Patent Publication Number: US-2023139530-A1

Title: Vehicle controller, vehicle including a vehicle controller, and method of operating a vehicle

Description:
FIELD OF THE INVENTION 
     The present invention relates to a vehicle controller, a vehicle including a vehicle controller, and a method of operating a vehicle. 
     BACKGROUND INFORMATION 
     Many vehicles, for example, automobiles, with a multi-gear transmission include a reverse gear for propelling the vehicle in a reverse direction. In vehicles driven by an internal combustion engine, engine torque typically increases from idle speed, reaches a maximum, and then decreases as engine speed reaches its upper limit. Consequently, a vehicle driven by an internal combustion engine may exhibit a relatively low driving torque at low engine speeds and drastically higher driving torque with increasing engine speed followed by a precipitous reduction in driving torque at even higher engine speeds. This characteristic can lead to dangerous operating conditions in instances where, for example, an obstacle interferes with the driver&#39;s ability to propel the vehicle in the reverse direction. If, when faced with such an obstacle at a very low vehicle speed, the driver further depresses the accelerator to overcome the obstacle, the torque response of the engine may result in a disproportionate increase in driving torque, causing the vehicle to hurtle unexpectedly in the reverse direction. A similar effect can occur when driving in the lowest forward gear. Given the configuration and constraints of an internal combustion engine and its transmission, it is not possible to modify the vehicle&#39;s torque-engine speed relationship during operation of the vehicle. 
     While certain motorcycles or other two-wheeled vehicles may include a reverse gear, many do not. Thus, in motorcycles that lack a reverse gear, the driver must manually walk or push the motorcycle in the rearward direction. In motorcycles that include a reverse gear, it is awkward and difficult to maneuver the motorcycle in the rearward direction, since the driver may have to simultaneously operate the clutch lever, located on the left-hand side of the handlebar, the throttle, located on the right-hand side of the handlebar, the front brake lever, also located on the right-hand side of the handlebar, the rear brake pedal, located on the right-hand side of the motorcycle, and the gear-change lever, located on the left-hand side of the motorcycle, all while steering with the handlebar and turning their upper body to look rearward. 
     Certain motorcycles lack a reverse gear but can be propelled in the rearward direction by operating the starter motor in a special reverse mode. However, since starter motors are not typically designed for propelling a vehicle, employing a starter motor as a reversing mechanism may result in excessive or premature wear and failure of the starter motor. Additionally, starter motors are generally designed to operate in short bursts, providing high torque at the engine&#39;s minimum cranking speed. This high torque requires significant battery power consumption. Thus, utilizing a vehicle&#39;s starter motor for propulsion may overly tax the vehicle&#39;s battery and other electrical systems and may overheat the motor, resulting in premature failure. 
     There is believed to be a need to provide for operation of a two-wheeled electric vehicle in a low-speed mode, in which the maximum driven speed of the vehicle is significantly below the normal driving speed and the maximum driven speed of the vehicle, e.g., to assist the driver of the vehicle in parking, maneuvering in tight spaces, in overcoming obstacles, etc. 
     SUMMARY 
     According to an example embodiment of the present invention, a system for a wheeled vehicle includes: an electric motor adapted to drive at least one wheel of the vehicle to propel the vehicle, the electric motor having a predetermined maximum torque output; an energy storage device adapted to supply electrical energy to the electric motor; and a controller adapted to control the supply of electrical energy to the electric motor to control an amount of torque output by the electric motor. The controller is adapted to selectively operate the vehicle in a low-speed mode to limit a driven speed of the vehicle to a maximum driven speed that is below a maximum speed of the vehicle, and the controller adapted to control the amount of torque output by the electric motor in the low-speed mode according to an inverse relationship between the amount of torque output by the electric motor and the driven speed of the vehicle. Additionally, the controller is adapted to control the amount of torque output by the electric motor in the low-speed mode toward the predetermined maximum torque output of the electric motor at a zero vehicle speed and to reduce the amount of torque output by the electric motor in the low-speed mode with increasing vehicle speed. 
     The controller may be adapted to selectively propel the vehicle in a forward direction and in a rearward direction in the low-speed mode. 
     The controller may be adapted to switch between propulsion of the vehicle in the forward direction and in the rearward direction. 
     The system may include at least one user-operable control component, and the controller may be adapted to switch between propulsion of the vehicle in the forward direction and in the rearward direction in response to operation of the user-operable control component. 
     The system may include a display device adapted to display a visual indication that the controller is operating the vehicle in the low-speed mode. 
     The controller may be adapted to selectively operate the vehicle in the low-speed mode in response to a predetermined sequence of operation of components of the vehicle. 
     The controller may be adapted to prevent activation of the low-speed mode unless a predetermined set of conditions is satisfied. 
     The predetermined set of conditions may include a kickstand of the vehicle being in a lowered position and a speed of the vehicle being zero. 
     The maximum driven speed of the vehicle in the low-speed mode may be approximately 3 mph. 
     The user-operable control component may include a front brake lever of the vehicle. 
     The user-operable control component may include a front brake lever located on a right side of a handlebar of the vehicle and a further control component located on the right side of the handlebar of the vehicle, and the controller adapted to switch between propulsion of the vehicle in the forward direction and in the rearward direction in response to simultaneous operation of the front brake lever and the further control component. 
