DESC:SYSTEM FOR ENABLING ENGINE BRAKING IN GEAR-BASED ELECTRIC VEHICLES
CROSS REFERENCE TO RELATED APPLICTIONS
The present application claims priority from Indian Provisional Patent Application No. 202421001202 filed on 06-01-2024, the entirety of which is incorporated herein by a reference.
TECHNICAL FIELD
The present disclosure generally relates to electric vehicles. Further, the present disclosure particularly relates to enabling engine braking in gear-based electric vehicles.
BACKGROUND
Electric vehicles (EVs) have become a pivotal solution in the transition towards sustainable transportation systems, offering significant advantages over traditional internal combustion engine (IC engine) vehicles. EVs operate using electric motors powered by energy storage systems, such as rechargeable batteries, which eliminate the need for fossil fuels and reduce greenhouse gas emissions. The increasing adoption of EVs is driven by technological advancements in battery chemistry, energy density, motor efficiency, and power electronics, coupled with growing environmental awareness and regulatory support for reducing carbon footprints. EVs also provide additional benefits, such as smooth and noiseless operation, reduced maintenance requirements due to fewer moving parts, and the potential for energy recovery through regenerative braking systems. These attributes make EVs a prominent choice for personal, commercial, and industrial applications.
The drivetrain configurations of EVs are a critical aspect of their performance, particularly in gear-based systems. Unlike single-speed drivetrains, gear-based systems allow for better utilization of motor torque across a range of speeds, enhancing efficiency and driving dynamics. However, gear-based EVs also introduce complexities, especially during gear transitions. A significant challenge arises during abrupt gear changes, such as single or double downshifts, which can cause a sudden increase in the rotational speed of the motor, commonly referred to as RPM shoot-up. Such a phenomenon is inherently different in EVs compared to IC engine vehicles. In IC engines, the mechanical load imposed by the engine naturally limits the speed increase during downshifting. In contrast, the lower mechanical damping of electric motors makes them more vulnerable to excessive RPM increases, which can lead to operational inefficiencies and potential damage to the components.
The RPM shoot-up in EVs during downshifting poses several challenges. The rapid increase in motor speed can impose significant stress on the motor, leading to overheating or accelerated wear. More critically, the high-speed operation of the motor can transfer excessive stress to the inverter system, which manages the conversion of electrical energy between the motor and the battery. Such stress can result in failures of the inverter system, impacting the reliability of the EV drivetrain. Additionally, prolonged operation at elevated RPMs may reduce the lifespan of motor bearings and other associated components, increasing maintenance costs and downtime.
To mitigate the effects of RPM shoot-ups, EVs commonly incorporate regeneration mechanisms that capture the kinetic energy of the motor during deceleration and convert the captured kinetic energy into electrical energy for storage in the battery. The process, referred to as regenerative braking, serves a dual purpose: slowing down the motor to prevent excessive RPMs and improving overall energy efficiency by recovering otherwise wasted kinetic energy. However, existing systems for regenerative braking face limitations in effectively regulating motor speed during sudden gear changes. The activation of regenerative braking often lacks synchronization with real-time parameters such as the state of charge (SOC) of the battery or the allowable charging current. In cases where the battery is near full capacity, improper activation of regenerative braking may lead to overcharging, which can damage the battery or compromise safety.
Another limitation of conventional systems is the inability to dynamically adapt to varying load conditions. Existing systems often rely on predefined thresholds to trigger regenerative braking, which may not account for the complex and dynamic interplay of factors such as motor torque, vehicle speed, and operator input. The lack of coordination between motor speed monitoring, battery management, and regeneration mechanisms reduces the effectiveness of the braking system, particularly during high-stress scenarios such as rapid downshifts or emergency braking.
The absence of a robust and integrated approach to managing RPM shoot-ups in gear-based EVs underscores the need for advanced solutions. Such solutions should prevent excessive motor speeds during downshifting and optimize energy recovery through seamless integration with battery management systems. Addressing these challenges is important for enhancing the safety, reliability, and performance of gear-based EVs in diverse operating conditions.
