Patent Publication Number: US-9896303-B2

Title: Method for controlling elevator cars

Description:
FIELD 
     The present disclosure relates generally to elevator systems having a plurality of elevator cars and more specifically to a method of assigning an elevator car from a group of free elevator cars to service a priority call made to a priority floor. 
     BACKGROUND 
     Elevators are used in multi-floor buildings to transport passengers to various floors throughout the building. It is common for multi-floor buildings to have multiple elevator cars running to accommodate all calls in an efficient manner. Often, large buildings can have floors purposed differently including various combinations of office spaces and residence floors for example. Many times, passengers destined to different floors would prefer not to ride with each other. In this regard, some floors can be configured for restricted access. In some examples, offices may wish to permit access only to employees of the office and their guests. Similarly, residence floors may wish to permit access only to residents and their guests. Moreover, passengers do not like to stop at an excessive number of floors en-route to their destination. It is desirable to provide an elevator system having expedited service to predetermined floors while maintaining traffic flow with the remaining elevator cars at optimum efficiencies. 
     The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure. 
     SUMMARY 
     A method for controlling elevator cars of an elevator system according to one example of the present disclosure includes assigning free elevator cars of the elevator system to one of either general service or express priority service (EPS). A free elevator car is one that is not presently assigned to answer or respond to any particular type of service call, including a general service or EPS call, and is otherwise available to be called upon for service and may be assigned to any floor of the elevator system. Upon completion of a service call by either an EPS or general service assigned elevator car, if the elevator car is not immediately dispatched to respond to another service call, it becomes unassigned and a free car awaiting its next service call. In one aspect of the present disclosure, a destination dispatch controller, hereinafter “controller”, receives an EPS call. The EPS call can indicate a request for priority service from an EPS call originating location to an EPS call final destination. The controller can determine whether any active EPS car can service the EPS call. A particular elevator car can be an active EPS car when the particular car is carrying out EPS service. When a specific active EPS car can service the EPS call, the controller assigns the specific EPS car to the EPS call. Upon completion of the EPS call, if there are no other EPS or general service calls to service, the controller resets the status of the specific EPS car so that it is again designated as a free car. Any service call received by the controller that is not an EPS call is considered to be a general service call. 
     According to additional features, the controller can determine an estimated time of arrival (ETA) for each active EPS car for the EPS call. The ETA can comprise an estimated time required for an active EPS car to travel from a current location to the EPS call originating location. The controller can compare the ETA for each active EPS car to an ETA threshold. When the determined ETA for an active given EPS car is within the ETA threshold, the controller can assign that active EPS car to service the EPS call. According to another example, the controller can determine an estimated time to destination (ETD) for each active EPS car for the EPS call. The ETD can comprise a sum of an estimated overall time required for an active EPS car to travel (i) from a current location to the EPS call originating location and (ii) from the EPS call originating location to the EPS call final destination. The controller can compare the ETD for each active EPS car to an ETD threshold. When the determined ETD for a given active EPS car is within the ETD threshold, the controller can assign that active EPS car to service the EPS call. 
     According to other features, when no active EPS car can service the EPS call, the controller can determine whether a number of active EPS cars is below a car count threshold. When the number of active EPS cars is below the car count threshold, the controller can assign an additional car to service the EPS call. When the number of active EPS cars is not below the car count threshold, the controller can assign a best available active EPS car to service the EPS call. 
     According to still additional features, the controller can receive a destination input corresponding to an EPS floor. The controller can authorize a security input to grant a user access to an EPS elevator that will take the user to the desired EPS floor. Authorizing the security input can comprise at least one of, receiving an authorized personal identification number, recognizing biometric data of an individual, and receiving data from an authorized identification card or personal mobile communication device. 
     According to additional features, the controller determines if a car has a community car status or an isolation car status. The community car status can comprise an ability to combine another EPS call with the particular elevator car. The isolation car status can indicate that the particular elevator car is precluded from being combined with another call. 
