Abstract:
A system for overriding a vehicle speed limit setting via accelerator pedal override is disclosed, comprising a vehicle including steering, an accelerator pedal, brakes, a processor, and memory, and a vehicle speed limit override module coupled to the processor and configured to override the speed limit setting by calculating an override threshold based on the set speed limit and accounting for variable vehicle weight, road grade or other unknown loads.

Description:
BACKGROUND 
       [0001]    This application relates generally to the field vehicle acceleration management systems, and more particularly to accelerator pedal override systems. 
         [0002]    Automobiles may be made available with convenience functions similar to cruise control, known as driver adjustable vehicle speed limiting (VSL) functions. These functions are known by their marketing names as Adjustable Speed Limiter (ASL or ASLD) and Intelligent Speed Limiter (ISL). The purpose of these functions is to allow the driver to set a desired vehicle speed limit when they are driving. ASL and ISL are similar to cruise control with the main difference being the driver is setting a vehicle speed limit rather than a set speed. The driver can then drive normally with confidence that the vehicle will not inadvertently exceed the desired speed limit. This is particularly useful in areas where roadway speed limits are strictly enforced. 
         [0003]    Ordinarily, once the vehicle speed reaches the speed limit, the ASL ignores further increases in the accelerator pedal position by the driver to maintain the set speed limit. The driver may nevertheless expect that if they press the accelerator pedal far enough, they will be able to override and exceed the desired speed limit. Such override mechanisms present several challenges, including an undesirable surge in vehicle acceleration once the override mechanism engages, undesirable dead pedal feel during pedal override, and undesirable vehicle performance characteristics during transition back to the vehicle set speed limit. 
         [0004]    There exists a need, therefore, for an accelerator pedal override system which solves these problems. 
       SUMMARY 
       [0005]    An embodiment of a system for overriding a vehicle speed limit setting via accelerator pedal override is disclosed, comprising a vehicle including steering, an accelerator pedal, brakes, a processor, and memory, and a vehicle speed limit override module coupled to the processor and configured to override the speed limit setting by calculating an override threshold based on the set speed limit and accounting for variable vehicle weight, road grade or other unknown loads. 
         [0006]    The vehicle speed limit override module may be configured to receive pedal position data. The pedal position data may include pedal override position data associated with initiation of pedal override based on the set speed limit and vehicle load conditions. The vehicle speed limit override module may be configured to provide feedback to a driver to indicate that pedal override has occurred. The feedback may include a desired vehicle acceleration offset from a current vehicle acceleration to enable a driver to feel when pedal override is triggered. The vehicle speed limit override module may be configured to exit pedal override when a pedal override acceleration request associated with an increasing pedal position becomes greater than a driver demand acceleration request. The vehicle speed limit override module may be configured to exit pedal override when a pedal override acceleration request associated with a decreasing pedal position becomes less than a pedal override trigger point and greater than a driver demand acceleration request. 
         [0007]    In another embodiment, a system for overriding a vehicle speed limit setting via accelerator pedal override is disclosed, comprising a vehicle including steering, an accelerator pedal, brakes, a processor, and memory, and a vehicle speed limit override module coupled to the processor and configured to rescale a pedal override position to 50% of a total available rescaled pedal travel after initiation of pedal override of the speed limit setting to compensate accelerator pedal travel range. 
         [0008]    The vehicle speed limit override module may be configured to receive pedal position data from a pedal position sensor. The pedal position data may include pedal override position data associated with initiation of pedal override based on the set speed limit and vehicle load conditions. The vehicle speed limit override module may be configured to provide feedback to a driver to indicate that pedal override has occurred. The feedback may include a desired vehicle acceleration offset from a current vehicle speed that provides a relatively smooth transition from speed limiting to vehicle acceleration due to initiation of pedal override. The vehicle speed limit override module may be configured to exit pedal override when a pedal override acceleration request associated with an increasing pedal position becomes greater than a driver demand acceleration request. The vehicle speed limit override module may be configured to exit pedal override when a pedal override acceleration request associated with a decreasing pedal position becomes less than a pedal override trigger point and greater than a driver demand acceleration request. 
         [0009]    In another embodiment, a system for overriding a vehicle speed limit setting via accelerator pedal override is disclosed, comprising a vehicle including steering, an accelerator pedal, brakes, a processor, and memory, and a vehicle speed limit override module coupled to the processor and configured to rescale a pedal override position to 50% of a total available rescaled pedal travel after initiation of pedal override of the speed limit setting to compensate accelerator pedal travel range, wherein vehicle acceleration smoothly transitions from speed limiting to vehicle acceleration after initiation of pedal override. 
         [0010]    The vehicle speed limit override module may be configured to receive pedal position data from a pedal position sensor. The pedal position data may include pedal override position data associated with initiation of pedal override based on the set speed limit and vehicle load conditions. On a tip-out of the pedal while in override, the vehicle speed limit override module may be configured to cause an increase in acceleration of the vehicle to return on subsequent tip-in of the pedal. The vehicle speed limit override module may be configured to exit pedal override when a pedal override acceleration request associated with an increasing pedal position becomes greater than a driver demand acceleration request. The vehicle speed limit override module may be configured to exit pedal override when a pedal override acceleration request associated with a decreasing pedal position becomes less than a pedal override trigger point and greater than a driver demand acceleration request. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1A  illustrates a top view of a vehicle of the instant disclosure. 
           [0012]      FIG. 1B  illustrates a rear view of the vehicle shown in  FIG. 1A . 
           [0013]      FIG. 2  illustrates a block diagram of exemplary components of the vehicle shown in  FIG. 1A . 
           [0014]      FIG. 3  illustrates a block diagram of an exemplary computing device operatively connected to the vehicle shown in  FIG. 1A . 
           [0015]      FIG. 4  illustrates an exemplary effect of rescaling pedal override position of the instant disclosure. 
           [0016]      FIG. 5  illustrates an exemplary effect of rescaling pedal override position of the instant disclosure. 
           [0017]      FIG. 6  illustrates an exemplary plot of pedal override acceleration request as a function of scaled pedal position. 
           [0018]      FIG. 7  illustrates an exemplary plot of acceleration request as a function of pedal position showing the transition from speed limiting to pedal override. 
           [0019]      FIG. 8  illustrates an exemplary plot of acceleration request as a function of scaled pedal position showing the transition from speed limiting to pedal override. 
           [0020]      FIG. 9  illustrates an exemplary plot of acceleration request as a function of pedal position showing the exit of pedal override as pedal position increases toward maximum pedal position. 
           [0021]      FIG. 10  illustrates an exemplary plot of acceleration request as a function of pedal position showing the exit of pedal override as pedal position decreased toward a closed pedal position. 
           [0022]      FIG. 11  illustrates an exemplary plot of acceleration request as a function of pedal position showing decompression of the pedal travel during repetitive entrance and exit of pedal override. 
       