SUMMARY
The aim of the present disclosure is to provide a system to enable engine braking in a gear-based electric vehicle (EV) for enhancing the safety, reliability, and performance of gear-based EVs in diverse operating conditions.
The present disclosure relates to a system for enabling engine braking in a gear-based EV. Said system comprises a motor to drive the vehicle, a battery management system to monitor a state of charge, charging current, and current output of a powerpack, a throttle demand sensing unit to sense operator throttle input, and a control unit. The control unit determines a motor RPM value and enables engine braking to reduce the RPM below a predefined level. Such engine braking is enabled upon determining each of the following: the state of charge of the powerpack is below a predefined threshold, the battery management system allows charging at the defined current, and the detected motor RPM exceeds the predefined level.
In another aspect, the present disclosure provides that the control unit disables engine braking upon detecting at least one of the following: the state of charge of the powerpack exceeds the predefined threshold, the battery management system disallows charging of the powerpack at the defined current, or the detected motor RPM is below the predefined level.
Furthermore, the present disclosure provides that the control unit disables throttle input during engine braking until detection of at least one of the following: the state of charge of the powerpack exceeds the predefined threshold, the battery management system disallows charging of the powerpack at the defined current, or the detected motor RPM is below the predefined level. Disabling the throttle input during braking prevents simultaneous throttle application and braking, thereby safeguarding the system and enabling effective deceleration of the vehicle.
Moreover, the present disclosure provides that the control unit calibrates the predefined threshold values for engine braking based on a selected driving mode. Calibration of thresholds enables the system to adapt engine braking to varying driving conditions such as urban, highway, or off-road scenarios. Such adaptability enhances the flexibility and reliability of the system under diverse operational conditions.
Additionally, the present disclosure provides that the control unit enables continuous regeneration of high charging current during engine braking. Continuous regeneration during braking facilitates the conversion of kinetic energy into electrical energy for storage in the powerpack. Such regeneration reduces energy wastage, enhances energy recovery, and prevents the motor from operating at excessive RPMs for prolonged durations.
In a further aspect, the present disclosure provides a method for enabling engine braking in a gear-based EV. Said method comprises monitoring a state of charge, charging current, and output current of a powerpack using a battery management system, utilizing a motor to drive the vehicle, sensing throttle input through a throttle demand sensing unit, determining a motor RPM value, and enabling engine braking. Such enabling is performed upon determining that the state of charge is below a predefined threshold, the battery management system allows charging at the defined current, and the detected RPM value exceeds the predefined level. Said method provides a structured approach to regulating motor speed, preventing over speeding, and improving safety.
Moreover, the present disclosure provides that the control unit disables throttle input during engine braking until detecting at least one of the following: the state of charge of the powerpack exceeds the predefined threshold, the battery management system disallows charging of the powerpack at the defined current, or the detected motor RPM is below the predefined level.
Furthermore, the present disclosure provides that the control unit calibrates the predefined threshold for enabling engine braking based on a selected driving mode. Calibration of thresholds for different driving modes enables the method to accommodate variations in driving environments such as urban, highway, or hilly terrains.
Additionally, the present disclosure provides that the control unit enables continuous regeneration of high charging current during engine braking. Such continuous regeneration allows for efficient energy recovery by converting the kinetic energy of the motor into electrical energy for storage in the powerpack.
BRIEF DESCRIPTION OF DRAWINGS
The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the present disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated by identical numbers.
Embodiments of the present disclosure will now be described, by way of example only, with reference to the following diagrams wherein:
FIG. 1 illustrates a system 100 for enabling engine braking in a gear-based electric vehicle (EV), in accordance with the embodiments of the present disclosure.
FIG. 2 illustrates a method 200 for enabling an engine braking in a gear-based electric vehicle (EV), in accordance with the embodiments of the present disclosure.
FIG. 3 illustrates a flow diagram of a system 100 for enabling engine braking in a gear-based electric vehicle (EV), in accordance with the embodiments of the present disclosure.
In the accompanying drawings, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non-underlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is pointing.
DETAILED DESCRIPTION
The following detailed description illustrates embodiments of the present disclosure and ways in which they can be implemented. Although some modes of carrying out the present disclosure have been disclosed, those skilled in the art would recognise that other embodiments for carrying out or practising the present disclosure are also possible.
