Patent Publication Number: US-10787340-B2

Title: Sensor and drive motor learn run for elevator systems

Description:
PRIORITY 
     This application claims priority to Indian Provisional Patent Application No. 201611020113, filed Jun. 13, 2017, 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 subject matter disclosed herein generally relates to the field of elevators, and more particularly to a sensor and drive motor segment location determination within an elevator system. 
     Ropeless elevator systems, also referred to as self-propelled elevator systems, are useful in certain applications (e.g., high rise buildings) where the mass of the ropes for a roped system is prohibitive and there is a desire for multiple elevator cars to travel in a single hoistway, elevator shaft, or lane. There exist conceptually ropeless elevator systems in which a first lane is designated for upward traveling elevator cars and a second lane is designated for downward traveling elevator cars. A transfer station at each end of the lane is used to move cars horizontally between the first lane and second lane. Multi-car ropeless elevator systems can require a large number of sensors and drive motor segments to operate, which often complicates and lengthens an installation process. 
     BRIEF SUMMARY 
     According to one embodiment, a method of operating an elevator system for a learn run sequence is provided. The method including the steps of moving, using a linear propulsion system, an elevator car through a lane of an elevator shaft at a selected velocity. The linear propulsion system including: a first part mounted in the lane of the elevator shaft; and a second part mounted to the elevator car, the second part being configured to co-act with the first part to impart movement to the elevator car. The method also including the steps of: detecting, using a sensor system, the location of the elevator car when it moves through the lane. The sensor system including; a plurality of sensed elements disposed on the elevator car; and a plurality of car state sensors disposed within the lane, the plurality of car state sensors being configured to detect the sensed element when the elevator car is in proximity to the respective car state sensor. The method further includes the steps of: controlling, using a control system, the elevator car, the control system being in operable communication with the elevator car, the linear propulsion system, and the sensor system; and determining, using the control system, a location of each of the car state sensors relative to each other within the lane in response to at least one of a travel time of the elevator car, a velocity of the elevator car, a position of the elevator car, and a height of the elevator car. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the method may include that the first part includes one or more motor segments and one or more associated drives; and the second part includes one or more permanent magnets. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the method may include determining, using the control system, at least one of the location, the length, and the phasing of each of the one or more motor segments in response to a back electromotive force of the motor segments. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the method may include configuring each of the drives in response to the location of the motor segment. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the method may include that the elevator car is a first elevator car. The system further includes a second elevator car disposed in the same lane of the elevator shaft as the first elevator car. The plurality of car state sensors are configured to determine a location of each the first elevator car and the second elevator car. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the method may include that the plurality of car state sensors define a plurality of first car state sensors disposed with a first lane and the elevator car is a first elevator car in the first lane. The system further including: a second elevator car disposed in a second lane of the elevator shaft; and a plurality of second car state sensors disposed within the second lane configured to determine a location of the second elevator car. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the method may include that the elevator system is a multicar, ropeless elevator system. 
     According to another embodiment, an elevator system is provided. The system including: a processor; a memory including computer-executable instructions that, when executed by the processor, cause the processor to perform operations. The operations including the steps of: moving, using a linear propulsion system, an elevator car through a lane of an elevator shaft at a selected velocity. The linear propulsion system including: a first part mounted in the lane of the elevator shaft; and a second part mounted to the elevator car, the second part being configured to co-act with the first part to impart movement to the elevator car. The operations also include the step of detecting, using a sensor system, the location of the elevator car when it moves through the lane. The sensor system including; a plurality of sensed elements disposed on the elevator car; and a plurality of car state sensors disposed within the lane, the plurality of car state sensors being configured to detect the sensed element when the elevator car is in proximity to the respective car state sensor. The operations further including the steps of: controlling, using a control system, the elevator car, the control system being in operable communication with the elevator car, the linear propulsion system, and the sensor system; and determining, using the control system, a location of each of the car state sensors relative to each other within the lane in response to at least one of a travel time of the elevator car, a velocity of the elevator car, a position of the elevator car, and a height of the elevator car. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the system may include that the first part includes one or more motor segments and one or more associated drives; and the second part includes one or more permanent magnets. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the system may include that the operations further include: determining, using the control system, at least one of the location, the length, and the phasing of each of the one or more motor segments in response to a back electromotive force of the motor segments. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the system may include that the operations further include: configuring each of the drives in response to the location of the motor segment. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the system may include that the elevator car is a first elevator car, the system further includes: a second elevator car disposed in the same lane of the elevator shaft as the first elevator car, the plurality of car state sensors are configured to determine a location of each the first elevator car and the second elevator car. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the system may include that the plurality of car state sensors define a plurality of first car state sensors disposed with a first lane and the elevator car is a first elevator car in the first lane, the system further includes: a second elevator car disposed in a second lane of the elevator shaft; and a plurality of second car state sensors disposed within the second lane configured to determine a location of the second elevator car. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the system may include that the elevator system is a multicar, ropeless elevator system. 
