Abstract:
A system comprises a shifter module, an engine control module, and a transmission control module. The shifter module generates a position signal based on a position of a driver input. The engine control module controls an engine, selects one of a plurality of transmission gear ranges based on a mapping of the position signal to the plurality of transmission gear ranges, and generates a range request signal based on the selected transmission gear range. The transmission control module controls a transmission based on the range request signal.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/058,315, filed on Jun. 3, 2008. The disclosure of the above application is incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The present disclosure relates to electronic transmission control and more particularly to range selection. 
       BACKGROUND 
       [0003]    The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure. 
         [0004]    Referring now to  FIG. 1 , a functional block diagram of electronic transmission range selection is presented. Range selection is the act of selecting a gear range such as park, reverse, neutral, drive, low, or overdrive in a vehicle  100 . The vehicle  100  includes a shifter module  112 . The shifter module  112  is used by a driver to select a range. 
         [0005]    The shifter module  112  may determine the position of a driver input by using sensors. The driver input may include, for example, a lever, button, or paddle. Readings from the sensors may be transmitted to a shifter interpretation module (SIM)  110 . The SIM  110  may then interpret the sensor readings, determine which range the driver has selected, and transmit a range request to an engine control module (ECM)  104  and a transmission control module (TCM)  106 . 
         [0006]    The engine control module  104  controls an engine  102 . The engine control module  104  may use data from the engine  102  to control components of the vehicle  100 . The TCM  106  may receive the range request in different ways. For example, the TCM  106  may receive the range request by direct connection or via a network. The TCM  106  uses the range request to control a transmission  108 . 
       SUMMARY 
       [0007]    A system includes a shifter module, an engine control module, and a transmission control module. The shifter module generates a position signal based on a position of a driver input. The engine control module controls an engine, selects one of a plurality of transmission gear ranges based on a mapping of the position signal to the plurality of transmission gear ranges, and generates a range request signal based on the selected transmission gear range. The transmission control module controls a transmission based on the range request signal. 
         [0008]    In further features, the driver input includes a lever, and the position signal is based on a position of said lever. In still further features, the position of the lever is based on an angle of the lever. In other features, the shifter module comprises a driver input, a sensor, an encoding module, and a transmitting module. The sensor generates a first signal based on the position of the driver input. The encoding module encodes the first signal to generate the position signal. The transmitting module transmits the position signal to the engine control module. 
         [0009]    In still other features, the engine control module comprises a receiving module, a decoding module, and an interpretation module. The receiving module receives the position signal. The decoding module decodes the received position signal. The interpretation module selects the selected transmission gear range and generates the range request signal. In other features, the engine control module controls the transmission when the transmission control module is malfunctioning. 
         [0010]    In still other features, the system further comprises a backup transmission control module that controls the transmission when the transmission control module is malfunctioning. In other features, the engine control module generates a status signal based on the range request signal and a status of the transmission control module. In further features, the system further comprises a driver information center that selectively produces at least one of a visual indicator and an auditory indicator based on the status signal. 
         [0011]    A method comprises generating a position signal using a shifter module based on a position of a driver input; controlling an engine using an engine control module; selecting one of a plurality of transmission gear ranges using the engine control module based on a mapping of the position signal to the plurality of transmission gear ranges; generating a range request signal using the engine control module based on the selected transmission gear range; and controlling a transmission based on the range request signal. 
         [0012]    In further features, the driver input includes a lever, and the position signal is based on a position of the lever. In still further features, the position of the lever is based on an angle of the lever. In other features, the method further comprises generating a first signal using the shifter module based on the position of the driver input; encoding the first signal using the shifter module; generating the position signal using the shifter module based on the encoding; and transmitting the position signal to the engine control module. 
         [0013]    In still other features, the method further comprises receiving the position signal using the engine control module; decoding the received position signal using the engine control module; and selecting the selected transmission gear range using the engine control module based on the decoding. In other features, the method further comprises controlling the transmission using the engine control module based on a status of a transmission control module. In further features, the method further comprises controlling the transmission using the engine control module when the transmission control module is malfunctioning. 
