Patent Publication Number: US-2021163263-A1

Title: Stair lift and method of operating a stair lift

Description:
The invention relates to a stair lift comprising a movable user carrier and to a method of operating a stair lift comprising a movable user carrier. 
     A stair lift is a product which is typically meant for people with impaired mobility, mostly elderly people, to provide a means to get upstairs and downstairs without removing the staircase and thus maintaining the functionality of the stairs for persons which can climb the stairs themselves. The stair lift is in most cases installed in people&#39;s homes and typically comprises a user carrier, as for example a chair or a wheel chair platform, driven by a drive unit which is arranged to drive the user carrier along the rail, mounted on or along one or more flights of a staircase. 
     Patent document WO 2005/087644 discloses a stair lift equipped with an automatic swivel functionality, which rotates the chair of the stairlift around a vertical axis during the ride in order to be able to move through narrow staircases. 
     This swivelling functionality can also be used in embarking stations, to rotate the chair away from the staircase flight before the user steps on or off the chair. These swivelling functionalities and also the speed profile of the chair can be programmed in the drive unit but are linked to the position of the drive on the rail of the stair lift. 
     Stair lifts, however, can also be installed in a staircase which provides access to multiple homes and can be used by different users. Some of these users might consider following the programmed swivelling functionalities and speed profile of the chair throughout several flights of the staircase inconvenient. 
     Therefore, an objective of the invention is to provide a stair lift and method of stairlift operation better adapted to different users&#39; needs and/or requirements. 
     This task is solved by a stair lift comprising the features of claim  1  and a method of operating a stair lift comprising the features of claims  6 . Advantageous embodiments of the invention are subject of the dependent claims. 
     According to one aspect, the invention provides a stair lift, comprising a) a movable user carrier, b) an authentication device comprising a signal receiver and at least two signal emitters, wherein each emitter is assigned to a different user of the stairlift, c) operation adjustment means, for generating a behavioral profile of the stair lift, d) a control unit for controlling the stairlift, particularly for controlling the authentication device and the operation adjustment means. 
     The control unit is arranged to adjust the behavioral profile of the stair lift, particularly of the user carrier, depending on the signal emitter authenticated by the authentication device, particularly based on which of the signal emitters has been authenticated. Particularly, a signal emitter is considered authenticated after making the respective contact with the signal receiver. The period in which the authentication stays valid may be determined by a certain amount of time, a continuing presence of the signal receiver and/or a subsequent authentication of the different signal emitter, according to different embodiments. 
     According to another aspect, the invention provides a method of operating a stair lift, particularly of a stairlift according to an embodiment of the invention, comprising at least the steps of: i) authenticating a signal emitter assigned to a certain user, ii) adjusting the behavioral profile of the stair lift, particularly of the user carrier, depending on the authenticated signal emitter (i.e. particularly depending on which of the signal emitters has been (and is still) authenticated). 
     The invention is based on the finding that different users of a stairlift in a certain staircase may desire different modes of operation whilst using the stairlift. The desired differences in stairlift operation might be with respect to movement details of the user carrier, aspects of the stair lift&#39;s human machine interface, or providing personalized safety features. 
     For example: in case one user lives on the 4th floor of a staircase and the user starts his/her ride on the stairlift on the ground floor, it might be convenient for the user to swivel (swivel=rotate around a vertical axis or an axis with a vertical component) the chair in front of his/her own front door on the 4th floor, but not at each intermediate floor between the other flights of the staircase. It might also be convenient for that user to ride at a relatively large speed of the user carrier without stopping the drive at each intermediate floor. For a different user living on the 2 nd  floor it might be convenient to rotate the chair only at the 2 nd  floor and travel at a lower speed for instance. 
     The invention offers the idea of combining authenticating a user (who wants his ride using the stair lift adapted to his needs/requirements/desires) and providing an adaptation infrastructure (i.e. operation adjustment means) for influencing different kinds of operational behavior of the stair lift. According to an embodiment of the invention, a control infrastructure is therefore provided that allows for the operation adjustment means to be controlled in a way it suits the specifications provided by the user that is currently authenticated. 
