Abstract:
A shifter assembly in a motor vehicle includes a shifter housing. A shifter lever having first and second ends is coupled to the shifter housing at the second end. The shifter lever is rotatable about a pivot axis and is translatable parallel to the pivot axis. The shifter assembly has first and second 2-Dimensional (2D) magnetic sensors, and first and second magnets. The first magnet is coupled to the shifter lever between the first and second ends, proximate the first sensor, and has a first magnetic field in radial alignment with the shifter lever. The second magnet is coupled to the shifter lever between the first and second ends, proximate the second sensor, and has a second magnetic field perpendicular to the first magnetic field. The first sensor detects an angular displacement of the first magnetic field, and the second sensor detects an axial displacement of the second magnetic field.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application No. 62/341,944, filed on May 26, 2016, the entire contents of which are incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The present invention relates to a shifter assembly for a motor vehicle, and in particular, to a shifter assembly for a motor vehicle having an anisotropic magnetoresistance sensor that detects a shifter lever position. 
       BACKGROUND 
       [0003]    The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art. 
         [0004]    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), and may, in some configurations, include a low gear or manual mode (M), manual shift up (M+), and manual shift down (M−). To select transmission modes, the operator of the motor vehicle moves the shifter lever about an axis of rotation corresponding to the P, R, N, D positions. The shifter lever may, in some configurations, also be moveable about a second axis of rotation corresponding to the M, M+, M—positions. A shifter position signal is generated by a shifter location system and transmitted from the shifter location system to the transmission, where the transmission selects the drive mode corresponding to the shifter lever position. The shifter position signal may be a physical signal, or an electronic signal. Typically, the shifter position signal may be generated by a combination of Hall-effect sensors or optical sensors particularly arranged to provide a 3-D map of the shifter lever position. While these systems are useful for their intended purpose, there is a need in the art for improved shifter location systems that do not increase the cost or packaging size of the shifter location system, while also increasing the accuracy and robustness of the system and providing additional redundant safety features. 
       SUMMARY 
       [0005]    In one aspect of the present invention, a shifter assembly in a motor vehicle includes a shifter housing. The shifter assembly further includes a shifter lever having a first end and a second end, the shifter lever coupled to the shifter housing at the second end. The shifter lever is rotatable about a pivot axis at the second end and is translatable in a direction generally parallel to the pivot axis. The shifter assembly further includes a first 2-Dimensional (2D) magnetic sensor. The shifter assembly further includes a first magnet having a first magnetic field. The first magnet is coupled to the shifter lever between the first end and the second end, and the first magnet is disposed proximate the first 2D magnetic sensor. The shifter assembly further includes a second 2D magnetic sensor. The shifter assembly further includes a second magnet having a second magnetic field. The second magnet is coupled to the shifter lever between the first end and the second end, and the second magnet is disposed proximate the second 2D magnetic sensor. The first magnetic field is in radial alignment with the shifter lever and the second magnetic field is oriented perpendicular to the first magnetic field. The first 2D magnetic sensor detects an angular displacement of the first magnetic field when the shifter lever is rotated, and the second 2D magnetic sensor detects an axial displacement of the second magnetic field relative to the pivot axis when the shifter lever is translated. 
         [0006]    In another aspect of the present invention the first 2D magnetic sensor detects an angular orientation of the first magnetic field, and the second 2D magnetic sensor detects an angular orientation of the second magnetic field. 
         [0007]    In yet another aspect of the present invention at least one of the first and second 2D magnetic sensors is an anisotropic magnetoresistance (AMR) sensor. 
         [0008]    In yet another aspect of the present invention at least one of the first and second 2D magnetic sensors is a Hall-Effect sensor. 
         [0009]    In yet another aspect of the present invention the first and the second 2D magnetic sensors are AMR sensors. 
         [0010]    In yet another aspect of the present invention the first magnet is disposed axially adjacent the second magnet. 
         [0011]    In yet another aspect of the present invention the first 2D magnetic sensor is configured to detect a rotational movement of the first magnet. 
         [0012]    In yet another aspect of the present invention the second 2D magnetic sensor is configured to detect a movement of the second magnet in an axial direction relative to the pivot axis. 
         [0013]    In yet another aspect of the present invention the first 2D magnetic sensor and the second 2D magnetic sensor are configured to detect a movement of the first magnet and the second magnet in both the rotational and the axial directions relative to the pivot axis. 
