DESC:PREAMBLE
The complete application claims the benefit of provisional application number 202341072723 filed on 25 October, 2023. The complete application fully and particularly describes the invention and the method in which it is to be performed.

TECHNICAL FIELD
[0001] The present disclosure relates to a Braking System (BS) in a vehicle. In particular, the present disclosure allows a driver to control speed of the vehicle solely through throttle so that deceleration of the vehicle is consistent across all States of Charges (SoCs) of battery and at all speeds of the vehicle.

BACKGROUND
[0002] Regenerative braking is an inherent function in Electric Vehicles (EVs) that recovers energy typically dissipated as heat during braking. This recuperated energy is then converted back into electrical power and stored in the vehicle’s battery. Nonetheless, the regenerative braking function encounters a range of constraints and issues in both two-wheeler and four-wheeler EVs.
[0003] Typically, a driver of the EV has to select an option from various levels of regenerative braking (such as low, medium, high, etc.) for controlling the vehicle and often lacks a direct control over a precise amount of deceleration torque to be applied to wheels. The deceleration torque is determined by Rotations Per Minute (RPM) of the vehicle, which is often a fixed value derived from a lookup table containing torque-RPM curves.
[0004] Further, the deceleration torque fetched from the lookup table provides an inconsistent deceleration feel for the rider/driver across an entire RPM range. FIG. 1 illustrates a curved graph (100) representing torque (power) of the vehicle with respect to the motor’s RPM, as is known in the art. As illustrated, the torque at high speeds is significantly lower than at low speeds, and as a result, the riders/drivers experience varying levels of deceleration across the entire RPM range.
[0005] Furthermore, the regenerative braking is constrained by a capacity of vehicle’s battery to handle a charging current, thus making it difficult to apply equally high levels of regenerative current at both high and low States of Charge (SoC) of the battery. This affects regeneration consistency across the entire state of charge range.
[0006] There is, therefore, a need for an improved mechanism to allow the driver to manage speed of the EV solely through throttle so that a consistent deceleration experience is achieved across all the SoCs and at all speeds.

OBJECTS OF THE PRESENT DISCLOSURE
[0007] A general object of the present disclosure is to provide a braking system for controlling speed of a vehicle through throttle so that deceleration of the vehicle is consistent across all States of Charges (SoCs) of battery and at all speeds of the vehicle.
[0008] An object of the present disclosure is to provide the throttle which can move on both positive side and negative side of a neutral point, where movement on the positive side signifies positive acceleration, and the movement on the negative side signifies negative or deceleration torque.
[0009] Another object of the present disclosure is to tune the torque - Rotations Per Minute (RPM) maps by taking into account rolling resistance and air drag features thus resulting in a consistent deceleration number across the whole RPM range.
[0010] Another object of the present disclosure is to arbitrate between dissipated power and regenerated power, such that the regenerated power from the vehicle is used to charge the battery and the rest is dissipated, thereby allowing availability of a significant amount of power across a whole SoC band to be used during dissipation for consistent deceleration of the vehicle.
[0011] Another object of the present disclosure is to select a torque value from a lookup table based on a determined vehicle state and a motor RPM. Entries of the lookup table are based on a determined decelerating effect of a motor, air drag, and rolling resistance on the vehicle, for consistent deceleration irrespective of the speed of the vehicle.

SUMMARY
[0012] Aspects of the present disclosure relate to a Braking System (BS) in a vehicle. In particular, the present disclosure allows a driver to control speed of the vehicle solely through throttle so that deceleration of the vehicle is consistent across all States of Charges (SoCs) of battery and at all speeds of the vehicle.
[0013] In an aspect, a method for consistently controlling speed of a vehicle through a throttle includes receiving a present state and a maximum allowable charging limit of a battery during regeneration. The method includes determining a vehicle state, and transmitting the determined vehicle state and an updated allowable charging limit of the battery to a motor controller. Further, the method includes obtaining information corresponding to a motor Revolutions Per Minute (RPM), a motor temperature, and a motor controller temperature from the motor controller to determine an amended state of the vehicle and one or more fault states. In addition, the method includes sending the amended state of the vehicle and the one or more fault states to the battery and the motor controller.
[0014] In some embodiments, the method may receive the present state and the maximum allowable charging limit of the battery, based on information corresponding to cell voltage, SoC, States of Health (SoH), a battery temperature, the motor temperature, and the motor controller temperature.
[0015] In some embodiments, deceleration power may be routed to dissipation when the SoC of the battery is high, and wherein the deceleration power is routed to regeneration when the SoC of the battery is low.
[0016] In some embodiments, upon the deceleration power being routed to the dissipation when the SoC of the battery is high, a consistent vehicle deceleration may be achieved.
[0017] In some embodiments, the vehicle state may be determined based on one or more Human-Machine Interface (HMI) inputs and observed changes in one or more vehicle parameters. Further, the updated allowable charging limit of the battery may be determined based on a buffer capacity appended to the received maximum allowable charging limit from the battery.
[0018] In some embodiments, an angular displacement of the throttle may be performed by the vehicle controller, based on the one or more HMI inputs. A positive input may generate an acceleration torque and a negative input may generate a deceleration torque.