     A method for controlling elevator cars of an elevator system according to additional features of the present disclosure can include receiving an express priority service (EPS) call. The EPS call can indicate a request for priority service wherein priority service comprises an ability to conduct expedited service from an EPS call originating location to an EPS call final destination. The controller can determine whether any active EPS car can service the EPS call. A particular elevator car can be an active EPS car when the particular car is carrying out EPS service. The controller can authorize a security input. When a specific active EPS car can service the EPS call, the controller can assign the specific EPS car to the EPS call. Upon completion of the EPS call, if there are no other EPS or general service calls to service, the controller can reassign the specific EPS car to become a free car. 
     According to additional features, authorizing a security input to grant access to an EPS elevator car can include at least one of receiving an authorized personal identification number, recognizing biometric data of an individual, and receiving data from an authorized identification card or personal communication device. According to additional features, the controller can determine an estimated time of arrival (ETA) for each active EPS car for the EPS call. The ETA can comprise an estimated time required for an active EPS car to travel from a current location to the EPS call originating location. The controller can compare the ETA to an ETA threshold. When the determined ETA is within the ETA threshold, the controller can assign the EPS car to service the EPS call. According to other features, the controller can determine an estimated time to destination (ETD) for each active EPS car for the EPS call. The ETD can comprise a sum of an estimated overall time required for an active EPS car to travel (i) from a current location to the EPS call originating location and (ii) from the EPS call originating location to the EPS call final destination. The controller can compare the ETD to an ETD threshold. When the determined ETD is within the ETD threshold, the controller can assign the EPS car to service the EPS call. 
     According to additional features, when no active EPS car can service the EPS call, the controller can determine whether a number of active EPS cars is below a car count threshold. When the number of active EPS cars is below the car count threshold, the controller can assign an additional car to service the EPS call. When the number of active EPS cars is not below the car count threshold, the controller can assign a best available active EPS car to service the EPS call. 
     A method for controlling elevator cars of an elevator system according to another example of the present disclosure can include assigning free elevator cars of the elevator system to general service or to EPS service. In one embodiment, the controller can receive an EPS call. The EPS call can indicate a request for priority service. Priority service can comprise an ability to conduct expedited service. The controller can determine whether any active EPS car can service the EPS call. A particular elevator car can be an active EPS car when the particular car is carrying out EPS service. The controller can authorize a security input comprising one of a personal identification number, recognizing biometric data of an individual, and receiving data from an authorized identification car or personal mobile communication device. When a specific active EPS car can service the EPS call, control can assign the specific EPS car to the EPS call. Upon completion of the EPS call, if there are no other EPS or general service calls to service, the controller resets the status of the specific EPS car so that it is again designated as a free car. According to other features, the controller can determine an estimated time of arrival (ETA) for each active EPS car for the EPS call. The ETA can comprise an estimated time required for an active EPS car to travel from a current location to the EPS call originating location. Control can compare the determined ETA to an ETA threshold. When the determined ETA is within the ETA threshold, control can service the EPS call. In other features, the controller can determine an estimated time to destination (ETD) for each active EPS car for the EPS call. The ETD can comprise a sum of an estimated overall time required for an active EPS car to travel (i) from a current location to the EPS call originating location and (ii) from the EPS call originating location to the EPS call final destination. The controller can compare the determined ETD to an ETD threshold. When the determined ETD is within the ETD threshold, control can service the EPS call. The security input can comprise one of a community car status and an isolation car status. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein: 
         FIG. 1  is a schematic illustration of an exemplary elevator system having express priority floors assigned in accordance to one example of the present disclosure; 
         FIG. 2  is a schematic illustration of an exemplary elevator system having express priority floors assigned in accordance to another example of the present disclosure; 
         FIG. 3  is a schematic illustration of an exemplary elevator system having express priority floors assigned in accordance to yet another example of the present disclosure; 
         FIG. 4  is a schematic illustration of an exemplary elevator system having express priority floors assigned in accordance to still another example of the present disclosure; 
         FIG. 5  is a front view of an exemplary destination dispatch panel that displays in sequence a first screen that identifies express priority floors and a second screen that prompts a prospective passenger for a personal identification number; 
         FIG. 6  is a front view of an exemplary destination dispatch panel that displays a screen that identifies express priority floors and prompts a prospective passenger to scan an identification card; 
         FIG. 7  is a front view of an exemplary destination dispatch panel that displays a screen identifying express priority floors; and 
         FIGS. 8A and 8B  show an exemplary method for controlling elevator cars of the elevator system according to one example of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     With initial reference to  FIG. 1 , a schematic illustration of an elevator system constructed in accordance to one example of the present teachings is shown and generally identified at reference numeral  10 . The elevator system  10  generally includes a plurality of elevators  1 -N. According to the example shown, the elevator system  10  includes a plurality of elevator cars collectively identified at reference numeral  20  and individually identified at reference numerals  20 A,  20 B,  20 C,  20 D and  20 N. Each of the elevator cars  20  operates within a corresponding elevator shaft collectively identified at reference numeral  22 . As will be described herein, the elevator cars  20  of the elevator system  10  are configured to service a plurality of floors, collectively identified at reference numeral  30  and identified in the example shown as floors  1 - 15 . It will be appreciated that while 15 floors are shown, a different number of floors may be provided. In the configuration shown in  FIG. 1 , the floors  30  include a series of general call floors  32  (floors  1 - 10 ) and a series of express priority floors  34  (floors  11 - 15 ). The elevator system  10  further includes an elevator controller  40  that controls dispatching of the elevator cars  20 . 