         [0014]    In yet another aspect of the present invention a shifter location system in a motor vehicle includes a shifter housing. The shifter location system further includes a shifter lever having a first end, a second end, and a flange, the shifter lever being disposed within the shifter housing and rotatably coupled to the shifter housing at the second end. The shifter lever has a pivot axis at the second end and is translationally moveable in a direction generally parallel to the pivot axis, and the flange is disposed between the first and second ends of the shifter lever. The shifter location system further includes a circuit board disposed within the shifter housing, the circuit board being disposed adjacent to the shifter lever in a plane perpendicular to the pivot axis of the shifter lever. The shifter location system further includes a first two-dimensional (2D) magnetic sensor disposed on a first side of the circuit board and in electrical communication with the circuit board. The shifter location system further includes a first magnet having a first magnetic field. The first magnet is coupled to the shifter lever between the first end and the second end, and the first magnetic field is in radial alignment with the shifter lever, and the first magnet is disposed adjacent to the first 2D magnetic sensor such that the first 2D magnetic sensor is in magnetic communication with the first magnet. The shifter location system further includes a second 2D magnetic sensor disposed on a second side of the circuit board and in electrical communication with the circuit board. The second side of the circuit board is disposed proximate to the flange. The shifter location system further includes a second magnet having a second magnetic field. The second magnet is coupled to the flange of the shifter lever, and the second magnetic field is oriented perpendicular to the first magnetic field. The second magnet is disposed adjacent to the second 2D magnetic sensor such that the second 2D magnetic sensor is in magnetic communication with the second 2D magnet. The first 2D magnetic sensor detects an angular displacement of the first magnetic field, and the second 2D magnetic sensor detects an axial displacement of the second magnetic field relative to the pivot axis. 
         [0015]    In yet another aspect of the present invention the first 2D magnetic sensor detects an angular orientation of the first magnetic field, and the second 2D magnetic sensor detects an angular orientation of the second magnetic field. 
         [0016]    In yet another aspect of the present invention at least one of the first and second 2D magnetic sensors is a Hall-Effect sensor. 
         [0017]    In yet another aspect of the present invention the first 2D magnetic sensor and the second 2D magnetic sensor are anisotropic magnetoresistance (AMR) sensors. 
         [0018]    In yet another aspect of the present invention the first magnet is disposed axially adjacent the second magnet. 
         [0019]    In yet another aspect of the present invention the first 2D sensor is configured to detect a rotational displacement of the first magnet. 
         [0020]    In yet another aspect of the present invention the second 2D sensor is configured to detect an axial displacement of the second magnet. 
         [0021]    In yet another aspect of the present invention the first 2D sensor and the second 2D sensor are configured to detect a movement of the first magnet and the second magnet in both the rotational and the axial directions. 
         [0022]    In yet another aspect of the present invention a shifter location system in a motor vehicle includes a shifter housing. The shifter location system further includes a shifter lever having a first end and a second end. The shifter lever being disposed within the shifter housing and rotatably coupled to the shifter housing at the second end. The shifter lever has a pivot axis at the second end and is translationally moveable in a direction generally perpendicular to the pivot axis. The shifter location system further includes a circuit board disposed within the housing. The shifter location system further includes a first anisotropic magnetoresistance (AMR) sensor disposed on and in electrical communication with the circuit board. The shifter location system further includes a first magnet having a first magnetic field. The first magnet is coupled to the shifter lever between the first end and the second end, the first magnetic field is oriented in radial alignment with the shifter lever, and the first magnet is disposed proximate the first AMR sensor. The shifter location system further includes a second AMR sensor disposed on and in electrical communication with the circuit board. The shifter location system further includes a second magnet having a second magnetic field. The second magnet is coupled to the shifter lever between the first end and the second end, the second magnetic field is oriented perpendicular to the first magnetic field, and the second magnet is disposed proximate the second AMR sensor, and the first AMR sensor detects an angular displacement of the first magnetic field, and the second AMR sensor detects an axial displacement of the second magnetic field. 
         [0023]    In yet another aspect of the present invention the first magnet is disposed axially adjacent the second magnet. 
