Abstract:
A device for detecting the position of a shifter lever in a motor vehicle includes a 2D magnetic sensor and a dual magnet. The shifter lever is rotatably movable around a pivot axis and translationally moveable in a direction generally perpendicular to the pivot axis. The dual magnet coupled to the shifter lever at the pivot point and disposed proximate the 2D magnetic sensor. The dual magnet has a first magnet and a second magnet. The first magnet has a first pole pair and the second magnet has a second pole pair. The first pole pair is offset from the second pole pair.

Description:
FIELD 
       [0001]    The invention relates generally to a shift detection system for a motor vehicle, and more particularly to a shift detection system having a 2D sensor for detecting a plurality of positions of a shifter lever. 
       BACKGROUND 
       [0002]    The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art. 
         [0003]    In a motor vehicle equipped with an automatic transmission, a shifter mechanism typically includes a shifter or control lever mounted within the motor vehicle&#39;s passenger compartment. The shifter lever is used by an operator of the motor vehicle to select one of a plurality of transmission operating modes. For example, these transmission operating modes may include park (P), reverse (R), neutral (N), drive (D), a low gear or manual mode (M), manual shift up (M+), and manual shift down (M−). To select these modes, the shifter lever may be moved about two axes of rotation—one for the P, R, N, D positions and another for the M, M+, M− positions, also known as an H-shift pattern. 
         [0004]    In order to properly command the operating mode of the transmission, it is important to precisely detect the position of the shifter lever. One solution is to detect the position of the shifter lever using a 3D type Hall-effect sensor which detects the movement of the shifter lever in the X, Y, and Z axes of the sensors. While these systems are useful for their intended purpose, there is a need in the art to reduce the costs associated with the relatively expensive 3D type Hall-effect sensor technology while maintaining the ability to accurately and precisely detect the position of the shifter lever. 
       SUMMARY 
       [0005]    A device for detecting the position of a shifter lever in a motor vehicle is provided. The shifter lever is rotatably movable around a pivot axis and translationally moveable in a direction generally perpendicular to the pivot axis. The device includes a 2D magnetic sensor and a dual magnet coupled to the shifter lever at the pivot point and disposed proximate the 2D magnetic sensor. The dual magnet has a first magnet and a second magnet. The first magnet has a first pole pair and the second magnet has a second pole pair. The first pole pair is offset from the second pole pair. 
         [0006]    In one aspect, the dual magnet is generally cylindrically shaped and the first pole pair is circumferentially offset from the second pole pair. 
         [0007]    In another aspect, the first pole pair is offset from the second pole pair by approximately 180 degrees so that the magnetic field of the first pole pair is substantially reversed relative to the magnetic field of the second pole pair. 
         [0008]    In another aspect, the first magnet includes a first N-pole and a first S-pole, the second magnet includes a second N-pole and a second S-pole, and the first N-pole is directly axially adjacent the second S-pole and the first S-pole is directly axially adjacent the second N-pole. 
         [0009]    In another aspect, the 2D magnetic sensor is a Hall effect sensor or a giant magneto-resistive sensor. 
         [0010]    In another aspect, the first pole pair is circumferentially offset from the second pole pair by approximately 25 degrees to approximately 45 degrees. 
         [0011]    In another aspect, the 2D magnetic sensor is an anisotropic magneto-resistive sensor. 
         [0012]    In another aspect, the first magnet is disposed axially adjacent the second magnet. 
         [0013]    In another aspect, the first and second magnets are disposed on a first cylindrical half of the dual magnet. 
         [0014]    In another aspect, the 2D sensor is configured to sense a movement of the dual magnet in both a rotational and a translational direction. 
         [0015]    In another aspect, the dual magnet is coaxial with the pivot axis of the shifter lever. 
         [0016]    A shifter assembly for a motor vehicle is also provided. The shifter assembly includes a housing, a shifter lever having a pivot point that defines an axis, wherein the shifter lever is configured to pivot about the axis and to translate along the axis, a dual magnet connected to the shifter lever at the pivot point, the dual magnet having a first magnet and a second magnet, the first magnet having a first pole pair and the second magnet having a second pole pair, wherein the first pole pair is offset from the second pole pair, and a 2D sensor connected to the housing and disposed proximate the dual magnet, wherein the 2D sensor is configured to sense a change of position of the dual magnet as the shifter lever pivots or translates. 
         [0017]    In one aspect, the 2D sensor detects a change in a magnetic field as the dual magnet is pivoted or translated by the shifter lever. 
         [0018]    In another aspect, the translation and pivoting of the shifter lever corresponds to one of a P, R, N, D, M+, M, and M− positions. 
         [0019]    In another aspect, the dual magnet is generally cylindrically shaped and the first pole pair is offset from the second pole pair by approximately 180 degrees such that the magnetic field of the first pole pair is substantially reversed relative to the magnetic field of the second pole pair. 
         [0020]    In another aspect, the first magnet includes a first N-pole and a first S-pole, the second magnet includes a second N-pole and a second S-pole, and the first N-pole is directly axially adjacent the second S-pole and the first S-pole is directly axially adjacent the second N-pole. 
         [0021]    In another aspect, the 2D magnetic sensor is a Hall effect sensor or a giant magneto-resistive sensor. 
         [0022]    In another aspect, the first pole pair is circumferentially offset from the second pole pair by approximately 25 degrees to approximately 45 degrees and the 2D magnetic sensor is an anisotropic magneto-resistive sensor. 
         [0023]    In another aspect, the 2D sensor is in communication with an electronic controller. 
         [0024]    Another shifter assembly for a motor vehicle is provided. The shifter assembly includes a housing, a shifter lever having a pivot point that defines an axis, wherein the shifter lever is configured to pivot about the axis and to translate along the axis to one of a P, R, N, D, M+, M, and M− positions, a cylindrical dual magnet connected to the shifter lever at the pivot point, the cylindrical dual magnet having a first magnet and a second magnet each disposed on a first half of the cylindrical dual magnet, the first magnet having a first pole pair and the second magnet having a second pole pair, wherein the first pole pair is offset from the second pole pair, and a 2D sensor connected to the housing and disposed proximate the dual magnet, wherein the 2D sensor is configured to sense a change of position of the dual magnet as the shifter lever pivots or translates. 
         [0025]    Further aspects, examples, and advantages will become apparent by reference to the following description and appended drawings wherein like reference numbers refer to the same component, element or feature. 
     