[0019] In some embodiments, the buffer capacity may be appended by the vehicle controller to the received maximum allowable charging limit from the battery to accommodate estimation and calibration errors.
[0020] In some embodiments, the motor controller may select a torque value from a lookup table based on the determined vehicle state and the motor RPM.
[0021] In some embodiments, the method includes tuning, by the vehicle controller, a vehicle torque based on predetermined values provided in the lookup table. The lookup table may include a unique torque value with respect to each motor RPM value of the vehicle.
[0022] In some embodiments, one or more entries of the lookup table may be dynamically adjusted, based on a determined decelerating effect of a motor, air drag, and rolling resistance on the vehicle, for consistently controlling the speed of the vehicle.
[0023] In some embodiments, the method includes determining, by the vehicle controller, a reference value to control the motor controller to obtain and control at least one of a combination of the unique torque value and a generated regenerative power simultaneously.
[0024] In some embodiments, the method includes arbitrating, by the vehicle controller, between dissipated power and the generated regenerative power. Further, an allowable limit of the generated regenerative power may be used to charge the battery.
[0025] In an aspect, a system for consistently controlling speed of a vehicle through a throttle is provided. The system includes one or more vehicle controllers and a memory coupled to the one or more vehicle controllers. The memory comprises one or more vehicle controller-executable instructions which, when executed, cause the one or more vehicle controllers to receive a present state and a maximum allowable charging limit of a battery during regeneration and determine a vehicle state. The vehicle controllers may transmit the determined vehicle state and an updated allowable charging limit of the battery to a motor controller, obtain information corresponding to a motor RPM, a motor temperature, and a motor controller temperature from the motor controller to determine an amended state of the vehicle and one or more fault states and send the amended state of the vehicle and the one or more fault states to the battery and the motor controller.
[0026] In some embodiments, deceleration power may be routed to dissipation when a SoC of the battery is high. Further, the deceleration power may be routed to regeneration when the SoC of the battery is low.
[0027] In some embodiments, a consistent vehicle deceleration may be achieved upon the deceleration power being routed to the dissipation.
[0028] In some embodiments, the vehicle state may be determined based on one or more HMI inputs and observed changes in one or more vehicle parameters. The updated allowable charging limit of the battery may be determined based on a buffer capacity appended to the received maximum allowable charging limit from the battery.
[0029] In some embodiments, the buffer capacity may be appended to the received maximum allowable charging limit from the battery to accommodate estimation and calibration errors.
[0030] In some embodiments, the motor controller may select a torque value from a lookup table based on the determined vehicle state and the motor RPM.
[0031] In some embodiments, the vehicle controller may tune a vehicle torque based on predetermined values provided in the lookup table. The lookup table may include a unique torque value with respect to each motor RPM value of the vehicle.
[0032] In some embodiments, the vehicle controller may dynamically adjust one or more entries of the lookup table based on a determined decelerating effect of a motor, air drag, and rolling resistance on the vehicle, for consistently controlling the speed of the vehicle.
[0033] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[0035] FIG. 1 illustrates a curved graph representing torque (power) of a vehicle with respect to motor’s RPM, as is known in the art.
[0036] FIG. 2 illustrates a schematic block diagram of an exemplary (electronic only) braking system of the vehicle, according to embodiments of the present disclosure.
[0037] FIG. 3 illustrates an exemplary block diagram of a vehicle controller of the braking system, according to embodiments of the present disclosure.
[0038] FIG. 4 is an exemplary block diagram illustrating a vehicle control unit of the braking system to perform arbitration between regenerated power and dissipated power in the vehicle, according to embodiments of the present disclosure.
[0039] FIG. 5 illustrates a side view of a throttle for showing a throttle’s angular displacement, according to embodiments of the present disclosure.
[0040] FIG. 6 illustrates a graph showing a decelerated and an accelerated torque of the vehicle with respect to a negative angular displacement and a positive angular displacement of the throttle respectively, in accordance with an embodiment of the disclosure.
[0041] FIG. 7 illustrates a graph showing deceleration with respect to adjusted speed of the vehicle.
[0042] FIG. 8 illustrates a graph showing the regenerative power of the battery that changes with States of Charges (SOC), in accordance with the embodiment of the disclosure.
[0043] FIG. 9A illustrates an exemplary scenario showing regenerative current being fed into the battery for controlling the torque of the vehicle , in accordance with the embodiment of the disclosure.
[0044] FIG. 9B illustrates an exemplary scenario showing controlled regenerative current and dissipated regenerative current being fed into the battery for controlling the torque of the vehicle, in accordance with the embodiment of the disclosure.
[0045] FIG. 9C illustrates an exemplary scenario showing entire regenerative content being converted to dissipative current and fed to the battery for controlling the torque of the vehicle, in accordance with the embodiment of the disclosure.
[0046] FIG. 10 illustrates a graph showing an amount of deceleration power that is achieved through regeneration (shown as hashed lines), and net deceleration power if dissipation along with the regeneration is taken into account (shown as horizontal lines), in accordance with an embodiment of the disclosure.
[0047] FIG. 11 illustrates a graph showing an amount of deceleration power achieved from the regeneration (shown as hashed lines), and net deceleration power available (shown as horizontal lines), in accordance with an embodiment of the disclosure.