         [0024]    In yet another aspect of the present invention the first AMR sensor is disposed axially adjacent to the first magnet, and the second AMR sensor is disposed radially adjacent the second magnet. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like reference numerals designate corresponding parts throughout the views. In the drawings: 
           [0026]      FIG. 1  is a perspective view of an exemplary shifter assembly for a motor vehicle having a shifter location system, according to the principles of the present invention; 
           [0027]      FIG. 2  is a perspective view of a portion of an exemplary shifter assembly for a motor vehicle having a shifter location system, according to the principles of the present invention; 
           [0028]      FIG. 3A  is an enlarged perspective view of a portion of the shifter location system of the motor vehicle, according to the principles of the present invention; 
           [0029]      FIG. 3B . is an exploded perspective view of a portion of the shifter location system for the motor vehicle, according to the principles of the present invention; and 
           [0030]      FIG. 4  is a schematic view of a portion of the shifter location system for the motor vehicle, according to the principles of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0031]    With reference to  FIGS. 1 and 2 , a shifter assembly is generally indicated by reference number  100  and is illustrated in a neutral, energized position, as will be described below. The shifter assembly  100  is employed within a motor vehicle (not shown). The shifter assembly  100  is controlled by an operator of the motor vehicle to select one of a plurality of shift positions. The shift positions may be selected by movement of the shifter assembly  100  rotationally and axially. Each of the shift positions corresponds to an operating mode of a transmission (not shown) associated with the shifter assembly  100  and the motor vehicle. For example, the shifter assembly  100  may include a park (P), reverse (R), neutral (N), and drive (D). It should be appreciated that the number of shift positions, as well as the associated transmission operating modes, may vary without departing from the scope of the present example. For example, the shifter assembly  100  may also include manual modes M, M+, and M− and/or high gear and low gear operating modes. The shifter assembly  100  may be associated with an automatic transmission or any other type of transmission including a manual transmission, continuously variable transmission, etc. 
         [0032]    The shifter assembly  100  generally includes a shifter housing  101 , a shifter lever  102 , a pivot member  104 , a first magnet  106 , a second magnet  108 , a flange  110 , a circuit board  112 , a microcontroller  114 , a plurality of electrical connectors  116 , a first sensor  118 , and a second sensor  120 . 
         [0033]    The shifter lever  102  includes a first end  122  and a second end  124 . The distance between the first end  122  and the second end  124  defines a length “L”. The first end  122  is connected to a shift knob  126  that is useable by an operator of the motor vehicle. The shifter lever  102  is pivotally mounted to the shifter housing  101  at the pivot member  104 . The pivot member  104  is generally cylindrical and has an axis of rotation “A”. In one aspect, the pivot member  104  is disposed at the second end  124  of the shifter lever  102 . In a first axial position, the shifter lever  102  rotates about the pivot member  104  in a first plane (not shown). The shifter lever  102  is translatable along the axis CA′ of the pivot member  104  to at least a second axial position that is axially spaced from the first axial position. In the second axial position, the shifter lever  102  rotates about the pivot member  104  in a second plane (not shown) parallel to the first plane. Alternatively, the pivot member  104  is rotatingly disposed within a portion of the shifter lever  102  between the first end  122  and the second end  124 . 
         [0034]    Turning now to  FIGS. 3A and 3B , and with continuing reference to  FIGS. 1 and 2 , the second magnet  108  is disposed on and supported by the flange  110 . The flange  110  has a receiver portion  132  that is configured to receive a protrusion  134  on the side portion  130  of the shifter lever  102 . In one aspect, the first magnet  106  and the flange  110  supporting the second magnet  108  are disposed on the side portion  130  of the shifter lever  102  at a position between the shift knob  126  and the pivot member  104  and/or between the pivot member  104  and the second end  124 . As shown in  FIG. 4 , the first magnet  106  has a north pole (N) and a south pole (S) and is mounted to a side portion  130  of the shifter lever  102 . Exemplary magnetic field lines between the north (N) and south (S) poles are generally indicated by the reference number  128 . 
         [0035]    The flange  110  extends perpendicularly to the first plane and the second plane and towards the circuit board  112 . The circuit board  112  is fixedly disposed in the shifter housing  101  and oriented parallel to the first plane and the second plane. While the shifter lever  102  is free to pivot within the shifter housing  101 , the circuit board  112  remains in a fixed position within the shifter housing. Thus, while the shifter lever  102  and the circuit board  112  lie in parallel planes, the shifter lever  102  moves relative to the circuit board  112 . Additionally, the circuit board  112  is in electrical communication with the microcontroller  114  via a plurality of electrical connectors  116 . 