     According to another embodiment, a computer program product tangibly embodied on a computer readable medium is provided. The computer program product including instructions that, when executed by a processor, cause the processor to perform operations. The operations including: moving, using a linear propulsion system, an elevator car through a lane of an elevator shaft at a selected velocity. The linear propulsion system including: a first part mounted in the lane of the elevator shaft; and a second part mounted to the elevator car, the second part being configured to co-act with the first part to impart movement to the elevator car. The operations also include: detecting, using a sensor system, the location of the elevator car when it moves through the lane. The sensor system including: a plurality of sensed elements disposed on the elevator car; and a plurality of car state sensors disposed within the lane. The plurality of car state sensors being configured to detect the sensed element when the elevator car is in proximity to the respective car state sensor. The operations further include: controlling, using a control system, the elevator car, the control system being in operable communication with the elevator car, the linear propulsion system, and the sensor system; and determining, using the control system, a location of each of the car state sensors relative to each other within the lane in response to a travel time of the elevator car, a velocity of the elevator car, a position of the elevator car, and a height of the elevator car. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the computer program may include that the first part includes one or more motor segments and one or more associated drives; and the second part includes one or more permanent magnets. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the computer program may include that the operations further include: determining, using the control system, at least one of the location, the length, and the phasing of each of the one or more motor segments in response to a back electromotive force of the motor segments. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the computer program may include that the operations further include: configuring each of the drives in response to the location of the motor segment. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the computer program may include that the elevator car is a first elevator car, the system further including a second elevator car disposed in the same lane of the elevator shaft as the first elevator car, the plurality of car state sensors are configured to determine a location of each the first elevator car and the second elevator car. 
     In addition to one or more of the features described above, or as an alternative, further embodiments of the computer program may include that the plurality of car state sensors define a plurality of first car state sensors disposed with a first lane and the elevator car is a first elevator car in the first lane. The system further including: a second elevator car disposed in a second lane of the elevator shaft; and a plurality of second car state sensors disposed within the second lane configured to determine a location of the second elevator car. 
     Technical effects of embodiments of the present disclosure include a learn run sequence for determining the location of sensors and drive motor segment determination within elevator system. Further technical embodiments include utilizing a learn run sequence for configuring the drive control system within an elevator system. 
     The foregoing features and elements may be combined in various combinations without exclusivity, unless expressly indicated otherwise. These features and elements as well as the operation thereof will become more apparent in light of the following description and the accompanying drawings. It should be understood, however, that the following description and drawings are intended to be illustrative and explanatory in nature and non-limiting. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other features, and advantages of the disclosure are apparent from the following detailed description taken in conjunction with the accompanying drawings in which like elements are numbered alike in the several FIGURES: 
         FIG. 1  illustrates a schematic view of a multicar elevator system, in accordance with an embodiment of the disclosure; 
         FIG. 2  illustrates an enlarged schematic view of a single elevator car within the multicar elevator system of  FIG. 1 , in accordance with an embodiment of the disclosure; 
         FIG. 3  illustrates an enlarge schematic view of a the single elevator car of  FIG. 2  having a sensing system, in accordance with an embodiment of the disclosure; 
         FIG. 4  is a flow diagram illustrating a method of operating the multi-car elevator system of  FIG. 2-3  for a learn run sequence, according to an embodiment of the present disclosure; 
         FIG. 5  illustrates an incremental sensor detection for the learn run sequence of  FIG. 4 , according to an embodiment of the present disclosure; 
         FIG. 6  illustrates an incremental sensor detection for the learn run sequence of  FIG. 4 , according to an embodiment of the present disclosure; and 
         FIG. 7  is a graph displacing a back electromotive force versus an elevator car location for various drive motor segments of the elevator system of  FIGS. 1-3 , according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  depicts a multicar, ropeless elevator system  100  that may be employed with embodiments of the present disclosure. The ropeless elevator system  100  includes an elevator shaft  111  having a plurality of lanes  113 ,  115  and  117 . While three lanes  113 ,  115 ,  117  are shown in  FIG. 1 , it is understood that various embodiments of the present disclosure and various configurations of a multicar, ropeless elevator system may include any number of lanes, either more or fewer than the three lanes shown in  FIG. 1 . In each lane  113 ,  115 ,  117 , multiple elevator cars  114  can travel in one direction, i.e., up as shown by arrow  184  or down as shown by arrow  182 , or multiple cars within a single lane may be configured to move in opposite directions, as shown by arrow  186 . For example, in  FIG. 1  elevator cars  114  in lanes  113  and  115  travel up in the direction of arrow  184  and elevator cars  114  in lane  117  travel down in the direction of arrow  182 . Further, as shown in  FIG. 1 , one or more elevator cars  114  may travel in a single lane  113 ,  115 , and  117 . 