       FIG. 2  is a schematic illustration of an elevator system  110  constructed in accordance to another example of the present teachings. The elevator system  110  generally includes a plurality of elevators  1 -N. According to the example shown, the elevator system  110  includes a plurality of elevator cars collectively identified at reference numeral  120  and individually identified at reference numerals  120 A,  120 B,  120 C,  120 D and  120 N. Each of the elevator cars  120  operates within a corresponding elevator shaft collectively identified at reference numeral  122 . As will be described herein, the elevator cars  120  of the elevator system  110  are configured to service a plurality of floors, collectively identified at reference numeral  130  and identified in the example shown as floors  1 - 15 . Again, the elevator system  110  may have another quantity of floors. In the configuration shown in  FIG. 2 , the floors  130  include a first series of general call floors  132 A (floors  1 - 5 ), a second series of general call floors  132 B (floors  11 - 15 ) and a series of express priority floors  134  (floors  6 - 10 ). The elevator system  110  further includes an elevator controller  140  that controls dispatching of the elevator cars  120 . 
       FIG. 3  is a schematic illustration of an elevator system  210  constructed in accordance to another example of the present teachings. The elevator system  210  generally includes a plurality of elevators  1 -N. According to the example shown, the elevator system  210  includes a plurality of elevator cars collectively identified at reference numeral  220  and individually identified at reference numerals  220 A,  220 B,  220 C,  220 D and  220 N. Each of the elevator cars  220  operates within a corresponding elevator shaft collectively identified at reference numeral  222 . As will be described herein, the elevator cars  220  of the elevator system  210  are configured to service a plurality of floors, collectively identified at reference numeral  230  and identified in the example shown as floors  1 - 15 . More or less than 15 floors may be used. In the configuration shown in  FIG. 3 , the floors  230  include a first series of general call floors  232 A (floors  3 - 9 ), a second series of general call floors  232 B (floors  11 - 15 ), a first series of express priority floors  234 A (floors  1 - 2 ) and a second express priority floor  234 B (floor  10 ). The elevator system  210  further includes an elevator controller  240  that controls dispatching of the elevator cars  220 . 
       FIG. 4  is a schematic illustration of an elevator system  310  constructed in accordance to another example of the present teachings. The elevator system  310  generally includes a plurality of elevators  1 -N. According to the example shown, the elevator system  310  includes a plurality of elevator cars collectively identified at reference numeral  320  and individually identified at reference numerals  320 A,  320 B,  320 C,  320 D and  320 N. Each of the elevator cars  320  operates within a corresponding elevator shaft collectively identified at reference numeral  322 . As will become appreciated herein, the elevator cars  320  of the elevator system  310  are configured to service a plurality of floors, collectively identified at reference numeral  330  and identified in the example shown as floors  1 - 15 . Again, more or less than 15 floors may be used. In the configuration shown in  FIG. 4 , the floors  330  include a first series of general call floors  332 A (floors  3 - 9 ), a second series of general call floors  332 B (floors  11 - 15 ), an express priority group  1 ,  334 A (floors  1 - 2 ) and an express priority group  2 ,  334 B (floor  10 ). The elevator system  310  further includes an elevator controller  340  that controls dispatching of the elevator cars  320 . 
