Patent Publication Number: US-11661311-B2

Title: Elevator system

Description:
FOREIGN PRIORITY 
     This application claims priority to European Patent Application No. 18197166.4 filed Sep. 27, 2018, and all the benefits accruing therefrom under 35 U.S.C. § 119, the contents of which in its entirety are herein incorporated by reference. 
     BACKGROUND 
     The invention relates to an elevator system, in particular to an elevator system comprising at least one passenger sensor provided at least one of its landings. 
     An elevator system typically comprises at least one elevator car moving between a plurality of landings and landing control panels allowing passengers to enter their hall calls or destination calls for using the elevator system. 
     The landing control panels may be destination control panels inviting the passengers to enter their desired destination landing in order to allow the elevator system to optimize the transportation of the passengers, in particular if the elevator system comprises a plurality of elevator cars. 
     In case a group of passengers desires to use the elevator system together, usually only a single destination call is input via the landing control panel. 
     In order to allow the elevator system to optimize the transportation of groups of passengers, it would be beneficial to allow the elevator system to determine the size of a group entering a destination call in order to be able to control the elevator system accordingly. An optimized control in particular may include sending an elevator car having enough free space for accommodating all members of the group to the respective landing. 
     SUMMARY 
     Exemplary embodiments of the invention include an elevator system comprising an elevator car configured for traveling along a hoistway between a plurality of landings and at least one passenger sensor provided at least one of the landings. The at least one passenger sensor is configured for detecting passengers, i.e. one or more passengers, which are present within a detection zone defined at the respective landing, by detecting a detection signal reflected by a reflecting building structure at the respective landing. The at least one passenger sensor is further configured for providing a sensor signal related to the detected passengers. 
     It has turned out that using a detection signal, which has been reflected by a reflecting building structure of the respective landing, is beneficial for determining the number of passengers within a detection zone defined at a landing, particularly in front of a landing control panel. In particular, the risk that some of the passengers are not detected by the passenger sensor since they are covered by other passengers so that the detection signal is blocked, which would result in an erroneous sensor signal, is minimized 
     Thus, a sensor configured for providing a signal which is correlated with the number of passengers, i.e. a signal providing a measure of the number of passengers, at a landing can conveniently be arranged in or at an input terminal (“destination entry kiosks”) housing the respective landing control panel. It in particular is not necessary to modify the building structure for installing the sensor. 
     Exemplary embodiments of the invention further include a method of controlling an elevator system according to an exemplary embodiment of the invention, wherein the method includes controlling the movement of the at least one elevator car based on the sensor signal(s) provided by the at least one passenger sensor. 
     This allows controlling the elevator system based on destination calls entered at the landings in combination with considering the number of passengers associated with each of the entered destination calls in order to ensure that every elevator car assigned to a passenger or to a group of passengers has enough free space for accommodating all passengers assigned to said elevator car. This avoids a situation in which not all passengers assigned to a certain elevator car can enter said elevator car due to overload. Such a situation would severely compromise the advantages of using destination calls for controlling the elevator system and dispatching the elevator cars. . . . The elevator control may employ a certain buffer between the number of passengers assigned to an elevator car and the actual maximum load of the elevator car in order to avoid an overload in case not all passengers associated with a destination call are detected by the at least one passenger sensor. 
     A number of optional features are set out in the following. These features may be realized in particular embodiments, alone or in combination with any of the other features, unless specified otherwise. 
     The reflecting building structure may be located in an upper part of the respective landing. The reflecting building structure in particular may include a ceiling or a portion of a ceiling of the respective landing. Optionally, a reflector may be provided at the ceiling of the respective landing. 
     Using a reflecting building structure located in an upper part of the respective landing, i.e. above the passengers being present at the respective landing, reduces the risk that some of the passengers are not detected by the passenger sensor since they are shadowed/covered by other passengers. 
