Abstract:
Methods and systems are provided for preventing vehicle roll. In one embodiment, a method includes: determining a first switch state; determining a second switch state; evaluating the first switch state and the second switch state to determine whether a condition of a mechanical linkage between a range selection device and a transmission has occurred; and selectively generating at least one of a control signal to control an electronic park brake and a notification message based on the determination.

Description:
TECHNICAL FIELD 
       [0001]    The present disclosure generally relates to vehicles, and more particularly relates to methods and systems for controlling the vehicle to prevent vehicle movement. 
       BACKGROUND 
       [0002]    Vehicles equipped with an automatic transmission often include a shift control lever mounted on a console, the dashboard, or the steering column of the vehicle. A vehicle operator may manually move the shift control lever between shift lever positions. The shift lever positions indicate particular transmission ranges (park, reverse, neutral, drive 1, drive 2, driver 3, etc.). Movement of the shift lever into a particular shift lever position causes the transmission to be operated in a particular gear or set of gears. 
         [0003]    For example, the shift control lever includes mechanical linkages that couple to the automatic transmission. The mechanical linkages cause the automatic transmission to operate in the particular gear or set of gears. For example, when the shift control lever is moved to the park position, a mechanical linkage activates a parking pawl device or other device of the transmission. The parking pawl device locks the movement of the transmission output shaft thereby preventing movement of the vehicle wheels. 
         [0004]    In some cases, conditions can occur in one or more of the mechanical linkages that prevent proper operation. The conditions can cause unexpected movement of the vehicle. For example, when the shift control lever is in the park position and when a condition exists in the mechanical linkage between the shift control lever and the transmission, the vehicle may roll forward or backward (referred to hereinafter as vehicle roll). 
         [0005]    Accordingly, it is desirable to provide methods and systems for preventing vehicle roll. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention. 
       SUMMARY 
       [0006]    Methods and systems are provided for preventing vehicle roll. In one embodiment, a method includes: determining a first switch state; determining a second switch state; evaluating the first switch state and the second switch state to determine whether a condition of a mechanical linkage between a range selection device and a transmission has occurred; and selectively generating at least one of a control signal to control an electronic park brake and a notification message based on the determination. 
         [0007]    In another embodiment, a system includes at least two switch devices; and a control module. The control module receives switch data from the at least two switch devices, determines a first switch state based on the switch data from the first switch device, determines a second switch state based on the data from the second switch device, evaluates the first switch state and the second switch state to determine whether a condition of a mechanical linkage between a range selection device and a transmission has occurred, and selectively generates at least one of a control signal to control an electronic park brake and a notification message based on the determination. 
         [0008]    In another embodiment, a vehicle is provided. The vehicle includes an automatic transmission having a transmission mode switch, a range selection device having a park switch, an electronic park brake system having an electronic park brake, and a control module. The control module receives switch data from the transmission mode switch and the park switch, determines a first switch state based on the switch data from the transmission mode switch, determines a second switch state based on the data from the park switch, evaluates the first switch state and the second switch state to determine whether a condition of a mechanical linkage between the range selection device and the transmission has occurred, and selectively generates at least one of a control signal to control an electronic park brake and a notification message based on the determination. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0009]    The present disclosure will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and: 
           [0010]      FIG. 1  is a functional block diagram of a vehicle that includes, among other features, a vehicle roll prevention system, in accordance with exemplary embodiments; 
           [0011]      FIG. 2  is a functional block diagram of a control module of the vehicle roll prevention system in accordance with exemplary embodiments; and 
           [0012]      FIG. 3  is a flowchart of a method for preventing vehicle roll in accordance with exemplary embodiments. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    The following detailed description is merely exemplary in nature and is not intended to limit the application and uses. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. As used herein, the term module refers to any hardware, software, firmware, electronic control component, processing logic, and/or processor device, individually or in any combination, including without limitation: application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that executes one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality. 
         [0014]    With reference to  FIG. 1 , a vehicle  100  is shown that includes a vehicle roll prevention system  102  in accordance with various embodiments. Although the figures shown herein depict an example with certain arrangements of elements, additional intervening elements, devices, features, or components may be present in an actual embodiment. It should also be understood that  FIG. 1  is merely illustrative and may not be drawn to scale. 