     The further control component may include a button and/or a switch. 
     The controller may be adapted to switch between propulsion of the vehicle in the forward direction and in the rearward direction in response to simultaneous operation of the front brake lever and the further control component for a predetermined length of time. 
     The controller may be adapted to selectively propel the vehicle in a forward direction and in a rearward direction in the low-speed mode by controlling a rotational direction of the electric motor. 
     The electric motor may be arranged as three-phase AC motor. 
     The controller may be adapted to control the amount of torque output by the electric motor in the low-speed mode by controlling a current, voltage, and/or frequency of the electrical energy supplied to the electric motor from the energy storage device. 
     The energy storage device may include a battery. 
     The battery may be arranged as a lithium ion battery. 
     The vehicle may be arranged as an electric motorcycle. 
     According to an example embodiment of the present invention, a two-wheeled vehicle includes: a front wheel; a rear wheel; an electric motor adapted to drive at least one of the wheels to propel the vehicle, the electric motor having a predetermined maximum torque output; a battery adapted to supply electrical energy to the electric motor; and a controller adapted to control the supply of electrical energy to the electric motor to control an amount of torque output by the electric motor. The controller is adapted to selectively operate the vehicle in a low-speed mode to limit a driven speed of the vehicle to a maximum driven speed that is below a maximum speed of the vehicle, and the controller adapted to control the amount of torque output by the electric motor in the low-speed mode according to an inverse relationship between the amount of torque output by the electric motor and the driven speed of the vehicle. Additionally, the controller is adapted to control the amount of torque output by the electric motor in the low-speed mode toward the predetermined maximum torque output of the electric motor at a zero vehicle speed and to reduce the amount of torque output by the electric motor in the low-speed mode with increasing vehicle speed. 
     Further features and aspects of example embodiments of the present invention are described in more detail below with reference to the appended schematic Figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic right side view of a two-wheeled vehicle according to an example embodiment of the present invention. 
         FIG.  2    is a schematic left side view of the vehicle. 
         FIG.  3    schematically illustrates the controls of the vehicle. 
         FIG.  4    is a schematic view of the left-hand controls of the vehicle. 
         FIG.  5    is a schematic view of the right-hand controls of the vehicle. 
         FIG.  6    is a schematic block diagram of the vehicle. 
         FIGS.  7   a  to  7   d    schematically illustrate a dash display of the vehicle in corresponding operating modes of the vehicle. 
         FIG.  8    is a flowchart that schematically illustrates a method of operating a vehicle according to an example embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG.  1    is a schematic side view of a two-wheeled vehicle  100 , e.g., a motorcycle, according to an example embodiment of the present invention, and  FIG.  2    is a schematic left side view of the vehicle  100  illustrated in  FIG.  1   . As illustrated in  FIGS.  1  and  2   , the vehicle  100  is arranged as an electric motorcycle and includes a controller  130 , a front wheel  102 , a rear wheel  104 , and electric motor  108 , e.g., an air-cooled, brushless, permanent-magnet 3-phase AC motor, powered by an energy storage device  132 , e.g., a battery, a lithium ion battery, an integrated battery, a hot-swappable battery, etc., to drive the rear wheel  104  to thereby propel the vehicle  100  according to the driver&#39;s operation thereof. Since the vehicle  100  is arranged as an electric vehicle, e.g., an electric motorcycle, it lacks an internal combustion engine and associated transmission, and its only source of propulsion is electric motor  108 . The electric motor  108  may be driven in either rotational direction to thereby selectively propel the vehicle  100  in the forward direction or the reverse direction, depending on the rotational direction of the electric motor  108 . In other words, the driving direction of the vehicle  100  does not rely on the engagement of particular gears or on the use of a transmission. The motor  108  may be arranged as a direct drive motor, adapted to drive the rear wheel  104  via a belt, chain, or driveshaft. 
     While the vehicle  100  is described above as being an electric vehicle (EV), the vehicle  100  may be arranged as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), etc. 
     The vehicle  100  includes a seat  110  to accommodate the driver, and, optionally, a passenger, and a handlebar  112  that includes controls for the driver to operate the vehicle  100 , as described in more detail below. The front wheel  102 , the rear wheel  104 , the motor  108 , and the battery  132 , for example, are mounted to frame  106 . 
     The vehicle  100  further includes a kickstand  136  that can be retracted, e.g., raised, for normal driving, or extended, e.g., lowered, to support the vehicle  100  when parked. A kickstand sensor  138  detects whether the kickstand  136  is in the retracted or extended position and is arranged as a safety feature to prevent operation, e.g., propulsion, of the vehicle  100  if the kickstand  136  is in the extended, e.g., lowered, position. 
     Moreover, the vehicle  100  includes a brake light  140 , which is normally illuminated when the front brake lever  120  and/or the rear brake pedal  148  is operated to engage the vehicle&#39;s brakes, rear turn signals  142  and front turn signals  146 , which are normally illuminated, e.g., blink, when the driver operates the vehicle&#39;s turn signal switch to indicate their intention to make a left-hand or right-hand turn or lane change, and a headlight  144 , which is normally illuminated during regular driving operation of the vehicle  100 , e.g., as a daytime running light. 