     As shown, above the top accessible floor of the building is an upper transfer station  130  configured to impart horizontal motion to the elevator cars  114  to move the elevator cars  114  between lanes  113 ,  115 , and  117 . It is understood that upper transfer station  130  may be located at the top floor, rather than above the top floor. Similarly, below the first floor of the building is a lower transfer station  132  configured to impart horizontal motion to the elevator cars  114  to move the elevator cars  114  between lanes  113 ,  115 , and  117 . It is understood that lower transfer station  132  may be located on the first floor, rather than below the first floor. Although not shown in  FIG. 1 , one or more intermediate transfer stations may be configured between the lower transfer station  132  and the upper transfer station  130 . Intermediate transfer stations are similar to the upper transfer station  130  and lower transfer station  132  and are configured to impart horizontal motion to the elevator cars  114  at the respective transfer station, thus enabling transfer from one lane to another lane at an intermediary point within the elevator shaft  111 . Further, although not shown in  FIG. 1 , the elevator cars  114  are configured to stop at a plurality of floors  140  to allow ingress to and egress from the elevator cars  114 . 
     Elevator cars  114  are propelled within lanes  113 ,  115 ,  117  using a propulsion system such as a linear, permanent magnet motor system having a primary, fixed portion, or first part  116 , and a secondary, moving portion, or second part  118 . The first part  116  is a fixed part because it is mounted to a portion of the lane, and the second part  118  is a moving part because it is mounted on the elevator car  114  that is movable within the lane. 
     The first part  116  includes windings or coils mounted on a structural member  119 , and may be mounted at one or both sides of the lanes  113 ,  115 , and  117 , relative to the elevator cars  114 . Specifically, first parts  116  will be located within the lanes  113 ,  115 ,  117 , on walls or sides that do not include elevator doors. 
     The second part  118  includes permanent magnets mounted to one or both sides of cars  114 , i.e., on the same sides as the first part  116 . The second part  118  engages with the first part  116  to support and drive the elevators cars  114  within the lanes  113 ,  115 ,  117 . First part  116  is supplied with drive signals from one or more drive units  120  to control movement of elevator cars  114  in their respective lanes through the linear, permanent magnet motor system. The second part  118  operatively connects with and electromagnetically operates with the first part  116  to be driven by the signals and electrical power. The driven second part  118  enables the elevator cars  114  to move along the first part  116  and thus move within a lane  113 ,  115 , and  117 . 
     Those of skill in the art will appreciate that the first part  116  and second part  118  are not limited to this example. In alternative embodiments, the first part  116  may be configured as permanent magnets, and the second part  118  may be configured as windings or coils. Further, those of skill in the art will appreciate that other types of propulsion may be used without departing from the scope of the present disclosure. For example, other linear motors may be utilized including any combination of synchronous, induction, homopolar, and piezo electric motors. 
     The first part  116 , as shown in  FIG. 1 , is formed from a plurality of motor segments  122  (Seen in  FIG. 2 ), with each segment associated with a drive unit  120 . Although not shown, the central lane  115  of  FIG. 1  also includes a drive unit for each segment of the first part  116  that is within the lane  115 . Those of skill in the art will appreciate that although a drive unit  120  is provided for each motor segment  122  (Seen in  FIG. 2 ) of the system (one-to-one) other configurations may be used without departing from the scope of the present disclosure. Further, those of skill in the art will appreciate that other types of propulsion may be employed without departing from the scope of the present disclosure. For example, a magnetic screw may be used for a propulsion system of elevator cars. Thus, the described and shown propulsion system of this disclosure is merely provided for explanatory purposes, and is not intended to be limiting. 
     Turning now to  FIG. 2 , a view of an elevator system  110  including an elevator car  114  that travels in lane  113  is shown. Elevator car  114  is guided by one or more guide rails  124  extending along the length of lane  113 , where the guide rails  124  may be affixed to a structural member  119 . For ease of illustration, the view of  FIG. 2  only depicts a single guide rail  124 ; however, there may be any number of guide rails positioned within the lane  113  and may, for example, be positioned on opposite sides of the elevator car  114 . Elevator system  110  employs a linear propulsion system as described above, where a first part  116  includes multiple motor segments  122   a ,  122   b ,  122   c ,  122   d  each with one or more coils  126  (i.e., phase windings). The first part  116  may be mounted to guide rail  124 , incorporated into the guide rail  124 , or may be located apart from guide rail  124  on structural member  119 . The first part  116  serves as a stator of a permanent magnet synchronous linear motor to impart force to elevator car  114 . The second part  118 , as shown in  FIG. 2 , is mounted to the elevator car  114  and includes an array of one or more permanent magnets  128  to form a second portion of the linear propulsion system of the ropeless elevator system. Coils  126  of motor segments  122   a ,  122   b ,  122   c ,  122   d  may be arranged in one or more phases, as is known in the electric motor art, e.g., three, six, etc. One or more first parts  116  may be mounted in the lane  113 , to co-act with permanent magnets  128  mounted to elevator car  114 . Although only a single side of elevator car  114  is shown with permanent magnets  128  the example of  FIG. 2 , the permanent magnets  128  may be positioned on two or more sides of elevator car  114 . Alternate embodiments may use a single first part  116 /second part  118  configuration, or multiple first part  116 /second part  118  configurations. 