[0048] FIG. 12 illustrates an exemplary method for consistently controlling speed of a vehicle through a throttle, in accordance with an embodiment of the disclosure.
[0049] FIG. 13 illustrates an exemplary computer system in which or with which the proposed system may be implemented, according to embodiments of the present disclosure.

DETAILED DESCRIPTION
[0050] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such details as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the present disclosures as defined by the appended claims.
[0051] Throughout the specification, “actuate,” “actuating,” “actuated” or any variation thereof mean and include bringing a component to an actuated state to cause said component to operate.
[0052] Throughout the specification, “engage,” “engaging,” “engaged” or any variations thereof mean and include using, operating, involving, or employing a component to perform the intended operation thereof.
[0053] Embodiments explained herein relate to a Braking System (BS) in a vehicle. In particular, the present disclosure allows a driver to control speed of the vehicle solely through throttle so that deceleration of the vehicle is consistent across all States of Charges (SoCs) of battery and at all speeds of the vehicle.
[0054] In an aspect, the braking system for consistently controlling speed of the vehicle through the throttle includes one or more vehicle controllers and a memory coupled to the one or more vehicle controllers. The memory includes one or more vehicle controller-executable instructions which, when executed, cause the one or more vehicle controllers to receive a present state and a maximum allowable charging limit of the battery during regeneration. The vehicle controller determines a vehicle state and transmits the determined vehicle state and an updated allowable charging limit of the battery to a motor controller. Further, the vehicle controller obtains information corresponding to a motor Revolutions Per Minute (RPM), a motor temperature, and a motor controller temperature from the motor controller to determine an amended state of the vehicle and one or more fault states. The vehicle controller may further send the amended state of the vehicle and the one or more fault states to the battery and the motor controller.
[0055] Various embodiments of the present disclosure will be explained in detail with respect to FIGs. 2-12.
[0056] FIG. 2 illustrates a schematic block diagram (200) of an exemplary braking system (201), according to embodiments of the present disclosure. As shown, the system (201) may be implemented in a vehicle (202) having two or more wheels. In some embodiments, the vehicle (202) may be indicative of any locomotive that uses wheels for movement. The vehicle (202) may be decelerated or stopped using a throttle (210). In some embodiments, the vehicle (202) may include, but not limited to, electric bikes, motor bikes, scooters, mopeds, auto-rickshaws, three-wheeled vehicles, cars, vans, trucks, and the like. While the present disclosure describes the system (201) in the context of two-wheeled and four-wheeled vehicles, it may be appreciated by those skilled in the art that the system (201) may be suitably adapted for vehicles having any number of wheels.
[0057] In an embodiment, the disclosed system (201) may provide a means to facilitate modulation of speed of an Electric Vehicle (EV) in city traffic. The disclosed system (201) may allow the driver to control speed of the vehicle (202) using the throttle (210) such that deceleration of the vehicle is consistent across all the SoCs of a battery (206) and at all speeds. The disclosed system (201) may use regeneration and power dissipation mechanisms in vehicular components such as, but not limited to, a motor (212), a bleed resistor, and the like to achieve required negative torque at the wheels.
[0058] In some embodiments, the vehicle (202) may have one or more vehicle controllers (204) (also referred to herein as a vehicle controller (204)) for performing a bi-directional communication with the motor controller (208) and the battery (206). The vehicle may have the motor (212) connected to and controlled by the motor controller (208). The vehicle controller (204) may receive a present state and a maximum allowable charging limit of the battery (206) during regeneration, based on information corresponding to cell voltage, the SoC, States of Health (SoH), a battery temperature, a motor temperature, and a motor controller temperature.
[0059] The motor controller (208) may receive throttle input signals from the throttle (210) of the vehicle (202) and may transmit the received throttle input signals to the motor (212). Power generated at the motor (212) may be dissipated within the motor (212). Further, the motor (212) may transmit regenerative current to the battery (206). In addition, the motor (212) may transmit negative torque to rear wheel (214) of the vehicle (202). Also, encoder and temperature signals may be exchanged between the motor controller (208) and the motor (212). The battery (206) may supply power to the motor controller (208) through power lines.
[0060] In some embodiments, the vehicle controller (204) may determine a vehicle state based on one or more Human-Machine Interface (HMI) inputs along with changes observed in one or more vehicle parameters. In addition, an updated allowable charging limit of the battery (206) may be determined based on a buffer capacity appended to the received maximum allowable charging limit from the battery (206). Further, the buffer capacity may be appended to the received maximum allowable charging limit from the battery (206) to accommodate estimation and calibration errors.
[0061] In some embodiments, the vehicle controller (204) may transmit the determined vehicle state and an updated allowable charging limit of the battery to the motor controller (208).
[0062] In some embodiments, the vehicle controller (204) may obtain information corresponding to the motor RPM, the motor temperature, and the motor controller temperature from the motor controller (208) to determine an amended state of the vehicle (202) and one or more fault states. In an embodiment, the vehicle controller (204) may perform an angular displacement of the throttle (210) based on the one or more HMI inputs. It is to be noted that a positive HMI input may generate an acceleration torque and a negative HMI input may generate a deceleration torque. The motor controller (208) may select a torque value from a lookup table based on the determined vehicle state and the motor RPM. Further, the vehicle controller (204) may tune a vehicle torque based on predetermined values provided in the lookup table. The lookup table may include a unique torque value with respect to each motor RPM value of the vehicle (202). In an embodiment, for consistently controlling the speed of the vehicle (202), one or more entries of the lookup table may be dynamically adjusted based on a determined decelerating effect of the motor (212), air drag, and rolling resistance on the vehicle (202).
