Patent Publication Number: US-11639182-B2

Title: Haptic function of electric vehicle powertrain

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to and claims the benefit of co-pending U.S. patent application Ser. No. 16/829,627 filed on Mar. 25, 2020, issuing as U.S. Pat. No. 10,906,557, which claims priority to and claims the benefit of U.S. Provisional Patent Application 62/875,408, filed on Jul. 17, 2019, the entire contents of which is hereby incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates to an electric vehicle powertrain. More particularly, this invention relates to haptic feedback provided to a rider of an electric vehicle using a motor as a source of torque for generating the haptic feedback. 
     BACKGROUND 
     Electric powertrains do not naturally provide any indication of a vehicle&#39;s state when propulsion is enabled in the vehicle but torque has not been applied to the wheels. In other words, electric powertrains and power electronics are very quiet and have no tactile feedback to a rider while the vehicle is at rest but the propulsion system is in an active state, similar to an idling state of an internal combustion engine (ICE) vehicle. 
     SUMMARY 
     A haptic function may use existing feedback and actuation channels in electric vehicle powertrain software, an inverter, and electromagnetics of the motor. Motor torque may be modulated and applied at a frequency that vibrates a vehicle without causing a tractive torque (i.e., a vehicle will not move). 
     In software, a torque signal may be scripted with frequency, phase, magnitude, and duration specified by adjustable and/or calibratable parameters to create a haptic feedback feature. Multiple torque signals can be summed together to allow for ample variations of torque character in an output torque command. The haptic feature may be applied when the vehicle speed is below an adjustable threshold (e.g., zero or near to zero mph). 
     In some embodiments, a system generates haptic feedback in an electric vehicle. The system comprises a frame, an energy storage device that is supported by the frame, and at least one wheel rotatably coupled to the frame. Also, a motor assembly is supported by frame, where the motor assembly is configured to receive power from the energy storage device and provide torque to the at least one wheel. A controller comprises an electronic processor that is communicatively coupled to the motor assembly and a memory that is coupled to the electronic processor. The memory stores a torque profile defining an irregular-shaped periodic waveform and a program. The program, when executed by the electronic processor, configures the controller to determine a first operational state of the electric vehicle and transmit a first torque signal to the motor assembly to control the motor assembly. The motor assembly is controlled to transmit first torque levels to the at least one wheel to propel the electric vehicle. Levels of the first torque signal are based on the first operational state of the electric vehicle. The controller further determines a second operational state of the electric vehicle and transmits a second torque signal to the motor assembly to control the motor assembly. The motor assembly is controlled to transmit second torque levels to the at least one wheel to generate haptic feedback. Levels of the second torque signal are based on the second operational state of the electric vehicle and the torque profile defining the irregular-shaped periodic waveform stored in the memory. 
     In some embodiments, a method generates haptic feedback in an electric vehicle. The method comprises storing in a memory a torque profile defining an irregular-shaped periodic wave form and a program executable by an electronic processor. The electronic processor is coupled to a motor assembly supported by a frame of the electric vehicle. The motor assembly is configured to receive power from an energy storage device of the electric vehicle and provide torque to at least one wheel rotatably coupled to the frame. The program, when executed by the electronic processor, configures a controller of the electric vehicle to determine a first operational state of the electric vehicle and transmit a first torque signal to the motor assembly. The motor assembly transmits first torque levels to the at least one wheel to propel the electric vehicle. Levels of the first torque signal are based on the first operational state of the electric vehicle. The controller is further configured to determine a second operational state of the electric vehicle and transmit a second torque signal to the motor assembly to control the motor assembly to transmit second torque levels to the at least one wheel to generate haptic feedback. Levels of the second torque signal are based on the second operational state of the electric vehicle and the torque profile defining the irregular-shaped periodic waveform stored in the memory. 
     In some embodiments, an electric vehicle comprises a frame, a wheel rotatably coupled to the frame, an energy storage device, and a motor supported by the frame. The motor is configured to convert power from the energy storage device for transmission to the wheel. A controller comprises an electronic processor that is coupled to a memory. The memory stores a program that when executed by the electronic processor configures the controller to control the motor, while coupled to the wheel, to produce a first torque that is capable of propelling the electric vehicle. The controller is further configured to control the motor, while coupled to the wheel, to produce a second torque that generates haptic feedback via the wheel. A temporal pattern of the haptic feedback is an irregular-shaped periodic wave form. 
     Other features and aspects of the invention will become apparent by consideration of the following detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    illustrates an electric vehicle in the form of a motorcycle, in accordance with some embodiments. 
         FIG.  2    is a schematic block diagram illustrating the electric vehicle of  FIG.  1   , in accordance with some embodiments. 
         FIG.  3    illustrates a sinusoid signal based on a torque profile described in Table 1, in accordance with some embodiments. 
         FIG.  4    illustrates a triangle signal based on a torque profile using the same frequency as the signal of  FIG.  3   , in accordance with some embodiments. 