     As described herein, the elevator cars  20 ,  120 ,  220  and  320  of the respective elevator systems  10 ,  110 ,  210  and  310  include “free cars”, “EPS cars” and “general service cars”. A free car is an elevator car that is not presently assigned to answer or respond to any particular type of service call, including a general service call or EPS call, and is otherwise available to be called upon for service and may be assigned to any floor of the elevator system. Upon completion of a service call by either an EPS assigned or general service assigned elevator car, if the elevator car does not immediately respond to another service call, it is reset so that it is again designated as a free car awaiting its next service call. An EPS car is an elevator car that is designated to provide a user express priority service to a specific floor, floor zone, one of a subset of identified floors, or tenant on a designated floor whereby the car transports passenger(s) to the designated floor or floors in the zone/group in an expedited manner. In the case of an individual floor, the car travels directly to the desired floor. In the case of a zone or group, the EPS car services just the floors in the zone or floor group. A general service car is an elevator car that services any call that is not an EPS call and otherwise does not provide users any specific express or priority service. 
     As will become appreciated from the following discussion, EPS designation can be assigned to (i) a location or (ii) a person. In this regard, when EPS designation is used for a location, EPS can be assigned to a floor, a zone or a floor group. An EPS zone or floor group can be multiple EPS floors, either grouped together or separated by other non-EPS floors. An EPS floor can only be serviced by an EPS car assigned to the specific EPS floor. An EPS zone can only be serviced by an EPS car assigned to the specific EPS zone. When EPS designation is used for a person or an individual, EPS can be assigned to an individual rider or tenants sharing floor space with non-EPS designated tenants (floors serviceable by either general cars or EPS cars). 
     The following discussion will be focused on the elevator system  110  ( FIG. 2 ). The present disclosure provides a method for controlling the elevator cars  120  of the elevator system  110 . It will be appreciated however that the methods discussed herein are also applicable to any of the other elevator systems  10 ,  210  and  310  described above. Further, it will be appreciated that the elevator systems  10 ,  110 ,  210  and  310  are merely exemplary. In this regard, the following methods may be applicable to any elevator system having general call floors and express priority floors configured in any manner. 
     In the present embodiment, general call floors can be serviced by general call elevator cars. Express priority floors can be serviced by express priority service (EPS) cars. In an alternate embodiment, express priority floors can be serviced by EPS cars and general call elevator cars. In yet other embodiments, general call elevator cars can service EPS floors only when EPS is inactive. EPS cars can be configured for expedited service to express priority floors. Expedited service can include non-stop service or service only to express priority floors. It will be appreciated that in some examples a single express priority floor may have multiple express priority designated tenants located thereon. In such a scenario, each express priority tenant can be treated as a unique express priority floor while still occupying a common floor. In alternate embodiments, a single express priority floor may also be included in multiple express priority zones or floor groups comprising one or more floors. 
     The controller  140  can be any suitable controller or computing device having one or more processors configured to execute at least a portion of the operations described herein. The methods disclosed herein for dispatching the elevator cars  120  incorporate EPS. For the example shown in  FIG. 2 , EPS is designated for operation on the express priority floors  134  (floors  6 - 10 ). In one configuration, when the destination dispatch controller  140  receives an EPS call, the controller  140  assigns an elevator car  120  to transport a passenger directly to the desired EPS floor of the express priority floors  134 . 
     As will become appreciated from the following discussion, the methods according to the present teachings can require all of the elevator cars  120  to be unassigned free cars when not servicing an elevator call. Unassigned free cars have the ability to be assigned to any floor  130  of the elevator system  110 . Upon receiving an EPS call, the controller  140  assigns an unassigned free car as an EPS car to service the EPS call. Once the EPS call is completed, the EPS car returns to an unassigned free car status. By selectively assigning an unassigned free car to an EPS car that performs the EPS call and returning that car back to unassigned free car status, traffic flow can be maintained at optimum efficiencies. In this regard, none of the elevator cars  120  are permanently assigned to any floor. Instead, the controller  140  selectively assigns a specific elevator car from the elevator cars  20  to perform general service calls and EPS calls according to various criteria explained herein. Any call received by the controller other than an EPS call is considered to be a general service call. 
