JP2024107349A - Two-wheeled vehicle with virtual brake and virtual clutch - Google Patents

Abstract

To provide an improved method of operating an electric motor of a vehicle.SOLUTION: The method comprises: detecting a position of a first control included in the vehicle; detecting a position of a second control included in the vehicle; associating the detected position of the first control with a first requested torque; associating the position of the second control with a second requested torque; determining, with an electronic control unit, a torque command based on the first requested torque and the second requested torque, by multiplying the first requested torque and the second requested torque; and transmitting the torque command to an electric motor included in the vehicle.SELECTED DRAWING: Figure 5

Description

This application claims priority to U.S. Provisional Application No. 62/793,127, filed January 16, 2019, the entire contents of which are incorporated herein by reference.

The embodiments described herein relate to vehicles, and more particularly to two-wheeled vehicles that use an electric powertrain with a regenerative braking system to supplement or replace mechanical friction brakes, such as hydraulic brakes, and simulate a clutch or a clutch and brake combination. Thus, the embodiments described herein can provide a virtual brake or clutch that simulates a mechanical brake or clutch.

Mechanical friction brakes, such as hydraulic brakes, add cost and weight, which impacts the performance of vehicles, especially electric vehicles, such as electric motorcycles. Additionally, mechanical friction brakes dissipate kinetic energy that could otherwise be used to charge a power storage unit included in the vehicle, and dissipation of kinetic energy can limit the range and operation of the electric vehicle. Mechanical clutches also add cost and weight to two-wheeled vehicles.

Accordingly, the embodiments described herein provide methods and systems for regenerative braking of at least one wheel of a vehicle, such as an electric motorcycle. In some embodiments, regenerative braking is used as the sole mechanism for braking a wheel of the vehicle, such as the rear wheel of a two-wheeled vehicle. Replacing rear hydraulic brakes with regenerative braking reduces the cost, weight and complexity of the vehicle, and impacts vehicle performance as discussed above.

For example, one embodiment provides a two-wheeled vehicle. The two-wheeled vehicle includes an electric motor, a wheel drivingly coupled to the electric motor for propelling the two-wheeled vehicle, a drive torque control movable between a first plurality of positions, and a regenerative brake control movable between a second plurality of positions. The vehicle also includes an electronic control unit. The electronic control unit is configured to: detect a position of the drive torque control from the first plurality of positions; map the detected position of the drive torque control to a requested drive torque; detect a position of the regenerative brake control from the second plurality of positions; map the position of the regenerative brake control to a requested brake torque; sum the requested drive torque and the requested brake torque to determine a torque command; and communicate the torque command to the electric motor. In some embodiments, regenerative braking provided via the electric motor based on the torque command is the only mechanism provided for braking the wheels.

Another embodiment provides a method for operating an electric motor of a two-wheeled vehicle. The method includes the steps of detecting a position of a first control included in the two-wheeled vehicle, the first control controlling a drive torque of the two-wheeled vehicle, detecting a position of a second control included in the two-wheeled vehicle, mapping the detected position of the first control to a first requested torque, mapping the position of the second control to a second requested torque, determining a torque command using an electronic control unit based on the first requested torque and the second requested torque, and transmitting the torque command to an electric motor included in the vehicle.

Yet another embodiment provides a system for operating an electric motor of a two-wheeled vehicle. The system includes at least one electronic control unit included in the two-wheeled vehicle. The at least one electronic control unit is configured to: detect a position of a first control device included in the vehicle and controlling a drive torque of the two-wheeled vehicle; detect a position of a second control device included in the two-wheeled vehicle; map the detected position of the first control device to a first requested torque; map the position of the second control device to a second requested torque; determine a torque command based on the first requested torque and the second requested torque; and transmit the torque command to an electric motor included in the vehicle.

Other features and aspects of the present invention will become apparent from consideration of the following detailed description and accompanying drawings.

