Abstract:
A system includes a pedal override module that receives a pedal position from an accelerator pedal position sensor, receives a pedal pressure from an accelerator pedal pressure sensor, compares the pedal position to the pedal pressure, and selectively outputs a pedal override signal based on the comparison between the pedal position and the pedal pressure. A throttle position control module controls a position of a throttle based on the pedal position and the pedal override signal.

Description:
FIELD 
       [0001]    The present disclosure relates to throttle control in a vehicle, and more particularly to throttle control using an accelerator pedal position sensor and an accelerator pedal pressure sensor. 
       BACKGROUND 
       [0002]    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. 
         [0003]    A driver controls engine and vehicle speed in a vehicle driven by internal combustion engine, a hybrid, and/or an electric vehicle using an actuator such as an accelerator pedal. For example, the driver applies pressure to the accelerator pedal to actuate a throttle. A pedal position sensor determines a position of the accelerator pedal and controls a throttle position based on the pedal position and various other factors. The resultant throttle position determines speed and acceleration of the vehicle. 
       SUMMARY 
       [0004]    A system includes a pedal override module that receives a pedal position from an accelerator pedal position sensor, receives a pedal pressure from an accelerator pedal pressure sensor, compares the pedal position to the pedal pressure, and selectively outputs a pedal override signal based on the comparison between the pedal position and the pedal pressure. A throttle position control module controls a position of a throttle based on the pedal position and the pedal override signal. 
         [0005]    In other features, a method includes receiving a pedal position from an accelerator pedal position sensor, receiving a pedal pressure from an accelerator pedal pressure sensor, comparing the pedal position to the pedal pressure, selectively outputting a pedal override signal based on the comparison between the pedal position and the pedal pressure, and controlling a position of a throttle based on the pedal position and the pedal override signal. 
         [0006]    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 
         [0007]    The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein: 
           [0008]      FIG. 1  is a functional block diagram of a vehicle including an accelerator pedal pressure sensor according to the present disclosure; 
           [0009]      FIG. 2  is a schematic illustration of an accelerator pedal assembly according to the present disclosure; 
           [0010]      FIG. 3  is a functional block diagram of the accelerator pedal assembly and a control module according to the present disclosure; and 
           [0011]      FIG. 4  is a flow diagram illustrating an accelerator pedal pressure sensing method according to the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    The following description is merely illustrative 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. 
         [0013]    As used herein, the term module may refer to, be part of, or include an Application Specific Integrated Circuit (ASIC); an electronic circuit; a combinational logic circuit; a field programmable gate array (FPGA); a processor (shared, dedicated, or group) that executes code; other suitable components that provide the described functionality; or a combination of some or all of the above, such as in a system-on-chip. The term module may include memory (shared, dedicated, or group) that stores code executed by the processor. 
         [0014]    The term code, as used above, may include software, firmware, and/or microcode, and may refer to programs, routines, functions, classes, and/or objects. The term shared, as used above, means that some or all code from multiple modules may be executed using a single (shared) processor. In addition, some or all code from multiple modules may be stored by a single (shared) memory. The term group, as used above, means that some or all code from a single module may be executed using a group of processors or a group of execution engines. For example, multiple cores and/or multiple threads of a processor may be considered to be execution engines. In various implementations, execution engines may be grouped across a processor, across multiple processors, and across processors in multiple locations, such as multiple servers in a parallel processing arrangement. In addition, some or all code from a single module may be stored using a group of memories. 
         [0015]    The apparatuses and methods described herein may be implemented by one or more computer programs executed by one or more processors. The computer programs include processor-executable instructions that are stored on a non-transitory tangible computer readable medium. The computer programs may also include stored data. Non-limiting examples of the non-transitory tangible computer readable medium are nonvolatile memory, magnetic storage, and optical storage. 
         [0016]    A pedal position sensor is arranged to sense a pedal position of an accelerator pedal in a vehicle. Accordingly, the pedal position sensor may be indicative of driver intent with respect to speed and/or acceleration of the vehicle. A vehicle according to the present disclosure includes a pedal pressure sensor in addition to the pedal position sensor to provide a further indicator of driver intent. 