         FIG.  5    illustrates an example of a torque signal with a heartbeat rhythm, which is based on a selectable torque profile for generating haptic feedback in an electric vehicle, in accordance with some embodiments. 
         FIG.  6    illustrates a flow chart for a method of activating a haptic feedback function in an electric vehicle, in accordance with some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. 
     Haptic feedback is provided in an electric vehicle using torque produced by a motor and a power controller that are also used for vehicle propulsion. In some embodiments, the motor provides the haptic feedback while the electric vehicle is running and stationary, in other words, when the electric vehicle is “at idle.” The haptic function can be activated using software logic of a torque controller such that a torque profile may be applied to the motor when the vehicle is idle. The idle state may be detected when the electric vehicle is in the run state, a start switch for the vehicle has been actuated, and vehicle speed and applied torque are below calibratable thresholds. By setting these parameters appropriately in a vehicle, the haptic function is active when the vehicle is running, but not moving or applying enough wheel torque to move the vehicle forward over time. Threshold values for distinguishing between an idle state and a drive state (e.g., applying enough wheel torque to propel the vehicle), may depend on the type of vehicle platform, or individual vehicle characteristics (e.g., the weight of the vehicle). In some embodiments, other thresholds for speed and/or torque may be configured for determining when to apply haptic feedback while the vehicle is in a drive state, or moving (e.g., haptic feedback may be applied from 0-30 miles per hour). Moreover, in some embodiments, speed and/or wheel torque thresholds may not be utilized. For example, the haptic feedback may be applied at any speed or anytime while the vehicle is running (e.g., idle state and drive state). 
     A haptic feedback torque profile includes a series of discrete torque commands that may be repeated over time, for example, while the vehicle is in the idle state. The haptic feedback torque profile is defined by software executed by an electronic processor of the torque controller. The scripted torque commands configure the torque controller to create a repeating wave shape with a net torque result of zero thereby using the vehicle&#39;s traction motor as an actuator that produces a noticeable feeling at the rider interface points (i.e., haptic feedback). 
     The haptic feedback torque profile is defined according to an array of values, and torque commands are scripted with respect to time based on the torque profile. The time period that the profile is repeated over is calibratable to set a frequency for the delivered profile. In some embodiments, there are multiple selectable haptic feedback torque profiles provided and time period calibrations that allow for multiple unique output wave shapes with different amplitudes and frequencies. 
       FIGS.  1  and  2    illustrate an electric vehicle in the form of a motorcycle system  100 . The motorcycle system  100  includes a frame  14 , a swing arm  18  that is pivotally coupled to a rear portion of the frame  14 , and a front fork  22  that is rotatably coupled to a front portion of the frame  14  at a steering head  26 . A rear wheel  30  is coupled to the swing arm  18 , and a front wheel  34  is coupled to the front fork  22 . The rear wheel  30  and the front wheel  34  support the frame  14  for movement along the ground. A straddle seat  42  overlies at least a portion of the frame  14  for supporting at least one rider. The motorcycle system  100  includes handlebars  46  coupled to the front fork  22  via the steering head  26  for steering the front wheel  34 . Various controls and indicators for operating the motorcycle system  100  may be located on the handlebars  46 . For example, a start button, a key input, and/or another type of mechanism for activating a start switch  222  in the motorcycle system  100  may be located on or near the handle bars  46 . Also, a throttle mechanism  224  for generating a demand signal for torque to the rear wheel  30  may be disposed on the handle bars  46 . The motorcycle system  100  may be referred to as a motorcycle  100 , a system  100 , or an electric vehicle  100 . A user interface  228  for controlling or configuring the motorcycle system  100  may be located on the handle bars  46  or in another location of the motorcycle system. 
     The motorcycle  100  further includes a battery assembly  110 , a motor assembly  120 , a gear assembly  130 , a drive sprocket  131 , a drive belt  132  (located under a belt guard), and a rear wheel sprocket  134  of the rear wheel  30 . The motor assembly  110  and the gear assembly  130  together may be referred to as a drive assembly  202 . The battery assembly  110  may be referred to as an energy storage device. Although illustrated and described as having a belt final drive, the motorcycle  100  in alternate constructions includes a chain final drive or shaft drive to the rear wheel  30 . Also, depending on the configuration and sizing of the motor assembly  120  and the performance envelope of the motorcycle  100 , the gear assembly  130  may be eliminated. In some constructions, the motor assembly  120  drives the drive belt  132 , or other final drive member, directly. 
     The swing arm  18  is pivotably mounted to the motorcycle  100  about a pivot shaft. The pivotable swing arm  18  allows the rear wheel  30  to swing up and down with respect to the frame  14 . The swing arm  18  couples to the rear wheel  30  about a rear wheel axle (not shown), which is fixed with respect to the swing arm  18 . The rear wheel sprocket  134  is mounted on and fixed for rotation with the rear wheel axle, such that the rear wheel sprocket  134  is only moveable in a rotational direction. The rear wheel sprocket  134  is positioned within a drive line and rotates with the wheel  30  in response to movement of the belt  132 . 