FIG. 1 is a perspective view of a two-wheeled vehicle according to one embodiment. FIG. 2 is a right side view of the two-wheeled vehicle of FIG. FIG. 3 is a left side view of the two-wheeled vehicle of FIG. FIG. 4 illustrates the two-wheeled vehicle of FIG. 1 including a twist grip and regenerative braking control device according to an embodiment. FIG. 5 is a flow chart illustrating a method of operating the electric motor of the two-wheeled vehicle of FIG. 1 in accordance with one embodiment. FIG. 6 illustrates a schematic of an input process for generating a requested torque based on position of a regenerative braking control device included in the two-wheeled vehicle of FIG. 1 according to one embodiment. FIG. 7 illustrates a schematic of an input process for generating a virtual brake and a virtual clutch for the two-wheeled vehicle of FIG. 1 according to one embodiment. FIG. 8 is a schematic diagram illustrating a process flow for virtual braking and virtual clutching according to one embodiment.

One or more embodiments are described in the following description and illustrated in the accompanying drawings. These embodiments are not limited to the specific details described herein and may be modified in various ways. In addition, there may be other embodiments not described herein. Also, functions described herein as being performed by one component may be performed in a distributed manner by multiple components. Similarly, functions described herein as being performed by multiple components may be aggregated and performed by a single component. Similarly, components described as performing a particular function may also perform additional functions not described herein. For example, a device or structure that is "configured" in a particular way may be configured in at least that way, but may also be configured in a way that is not described. Furthermore, some embodiments described herein may include one or more electronic processors configured to perform the described functions (or portions thereof) by executing instructions stored in a non-transitory computer-readable medium. Similarly, embodiments described herein may be implemented as a non-transitory computer-readable medium that stores instructions executable by one or more electronic processors to perform the described functions. As used herein, "non-transitory computer-readable medium" includes all computer-readable media, but does not consist of a transitory propagating signal. Thus, a non-transitory computer readable medium may include, for example, a hard disk, a CD-ROM, an optical storage device, a magnetic storage device, a ROM (read only memory), a RAM (random access memory), a register memory, a processor cache, or any combination thereof.

In addition, the expressions and terms used herein are for explanatory purposes and should not be construed as limiting. For example, the use of "include," "contain," "included," "having," and variations thereof herein means including additional items in addition to the items listed and their equivalents. The terms "connected" and "coupled" are used broadly and include both direct and indirect connections and couplings. Furthermore, "connected" and "coupled" are not limited to physical or mechanical connections or couplings, but can include electrical connections or couplings, whether direct or indirect. In addition, electronic communications and notices may be made using wired connections, wireless connections, or a combination thereof, and may be transmitted directly or through one or more intermediate devices over various types of networks, communication channels, and connections. Furthermore, relationship terms such as first and second, above and below, etc. are used herein only to distinguish one entity or operation from another entity or operation, and are not meant to actually require or imply such a relationship or order between such entities or operations.

FIG. 1 illustrates a two-wheeled vehicle 20 according to an embodiment. It should be noted that the systems and methods described herein may be applicable to any type of two-wheeled vehicle (e.g., motorcycles, mopeds, electric bicycles, etc.). The two-wheeled vehicle 20 includes a front wheel 22 and a rear wheel 24 (e.g., one front wheel 22 and one rear wheel 24 aligned with the one front wheel 22 to define a trajectory). The vehicle 20 includes a frame structure having a main frame 28. A front fork 32 supports the front wheel 22 forward of the main frame 28. The front fork 32 is rotatably connected to a head tube 36 of the main frame 28. A handlebar 40 is connected to the front fork 32 so that a driver can control the orientation of the front fork 32 and the front wheel 22. A rear swingarm 44 supports the rear wheel 24 to rotate within the rear swingarm 44. The rear swingarm 44 allows both the rear wheel 24 and the swingarm 44 to have pivoting suspension movements about axis A relative to the main frame 28. In addition to pivotal support at axis A, the swingarm 44 is connected to the main frame 28 via a shock absorber unit 46 (e.g., including a coil spring and a hydraulic damper). The vehicle 20 further includes at least one seat 48 (e.g., a saddle seat for an operator and optionally a rear passenger) and at least one set of foot supports 50 (e.g., laterally extending foot pegs).