    
    
     DETAILED DESCRIPTION 
       [0023]    Although the figures and the instant disclosure describe one or more embodiments of an accelerator pedal override system for use in connection with vehicle speed limiting systems, one of ordinary skill in the art would appreciate that the teachings of the instant disclosure would not be limited to these embodiments. 
         [0024]    For purposes of this disclosure: 
         [0025]    ⊖ PEDAL —current, unscaled, pedal position. 
         [0026]    ⊖ SCALED   _   PEDAL —accelerator pedal position scaled such that the pedal override trigger point maps to, for example, 50% in the rescaled pedal. 
         [0027]    ⊖ PEDAL@SL —accelerator pedal position at the desired vehicle speed limit. 
         [0028]    ⊖ SCALED   _   PEDAL@PO —the rescaled pedal position that maps the pedal override trigger point to 50% in scaled pedal position. 
         [0029]    ⊖ PedalOverride —pedal position at pedal override. 
         [0030]    ⊖ PedalOverrideNEW —new pedal override trigger point due to pedal decompression. 
         [0031]    a Offset —the desired acceleration offset for the “seat of the pants” feel when pedal override is triggered. 
         [0032]    a PO —the pedal override acceleration request resulting from the pedal override acceleration limit as a function of pedal position. 
         [0033]    a PedalOverride —the pedal override acceleration request resulting from the pedal override acceleration limit as a function of pedal position. 
         [0034]    ⊖ RESCALED   _   PEDAL —the rescaled pedal position used as the input for the pedal override acceleration request function. 
         [0035]    a DriverDemand —the acceleration request from normal driver demand operation. 
         [0036]    a REQUEST —the final acceleration request arbitrated between speed limiting, pedal override and normal driver demand acceleration requests. 
         [0037]    a speedLimiter —the acceleration request resulting from speed limiting operation. 
         [0038]    Tip-out—driver decreasing the pedal position. 
         [0039]    Tip-in—driver increasing the pedal position. 
         [0040]    V LIMIT —desired speed limit, also referred to as VSL. 
         [0041]    VSL—desired speed limit, also referred to as V LIMIT . 
         [0042]    F AD@SL — force due to aerodynamic drag at the speed limit. 
         [0043]    F RR@SL — force due to rolling resistance at the speed limit. 
         [0044]    F wheel@SL —tractive force at the wheel of the vehicle at the speed limit. 
         [0045]    F NET —net force on the vehicle. 
         [0046]    F UNKNOWN —Unknown forces primarily due to added vehicle mass and road grade. 
         [0047]    T ENG@SL —Engine torque at the desired speed limit. 
         [0048]    μ FD —final drive ratio (i.e. differential ratio). 
         [0049]    μ TRANS —transmission gear ratio. 
         [0050]    μ CONV —torque convertor ratio 
         [0051]    r wheel —wheel radius 
         [0052]    T Losses —torque losses in the powertrain 
         [0053]    n ENG@SL —Engine speed at the desired speed limit 
         [0054]    ⊖ SL   _   NOMINAL —pedal position at the desired speed limit under nominal vehicle conditions 
         [0055]    ⊖ RG   _   COMP —pedal compensation for unknown force F UNKNOWN . 
         [0056]    ⊖ PEDAL@PO —pedal position at pedal override. 
         [0057]    ⊖ MRGN —margin above ⊖ PEDAL@SL  used to determine pedal override trigger point. 
         [0058]    a SL   _   RQ   _   FINAL —speed limiter acceleration request at the point pedal override is triggered. 
         [0059]    V ERROR@PO —the vehicle speed error for speed limiting at the point pedal override is triggered 