         [0014]    In other features, the method further comprises controlling the transmission using a backup transmission control module based on a status of a transmission control module. In further features, the method further comprises controlling the transmission using the backup transmission control module when the transmission control module is malfunctioning. In still other features, the method further comprises generating a status signal using the engine control module based on the range request signal and a status of a transmission control module. In further features, the method further comprises selectively producing at least one of a visual indicator and an auditory indicator using a driver information center based on the status signal. 
         [0015]    Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein: 
           [0017]      FIG. 1  is a functional block diagram of an electronic transmission range selection system according to the prior art; 
           [0018]      FIG. 2  is a functional block diagram of an exemplary electronic transmission range selection system according to the principles of the present disclosure; and 
           [0019]      FIG. 3  is a flowchart that depicts exemplary steps performed in range selection based on connecting the shifter module to the ECM according to the principles of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    The following description is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A or B or C), using a non-exclusive logical or. It should be understood that steps within a method may be executed in different order without altering the principles of the present disclosure. 
         [0021]    As used herein, the term module refers to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality. 
         [0022]    Electronic transmission range selection is used in a vehicle to enable a user of the vehicle to select a gear range, such as park, neutral, reverse, drive, low, and overdrive. A shifter module detects actuation of a driver input. An engine control module translates the actuation into a range request. For example, actuation of a lever may be detected by the shifter module. The position of the lever is sent to the engine control module where it is translated into a range request. The engine control module transmits the range request to a transmission control module that controls a transmission based on the range request. Previously, a shifter interpretation module translated the actuation of the driver input into a range request. The shifter interpretation module also transmitted the range request to the transmission. 
         [0023]    In the present disclosure, the shifter interpretation module has been eliminated from the system and its functionality incorporated in the engine control module. By doing this, the system may become more reliable because it reduces the number of components that may fail within the system. Also, it may reduce vehicle cost because the shifter interpretation module is not used. 
         [0024]    Referring now to  FIG. 2 , a functional block diagram of an exemplary electronic transmission range selection system according to the principle of the present disclosure is shown. Electronic transmission range selection may be performed by connecting a shifter module  202  directly to an engine control module (ECM)  204  as shown in  FIG. 2 . In various implementations, the shifter module  202  may be directly connected to the ECM  204 , such as via a network, cabling, or wirelessly. For example only, the connection may be made with a network such as a controller area network (CAN) or local interconnect network (LIN). 
         [0025]    The shifter module  202  includes a driver input  206  that may include a lever, button, or paddle. The driver input  206  may be used by a driver to select a gear range, such as park, reverse, neutral, drive, low, or overdrive. The shifter module  202  may also include a sensor  208 , an encoding module  210 , and a transmitting module  209 . 
         [0026]    The sensor  208  may be used to detect use of the driver input  206 . For example, the driver input  206  may include a lever and the sensor  208  may measure an angle of the lever. The output from the sensor  208  may be transmitted to the encoding module  210  which may be located within the shifter module  202 . 
         [0027]    The encoding module  210  may encode the output from the sensor  208 . The encoding module  210  may then transmit an encoded signal to the transmitting module  209 . The transmitting module  209  receives the signal from the encoding module  210  and relays the signal to the ECM  204  or, more particularly, to a receiving module  211  that may be located within the ECM  204 . The signal is received by the receiving module  211 . The receiving module  211  may then transmit the signal to a decoding module  212  where the signal is decoded. The decoded signal is then transmitted to an interpretation module  214 . The interpretation module  214  may read, diagnose, and interpret the decoded signal to determine the range request. 
         [0028]    There are various methods to encode, decode, and interpret the signals, such as with software or hardware. For example, single edge nibble transmission (SENT) may be used to encode the sensor signal. SENT is a method that uses analog to digital converters and pulse width modulation techniques as an alternative to digital buses. The encoded signal may then be diagnosed and interpreted within the ECM  204 . The interpretation module  214  transmits the range request to a transmission control module (TCM)  216 , a monitoring module  217 , and a backup TCM module  222 . 