As shown, the vehicle 20 is an electric motorcycle powered by an electric powertrain including a power storage 54 (e.g., a battery pack) and an electric motor 58 electrically coupled to the power storage 54, where stored electrical energy from the power storage 54 is converted into rotational kinetic energy to drive the vehicle 20. As shown, the electric motor 58 powers the rear wheel 24 via an endless drive member 62 (e.g., a belt or chain) in the form of a toroid wrapped around a drive sprocket 66 and a driven sprocket 68 that is fixedly secured to the rear wheel 24. The drive sprocket 66 that drives the endless drive member 62 is fixed for rotation with the output shaft 70 of the electric motor 58 about axis A. As such, the vehicle 20 is not provided with a multi-speed transmission between the electric motor 58 and the drive sprocket 66, nor is it provided with a gearbox. In some embodiments, the electric motor 58 includes a high pole count motor having a high torque density.

The vehicle 20 uses regenerative braking to brake one or both of the wheels 22, 24. Specifically, the vehicle 20 uses the regenerative capabilities of the electric motor 58 to supplement or replace mechanical friction brakes (e.g., hydraulic brakes) for one or both of the wheels 22, 24. For example, as shown in FIG. 4, the handlebar 40 of the vehicle 20 includes a braking control for each wheel 22, 24. Specifically, as shown, the vehicle 20 includes a conventional front brake lever 70 on the right side of the handlebar 40 to control braking of the front wheel 22 (via a mechanical friction brake, such as a hydraulic brake) and a control device 72 on the left side of the handlebar 40 to control regenerative braking of the rear wheel 24. As described below, in some embodiments, the control device 72 operates as a regenerative braking control device. The driver of the vehicle 20 requests various amounts of negative torque from the electric powertrain using the controller 72, and applies the requested torque to stop or slow the vehicle 20 (i.e., to stop or slow the rear wheels 24). During braking of the rear wheels 24, braking energy is captured and returned to the power storage 54, rather than being dissipated as heat through application of mechanical friction brakes (e.g., brake caliper/rotor friction). As such, in some embodiments, no mechanical friction brakes are provided for the rear wheels 24, reducing the cost, weight, and complexity of the vehicle 20. For example, in some embodiments, the electric powertrain provides at least the same amount of braking force as conventional hydraulic brakes provided on motorcycles, and the cost and weight associated with more advanced mechanical braking systems, such as advanced hydraulic brakes, are avoided.

As shown in FIG. 4, in some embodiments, the control device 72 includes a pivotable lever that the driver pulls toward the handlebar 40 to brake the rear wheels 24. The amount or degree to which the lever is pulled or pivoted is equal to the amount of braking the driver requires. Thus, in some embodiments, the control device 72 allows the driver to continuously vary the amount of regenerative braking based on how much the driver pulls the lever toward the handlebar 40. If the driver does not pull the lever, the lever is biased (with a spring or similar biasing member) via the control device 72 to a home position where no braking of the rear wheels 24 is required. Note that in some embodiments, the control device 72 may include a different type of actuator than the pivot lever shown in FIG. 4. Additionally, in some embodiments, the control device 72 may be located elsewhere on the vehicle 20 other than the handlebar 40. For example, in some embodiments, the control device 72 includes a foot pedal instead of the manual lever shown in FIG. 4.

The amount of regenerative braking applied to the rear wheels 24 may be controlled based on a combination of inputs including inputs received through the controller 72 and inputs received through a rotating twist grip coupled to the handlebar 40. For example, as shown in FIG. 4, the vehicle 20 includes a twist grip 74 that is rotatable through a plurality of positions. A twist grip sensor included with the vehicle 20 is configured to detect the position of the twist grip 74, for example, via a Hall effect sensor, a rotary encoder, or the like. While the twist grip 74 is shown in FIG. 4 as being located on the right side of the handlebar 40, in other embodiments, the twist grip 74 may be located on the left side of the handlebar 40. Also, in some embodiments, a different type of actuator (e.g., a pedal, a pivot lever, etc.) may be used in place of the illustrated rotatable twist grip 74 to receive input from the driver regarding the drive torque requested for the vehicle 20 (i.e., the rear wheels 24). Such actuators may be generally referred to herein as drive torque controllers.