         [0060]    a PO   _   INIT —the initial acceleration request for the pedal override acceleration request when at the point pedal override is triggered. 
         [0061]    Driver demand—The acceleration or torque request from the driver pressing the accelerator pedal. 
         [0062]    The primary function performed for a vehicle Adjustable Speed Limiter (ASL or ASLD) and Intelligent Speed Limiter (ISL) is to prevent the vehicle speed from exceeding a driver selected desired speed limit (referred to herein as VSL or V LIMIT ). But the driver also expects that if they press the accelerator pedal far enough, they can accelerate the vehicle again and exceed V LIMIT . For some pedal position (and a given set of vehicle conditions), the vehicle speed will be at V LIMIT  and further pedal travel does not result in increased vehicle speed. For purposes herein, that pedal position will be defined as ⊖ PEDAL@SL . 
         [0063]    ⊖ PEDAL@SL  marks the beginning of actively limiting the vehicle speed. This is the basis for the pedal override trigger point. As the pedal position continues to increase beyond ⊖ PEDAL@SL , so does the normal driver demand acceleration request. The driver demand acceleration request is diverging from the speed limiter acceleration request (which is zero at V LIMIT ). 
         [0064]    Pedal travel beyond ⊖ PEDAL@SL  will result in what may be referred to as pedal compression. As the driver continues to press the pedal further, at some point pedal override of V LIMIT  may occur. For a given V LIMIT , pedal override may be some margin above ⊖ PEDAL@SL  which may be intuitive to the driver. 
         [0065]    To trigger pedal override by a driver, a back calculation from the current V LIMIT  to the pedal position is desirable to maintain the current V LIMIT  under current conditions, ⊖ PEDAL@SL  There will be a margin above ⊖ PEDAL@SL  before the transition to pedal override occurs in order to satisfy the primary function, speed limiting. For purposes herein, that margin is defined as ⊖ MRGN . In some embodiments, the value of ⊖ MRGN  may be determined via a statistical sampling of a large enough number of drivers in a survey. 
         [0066]    To determine ⊖ PEDAL@SL , a calculation of the inverse of the driver demand function may be possible: 
         [0000]    
       
      
       F 
       NET 
       =F 
       wheel@SL 
       +F 
       AD@SL 
       +F 
       RR@SL 
       +F 
       UNKNOWN  
      
     
         [0000]        T   ENG@SL =μ FD ×μ TRANS ×μ CONV   ×F   wheel@SL   ×r   wheel   +T   Losses  
 
         [0000]      ⊖ PEDAL@SL   =f   −1 ( T   ENG@SL   ,n   ENG@SL )
 
         [0067]    The calculation from engine torque to pedal position may utilize inverse look-up functions. Alternatively, the ⊖ PEDAL@SL  may be approximated. For example, one approach may include starting with a function that returns a nominal pedal position, ⊖ SL   _   NOMINAL  for standard temperature and pressure conditions on a level road with nominal vehicle weight and nominal rolling resistance based at V LIMIT . 
         [0000]      ⊖ SL   _   NOMINAL   =f   NOMINAL ( V   LIMIT )
 
         [0068]    Assuming that the inverse function is linear and the component F UNKNOWN  maps to a corresponding change in pedal position that enters into the final pedal position calculation additively. An approximation of that function is: 
         [0000]      ⊖ RG   _   COMP   =f ( F   UNKNOWN )
 
         [0069]    Then, the ⊖ SL   _   NOMINAL  could be compensated for F UNKNOWN  as follows: 
         [0000]      ⊖ PEDAL@SL =⊖ SL   _   NOMINAL +⊖ RG   _   COMP  
 