[0063] In some embodiments, the vehicle controller (204) may determine a reference value that may be used to control the motor controller (208) to obtain and control at least one of a combination of the unique torque value and a generated regenerative power simultaneously.
[0064] In some embodiments, the vehicle controller (204) may arbitrate between dissipated power and the generated regenerative power. In addition, an allowable limit of the generated regenerative power may be used to charge the battery (206).
[0065] In some embodiments, the vehicle controller (204) may send the amended state of the vehicle (202) and the one or more fault states to the battery (206) and the motor controller (208).
[0066] In some embodiments, a deceleration power may be routed to dissipation when the SoC of the battery (206) is high and the deceleration power may be routed to regeneration when the SoC of the battery (206) is low. In an embodiment, upon the deceleration power being routed to the dissipation when the SoC of the battery (206) is high, a consistent vehicle deceleration may be achieved.
[0067] FIG. 3 illustrates an exemplary block diagram (300) of the vehicle controller (204) of the braking system (201), according to embodiments of the present disclosure.
[0068] As shown, the vehicle controller (204) may include one or more processor(s) (302). The one or more processor(s) (302) may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, logic circuitries, and/or any devices that manipulate data based on operational instructions. Among other capabilities, the one or more processor(s) (302) may be configured to fetch and execute computer-readable instructions stored in a memory (304) of the vehicle controller (204). The memory (304) may store one or more computer-readable instructions or routines, which may be fetched and executed to create or share the data units over a network service. The memory (304) may include any non-transitory storage device including, for example, volatile memory such as Random Access Memory (RAM), or non-volatile memory such as Erasable Programmable Read-Only Memory (EPROM), flash memory, and the like.
[0069] In some embodiments, the vehicle controller (204) may also include an interface(s) (306). The interface(s) (306) may include a variety of interfaces, for example, interfaces for data input and output devices, referred to as Input-Output (I/O) devices, storage devices, and the like. The interface(s) (306) may facilitate communication between one or more components of the system (201). The vehicle controller (204) may be coupled to a database (322) that stores one or more data units therein. The database (322) may include data that is either stored or generated as a result of functionalities implemented by any of the components of processing module(s) (308). In some embodiments, the one or more data units may be indicative of the predetermined threshold values.
[0070] In some embodiments, the vehicle controller (204) may include one or more processing module(s) (308). In some embodiments, the processing module(s) (308) may be implemented as a combination of hardware and programming (for example, programmable instructions) to implement one or more functionalities of the processing module(s) (308). In examples described herein, such combinations of hardware and programming may be implemented as processor-executable instructions stored on a non-transitory machine-readable storage medium and the hardware for the processing module(s) (308) may include a processing resource (for example, one or more processors), an Application-Specific Integrated Circuit (ASIC), an electronic circuit, or the like, that execute such instructions.
[0071] In an embodiment, the processing module(s) (308) may include a receiving module (310), a determination module (312), a transmitting module (314), an acquisition module (316), and other module(s) (318). The other module(s) (318) may implement functionalities that supplement applications or functions performed by the vehicle controller (204).
[0072] In some embodiments, the receiving module (310) may receive a present state and a maximum allowable charging limit of the battery (206) during regeneration. The receiving of the present state and the maximum allowable charging limit of the battery (206) may be based on information related to the cell voltage, the SoC, the SoH, the battery temperature, the motor temperature, and the motor controller temperature of the vehicle (202).
[0073] In some embodiments, the determination module (312), may determine the vehicle state, based on the one or more HMI inputs and the observed changes in the one or more vehicle parameters. Further, the updated allowable charging limit of the battery (206) may be determined based on the buffer capacity appended to the received maximum allowable charging limit from the battery (206).
[0074] In some embodiments, the transmitting module (314) may transmit the determined vehicle state and the updated allowable charging limit of the battery (206) to the motor controller (208).
[0075] In some embodiments, the acquisition module (316) may obtain information corresponding to the motor RPM, the motor temperature, and the motor controller temperature from the motor controller (208) to determine the amended state of the vehicle (202) and one or more fault states. Further, the motor controller (208) may select the torque value from the lookup table based on the determined vehicle state and the motor RPM. In addition, the vehicle torque may be tuned based on predetermined values provided in the lookup table.
[0076] In some embodiments, the transmitting module (314) may send the amended state of the vehicle (202) and the one or more fault states to the battery (206) and the motor controller (208).
[0077] FIG. 4 is an exemplary block diagram (400) illustrating a vehicle control unit of the braking system (201) to perform arbitration between regenerated power and dissipated power in the vehicle (202), according to embodiments of the present disclosure.