The detected position of the twist grip 74 is mapped to a requested drive torque. In some embodiments, the mapping between the current position of the twist grip 74 and the associated torque request may also be based on the current speed of the vehicle 20, which may be determined based on an operating parameter of the electric motor 58, such as revolutions per minute (RPM). For example, in some embodiments, a two-dimensional look-up table may be used to map the current twist grip position and current speed to a requested drive torque.

Also, in some embodiments, the vehicle 20 may be operated in one of multiple ride modes. The multiple ride modes may be selected by manual driver selection, automatic selection based on the operating conditions of the vehicle 20, or both. Each ride mode may provide a different operation of the vehicle 20, such as by providing maximum speed or acceleration, providing efficient energy usage, etc. Thus, in these embodiments, a specific two-dimensional table for the currently active ride mode may be used to map the twist grip 74 position and current speed to the requested drive torque.

A second (negative) torque demand is generated based on the position of the controller 72, independent of the torque demand determined based on the position of the twist grip 74. This mapping may be performed using an equation or a one-dimensional look-up table. For example, the position of the controller 72 is sensed by a control sensor (including, for example, optical, mechanical, electrical, etc.) similar to the twist grip 74, and the sensed position is mapped to a required braking torque. In some embodiments, if an equation is used to perform the mapping, the equation may include determining a percentage of the controller 72 actuation, for example, by dividing the sensed position of the controller 72 by a predetermined maximum position. In such an embodiment, the percentage of the controller 72 actuation may be multiplied by a maximum amount of regenerative braking torque available to calculate a required braking torque (N/m). In some embodiments, the maximum position of the controller 72, the maximum available braking torque, or both may be defined in memory or software so that the actuation of the controller 72 may be configured for different motorcycles, drivers, driving conditions, etc. In some embodiments, the requested regenerative braking torque defined by the position of the controller 72 may vary based on the currently selected ride mode, similar to the twist grip 74 described above. However, in other embodiments, the amount of regenerative braking requested through the controller 72 remains the same regardless of the currently selected ride mode.

In some embodiments, the requested drive torque defined by the position (rotation) of the twist grip 74 is summed with the requested braking torque defined by the position of the controller 72 to determine a torque command for the electric motor 58 that is sent to the motor controller for the electric motor 58. The generated torque command thus represents a blended command consisting of any amount of drive torque requested by the driver via the twist grip 74 and any amount of braking torque requested by the driver via the controller 72. If the torque command is negative, the electric motor 58 regeneratively brakes the rear wheels 24 and energy captured during regenerative braking may be stored in the power storage 54. If the torque command is positive, the electric motor 58 drives the rear wheels 24 to move the vehicle 20 forward. However, the amount of drive torque represented by the torque command may be less than the previous torque command, resulting in a deceleration of the vehicle 20 even though the torque command is positive.

In some embodiments, torque limits may be applied to the summed torque value or to the individual torque values included in the sum before sending a torque command to the motor controller based on the sum to keep the torque command sent to the motor controller within the operating limits of the electric powertrain to provide advanced braking functions such as traction control or anti-lock braking. In other embodiments, the motor controller or other components included in the vehicle 20 may further process the torque request before it is executed via the electric motor 58.

The requested drive torque, as defined by the position of the twist grip 74, can be positive or negative. That is, the torque request can request traction or regenerative braking. For example, the torque request, as defined by the position of the twist grip 74, can include negative torque (regenerative braking) to provide cost savings to the vehicle 20. Thus, as used herein, the "requested drive torque" (as defined based on the position of the twist grip 74) can be positive or negative. However, there can be negative torque requested based on the position of the twist grip 74 in addition to or independent of any regenerative braking control (negative torque) requested via the controller 72.