         [0070]    For purposes herein, the pedal position where override occurs may be defined as ⊖ PEDAL@PO  according to the following equation: 
         [0000]      ⊖ PEDAL@PO =⊖ PEDAL@SL +⊖ MRGN  (provides a consistent pedal override position)
 
         [0071]    Now that we know when pedal override may be triggered, the next question is what to do during pedal override. In one embodiment, it may be desirable to return to normal pedal behavior when the driver transitions into pedal override. If the driver demand acceleration request is below the VSL control acceleration request, the VSL is not in control because the normal driver demand is in control. In that situation, pedal override is not needed. 
         [0072]    But it is possible that driver demand acceleration request is above the VSL control acceleration request. In this event, a process to transition back to normal driver demand may be desirable, and optimally via a smooth transition from VSL to driver demand, preferably with no discontinuities in engine torque request that would cause a powertrain clunk or sudden surge in vehicle speed. To the driver, the pedal should feel normal or near normal until normal driver demand can be restored, and preferably without any large or discontinuous increase in torque request during pedal override operation and without a dead pedal feel to the driver during pedal override operation. In addition, the vehicle should preferably register a constant acceleration request for a constant pedal position, and increasing pedal beyond ⊖ PEDAL@PO  should preferably result in an increasing acceleration request. Similarly, decreasing pedal below ⊖ PEDAL@PO  should preferably result in decreasing acceleration request. Upon triggering pedal override, there should preferably be feedback to the driver pedal override has been triggered, a “seat of the pants” feel. At wide open pedal, wide open throttle may be achieved. At closed pedal, minimum torque request may be achieved. Well behaved exit transitions back to driver demand may be preferable. 
         [0073]    We have been controlling the acceleration request to maintain the VSL. During pedal override, the VSL acceleration request may be returned to the driver demand acceleration request. Returning all of the driver demand acceleration when pedal override is entered may result in a surging vehicle as the acceleration transitions from (nominally) 0 to a relatively large amount determined by the current pedal position, which may not be optimal for the driver. 
         [0074]    Another option is to pick up driver demand at the point speed limiting was entered—⊖ PEDAL@SL - and add the pedal travel above ⊖ PEDAL@PO  to it. But this may result in a reduced acceleration request that may not achieve maximum acceleration at 100% pedal, which may not be optimal for the driver. 
         [0075]    Another consideration when trying to use a modified version of normal driver demand is that it is an engine torque request. The performance feel may be inconsistent from one pedal override event to the next as the driver demand acceleration request is dependent on current road conditions. Consequently, the instant disclosure discloses a process that provides a pseudo-normal pedal behavior and transitions from VSL control back to the driver demand to provide a consistent pedal feel for the driver. 
         [0076]    During speed limiting operation an acceleration request may be determined based on vehicle speed error. Once pedal override is entered, vehicle speed error may not be relevant anymore. Instead, what may be relevant is returning to normal driver demand operation. But, it is not preferable to suddenly switch to normal driver demand because of the likelihood of discontinuity in the torque request. Preferably, the transition back to driver demand should feel as close to a normal driver demand as much as possible (i.e. pseudo-normal). For seamless operation, the starting point for a pedal override acceleration request may begin at the last speed limiter acceleration request which may typically, but not necessarily, be 0. 
         [0077]    While in pedal override, system behavior may preferably be: 
         [0078]    1. The vehicle at the speed limit typically has 0 acceleration, and vehicle speed could be less than or greater than the speed limit. Therefore, to account for the speed limiter acceleration request when transitioning to pedal override: 
         [0000]        a   SL   _   RQ   _   FINAL   =f   SL ( V   ERROR@PO ) 
         [0000]    (at pedal override, V ERROR  may not be relevant anymore but the acceleration request at pedal override entry may be relevant.) 
         [0079]    2. The driver may want some acceleration immediately and without the feeling of a dead pedal. When pedal override is achieved, the speed limiter acceleration request may be increased by a meaningful amount to provide a “seat of the pants” feel so entry into pedal override is recognized: 
         [0000]    
       
      
       a 
       PO 
       _ 
       INIT 
       =a 
       SL 
       _ 
       RQ 
       _ 
       FINAL 
       +a 
       Offset  
      
     
         [0000]    (this is where the acceleration request may begin in pedal override.) 
         [0080]    3. The driver may want a normal pedal feel. The transition back to normal driver demand should preferably be transparent. A function that can perform this is as follows: 
         [0000]        a   PO   =f   PO (⊖ PEDAL )+ a   PO   _   INIT  
 