       FIG.  3    schematically illustrates the controls of the vehicle  100  illustrated in  FIGS.  1  and  2   . Mounted on the handlebar  112  are right handgrip  114 , which includes the vehicle&#39;s throttle/accelerator, left handgrip  116 , front brake lever  120 , key switch  122 , which may also include a steering lock feature, right switchgear  124 , and left switchgear  126 . Additionally, a dash display  118  is provided and may be arranged as a display, e.g., an LCD panel, a touch screen, etc. 
       FIG.  4    is a schematic view of the left-hand controls of the vehicle  100 , and  FIG.  5    is a schematic view of the right-hand controls of the vehicle  100 . As mentioned above, the left-hand controls include left handgrip  116  and left switchgear  126 , and the right-hand control include right handgrip  114 , front brake lever  120 , and right switchgear  124 . The left switchgear  126  may include a number of operating components for operating or controlling associated vehicle systems or features, including, for example, switches to operate the vehicle&#39;s headlight  144 , to switch between high and low beams of the headlight  144 , to operate the headlight  144  on a flash-to-pass basis, a switch to operate the turn signals  142 ,  146  as hazard warning flashers, a turn signal switch to operate the turn signals  142  and  146  as flashing indicators to reflect the driver&#39;s intention to make a turn, e.g., at an intersection, or to change lanes, a button to operate the vehicle&#39;s horn, a mode switch  152  to change operating modes of the vehicle  100 , etc. The right switchgear  124  may also include a number of operating components for operating or controlling associated vehicle systems or features, including, for example, a motor start stop switch  134 , a cruise control switch  150  for operating the vehicle&#39;s cruise control feature, etc. 
     The motor start stop switch  134  may be arranged as a rocker or toggle switch having two operating positions: a start position and a stop position. In the stop position, also referred to as the OFF or kill position, the motor start stop switch  134  switches off power to the motor  108 , to prevent the motor  108  from propelling the vehicle  100 , and in the start position, also referred to as the ON or run position, switches on power to the motor  108 , to allow the motor  108  to propel the vehicle  100 . It should be appreciated that the start stop switch  134  does not turn off (or on) power to other circuits of the vehicle  100 . Rather, the key switch  122  may operate as a main power switch, powering off most, or all, circuits of the vehicle  100  in the OFF position and powering on most, or all, circuits of the vehicle  100  in the ON position. 
       FIG.  6    is a schematic block diagram of vehicle  100 . As illustrated in  FIG.  6   , the controller  130  may include one or more electronic control units (ECUs), microprocessors, memory units (e.g., non-volatile memory units, volatile memory units, firmware, and/or non-transitory storage devices) adapted to store data and control instructions and/or software for operation of the vehicle  100 , other hardware or logic circuitry, etc. The controller  130  may be arranged as a single, integrated unit, e.g., integrated with the dash display  118 , or it may be arranged as a plurality of sub-units distributed throughout the vehicle  100 .  FIG.  6    schematically illustrates the controller  130  as including a processor, a microprocessor, other logic unit(s), circuitry, hardware, and/or firmware, collectively indicated by reference numeral  154 , memory unit(s)  156 , and software  158 , e.g., stored in a non-transitory computer readable storage medium as a set of instructions that are executable by a processor. For example, the controller  130  may include microprocessor adapted to execute the set of instructions stored in the non-transitory computer readable storage medium to perform the processes described herein. 
     As illustrated in  FIG.  6   , controller  130  is connected to and in communication with, for example, motor  108 , throttle  114 , dash display  118 , front brake lever  120 , key switch  122 , battery  132 , start stop switch  134 , kickstand sensor  138 , brake light  140 , headlight  144 , taillights  142 ,  146 , rear brake pedal  148 , cruise control switch  150 , and mode switch  152 . While  FIG.  6    illustrates a direction connection between controller  130  and the foregoing components of the vehicle  100 , it should be appreciated that the controller  130  and the foregoing components of the vehicle  100  may be indirectly connected and may indirectly communication with each other via, for example, one or more buses of the vehicle  100 , e.g., a CAN bus. Moreover, while  FIG.  6    illustrates controller  130  being connected to and in communication with all of the foregoing components of the vehicle  100 , it should be appreciated that a subset of those components may be connected to and in communication with the controller  130 . 
     The controller  130  may be adapted to enter a low-speed mode, referred to, for example, as a creep mode or park mode, in which the speed that the vehicle  100  is propelled is limited to that which is similar to a walking speed, e.g., approximately 3 mph, e.g., between 2.5 and 3.5 mph, between 2 and 4 mph, between 1 and 5 mph, etc. Thus, for example, the speed limit in the low-speed mode is significantly below the normal operating speeds of the vehicle  100 , e.g., 20 to 60 mph, and its top speed, e.g., 80 to 130 mph. 
     The controller  130  may be adapted to require a particular and specific sequence of operations of one or more of the operational components of the vehicle  100  in order to enter or engage the low-speed mode. This requirement may avoid or at least reduce or minimize the possibility of entering or engaging the low-speed mode accidentally or unintentionally. 
     This is particularly important when the vehicle  100  is at a standstill, since entering or engaging the low-speed mode accidentally or unintentionally could cause damage to the driver, pedestrians, the vehicle  100 , other property, etc. 