     Turning now to  FIGS. 5-7 , various destination displays will be described. A destination display  410  can include a display screen  420  that can be configured as an input interface that displays a series of input options  422 . The destination display  410  can be provided in a lobby of a building that includes the elevator system  110 . In one configuration, the destination display  410  can be provided at a kiosk located in the lobby of the building. It will be appreciated that while various examples of input interfaces are disclosed herein, other configurations are contemplated. In this regard, while various embodiments of the input interface configuration for the destination displays are disclosed herein, such embodiments are not intended to limit the scope of the configuration of the input displays. Explained further, other configurations and user interfaces permitting input of information into the display and elevator system are contemplated without departing from the scope of the present disclosure. 
     The destination display  410  can communicate with the controller  140 . In the example shown, the input options  422  correspond to the floors  130  ( FIG. 2 ). The input options  422  include a first series of inputs  422 A that correspond to the first general call floors  132 A (floors  1 - 5 ), a second series of inputs  422 B that correspond to the second general call floors  132 B (floors  11 - 15 ) and a third input  422 C that corresponds to the express priority floors  134  (floors  6 - 10 ). In one example, the destination dispatch panel  410  can be a touch screen that initially displays a first screen  430 A. The touch screen receives a user input corresponding to the desired floor destination. In the example shown in  FIG. 5 , the express priority floors  134  are initially displayed only as “EPS” on the first screen  430 A. Once a user, such as a prospective passenger, touches the “EPS” portion of the touch screen, the display screen  420  displays a second screen  430 B. In the second screen  430 B, the express priority floors  134  (floors  6 - 10 ) are displayed as a fourth series of inputs  422 D. According to the example shown in  FIG. 5 , the second screen  430 B prompts a user to enter a security input  450 . The security input  450  in  FIG. 5  requires a pin number to be entered. Once the controller  140  authorizes the security input  450 , an EPS car is assigned to the EPS call. 
       FIG. 6  illustrates another example wherein similar features described above in relation to  FIG. 5  are identified by reference numerals increased by 100. A destination display  510  configured according to another example of the present disclosure and shown in  FIG. 6  can include a display screen  520  that can be configured to display a series of input options  522 . The destination display  510  can further include a sensor  524  that is configured to sense a security device or input  545  such as an identification card in close proximity, a PIN, biometric data, or a mobile device. In one configuration, the identification card can include a radio frequency identification (RFID) tag and the sensor  524  can be an RFID reader. In other examples, the sensor  524  can be a magnetic reader that is configured to slidably receive an identification card having a magnetic strip. Other security devices are contemplated. In the example shown, the input options  522  correspond to the floors  130  ( FIG. 2 ). The input options  522  include a first series of inputs  522 A that correspond to the first general call floors  132 A (floors  1 - 5 ), a second series of inputs  522 B that correspond to the second general call floors  132 B (floors  11 - 15 ) and a third input  522 C that corresponds to the express priority floors  134  (floors  6 - 10 ). In one example, the destination display  510  can be a touch screen that initially displays a first screen  530 A ( FIG. 6 ). 
     The touch screen receives a user input corresponding to the desired floor destination. In the example shown in  FIG. 6 , the express priority floors  134  are initially displayed only as “Scan ID card for floors  6 - 10 ” on the first screen  530 A. If the user wishes to access floors  6 - 10 , they are required to provide authorization such as by placing an identification card in close proximity to the sensor  524 , or any of the other configurations described above. Once the security input is authorized by a third party security system, the controller  140 , or other similar authorization system, a second screen  530 B is displayed. If authorization is not satisfied, the second screen  530 B is not displayed. The second screen  530 B provides the user with options including a fourth series of inputs  522 D corresponding to the express priority floors  134  (floors  6 - 10 ). Once a user selects one of the inputs  522 D, the controller  140  assigns an EPS car to the EPS call. 