[0078] In an embodiment, the braking system (201) may gather information of different working states of the vehicle in order to accomplish an arbitration between a dissipated power state and a regenerated power state. A vehicle control unit (402) of the vehicle may capture information about various attributes of the battery (206) such as the cell voltage, the SoC, the SoH, and the cell temperature, so as to determine what is a maximum allowable charging current that is available during the power regeneration. It may be appreciated that the vehicle control unit (402) may be similar to the vehicle controller (204) of FIG. 2 in its functionality.
[0079] The battery (206) may communicate information related to a permissible limit of the charging current of the battery, and various states of the battery (206) to the vehicle control unit (402) via communication lines. Based on the received information, the vehicle control unit (402) may further incorporate a buffer space to accommodate estimated and calibration errors. In addition, the vehicle control unit (402) may determine any unexpected changes that may occur in the parameters associated with the vehicle, and input from the driver facing the HMI to decide the current state of the vehicle (202), according to which other subsystems of the vehicle (202) may respond.
[0080] The vehicle control unit (402) may send information related to both the state of the vehicle and new charging current limits to the motor controller (208). The motor controller (208) may evaluate values of the current limits of the vehicle along with the state of the vehicle received from the vehicle control unit (402). The motor controller (208) may choose a particular torque and a throttle map based on the state of the vehicle to maintain a balance and stay within Direct Current (DC) boundaries communicated by the vehicle control unit (402).
[0081] The motor controller (208) may communicate information related to parameters such as the RPM of the motor, the motor temperature, and the controller temperature to the vehicle control unit (402) to execute additional required actions.
[0082] Based on the information received from the motor controller (208), the vehicle control unit (402) may determine a state of the vehicle and its various associated fault states. This information may be further communicated to the battery (206) of the vehicle (202).
[0083] FIG. 5 illustrates a side view (500) of the throttle (210) for showing throttle’s angular displacement, according to embodiments of the present disclosure.
[0084] In an embodiment, to control speed of the vehicle (202), the vehicle (202) may receive various instructions from a driver related to controlling an amount of vehicle deceleration. Further, a high level of precision may be applied to control reference torques with respect to the received instructions from the driver. To control the reference torques, the braking system (201) may implement the throttle (210) which has a flexibility of movement for implementing a positive torque and a negative torque. An input on the positive side of a neutral point, from the driver, may signify the positive or acceleration torque, and the input on the negative side may signify the negative or deceleration torque.
[0085] As depicted in FIG. 5, the angular displacement of the throttle is on the negative side with respect to a neutral point. This displacement of the throttle on the negative side may equate to generating a desired deceleration torque by the driver. As may be appreciated, the movement of the throttle on both the positive side and the negative side of the torque may facilitate a predictable and consistent driving experience to the driver.
[0086] FIG. 6 illustrates a graph (600) showing a decelerated torque and an accelerated torque of the vehicle (202) with respect to a negative angular displacement and a positive angular displacement of the throttle respectively, in accordance with an embodiment of the disclosure. As illustrated, the throttle’s angular displacement in the negative side is linearly mapped to the requested deceleration torque shown in the adjoining plot thus giving a higher predictability and consistent experience to the rider.
[0087] In an embodiment, the braking system (201) may facilitate to provide consistency in deceleration across the different RPMs. Typically, an experience of controlling the vehicle speed through the throttle alone is degraded if the amount of deceleration of the vehicle is not consistent across the entire RPM range. This implies that if the deceleration torque is not consistent across the entire RPM range, it may lead to the rider feeling unexpectedly higher torque in some regions and unexpectedly lower torque in others. This may reduce the predictability of the vehicle on the driver’s input.
[0088] Therefore, to achieve a consistent amount of deceleration for the vehicle (202), the torque - RPM maps may be tuned, while taking into account external factors such as rolling resistance and air drag to achieve a near consistent deceleration number across the whole RPM range. The contributing factors to the vehicle’s deceleration may be, for example, the air drag, the rolling resistance and a negative torque applied by the motor (212). The air drag on the vehicle (202) may be modelled using the following equation :
…. eq (1)
[0089] The rolling resistance on the vehicle nay be modelled as :
…. eq (2)
[0090] Deceleration contributed by the motor may be represented as:
…. eq (3)
where,
is the density of air
is the frontal area of the vehicle
is the drag coefficient of the vehicle
is the velocity of the vehicle
is the rolling resistance coefficient
is the mass of the vehicle
is the acceleration due to gravity
is the max torque output of the motor for the given RPM
is the final drive ratio of the vehicle, and
is the radius of the rear wheel of the vehicle
Thus, the net force on the vehicle (202) is determined as :
…. eq (4)
…. eq (5)
[0091] The only parameter that may be controlled in the equation (5) is torque output of the motor (212), denoted as ‘t’. Therefore, to achieve a consistent amount of deceleration for the vehicle (202), torque - RPM maps may be tuned. The torque - RPM maps may be tuned such that net force denoted as ‘F’ is consistent across the speed of the vehicle, denoted as ‘v’.
[0092] FIG. 7 illustrates a graph (700) showing the deceleration achieved from the motor (212) which is denoted as and net deceleration achieved which is denoted as including all the contributing factors. As is illustrated, the torque - RPM maps (shown as dotted line) represents net warp force and may take into account external factors such as the rolling resistance and the air drag that have achieved a near constant deceleration number across a whole RPM range. The torque - RPM maps (shown as solid line) represents warp force and may take into account the deceleration achieved from the motor. The system (201) facilitates to achieve a minimum net deceleration force across the RPM range that is not less than 20% of maximum deceleration across the entire RPM range.