         [0017]    Referring now to  FIG. 1 , a vehicle  100  includes an engine  104 . The engine  104  combusts an air and fuel mixture within cylinders (not shown) to produce drive torque. Air is drawn into the engine  104  through a throttle  108 . A torque converter  112  transfers and multiplies torque from the engine  104  and provides the torque to a transmission  116 . The transmission  116  operates in one or more gear ratios to transfer the torque to a driveline  120 . Although the vehicle  100  including an internal combustion engine is described, it is to be understood that the principles of the present disclosure may also be applied to a vehicle including a hybrid powertrain and/or an electric vehicle. 
         [0018]    An accelerator pedal assembly  124  enables a driver of the vehicle  100  to adjust the position of the throttle  108  to achieve a desired speed. The accelerator pedal assembly includes an accelerator pedal  128 , an accelerator pedal position sensor  132 , and an accelerator pedal pressure sensor  136 . The accelerator pedal position sensor  132  generates a pedal position signal indicating a position of the accelerator pedal  128 . The accelerator pedal pressure sensor  136  generates a pedal pressure signal indicating an amount of pressure applied to the accelerator pedal  128  by a driver. A control module  140  receives the pedal position signal and the pedal pressure signal and adjusts the position of the throttle  108  accordingly, which adjusts airflow into the engine  104 . The control module  140  adjusts fuel delivery to the engine  104  based on the airflow. 
         [0019]    Referring now to  FIG. 2 , the accelerator pedal assembly  124  is shown to include the accelerator pedal  128 , the accelerator pedal position sensor  132 , the accelerator pedal pressure sensor  136 , and an accelerator pedal arm  160 . When the accelerator pedal  128  is actuated (e.g., when the driver depresses the accelerator pedal  128 ), the accelerator pedal arm  160  changes position accordingly. The accelerator pedal position sensor  132  senses the position of the accelerator pedal  128  and/or the accelerator pedal arm  160  and generates the pedal position signal accordingly. 
         [0020]    For example only, the accelerator pedal position sensor  132  includes a rotational sensor that senses a rotational position of the accelerator pedal arm  160 . The accelerator pedal position sensor  132  generates the pedal position signal indicative of the position of the accelerator pedal  128  regardless of whether pressure is actually applied to the accelerator pedal  128 . In other words, the accelerator pedal position sensor  132  generates the pedal position signal independently of pressure sensed by the accelerator pedal pressure sensor  136 . 
         [0021]    The accelerator pedal pressure sensor  136  is arranged on a contact surface (e.g., a foot plate)  164  of the accelerator pedal  128 . Although only a single accelerator pedal pressure sensor  136  is shown, it is to be understood that multiple pressure sensors may be provided. For example, multiple pressure sensors may be provided to sense the pressure applied to the accelerator pedal  128  regardless of where the driver contacts the contact surface  164 . 
         [0022]    The accelerator pedal pressure sensor  136  senses pressure applied to the contact surface  164  of the accelerator pedal  128  and generates the pedal pressure signal accordingly. The accelerator pedal pressure sensor  136  generates the pedal pressure signal indicative of the pressure applied to the accelerator pedal  128  regardless of the position of the accelerator pedal  128  and the corresponding pedal position signal. In other words, the accelerator pedal pressure sensor  136  generates the pedal pressure signal independently of the position sensed by the accelerator pedal position sensor  132 . For example, if the driver is not applying pressure to the accelerator pedal  128  but the accelerator pedal is in a depressed position, the accelerator pedal pressure sensor  136  continues to indicate via the pedal pressure signal that no pressure is applied to the accelerator pedal  128 . Accordingly, the accelerator pedal pressure sensor  136  accurately indicates driver intent notwithstanding the position sensed by the accelerator pedal position sensor  132 . 
         [0023]    Referring now to  FIG. 3 , the control module  140  includes a pedal position determination module  200 , a pedal pressure determination module  204 , a pedal sensor diagnostic module  208 , and an accelerator pedal override module  212 . The pedal position determination module  200  receives the pedal position signal from the accelerator pedal position sensor  132  and determines a pedal position accordingly. The pedal position determination module  200  provides the pedal position to the accelerator pedal override module  212 . The pedal pressure determination module  204  receives the pedal pressure signal from the accelerator pedal pressure sensor  136  and determines a pedal pressure accordingly. The pedal pressure determination module  204  provides the pedal pressure to the pedal override module  212 . 