     The drive sprocket  131  forms the output of the gear assembly  130  and is coupled to the rear wheel  30  via the belt  132  and the rear wheel sprocket  134 . The belt  132  engages and wraps partially around each of the drive sprocket  131  and the rear wheel sprocket  134 . Upstream of the drive sprocket  131 , the gear assembly  130  includes at least a pair of meshed gears configured to change an input rotation speed by a factor less than 1 and increase torque by a factor greater than 1. The drive sprocket  131  engages the belt  132  and transmits torque from the motor assembly  120  to the rear wheel sprocket  134  via the belt  132 . Thereby, the motorcycle  100  is propelled forward when the applied torque is great enough to cause traction between the rear wheel  30  and the road and inertia is overcome. The battery assembly  110  is electrically coupled to the motor assembly  120  for powering the motor assembly  120 . Although the battery assembly  110 , the motor assembly  120 , and the gear assembly  130  are described herein in the context of the motorcycle  100 , it should be understood that the battery assembly  110 , the motor assembly  120 , and the gear assembly  130  could be used on other electric vehicles, such as automobiles, all-terrain vehicles, and the like for use in providing the haptic feedback to a rider. 
     The motor assembly  120  includes a motor  74  that may be an AC induction motor, and an inverter  226  that comprises power electronics (not shown) for supplying electromagnetic current to windings of the motor  74  to generate torque. The motor  74  may be referred to as the traction motor  74 . The inverter  226  may convert DC power from the battery assembly  110  to AC power to be supplied to the motor  74  for control of the operation of the motor. The inverter  226  includes one or more circuit boards (not shown) that connect switching electronics (e.g., IGBTs, MOSFETS, or the like) for supplying battery power to the motor  74 . In some embodiments, the motor  74  may be a DC motor, such that inverter function circuitry may be omitted in the circuit board. The one or more circuit boards of the inverter  226  may also include other electronic components that control operation of the motor  74  and generate the haptic feedback. 
     The motorcycle  100  may include one or more sensors  220  for determining an operational state of the motorcycle  100 . For example, the sensors may detect when the motorcycle  100  is in an idle state or in a drive state. The drive state may be indicated when the motorcycle  100  is moving and/or when torque is being applied to the gear assembly  130  or the rear wheel  30  for propelling the motorcycle  100  forward. The one or more sensors may be communicatively coupled to a controller  210  and provide sensor information to the controller  210 . The one or more sensors  220  may include, for example, a movement sensor such as a wheel speed sensor or an accelerometer configured to sense movement of the motorcycle  100 , a motor encoder for sensing rotation of a shaft in the motor  74 , a drive shaft rotation sensor, a power converter sensor configured to sense voltage in the inverter  226 , a throttle position sensor configured to sense a position of the throttle  224 , a motor voltage sensor configured to sense a voltage across the motor  74 , a motor current sensor configured to sense a current flow through the motor  74 , a motor rotational sensor configured to sense rotation of the motor  74 , a wheel rotation sensor configured to sense rotation of the front wheel  30  and/or the rear wheel  34 . 
     The motorcycle  100  also includes the controller  210 . The controller  210  may be communicatively coupled to, among other things, the battery  110 , the inverter  226 , the motor  74 , and/or the sensors  220 . The controller  210  controls operation of the motor  74  to provide torque for propelling the motorcycle  100  and for providing haptic feedback to a rider. The controller  210  may be referred to as a torque controller or a motor controller, for example. The controller  210  includes one or more integrated circuits, integrated circuit components, analog circuits, and/or analog circuit components. The controller  210  comprises an electronic processor  212 , a memory  214 , and a gate driver  216 . The memory  214  may comprise a non-transitory computer readable or electronic processor readable memory such as a read only memory (ROM) and/or random access memory (RAM). The electronic processor  212  executes a program to control the operation of the drive assembly  202  where power from the battery  110  is provided to windings of the motor  74 . The electronic processor  212  may include a microprocessor, a programmed logic controller (PLC), a programmable gate array (PGA) such as a field programmable gate array (FPGS), an application specific integrated circuit (ASIC), and/or another microcontroller device. The memory  214  is capable of storing a program including electronic processor executable instructions and/or data that configures the controller  210  to implement functions of the motorcycle  100 , such as delivering torque to the rear wheel sprocket  134 . The memory  214  may store one or more torque profiles for generating haptic feedback using the application of torque to the gear assembly  130  by the motor  74 . The gate driver  216  is communicatively coupled to the inverter  226  for driving switches (e.g., MOSFETs, IGBTs, not shown) of the inverter  226 . The gate driver  216  may transmit drive signals (e.g., pulse width modulation (PWM) gate drive signals) to the inverter  226  for driving the switches that provide the power to the motor  74  from the battery  110 . Alternatively or in addition, controller  210  logic may be implemented in an analog circuit. 
     The motorcycle  100  may include a user interface  228  that allows a user to interact with the motorcycle  100  (e.g., the controller  210 ) to control various operations or configurations of the motorcycle. In some embodiments, the user interface  228  includes a display screen that may have a touch screen functionality for user input (e.g., with a graphical user interface). The user interface may include physical control mechanisms such as buttons, sliders, or knobs, or switches for user input. Moreover, the user interface  228  may include an infotainment system. The motorcycle  100  may include one or more communication interfaces  238 . For example, the communication interface may be configured to receive a cable or wire input to enable communication with the electronic controller  210  and/or the memory  214 . In some embodiments, the communication interface includes a wireless transceiver for communication to and/or from the controller  210 . For example, a user device (e.g., smart phone, laptop, etc.) may communicate wirelessly with the controller  210  via a wireless network (e.g. cellular, WiFi, Bluetooth, etc.). In some embodiments, the user interface  228  and/or the communication interface  238  may be utilized to configure parameters and/or software in the controller  210  and/or the memory  214  for controlling haptic feedback in the motorcycle  100 . 