[0093] In some embodiments, the system (201) facilitates implementation of a consistent SoC band. Typically, the current with which the EV’s battery may be charged is limited by its SoC i.e. at the higher SoCs, the battery may not be charged with the same current with which the battery can be charged at the lower SoCs. In case, the deceleration torque is achieved using only the regenerative current, then at high SoCs, a little to no deceleration torque may be provided. Thus, having different deceleration torques at different SoCs may deliver inconsistent ride experiences to the driver.
[0094] FIG. 8 illustrates a graph (800) showing regenerative power of the battery (206) that changes with the SoC, in accordance with the embodiment of the disclosure. As illustrated, the battery (206) may allow higher availability of the current at intermediate SoCs. However, the available regenerative power may taper off drastically at both extremes of the SoC.
[0095] Due to this limitation posed by the battery (206), it may be impossible to achieve a consistent deceleration across a whole SoC band using the regeneration alone.
[0096] In an embodiment, when the power contributed by dissipation is also used, the net available power across the whole SoC band may increase by a constant. This happens because the power dissipation is independent of the state of charge of the battery.
[0097] In an embodiment, the system (201) may control the amount of current being fed back independently into the battery (206) denoted as IDC and the torque output of the motor (212) denoted as t, within constraints of a physical system. Therefore,
…. eq (6)
….eq (7)
…. eq (8)
…. eq (9)

On substituting equation (7) and equation (8) in equation (9), results in

... eq (10)
.... eq (11)
Equations (10) and (11) may be represented in the following form :
Idc = F (id, iq)
t = G (id, iq)
These may be represented as
id = S1(Idc, t) …. eq (12)
iq= S2(Idc, t) …. eq (13)

Equations (12) and (13) show that there are unique values of motor currents id and iq for any combination of the torque and the regenerative current (Idc). This implies that if the id and the iq are controlled adequately then drive experience (Torque) and regen current Idc may be controlled simultaneously.
[0098] FIG. 9A illustrates an exemplary scenario (910) showing regenerative current being fed into the battery for controlling the torque of the vehicle (202), in accordance with the embodiment of the disclosure. In an embodiment, the exemplary scenario (910) depicts a regeneration scenario where all power generated from the motor (212) is fed back to the battery (206). Th exemplary scenario (910) shows one of the statuses of Field Effect Transistors (FETs) which allows regeneration.
[0099] FIG. 9B illustrates an exemplary scenario (920) showing controlled regenerative current and dissipated regenerative current being fed into the battery for controlling the torque of the vehicle (202), in accordance with the embodiment of the disclosure. In an embodiment, in the exemplary scenario (920), a part of the power from the motor (212) is fed back to the battery (206), and the other part of the power is dissipated by circulating it within the motor (212) and the controller (208) itself.
[00100] FIG. 9C illustrates an exemplary scenario (930) showing entire regenerative content being converted to dissipative current and fed to the battery for controlling the torque of the vehicle (202), in accordance with the embodiment of the disclosure. In an embodiment, in the exemplary scenario (930), all the power from the motor (212) is circulated within the motor (212) and the controller (208) itself, thus not pushing any of the currents back to the battery (206) as needed in high SoC scenarios.
[00101] FIG. 10 illustrates a graph (1000) showing the amount of deceleration power that is available through regeneration (shown as hashed lines), and net deceleration power available if dissipation along with the regeneration is taken into account (shown as horizontal lines), in accordance with an embodiment of the disclosure. The disclosed system (201) is capable to arbitrate the power between dissipation and regeneration. The deceleration power may be used in the vehicle in a way such that all the power that is allowed to be regenerated by the battery may be used to charge the battery itself, while the rest of the power may be dissipated. This implies that there is a significant amount of available power across the whole SoC band when dissipation occurs (shown as horizontal lines). This available power may be used for deceleration of the vehicle as compared to the power available only through regeneration (shown as hashed lines) so as to give a more consistent feel to the driver.
[00102] FIG. 11 illustrates a graph (1100) showing an amount of deceleration power that is actually being achieved from the regeneration (shown as hashed lines) which is lesser than the regeneration power shown in FIG. 10 as we add a layer of buffer from the vehicle control unit (402) to stay within safe limits of current sent back to the battery (206), and net deceleration power available (shown as horizontal lines), when dissipation is also taken into account in accordance with an embodiment of the disclosure. This figure is a slice of a 3D plot with its axes being the Power, SoC, and speed. This 2D plot is representative for lower speeds and as the speed increases the amount of power dissipated at lower SoCs also increases until it reaches a pre-defined threshold limit preset by the system (201). As is illustrated, after taking into account the power available from the dissipation and the power available from the regeneration, the net deceleration power available (shown as the horizontal lines) to the vehicle (202) is highly consistent across the whole SoC band. The deceleration power achieved from the regeneration (shown as hashed lines) denotes the power being contributed by the regeneration current. As is observed, the available power is achieved mostly from the dissipation achieved at the high SoCs, however at lower SoCs the regeneration current is being used.