         [0036]    The first sensor  118  is disposed on and in electrical communication with the circuit board  112  at a position that is substantially axially adjacent to the first magnet  106  on the shifter lever  102 . The first sensor  118  is an anisotropic magnetoresistance (AMR) sensor that is sensitive to the presence and angular position of a magnetic field  128 . Because AMR sensors are sensitive only to the presence and angular orientation of a magnetic field  128 , the first sensor  118  is robust. That is, the first sensor  118  is not sensitive to temperature variations, magnetic field  128  strength variations, contamination, or magnet aging effects. The first sensor  118  provides continuous position data to the microcontroller  114  via the circuit board  112 . The first sensor  118  and the first magnet  106  are in magnetic communication. 
         [0037]    The second sensor  120  is disposed on and in electrical communication with the circuit board  112  at a position that is substantially axially and/or radially adjacent to the second magnet  108 . The second sensor  120  is sensitive to the presence of a magnetic field  128 , and provides discrete position data to the microcontroller  114  via the circuit board  112 . The second magnet  108  is in magnetic communication with the second sensor  120 . Alternatively, the second sensor  120  and the second magnet  108  may be replaced with an electrical switch, a mechanical switch, an optical switch, or any other type of device that is able to detect the axial movement of the shifter lever  102 . 
         [0038]    Referring once more to  FIG. 4 , and with further reference to  FIGS. 1 and 2 , the pivoting movement of the shifter lever  102  is shown in greater detail. The shifter lever  102  pivots about the pivot member  104  in the first plane, while the circuit board  112  and first sensor  118  remain stationary relative to the shifter lever  102  and the first magnet  106 . In one aspect, a vehicle operator manipulates the shift knob  126  to move the shifter lever  102  from a first position P 1  to a second position P 2 , and/or to a third position P 3 . The second position P 2  is displaced by an angle θ from the first position P 1 , and the third position P 3  is displaced from the first position P 1  by a second angle θ′. As the position of the shifter lever  102  changes from the first position P 1  to the second or third positions P 2 , P 3 , thereby traversing the first angle or second angle θ, θ′ the angular orientation of the magnetic field  128  emitted by the first magnet  106  also changes by the same θ for the second position P 2 , and the same θ′ for the third position P 3 . Because the first sensor  118  is an AMR sensor, the first sensor  118  detects the changes in the orientation of the magnetic field  128  produced by the first magnet  106 . As the first sensor  118  detects the changes in the orientation of the magnetic field  128  produced by the first magnet  106 , the first sensor  118  electronically communicates the orientation change to the circuit board  112  which communicates the change in orientation to the microcontroller  114 . 
         [0039]    In a further example, as the vehicle operator moves the shift knob  126  axially relative to the pivot member  104 , the shifter lever  102  translates axially along the pivot member  104 . As the shifter lever  102  translates axially along the pivot member  104  relative to the stationary circuit board  112 , the flange  110  and second magnet  108  move axially relative to the stationary circuit board  112 . Additionally, the axial translation of the shifter lever  102  moves the second magnet  108  axially relative to the second sensor  120  on the stationary circuit board  112 . As the second sensor  120  detects the change in proximity of the second magnet  108  by the presence and/or strength of the magnetic field  128  produced by the second magnet  108 , the second sensor  120  electronically communicates the proximity change to the circuit board  112  which communicates the proximity change to the microcontroller  114 . The microcontroller  114  interprets the proximity change and sends an output signal to the transmission. The discrete position data generated by the second sensor  120  corresponds to at least two shifter lever  102  axial positions discussed in further detail below. 
         [0040]    The microcontroller  114  interprets changes in angular orientation and axial position of the shifter lever  102  relative to the first magnet  106  and second magnet  108 , and sends an output signal to the transmission. In one aspect, the microcontroller  114  interprets the change in angular orientation and the rate of the change in angular orientation of the shifter lever  102  as an operator-created transmission operating mode request. For example, if the first position P 1  of the shifter lever  102  corresponds to the Neutral drive mode, and the second position P 2  corresponds to the Park drive mode, then as the operator moves the shifter lever  102  from P 1  to P 2 , the microcontroller  114  interprets the angular orientation change of the shifter lever  102  as a request to alter the drive mode from Neutral to Park, and will command the transmission (not shown) to engage Park from the Neutral mode. The microcontroller  114  may determine, based on the rate of change in angular orientation of the shift lever  102 , a rate at which a transmission clutch should be engaged. The microcontroller  114  clutch engagement determination may be based on a number of additional criteria, such as current transmission operating mode, engine speed, motor vehicle speed, and noise, vibration, and harshness thresholds. 
