Abstract:
Embodiments are directed to reducing at least one dynamically generated error in terms of an actual position of an elevator car, comprising: triggering an inertial measurement unit (IMU) to compute a position of an elevator car of an elevator system, obtaining a position of a correcting vane in a hoist-way of the elevator system, obtaining a position of the elevator car as determined by an encoder of the elevator system, and estimating the position of the elevator car based on the computation of the position by the IMU, the position of the correcting vane, and the position of the elevator car as determined by the encoder.

Description:
BACKGROUND 
       [0001]    In a given elevator system or environment, the actual landing location of an elevator car might not correspond to a commanded landing location. A deviation between the actual landing location of the elevator car and the commanded landing location may have an impact on the operation of the elevator or users (e.g., riders) of the elevator. For example, if an elevator car is ascending an elevator shaft or hoist-way and stops short of an intended landing location (e.g., a landing floor), a lip or ridge may exist between the elevator car and the floor. Such a lip may cause a rider to clip her shoe when exiting the elevator car, potentially causing her to stumble. Such a lip may also make it more difficult to remove heavy objects from the elevator. For example, a bellhop pushing a cart of luggage may need to push the cart harder to compensate for the lip. 
         [0002]    An improvement in terms of landing accuracy, or a minimization or reduction in terms of a difference between the actual landing location of an elevator car and the commanded landing location of the elevator car, is needed. 
       BRIEF SUMMARY 
       [0003]    An embodiment of the disclosure is directed to a method for reducing at least one dynamically generated error in terms of an actual position of an elevator car, comprising: triggering an inertial measurement unit (IMU) to compute a position of an elevator car of an elevator system, obtaining a position of a correcting vane in a hoist-way of the elevator system, obtaining a position of the elevator car as determined by an encoder of the elevator system, and estimating the position of the elevator car based on the computation of the position by the IMU, the position of the correcting vane, and the position of the elevator car as determined by the encoder. 
         [0004]    An embodiment of the disclosure is directed to a system comprising: an elevator car comprising a actuator, a correcting vane coupled to a hoist-way and configured to be triggered by the actuator when the elevator car traverses the hoist-way such that the actuator encounters the correcting vane, an inertial measurement unit (IMU) configured to compute a position of the elevator car responsive to the correcting vane being triggered by the actuator, and a controller comprising a processor configured to estimate a position of the elevator car based on a position of the correcting vane in the hoist-way, the position of the elevator car computed by the IMU, and a position of the elevator car as determined by an encoder. 
         [0005]    An embodiment is directed to an apparatus comprising: at least one processor; and memory having instructions stored thereon that, when executed by the at least one processor, cause the apparatus to: obtain, from the memory, a position of a correcting vane in a hoist-way of an elevator system, obtain a position of an elevator car of the elevator system as determined by an encoder of the elevator system, and estimate a position of the elevator car between the position of the correcting vane and a position of a commanded landing floor using Kalman filtering applied to: a computation of the position of the elevator car by an inertial measurement unit (IMU), the position of the correcting vane, and the position of the elevator car as determined by the encoder. 
         [0006]    Additional embodiments are described below. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The present disclosure is illustrated by way of example and not limited in the accompanying figures in which like reference numerals indicate similar elements. 
           [0008]      FIG. 1  illustrates an exemplary elevator system in accordance with one or more embodiments of the disclosure; 
           [0009]      FIG. 2  illustrates an exemplary inertial measurement unit (IMU) in accordance with one or more embodiments of the disclosure; 
           [0010]      FIG. 3  illustrates exemplary correcting vanes about a landing floor in accordance with one or more embodiments of the disclosure; 
           [0011]      FIG. 4  illustrates an exemplary system for calculating an elevator car position in accordance with one or more embodiments of the disclosure; and 
           [0012]      FIG. 5  illustrates a flow chart of an exemplary method in accordance with one or more embodiments of the disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    Exemplary embodiments of apparatuses, systems and methods are described for safely and effectively controlling an elevator. In some embodiments, a difference or deviation between an actual landing location of an elevator car and a desired or commanded landing location of the elevator car may be minimized or reduced. In some embodiments, an actual position of the elevator car may be determined based on one or more inputs. Such inputs may be derived from, or obtained from, one or more inertial measurement units (IMUs), one or more transducers/encoders, and/or one or more correcting vanes. 