     In the example of  FIG. 2 , there are four motor segments  122   a ,  122   b ,  122   c ,  122   d  depicted. Each of the motor segments  122   a ,  122   b ,  122   c ,  122   d  has a corresponding or associated drive  120   a ,  120   b ,  120   c ,  120   d . A system controller  125  provides command signals to the drive  120   a ,  120   b ,  120   c ,  120   d , which are used to calculate the drive signals sent to the motor segments  122   a ,  122   b ,  122   c ,  122   d  via drives  120   a ,  120   b ,  120   c ,  120   d  to control motion of the elevator car  114 . The system controller  125  may be implemented using a microprocessor executing a computer program stored on a storage medium to perform the operations described herein. Alternatively, the system controller  125  may be implemented in hardware (e.g., ASIC, FPGA) or in a combination of hardware/software. The system controller  125  may also be part of an elevator control system. The system controller  125  may include power circuitry (e.g., an inverter or drive) to power the first part  116 . Although a single system controller  125  is depicted, it will be understood by those of ordinary skill in the art that a plurality of system controllers may be used. For example, a single system controller may be provided to control the operation of a group of motor segments over a relatively short distance, and in some embodiments a single system controller may be provided for each drive unit or group of drive units, with the system controllers in communication with each other. 
     In some embodiments, as shown in  FIG. 2 , the elevator car  114  includes an on-board controller  156  with one or more transceivers  138  and a processor, or CPU,  134 . The on-board controller  156  and the system controller  125  collectively form a control system where computational processing may be shifted between the on-board controller  156  and the system controller  125 . 
     The controller system may include at least one processor and at least one associated memory comprising computer-executable instructions that, when executed by the processor, cause the processor to perform various operations. The processor may be but is not limited to a single-processor or multi-processor system of any of a wide array of possible architectures, including field programmable gate array (FPGA), central processing unit (CPU), application specific integrated circuits (ASIC), digital signal processor (DSP) or graphics processing unit (GPU) hardware arranged homogenously or heterogeneously. The memory may be a storage device such as, for example, a random access memory (RAM), read only memory (ROM), or other electronic, optical, magnetic or any other computer readable medium. 
     In some embodiments, the processor  134  of on-board controller  156  is configured to monitor one or more sensors and to communicate with one or more system controllers  125  via the transceivers  138 . In some embodiments, to ensure reliable communication, elevator car  114  may include at least two transceivers  138  configured for redundancy of communication. The transceivers  138  can be set to operate at different frequencies, or communication channels, to minimize interference and to provide full duplex communication between the elevator car  114  and the one or more system controllers  125 . In the example of  FIG. 2 , the on-board controller  156  may interface with a load sensor  152  to detect an elevator load on a brake  136 . The brake  136  may engage with the structural member  119 , a guide rail  124 , or other structure in the lane  113 . Although the example of  FIG. 2  depicts only a single load sensor  152  and brake  136 , elevator car  114  can include multiple load sensors  152  and brakes  136 . 
     In an embodiment, the ropeless elevator system  100  may include a configuration system  170  operatively connected to the control system (controller  125  and on-board controller  156 ). The configuration system  170  may be part of the control system or temporarily attached. The configuration system  170  configures each of the motor segments  122   a ,  122   b ,  122   c  through a learn run sequence and associated configuration process that is performed, after the ropeless elevator system  100  has been physically installed. The configuration system  170  may be an interface device such as, for example, an elevator operational panel, an elevator supervisory panel, a cellular phone, tablet, laptop, smartwatch, desktop computer or any similar device known to one of skill in the art. The configuration system  170  may be operatively connected to the control system via a hard wire or wirelessly through a wireless transmission method such as, for example, radio, microwave, cellular, satellite, or another wireless communication method. 