     Once a certain user has been authenticated as the current user of the stair lift, the operation adjustment mean(s) relevant to adjust the behavioral aspects of the stair lift that are relevant to the user&#39;s behavioral profile, can be adjusted deploying the control unit. For the invention to function, it is not necessary that a certain number or all operation adjustment means are deployed for adjusting the behavioral profile. 
     Particularly, the information on the aspects of the behavioral profile that are relevant to the user and on the specific characteristics the user requires/desires have been accumulated and stored in a database the control not means has access to. Filling such a database with respect to a certain user&#39;s preferences particularly can be performed before the use of the stair lift, for example during a sign-up process of/for the user. 
     For being able to adjust different aspects of the behavioral profile of the user carrier, the operation adjustment means can comprise different types of adjustment means. According to an embodiment, the operation adjustment means comprise
         movement adjustment means, particularly with respect to swivelling, tilting (tilting=rotating around a horizontal axis or an axis with a horizontal component) and/or speed of the user carrier, for generating a movement profile of the user carrier, and/or   interaction adjustment means, particularly with respect to adjusting a language or a mode or a style of an interaction interface of the user carrier, for generating an interaction profile of the user carrier, and/or   surroundings adjustment means, particularly with respect to lighting of the user carrier&#39;s surrounding, for generating a surroundings profile of the user carrier.       

     In order for the invention to be used with different types of stair lifts, the user carrier according to an embodiment comprises a chair and/or a wheelchair platform and/or a standing platform. A user carrier having a standing platform can support a user by transporting him/her standing on the platform and/or by providing support with respect to leaning and/or resting their arms and/or their back and/or their sides on the platform while walking up or down the stairs themselves. The latter concept itself is also referred to as a stair walker. Without limiting the scope of the invention, the invention is described for a stair lift having a swivelable and/or tiltable chair in the following. 
     According to an embodiment, the authentication device is of an RFID authentication type. Particularly, the signal receiver of the authentication device comprises an RFID tag reader and the signal emitters of the authentication device each comprise an RFID tag, wherein each of the RFID tags has a different ID, which is particularly distinguishable by the RFID tag reader. 
     The term “authentication device” is to be understood in a broad sense, particularly also including authentication means/methods that do not require separate hardware, as for example an authentication of biometric features, for example a finger print or an iris scan, but instead deploying hardware that is present at the stairlift anyway, for example a touchscreen or a camera. According to an embodiment, the authentication device can be any kind of one-lock multiple-keys system, deploying a wireless and/or physical lock and different wireless and/or physical keys. 
     To provide simple and quick authentication, according to an embodiment the signal receiver is arranged at, particularly attached to, the user carrier, particularly at an armrest. In case longer-range RFID components are used, the signal receiver may also be arranged at, particularly attached to, a backrest or a seat or a platform of the user carrier. 
     According to different embodiments, there are different aspects of the behavioral profile of the stairlift prone to be adjusted within the scope of the invention. Particularly, adjusting behavior of the stair lift may include movement aspects and/or interaction aspects and/or surroundings aspects. By covering one of these aspects, a very precise adjustment of the stair lift&#39;s operation can be attained; by covering more of these aspects, a more general adjustment. 
     Below, several types of operation adjustment means for adjusting the behavioral profile are described exemplary. According to an embodiment, each of these adjustment means can be applied separately or combined with one or more of the other adjustment means. 
     In order to adjust the way the user carrier moves through the staircase, according to an embodiment adjusting the behavioral profile comprises adjusting a movement profile of the stair lift. 