The description set forth below in connection with the appended drawings is intended as a description of certain embodiments of a motor of an electric vehicle and is not intended to represent the only forms that may be developed or utilised. The description sets forth the various structures and/or functions in connection with the illustrated embodiments; however, it is to be understood that the disclosed embodiments are merely exemplary of the disclosure that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimised to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.
The terms “comprise”, “comprises”, “comprising”, “comprise(s)”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, system that comprises a list of components or steps does not comprise only those components or steps but may comprise other components or steps not expressly listed or inherent to such setup or system. In other words, one or more elements in a system or apparatus preceded by “comprises... a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus.
In the following detailed description of the embodiments of the disclosure, reference is made to the accompanying drawings, and which are shown by way of illustration specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.
The present disclosure will be described herein below with reference to the accompanying drawings. In the following description, well known functions or constructions are not described in detail since they would obscure the description with unnecessary detail.
As used herein, the term "motor" refers to an electromechanical device that converts electrical energy into mechanical energy to generate torque for driving a system, such as a vehicle. A motor typically consists of a stator, rotor, and windings. Electrical current passing through the windings interacts with magnetic fields to produce rotational motion. The motor can be selected from direct current (DC) motors such as brushed or brushless DC motors, alternating current (AC) motors such as induction motors and synchronous motors, or permanent magnet motors.
As used herein, the term "battery management system" refers to an electronic control and monitoring system manages and regulates the operation, safety, and lifecycle of a rechargeable power source, such as a battery pack. A battery management system monitors parameters such as state of charge (SOC), voltage, charging current, discharging current, temperature, and cell health. For example, in lithium-ion battery packs, the battery management system prevents condition in which cell exceeds the voltage limit during charging and no cell drops below the minimum voltage during discharging to prevent deep discharge. The battery management system incorporates sensors such as current sensors to measure the flow of current, voltage sensors to track individual cell voltages, and temperature sensors to monitor thermal conditions. A battery management system interacts with other components, such as the control unit and motor controller, to regulate energy use and maintain operational safety.
As used herein, the term "state of charge" refers to the measure of the energy level remaining in a battery relative to the total capacity, expressed as a percentage. State of charge is an important parameter for energy management in EVs, as said state of charge indicates the remaining operational energy. For instance, a lithium-ion battery with an 80% state of charge indicates that 80% of the usable energy capacity is available for operation. Methods for estimating state of charge comprise Coulomb counting and open circuit voltage measurement.
As used herein, the term "charging current" refers to the electric current supplied to a battery during the charging process to restore the energy. Charging current is measured in amperes and depends on the battery type, capacity, and charging conditions. For example, a lithium-ion battery may be charged at a constant current of 5 amperes until a specified voltage is reached. Regulating the charging current prevents overheating, overcharging, and reducing the risk of battery degradation.
As used herein, the term "current output" refers to the electric current delivered by a power source, such as a battery pack, to a connected load or system component. Current output is typically expressed in amperes and fluctuates based on the load demand of system. For example, during vehicle acceleration, the current output from the battery increases to meet the power requirements of motor. Sensors within the battery management system monitor the current output to detect overcurrent conditions or enable sufficient energy delivery to the motor and other components.
As used herein, the term "RPM value" refers to the rotational speed of a motor or rotating component, expressed in revolutions per minute. RPM value indicates the number of complete rotations performed by a rotor of motor within one minute. For example, in a gear-based EV, an RPM value of 3,000 corresponds to moderate vehicle speed. Sensors such as Hall effect sensors or optical encoders are used to monitor RPM values.
As used herein, the term "predefined level" refers to a specific threshold value set for a parameter within the system, beyond which predefined actions are initiated. A predefined level is determined based on system design and operational requirements. For example, a predefined level for motor RPM may be set at 5,000 revolutions per minute to prevent mechanical stress or overheating. Similarly, a predefined level for the state of charge may be set at 20% to trigger energy conservation mechanisms. Predefined levels are monitored dynamically to maintain safe and efficient system operation.