     In order to drive the elevator car  114 , one or more motor segments  122   a ,  122   b ,  122   c ,  122   d  can be configured to overlap the second part  118  of the elevator car  114  at any given point in time. In the example of  FIG. 2 , motor segment  122   d  partially overlaps the second part  118  (e.g., about 33% overlap), motor segment  122   c  fully overlaps the second part  118  (100% overlap), and motor segment  122   d  partially overlaps the second part  118  (e.g., about 66% overlap). There is no depicted overlap between motor segment  122   a  and the second part  118 . In some embodiments, the control system (system controller  125  and on-board controller  156 ) is operable to apply an electrical current to at least one of the motor segments  122   b ,  122   c ,  122   d  that overlaps the second part  118 . The system controller  125  may control the electrical current on one or more of the drive units  120   a ,  120   b ,  120   c ,  120   d  while receiving data from the on-board controller  156  via transceiver  138  based on a variety of sensors of the elevator system  110  including but not limited to load sensor  152  and sensors  160   a ,  160   b ,  160   c . The electrical current may apply an upward thrust force  139  to the elevator car  114  by injecting a current, thus propelling the elevator car  114  within the lane  113 . The current may be controlled via feedback control to ensure the current remains constant within a selected tolerance. The thrust produced by each motor segment  122   b ,  122   c ,  122   d  is dependent, in part, on the amount of overlap between the first part  116  with the second part  118 . The peak thrust is obtained for each motor segment  122   b ,  122   c ,  122   d  when there is maximum overlap of the first part  116  and the secondary portion  118 . 
     In traditional rotary drive, roped, elevator systems, the position of the elevator car could be determined accurately by a rotary encoder or similar device that measured the rotation of a rotor or spool and could determine the position of the car based on the amount/length of rope that was deployed. However, ropeless elevator systems void the applicability for rotary encoder and rotary motors as no rope or rotor is used. 
     Turning now to  FIG. 3 , a schematic view of a first embodiment of the sensing system of the present disclosure is shown. Car  114  is located within a lane  113  and configured to move in an upward or downward direction, depending on the control signals provided by drive units  120   a ,  120   b ,  120   c  and/or a system controller as described above with respect to  FIG. 2 . Each drive unit  120   a ,  120   b ,  120   c  is operatively connected to an associated motor segment  122   a ,  122   b ,  122   c  of the first part  116 . Although not shown, car  114  will include a second part (see elements  118  of  FIGS. 1 and 2 ) that will enable propulsion and driving of the car  114  within the lane  113 . 
     In operation, drive units  120   a ,  120   b ,  120   c  can energize the associated motor segments  122   a ,  122   b ,  122   c  of the first part  116 , respectively, to propel one or more elevator cars  114  upward within the lane  113 . Alternatively, the motor segments  122   a ,  122   b ,  122   c  of the first part  116  can operate as a regenerative brake to control descent of an elevator car  114  in the lane  113  and provide current back to the drive units  120   a ,  120   b ,  120   c , for example, to recharge an electrical system connected to the drive units  120   a ,  120   b ,  120   c.    
     The drive units  120   a ,  120   b ,  120   c  are connected to and/or retained on or near the structural member  119  of the lane  113 . Further, the motor segments  122   a ,  122   b ,  122   c  of the first part  116  are connected to and/or retained on or near the structural member  119  of the lane  113 . Although shown with the drive unit  120   a ,  120   b ,  120   c  separate from the respective motor segments  122   a ,  122   b ,  122   c  of the first part  116 , those of skill in the art will appreciate that the components may be configured as a single, integral unit, or sub-combinations thereof. To provide accurate location data and control within elevator system  110  a second system is provided. 
     Located on the structural member  119  may be one or more sensors  160   a ,  160   b ,  160   c  of a sensing system. The sensors  160   a ,  160   b ,  160   c  may also be located on the motor segments  122   b ,  122   c ,  122   d , which are located on the structural member  119 . As shown, the sensors  160   a ,  160   b ,  160   c  are on an opposite side of the lane  113  from respective, laterally adjacent drive units  120   a ,  120   b ,  120   c  and motor segments  122   a ,  122   b ,  122   c  of the first part  116 . However, this is not a limiting example but rather shown for ease of explanation, and those skilled in the art will appreciate that other configurations may be used without departing from the scope of the present disclosure. For example, the sensors  160   a ,  160   b ,  160   c  may be on the same side of lane  113 , adjacent to the respective drive units  120   a ,  120   b ,  120   c  and motor segments  122   a ,  122   b ,  122   c  of the first part  116 . Further, although shown in  FIG. 3  as a single lane  113 , those of skill in the art will appreciate that any number of lanes may employ sensing systems and configurations as described herein, and each lane may contain a plurality of sensors, such as an array or series of sensors. For example, each lane  113 ,  115 , and  117  of  FIG. 1  may be configured with the sensing system of  FIG. 3  and may span the entire length of the lanes  113 ,  115 , and  117 . 
     Sensors  160   a ,  160   b ,  160   c  are configured to be in electrical and digital communication with the respective drive unit  120   a ,  120   b ,  120   c  that is adjacent to it (i.e., at the same vertical position within the building or vertical position within the lane  113 ). For example, as shown in  FIG. 3 , the drive unit  120   a  at the top of the image is configured to be in communication with the sensor  160   a  at the top of the image. Similarly, drive unit  120   b  is configured to communicate with sensor  160   b , and drive unit  120   c  is configured to communicate with sensor  160   c . Accordingly, the proposed configuration is a lateral communication at the same level within the lane  113 . However, those of skill in the art will appreciate that other configurations may be employed without departing from the scope of the present disclosure. For example, a single drive unit may be in communication with more than one sensor, or vice versa. The communication between the drive units and the sensors, and vice versa, may be by any known means, such as a wired connection, a wireless connection, etc. The selection may be based on the needs and design of the elevator system  110  and/or the sensing system. For example, to provide a high bandwidth, and thus very quick and efficient communication between the component parts, a wired connection may be utilized. 