     Using the ceiling of the landing for reflecting the signals allows for an easy implementation at low costs. Using a dedicated reflector might enhance the quality and/or intensity of the reflection. This might enhance the reliability of the detection and/or allow using cheaper passenger sensors with reduced sensitivity. 
     The at least one passenger sensor may be configured for providing a signal which is correlated with the number of passengers present within the predefined detection zone. In other words, the at least one passenger sensor may be configured for providing a signal which is a measure of the number of passengers present within the predefined detection zone. The predefined detection zone may be located close to the landing control panel at the respective landing in order to identify and count only passengers related to a control command (destination call) currently input via the landing control panel. 
     The at least one passenger sensor may comprise at least one detector (passive device) which is configured for detecting radiation emitted by the passengers and being reflected by the reflecting building structure. Detecting radiation, such as heat or noise, emitted by the passengers allows for a low cost implementation, as there is no need of providing an emitter for emitting radiation which is to be reflected by the passengers. 
     Alternatively, the at least one passenger sensor may comprise at least one emitter (active device) configured for emitting a detection signal to be reflected by the reflecting building structure towards the predefined detection zone, and at least one detector configured for detecting a detection signal reflected from at least one of the passengers within the predefined detection zone via the reflecting building structure towards the detector. The emitter may be configured for emitting the radiation towards the reflecting building structure within a well-defined opening angle centered around a defined emission direction. 
     Using an emitter allows using a detection signal comprising radiation which is not emitted by the passengers themselves. In particular, signals in a selected frequency range, which allows for a very reliable detection of the passengers, may be used. 
     The detection signal may include electromagnetic radiation, such as visible light, infrared light and/or millimeter waves. The sensor signal also may include sound, such as ultrasound. 
     The at least one emitter and/or the at least one detector may be arranged at or in an input terminal, such as a destination entry kiosk, located at the respective landing and housing the respective landing control panel. The at least one emitter and/or the at least one detector in particular may be arranged at or in the same input terminal. 
     The at least one emitter and/or the at least one detector may have an opening angle, i.e. an angle in which the detection signal is emitted and/or received, which is in the range of 30° to 60°, in particular an opening angle of 45°. By modifying the opening angle of the detector, the size of the detection zone may be adjusted. The size of the detection zone in particular may be adjusted in order to detect substantially all passengers belonging to a group of passengers entering a destination call without detecting additional passengers, which are not part of said group. 
     The elevator system may comprise a controller, in particular a controller which is configured for destination dispatching. When destination dispatching is applied, passengers enter their desired destinations via the landing control panels before entering an elevator car. The controller then assigns each passenger or each group of passengers to a dedicated elevator car in order to optimize the transport capacity and the transport speed of the elevator system. In particular, passengers with the same destination may be assigned to the same elevator car for reducing the total number of stops of the elevator cars. 
     A method of controlling an elevator system in particular may include receiving a destination call at one of the landings; determining a measure of the number of passengers being present within the predefined detection zone at the respective landing from a sensor signal provided by a passenger sensor located at said landing; and controlling the movement of the at least one elevator car based on the received destination call and the determined measure of the number of passengers. 
     Destination dispatching using a sensor signal indicating a measure of the number of passengers associated with a currently entered destination call allows for a very efficient control of the elevator system; it in particular allows for an efficient dispatching of the elevator car(s) in response to hall calls or destination calls. 
    
    
     
       DRAWING DESCRIPTION 
       In the following, exemplary embodiments of the invention are described in more detail with respect to the enclosed figures: 
         FIG.  1    schematically depicts an elevator system to which an exemplary embodiment of the present invention may be applied. 
         FIG.  2    shows a schematic side view of a landing of an elevator system in which an exemplary embodiment of the present invention is employed. 
         FIG.  3    shows a schematic side view of a landing of an elevator system in which another exemplary embodiment of the present invention is employed. 
     
    
    
     DETAILED DESCRIPTION 
       FIG.  1    schematically depicts an elevator system  2  to which an exemplary embodiment of the present invention may be applied. 