As used herein, the term "regeneration" refers to the process of converting kinetic energy into electrical energy during braking or deceleration and storing it in a battery. Regeneration typically involves operating a motor in reverse to act as a generator. For instance, when an EV decelerates, the motor converts rotational energy into electrical energy, which is then stored in the battery. Regeneration helps conserve energy, control motor speed, and reduce energy wastage during operation.
As used herein, the term "driving mode" refers to a set of predefined operating parameters that determine the performance characteristics of a vehicle based on specific conditions or preferences. Examples of driving modes comprise economy mode, sport mode, or off-road mode. Economy mode may prioritize reduced energy consumption, while sport mode may focus on higher performance and torque delivery.
FIG. 1 illustrates a system 100 for enabling engine braking in a gear-based electric vehicle (EV), in accordance with the embodiments of the present disclosure. The system 100 comprises a motor 102 configured to drive the EV. The motor 102 operates as electromechanical device, converting electrical energy into mechanical energy to generate the torque required to propel the vehicle. The motor 102 consists of essential components such as rotor, stator, and associated windings. Upon receiving electrical input, the rotor rotates to produce the mechanical force necessary to drive the drivetrain of the EV. The motor 102 is capable of bidirectional operation, enabling forward and reverse movement as required by the operational demands of vehicle. Additionally, the motor 102 operates across a range of rotational speeds, depending on load conditions and the input received from the control unit 108. The motor 102 is integrated with mechanisms to measure the rotational speed (RPM value), which activates engine braking. Various motor types, such as brushless DC motors or synchronous motors, can be employed, with selection based on the power requirements and performance criteria of vehicle.
In an embodiment, the system 100 comprises a battery management system (BMS) 104, which monitors the parameters associated with the powerpack of the vehicle. The BMS 104 measures the state of charge (SOC), which indicates the percentage of energy remaining in the battery relative to the maximum capacity. The BMS 104 also monitors the charging current provided to the battery and the output current supplied by the powerpack to the motor 102 and other subsystems. Sensors integrated within the BMS 104 measure said parameters in real time, enabling the detection of conditions such as overcharging, over-discharging, or abnormal temperature variations. The BMS 104 communicates the data to a control unit 108, assuring that engine braking is activated only under permissible conditions. For instance, the BMS 104 allows charging of the powerpack at the defined current if the SOC is below a predefined threshold, affirming that regeneration during engine braking does not result in overcharging or battery damage.
In an embodiment, the system 100 further comprises a throttle demand sensing unit 106 that detects input from the vehicle operator. The throttle demand sensing unit 106 measures the position of a throttle control, such as a pedal or lever, to determine the level of acceleration or deceleration intended by the operator. The sensing unit 106 utilizes devices such as potentiometers, Hall effect sensors, or optical sensors to generate signals proportional to the throttle input. The throttle input signal is transmitted to the control unit 108, which uses it to regulate motor power and manage vehicle speed. During engine braking, the throttle demand sensing unit 106 makes sure that the motor 102 does not receive conflicting acceleration commands. The throttle demand sensing unit 106 also comprises mechanisms to detect anomalies, such as unintended input or faults in the sensing system, affirming that only valid throttle signals are processed during operation.
In an embodiment, the system 100 comprises a control unit 108 that orchestrates the coordination between various components. The control unit 108 receives input from the BMS 104, throttle demand sensing unit 106, and sensors monitoring the RPM value of the motor 102. Based on the collected data, the control unit 108 determines whether engine braking is required. If the RPM value of the motor 102 exceeds a predefined level, the control unit 108 evaluates additional conditions before activating engine braking. These conditions comprise verifying that the SOC of the powerpack is below the predefined threshold and confirming that the BMS 104 allows charging of the powerpack at the charging current. Upon satisfying these conditions, the control unit 108 activates engine braking by initiating regeneration, thereby converting the kinetic energy of the motor 102 into electrical energy to be stored in the powerpack.