     The series or array of elevator car state sensors  160   a ,  160   b ,  160   c  are fixed to stationary points along the lane  113  and attached to the structural member  119 . The car state sensors  160   a ,  160   b ,  160   c  are configured to sense or determine a state of the elevator car, such as the position, velocity, and/or acceleration of an elevator car  114  as the elevator car  114  passes by the respective car state sensor  160   a ,  160   b ,  160   c . Thus, the location of the elevator car  114  within the lane  113  may be determined based upon the location sensed by the car state sensors  160   a ,  160   b ,  160   c . Thus, in some embodiments, the car state sensors are always active, and the control system selects which sensors to use for making state determinations based on the particular elevator car and/or on the car state sensor positions. In alternatively embodiments, car state sensors may become active based on proximity to a car, and thus the system may determine a car state based on active sensors within lane  113 , e.g., car state sensors that are activated when an elevator car is in proximity to the sensors. Further, in some embodiments, always active car state sensors may be configured to help identify and/or locate uncontrolled elevator cars. 
     Car state sensors, in accordance with embodiments of the present disclosure may be sensors configured to measure or determine a state space vector, which may be position, velocity, acceleration, motor magnetic angle, direction of movement, etc. When the state space vector is position, the car state sensor may directly determine the physical position or location of an elevator car. In other embodiments, the car state sensors may be configured to sense or determine the velocity of an elevator car and from this information position and/or acceleration may be derived. In other embodiments, the car state sensors may be configured to detect motor magnetic angle which is used for motor control, and from this car position, speed, and/or acceleration may be determined. However, in all embodiments, the car state sensors are configured to determine, whether directly or indirectly through derivation, at least the physical position or location of one or more elevator cars. Moreover, in some embodiments, the car state sensor(s) may be used to derive motor magnetic angle or other characteristics for motor control feedback. 
     As discussed above, the car state sensors  160   a ,  160   b ,  160   c  are configured to be in communication with the drive units  120   a ,  120   b ,  120   c . In some embodiments the car state sensors  160   a ,  160   b ,  160   c  may also be, or alternatively be, in communication with a larger control system or controller and/or a computerized system that controls the ropeless elevator system such as system controller  125  or the larger central control system described above. The array of car state sensors  160   a ,  160   b ,  160   c  is configured to enable the elevator system  110  to continually determine the position of the car  114  relative to the lane  113 , which may be in the form of car position data. The car position data may be incremental, such that when car  114  enters a sensing area of a new car state sensor the incremental change may be detected, i.e., moving vertically from a first car state sensor  160   a  to the next car state sensor  160   b  within the lane  113 . The sensing area of each car state sensor  160   a ,  160   b ,  160   c  may be defined as the physical space substantially proximate and/or adjacent to the physical location of the respective sensor. In some embodiments the car state sensors may be configured to always be active and in other embodiments the car state sensors may be configured to be active only when an elevator car is present in the sensing range or area of the sensor, as known in the art of sensors. 
     When sensing, an individual car state sensor  160   a ,  160   b ,  160   c  can start an incremental position count based on the movement of the car  114 . Because the position of the car state sensor  160   a ,  160   b ,  160   c  within the lane  113  is an absolute known location after learn run sequence (discussed further below), the measurement by the sensor can determine the exact location of a car  114 . Further, because the position of the car  114  relative to the car state sensors  160   a ,  160   b ,  160   c  may be incremental, i.e., changing in time, the elevator system  110  can determine a speed and/or an acceleration/deceleration based on the incremental change of position of the car  114  relative to a specific car state sensor  160   a ,  160   b ,  160   c.    
     Alternatively, in some embodiments the position of the elevator car  114  may be determined as an absolute location. For example, rather than relying on an incremental change of position relative to a sensor, the sensor can determine the exact location of the car  114 . In this example, a data point of the elevator car position can provide a unique value associated with a position within the lane  113 . In this way, both the location of the car state sensor  160   a ,  160   b ,  160   c  is absolutely known and the position of the car  114  is absolute relative to each car state sensor  160   a ,  160   b ,  160   c.    