     The controller  210  may determine a state of the motorcycle  100 , for example, an idle state or a drive state, based on output signals from the one or more sensors  220 , the motor  74 , the inverter  226 , the battery  110 , or based on user input via a mechanical and/or electrical input mechanism of the motorcycle  100 . For example, when user input activates a start switch  222  of the motorcycle  100 , the motorcycle begins running or enters a run state from which the controller  210  may place the motor  74  into an idle state (i.e., standby) where the motor  74  is running but not enough torque is applied to the gear assembly to move the motorcycle forward. A drive state occurs when the motorcycle  100  is powered on and moving, and/or torque is being applied to the rear wheel  30  for propelling the motorcycle  100 . When the throttle  224  is engaged the controller  210  provides power to the motor  74  to propel the motorcycle  100 . The idle state also occurs when the motorcycle  100  stops being propelled forward (i.e., torque is not being applied for the purpose of propelling the motorcycle  100  forward). The controller  210  may determine the state of the motorcycle  100  based on a sensed throttle  224  position, a sensed electrical characteristic of the battery  110 , the inverter  226 , or the motor  74 , a sensed rate of rotation of the motor  74  and/or the wheel  30 , for example. The controller  210  may determine that the motorcycle  100  is in an idle state when the motorcycle  100  is powered on and the torque applied by the motor  74  falls below a specified torque threshold  236  and/or motorcycle speed is below a specified speed threshold  236  that are stored in the memory  214 . 
     When the controller  210  determines that the motorcycle  100  is in the idle state, the gate driver  216  of the controller  210  sends control signals to the inverter  226  circuitry to supply specified energy levels in a specified temporal pattern from the battery  110  to the motor  74 . The motor  74  then generates haptic feedback to a rider of the motorcycle  100  while in a connected state with the gear assembly  130 , the belt  132 , the rear wheel sprocket  134 , and the rear wheel  30 , without propelling the motorcycle  100  substantially forward (e.g., with substantially zero net torque). The levels of applied torque and the temporal pattern of the applied torque for the haptic feedback may be referred to as a torque profile  234 . One or more torque profiles  234  are programmed into the memory  214  and executed by the controller  210 . The memory  214  may store multiple torque profiles  234  (e.g., torque profiles may be pre-loaded in the factory or stored to the memory  214  via the user interface  238  and/or the communication interface  238 ). The torque profiles  234  may be selectable to change the shape, frequency, and/or amplitude of the haptic feedback. The torque profiles may be calibrated or configured by a user for adjusting the frequency or amplitude of an applied haptic feedback signal (e.g., change the period of a repeating signal or select an amplitude multiplier). Torque profile selection parameters  230  and/or haptic feedback calibration parameters  232  may be stored in the memory  214 . In some embodiments, the torque profile selection parameters  230  and/or haptic feedback calibration parameters  232  may be configured via the user interface  228  and/or the communication interface  238  by a user of the motorcycle  100 , a professional at a point of sale, or a manufacturer. For example, a professional at a dealership may connect a cable between a laptop and a bus of the motorcycle  100  to communicate with the controller  210  and/or memory  214 , and use a digital tech service tool on the laptop to select a pre-loaded torque profile stored in the memory  214 , turn haptic feedback on or off, add a torque profile, or update haptic feedback parameters stored in the memory  214 . In another example, a user interface  228  of an infotainment system on the motorcycle  100  or a user interface displayed by a mobile application on a smart phone may provide a graphical user interface that receives user input to select a torque profile, add a torque profile, turn haptic feedback on or off, or select haptic feedback parameters. Different haptic feedback characteristics may selected based on motorcycle platform or user preference, for example. 
     A torque profile  234  may include a series of discrete torque commands that may be repeated over time (e.g., while the motorcycle  100  is in the idle state). The torque profile  234  is defined by software and/or parameters executable by the electronic processor  212  of the controller  210 . The scripted torque commands  234  configure the controller  210  to transmit signals of a repeating wave shape to the motor assembly  120 , or to the inverter  226 , with a net torque result of substantially zero. Thereby, the motorcycle&#39;s motor  74  is used as an actuator that produces a noticeable feeling at the rider interface points (i.e., haptic feedback). As noted above, characteristics of the repeating wave shape (i.e., torque profile) are programmable and the frequency or period of the wave shape (calibration parameters) is configurable based on user input. 
     The torque profile commands  234  are defined according to an array of values where the torque profile commands are scripted with respect to time. A time period for executing commands of a torque profile array is calibratable to establish a desired frequency for repeatedly delivering the profile and thus the haptic feedback to the rider. In some embodiments, there are parameters  230  for selecting from multiple torque profiles  234  and haptic feedback calibration parameters  232  that allow for multiple torque profile period calibrations and multiple selectable unique output wave shapes. In one example, there are two selectable profiles  234  and two period calibrations  232  allowing for two unique output wave shapes and a selected frequency from the two frequencies for each of the output wave shapes. However, the disclosure is not limited in this regard, and any suitable number of haptic feedback torque profiles  234  and/or haptic feedback calibration parameters  232  may be stored in the memory  214 . 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Torque Profile - a 25 point torque profile array 
               