     Particularly, adjusting the movement profile comprises adjusting a stair lift speed profile. Thus, different levels of confidence with respect to travel speed in the staircase existing in different uses can be considered. Particularly, a speed of the movement of the user carrier along the guidance rail can be adjusted according to the user&#39;s preferences, for example separately for in-flight travel and on-floor travel. Particularly, different speed patterns can be applied on floors that are irrelevant to the user on the one hand and floors that are relevant to the user on the other hand. Exemplarily, a speed profile might include a stop at the designated arrival floor, but no stop on floors between the starting floor and the arrival floor. 
     Additionally or alternatively, adjusting the movement profile comprises adjusting a swivelling profile of the user carrier. Particularly, a swivelling movement of the user carrier may be applied during in-flight travel in case of a narrow passage in the staircase in order to avoid a collision of the user with a staircase wall or the like. Particularly, such swivelling adjustment is applied depending on certain body size or proportion features of the user. Thereby, the movement profile of a taller user might for instance comprise more swivelling than the movement profile of a smaller user. 
     Particularly, the user carrier can be swivelled on a certain floor, especially to swivel the user away from the neighboring flight of stairs and/or to direct the user towards his probable direction of exiting the user carrier. 
     Additionally or alternatively, adjusting the movement profile comprises adjusting a tilt profile of the user carrier. Particularly, a tilting movement of the user carrier may be applied during in-flight travel in case of a narrow passage in the staircase in order to avoid a collision of the user with the wall or the like. Particularly, such a tilting adjustment is applied depending on certain body size or proportion features of the user. Thereby, the movement profile of a taller user might comprise more tilting than the movement profile of a smaller user. Tilting can also be used for facilitating user ascent on the user carrier and descent from the user carrier. 
     According to an embodiment, the movement profile comprises a combined adjustment of a swivelling and tilting profile of the user carrier. 
     In order to adjust the way the user carrier interacts with the staircase it moves through and/or affects the staircase or other components surrounding it, according to an embodiment adjusting the behavioral profile comprises adjusting a surroundings profile of the stairlift. 
     Particularly, adjusting the surroundings profile comprises adjusting a stair lift lighting, particularly its brightness profile and/or its lighting pattern. Thus, a visually impaired user of the stairlift for example can be provided with sufficient lighting to visually percept the surroundings of the user carrier. 
     In order to adjust the way the user carrier interacts with the authenticated user, according to an embodiment adjusting the behavioral profile comprises adjusting an interaction profile of the stair lift. 
     Particularly, adjusting the interaction profile comprises adjusting emergency details, particularly telephone numbers to be contacted in case of a user emergency, and/or adjusting a voice signal profile, particularly for user information. Such features allow for improving passive safety of the authenticated user and/or improving human machine interaction. 
     To make sure the stairlift can be operated by non-authenticated users, a standard behavioral profile is (re-)applied in case no signal emitter is authenticated, particularly during an anonymous use and/or in case an authenticated signal emitter is removed. Especially in public staircases, such a feature is useful in order to provide personalized rides for frequent users (or known users that can be authenticated using a personal signal emitter linked to their personal behavioral profile that has been previously stored in the stair lift&#39;s control unit), but also normal rides for unknown chance users. 
    
    
     
       Further features, advantages and application of the invention result from the description below referring to the figures. 
         FIG. 1  shows a stair lift according to an exemplary embodiment of the invention, wherein only the user carrier and the corresponding section of a guiding rail is depicted; 
         FIG. 2  shows the stair lift of  FIG. 1  depicted in an exemplary flight of an exemplary stair case; 
         FIG. 3  shows a flow chart depicting the steps of a method of operating the stair lift  FIGS. 1 and 2  according to an exemplary embodiment; and 
         FIGS. 4 a  and 4 b    show the stair lift according to the previous figures operated by the method of  FIG. 3 , depicted for a first user and a second user. 
     
    
    
     In  FIG. 1 , a stair lift  1  is shown. The stair lift comprises a movable chair deployed as a user carrier  2 . In different embodiments, the user carrier  2  can also be a wheel chair platform or a standing platform. 