         [0024]    The pedal sensor diagnostic module  208  receives the pedal position signal, the pedal pressure signal, and one or more other signals  220 . The pedal sensor diagnostic module  208  performs diagnostics on the accelerator pedal position sensor  132  and the accelerator pedal pressure sensor  136  based on the pedal position signal, the pedal pressure signal, and the signals  220 . For example, the pedal sensor diagnostic module  208  determines whether the pedal position signal and/or the pedal pressure signal are valid. For example only, the pedal position signal or the pedal pressure signal may not be valid due to a faulty accelerator pedal position sensor  132  or accelerator pedal pressure sensor  136 , respectively. Alternatively, the pedal position signal or the pedal pressure signal may not be valid due to other factors interfering with the pedal position signal or the pedal pressure signal. For example, the pedal sensor diagnostic module  208  may detect electrical shorts to power or ground and/or an open circuit associated with the sensors  132  and  136  or other relevant circuitry. The pedal sensor diagnostic module  208  generates one or more sensor diagnostic signals indicating whether the pedal position signal and/or the pedal pressure signal are valid and provides the sensor diagnostic signals to the pedal override module  212 . 
         [0025]    The pedal override module  212  determines whether to override the pedal position based on the pedal position, the pedal pressure, and the sensor diagnostic signals. For example, a throttle position control module  228  may generally provide a throttle position control signal to the throttle  108  based on the pedal position. Accordingly, the throttle position control module  228  controls a position of the throttle  108 . However, the pedal override module  212  may output a pedal position override signal to the throttle position control module  228  based on the pedal position, the pedal pressure, and the sensor diagnostic signals. 
         [0026]    For example, the pedal override module  212  may output the pedal position override signal if the sensor diagnostic signals indicate that the pedal position and/or pedal pressure are not valid. Further, the pedal override module  212  may compare the pedal position and the pedal pressure and output the pedal position override signal if the pedal position and the pedal pressure provide contradictory indications of driver intent. For example only, if the pedal position indicates a high pedal position (e.g., a position greater than or equal to a pedal position threshold, where a high pedal position indicates a high rotational degree of actuation of the accelerator pedal  128 ) but the pedal pressure indicates low pressure on the accelerator pedal  128  (e.g., a pressure less than a pedal pressure threshold), then the pedal position and the pedal pressure may indicate contradictory indications of driver intent. In other words, in this situation, the accelerator pedal  128  may be in a depressed position without any pressure applied by the driver, and therefore without driver intent. 
         [0027]    The pedal position and the pedal pressure may also provide contradictory indications of driver intent if the pedal pressure is not within a predetermined range of the pedal position. For example, the pedal pressure may be indexed to a corresponding pedal position. If the pedal position corresponding to the pedal pressure is not within the predetermined range of the sensed pedal position, the pedal override module  212  may output the pedal position override signal. Those skilled in the art can appreciate that other methods of analyzing the pedal position and the pedal pressure to determine whether the pedal position accurately indicates driver intent are anticipated. 
         [0028]    Accordingly, the throttle position control module  228  may disregard the pedal position in response to the pedal position override signal. For example, the throttle position control module  228  may temporarily control the throttle  108  based on other signals, or may limit the performance capabilities of the vehicle until the vehicle is serviced. For example only, a positional range of the throttle  108  may be limited to a percentage of the entire range (e.g., 0-8 percent of the entire range), which limits engine torque. The control module  140  may take remedial actions to stop the vehicle, and/or provide information to the driver (e.g., via a check engine light) that a fault has occurred and the vehicle should be serviced. For example only, the vehicle  100  may include a second accelerator pedal position sensor (not shown) to provide redundancy in case the accelerator pedal position sensor  132  is faulty. 
         [0029]    Referring now to  FIG. 4 , an accelerator pedal pressure sensing method  300  begins at  304 . At  308 , the method determines whether the pedal position is valid. If true, the method  300  continues to  312 . If false, the method  300  continues to  316 . At  312 , the method  300  determines whether the pedal pressure is valid. If true, the method  300  continues to  320 . If false, the method  300  continues to  316 . At  320 , the method  300  determines whether the pedal position and the pedal pressure provide contradictory indications of driver intent. If true, the method  300  continues to  316 . If false, the method  300  continues to  324 . At  324 , the method  300  controls throttle position according to pedal position. At  316 , the method  300  generates a pedal position override signal and/or takes other remedial actions. The method  300  ends at  328 . 
         [0030]    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.