            
           
           
               
               
               
            
               
                   
                 Sample 
                 Torque 
               
               
                   
                   
               
            
           
           
               
               
               
            
               
                   
                 1 
                 0 
               
               
                   
                 2 
                 0.25 
               
               
                   
                 3 
                 0.48 
               
               
                   
                 4 
                 0.58 
               
               
                   
                 5 
                 0.84 
               
               
                   
                 6 
                 0.95 
               
               
                   
                 7 
                 1 
               
               
                   
                 8 
                 0.98 
               
               
                   
                 9 
                 0.91 
               
               
                   
                 10 
                 0.77 
               
               
                   
                 11 
                 0.59 
               
               
                   
                 12 
                 0.37 
               
               
                   
                 13 
                 0.13 
               
               
                   
                 14 
                 0.12 
               
               
                   
                 15 
                 −0.37 
               
               
                   
                 16 
                 −0.59 
               
               
                   
                 17 
                 −0.77 
               
               
                   
                 18 
                 −0.9 
               
               
                   
                 19 
                 −0.98 
               
               
                   
                 20 
                 −1 
               
               
                   
                 21 
                 −0.95 
               
               
                   
                 22 
                 −0.85 
               
               
                   
                 23 
                 −0.69 
               
               
                   
                 24 
                 −0.48 
               
               
                   
                 25 
                 −0.25 
               
               
                   
                   
               
            
           
         
       
     
     Table 1 illustrates an example torque profile with a 25 point array of values for defining a set of torque commands  234 . The torque profile array values may be utilized by the controller  210  to issue commands to the motor assembly  120  to control torque applied to the wheel  30 . The set of torque profile commands  234  may be executed over a calibrated period of time and may be repeated over multiple periods. The duration of application of each torque level in the torque profile array, may be determined by dividing the calibrated period of the torque profile commands by the number of points in the torque array. For example, setting a period of 250 ms for executing commands corresponding to the 25 point torque profile of Table 1, yields a time step between torque points of 10 ms, where 250 ms/25 s samples=10 ms/sample. The time step between torque points of a torque profile may be adjusted according to stored configuration parameters  232  that correspond to the torque profile period divided by the total count of points in the torque profile array. In the above example, each torque setting is held for 10 ms according to a command  234  of the torque controller  210  to the motor assembly  120 . The overall torque array of Table 1 is repeated every profile period of 250 ms based on the state of the motorcycle  100  (e.g., while the motorcycle  100  is in the idle state).  FIG.  3    illustrates a sinusoid with a period of 0.25 s (250 ms), which can be repeated at a frequency of 4 Hz according to the torque profile of Table 1. The torque values in this and other examples given herein may represent motor torque in Newton-meters (N-m). 
     Different and unique torque profiles  234  can be stored in the memory  214 .  FIG.  4    is an example of a 25 point torque array defining a triangle wave and configured with the same haptic feedback calibration parameters  232  as for the sinusoid shown in  FIG.  3    having a torque profile repetition frequency of 4 Hz and a period of 0.25 s. 
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 Heartbeat Torque Profile A 
               