     The stair lift also comprises an authentication device  4  for comprising a signal receiver  6  and a number of signal emitters  8 , wherein each emitter  8 . 1 ,  8 . 2 ,  8 . n  is assigned to a different user U 1 , U 2 , Un (c.f.  FIGS. 3 and 4 ) of the stair lift  1 . In the exemplary embodiment, the signal receiver  6  is an RFID tag reader, and the signal emitters  8  are RFID tags that can be authenticated by the RFID tag reader  6 . 
     The stair lift further comprises operation adjustment means for generating a behavioral profile  12  of a stair lift  1 , particularly of the user carrier  2 . The operation adjustment means comprise a rail drive  14  for driving the user carrier  2  alongside the guiding rail  15  of the stair lift  1 , a swivelling and tilting drive  16  for swivelling and tilting the user carrier  2  with respect to a lift body  17  connecting to the guiding rail  15  via the rail drive  14 . The operation adjustment means further comprise lighting  18  for lighting the stair case in which the user carrier  2  travels, at least one speaker  20  for communication from the stair lift to the user, and a user interface  22  for entering commands by the user and/or displaying information to the user and/or emergency assistance personnel. 
     Stair lift  1  further comprises a control unit  24  for controlling the stair lift  1 . Control unit  24  comprises an authentication controller  26  which is connected to the signal receiver  6 , to a database  28  and to an operation controller  30 . 
     In database  28 , user profiles (c.f. reference signs U 1 , U 2  and Un) are stored, each of which is linked to one of the signal emitters  8 , wherein each of the signal emitters  8 . 1 ,  8 . 2 ,  8 . n  is assigned to a different user U 1 , U 2  or Un. 
     The operation controller  30  is connected to the operation adjustment means  14 ,  16 ,  18 ,  20  and/or  22 , and is configured to apply control commands to each of these operation adjustment means. 
     The control unit  24  is also arranged to adjust the behavioral profile  12  (c.f.  FIG. 3 ) of the stair lift  1  depending on which of the signal emitters  8 . 1 ,  8 . 2  or  8 . n  have been authenticated by the authentication device  4  using signal receiver  6 . 
     The stair lift  1  can be moved through a stair case  40  in both directions along the guiding rail  15 , following a rail axis R using the rail drive  14 . 
     By deployment of the swivelling and tilting drive  16 , the user carrier  2  can perform a swivelling movement  32  around its vertical axis V. User carrier  2  can also perform tilting movements  34 ,  36  around its orthogonal horizontal axes H 1  and H 2 . 
       FIG. 2  shows the stair lift  1  of  FIG. 1  in an exemplary installation environment, wherein the installation environment is a stair case  40 . In  FIG. 2 , one flight  42  between a lower floor  44  and an upper floor  46  is depicted. The figure shows a first apartment front door  48  on the left side of the user carrier  2  on the lower floor  44 . It also shows a second apartment door  50  on the rear side of the user carrier  2  on the higher floor  46 . 
     Stair case  40  comprises several additional flights of stairs, that are not depicted in  FIG. 2 . Stair lift  1  can travel throughout the stair case  40  along the guiding rail  15  and its axes R, wherein the guiding rail is particularly mounted in a typical way for known stairlifts (see also  FIG. 4 ). In  FIGS. 3 and 4 , an exemplary embodiment of a method of operating the stair lift according to  FIGS. 1 and 2  is described. 
       FIG. 3  particularly depicts the logic within the control unit  24  when performing the method;  FIGS. 4 a  and 4 b    depict two examples of performing the method for different authenticated users U 1 , U 2 . 
     In step S 10 , the current user of the stair lift  1  is authenticated. Therefore, the signal receiver  6  of authentication device  4  is in a receive mode. Once a signal emitter  8  is placed in receive area, authentication controller  26  detects the corresponding user. In the example of  FIG. 3 , user U 2  is authenticated. 