         [0041]    Furthermore, in an aspect, the microcontroller  114  interprets the discrete position data generated by the second sensor  120  as a change in axial position of the shifter lever  102 . The change in axial position of the shifter lever  102  is an operator-created transmission operating mode request. For example, if the operator moves the shifter lever  102  axially from a position within the first plane to a position within the second plane, the microcontroller  114  may interpret the axial change as a request to alter the drive mode from an automatic mode to a manual mode. Once in the manual mode, operator inputs that alter the angular orientation of the shifter lever  102  while in the second plane are interpreted as requests for gear ratios above or below the current transmission gear ratio. In an aspect, it should be appreciated that while the shifter lever  102  is described as translating axially along the pivot member  104 , the shifter lever  102  may also rotate in a plane that is parallel to the axis of rotation ‘A’ through the pivot member  104 . 
         [0042]    With additional reference to  FIGS. 1-4 , the shifter assembly  100  creates system redundancy by using the AMR sensor and a shift-by-wire communication system between the first sensor  118  and second sensor  120 , the microcontroller  114 , and the transmission. More specifically, because the AMR is a sensitive magnetic field sensor, employing the magnetoresistance effect of thin-film permalloy, the first sensor  118  includes built-in mathematical certification checks. The sensor contains two parallel Wheatstone bridges which enclose a sensitive angle of 45 degrees. A rotating magnetic field  128  in a surface parallel to the sensor will therefore deliver to independent sinusoidal output signals, one following a sin(2θ) and the other following a cos(2θ) function, where θ is the mechanical angle between the sensor and the magnetic field  128  direction. The angular measurement θ generated by the AMR sensor provides for a first redundancy check, in which the angular measurement θ is transmitted to the microcontroller  114 . The sin 2 θ and cos 2 θ are added and if the resulting sum is equal to 1, then the microcontroller  114  certifies that the first sensor  118  measurement is accurate, and that the first sensor  118  is operating properly. 
         [0043]    For example, the operator of the motor vehicle selects a shifter lever  102  position in the first plane that corresponds to Park while the motor vehicle is moving at a high rate of speed. In the example, the AMR sensor measures the angle θ of the shifter lever  102 , and determines if the sum of the sin 2 θ and cos 2 θ is equal to 1, and if so, the microcontroller  114  certifies that the first sensor  118  measurement is accurate, and that the first sensor  118  is reporting properly. With further reference to the example, even if the angular measurement is accurate, the microcontroller  114  provides an additional redundancy and safety check by comparing the motor vehicle speed to a predetermined threshold motor vehicle speed below which the Park transmission setting may be engaged. If the motor vehicle speed has not met the threshold motor vehicle speed, the microcontroller  114  will prevent the transmission from engaging Park to avoid damage to the transmission, and unsafe operating conditions for the motor vehicle operator. Likewise, if the operator selects the manual mode by moving the shifter lever  102  axially into the second plane and then alters the angular orientation of the shifter lever  102  within the second plane to request a transmission gear ratio that is inappropriate for the current motor vehicle speed, then the microcontroller  114  will similarly nullify the operator request after performing the first redundancy check, as discussed above, and then comparing current motor vehicle speed to a predetermined threshold speed for the operator-requested gear ratio. If the predetermined threshold speed has not been met, the microcontroller  114  will ignore the operator request and prevent the transmission from engaging the operator-requested gear ratio. 
         [0044]    In one aspect, because the first sensor  118  is an AMR sensor, and the first magnet  106  is positioned between the shift knob  126  and the pivot member  104 , the length “L” of the shifter lever  102  allows the shifter assembly  100  to be compact, and the AMR sensor allows the assembly to be portable, robust, and flexible. 
         [0045]    The features and components of the present disclosure described above are merely exemplary in nature. Variations that do not depart from the gist of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.