         [0014]    It is noted that various connections are set forth between elements in the following description and in the drawings (the contents of which are included in this disclosure by way of reference). It is noted that these connections in general and, unless specified otherwise, may be direct or indirect and that this specification is not intended to be limiting in this respect. In this respect, a coupling between entities may refer to either a direct or an indirect connection. 
         [0015]      FIG. 1  illustrates a block diagram of an exemplary elevator system  100  in accordance with one or more embodiments. The organization and arrangement of the various components and devices shown and described below in connection with the elevator system  100  is illustrative. In some embodiments, the components or devices may be arranged in a manner or sequence that is different from what is shown in  FIG. 1 . In some embodiments, one or more of the devices or components may be optional. In some embodiments, one or more additional components or devices may be included. 
         [0016]    The system  100  may include an elevator car  102  that may be used to convey, e.g., people or items up or down an elevator shaft or hoist-way  104 . The elevator car  102  may include an input/output (I/O) interface that may be used by users or riders of the system  100  to select a destination or target landing floor, which may be specified in terms of a floor number. The elevator car  102  may include one or more panels, interfaces, or equipment that may be used to facilitate emergency operations. 
         [0017]    The elevator car  102  may be coupled to a motor  106 . The motor  106  may provide power to the system  100 . In some embodiments, the motor  106  may be used to propel or move the elevator car  102 . 
         [0018]    The motor  106  may be coupled to an encoder  108 . The encoder  108  may be configured to provide a position of a machine or motor  106  as it rotates. The encoder  108  may be configured to provide a speed of the motor  108 . For example, delta positioning techniques, potentially as a function of time, may be used to obtain the speed of the motor  108 . Measurements or data the encoder  108  obtains from the motor  106  may be used to infer or determine a position of the elevator car  102  as described further below. 
         [0019]    The system  100  may include a governor  110 . The governor  110  may be configured to control the speed of the elevator car  102  by controlling a speed of one or more pulleys (not shown in  FIG. 1 ). The governor  110  may be coupled to the elevator car  102  by one or more tension members  112 . 
         [0020]    In some embodiments, the elevator car  102  may include, or be associated with, one or more actuators  114 . The one or more actuators  114  may be operative in conjunction with one or more vanes (e.g., correcting vanes)  116 . For example, actuator  114  may be a magnet and vane  116  may include a Hall effect sensor. A vane  116  may include a sensor and may be positioned on the hoist-way  104 . When an actuator  114  crosses paths with or encounters a vane  116 , such as when the elevator car  102  is moving or traversing the hoist-way  104 , the vane  116  may be triggered to, in turn, trigger one or more inertial measurement units (IMUs)  124  as described further below. 
         [0021]    In some embodiments, a first of the actuators  114  may be located at or near the top of the elevator car  102  and may be used to trigger a vane  116  when the elevator car  102  is ascending in the hoist-way  104 . In some embodiments, a second of the actuators  114  may be located at or near the bottom of the elevator car  102  and may be used to trigger a vane  116  when the elevator car  102  is descending in the hoist-way  104 . 
         [0022]    The elevator car  102  may include, or be associated with, a controller  118 . In some embodiments, the controller  118  may include at least one processor  120 , and memory  122  having instructions stored thereon that, when executed by the at least one processor  120 , cause the controller  118  to perform one or more acts, such as those described herein. In some embodiments, the processor  120  may be at least partially implemented as a microprocessor (uP). In some embodiments, the memory  122  may be configured to store data. Such data may include position data as described further below. 
         [0023]    In some embodiments, the controller  118  may be configured to estimate a position of the elevator car  102 . The controller  118  may base the estimate of the position on one or more inputs. The inputs may be obtained from, or based on, one or more encoders  108 , one or more vanes  116 , and one or more IMUs  124 . 
         [0024]    The IMU  124  may include one or more components or devices. For example, and as shown in  FIG. 2 , the IMU  124  may include one or more of an accelerometer  202 , a gyroscope  204 , a magnetometer  206 , a pressure sensor or barometer  208 , and a temperature sensor or thermometer  210 . The structure and function of each of the components  202 - 210  would be known to one of skill in the art, and as such, a complete description of the components  202 - 210  is omitted for the sake of brevity. The components  202 - 210  may be used to characterize the motion or position of the elevator car  102  as described further below. 