         [0000]    (thus, the acceleration limit may go from initial to maximum when the pedal travels from the ⊖ PEDAL@PO  to 100% pedal, and which allows for deceleration when the pedal goes below ⊖ PEDAL@PO  to 0% pedal.) 
         [0081]    4. f PO  (⊖ PEDAL ) may then continue limiting acceleration request during pedal override and provide the pseudo-normal accelerator pedal feel. But ⊖ PEDAL@PO  may vary based on the desired speed limit and may result in different initial acceleration requests when pedal override is triggered. Thus, for consistency of acceleration response, the pedal may be re-scaled for f PO  (⊖ PEDAL ). In one embodiment, re-scaling such that ⊖ PEDAL@PO  may map to 50% in f PO  (⊖ PEDAL ). For purposes herein, the rescaled pedal will be defined as ⊖ RESCALED   _   PEDAL . 
         [0082]    Turning now to the drawings wherein like reference numerals refer to like elements, there are shown exemplary embodiments and methods for providing pseudo-normal pedal behavior during pedal override and during transition out of pedal override and back to normal driver demand. 
         [0083]      FIGS. 1A-1B  show vehicle  100  in accordance with one embodiment of the instant disclosure. In this embodiment, vehicle  100  is an automobile, though in other embodiments vehicle  100  may be any suitable vehicle (such as a truck, a watercraft, or an aircraft). Vehicle  100  may be a gasoline powered vehicle, a hybrid vehicle, an electric vehicle, a fuel cell vehicle, or any other type of suitable vehicle. Vehicle  100  may include standard features, such as a dashboard, adjustable seats, one or more batteries, an engine or motor, a transmission, an HVAC system including a compressor and electronic expansion valve, a windshield and/or one or more windows, doors, a rear view mirror, a right side view mirror, a left side view mirror, seatbelts, airbags, wheels, and tires. 
         [0084]    As shown in  FIGS. 1A-1B and 2 , vehicle  100  may include sensors  102 , which may be arranged in and around the vehicle in a suitable fashion. Sensors  102  can all be the same or they can vary from one to the next. Sensors  102  may include many sensors or only a single sensor. 
         [0085]    Certain of the sensors  102  may be configured to obtain data about the environment surrounding the vehicle (e.g., position sensors or weather sensors), as indicated by the dashed line in  FIG. 1A , while others obtain data about components of the vehicle itself (e.g., gas level sensors or oil pressure sensors). The sensors  102  may be configured to transmit the data they obtain to one or more controllers of the vehicle  100 , such as to controller  210  (described below), for further processing. The sensors  102  may include any suitable sensor or sensors such as, but not limited to: (1) infrared sensors; (2) visual sensors (such as cameras); (3) ultrasonic sensors; (4) RADAR; (5) LIDAR; (6) laser-scan sensors; (7) inertial sensors (for example, an inertial measurement unit); (8) wheel speed sensors; (9) road condition sensors (to directly measure certain road conditions); (10) rain sensors; (11) suspension height sensors; (12) steering wheel angle sensors; (13) steering torque sensors; (14) brake pressure sensors; (15) tire pressure sensors; or (16) vehicle location or navigation sensors (such as a Global Positioning System). Sensors  102  may include gear sensors configured to detect gear engagement of the vehicle&#39;s transmission, accelerometers configured to detect vehicle acceleration, speed sensors to detect vehicle speed, wheel speed, and/or steering wheel speed, torque sensors to detect engine or motor output torque, driveline torque, and/or wheel torque, and position sensors to detect steering wheel angular position, brake pedal position, and/or mirror position. Some sensors  102  may be mounted inside the passenger compartment of vehicle  100 , around the exterior of the vehicle, or in the engine compartment of vehicle  100 . At least one sensor  102  may be used to identify the vehicle&#39;s driver via facial recognition, speech recognition, or communication with a device, such as a vehicle key or mobile phone personal to the driver. 
         [0086]    Sensors  102  may have an OFF state and various ON states. Vehicle  100 , or a device operatively connected to the vehicle, may be configured to control the states or activity of the sensors. It should be appreciated that the term “internal sensors” includes all sensors mounted to the vehicle, including sensors that are mounted to an exterior of vehicle  100 . 
         [0087]    As shown in  FIG. 2 , in one embodiment, vehicle  100  includes a vehicle data bus  202  operatively coupled to sensors  102 , vehicle drive devices  206 , memory or data storage  208 , a processor or controller  210 , a user interface  212 , communication devices  214 , and a disk drive  216 . 
         [0088]    The processor or controller  210  may be any suitable processing device or set of processing devices such as, but not limited to: a microprocessor, a microcontroller-based platform, a suitable integrated circuit, or one or more application-specific integrated circuits (ASICs). 
         [0089]    The memory  208  may be volatile memory (e.g., RAM, which can include non-volatile RAM, magnetic RAM, ferroelectric RAM, and any other suitable forms); non-volatile memory (e.g., disk memory, FLASH memory, EPROMs, EEPROMs, memristor-based non-volatile solid-state memory, etc.); unalterable memory (e.g., EPROMs); read-only memory; a hard drive; a solid state hard drive; or a physical disk such as a DVD. In an embodiment, the memory includes multiple kinds of memory, particularly volatile memory add non-volatile memory. 
         [0090]    The communication devices  214  may include a wired or wireless network interface to enable communication with an external network. The external network may be a collection of one or more networks, including standards-based networks (e.g., 2G, 3G, 4G, Universal Mobile Telecommunications Autonomous valet parking system (UMTS), GSM® Association, Long Term Evolution (LTE)™, or more); WMAX; Bluetooth; near field communication (NFC); WFi (including 802.11 a/b/g/n/ac or others); WiGig; Global Positioning System (GPS) networks; and others available at the time of the filing of this application or that may be developed in the future. Further, the external network(s) may be a public network, such as the Internet; a private network, such as an intranet; or combinations thereof, and may utilize a variety of networking protocols now available or later developed including, but not limited to, TCP/IP-based networking protocols. The communication devices  214  may also include a wired or wireless interface to enable direct communication with an electronic device, such as a USB or Bluetooth interface. 