            
           
           
               
               
               
            
               
                   
                 Step 
                 Value 
               
               
                   
                   
               
            
           
           
               
               
               
            
               
                   
                 0 
                 0 
               
               
                   
                 1 
                 1 
               
               
                   
                 2 
                 2 
               
               
                   
                 3 
                 −2 
               
               
                   
                 4 
                 2 
               
               
                   
                 5 
                 0 
               
               
                   
                 6 
                 0 
               
               
                   
                 7 
                 0 
               
               
                   
                 8 
                 0 
               
               
                   
                 9 
                 0 
               
               
                   
                 10 
                 0 
               
               
                   
                 11 
                 0 
               
               
                   
                 12 
                 0 
               
               
                   
                 13 
                 0 
               
               
                   
                 14 
                 0 
               
               
                   
                 15 
                 0 
               
               
                   
                 16 
                 0 
               
               
                   
                 17 
                 0 
               
               
                   
                 18 
                 0 
               
               
                   
                 19 
                 0 
               
               
                   
                 20 
                 0 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 Heartbeat Torque Profile B 
               
            
           
           
               
               
               
            
               
                   
                 Step 
                 Value 
               
               
                   
                   
               
            
           
           
               
               
               
            
               
                   
                 0 
                 0 
               
               
                   
                 1 
                 0 
               
               
                   
                 2 
                 0 
               
               
                   
                 3 
                 0.3 
               
               
                   
                 4 
                 0.6 
               
               
                   
                 5 
                 0.90 
               
               
                   
                 6 
                 1.3 
               
               
                   
                 7 
                 1.3 
               
               
                   
                 8 
                 0.9 
               
               
                   
                 9 
                 0.6 
               
               
                   
                 10 
                 0.3 
               
               
                   
                 11 
                 0 
               
               
                   
                 12 
                 0 
               
               
                   
                 13 
                 −1 
               
               
                   
                 14 
                 −1 
               
               
                   
                 15 
                 −1 
               
               
                   
                 16 
                 −1 
               
               
                   
                 17 
                 −1 
               
               
                   
                 18 
                 −1 
               
               
                   
                 19 
                 0 
               
               
                   
                 20 
                 0 
               
               
                   
                 21 
                 0.3 
               
               
                   
                 22 
                 0.8 
               
               
                   
                 23 
                 1.1 
               
               
                   
                 24 
                 1.6 
               
               
                   
                 25 
                 1.6 
               
               
                   
                 26 
                 0.9 
               
               
                   
                 27 
                 0.6 
               
               
                   
                 28 
                 0.3 
               
               
                   
                 29 
                 0 
               
               
                   
                 30 
                 0 
               
               
                   
                 31 
                 0 
               
               
                   
                 32 
                 0 
               
               
                   
                 33 
                 0 
               
               
                   
                 34 
                 0 
               
               
                   
                 35 
                 0 
               
               
                   
                 36 
                 0 
               
               
                   
                 37 
                 0 
               
               
                   
                 38 
                 0 
               
               
                   
                 39 
                 0 
               
               
                   
                 40 
                 0 
               
               
                   
                 41 
                 0 
               
               
                   
                 42 
                 0 
               
               
                   
                 43 
                 0 
               
               
                   
                 44 
                 0 
               
               
                   
                 45 
                 0 
               
               
                   
                 46 
                 0 
               
               
                   
                 47 
                 0 
               
               
                   
                 48 
                 0 
               
               
                   
                 49 
                 0 
               
               
                   
                 50 
                 0 
               
               
                   
                 51 
                 0 
               
               
                   
                 52 
                 0 
               
               
                   
                 53 
                 0 
               
               
                   
                 54 
                 0 
               
               
                   
                 55 
                 0 
               
               
                   
                 56 
                 0 
               
               
                   
                 57 
                 0 
               
               
                   
                 58 
                 0 
               
               
                   
                 59 
                 0 
               
               
                   
                 60 
                 0 
               
               
                   
                 61 
                 0 
               
               
                   
                 62 
                 0 
               
               
                   
                 63 
                 0 
               
               
                   