[00103] FIG. 12 illustrates an exemplary method (1200) for consistently controlling speed of the vehicle (202) through the throttle (210), in accordance with an embodiment of the disclosure.
[00104] At step (1202), the method (1200) may include receiving, by a vehicle controller (204), a present state and a maximum allowable charging limit of the battery (206) during regeneration. In some embodiments, the receiving of the present state and the maximum allowable charging limit of the battery (206) may be based on information corresponding to cell voltage, SoC, SoH, a battery temperature, the motor temperature, and the motor controller temperature.
[00105] At step (1204), the method (1200) may include determining, by the vehicle controller (204), a vehicle state. In some embodiments, the determination may be based on HMI inputs and observed changes in vehicle parameters.
[00106] At step (1206), the method (1200) may include transmitting, by the vehicle controller (204), the determined vehicle state and an updated allowable charging limit of the battery (206) to the motor controller (208). In some embodiments, the updated allowable charging limit of the battery (206) may be determined based on a buffer capacity appended to the received maximum allowable charging limit from the battery (206).
[00107] At step (1208), the method (1200) may include obtaining, by the vehicle controller (204), information corresponding to a motor Revolutions Per Minute (RPM), a motor temperature, and a motor controller temperature from the motor controller (208) to determine an amended state of the vehicle (202) and one or more fault states.
[00108] At step (1210), the method (1200) may include further sending, by the vehicle controller (204), the amended state of the vehicle (202) and the one or more fault states to the battery (206) and the motor controller (208).
[00109] FIG. 13 illustrates an exemplary computer system (1300) in which or with which embodiments of the present disclosure may be implemented.
[00110] As shown in FIG. 13, the computer system (1300) may include an external storage device (1310), a bus (1320), a main memory (1330), a read-only memory (1340), a mass storage device (1350), a communication port (1360), and a processor (1370). A person skilled in the art will appreciate that the computer system (1300) may include more than one processor (1370) and communication ports (1360). The processor (1370) may include various modules associated with embodiments of the present disclosure.
[00111] In an embodiment, the communication port (1360) may be any of an RS-232 port for use with a modem-based dialup connection, a 10/100 Ethernet port, a Gigabit or 10 Gigabit port using copper or fiber, a serial port, a parallel port, or other existing or future ports. The communication port (1360) may be chosen depending on a network, such a Local Area Network (LAN), Wide Area Network (WAN), or any network to which the computer system (1300) connects.
[00112] In an embodiment, the memory (1330) may be Random Access Memory (RAM), or any other dynamic storage device commonly known in the art. Read-only memory (1340) may be any static storage device(s) e.g., but not limited to, a Programmable Read Only Memory (PROM) chips for storing static information e.g., start-up or Basic Input/Output System (BIOS) instructions for the processor (1370).
[00113] In an embodiment, the mass storage (1350) may be any current or future mass storage solution, which may be used to store information and/or instructions. Exemplary mass storage solutions include, but are not limited to, Parallel Advanced Technology Attachment (PATA) or Serial Advanced Technology Attachment (SATA) hard disk drives or solid-state drives (internal or external, e.g., having Universal Serial Bus (USB) and/or Firewire interfaces), one or more optical discs, Redundant Array of Independent Disks (RAID) storage, e.g., an array of disks (e.g., SATA arrays).
[00114] While the foregoing describes various embodiments of the disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof. The scope of the disclosure is determined by the claims that follow. The disclosure is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the present disclosure when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF THE PRESENT DISCLOSURE
[00115] The present disclosure provides a braking system for controlling speed of a vehicle through throttle so that deceleration of the vehicle is consistent across all States of Charges (SoCs) of battery and at all speeds of the vehicle.
[00116] The present disclosure provides the throttle which can move on both positive side and negative side of a neutral point. Movement on the positive side signifies positive acceleration, while the movement on the negative side signifies negative or deceleration torque.
[00117] The present disclosure provides a mechanism to tune the torque - Rotation Per Minute (RPM) maps by taking into account rolling resistance and air drag features that have a consistent deceleration number across the whole RPM range.
[00118] The present disclosure provides facilitates to arbitrate between dissipated power and regenerated power, such that the regenerated power from the battery is used to charge the battery and the rest is discarded. This allows availability of a significant amount of power across a whole SoC band to be used during dissipation for deceleration of the vehicle.
List of References:
System (201)
Vehicle (202)
Vehicle Controller (204)
Battery (206)
Motor Controller (208)
Throttle (210)
Motor (212)
Rear wheel (214)
Processor(s) (302)
Memory (304)
Interface(s) (306)
Processing Module(s) (308)
Receiving Module (310)
Determination Module (312)
Transmitting Module (314)
Acquisition Module (316)
Other Module(s) (318)
Database (322)
Vehicle Control Unit (IMU) (402)
,CLAIMS:1. A method (1200) for consistently controlling speed of a vehicle (202) through a throttle (210), the method (1200) comprising:
receiving, by a vehicle controller (204), a present state and a maximum allowable charging limit of a battery (206) during regeneration;
determining, by the vehicle controller (204), a vehicle state;
transmitting, by the vehicle controller (204), the determined vehicle state and an updated allowable charging limit of the battery (206) to a motor controller (208);
obtaining, by the vehicle controller (204), information corresponding to a motor Revolutions Per Minute (RPM), a motor temperature, and a motor controller temperature from the motor controller (208) to determine an amended state of the vehicle (202) and one or more fault states; and
sending, by the vehicle controller (204), the amended state of the vehicle (202) and the one or more fault states to the battery (206) and the motor controller (208).
