Abstract:
An elevator system utilizes a destination entry control technique and delays indicating which car is assigned to a request to allow an individual to arrive near an elevator lobby. An elevator group assignment is made responsive to a destination request. An indication regarding the group assignment is provided to a passenger within a first time from the receipt of the request. A second indication regarding a car assigned to carry that passenger to the desired destination is provided at a second, later time from the request. Separating out the group assignment indication and the car assignment indication is accomplished in one example by providing separate interfaces at different locations within a building.

Description:
FIELD OF THE INVENTION 
   This invention generally relates to elevator systems. More particularly, this invention relates to assigning cars in a destination entry system. 
   DESCRIPTION OF THE RELATED ART 
   Elevator systems are in widespread use throughout the world. Various system configurations and strategies are known for controlling passenger traffic and efficiently operating an elevator system. 
   Traditionally, hall call buttons allowed passengers to place a call to go up or down within a building and then to select a destination floor from a car operating panel located within an elevator car. While such arrangements are useful for many situations, larger buildings with more traffic volume have been shown to benefit from other control techniques. One example technique is known as destination entry. 
   In a destination entry system a passenger provides an indication of a desired destination outside of an elevator car. Most destination entry systems include destination entry kiosks within an elevator boarding area. A controller uses known techniques for assigning that passenger&#39;s travel to a particular elevator car. Various techniques for conveying the car assignment information and directing passengers to the appropriate car are known. 
   One situation where known destination entry systems have shortcomings is a situation where an individual places a destination request a significant distance from an assigned elevator car or a significant amount of time prior to the individual&#39;s arrival near the car. Known systems provide immediate feedback regarding a car assignment responsive to the passenger&#39;s request. Under such circumstances, an individual typically is required to remember the assigned elevator group and the assigned car within that group in order to reach their desired destination. Additionally, there can be a relatively large range of travel time for individual passengers to get to the appropriate elevator group. Therefore, timing the arrival of the assigned car to meet a passenger can be difficult. 
   A further complexity is introduced when considering that most destination entry systems include control algorithms that are designed to effectively look ahead a certain amount of time but they are not designed to assign cars more than a minute in advance of when the assignment is actually needed. Therefore, known elevator dispatchers including destination entry systems are not adequately equipped to provide feedback to passengers who will not actually board an elevator car for at least 45 seconds after placing a request to be carried to a particular destination. 
   This invention provides an improved arrangement that enhances the ability for directing passengers to particular elevator cars even when the passenger will not arrive in the vicinity of the car for some time after the elevator system controller receives the request regarding their intended destination. 
   SUMMARY OF THE INVENTION 
   An exemplary disclosed system for controlling elevator traffic includes a controller that automatically assigns an elevator car within a selected elevator group to carry a passenger to a desired destination responsive to a request to travel to the desired destination. The controller provides an indication of the assigned car after a selected time has expired since receipt of the request. 
   In one example, the controller provides a first indication of the selected elevator group to the passenger within a first time from the request. The controller provides a second indication of an assigned elevator car to the passenger at a second, later time from the request. 
   By providing an indication of the elevator group in advance of providing an indication of the assigned car, an individual passenger need only recall the elevator group to which their request has been assigned. Later, such as upon arrival in the vicinity of the elevator group, for example, the second indication notifies the passenger of the particular car that will travel to the desired destination. This arrangement facilitates allowing an individual to place a destination request well in advance of arriving in the vicinity of the actual elevator car that will carry them to their intended destination. The example arrangement also allows a controller to take into account various elevator system conditions occurring between receipt of a request and a car assignment to make a more efficient car assignment. 
   A disclosed method of directing elevator passengers responsive to requests to travel to destinations includes providing selected elevator group indication to at least one passenger within a first time from the request. An indication of the assigned elevator car is provided to the passenger at a second, later time after the request. 
   The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description. The drawing that accompanies the detailed description can be briefly described as follows. 

   
     BRIEF DESCRIPTION OF THE DRAWING 
       FIG. 1  schematically shows an example elevator system designed according to an embodiment of this invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1  schematically shows an elevator system  20  within a building  22 . A plurality of access points  24  and  26  (i.e., doorways) allow individuals to enter a portion of the building space. The access points  24  and  26  are located remotely and, in this example, a considerable, fixed distance from a plurality of elevator groups  30 ,  32 ,  34 ,  36 ,  38  and  40 . 
   The example elevator system  20  includes controlling elevator car movement and directing passenger traffic using destination entry techniques. The example system is particularly well suited to directing passengers to their assigned car even when there is a considerable amount of time between when the passenger&#39;s destination request is received by the system and when the passenger arrives in the vicinity of an appropriate elevator car. 
   Considering the elevator group  40  as an example, a plurality of cars A-F are included within the group. Known techniques for assigning particular cars to particular floor destinations are used by a group controller  42 . The group controller  42  communicates with a main control  50  for determining how many calls are assigned to that group. In one example, the main control  50  makes the car assignments. In another example, the group controllers make car assignments within their respective groups 
   It should be noted that the various controllers schematically shown in  FIG. 1  are divided up only for discussion purposes. In one example, a single controller may include a plurality of hardware or software modules that perform the various functions of the controllers schematically shown in  FIG. 1 . Those skilled in the art who have the benefit of this description will realize how to integrate or separate control components and functions to meet the needs of their particular situation. 