FIG. 5 is a flow chart illustrating a method 80 for generating a virtual brake, e.g., a regenerative braking torque, for an electric motor 58 of a vehicle 20 according to an embodiment. The method 80 is performed by an electronic control unit (e.g., ECU 600, FIG. 6) included in the motorcycle. As shown in FIG. 6, the ECU 600 may include an electronic processor 602, e.g., a microprocessor, an application specific integrated circuit, or the like. In some embodiments, the ECU 600 also includes a non-transitory computer readable memory 604 for storing limits or other predetermined parameters, e.g., for regenerative braking, mappings or tables, or the like. The ECU 600 also includes an input/output interface 606 for communicating with other components included in the vehicle 20 via one or more wired or wireless communication channels or networks. For example, the ECU 600 may be configured to receive data from the twist grip sensor 84, the control sensor 90, one or more sensors 607 monitoring operating parameters of the electric motor 58 (e.g., detecting RPM), or the like, and may be configured to transmit data, including a torque command, to a motor controller 608 for the electric motor 58. Note that the functions described herein as being performed by ECU 600 may be distributed among multiple electronic control units. For example, in some embodiments, other components included in vehicle 20, such as other ECUs, sensors, etc., may perform at least a portion of method 80.

As shown in FIG. 5, the method 80 includes detecting (at block 82) the position of the twist grip 74. As described above, the twist grip sensor 84 may be configured to detect the position of the twist grip 74 (among multiple positions) using a rotary encoder, Hall effect sensor, or the like, and output a current position of the twist grip 74, which may represent a value between 0% and 100% of the maximum drive torque available. In some embodiments, redundant sensor assemblies (e.g., sensor assemblies) may be used to ensure proper operation of the twist grip 74 and the twist grip sensor 84. The twist grip sensor 84 may be configured to not only determine the position (604A) of the twist grip 74, but also to detect faults or other errors. Also, in some embodiments, the twist grip sensor 84 may apply various checks for faults or other errors. As described above, the ECU 600 may be in communication with the twist grip sensor 84. Thus, in some embodiments, the ECU 600 detects the current position of the twist grip 74 based on data received from the twist grip sensor 84.

The method 80 also includes mapping (at block 86) the detected position of the twist grip 74 to a requested drive torque. As described above, the position of the twist grip 74 may be mapped to a requested drive torque using a two-dimensional table that maps the position of the twist grip and the speed of the motorcycle (RPM of the electric motor 58) to a requested drive torque. In some embodiments, if the vehicle 20 includes multiple ride modes, a requested drive torque may be calculated for each ride mode, and the ECU 600 may select the calculated requested drive torque for the currently active ride mode. In other embodiments, the ECU 600 may calculate the requested drive torque only for the currently active ride mode.

The method 80 also includes detecting (at block 88) the position of the controller 72. As described above, the control sensor 90 may be configured to detect the position of the controller 72 (among multiple positions) and output a current position of the controller 72, which may represent a value between 0% and 100% of a predetermined maximum braking torque available. In some embodiments, the control sensor 90 may apply various checks for faults or other errors. As described above, the ECU 600 may be in communication with the control sensor 90 such that the ECU 600 may detect the current position of the controller 72 based on data received from the control sensor 90.

Method 80 also includes mapping (at block 92) the position of controller 72 to a requested braking torque. As discussed above, the position of controller 72 may be mapped to a requested braking torque using a one-dimensional table or equation. For example, FIG. 7 illustrates generally one equation that may be applied by ECU 600 to perform the mapping. As shown in FIG. 7, ECU 600 divides the current position of controller 72 by the maximum position (stored in memory or software) and multiplies the result by the maximum braking torque (N/m). The result of the multiplication represents the requested braking torque (N/m). As discussed above, ECU 600 may also perform various checks for faults or other errors.

Returning to FIG. 5, the ECU 600 determines a torque command at block 94 based on the desired drive torque and the desired braking torque. The resulting torque command is then sent (at block 96) to the motor controller 608 for the electric motor 58. In some embodiments, determining the torque command includes summing the desired drive torque (defined by the position of the twist grip 74) and the desired braking torque (defined by the position of the control device 72).