         [0025]    Referring to  FIGS. 1-2 , the IMU  124  (in potential combination with the encoder  108 , the vane  116 , and/or the controller  118 ) may be used to compensate for errors in the position of the elevator car  102 . Such errors may be a result of dynamic effects, such as a stretching of the tension member  112  or rotation or tilt of the elevator car  102  as the elevator car  102  slows down or decelerates to zero speed or velocity, which may be the case when the elevator car  102  approaching a landing floor. The tension member  112  may include one or more of a rope, a belt, and/or a cable. The tension member  112  may be associated with one or more elevator suspension systems or governor-rope tension systems. 
         [0026]    In some embodiments, the IMU  124  may, under normal operating conditions, accumulate errors due to one or more factors. For example, such factors may include a numeric integration of bias offsets and environmental factors (e.g., temperature drift on sub-components of the IMU  124 ). The IMU  124  may need to be recalibrated (or reset) at strategic positions and/or points in time. In some embodiments, a reference system (e.g., an absolute reference system) may be used to recalibrate the IMU  124 . The IMU  124  may be recalibrated when the car  102  is stationary (e.g., at zero speed and/or velocity) at a floor or otherwise. In some embodiments, the reference system may be mounted in a pit of the hoist-way  104 , potentially away or apart from any significant motion. The reference system may provide known reference values to which outputs of the IMU  124  should be recalibrated when the car  102  is stopped. For example, the reference system may provide axial reference values to which the IMU  124  should be calibrated under stationary (non-moving) conditions. 
         [0027]    The IMU  124  may be configured to provide a profile of the elevator car  102 &#39;s movement along any number of axes. For example, a pitch and roll of the elevator car  102  may be provided in connection with a Cartesian coordinate system (e.g., x-y-z axes), a polar coordinate system, a spherical coordinate system, a cylindrical coordinate system, etc. In some embodiments, a coordinate system to use may be selected. The selection may be specified by a manufacturer of one or more devices, by an operator of an elevator system (e.g., an owner or manager of a building), or by an end user. Parameters (e.g., speed, distance, position, tilt, and rotation) for the elevator car  102  may be provided by the IMU  124  in terms of one or more dimensions (e.g., three-dimensional space). 
         [0028]    Referring to  FIGS. 1 and 3 , an illustration of vanes  116 - a  and  116 - c  about a floor  302  is shown. The floor  302  may correspond to a position of a reference floor ‘B’, and may be representative of an intended or commanded landing or stopping point for the elevator car  102  as the elevator car  102  traverses the hoist-way  104 . The labels ‘A’ and ‘C’ in  FIG. 3  may correspond to the positions of the vanes  116 - a  and  116 - c  along the hoist-way  104 , respectively. The distance  304  between the correcting vane  116 - a  and the floor  302  and the distance  306  between the correcting vane  116 - c  and the floor  302  may be known based on a prior run of the elevator car  102 . In this respect, the positions A and C of the vanes  116 - a  and  116 - c  relative to the floor  302  also may be known. The positions A and C of the vanes  116 - a  and  116 - c  may be stored in one or more memories, such as the memory  122 . 
         [0029]    Assuming a vertical orientation as shown in  FIG. 3 , the vane  116 - a  may be used to track the elevator car  102  as the elevator car  102  descends in the hoist-way  104  towards the floor  302 . Similarly, the vane  116 - c  may be used to track the elevator car  102  as the elevator car  102  ascends in the hoist-way  104  towards the floor  302 . 
         [0030]    Turning now to  FIG. 4 , a filter  402  is shown. The filter  402  may be implemented by, or in connection with, the controller  118  of  FIG. 1 . The filter  402  may correspond to a sensory fusion function. In some embodiments, the filter  402  may correspond to, or implement, Kalman filtering (e.g., linear or non-linear Kalman filtering). 
         [0031]    The filter  402  may generate an estimated position output, which may correspond to an estimated position of the elevator car  102  at one or more points in time. The estimated position output may be based on one or more inputs. For example, the estimated position output may be based on an estimated position provided by one or more IMUs (e.g., IMU  124 ), a (primary) position provided by one or more transducers or encoders (e.g., encoder  108 ), and a position associated with one or more vanes (e.g., vane  116 ). 