         [0091]    The user interface  212  may include any suitable input and output devices. The input devices enable a driver or a passenger of vehicle  100  to input modifications or updates to information shown in, for example, a vehicle display. The input devices may include, for instance, a control knob, an instrument panel, a keyboard, a scanner, a digital camera for image capture and/or visual command recognition, a touch screen, an audio input device (e.g., cabin microphone), buttons, a mouse, or a touchpad. The output devices may include instrument cluster outputs (e.g., dials, lighting devices), actuators, a display (e.g., a liquid crystal display (“LCD”), an organic light emitting diode (“OLED”), a flat panel display, a solid state display, a cathode ray tube (“CRT”), or a heads-up display), and speakers. It should be appreciated that the term pressing a button or feature also includes pressing or activating a virtual button or feature, such as using a mouse to click on an item on a display, or pressing a virtual button on a touch screen. 
         [0092]    The disk drive  216  is configured to receive a computer readable medium. In certain embodiments, the disk drive  216  receives the computer-readable medium on which one or more sets of instructions. The instructions may embody one or more of the methods or logic as described herein. In a particular embodiment, the instructions may reside completely, or at least partially, within any one or more of the main memory  208 , the computer readable medium, and/or within the processor  210  during execution of the instructions. 
         [0093]    The term “computer-readable medium” should be understood to include a single medium or multiple media, such as a centralized or distributed database, and/or associated caches and servers that store one or more sets of instructions. The term “computer-readable medium” also includes any tangible medium that is capable of storing, encoding or carrying a set of instructions for execution by a processor or that cause a system to perform any one or more of the methods or operations disclosed herein. 
         [0094]    In one embodiment, the vehicle  100  includes a one or more computer programs or subprograms  120  stored in the memory  208 . When executed by the processor, the one or more computer programs or subprograms  120  generate or select instructions for other elements of the vehicle to perform. In various embodiments, the one or more computer programs or subprograms  120  are configured to direct instructions to the user interface  212 , the communication devices  214 , the vehicle drive  206 , the sensors  102 , the processor  210 , and any other component operatively connected to the vehicle data bus  202 . It should be appreciated that vehicle  100  may be fully autonomous or partially autonomous. 
         [0095]    In various embodiments, a computing device  105  is operatively connected to the vehicle  100  via any suitable data connection such as WFi, Bluetooth, USB, or a cellular data connection. In one embodiment, shown in  FIG. 3 , the computing device  105  includes a data bus  302 , operatively coupled to sensors  306 , components  316 , memory or data storage  308 , a processor or controller  310 , a user interface  312 , and communication devices  314 . It should be appreciated that the features of the computing device  105  may be similar to the features of the vehicle  100  as described above. For example, the communication devices  314  of the computing device  105  may operate similar to the communication devices  214  of the vehicle  100 . The same applies to the user interface  312 , the sensors  306 , the data storage  308 , the processor  310 , and the disk drive  318 . In various embodiments, the computing device  105  is a mobile phone or a server. 
         [0096]    Turning to  FIGS. 4-5 , there is shown an example method  400  for providing pseudo-normal pedal behavior during pedal override. In this embodiment, pedal position may be considered to be closed at 0% and fully open at 100% pedal travel or angle. Pedal position or angle may be detected by a pedal position sensor, which may transmit the detected signal to a processor in the vehicle, such as by a vehicle speed limit override module or a powertrain control module having a processor and memory, for processing in combination with vehicle speed and acceleration data. As shown in  FIG. 4( a ) , pedal position at which override may occur, ⊖ PEDAL@PO  (item  420 ) lies between the pedal position necessary to maintain the vehicle at the desired speed limit, ⊖ PEDAL@SL  (item  410 ) and 100% pedal travel (item  430 ). The range of pedal position being compressed prior to triggering pedal override is shown as item  440 . After triggering pedal override, the remaining travel of the pedal is shown in  FIG. 4( b ) . Thus, by way of example, of the pedal position to maintain vehicle speed setting of, for example, 60 mph is 45% of the total available pedal travel, and the pedal position necessary to trigger the pedal override function is 70% of the total travel, once pedal override occurs the available travel remaining in the pedal during pedal override is 30%, leaving the driver with the sensation of a compressed range of available pedal travel (item  450 ). To provide the driver with a consistent acceleration response once pedal override is triggered, the remaining available pedal travel may be re-scaled, as shown at item  460  in  FIG. 4( c ) . This allows pedal override to begin at, for example, 50% rescaled pedal position for consistent performance and feel by the driver and ease of calibration of the system. Thus, for pedal positions above which override may occur: 
         [0000]      Above ⊖ PEDAL@PO →⊖ SCALED   _   PEDAL =100−(100−⊖ PEDAL )*[50/(100−⊖ PEDAL@PO )]
 