     In step S 20 , a user profile of the authenticated user U 2  is loaded (i.e. made available) to the operation controller  30 . The user profile of user U 2  is one several user profiles stored in database  28 . Each of the user profiles comprises the preferences of the respective user for a movement profile  60 , a surroundings profile  70  and/or an interaction profile  80 . A movement profile  60  comprises a stair lift speed profile  62 , a swivelling profile  64  of the user carrier  2  and/or a tilting profile  66  of the user carrier. The surroundings profile  70  of the stair lift  1  comprises a lighting brightness profile  72  and a lighting pattern  74 . The interaction profile  80  of the stair lift comprises emergency details  82  and/or a voice signal profile  84 . 
     With the user profile user U 2  loaded in step S 20 , step S 30  is applied. In step S 30  the behavioral profile  12  of the stair lift  1  is adjusted by applying the preferences stored in user profile U 2  to the operation adjustment means  14 ,  16 ,  18 ,  20  and  22  via the control unit  24 . 
     Thereby, the operation of stair lift  1  can be adjusted to the needs, preferences and/or requirements of the user U 2 . 
     In  FIG. 4 , different swivelling profiles  64  are depicted for the preferences of user  2  ( FIG. 4 a   ) and user  1  ( FIG. 4 b   ). 
     Stair case  40  of  FIG. 2  is depicted in  FIG. 4  from a top view perspective. In each of  FIGS. 4 a  and 4 b   , the stair lift  1  is shown at a position on floor  44 , at a position in stair case flight  42  and at a position on floor  46 . 
     In  FIG. 4 a   , the user profile of user U 2  is applied (as in  FIG. 3 ), since the signal emitter  8 . 2  personalized for user U 2  is currently authenticated. 
     User U 2  lives on floor  44  in the apartment with front door  48 . Therefore, the swivelling profile  64 . 2  of user U 2  comprises swivelling the user carrier  2  around the vertical axis V towards door  48  in order to facilitate an easy getting off the user carrier  2  for the user U 2 . This swivelling movement is indicated by arrow A. In contrast, on floor  46 —where user U 2  normally does not exit the user carrier  2 , no swivelling will take place, according to swivelling profile  46 . 2 . 
     In  FIG. 4 b   , user U 1  is authenticated as current user of the stair lift  1 , since the signal emitter  8 . 1  personalized for user U 1  is currently authenticated. User U 1  has different preferences, so a different swivelling profile  64 . 1  applies. 
     Since user  1  lives on floor  46  in the apartment with front door  50 , in this case it is on floor  46 , that swivelling around vertical axis V takes place towards door  50  in order to facilitate easy exiting. This swivelling movement is indicated by arrow B. On floor  44  in contrast, no swivelling takes place, because such swivelling is not provided in swivelling profile  64 . 1 . 
     LIST OF REFERENCE SIGNS 
     
         
           1  stair lift 
           2  user carrier (e.g. chair, wheelchair platform, stair walker) 
           4  authentication device 
           6  signal receiver 
           8  signal emitter 
           12  behavioral profile 
           14  rail drive 
           15  guiding rail 
           16  swivelling and tilting drive 
           17  lift body 
           18  lighting 
           20  speaker 
           22  user interface 
           24  control unit 
           26  authentication controller 
           28  database 
           30  operation controller 
           32  swivelling movement 
           34 ,  36  tilting movement 
           40  staircase 
           42  flight of the staircase 
           44  lower floor 
           46  upper floor 
           48  apartment front door on the lower floor 
           50  apartment front door on the upper floor 
           60  movement profile 
           62  stair lift speed profile 
           64  swivelling profile 
           66  tilting profile 
           70  surroundings profile 
           72  lighting brightness profile 
           74  lighting pattern 
           80  interaction profile 
           82  emergency details 
           84  voice signal profile 
         U user (or user profile) 
         R longitudinal axis of the guiding rail 
         H 1 , H 2  horizontal axes of the swivelling and tilting drive 
         V vertical axis of the swivelling and tilting drive