         [0032]    Turning now to  FIG. 5 , a flow chart of an exemplary method is shown in accordance with one or more embodiments. The method of  FIG. 5  may be used to determine or estimate a position of an elevator car (e.g., the elevator car  102 ). The method of  FIG. 5  may be executed by one or more devices or components, such as the controller  118  of  FIG. 1 . 
         [0033]    In block  502 , an IMU (e.g., IMU  124 ) may be triggered to compute a position of an elevator car (e.g., elevator car  102 ) relative to a vane (e.g., vane  116 - a  or  116 - c ). The IMU may be triggered in response to the elevator car approaching a stopping floor (e.g., floor  302 ) and the elevator car (or more specifically, an actuator  114 ) encountering the vane. 
         [0034]    The IMU may compute the position of the elevator car as an incremental position or offset relative to the location of the vane. As described above, the position of the vane may be known from a prior run. In block  504 , the position of the vane may be obtained from memory (e.g., memory  122 ). 
         [0035]    In block  506 , a position of the elevator car as determined by a transducer or encoder (e.g., encoder  108 ) may be obtained. 
         [0036]    In block  508 , a position or location of the elevator car may be determined. The determination of block  508  may be based on the position computed by the IMU (e.g., block  502 ), the obtained vane position (e.g., block  504 ), and the position of the elevator car as determined by the encoder (e.g., block  506 ). In some embodiments, the determination of block  508  may be based on one or more filtering operations, such as described above in connection with  FIG. 4 . 
         [0037]    In block  510 , the IMU may be recalibrated. The IMU may be recalibrated to eliminate drift in association with, e.g., one or more components or devices included in the IMU. 
         [0038]    The method illustrated in connection with  FIG. 5  is illustrative. In some embodiments, one or more of the blocks or operations (or portions thereof) may be optional. In some embodiments, the operations may execute in an order or sequence different from what is shown. In some embodiments, one or more additional operations not shown may be included. 
         [0039]    In some embodiments, one or more measurements, computations, or determinations may be based on one or more timestamps. For example, if an IMU exists as a separate node on a network (e.g., a controller area network (CAN) bus) that allows for time synchronization, the IMU may provide both an estimated elevator car position and a corresponding timestamp. 
         [0040]    In some embodiments, the IMU may determine the position of the elevator car (e.g., in connection with block  508 ), and may optionally provide that determination to a controller (e.g., the controller  118 ). Such a determination may be provided if, for example, the IMU is a separate device or node on a network and the IMU has access to data from the primary position transducer or encoder as well as a learned landing table, which may include information regarding position(s) of the vane(s). 
         [0041]    Embodiments of the disclosure may maximize or improve elevator performance. Such maximization or improvement of performance may include compensating for, and minimizing or reducing, dynamically generated errors in the true or actual position of an elevator car that might otherwise be reported by a primary position transducer or encoder. 
         [0042]    Embodiments may be tied to one or more particular machines. For example, an IMU or controller may be configured to determine or compute a position of an elevator car. The determination or computation may correspond to an estimate of the position of the elevator car. 
         [0043]    In some embodiments various functions or acts may take place at a given location and/or in connection with the operation of one or more apparatuses, systems, or devices. For example, in some embodiments, a portion of a given function or act may be performed at a first device or location, and the remainder of the function or act may be performed at one or more additional devices or locations. 
         [0044]    Embodiments may be implemented using one or more technologies. In some embodiments, an apparatus or system may include one or more processors, and memory storing instructions that, when executed by the one or more processors, cause the apparatus or system to perform one or more methodological acts as described herein. In some embodiments, one or more input/output (I/O) interfaces may be coupled to one or more processors and may be used to provide a user with an interface to an elevator system. Various mechanical components known to those of skill in the art may be used in some embodiments. 
         [0045]    Embodiments may be implemented as one or more apparatuses, systems, and/or methods. In some embodiments, instructions may be stored on one or more computer-readable media, such as a transitory and/or non-transitory computer-readable medium. The instructions, when executed, may cause an entity (e.g., an apparatus or system) to perform one or more methodological acts as described herein. 
         [0046]    Aspects of the disclosure have been described in terms of illustrative embodiments thereof. Numerous other embodiments, modifications and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure. For example, one of ordinary skill in the art will appreciate that the steps described in conjunction with the illustrative figures may be performed in other than the recited order, and that one or more steps illustrated may be optional.