         [0097]    Using the above example for pedal positions below which override may occur, the opposite may be true. For example, as shown in  FIG. 5( a ) , for pedal positions below the position to maintain the vehicle speed at, for example, 60 mph (item  470 ), this range appears to the driver to have been expanded once pedal override is triggered (item  480 ). To provide the driver with a consistent acceleration response once pedal override is triggered, the remaining available pedal travel may be re-scaled, as shown at item  490  in  FIG. 5( c ) . This allows pedal override to begin at, for example, 50% rescaled pedal position for consistent performance and feel by the driver and easier of calibration of the system. Thus, for pedal positions below which override may occur: 
         [0000]      Below ⊖ PEDAL@PO →⊖ SCALED   _   PEDAL =⊖ PEDAL *(50/⊖ PEDAL@PO )
 
         [0098]    The foregoing discussion provides the same delta rescaled pedal position regardless of whether the vehicle is heavy or light and regardless of whether the vehicle is climbing or descending from a hill. 
         [0099]    From here, as shown in  FIG. 6 , a pedal override acceleration request may be constructed using ⊖ SCALED   _   PEDAL  so as to (1) provide feedback to the driver that pedal override has occurred, namely a Offset , (2) minimize large or discontinuous increases in torque requests during pedal override operation, (3) minimize dead pedal feel during pedal override operation, (4) provide a constant acceleration request for a constant pedal position during pedal override operation, and (5) for increasing pedal position beyond ⊖ PEDAL@PO , an increasing acceleration request is made, and conversely, for decreasing pedal position below ⊖ PEDAL@PO , a decreasing acceleration request is made. 
         [0100]    More specifically,  FIG. 6  shows a representative pedal override acceleration request curve  500  based on a rescaled pedal, with the y-axis representing an acceleration request at the moment of initiation of pedal override and the x-axis representing the rescaled pedal travel from 0% to 100%. At the scaled pedal position at pedal override, ⊖ SCALED   _   PEDAL@PO , feedback is provided to the driver in the form of a small boost in acceleration request, represented as a Offset  (item  502 ), to provide confirmation to the driver that the driver has overcome the speed limit setting. This minimizes the possibility that the vehicle lurches forward due to a relatively large acceleration request that normally would occur with relatively large pedal travel required to overcome the speed limit setting. Thus, the acceleration request after entering pedal override can be represented by: 
         [0000]    
       