    
     
       DRAWINGS 
         [0026]    The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. 
           [0027]      FIG. 1  is a side perspective view of an example of a shift detection system employed with an exemplary shifter assembly; 
           [0028]      FIG. 2  is a top perspective view of the shift detection system; 
           [0029]      FIG. 3  is an end view of the shift detection system; and 
           [0030]      FIG. 4  is a top perspective view of another example of a shift detection system. 
       
    
    
     DETAILED DESCRIPTION 
       [0031]    The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. 
         [0032]    With reference to  FIG. 1 , a shift detection device is generally indicated by reference number  10 . The shift detection device  10  is employed with an exemplary shifter assembly  12  mounted within a motor vehicle (not shown). The shifter assembly  12  is controlled by an operator of the motor vehicle to select one of a plurality of shift positions, indicated by the H-gate shift pattern  14 . Each of the shift positions corresponds to an operating mode of a transmission (not shown) associated with the motor vehicle. In the example provided, the H-gate shift pattern  14  includes a park (P), reverse (R), neutral (N), drive (D), a manual mode (M), manual shift up (M+), and manual shift down (M−). It should be appreciated that the number of shift positions, as well as the associated transmission operating mode, may vary without departing from the scope of the present example. For example, the manual modes M, M+, and M− may be replaced with high gear and low gear operating modes. 
         [0033]    The shifter assembly  12  generally includes a shifter lever  16  mounted to a support collar  18 . The shifter lever  16  is capable of translating along a pivot axis  20  and is capable of pivoting about the pivot axis  20 . Various ways of mounting the shifter lever  16  within the shifter assembly  12  in order to allow the shifter lever  16  to pivot and translate may be used without departing from the scope of the present example. The shifter lever  16  includes a detent arm  22  that engages a plurality of detents  24 , only one of which is shown, formed in a base  26 . The detents  24  are positioned in the base  26  to provide a mechanical detent to each of the plurality of shift positions in the H-gate shift pattern  14 . The selection of the P, R, N, D positions are achieved by pivoting the shifter lever  16  when the shifter lever  16  is translated cross-car to the left. The selection of the M, M+, M− positions are achieved by pivoting the shifter lever  16  when the shifter lever  16  is translated cross-car to the right. 
         [0034]    The shift detection system  10  is operable to detect the shift position of the shifter lever  16  as it is translated and pivoted in the H-gate shift pattern  14 . The shift detection system  10  includes a dual magnet  30  and a 2D magnetic sensor  32 . The dual magnet  30  is connected to the shifter lever  16  at a pivot point  34  of the shifter lever  16 . Thus, the dual magnet  30  is concentric to the pivot axis  20 . Translation of the shifter lever  16  results in translation of the dual magnet  30  along the axis  20  while pivoting of the shifter lever  16  results in rotation of the dual magnet  30  about the axis  20 . The 2D magnetic sensor  32  is mounted on a fixed member or housing  36  proximate the shift lever  16 . The 2D magnetic sensor  32  may be positioned in close proximity to the dual magnet  30 . 
         [0035]    The 2D sensor  32  is configured to only measure the rotations of the magnetic field produced by the dual magnet  30 . In one example, the 2D magnetic sensor  32  is preferably a 2D Hall-effect sensor or a giant magneto-resistive sensor. In another example, the 2D magnetic sensor  32  is preferably an anisotropic magneto-resistive sensor. The type of 2D magnetic sensor employed is dependent on the configuration of the dual magnet  30 , as will be described below. The 2D magnetic sensor  32  may be in electronic communication with a controller  38 . The controller  38  is a non-generalized, electronic control device having a preprogrammed digital computer or processor, memory or non-transitory computer readable medium used to store data such as control logic or instructions, and at least one I/O peripheral. The processor is configured to execute the control logic or instructions. In one example, the controller  38  is a transmission control module operable configured to control the associated transmission based on data signals sent from the 2D magnetic sensor  32  indicative of the position of the shift lever  16 . Thus, if the 2D magnetic sensor  32  communicates data to the controller  38  that the shift lever  16  is in the park position, then the controller  38  commands the transmission into a park mode of operation. Alternatively, the controller  38  may be a separate unit from the transmission control module or be integrated with another motor vehicle control module, such as an engine control module, body control module, etc. 