         [0029]    The TCM  216  controls a transmission  219  based on the range request. Both the TCM  216  and the monitoring module  217  may transmit the range request to a body control module (BCM)  218  to be displayed in a driver information center (DIC)  220 . This is done by the monitoring module  217  as a backup in cases where a component may not be functioning properly. For example, if the TCM  216  is not functioning properly, the system may continue operating because the requested range is still known by the monitoring module  217 . 
         [0030]    The monitoring module  217  monitors the range request as well as status signals from vehicle components. For example, an engine  213  may include engine sensors, such as a revolutions per minute (RPM) sensor  215 , that the monitoring module  217  monitors. The TCM  216  may also be monitored. If the TCM  216  in working order, then the monitoring module  217  may transmit the range request to the body control module  218 . If the TCM  216  is not functioning properly, then the ECM  204  may enter limp home mode. 
         [0031]    In limp home mode, the vehicle may be driven until the engine is turned off. For example only, the range request may be used by another controller, such as the ECM  204  or the backup TCM module  222 , to control the transmission in case of a failure by the TCM  216 . For example, the backup TCM module  222  may control other functions in the vehicle and when the TCM  216  fails, it may receive the range request and control the transmission  219 . In various implementations, the functionality of the backup TCM module  222  may be incorporated within the ECM  204 . 
         [0032]    When the vehicle is in limp home mode, the monitoring module  217  may transmit a message signal to the body control module  218  to be displayed in the DIC  220 . The DIC  220  may notify the driver that the vehicle is in limp home mode. After the engine is turned off, the vehicle may not be driven until the TCM  216  is functioning properly or replaced. 
         [0033]    If the ECM  204  is not functioning, the system may still be secure. For example, if the driver attempts to start the car when the ECM  204  is not functioning properly, the engine may be unable to turn on. The transmission  219  may rely on hydraulic pressure to shift and may be unable to shift out of park because the engine is not running. If the engine is running when the ECM  204  fails, the engine may immediately shut down, causing the transmission  219  to revert to park. 
         [0034]    Referring now to  FIG. 3 , a flowchart depicts exemplary steps performed in range selection based on connecting a shifter module to the ECM. Control begins in step  300 , where the position of the driver input is determined. For example only, the position may be the position of a lever or an actuation of a button or paddle. Control then transfers to step  302 , where the current position is compared to the previous position. If it is different, then control transfers to step  304 ; otherwise, control returns to step  300 . 
         [0035]    At step  304 , the new position is encoded for transmission to the engine control module. Control then transfers to step  306 , where the new position is transmitted to the engine control module. The next step is  308 , where a determination of the engine control module&#39;s functionality is made. If the ECM is functioning, then control transfers to step  310 ; otherwise, control transfers to step  328 . At step  328 , the engine is turned off. After step  328 , control transfers to step  330 , where the transmission reverts to park. 
         [0036]    At step  310 , the new position is decoded. The decoded signal is then translated to a range request at step  312 . Then control transfers to step  314 , where the status of the TCM is received. Control then transfers to step  316 , where the TCM is checked to determine if it is functioning properly. If the TCM is functioning properly, control transfers to step  318 ; otherwise, control transfers to steps  317 . At step  318 , the TCM adjusts the transmission according to the range request. Control then transfers back to step  300 . 
         [0037]    If the TCM is not functioning properly at step  316 , control transfers to step  317 , where a backup controller, such as the ECM, takes over control of the transmission. Control then transfers to step  320 , where the status and/or error of the TCM is transmitted to the BCM. The next step is  322 , where the DIC indicates the status and/or error. Control then transfers to step  324 , where a check is made to determine if the engine is running. If it is running, the next step is  326 , where control waits for the driver to select park; otherwise, control transfers to step  330  and the transmission reverts to park. After step  326 , the engine is turned off at step  328 . After step  328 , control continues to step  330  and the transmission reverts to park. 
         [0038]    Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, the specification, and the following claims.