In an embodiment, the engine braking functionality implemented by the control unit 108 helps regulate the speed of the motor 102 and prevents the RPM value from exceeding safe operating limits. By monitoring the predefined threshold levels for SOC and RPM, the control unit 108 enables that regeneration occurs under optimal conditions. Additionally, the control unit 108 coordinates with the throttle demand sensing unit 106 to disable throttle input during engine braking, preventing simultaneous acceleration and deceleration commands. Such functionality contributes to the safe and controlled deceleration of the vehicle, protecting the motor 102 and other subsystems from damage due to excessive speeds or conflicting inputs.
In an embodiment, the predefined levels referenced in the system 100 are established based on the design and operational requirements of vehicle. For example, the predefined level for motor RPM may correspond to the maximum safe rotational speed, above which the motor 102 may experience mechanical or thermal stress. Similarly, the predefined threshold for the SOC assures that the powerpack retains sufficient capacity to accept additional energy during regeneration without exceeding the safe operational limits. The thresholds are adjustable and may vary depending on factors such as the driving mode of vehicle, road conditions, or operator preferences.
In an exemplary aspect, a system 100 for enabling engine braking in a gear-based EV is utilized during a downhill driving scenario. The gear-based EV is traveling at a speed of 60 km/h, with the motor 102 generating torque to maintain the propulsion of vehicle. At said speed, the motor 102 operates at an RPM value of 4,200. The operator releases the throttle pedal, signalling a reduction in speed. The throttle demand sensing unit 106 detects the absence of throttle input and transmits the corresponding signal to the control unit 108. Simultaneously, the BMS 104 monitors parameters of the powerpack, including the SOC, which is measured at 42%, and the charging current capacity, which is indicated as 15 amperes.
The predefined SOC threshold for enabling engine braking is set at 50%, and the control unit 108 evaluates the conditions for activation. The control unit 108 determines that the SOC of the powerpack is below the predefined threshold, allowing the battery to accept additional energy generated during regeneration. Additionally, the detected motor RPM value of 4,200 exceeds the predefined RPM threshold of 3,500. The BMS 104 confirms that the powerpack is capable of charging at the specified charging current. With all conditions satisfied, the control unit 108 enables engine braking to reduce the motor RPM value below the predefined threshold of 3,500.
Upon activation of engine braking, the motor 102 transitions into regeneration mode, converting the kinetic energy of the drivetrain into electrical energy. The electrical energy is stored in the powerpack under the continuous supervision of the BMS 104. During regeneration, the motor RPM gradually decreases from 4,200 to 2,800, resulting in a reduction in vehicle speed from 60 km/h to 40 km/h. The throttle demand sensing unit 106 makes sure that no conflicting throttle input interferes with the braking operation. The control unit 108 continuously monitors the SOC, RPM value, and charging current during the braking process, maintaining engine braking until the motor RPM value stabilizes below the predefined threshold, at which point engine braking is disabled.
In an embodiment, the control unit 108 may disable engine braking upon detecting at least one of the following conditions: the determined SOC of the powerpack exceeds a predefined threshold, the battery BMS 104 disallows charging of the powerpack at the charging current, or the detected RPM value of the motor 102 is less than a predefined level. The control unit 108 continuously monitors these parameters during operation. For instance, when the SOC of the powerpack reaches 85%, exceeding the predefined threshold of 80%, the control unit 108 disables engine braking to prevent overcharging of the powerpack during regeneration. Similarly, if the BMS 104 identifies that the charging current of the powerpack has exceeded the allowable limits, such as 20 amperes, the control unit 108 disables engine braking to avoid causing stress to the battery. Additionally, if the motor RPM value drops below the predefined threshold, the control unit 108 stops engine braking to prevent unnecessary regeneration, which might hinder smooth motor operation. The control unit 108 evaluates these conditions dynamically based on the data received from the BMS 104 and the sensors monitoring the motor 102.