       FIG. 7  illustrates another example wherein similar features described above in relation to  FIG. 6  are identified by reference numerals increased by 40.  FIG. 7  illustrates an example where the express priority floors  134  are initially displayed together with a lock icon on the first screen  570 A. If a user wishes to access floors  6 - 10 , they are required to provide authorization such as by placing an identification card in close proximity to the sensor  564 , or any of the other configurations described above. Once the security input is authorized by a third party security system, the controller  140 , or other similar authorization system, a second screen  570 B is displayed. If authorization is not satisfied, the second screen  530 B is not displayed. The second screen  570 B provides the user with options including a fourth series of inputs  562 D corresponding to the express priority floors  134  (Floors  6 - 10 ). Once a user selects one of the inputs  522 D, the controller  140  assigns an EPS car to the EPS call. 
     In other examples, the destination displays  410 ,  510  and  550  can be configured to operate in conjunction with a mobile device such as a mobile phone. In this regard, the various screens  430 A,  430 B,  530 A,  530 B,  570 A and  570 B may be additionally or alternatively displayed for use on a prospective passenger&#39;s mobile device. In such examples, the controller  110  can additionally or alternatively receive inputs from a mobile device. 
     With reference now to  FIGS. 8A and 8B , a method for controlling elevator cars  130  of the elevator system  110  according to one example of the present disclosure is shown and generally identified at reference numeral  600 . At  602  the controller  140  assigns all cars as free cars. At  604 , the controller  140  determines whether an EPS call has been received. An EPS call indicates a request for priority service. If an EPS call has not been received, the controller  140  determines whether a general service call has been received at  612 . If not, the controller  140  loops to  602 . If a general service call has been received, the controller  140  determines whether general service is active at  616 . If general service is active, the controller  140  assigns a general service car to service the call at  620 . If general service is not active, the controller  140  assigns a free car to general service at  622 . At  624 , the general service call is serviced. At  626  the controller  140  determines whether all general service calls are complete. If not, the controller  140  loops to  620 . If all general service calls are complete, the car is reassigned to free (unassigned) status at  630 . 
     If an EPS call has been received at  604 , the controller  140  determines if EPS is active at  610  ( FIG. 8B ). If EPS is not active, the controller  140  activates EPS at  638 . The controller  140  then proceeds to  636 . If EPS is active, the controller  140  determines a timing requirement for each active EPS car at  636 . In one example, the timing requirement can be an estimated time of arrival (ETA). The ETA is an estimated time required for an active EPS car to travel from a current location to the EPS call originating location (or the present location of the prospective passenger). In another example, the timing requirement can be an estimated time to destination (ETD) for each active EPS car. The ETD is a sum of an estimated overall time required for an active EPS car to travel (i) from a current location to the EPS call originating location and (ii) from the EPS call originating location to the EPS call final destination. The EPS call final destination can be the requested destination selected by the prospective passenger. In yet another example, the timing requirement can be an estimated time from when elevator doors open to pick up the prospective passenger to the moment the prospective passenger arrives at the EPS call final destination. It will be appreciated that the timing requirements and thresholds may be determined and affected by other variables within the scope of the present disclosure. 
     In  640 , the controller  140  determines whether an active EPS car can service the EPS call. In one example, the controller  140  compares at least one of the determined ETA to an ETA threshold and the determined ETD to an ETD threshold for each active EPS car. When at least one of the ETA and ETD is within the respective ETA and ETD threshold for a specific car, the controller  140  assigns an EPS car to the EPS call at  642  and services the EPS call at  660  with the specific active EPS car. In other examples, the controller  140  can service the EPS call with a specific active EPS car if both of the ETA and ETD are within the respective ETA and ETD thresholds. 
     In one example, the controller  140  receives a destination input corresponding to an EPS floor and authorizes a security input to grant access to an EPS elevator car in  640 . The security input can include authorizing a personal identification number (see also  FIGS. 5-7 ), recognizing biometric data of an individual and receiving data from an authorized identification card, personal communication device or any other security protocol. Biometric data includes, but is not limited to, a fingerprint scan, a retinal scan, voice recognition, facial recognition and other characteristics associated with the prospective user. 