     The elevator system  2  includes an elevator car  10  movably arranged within a hoistway  4  extending between a plurality of landings  8 . The elevator car  10  in particular is movable along a plurality of car guide members  14 , such as guide rails, extending along the vertical direction of the hoistway  4 . Only one of said car guide members  14  is visible in  FIG.  1   . 
     Although only one elevator car  10  is depicted in  FIG.  1   , the skilled person will understand that exemplary embodiments of the invention may include elevator systems  2  having a plurality of elevator cars  10  moving in one or more hoistways  4 . 
     The elevator car  10  is movably suspended by means of a tension member  3 . The tension member  3 , for example a rope or belt, is connected to a drive unit  5 , which is configured for driving the tension member  3  in order to move the elevator car  10  along the height of the hoistway  4  between the plurality of landings  8 , which are located on different floors. 
     Each landing  8  is provided with a landing door  11 , and the elevator car  10  is provided with a corresponding elevator car door  12  for allowing passengers to transfer between a landing  8  and the interior of the elevator car  10  when the elevator car  10  is positioned at the respective landing  8 . 
     The exemplary embodiment of the elevator system  2  shown in  FIG.  1    employs a 1:1 roping for suspending the elevator car  10 . The skilled person, however, easily understands that the type of the roping is not essential for the invention and that different kinds of roping, e.g. a 2:1 roping, may be used as well. The elevator system  2  may have a machine room or may be a machine room-less elevator system. The elevator system  2  may use a tension member  3 , as it is shown in  FIG.  1   , or it may be an elevator system without a tension member  3 . The drive  5  may be any form of drive used in the art, e.g. a traction drive, a hydraulic drive or a linear drive. 
     The elevator system  2  shown in  FIG.  1    further includes a counterweight  19  attached to the tension member  3  and moving concurrently and in opposite direction with respect to the elevator car  10  along at least one counterweight guide member  15 . The skilled person will understand that the invention may be applied also to elevator systems  2  which do not comprise a counterweight  19 . 
     The tension member  3  may be a rope, e.g. a steel wire rope, or a belt. The tension member  3  may be uncoated or may have a coating, e.g. in the form of a polymer jacket. In a particular embodiment, the tension member  3  may be a belt comprising a plurality of polymer coated steel cords (not shown). The elevator system  2  may have a traction drive including a traction sheave for driving the tension member  3 . 
     The drive unit  5  is controlled by a controller  6  for moving the elevator car  10  along the hoistway  4  between the different landings  8 . 
     Input to the controller  6  may be provided via landing control panels  7   a , which are provided on each landing  8  close to the landing doors  11 , and/or via an elevator car control panel  7   b , which is provided inside the elevator car  10 . 
     The controller  6  in particular may be configured for destination dispatching. When destination dispatching is applied, passengers  26  enter their desired destinations via the landing control panels  7   a  before entering an elevator car  10 . The controller  6  than assigns each passenger  26  to a dedicated elevator car  10  for optimizing the transport capacity and the transport speed of the elevator system  2 . In particular, passengers  26  with the same destination may be assigned to the same elevator car  10  for reducing the total number of stops of the elevator cars  10 . When destination dispatching is applied, usually no elevator car control panel  7   b  is used. 
     Each of the landing control panels  7   a  may be mounted to a wall  32  at the respective landing  8 . Alternatively, the landing control panels  7   a  may be located in input terminals  34  (see  FIG.  3   ) arranged in the vicinity of the respective landing doors  11 . The input terminals  34  in particular may be freestanding destination entry kiosks arranged in front of the landing doors  11 . 
     The landing control panels  7   a  and the elevator car control panel  7   b  may be connected to the controller  6  by means of electric wires, which are not shown in  FIG.  1   , in particular by an electric bus, such as a field bus/CAN-bus, or by means of wireless data connections. 
       FIGS.  2  and  3    respectively depict a schematic side view of a landing  8  of an elevator system  2  in which an embodiment of the present invention is employed. The landing  8  may be any landing  8  of the elevator system  2 . The landing  8  in particular may be a landing  8  located in the lobby of the building housing the elevator system  2 , or any other landing  8  for which a large passenger traffic is expected. 