     Further, in some embodiments, the car  114  may be configured with an identification mechanism  162  such that the car state sensors  160   a ,  160   b ,  160   c  can identify the specific car  114  that is present in the sensing area. Thus, not only can the elevator system  110  determine the position, speed, direction, and acceleration of a car  114  that is in the lane  113 , the elevator system  110  can also determine which specific car  114  is located at the specific location, traveling at what speed, in which direction, and the acceleration of the specific car  114 . In some alternative embodiments, as will be appreciated those of skill in the art, the identification mechanism  162  may coact with an additional sensor configured for this purpose, in addition to or instead of the car state sensors  160   a ,  160   b ,  160   c . For example, an RFID chip and sensor configuration may be employed to determine which specific elevator car is being sensed by the system. 
     In order to measure and/or sense an elevator car  114  portion, in some embodiments, for example as shown in  FIG. 3 , the position sensing system may employ a sensed element  164 . Sensed element  164  may be used as a baseline, guideline, reference, and may be configured as a scale, discrete target, and/or some other type of marking/device that may be sensed or registered by the car state sensors  160   a ,  160   b ,  160   c . In such embodiments, various technologies may be employed for sensing the presence and position of the car  114  by sensing or registering the scale  164  or a portion thereof. For example, such technologies may include, but are not limited to, IR/optical transmissive, IR/optical reflective, magnetic encoder, eddy current sensor, Hall Effect sensor, etc. The scale  164  may provide an incremental measuring wherein each box or marking of the scale  164  may indicate a particular position on the car  114 , and thus a car state sensor  160   a ,  160   b ,  160   c  can determine the movement of the car  114 , upward or downward, and also speed, direction, acceleration, and/or deceleration may be calculated. The scale  164  may enable the determination of absolute location when the elevator car  114  first passes or enters the sensing area of a sensor. Then, continued monitoring and/or measuring may provide incremental measurements. The incremental measurements may allow incremental quadrature wave analysis to be conducted while the car  114  is in front of or in proximity to a particular sensor, if the respective sensor is equipped to conduct an incremental quadrature wave analysis. 
     The scale  164  may be configured as a tape or other form of marking(s) that are configured to be read, sensed, registered, and/or detected by the car state sensors  160   a ,  160   b ,  160   c . For example, the scale  164  may be formed from a tape or other marking, such as paint, ink, dye, physical structure, etc. on the car  114 , that provides contrasting colors, shapes, indicators, etc. that are sensed, detected, or employed by the car state sensors  160   a ,  160   b ,  160   c . These examples are merely provided for explanatory purposes and other types of markings or scales may be used without departing from the scope of the present disclosure. 
     Turning now to  FIGS. 4-7 , various embodiments of the present disclosure are provided.  FIG. 4  shows a flow diagram illustrating a method  400  of operating the elevator system  110  of  FIG. 2-3  for a learn run sequence, according to an embodiment of the present disclosure. As may be appreciated by one of skill in the art, the method  400  may also be applicable to single car elevator systems in addition to the multi-car elevator system discussed and illustrated. Upon first installing an elevator system  110 , the car state sensors  160   a ,  160   b ,  160   c  must have locations assigned to them in the control system. These locations are the physical locations of the car state sensor  160   a ,  160   b ,  160   c  within the lanes  113 ,  115 ,  117 . Further, location of the motor segments  122   a ,  122   b ,  122   c  must also be determined. Having accurate locations for the cart state sensor  160   a ,  160   b ,  160   c  and the motor segments  122   a ,  122   b ,  122   c  helps to ensure that the control system is sending the proper commands to control the operation of the elevator car  114 . Once the location of the motor segments  122   a ,  122   b ,  122   c  has been determined, the associated drive  120   a ,  120   b ,  120   c  and system controller  125  also need to be configured with the motor segments  122   a ,  122   b ,  122   c  location to operate properly. The configuration helps to ensure that each motor segment  122   a ,  122   b ,  122   c  is identified properly and the corresponding drive  120   a ,  120   b ,  120   c , receives the correct software updates. 
     Referring now also to  FIG. 4 , which shows a flow diagram illustrating a method of operating the multi-car elevator system  110  of  FIG. 2-3  for a learn run sequence, according to an embodiment of the present disclosure. First off, at block  404 , once the elevator system  110  has been physically installed, the linear propulsion system moves the elevator car  114  through a lane  113 ,  115 ,  117  of the elevator shaft at a selected velocity. In an embodiment, the selected velocity may be a constant velocity. As described above, the linear propulsion system allows the elevator car  114  to move through the lane  113 ,  115 ,  117 . The linear propulsion system is composed of a first part  116  mounted in the lane  113 ,  115 ,  117  of the elevator shaft and a second part  118  mounted to the elevator car  114 , as seen in  FIG. 2 . The first part  116  comprises one or more motor segments  122   a ,  122   b ,  122   c  and the second part  118  comprises one or more permanent magnets  128 , as seen in  FIG. 2 . The second part  118  is configured to co-act with the first part to impart movement to the elevator car  114 . 