     For example, entering or engaging the low-speed mode may require the operator of the vehicle  100  to navigate through one or more on-screen menus presented on the dash display  118 . Once the low-speed mode is engaged, the dash display  118  switches from its normal operating mode, schematically illustrated in  FIG.  7     a,  in which, for example, vehicle speed, odometer, trip odometer, vehicle range, etc., may be displayed to the driver, to low-speed mode displays, schematically illustrated in  FIGS.  7   b    and  7   c.  In the low-speed driving mode, the dash display  118  may present limited information to the driver, to highlight that the vehicle  100  is in the low-speed mode and to minimize distractions to the driver. While in the low-speed mode, the vehicle  100  may be selectively driven in the reverse or forward direction, and the driver of the vehicle  100  may toggle between the reverse and forward directions, as described in more detail below. When first entering the low-speed mode, the controller  130  may be adapted to cause the motor  108  to propel the vehicle  100  in the reverse direction, based on the assumption that the driver would most likely utilize the low-speed mode for backing up the vehicle  100 . However, the controller  130  may be adapted to cause the motor  108  to propel the vehicle  100  in the forward direction upon first entering the low-speed mode. The driving direction, as noted above, depends on the rotational direction of the motor  108 . 
     For example, as illustrated in  FIG.  7     b,  while in the low-speed mode, the dash display  118  may prominently display an arrow  160  pointing rearward along with the text “REVERSE”  162 , to indicate to the driver of the vehicle  100  that the vehicle will be propelled in the rearward driving direction, and as illustrated in  FIG.  7     c,  while in the low-speed mode, the dash display  118  may prominently display an arrow  168  pointing forward along with the text “FORWARD”  170 , to indicate to the driver of the vehicle  100  that the vehicle will be propelled in the forward driving direction. Thus, the driver of the vehicle  100  may quickly and readily ascertain the driving direction of the vehicle  100  by looking at the dash display  118 . Additionally, as illustrated in  FIGS.  7   b    and  7   c,  while the vehicle is in the low-speed mode, the dash display  118  may include a symbolic indication  164  to indicate to the driver of the vehicle  118  that the vehicle  100  is in the low-speed mode. As an example, the symbolic indication  164  may be the letter “P” enclosed in a circle. Additionally, as illustrated in  FIGS.  7   b    and  7   c,  the driving speed  166  of the vehicle  100  may be indicated. If the dash display  118  is implemented as a touch screen, the driver of the vehicle  100  may toggle between the reverse and forward driving directions by pressing or tapping on a designated area of the dish display  118 , e.g., in the vicinity of the arrow  160  or  168  and/or text  162  or  170 . The driver of the vehicle  100  may operate one of the other operating controls, e.g., the cruise control switch  150 , to toggle between the reverse and forward driving directions. For example, while the low-speed mode is engaged to propel the vehicle  100  in the reverse direction, a short press, e.g., a press for less than one second, of the operating control, e.g., the cruise control switch  150 , toggles the low-speed mode to the forward driving direction, and while the low-speed mode is engaged to propel the vehicle  100  in the forward direction, a short press, e.g., a press for less than one second, of the operating control, e.g., the cruise control switch  150 , toggles the low-speed mode to the reverse driving direction. Thus, the driver of the vehicle  100  may quickly and readily toggle between the driving directions. In addition to the dash display screens illustrated in  FIGS.  7   b    and  7   c,  the dash display  118  may display the screen illustrated in  FIG.  7   d    upon initial entry into the low-speed mode but before the vehicle  100  is in condition to be driven, as described in more detail below. 
     In addition, or as an alternative, to entering or engaging the low-speed mode by navigating through a menu structure on the dash display  118 , the low-speed mode may be entered or engaged by operating certain vehicle controls in a particular sequence. For example, the driver of the vehicle  100  may enter or engage the low-speed mode in the condition that the vehicle  100  is stopped, and upon initial activation of the low-speed mode, the vehicle  100  may be driven in the reverse direction up to the maximum low-speed limit of, for example, approximately 3 mph, e.g., between 2.5 and 3.5 mph, between 2 and 4 mph, between 1 and 5 mph, etc. As a further example, the driver of the vehicle  100  may enter or engage the low-speed mode by operating a dedicated or multi-function switch, button, other control device, e.g., located on or at the handlebar  112 , in, on, or at the switchgear  124 ,  126 , on or at the dash of the vehicle  100 , etc. The driver may selectively switch or toggle between the reverse and forward driving directions, and the driver may selectively exit the low-speed mode at any time. 
       FIG.  8    is a flowchart that schematically illustrates a method of operating a vehicle, e.g., vehicle  100 , according to an example embodiment of the present invention. It should be understood that the method may be performed by controller  130 , e.g., by processor  154  performing a set of instructions, e.g., software  156 , stored in a non-transitory computer readable storage medium, such as memory  158 . 
     The method starts at S 100 , while, for example, the vehicle  100  is operating in its normal operating mode, e.g., in a mode other than the low-speed mode. 
     In order to enter or engage the low-speed mode, the controller  130  makes an initial set of determinations to ascertain whether the vehicle  100  may safely enter the low-speed mode. 