         [0015]    As depicted in  FIG. 1 , the vehicle  100  generally includes a chassis  104 , a body  106 , front wheels  108 , rear wheels  110 , a propulsion system  112 , an electronic park brake system  113 , and at least one control module  114 . The body  106  is arranged on the chassis  104  and substantially encloses the other components of the vehicle  100 . The body  106  and the chassis  104  may jointly form a frame. The wheels  108 - 110  are each rotationally coupled to the chassis  104  near a respective corner of the body  106 . As can be appreciated, the vehicle  100  may be any one of a number of different types of automobiles, such as, for example, a sedan, a wagon, a truck, or a sport utility vehicle (SUV), and may be two-wheel drive (2WD) (i.e., rear-wheel drive or front-wheel drive), four-wheel drive (4WD) or all-wheel drive (AWD). 
         [0016]    The propulsion system  112  generally includes an engine/motor  116  and a transmission  118 . The engine/motor  116  may be any number of different types of propulsion devices, such as, for example, a gasoline or diesel fueled combustion engine, a “flex fuel vehicle” (FFV) engine (i.e., using a mixture of gasoline and ethanol), a gaseous compound (e.g., hydrogen or natural gas) fueled engine, a combustion/electric motor hybrid engine, and an electric motor. The transmission  118  may be any number of different types of automatic transmissions that automatically change the gear ratios as the vehicle  100  is moving. In various embodiments, the transmission  118  includes a transmission mode switch  120 . The transmission mode switch  120  generates mode signals. The mode signals indicate a bit encoding corresponding to states of circuits of the transmission mode switch  120 . The control module  114  receives the mode signals and interprets the mode signals as a transmission mode switch state. The control module  114  controls engine operation and transmission shift patterns based on the interpreted transmission mode switch state. 
         [0017]    The vehicle  100  further includes a range selection device  122  that is movable by a vehicle operator to a number of defined positions. Each position corresponds to a desired operating range of the transmission  118 . In various embodiments, the desired positions include a park position, a reverse position, a neutral position, and one or more forward drive positions. In various embodiments, the range selection device  122  includes a park switch  124  that communicates park switch data to the control module  114 . The control module  114  determines whether the range selection device  122  is in the park position based on the park switch state data. 
         [0018]    In some instances, mechanical linkages  126  couple the range selection device  122  directly to the transmission  118  and cause the automatic transmission  118  to operate in the intended range. For example, a mechanical linkage  126  associated with the park position of the range selection device  122  causes the transmission  118  to operate in a park range. 
         [0019]    In some instances, a condition may occur in the mechanical linkage  126  causing the transmission  118  to not operate in the intended range. For example, one or more cables and/or solid linkages of the mechanical linkage  126  can become detached from the interfaces at the transmission  118  and/or the range selection device  122 . In another example, one or more cable core wires can fracture from corrosion and/or cyclic operation. As can be appreciated, other conditions may occur in the mechanical linkage  126 , in various embodiments, causing the transmission to not operate in the intended range, as the disclosure is not limited to the present examples. 
         [0020]    The control module  114  identifies the condition of the mechanical linkage  126  between the range selection device  122  and the transmission  118  and generates messages indicating the condition and/or controls the electronic park brake system  113  such that a vehicle roll does not occur. In general, the control module  114  monitors the state of the park switch  124  of the range selection device  122  and the switch state of the transmission mode switch  120  and identifies a condition in the mechanical linkage  126  based on a comparison of the two switch states. When the park switch state indicates a park position and the transmission mode switch state indicates a non-park position (e.g., neutral, reverse, drive 1, drive 2, drive 3, etc.), a condition is identified and a message is generated and/or the electronic park brake system  113  (if present on the vehicle  100 ) is controlled such that an electronic park brake is applied. Applying the electronic park brake prevents vehicle roll. 
         [0021]    Referring now to  FIG. 2  and with continued reference to  FIG. 1 , a dataflow diagram illustrates the control module  114  of  FIG. 1  in accordance with various embodiments. As can be appreciated, various embodiments of the control module  114 , according to the present disclosure, may include any number of sub-modules. For example, the sub-modules shown in  FIG. 2  may be combined and/or further partitioned to similarly prevent a vehicle roll condition. As discussed above, inputs to the control module  114  may be received from sensors or switches, received from other control modules (not shown) within the vehicle  100 , and/or determined by sub-modules (not shown) within the control module  114 . In various embodiments, the control module  114  includes a park switch state determination module  130 , a transmission mode switch state determination module  132 , and an electronic park brake control module  134 . 