      
       a 
       REQUEST 
       =a 
       SL 
       _ 
       RQ 
       _ 
       FINAL 
       +a 
       PO  
      
     
         [0101]    Turning to  FIGS. 7 and 8 , there is shown representative behavior of acceleration requests during speed limiting ( FIG. 7 ) and during pedal override ( FIG. 8 ). For example, during speed limiting, vehicle acceleration may be the minimum of the two accelerations—the acceleration at ⊖ PEDAL@SL  or the ⊖ PEDAL@PO . Upon triggering pedal override, the goal is to suspend or exit speed limiting (item  530 ) and return to normal driver demand (item  540 ), but there may be a large difference in the magnitude of the two accelerations, as shown in  FIG. 7  at items  510  and  520 , respectively. 
         [0102]    To minimize the difference and a possibility of a surge in vehicle acceleration request, a transition to pedal override operation is shown in  FIG. 8 . During pedal override, vehicle acceleration may still be the minimum of the two accelerations. But rescaling the pedal and using an acceleration limit that is a function of the rescaled pedal position allows for a pseudo-normal accelerator pedal behavior. 
         [0103]    Turning to  FIGS. 9 and 10 , there is shown representative solutions for exiting pedal override—when approaching wide open pedal ( FIG. 9 ) and when approaching closed pedal ( FIG. 10 ). More particularly,  FIG. 9  shows a representative entry of pedal override functionality from a speed limiting set point coupled with exit of pedal override functionality when approaching wide open pedal (i.e., near maximum pedal travel), where the acceleration request (y-axis) as function of pedal travel (x-axis). For example,  FIG. 9  point  1  shows the vehicle in speed limiting (curve  530 ) and where the driver increases pedal travel to initiate pedal override of the speed limiting function. At  FIG. 9 , point  2 , pedal override is triggered (i.e., ⊖ PedalOverride ). Further increases in pedal travel results in vehicle acceleration while in pedal override mode due to a pedal override acceleration request, a PedalOverride , as represented at point  3  (curve  500 ). As the driver continues to increase pedal position, at point  4  the pedal override acceleration request curve  500  intersects with the driver demand acceleration request curve  540 , causing pedal override to be exited and the acceleration request continuing thereafter along the normal driver demand acceleration request curve  540  for increasing pedal travel, as shown at point  5 . 
         [0104]      FIG. 10  shows what happens when a decreasing accelerator pedal approaches a closed pedal condition. For example,  FIG. 10  point  1  shows the vehicle in speed limiting (curve  530 ) and where the driver increases pedal travel to initiate pedal override of the speed limiting function. At  FIG. 10 , point  2 , pedal override is triggered (i.e., ⊖ PedalOverride ). Further increases in pedal travel results in vehicle acceleration while in pedal override mode due to a pedal override acceleration request, a PedalOverride , as represented at point  3  (curve  500 ). As the driver decreases pedal position below the pedal override trigger point, ⊖ PedalOverride , the acceleration request decreases below the x-axis (i.e., indicative of deceleration request) along curve  500  to point  4 . As the driver continues to decrease pedal position, at point  5  the pedal override acceleration request curve  500  intersects with the driver demand acceleration request curve  540 , causing pedal override to be exited and the acceleration request continuing thereafter along the normal driver demand acceleration request curve  540  for decreasing pedal travel. 
         [0105]    Another consideration is that with a rescaled pedal, as disclosed herein, there may be a relatively large amount of pedal travel below the pedal override initiation point. A driver may perceive a tip-out to tip-in of the pedal to feel like a dead pedal, where nothing happens in terms of acceleration despite the driver&#39;s movement of the pedal. To solve this problem, the pedal override trigger point may be caused to re-initialize on tip-in of the accelerator pedal, causing positive acceleration to return on tip-in. 
         [0106]      FIG. 11  shows a representative example of how this may work. For example,  FIG. 11  point  1  shows the vehicle in speed limiting (curve  530 ) and where the driver increases pedal travel to initiate pedal override of the speed limiting function. At  FIG. 11 , point  2 , pedal override is triggered (i.e., ⊖ PedalOverride ). Further increases in pedal travel results in vehicle acceleration while in pedal override mode due to a pedal override acceleration request, a PedalOverride , as represented at point  3  (curve  500 ). As the driver decreases pedal position below the pedal override trigger point, ⊖ PedalOverride , the acceleration request decreases below the x-axis (i.e., indicative of deceleration request) along curve  500  to point  4 . When the driver once again increases pedal position, pedal override functionality is reinitialized at the new pedal override position (i.e., ⊖ PedalOverrideNEW ), resulting immediately in a new acceleration request (a pedalOverrideNEW) ) without a dead pedal feel to the driver, as represented along curve  500 ′. 
         [0107]    In another embodiment, the system may be configured to prevent decreasing VSL from triggering pedal override. More specifically, since the pedal override trigger point may be based on the driver set speed limit, it is possible that the driver could have the pedal pressed just less than the pedal override trigger point and then decrease the speed limit. Since the pedal override trigger point may decrease with the new speed limit setting, which may inadvertently trigger a pedal override. To detect and address this possibility, the system may be configured to inhibit entering pedal override unless the driver increases the pedal position a desirable amount, for example approximately 3% over the speed limit setting, before the pedal is decreased to less than the new pedal override trigger point. 
         [0108]    While specific embodiments have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the disclosure herein is meant to be illustrative only and not limiting as to its scope and should be given the full breadth of the appended claims and any equivalents thereof.