     For example, at S 102 , the controller  130  determines whether the vehicle  100  is stationary, e.g., its speed is zero, or at or below a threshold, e.g., the vehicle speed is less than, less than or equal to, or not greater than the maximum vehicle speed of the low-speed mode. The controller  130  may make this determination based on the rotational speed of the motor  108 , the position of the throttle  114 , the front brake lever  120 , and/or the rear brake pedal  148 , a vehicle speed sensor, wheel speed sensor(s) at the front wheel  102  and/or the rear wheel  104 , etc. In the condition that the vehicle  100  is not stationary or its speed exceeds the threshold, the method stops at S 132 , otherwise, the method proceeds to S 104 . 
     At S 104 , the controller  130  determines whether the kickstand  136  is in the lowered or extended position and/or whether the kickstand  136  is in the raised or retracted position. For example, the controller  130  makes this determination based on the kickstand sensor  138 . In the condition that the kickstand  136  is in the raised or retracted position, or is not in the lowered or extended position, the method stops at S 132 , otherwise, the method proceeds to S 106 . 
     At S 106 , the controller  130  determines whether the start stop switch  134  is in the STOP position, also referred to as the OFF or KILL position, or is not in the START, also known as the ON or RUN position. In the condition that the stop start switch  134  is in the START position, or is not in the STOP position, the method stops at S 132 , otherwise, the method proceeds to S 108 . 
     At S 108 , the controller  130  is prepared to enter or engage the low-speed mode. It should be appreciated that the determinations in S 102 , S 104 , S 106  may be made in the order illustrated in  FIG.  8    or may be made in a different order. Moreover, these determinations may be made simultaneously or sequentially. Additionally, it is possible for the controller  130  to ascertain that the vehicle  100  is in a stopped state, in which it is safe to enter or engage the low-speed mode, by making only one of the determinations in S 102 , S 104 , S 106 , only two of the determinations in S 102 , S 104 , S 106 , or all three determinations in S 102 , S 104 , S 106 . The controller  130  may also determine that the vehicle  100  is in a stopped state by evaluating data from a GPS or other navigation system included in the vehicle  100 . The controller  130  may also make a determination as to whether a driver or operator of vehicle  100  is present on or at the seat  110  based on a weight or proximity sensor and only permit entry or engagement of the low-speed mode in the condition that the weight or proximity sensor detects the presence of a driver or operator of the vehicle  100 . 
     Once the conditions that permit entry or engagement into the low-speed mode have been met, the low-speed mode may be entered or engaged by navigating the menu structure of the vehicle  100  via the dash display  118  as described above. The method proceeds from S 108  to S 110 . 
     At S 110 , the dash display  118  is set to display the low-speed display, such as that illustrated in  FIGS.  7   b    and  7   c.  Thus, for example, prior to S 108 , the dash display  118  may display the screen illustrated in  FIG.  7     a,  and between S 110  and S 132 , the dash display  118  may switch to the low-speed display, such as that illustrated in  FIGS.  7   b    and  7   c,  depending on the driving direction of the vehicle  100 . After S 110 , the method proceeds to S 112 . 
     Although the low-speed mode is entered or engaged at S 110 , the vehicle  100  is prevented from being propelled by the motor  108  until certain conditions are met, as determined, for example, by the controller  130 . Thus, rather than initially displaying the screens illustrated in  FIGS.  7   b    and  7   c,  the dash display  118  may initially display the screen illustrated in  7   d  upon entering the low-speed mode. As illustrated in  FIG.  7     d,  the dash display  118  provides a textual indication  172  that the low-speed mode has been entered or activated, e.g., by displaying “PARKING MODE” thereon. Additionally, the dash display  118  may provide visual indications  174 ,  178  of status actions that the driver of the vehicle  100  must take in order to propel the vehicle  100  in the low-speed mode, e.g., by indicating that the kickstand  136  must be raised or retracted, for example, by displaying an icon  174 , that the start stop switch  134  must be set to the START position, for example, by displaying another icon  178 . After each of these actions are taken, the dash display may turn off the respective icon  174  or  178 , such that only remaining actions necessary to propel the vehicle  100  in the low-speed mode are indicated. Once all actions necessary to allow the vehicle  100  to be propelled in the low-speed mode have been take, the dash display  118  may then stop displaying the screen illustrated in  FIG.  7   d    and thereafter display the screens illustrated in  FIGS.  7   b    and  7   c,  depending on the driving direction of the vehicle  100 . 
     At S 112 , the controller  130  determines whether the kickstand  136  has been raised or retracted, or is no longer in the lowered or extended position. This determination may be made by the controller  130  based on the kickstand sensor  138 . In the condition that the kickstand is in the lowered or extended position, or is not in the raised or retracted position, the vehicle  100  is not propelled, and the vehicle  100  remains in the low-speed mode, otherwise, the method proceeds to S 114 . 
     At S 114 , the controller  130  determines whether the start stop switch  134  is in the START position. In the condition that the start stop switch  134  is in the STOP position, or is not in the START position, the vehicle  110  is not propelled, and the vehicle remains in the low-speed mode, otherwise the method proceeds to S 116 . It should be appreciated that the determinations S 112  and S 114  may be made in the order illustrated in  FIG.  8    or may be made in the reverse order. Moreover, it is possible that the controller  130  only makes one of these determinations S 112  and S 114 , e.g., only S 114 . 