In an embodiment, the control unit 108 may disable throttle input during engine braking until detecting at least one of the following conditions: the determined SOC of the powerpack exceeds a predefined threshold, the BMS 104 disallows charging of the powerpack at the charging current, or the detected RPM value of the motor 102 is less than a predefined level. For example, when engine braking is engaged, the control unit 108 temporarily overrides input from the throttle demand sensing unit 106 to avoid conflicting commands during deceleration. During said period, if the SOC of the powerpack exceeds the predefined threshold, such as 85%, the control unit 108 stops disabling throttle input and allows normal throttle operation to resume. Similarly, if the BMS 104 disallows charging of the powerpack due to conditions like overcurrent or high battery temperature, the control unit 108 disables engine braking and enables throttle input again. Additionally, if the RPM value of the motor 102 drops below a predefined threshold, the control unit 108 concludes that engine braking is no longer necessary and restores control to the throttle demand sensing unit 106.
In an embodiment, the control unit 108 may calibrates the predefined threshold based on a selected driving mode. The driving mode may be chosen by the operator or adjusted automatically by the system 100 depending on road conditions and operational requirements. For example, in an economy mode, the control unit 108 sets lower RPM thresholds and higher SOC thresholds to maximize energy recovery during engine braking. In contrast, in a sport mode, the control unit 108 allows higher RPM thresholds and lower SOC thresholds to provide responsive braking performance while maintaining optimal energy management. Additionally, in off-road driving modes, the control unit 108 adjusts the predefined thresholds to account for conditions such as uneven terrain, where regenerative braking needs to be more controlled to prevent abrupt deceleration. The control unit 108 dynamically adjusts parameters such as the allowable charging current, SOC thresholds, and RPM levels based on the driving mode. For instance, during urban driving, the predefined RPM threshold may be set at 2,500 RPM, while in highway driving, said predefined RPM threshold may be increased to 4,000 RPM. Said calibrated thresholds are implemented in real time by the control unit 108 so that engine braking aligns with the specific requirements of the selected driving mode. Table. 1 depicts exemplary driving modes (and their pre-set thresholds) that can be chosen by the operator.
Vehicle Mode Motor Max RPM RPM Threshold for Activating Engine Braking RPM Threshold for Deactivating Engine Braking
ECO 3200-3700 Above 3800-4300 Below 2800-3200
CITY 3900-4200 Above 4400-4800 Below 3400-3800
SPORT 5400-5800 Above 6200-6600 Below 4900-5300
Table. 1
As illustrated in Table 1, the motor RPM thresholds for activating and deactivating engine braking vary across three driving modes: ECO, CITY, and SPORT. The ECO mode is energy-efficient driving mode, the motor operates within a maximum RPM range of 3200-3700, with engine braking activated above 3800-4300 RPM and deactivated below 2800-3200 RPM. The CITY mode, for urban conditions, supports a motor RPM range of 3900-4200, with activation above 4400-4800 RPM and deactivation below 3400-3800 RPM. The SPORT mode, optimized for performance, allows a maximum RPM of 5400-5800, with activation above 6200-6600 RPM and deactivation below 4900-5300 RPM.
In an embodiment, the control unit 108 may enable a continuous regeneration of high charging current during engine braking. When the control unit 108 engages engine braking, the motor 102 operates in regeneration mode to convert the kinetic energy of vehicle into electrical energy, which is then stored in the powerpack. The control unit 108 affirms that the charging current remains within a high predefined range, such as 15 to 20 amperes, throughout the duration of engine braking. The functionality is particularly useful during extended downhill driving, where continuous braking is required to control the speed of vehicle while maximizing energy recovery. The BMS 104 monitors the charging current in real time and communicates with the control unit 108 to make sure the charging process remains within permissible limits. For example, if the SOC of the powerpack approaches the predefined maximum threshold of 90%, the control unit 108 dynamically reduces the charging current to prevent overcharging. The continuous regeneration of high charging current during engine braking allows the system 100 to achieve effective deceleration while recovering significant amounts of energy. The control unit 108 actively manages the interaction between the motor 102 and the BMS 104 to maintain safe and consistent energy flow to the powerpack during prolonged regenerative braking events.