In some embodiments, when regenerative braking is used as the only mechanism for braking the motorcycle wheels, additional braking functions such as anti-lock braking systems and traction control can also be implemented on the vehicle 20 using regenerative braking, avoiding the need for heavy and expensive systems to provide those additional functions and systems (e.g., hydraulic ABS units). In addition, through configuration of both the mechanical operation of the controller 72 and the mapping of the position of the controller 72 to the requested braking torque, regenerative braking can replicate the function and feel of a traditional mechanical friction brake, such as a hydraulic rear brake (through a process described herein also referred to as providing a virtual brake). This eliminates the cost, weight and duplication of a mechanical braking system without sacrificing performance or driver experience. For example, although the controller 72 is an electronic control or lever, the biasing force applied via the controller 72 can be configured to provide feedback to the driver as if the driver were actuating a traditional brake lever. Specifically, the controller 72 can provide similar feedback to the driver because a traditional brake lever (or pedal) provides more resistance the more the lever (or pedal) is actuated. Additionally, the maximum amount of torque applied via regenerative braking can be similarly configured (via a mapping of controller 72 position to braking torque) to be less than the maximum drive torque that can be requested via actuation of twist grip 74, such that the driver can apply conventional friction brakes (hydraulic brakes) and then actuate twist grip 74 to effectively "drive through" the applied brakes.

In some embodiments, the biasing force applied via the controller 72 (in lieu of or in addition to the "virtual braking" described above) may be configured to provide feedback to the driver as if the driver were activating a conventional clutch of the vehicle 20 (referred to herein as providing a virtual clutch). Specifically, when a biasing force is applied to the controller 72, a torque request (for either a positive or negative amount of torque) may be generated and applied to the motorcycle's electric motor 58. The amount of torque included in the request corresponds to the position of the controller 72. For example, when the controller 72 is fully actuated (e.g., fully retracted in the case of a pivot lever), the corresponding torque request is 0%, and when the controller 72 is not actuated (e.g., not retracted in the case of a pivot lever), the corresponding torque request is 100%. The amount of torque applied may be any percentage between 0% and 100% based on the particular position of the controller 72 (the amount the controller 72 is actuated). When implementing the virtual clutch, the ECU 600 may be configured to multiply the requested drive torque and the requested torque (as a percentage corresponding to the position of the controller 72) when determining the torque command in block 94 of the method 80, and determine the amount of torque in the torque command based on the result. That is, application of the controller 72 reduces the requested torque command (whether it is a positive or negative torque) to approach zero, and when the lever is fully pulled in, zero torque is requested regardless of the regenerative setting or the position of the twist grip 74.

The ECU 600 may be configured to provide either or both of a virtual brake and a virtual clutch. In some embodiments, where only a virtual clutch is provided, the vehicle 20 may include only a purely mechanical braking system. In embodiments where both a virtual brake and a virtual clutch are provided, the driver of the vehicle 20 may select to engage either the virtual brake or the virtual clutch via a separate or common input mechanism (e.g., a dial, switch, etc.). For example, FIG. 8 is a schematic diagram 800 showing a process flow 802A for a virtual brake and a process flow 802B for a virtual clutch. A user of the vehicle 20 may select which process to use via an input mechanism 804 (illustrated as a switch). As shown in the process flow 802A for a virtual brake, the drive torque request (requested drive torque 806A) determined in block 86 of the method 80 of FIG. 5 is added to the requested torque (braking torque request 808A). In the process of determining the requested torque 808A, in the case of virtual braking, the ECU 600 may determine the requested torque 808A by dividing the position of the control device 72 by the maximum position of the twist grip 74, and the result may be multiplied by the maximum (braking) torque (FIG. 7).

Returning to FIG. 8, the virtual clutch process flow 802B may include multiplying the requested drive torque (Requested Drive Torque 806B) by the position of the controller 72 (Position 808B), where the amount of torque applied according to the torque command 810 is determined independently of the position of the twist grip 74.