     At S 116 , the low-speed mode is entered or engaged, and the motor  108  is operated by the driver of the vehicle  100  to propel the vehicle  100  in the reverse direction in accordance with the rotational driving direction of the motor  108 . It is alternatively possible that the motor  108  is operated to propel the vehicle  100  in the forward direction upon first entering the low-speed mode. The method proceeds from S 116  to S 118 . The driving direction of the vehicle  100  upon first entering the low-speed mode may be fixed or may be user-definable, e.g., the driving direction upon first entering the low-speed mode may be fixed as the reverse direction, fixed as the forward direction, or selected by the operator. For example, for so-called street bikes, e.g., cruisers, roadsters, touring motorcycles, the driving direction of the vehicle  100  upon first entering the low-speed mode may be set to the reverse direction, e.g., to facilitate parking, to assist the driver in maneuvering in tight spaces or on an incline, etc., whereas, for example, for so-called sport bikes, dirt bikes, etc., the driving direction of the vehicle  100  upon first entering the low-speed mode may be set to the forward direction, e.g., to assist the driver in maneuvering or overcoming obstacles. 
     At S 118 , the dash display  118  displays the screen illustrated, for example, in  FIG.  7     b.  If, however, the motor  108  is operated to propel the vehicle in the forward direction upon first entering the low-speed mode, the dash display  118  displays the screen illustrated, for example, in  FIG.  7     c.  While in the low-speed mode, as mentioned above, the speed of the vehicle  100  is limited, for example, by the controller  130  to, e.g., approximately 3 mph, e.g., between 2.5 and 3.5 mph, between 2 and 4 mph, between 1 and 5 mph, etc. Thus, for example, regardless of throttle position, the controller  130  may limit the rotational speed of the motor  108  so that the speed of the vehicle  100 , while in the low-speed mode, does not exceed this low-speed limit. It should be appreciated that the low-speed limit may be fixed, may be variable, and/or may be user-definable. 
     In certain situations, the operator of the vehicle  100  may set a lower or higher low-speed limit than those mentioned above and/or than a factory-default or factory-set low-speed limit. For example, a lower or higher low-speed limit may be, e.g., permanently, temporarily, etc., set for an indoor demonstration, display, or show, e.g., at a dealership, trade show, exhibit space, test drive, etc., to permit demonstration of operation of the vehicle  100 , e.g., in the low-speed mode and/or in the normal operating mode of the vehicle  100 , without operating the vehicle  100  in its full power/speed operation. That is, for example, the low-speed mode may not only be utilized for assisting the driver of the vehicle  100  in parking, maneuvering in tight spaces, in overcoming obstacles, etc., but also in training or teaching a driver, e.g., a first-time motorcycle rider, how to drive the vehicle  100 , in indoor driving of the vehicle  100 , during test drives of the vehicle  100 , etc. Additionally, the low-speed limit may be the same in the reverse driving and forward driving directions but may be different. 
     For example, the low-speed limit in the reverse driving direction may be lower or higher than in the forward driving direction. 
     The driver of the vehicle  100  may, at their discretion, exit the low-speed mode at any time after entering or engaging the low-speed mode. For example, at S 120 , it is determined whether to exit the low-speed mode, and, if so, the method stops at S 132 . Among the actions that indicate the driver&#39;s intent to exit the low-speed mode are: lowering the kickstand  136 , e.g., based on a signal from the kickstand sensor  138 ; setting the start stop switch  134  to STOP; turning the key switch  122  to the OFF position; exiting the low-speed mode by navigating through one or more on-screen menus presented on the dash display  118 ; operating one or more designated control components of the vehicle  100 ; etc. Thus, the controller  130  may, upon detection of one or more of these events, exit the low-speed mode and stop the method at S 132 . If the low-speed mode should be maintained, e.g., the low-speed mode should not be exited, the method proceeds to S 122 . 
     At S 122 , it is determined whether the driving direction should be changed, e.g., toggled or switched from the reverse driving direction to the forward driving direction. The operator of the vehicle  100  may change driving directions, for example, by pressing a designated location on the dash display  118 , e.g., a touch screen, as mentioned above. Alternatively, the operator may be required to operate one or more of the controls of the vehicle  100 . For example, the driving direction while in the low-speed mode may be switched or toggled between the forward and reverse driving directions while simultaneously operating the front brake lever  120 , which is provided on the right side of handlebar  112 , and another control component provided on the right switchgear  124 , e.g., a press of the cruise control switch or button  150  for less than one second, for example. Thus, the driver may quickly and readily toggle between forward and reverse driving directions using the controls on one side of the handlebar  112 . Requiring two simultaneous actuations of control components on one side of the handlebar  112  reduces, minimizes, and/or eliminates the risk that the driver of the vehicle  100  would accidentally or unintentionally switch driving directions. Therefore, safety for the driver, pedestrian, the vehicle  100 , and other property is improved. In the circumstance that the driving direction is not to be changed, the low-speed mode, in the reverse driving direction, is maintained, otherwise, the method proceeds to S 124 . 