     Next, at block  406 , the sensor system detects the location of the elevator car  114  when it moves through the lane  113 ,  115 ,  117 . The sensor system, as described above, is composed of a plurality of sensed elements  164  disposed on the elevator car  114  and a plurality of car state sensors  160   a ,  160   b ,  160   c  disposed within the lane  113 ,  115 ,  117  as seen in  FIG. 3 . Then at block  408 , the control system determines at least one of a location of each of the car state sensors  160   a ,  160   b ,  160   c  relative to each other within the lane in response to a travel time of the elevator car  114 , a velocity of the elevator car  114 , a position of the elevator car  114  and a height H 1  of the elevator car  114 .  FIGS. 5 and 6  show an example of how an incremental sensor detection system may work to detect the location of car state sensors  160   a ,  160   b ,  160   c . As shown in  FIG. 5 , at time t ib  the top of elevator  114  has reached sensor  160   b . The position reported by each car state sensor  160   a ,  160   b ,  160   c  is measured and then the position is cross referenced at selected time instants to calculate a distance dp i , which is a distance between two car state sensors  160   a ,  160   b ,  160   c . Thus, in a non-limiting embodiment, the location p i  of car state sensors  160   b  relative to car state sensors  160   c  at location p i-1  may be expressed by the equation p i =p i-1 +dp i . Further, as shown in  FIG. 6 , at time t i-1t  the bottom of the elevator has now moved past car state sensors  160   c  at location p i-1  and the control system may now calculate: p i-1 +H 1 =+dp i-1 . In a non-limiting embodiment, an average may be used for an improved estimate, as shown the following equation: p i −p i-1 =(dp i +H 1 −dp i-1 )/2. 
     Next, at block  410  the control system determines at least one of the location, the length, and the phasing each of the motor segments  122   a ,  122   b ,  122   c  in response to back electromotive force (EMF) of the motor segments  122   a ,  122   b ,  122   c .  FIG. 7  shows how the EMF various drive motor segments of the motor segments  122   a (N−1),  122   b (N),  122   c (N+1) may change as the elevator car  114  moves past each motor segment  122   a ,  122   b ,  122   c . As the elevator car  114  moves at a selected velocity, the drives  120   a ,  120   b ,  120   c  corresponding to motor segments  122   a ,  122   b ,  122   c  are configured to monitor current and/or voltage. The position and velocity of the elevator car  114  is also measured and broadcasted to the each drives  120   a ,  120   b ,  120   c  and the control system. The control system and/or drives  120   a ,  120   b ,  120   c  will identify key transitions in their current/voltage waveforms  704  and use these transitions to calculate location and length of each of the motor segments  122   a ,  122   b ,  122   c . The back EMF increases as the elevator car  114  nears the motor segment  122   a ,  122   b ,  122   c  as seen by the peaks in the waveforms  704  in  FIG. 7 . The number and/or frequency of peaks in the waveforms  704  of  FIG. 7  may be used to determine the number and pitch of poles in the motor segments  122   a ,  122   b ,  122   c  in response to the velocity of the elevator  114 . The motor segments  122   a ,  122   b ,  122   c  and/or the controller may calculate the phasing of each motor segment in response to the sequence of peaks in the waveforms  704  and direction of movement of the elevator car  114 . In an embodiment, the EMF data may be shared and cross-referenced between each of the motor segments  122   a ,  122   b ,  122   c . Advantageously, sharing and cross-referencing will provide added consistency and/or accuracy. 
     Finally, at block  412 , each drive  120   a ,  120   b ,  120   c  is configured in response to the location of the respective motor segment  122   a ,  122   b ,  122   c . The configuration process may be performed by a configuration system  170  operably connected to the elevator system  110 . The configuration system  170  may assign each drives  120   a ,  120   b ,  120   c  an address dynamically through an assignment process, such as, for example, a dynamic host configuration protocol (DHCP). The drives  120   a ,  120   b ,  120   c  may be discovered during the configured by getting the data from the DHCP or scanning for available drives  120   a ,  120   b ,  120   c  using a method, such as, for example address resolution protocol (ARP), ping, and zeroconf. The configuration system cross references the address of drive  120   a ,  120   b ,  120   c  with the location in the lane  113 ,  115 ,  117  of each motor segment  122   a ,  122   b ,  122   c  and sends the appropriate set of parameters to operate to each motor segment  122   a ,  122   b ,  122   c.    
     Advantageously, embodiments of the present disclosure provide information that enables the elevator system to actively and precisely locate the sensors and motor segments in a multicar, ropeless elevator system. Further advantageously, embodiments of the present disclosure provide information that enables the elevator system to actively configure the motor segments. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. While the description has been presented for purposes of illustration and description, it is not intended to be exhaustive or limited to embodiments in the form disclosed. Many modifications, variations, alterations, substitutions or equivalent arrangement not hereto described will be apparent to those of ordinary skill in the art without departing from the scope of the disclosure. Additionally, while the various embodiments have been described, it is to be understood that aspects may include only some of the described embodiments. Accordingly, the disclosure is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.