In some implementations, the rear wheels 24 are braked using only regenerative braking, as described above. However, in other embodiments, the rear wheels 24 also include mechanical brakes. The driver may activate the mechanical brakes by activating a separate actuator on the vehicle 20. For example, in some embodiments, the driver may be able to selectively turn regenerative braking on and off through the selection of one or more ride modes. For example, one or more of the ride modes available to the driver may provide regenerative braking, while other ride modes may provide only mechanical friction braking. Also, in some embodiments, the driver may use the same actuator to apply regenerative braking or mechanical braking. The type of braking applied may be based on the currently selected ride mode, current operating parameters of the vehicle 20, current environmental conditions, etc. For example, in some embodiments, a control system included in the vehicle 20 may automatically determine whether to apply regenerative braking, mechanical braking, or a combination thereof. Thus, in some embodiments, through actuation of a single brake control device, the driver may specify the amount of braking required, and a control system included in the vehicle 20 may automatically determine the type of braking (including, in some circumstances, a combination of different types of braking) to apply to meet the request.

Also, the braking described above for the rear wheels 24 may be applied to the front wheels 22 as well. Thus, in some embodiments, the vehicle 20 does not include any mechanical friction brakes, but rather uses regenerative braking as the only mechanism for slowing and stopping the vehicle 20.

In addition, the vehicle 20 described herein is presented as an example of a motorcycle including the disclosed regenerative braking and associated controls. However, the regenerative braking described herein can be used with other motorcycles 20 (and other types of vehicles). For example, in some embodiments, the vehicle 20 is powered by an internal combustion engine (ICE) instead of or in addition to an electric powertrain. In this embodiment, the vehicle 20 including the ICE may use regenerative braking as the only mechanism for braking both wheels of the vehicle 20, as described above. Alternatively, the vehicle 20 including the ICE may use regenerative braking as the only mechanism for braking one wheel, such as the rear wheel 24, but may include a mechanical brake, such as a friction disc brake, to brake the other wheel.

Various features and advantages of the present invention are set forth in the following claims.

20 Vehicle 22 Front wheel 24 Rear wheel 28 Main frame 32 Front fork 36 Head tube 40 Handlebar 44 Swing arm 46 Shock absorber unit 48 Seat 54 Power storage unit 58 Electric motor 62 Endless drive member 66 Driving sprocket 68 Driven sprocket 72 Control device 74 Twist grip 84 Twist grip sensor 90 Control sensor 600 ECU

Claims (4)

1. A method of operating an electric motor in a vehicle, the method comprising:
detecting a position of a first control device included in the vehicle, the first control device controlling a drive torque of the vehicle;
detecting a position of a second control device included in the vehicle, the second control device being for controlling braking force of wheels of the vehicle;
correlating a sensed position of the first controller to a first demanded torque;
relating a position of the second controller to a second demanded torque, the second demanded torque being expressed as a percentage between 0 and 100% based on the position of the second controller;
determining a torque command based on the first requested torque and the second requested torque using an electronic control unit by multiplying the first requested torque by the second requested torque;
transmitting the torque command to an electric motor included in the vehicle;
A method comprising: A system for operating an electric motor of a two-wheeled vehicle, the system including at least one electronic control unit included in the vehicle,
The at least one electronic control unit is
Detecting a position of a first control device included in the vehicle and configured to control a drive torque of the vehicle;
Detecting a position of a second control device included in the vehicle;
correlating a sensed position of the first controller to a first demanded torque;
relating a position of the second controller to a second demanded torque;
determining a torque command based on the first requested torque and the second requested torque;
applying a torque limit to the summed torque values;
transmitting the torque command to an electric motor included in the vehicle;
A system configured to: The system of claim 2, wherein the electronic control unit determines the torque command by summing the first requested torque and the second requested torque. The system of claim 2 , wherein the electronic control unit determines the torque command based on a product of the first demanded torque and the second demanded torque.

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