2. The method (1200) as claimed in claim 1, wherein receiving, by the vehicle controller (204), the present state and the maximum allowable charging limit of the battery (206) is based on information corresponding to cell voltage, States of Charge (SoC), States of Health (SoH), a battery temperature, the motor temperature, and the motor controller temperature.
3. The method (1200) as claimed in claim 1, wherein deceleration power is routed to dissipation when States of Charge (SoC) of the battery (206) is high, and wherein the deceleration power is routed to regeneration when the SoC of the battery (206) is low.
4. The method (1200) as claimed in claim 1, wherein upon deceleration power being routed to dissipation when States of Charge (SoC) of the battery (206) is high, a consistent vehicle deceleration is achieved.
5. The method (1200) as claimed in claim 1, wherein the vehicle state is determined based on one or more Human-Machine Interface (HMI) inputs and observed changes in one or more vehicle parameters, and wherein the updated allowable charging limit of the battery (206) is determined based on a buffer capacity appended to the received maximum allowable charging limit from the battery (206).
6. The method (1200) as claimed in claim 1, wherein an angular displacement of the throttle (210), based on one or more Human-Machine Interface (HMI) inputs is performed by the vehicle controller (204), and wherein a positive input generates an acceleration torque and a negative input generates a deceleration torque.
7. The method (1200) as claimed in claim 1, wherein a buffer capacity is appended by the vehicle controller (204) to the received maximum allowable charging limit from the battery (206) to accommodate estimation and calibration errors.
8. The method (1200) as claimed in claim 1, wherein the motor controller (208) selects a torque value from a lookup table based on the determined vehicle state and the motor RPM.
9. The method (1200) as claimed in claim 1, comprising tuning, by the vehicle controller (204), a vehicle torque based on predetermined values provided in a lookup table, wherein the lookup table comprises a unique torque value with respect to each motor RPM value of the vehicle (202).
10. The method (1200) as claimed in claim 1, comprising dynamically adjusting, by the vehicle controller (204), one or more entries of a lookup table based on a determined decelerating effect of a motor (212), air drag, and rolling resistance on the vehicle (202), for consistently controlling the speed of the vehicle (202).
11. The method (1200) as claimed in claim 1, comprising determining, by the vehicle controller (204), a reference value to control the motor controller (208) to obtain and control at least one of a combination of a unique torque value and a generated regenerative power simultaneously.
12. The method (1200) as claimed in claim 1, comprising arbitrating, by the vehicle controller (204), between dissipated power and a generated regenerative power, wherein an allowable limit of the generated regenerative power is used to charge the battery (206).
13. A braking system (201) for consistently controlling speed of a vehicle (202) through a throttle, the system (201) comprising:
one or more vehicle controllers (204); and
a memory coupled to the one or more vehicle controllers (204), the memory comprising one or more vehicle controller-executable instructions which, when executed, cause the one or more vehicle controllers (204) to:
receive a present state and a maximum allowable charging limit of a battery (206) during regeneration;
determine a vehicle state;
transmit the determined vehicle state and an updated allowable charging limit of the battery to a motor controller (208);
obtain information corresponding to a motor Revolutions Per Minute (RPM), a motor temperature, and a motor controller temperature from the motor controller (208) to determine an amended state of the vehicle (202) and one or more fault states; and
send the amended state of the vehicle (202) and the one or more fault states to the battery (206) and the motor controller (208).
14. The system (201) as claimed in claim 13, wherein deceleration power is routed to dissipation when States of Charge (SoC) of the battery (206) is high, and wherein the deceleration power is routed to regeneration when the SoC of the battery (206) is low.
15. The system (201) as claimed in claim 13, wherein upon deceleration power being routed to dissipation when States of Charge (SoC) of the battery (206) is high, a consistent vehicle deceleration is achieved.
16. The system (201) as claimed in claim 13, wherein the vehicle state is determined based on one or more Human-Machine Interface (HMI) inputs and observed changes in one or more vehicle parameters, and wherein the updated allowable charging limit of the battery (206) is determined based on a buffer capacity appended to the received maximum allowable charging limit from the battery (206).
17. The system (201) as claimed in claim 13, wherein a buffer capacity is appended to the received maximum allowable charging limit from the battery (206) to accommodate estimation and calibration errors.
18. The system (201) as claimed in claim 13, wherein the motor controller (208) selects a torque value from a lookup table based on the determined vehicle state and the motor RPM.
19. The system (201) as claimed in claim 13, comprising: tuning a vehicle torque based on predetermined values provided in a lookup table, wherein the lookup table comprises a unique torque value with respect to each motor RPM value of the vehicle (202).
20. The system (201) as claimed in claim 13, comprising:
dynamically adjusting one or more entries of a lookup table based on a determined decelerating effect of a motor (212), air drag, and rolling resistance on the vehicle (202), for consistently controlling the speed of the vehicle (202).