         [0036]    Turning now to  FIG. 2 , and with continued reference to  FIG. 1 , the dual magnet  30  is generally cylindrical in shape having a longitudinal axis  40 . The dual magnet  30  includes a first magnet  42  and a second magnet  44 . The first magnet  42  has a first pole pair with a first North pole (N-pole) and a first South pole (S-pole). The second magnet has a second pole pair with a second N-pole and a second S-pole. The first magnet  42  is disposed axially adjacent the second magnet  44 . However, the second magnet  44  is flipped 180 degrees relative to the first magnet  42  such that the first N-pole is directly axially adjacent the second S-pole and the first S-pole is directly axially adjacent the second N-pole. Thus the first magnet  42  produces a magnetic field that is oriented in a reverse direction relative to a magnetic field produced by the second magnet  44 . In this configuration of the dual magnet  30 , the 2D magnetic sensor  32  is a 2D Hall-effect sensor or a giant magneto-resistive sensor. 
         [0037]    Referring now to  FIG. 3 , the first and second magnets  42 ,  44  are disposed on a first cylindrical half  30 A of the dual magnet  30 . Thus, the magnetic field produced by each of the first and second magnets  42 ,  44  extends above the first cylindrical half  30 A. The 2D magnetic sensor  32  is preferably located so that the 2D magnetic sensor  32  is centered on the longitudinal axis  40  and above the first cylindrical half  30 A. 
         [0038]    With combined reference to  FIGS. 1-3 , to select a shift position, an operator of the motor vehicle moves the shifter lever  16  within the H-gate shift pattern  14  to one of the P, R, N, D and M, M+, M− shift positions. Translation of the shifter lever  16  cross-car between the left position (corresponding to the P, R, N, D positions) and right position (corresponding to the M, M+, M− positions) switches which of the first and second magnets  42 ,  44  is closer to the 2D magnetic sensor  32 . Due to the reverse magnetic fields produced by the first and second magnets  42 ,  44 , the 2D magnetic sensor  32  is able to detect which of the first and second magnets  42 ,  44  is closer to the 2D magnetic sensor  32 . As the shifter lever  16  is then pivoted to one of the shift positions in the H-gate shift pattern  14 , the 2D magnetic sensor  32  detects the rotation of the magnetic fields as the dual magnet  30  rotates with the shifter lever  16 . Each shift position in the H-gate shift pattern  14  has associated with it a particular magnetic field orientation and rotation. Thus, the controller  38  is able to determine the position of the shifter lever  16  based on the rotation of the magnetic field of whichever of the first and second magnets  42 ,  44  is closer to the 2D magnetic sensor  32 . This information is then used to command the associated operating mode to the transmission of the motor vehicle. 
         [0039]    Turning to  FIG. 4 , an alternate dual magnet configuration is indicated by reference number  30 ′. The dual magnet  30 ′ also includes the first magnet  42  and the second magnet  44 . However, the first and second magnets  42 ,  44  have a different orientation than that of the dual magnet  30  shown in  FIGS. 1-3 . In the dual magnet  30 ′, the first and second magnets  42 ,  44  have first and second N-S pole pairs, however, the second magnet  44  is circumferentially offset from the first magnet  42  by an angle theta. Angle theta is measured relative to the longitudinal axis  40  and is the angle between a fixed point of the first N-pole of the first magnet  42  and a corresponding fixed point on the second N-pole of the second magnet  44 . Alternatively, angle theta may be the angle between a fixed point of the first S-pole of the first magnet  42  and a corresponding fixed point on the second S-pole of the second magnet  44 . In a preferred example, angle theta is approximately 25 degrees to approximately 45 degrees. In this configuration, the 2D magnetic sensor  32  is preferably an anisotropic magneto-resistive sensor. The dual magnet  30 ′ operates in substantially the same manner as the dual magnet  30 . However, by circumferentially offsetting the first and second magnets  42 ,  44 , the 2D magnetic sensor  32  detects a wider range of magnetic field rotations such that each of the shift positions in the H-gate shift pattern  14  is associated with a unique field rotation. 
         [0040]    The description of the invention is merely exemplary in nature and variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.