   In the example of  FIG. 1 , the main control  50  receives destination requests from individuals entering the building  22  at the access points  24  or  26 . In the illustrated example, destination entry devices  52 ,  54 ,  56  and  58  are arranged to receive the passenger destination requests. In one example, the destination entry devices  52 - 58  include card readers that obtain information from cards carried by individuals and which include an indication of the identity of that individual. For example, one individual entering the building  22  may be required to report to a particular floor to begin work that day. The information on their destination entry card would be useful for determining the appropriate floor level to which they must report. In one example, a database accessible by the main control  50  includes destination information for each access card or each identity indication. In another example, the access card provides a signal that includes a direct indication of the destination request. 
   One advantage to the disclosed arrangement is that the destination entry devices  52 - 58  can be located immediately adjacent an access point to a building. They also may be integrated into a building security system which requires interaction with or operation of a particular device to gain access to the building space. In one example, the same input device that allows an individual to gain access to the building obtains the destination request in an automated fashion so that the individual need not make a separate request for purposes of placing an elevator call. Such an arrangement provides seamless integration of building access functions like security and elevator travel and maximizes traffic flow in the building. 
   The control  50  receives the destination requests and determines which of the elevator groups  30 - 40  will be assigned to carry that individual to the desired destination. A plurality of first interfaces  62 ,  64 ,  66  and  68  are provided in the illustrated example for providing an indication regarding the elevator group to which an individual&#39;s request has been assigned. In this example, the first interfaces  62 - 68  provide essentially immediate feedback to passengers regarding the elevator group that will service them for purposes of eventually arriving at their desired destination. 
   In one example, the first interfaces  62 - 68  include display screens for providing a visual indication to passengers regarding the assigned elevator group. In another example, the interfaces  62 - 68  provide an audible elevator group indication. The first interfaces  62 - 68  advantageously can be located near the access points  24  and  26  to the building. In one example, the interfaces  62 - 68  are placed near the entry devices  52 - 58  to provide feedback when passing through such devices. This allows an individual to obtain information regarding the elevator group assigned to their destination request upon entry into the building  22 , for example. 
   In another example, no group indication is necessary and the interfaces  62 - 68  may not be needed. 
   As the individual passengers may take some time to arrive at the appropriate elevator group, the corresponding group controller  42  provides a separate indication of their assigned car approximately when the individual arrives or is expected to arrive in the vicinity of the appropriate elevator group. In the illustrated example, the second interfaces  70 ,  72  and  74  are provided near the respective elevator groups. The second interfaces  70 - 74  provide an indication to passengers regarding the car assigned to carry them to their desired destination. In one example, the second interfaces  70 - 74  provide a visual indication of cars and corresponding floors to which they will travel. Another example includes second interfaces that provide an audible indication of car assignments. 
   The main control  50  in one example controls the timing of providing the group assignment and the car assignments to the passengers. In another example, the corresponding group controller  42  controls the timing of the car assignment. The indication regarding the assigned group is provided within a first time from receiving the request. The indication regarding the assigned car is provided at a second, later time after receiving the request. Providing the group indication and the car indication at separate times facilitates allowing the individual to arrive at the appropriate elevator car location without requiring them to recall the group and car assignments over time. 
   In one example, the control  50  times the provision of the indication regarding the assigned car with an expected, average arrival time of a passenger at the elevator groups based on a distance from the location where the destination requests are received. In another example, the control  50  customizes the display of the assigned car indications based on an estimated or actual arrival of a passenger near the appropriate elevator group. 
   The example of  FIG. 1  includes a plurality of sensors  80  positioned near the elevator groups for detecting the presence of passengers who place a particular destination request. In one example, a so-called smart card provides a wirelessly transmitted radio frequency signal that at least identifies the passenger in some manner. The controller uses a database to determine a destination request corresponding to the identity information. In another example, the signal from the card contains an actual destination request indication. In either example, the sensors  80  detect signals automatically transmitted by such cards and the control  50  or the group controller  42  determines when the individual carrying each card is within the vicinity of the assigned elevator group. At that time, the control  50  or group controller  42  determines that it is appropriate to display the assigned car indication or otherwise to provide it in a manner to direct that passenger to the assigned car. 
   In another example, sensors  80  are located within the building space in a manner to allow tracking an individual&#39;s approach to the appropriate elevator group. Such an arrangement provides additional options for timing when to provide the indications of the car assignment. 
   In one example system, the control  50  and any of the group controllers  42  can determine the assigned group and assigned car simultaneously responsive to the destination request. In one example, the group assignment is made at some time before making the actual car assignment. In this example, the appropriate controller has time to consider what has occurred since the destination request was placed before making the car assignment. This allows for more efficient car assignments because the elevator traffic between the time the request was placed and the time of estimated or actual arrival of the passenger near the elevator groups may impact the best car selection, for example. Making the car assignment at a later time from making the group assignment allows for such an example system to further maximize the system efficiency and passenger service. 
   Another advantage to the disclosed examples are that they can be used in parallel with one or more known destination entry systems. 
   The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this invention. The scope of legal protection given to this invention can only be determined by studying the following claims.