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     Tables 2 and 3 represent two torque profiles, A and B, for defining two sets of torque profile commands  234  for generating heartbeat-mimicking haptic feedback to a user via the drive assembly  202  and the rear wheel  30  of  FIGS.  1  and  2   . In other words, the haptic feedback is generated and perceived to mimic the electrical impulse or resulting sound wave of a human heart during a normal cardiac cycle. Each of the heartbeat torque profiles A and B can be used to configure the controller  210  to drive a unique vehicle haptic feedback experience that may be perceived by a rider as having a heartbeat rhythm. In this regard, the controller may transmit PWM signals based on the torque profile. For example, the gate driver  216  may transmit PWM gate drive signals to the inverter  226  for driving the switches that provide current to the motor  74  from the battery  110 . The current provided to the motor  74  may directly determine the torque output by the motor  74 . The heartbeat torque profiles A and B of Tables 2 and 3 each have a different number of steps and represent different torque intensity levels. Torque profile A of Table 1 includes 20 torque intensity steps per period. Torque profile B of Table 2 includes 101 torque intensity steps per period. In general, heartbeat torque profile rhythms or heartbeat haptic feedback are characterized by an irregular-shaped periodic wave form that is repeated. The heartbeat torque profile rhythms may have one or more higher-intensity pulses within a first time duration of a torque profile period and quiet time-duration of a lower or zero level torque intensity within the same period of the torque profile. The quiet time-duration may be referred to as a dead zone of the torque profile period and may have a longer duration than the active portion of the period. This torque profile period for haptic feedback can be repeated during an idle state of the motorcycle  100  to mimic a heartbeat signal. Also, the higher-intensity pulses within the torque profile period are not strong enough to propel the motorcycle  100  forward or change the speed of the motorcycle and instead provide haptic feedback to a rider. Each of the torque profiles A and B of Tables 1 and 2 define one torque profile period that includes two same-sign (e.g., positive) torque intensity pulses during a first time duration followed by zero intensity over a second time duration, which may be longer than the first time duration. The zero intensity time period defines a lull in the haptic feedback, and in other constructions a similar lull may be produced even when the torque intensity is not strictly zero if the torque is insufficient to be perceptible by the rider or is perceptible as only as background vibration. The signal may include a different-sign (e.g., negative) torque intensity pulse, for example, as between the two positive pulses in each of the torque profiles A and B. The two same-sign pulses can be the same intensity or different intensities. The sign of the torque pulses correlate to motor shaft direction, particularly clockwise vs. counter-clockwise.  FIG.  5    illustrates an example of one period of a heartbeat rhythm torque signal for generating haptic feedback in the motorcycle  100 . The signal of  FIG.  5    is based on a heartbeat torque profile similar to the torque profile B of Table 3. The period of the heartbeat haptic feedback signal in  FIG.  5    shows torque intensity over a range of  101  time units corresponding to one period of the torque profile. The signal shown in  FIG.  5    may be adjusted as to period length and may be repeated based on the state of the motorcycle  100 . Other signal shapes that mimic the irregular rhythm of a heartbeat may be utilized. 
     In some embodiments, the haptic feedback may be activated while the motorcycle  100  is in a drive state based on a selected torque profile. For example, a haptic feedback torque profile may be overlaid onto a torque profile that is generated based on throttle position (i.e., used for propelling the motorcycle) to provide haptic feedback while the motorcycle is being driven. In some embodiments, the controller  210  may be configured to apply a first haptic feedback torque profile  234  when the motorcycle  100  is in an idle state and a different haptic feedback torque profile when the motorcycle is in a drive state. In addition or in the alternative, the controller  210  may be configured to utilize a first calibration parameter  232  for controlling the period length of a selected torque profile when the motorcycle  100  is in an idle state and a second or varied calibration parameter  232  during a drive state. Moreover, the controller  232  may be configured to adjust or change one or both of the selected torque profile  234  (i.e., change wave shape) and the haptic feedback calibration parameters  232  (i.e., adjust a torque profile period length) depending on a level of torque being applied to the drive assembly  202  for the propulsion of the motorcycle during a drive state. For example, the controller  210  may generate a change in a haptic feedback torque control signal to the drive assembly  202  when the level of applied torque exceeds or falls below a torque threshold during a drive state. 
     Torque signals may be summed together to create a single input to a torque control program. For example, the torque profile may be summed with a torque request from the rider such that the haptic profile is a repeating irregular wave superimposed on the torque request from the rider. In some cases, the haptic profile may be included in the summation only when the rider torque request is below a calibratable threshold representing “vehicle idle.” 
     The haptic torque profile is calibratable by assigning discrete torque steps in the sequential array. The calibrator selects the array inputs and enters them to a calibration file which may be written to the software memory at the time of manufacturing or software update. 
     As noted above, the memory  214  stores torque profile selection parameters  230  for selecting torque profile commands from multiple sets of selectable torque profiles commands  234 . Also, the memory  214  stores haptic feedback calibration parameters  232  for configuring a period or frequency of the selected torque profile. Thus, multiple selectable unique output wave shapes and selectable torque profile periods or frequencies are available. In one example embodiment, two selectable profiles  234  are stored in the memory  214  and period calibrations  232  allow for two unique output wave shapes. In some embodiments, adjustable settings for selecting and calibrating torque profile commands for haptic feedback may be configured by a user, a manufacturer, or at a point of sale. For example, the manufacturer adjustable settings may include:
         1) Settings that are configurable using a 2 bit diagnostic setting with the options of:
           a. Disable global haptic feedback function   b. Enable profile A   c. Enable profile B   
           2) Configurable torque profile array that is set by calibration of the definition of the torque profile A or the torque profile B.   3) Configurable frequencies that are set for the establishing a profile period A or a profile period B.   4) Haptic function active and inactive during run time is set by calibration of a motor torque threshold. Function active occurs below the motor torque threshold where the motor torque is torque that produces vehicle motion.   5) Haptic function active and inactive during run time is calibratable for a delivered motor-speed threshold. Function is active below the motor-speed threshold.       

