be understood that in further embodiments, the predetermined markers may be positioned at a different position of the shaft door, e.g. on the door leaf. In the example of Fig. 1, the predetermined markers are visual markers which are readable by a marker sensor 9 arranged on the elevator car 3, the marker sensor 9 being an optical sensor. The elevator car 3 further includes an elevator car door 5 which can be opened by an elevator car door drive 15 of the elevator car 3.

Referring to Figs. 1 and 2, a system 51 for controlling the elevator system 1 is illustrated, the system 51 including a controller 11, which is communicatively coupled via a communicative connection 13 to the shaft door drives 41 and to the elevator car door drive 15. Further, the controller 11 is communicatively coupled to an elevator drive 23, the elevator drive 23 being configured to move the elevator car 3 between the plurality of floors 33 along a travel axis 7 of the elevator car 3, particularly along a vertical axis. The controller 11 is further communicatively coupled to a position determination system 27 configured for determining the position of the elevator car 3 along the travel axis 7. The controller 11 uses the determined position and the elevator drive 23 to move the elevator car 3 to a target position within the elevator shaft 21, such as to a position of a floor selected via a call request by a passenger. Call requests may be received by the controller 11 from elevator controls 37 on the plurality of floors 33 and/or in the elevator car 3. Further, the controller 11 is communicatively coupled to the marker sensor 9 on the elevator car 3, the marker sensor 9 being configured for reading the predetermined markers such as the first marker 45. The controller 11 might be located in a machine room of the elevator system, in a shaft head or on the elevator car 3.

Fig. 3 illustrates a flow diagram of a method 100 according to embodiments. At block 110, the method 100 includes receiving a call request for a selected floor 31. For example, the controller 11 of Figs. 1 and 2 receives a call request via elevator controls 37 for a selected floor 31, e.g. to receive or release passengers on the selected floor 31. At block 120, the method 100 includes retrieving predetermined marker information for a shaft door 35 of the selected floor 31 from a database 53. For example, the predetermined marker information for the shaft door 35 of the selected floor 31 includes a predetermined code. At block 130, the elevator car 3 is moved to a region of the elevator shaft 21, the region corresponding to the selected floor 31. In particular, the controller 11 of the elevator system 1 retrieves a position of the selected floor 31 from a position database and controls the elevator drive 23 to move the elevator car 3 to the region of the selected floor 31, specifically to the position of the selected floor 31 within the region of the selected floor 31.

At block 140, the method 100 includes reading, within the region of the selected floor 31, first marker information from a first marker 45. For example, referring to Figs. 1 and 2, the controller 11 reads the first marker 45 using the marker sensor 9. Specifically, the visual marker is scanned or imaged using the optical sensor of the marker sensor 9 to determine a first code from the scan or image of the visual marker. At block 150, the method includes verifying a consistency condition with respect to the first marker information and the predetermined marker information. For instance, verifying the consistency condition includes a comparison of the first marker information and the predetermined marker information, the consistency condition being satisfied if the first marker information and the predetermined marker information are the same. In particular, the predetermined code of the predetermined marker information and the first code read from the first marker are compared.

At block 160, the elevator car door 5 and the shaft door 35 are opened if the consistency condition is satisfied. In particular, the controller 11 controls the elevator car door drive 15 and the shaft door drive 41 of the shaft door 35 of the selected floor 31 to open the elevator car door 5 and the shaft door 35 of the selected floor 31, if the predetermined code and the first code are the same. Otherwise, the elevator car door 5 and the shaft door 35 remain closed. Even though the method 100 exemplarily uses a comparison for verifying the consistency condition, it should be understood that in other embodiments according to the present disclosure, a different consistency condition may be used. Opening the elevator car door 5 and the shaft door 35 only if the consistency condition is satisfied can ensure that the elevator car door 5 and the shaft door 35 are only opened when the elevator car door is in the region or at the position of the selected floor. More specifically, risks for injuries of passengers can be reduced, e.g. risks of a shaft door or an elevator door opening into the elevator shaft. Thus, embodiments can particularly increase the safety of elevator operation.