         [0022]    The park switch state determination module  130  receives as input data  136  from the park switch  124 . The data  136  is evaluated to determine a park switch state  138 . In various embodiments, the park switch state determination module  130  determines the park switch state  138  to be at least one of PARK, meaning the range selection device  122  is in the park position, and OTHER meaning the range selection device  122  is in a position other than the park position. 
         [0023]    The transmission mode switch state determination module  132  receives as input data  140  from the transmission mode switch  120 . The data  140  is evaluated to determine a transmission mode switch state  142 . In various embodiments, the transmission mode switch state determination module  132  determines the transmission mode switch state  142  to be at least one of PARK meaning the range selection device  122  is in the park position, REVERSE meaning the range selection device  122  is in a reverse position, NEUTRAL meaning the range selection device  122  is in a neutral position, DRIVE 1 meaning the range selection device  122  is in a drive position, and any other values indicating a position of the range selection device  122 . 
         [0024]    The electronic park brake control module  134  receives as input the park switch state  138  and the transmission mode switch state  142 . The electronic park brake control module  134  evaluates the park switch state  138  and the transmission mode switch state  142  to determine whether a condition has occurred in the mechanical linkage  126  between the range selection device  122  and the transmission  118 . For example, the electronic park brake control module  134  compares the park switch state  138  to the transmission mode switch state  142 . When the park switch state  138  indicates OTHER, the electronic park brake control module  134  determines that a condition cannot be determined and no control signals and/or message are generated. 
         [0025]    When the park switch state  138  indicates PARK and the transmission mode switch state  142  indicates a state other than PARK, the electronic park brake control module  134  determines a condition and generates a control signal  146  to the electronic park brake system  113  and/or a message  144  that is communicated on a communication bus (not shown) to the electronic park brake system  133  indicating to activate the electronic park brake. 
         [0026]    With reference now to  FIG. 3 , a flowchart is shown of a method  200  for preventing vehicle roll, in accordance with exemplary embodiments. The method  200  can be utilized in connection with the vehicle  100  of  FIG. 1  and can be performed by control module of  FIG. 2 , in accordance with exemplary embodiments. As can be appreciated in light of the disclosure, the order of operation within the method is not limited to the sequential execution as illustrated in  FIG. 3 , but may be performed in one or more varying orders as applicable and in accordance with the present disclosure. As can further be appreciated, the method of  FIG. 3  may be scheduled to run at predetermined time intervals during operation of the vehicle  100  and/or may be scheduled to run based on predetermined events. 
         [0027]    As depicted in  FIG. 3 , the method may begin at  205 . The park switch data  136  is received and the park switch state  138  is determined  210 . The transmission mode switch data  140  is received and the transmission mode switch state  142  is determined at  220 . 
         [0028]    The park switch state  138  and the transmission mode switch state  142  are evaluated at  230 - 250 . For example, if the park switch state  138  and the transmission mode switch state  142  do not indicate PARK at  230 , the method continues at  205 . If, however, at least one of the park switch state  138  and the transmission mode switch state  142  indicates PARK at  230 , the method continues at  240 . 
         [0029]    At  240 , if the park switch state  138  does not indicate PARK at  240 , the method continues at  205 . If, however, the park switch state  138  does indicate PARK at  240 , and the transmission mode switch state  142  indicates PARK at  250 , the method continues at  205 . If however, the park switch state  138  does indicate PARK, and the transmission mode switch does not indicate PARK at  250 , it is determined that a condition in the mechanical linkage exists at  260 . One or more control signals  146  and/or messages  144  are generated to indicate a condition exists and/or to control the electronic park brake system  133  at  270 . Thereafter, the method may end at  280 . 
         [0030]    As can be appreciated, the disclosed methods and systems may vary from those depicted in the Figures and described herein. For example, as mentioned above, the vehicle  100  of  FIG. 1 , and the control module  114  of  FIGS. 1 and 2 , and/or portions and/or components thereof may vary, and/or may be disposed in whole or in part in any one or more of a number of different vehicle units, devices, and/or systems, in certain embodiments. In addition, it will be appreciated that certain steps of the method  200  may vary from those depicted in  FIG. 3  and/or described above in connection therewith. It will similarly be appreciated that certain steps of the method  200  may occur simultaneously or in a different order than that depicted in  FIG. 3  and/or described above in connection therewith. 
         [0031]    While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the invention as set forth in the appended claims and the legal equivalents thereof.