     At S 124 , the low-speed mode is maintained, and the driving direction is switched to the forward driving direction. Additionally, any change in maximum speed is also made, if the maximum speed in the forward direction is different than the maximum speed in the reverse direction. Thus, when propelled by motor  108 , the vehicle  100  travels in the forward direction, limited by the controller  130  to the maximum speed of, for example, approximately 3 mph, e.g., between 2.5 and 3.5 mph, between 2 and 4 mph, between 1 and 5 mph, etc. As mentioned above, the maximum speed in the low-speed mode may be the same for the forward and reverse driving directions or may be different for the forward and reverse driving speeds. For example, the low-speed limit in the forward driving direction may be higher or lower than in the reverse driving direction. Thus, for example, regardless of throttle position, the controller  130  may limit the rotational speed of the motor  108  so that the speed of the vehicle  100 , while in the low-speed mode, does not exceed this low-speed limit. As noted above, the driving direction is determined by the rotational direction of the motor  108 , and reversing the rotational direction of the motor  108  results in reversing the travel direction of the vehicle  100 . The method then proceeds to S 126 . 
     At S 126 , the screen displayed on the dash display  118  is switched to the screen illustrated, for example, in  FIG.  7     c.  The method then proceeds to S 128 . 
     As mentioned above, the driver of the vehicle  100  may, at their discretion, exit the low-speed mode at any time after entering or engaging the low-speed mode. For example, at S 128 , it is determined whether to exit the low-speed mode, and, if so, the method stops at S 132 . Among the actions that indicate the driver&#39;s intent to exit the low-speed mode are: lowering the kickstand  136 , e.g., based on a signal from the kickstand sensor  138 ; setting the start stop switch  134  to STOP; turning the key switch  122  to the OFF position; exiting the low-speed mode by navigating through one or more on-screen menus presented on the dash display  118 ; operating one or more designated control components of the vehicle  100 ; etc. Thus, the controller  130  may, upon detection of one or more of these events, exit the low-speed mode and stop the method at S 132 . If the low-speed mode should be maintained, e.g., the low-speed mode should not be exited, the method proceeds to S 130 . 
     At S 130 , it is determined whether the driving direction should be changed, e.g., toggled or switched from the forward driving direction to the reverse driving direction. In the circumstance that the driving direction is not to be changed, the low-speed mode, in the forward driving direction, is maintained, otherwise, the method proceeds to S 116 . 
     It should be understood that the actions of the method illustrated in  FIG.  8    may be performed in the order illustrated in  FIG.  8    or may be performed in different orders. Moreover, the method may include lesser or additional actions. Additionally, the controller  130  may perform some, or all, of the actions, or multiple components of the vehicle  100  may perform the method. 
     As described above, the dash display  118  may display particular screens while the vehicle  100  is in the low-speed mode, in order to provide an indication to the driver that the low-speed mode is active and the direction of travel of the vehicle  100 . To alert pedestrians, drivers of other vehicles, etc., that the vehicle  100  is a low-speed mode, especially since the vehicle  100  is a battery-powered motorcycle that emits substantially low or no sounds, particularly at a standstill or low speed, the controller  130  may cause the brake light  140 , the rear turn signal lights  142 , the headlight  144 , the front turn signal lights  146 , the horn, etc., to indicate, e.g., visually, for example, by flashing or blinking, or audibly, that the vehicle  100  is in an active driving mode. 
     As noted above, in the low-speed mode, the maximum speed is, for example, approximately 3 mph, e.g., between 2.5 and 3.5 mph, between 2 and 4 mph, between 1 and 5 mph, etc., and may be approximately an average person&#39;s walking speed. Therefore, in the low-speed mode, the operator of the vehicle  100  should be able to maintain control of the vehicle  100  as though walking the vehicle  100  forward or backward, e.g., to park, maneuver in tight spaces, overcome obstacles on the road or a trail, etc. Since the vehicle  100  is driven by an electric motor  108  powered by a battery  132 , or other storage device, it is possible to control, e.g., by controller  130 , the torque, power, and speed of the vehicle  100  by controlling the motor  108  and/or power delivered by battery  132  to the motor  108 . For example, the controller  130  may control the battery  132  and/or motor  108  so that the motor&#39;s maximum torque is available to propel the vehicle  100  forward or backward from a standstill. Therefore, from a standstill, the vehicle  100  may readily overcome an obstacle, static friction among vehicle components and the driving surface, etc. However, to reduce, minimize, and/or eliminate the possibility that the driver loses control of the vehicle  100  in the low-speed mode, e.g., due to the high torque output of the motor  108 , the controller  130  may control the battery  132  and/or motor  108  so that motor torque, and/or torque at the wheel(s)  102 ,  104 , is reduced as speed of the vehicle  100  increases toward the maximum speed. Thus, for example, in the low-speed mode, there is an inverse relationship between speed, e.g., speed of the vehicle  100 , rotational speed of the motor  108 , etc., and torque, e.g., torque output by the motor  108 , torque at the driven rear wheel  104 , etc. The torque output by the motor  108  may be controlled by the controller  130  by controlling the current, voltage, and/or frequency of electrical energy supplied to motor  108  from battery  132 . In the low-speed mode, the controller  130  may control the torque output by the motor  108  and/or the wheel(s)  102 ,  104  in accordance with a characteristic map stored, e.g., in memory  158 , as a stepwise function of speed of the vehicle  100  and/or rotational speed of the motor  108 , as an inverse function of speed of the vehicle  100  and/or rotational speed of the motor  108 , etc. 