     In some examples, the controller  140  can also determine if a car has a community car preference or an isolation car preference. A community car preference can comprise the ability to combine elevator calls. An isolation car preference can comprise an indication that a particular elevator car is precluded from being combined with other elevator calls. In this regard, an EPS call can be serviced with any active elevator car having a community car preference and not an isolation car preference. In one configuration, all EPS calls may be community calls. In other examples, all EPS calls may be isolation calls. In still other configurations, calls may be split between community calls and isolation calls. The community car or isolation car preference may be (but is not required to be) accessed at the time the security authorization is determined. The community and isolation car preference can be assigned to a user, a floor, a zone or a specific tenant. The preference can be established by security credentials or determined by the controller and can be temporary or permanent. The preference can be stored in a user profile on the elevator system, stored on a security identification card or other security access key fob. In one example, a certain individual, such as a VIP may have an isolation preference in their profile that allows that person to ride alone. 
     When the community car preference is assigned to an EPS floor, zone or floor group, all calls to the same floor or zone are combined so all riders occupy the same EPS car. When the isolation car preference is assigned to an EPS floor or zone, no other calls can be assigned to the EPS car. When the community car preference is assigned to individual riders designated with EPS access, all EPS calls to a particular floor can be combined into that EPS car. When the community car preference is assigned to individual riders, all calls (including general service calls) going to an EPS passenger&#39;s selected floor are combined into that passenger&#39;s EPS car. When the isolation car preference is assigned to an individual rider designated with EPS access, no other calls can be assigned to that rider&#39;s EPS car. When the community car preference is assigned to tenants sharing floor space with non-EPS designated tenants, all calls (including general service calls) to the tenant&#39;s floor are combined into the same EPS car going to the tenant. When the isolation car preference is assigned by a passenger, the passenger rides alone to the tenant floor on the EPS car. When the isolation car preference is assigned by a tenant, all EPS calls to the same tenant floor are combined in the same EPS car. General calls to the same floor as an EPS tenant are serviced by a general car rather than by an EPS car. 
     It will be appreciated that in some configurations, the controller  140  may not require a security input. In this regard, the elevator system  110  may be configured to assign an EPS car without requiring a prospective passenger to provide a security input. A general call to a specific EPS floor may be assigned to an EPS elevator as long as the EPS car already had an EPS call to the specific EPS floor assigned to it. Such a scenario can be useful when an EPS car has been assigned to service an EPS call for a first passenger, and before the EPS car arrives to pick up the first passenger, a second prospective passenger desires to travel to the same floor as the first passenger. The controller will not require a security input from the second prospective passenger and will instead assign the second prospective passenger to the EPS car already assigned to service the first passenger. 
     If the controller  140  determines that an active EPS car can service the EPS call in  640 , an EPS car is assigned to the EPS call in  642  and the EPS call is serviced in  660 . If the controller  140  determines that an active EPS car cannot service the EPS call, the controller  140  determines whether the number of active EPS cars is below a car count threshold at  646 . The car count threshold can be set at any value such as 2 cars or 3 cars. Additionally or alternatively the car count threshold can be a percent of the total amount of active cars such as 25% for example. If the controller  140  determines that the number of active EPS cars is below a threshold, an additional car is assigned to EPS service in  650  and the controller  140  loops to  660  to service the EPS call. If the controller  140  determines that the number of active EPS cars is not below a threshold, the best active car is selected in  652 . In one example, the best active car can be selected from the active EPS cars such as by comparing the respective ETA&#39;s and/or ETD&#39;s for all active EPS cars and selecting the best one. In other examples, the best active car can be selected from the general service cars. According to still another example, the controller  140  can forgo  652  and simply loop to  636  and wait until an active EPS car can service the EPS call within at least one of the ETA and ETD thresholds. 
     The controller  140  determines whether all EPS service calls have been completed in  662 . If all of the EPS service calls have not been completed, the controller  140  loops to  636 . If the controller  140  determines that all EPS calls have been completed, the EPS car is reassigned to free car status at  630  ( FIG. 8A ). Explained differently, the EPS car is unassigned and becomes a free car. 
     The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. In this regard, the ordering of method steps is not necessarily fixed, but may be capable of being modified without departing from the instant teachings. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.