     At least one passenger sensor  20  is provided at the landing  8 . The at least one passenger sensor is configured for detecting passengers  26  which are present within a detection zone  28  defined at the landing  8  by detecting a detection signal  30   b  reflected by a reflecting building structure  22 ,  24 , such as a ceiling  22  of the landing  8 . The at least one passenger sensor  20  in particular is configured for providing a sensor signal which is a measure of the number of passengers  26  detected within the detection zone  28 . 
     Optionally, the reflecting building structure  22 ,  24  may include a reflector  24  and/or a reflective coating, in order to enhance the reflection properties of the reflecting building structure  22 ,  24 . 
     Using a reflected detection signal  30   b  for detecting the passengers  26 , reduces or minimizes the risk of generating a wrong sensor signal because passengers  26  are not detected since they are shadowed by other passengers  26  so that the detection signal  30   b  is blocked. 
     As a result, the elevator system  2  may be controlled based on the number of detected passengers  26  in combination with a destination call entered at the respective landing  8  in order to optimize the transport capacity of the elevator system  2  and the user experience of the passengers  26 . In particular, only elevator cars  10  having enough free space for accommodating the whole group of passengers  26  standing within the detection zone  28  may stop at the landing  8  in order to avoid that the passengers  26  need to separate for entering different elevator cars  10 . 
     The at least one passenger sensor  20  may be mounted to a wall  32  at the landing  8 , as shown in  FIG.  2   . The at least one passenger sensor  20  may be located at or within an input terminal  34 , which comprises the landing control panel  7  and is arranged at the landing  8  in the vicinity of the landing door  11 , as it is shown in  FIG.  3   . 
     The at least one passenger sensor  20  may comprise at least one detector  36  configured for detecting radiation such as heat or noise emitted by the passengers  26  and being reflected by the structural component  22  or the reflector  24 . 
     The at least one passenger sensor  20  may further comprise at least one emitter  38  configured for emitting a detection signal  30   a  to be reflected by the reflecting building structure  22 ,  24  towards the predefined detection zone  28  and the at least one detector  36  may be configured for detecting a detection signal  30   b  reflected from at least one of the passengers  26  within the predefined detection zone  28 . 
     The at least one emitter  38  and/or the at least one detector  36  may have an opening angle in the range of 30° to 60°, in particular an opening angle of 45°. By modifying the opening angle of the detector  36 , the size of the detection zone  28  may be adjusted in order to detect preferably all passengers  26  of a group of passengers  26  entering a destination call without detecting additional passenger  26  which are not part of the group. 
     The detection signal  30   a ,  30   b  which is emitted by the at least one emitter  38  and/or detected by the at least one detector  36  may include electromagnetic radiation, in particular at least one of visible light, infrared light and millimeter waves. 
     The detection signal  30   a ,  30   b  emitted by the at least one emitter  38  and/or detected by the at least one detector  36  may also include sound, in particular ultrasound and/or sound generated by the passengers  26  within the detection zone  28 . 
     While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adopt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention shall not be limited to the particular embodiment disclosed, but that the invention includes all embodiments falling within the scope of the dependent claims. 
     REFERENCES 
       2  elevator system 
       3  tension member 
       4  hoistway 
       5  drive unit 
       6  controller 
       7   a  landing control panel 
       7   b  elevator car control panel 
       8  landing 
       10  elevator car 
       11  landing door 
       12  elevator car door 
       14  car guide member 
       15  counterweight guide member 
       17  braking member 
       19  counterweight 
       20  passenger sensor 
       22  reflecting building structure/ceiling 
       24  reflecting building structure/reflector 
       26  passengers 
       28  detection zone 
       30   a  emitted detection signal 
       30   b  detected detection signal 
       32  wall 
       34  input terminal 
       36  detector 
       38  emitter