     In the low-speed mode, the controller  130  may implement, for example, a PI (proportional-integral), a PID (proportional-integral-derivative), etc., feedback control process and/or may be arranged as and/or may include a PI controller, a PID controller, etc. Moreover, the feedback control mechanism may provide, for example, positive torque, to increase the speed of the vehicle  100 , in the circumstance that the speed of the vehicle  100  is below the speed limit of the low-speed mode and speed increase and/or torque is demanded by the driver, or negative torque, to slow the speed of the vehicle  100 , for example, in the circumstance that the speed of the vehicle  100  exceeds or quickly approaches the speed limit of the low-speed mode. 
     In an exemplary implementation, the speed limit of the vehicle  100  in the low-speed mode may be proportional to the rotational speed of the motor  108 , e.g., measured in RPM of the motor  108 . For example, according to a PI control process, a maximum rotational speed ω max  of motor  108  in the low-speed mode may represent a predetermined value and may be stored in memory  158 . In a first range, e.g., between a zero speed and a predetermined rotational speed threshold ω 1 , which is between zero and ω max  (e.g., 0&lt;ω 1 &lt;ω max ), the controller  130  may control motor  108  to output its maximum available torque. In a second range, e.g., between the predetermined rotational speed threshold on of the motor  108  and the maximum rotational speed ω max  of the motor  108 , the controller  130  may control the motor  108  to reduce its output torque, e.g., according to a linear relationship between, for example, speed and torque, approaching zero torque as the rotational speed of the motor  108  approaches the maximum rotational speed ω max . In the circumstance that the rotational speed of the motor  108  reaches the maximum rotational speed ω max , the output torque of the motor  108  may be reduced to zero, and in the circumstance that the rotational speed of the motor  108  exceeds the maximum rotational speed ω max , e.g., operating the vehicle  100  on an incline, the output torque of the motor  108  may be negative, to decrease the speed of the vehicle  100 . The controller  130  may also increase torque output of the motor  108  based on time spent at or near the maximum permitted torque without reaching the maximum rotational speed ω max  of the motor  108 . According to the foregoing PI control process, in the circumstance that the driver of the vehicle  100  in the low-speed mode operates the throttle/accelerator of the vehicle  100  to demand high and immediate speed, torque, power, etc., the controller  130  controls the motor  108  so that (1) high torque is output by the motor  108  upon initial acceleration, (2) torque output by the motor  108 , and acceleration of the vehicle  100 , decreases as the rotational speed of the motor  108  approaches the maximum rotational speed ω max , and (3) torque output by the motor  108  achieves a steady rotational speed of the motor  108  at the maximum rotational speed ω max . The foregoing PI control process may also be implemented to control speed, torque, acceleration of the vehicle  100  based on a setpoint rotational speed that is dependent on the position of the throttle/accelerator. Therefore, for example, the amount of torque available from the motor  108  to propel the vehicle  100  depends on the operating speed of the vehicle  100  and the maximum permitted speed of the vehicle  100 , e.g., ω max , and maximum torque from the motor  108  is available to propel the vehicle  100  in the circumstance that the operating speed of the vehicle  100  is significantly lower than the maximum permitted speed of the vehicle  100 , e.g., ω max . 
     It should be appreciated that controller  130  may implement the control of the battery  132  and/or motor  108  so that the inverse relationship between torque and speed is achieved or that controller  130  may communicate with one or more additional controller(s), ECU(s), etc., to achieve that inverse relationship. For example, an additional controller, e.g., arranged as a motor controller integrated with or separate from the motor  108 , separate from the controller  130 , etc., may control the motor  108  according to the inverse relationship between torque and speed. That is, the additional controller may control the motor  108  so that torque output by the motor  108  is reduced as the speed of the motor  108  increases, e.g., toward an RPM limit of the motor  108 . The controller  130  may communicate to the additional controller that the low-speed mode is engaged or activated, for example, by communicating to the additional controller an RPM limit of the motor  108  that corresponds to the maximum speed of the vehicle  100 , the maximum rotational speed of the motor  108 , etc., of the low-speed mode. The additional controller, therefore, may implement its, e.g., inverse, torque-speed control based on the RPM limit of the motor  108  communicated to the additional controller by the controller  130 . In other words, the additional controller may perform a torque-speed control based on an RPM limit of the motor  108 , and the controller  130  may communicate, to the additional controller, a low-speed mode RPM limit of the motor  108  so that the additional controller implements its torque-speed control of the motor  108  and/or battery  132  in accordance with the low-speed mode RPM limit communicated to the additional controller by the controller  130 . 
     Additionally or alternatively, the additional controller may be adapted to implement the low-speed mode, so that the controller  130  may communicate to the additional controller that the low-speed mode is engaged or activated, without identifying an RPM limit associated with the low-speed mode, and the additional controller may implement its own low-speed mode control to achieve the inverse torque-speed relationship described above. 
     While vehicle  100  is described as a two-wheeled vehicle, it should be appreciated that vehicle  100  may be arranged as any type of vehicle having an electric powertrain, including a powersports vehicle, a powered two-wheeler, a utility terrain vehicle (UTV), an all-terrain vehicle (ATV), a three-wheeled vehicle, etc.