       FIG.  6    illustrates a flow chart for a method of activating a haptic feedback function in the motorcycle  100 . In step  610 , the controller  210  is configured according to a haptic feedback torque profile  234 . One or more haptic feedback torque profiles may be preloaded in the vehicle. The haptic feedback torque profile and/or haptic feedback calibration parameters  232  for torque profile period or frequency may be selected via a user interface. Also, one or more thresholds  236  such as a wheel torque threshold  236  and/or a motor speed threshold  236  may be configured via a user interface for determining when to activate and/or deactivate the haptic feedback function (e.g., activate haptic feedback during an idle state and/or a drive state, or cut-off haptic feedback at a specified speed). 
     In step  612 , the controller  210  may read a sensor or receive a signal indicating that a start switch  222  has been activated. In instances when the start switch  222  has been activated, the method may proceed to step  614 . In instances when the start switch  222  has not been activated, the method returns to step  612 . 
     In step  614 , the controller  210  may read a sensor  220  or receive a signal from the battery  110 , the inverter  226 , and/or the motor  74 , indicating that the motorcycle  100  is in a run state and ready to receive torque commands from the controller  210 . In instances when the system  100  is in a run state, the method may proceed to step  616 . In instances when the system  100  is not in a run state, the method may proceed to step  612 . 
     In step  616 , the controller  210  may read a sensor  220  or receive a signal from the battery  110 , the inverter  226 , and/or the motor  74  indicating that a speed is below a first specified threshold of the thresholds  236 . In instances when the speed is below the first specified threshold  236 , the method may proceed to step  618 . In instances when the speed is not below the first specified threshold  236 , the method may proceed to step  612 . In some embodiments, the first specified threshold for speed may be calibrated to a level of speed that indicates the vehicle is in an idle state (e.g., substantially zero or near zero, for example, less than 2 miles per hour) such that the haptic feedback is applied only when the vehicle is in an idle state. In some embodiments, the first specified threshold for speed may be set to a level (e.g., 30 miles per hour) to indicate that the haptic feedback should be applied during the idle state and any time the vehicle is driven under 30 miles per hour. In some embodiments, the first specified threshold for speed may be unlimited or disabled such that the vehicle speed is always below the threshold such that haptic feedback may be applied at any speed. 
     In step  618 , the controller  210  may read a sensor  220 , the throttle  224 , or receive a signal from the motor  110 , the inverter  226 , and/or the motor  74  indicating that an applied torque is below a second specified threshold of the thresholds  236 . In instances when the applied torque is below the second specified threshold  236 , the method may proceed to step  620 . In instances when the applied torque is not below the first specified threshold  236 , the method may proceed to step  612 . In some embodiments, the second specified threshold for wheel torque may be calibrated to a level that indicates the vehicle is in an idle state (e.g., substantially zero torque or near zero torque) such that the haptic feedback is applied only when the vehicle is in an idle state. In some embodiments, the second specified threshold for torque may be set to a level (e.g., 7 Nm) to indicate that the haptic feedback should be applied during the idle state and any time the vehicle is driven with less than 7 Nm of torque. In some embodiments, the second specified threshold for torque may be unlimited or disabled such that the wheel torque is always below the threshold such that haptic feedback may be applied at any level of wheel torque. 
     In step  620 , the controller  210  may be configured to activate the haptic feedback function and transmit haptic feedback torque control signals to the inverter  222  from the gate driver  216  according to the selected haptic feedback torque profile  234 . The selected haptic feedback calibration parameters  232  may be utilized for applying a torque profile period or frequency in the haptic feedback. 
     In some embodiments, based on the haptic feedback, a rider of the electric motorcycle  100  may perceive that the motorcycle is running in an idle state. In other embodiments, the haptic feedback may be applied while the motorcycle is being driven. The rhythm of the haptic feedback activated in step  620  may mimic a heartbeat signal based on the selected torque profile  234 . 
     Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects of the invention as described.