In an embodiment, the control unit 108 accesses a stored RPM value of the motor 102. The stored RPM value corresponds to data sensed at a prior instance and recorded in a storage unit (e.g., memory device), along with an associated timestamp indicating the time of sensing. The storage unit stores the sensed RPM value in a structured manner, enabling retrieval of the RPM value when required. Accessing a stored RPM value instead of obtaining real-time RPM data from the motor 102 would be advantageous by reducing potential latency caused by data transmission over the Controller Area Network (CAN) bus. For instance, in scenarios where the CAN bus is heavily loaded with data packets, real-time data acquisition can experience delays, leading to slower response times. By leveraging previously stored RPM data, the system 100 avoids such delays, enabling prompt computation and action by the control unit 108. The use of stored RPM data improves the efficiency of control decisions, particularly in dynamic operational conditions requiring rapid response, such as enabling engine braking during deceleration. Optionally, the timestamp associated with the stored RPM value allows the control unit 108 to validate the recency of the stored data before using it for computations. If the data is determined to be outdated, real-time data acquisition can be initiated as a fallback measure. When a vehicle transitions from acceleration to deceleration, the control unit 108 retrieves the RPM value stored two seconds earlier, which is timestamped and stored in the storage unit. Based on this data, the control unit 108 initiates engine braking without experiencing delays caused by waiting for real-time RPM data through the CAN bus.
In an embodiment, the control unit 108 determines the RPM value of the motor 102 by retrieving the most recently stored RPM value from the storage unit. The stored RPM value is directly accessed by the control unit 108 to eliminate requirement of query real-time RPM data through the CAN bus. Such configuration enables that delays resulting from transmission bottlenecks on the CAN bus are avoided to improve responsiveness during critical operations, such as reducing motor RPM for enabling engine braking. Optionally, the control unit 108 can compare multiple stored RPM values to detect trends or patterns before determining the current motor RPM value. Such an approach enhances decision-making in cases where transient motor behaviour needs to be accounted for. For instance, during an emergency braking scenario, the control unit 108 accesses the last stored RPM value of the motor 102 from the storage unit, timestamped one second prior. Based on this value, the control unit 108 initiates engine braking without waiting for real-time RPM data, thereby rapid deceleration of the vehicle.
FIG. 2 illustrates a method 200 for enabling an engine braking in a gear-based electric vehicle (EV), in accordance with the embodiments of the present disclosure. At step 202, the method 200 involves monitoring, through a battery management system (BMS) 104, parameters of a powerpack associated with a gear-based EV. The BMS 104 continuously monitors the SOC, which represents the energy level of the powerpack relative to the maximum capacity. Additionally, the BMS 104 monitors the charging current supplied to the powerpack during charging operations and the current output delivered by the powerpack to connected systems, including the motor 102. Sensors integrated into the BMS 104 measure real-time data related to these parameters and provide the data to the control unit 108 for evaluation. The BMS 104 also verifies whether the powerpack remains within predefined safety thresholds, affirming that charging and discharging operations occur under permissible conditions.
At step 204, the method 200 involves utilizing the motor 102 to drive the gear-based EV. The motor 102 receives electrical energy from the powerpack and converts the received electrical energy into mechanical energy to propel the vehicle. The motor 102 generates torque based on operator input and operational conditions, transmitting the torque to the drivetrain of vehicle to enable forward or reverse movement. The motor 102 operates across a range of rotational speeds (RPM values) depending on the load conditions and power requirements.
At step 206, the method 200 involves sensing, through a throttle demand sensing unit 106, throttle input provided by the operator. The throttle demand sensing unit 106 detects the position or movement of the throttle control, such as a pedal or lever, and generates a signal corresponding to the intended acceleration or deceleration. The sensing unit 106 utilizes position sensors, such as Hall effect sensors or potentiometers, to measure the throttle input accurately. The throttle input signal is transmitted to the control unit 108, which uses the data to regulate the power supplied to the motor 102 and, if necessary, to activate or deactivate engine braking.
At step 208, the method 200 involves determining the RPM value of the motor 102 using sensors integrated with or associated with the motor 102. The RPM value indicates the rotational speed of the motor 102, expressed in revolutions per minute. Sensors such as Hall effect sensors or optical encoders measure the RPM value of motor and provide the data to the control unit 108. The control unit 108 evaluates the RPM value to determine whether said RPM value exceeds a predefined level, which would indicate the need for engine braking to prevent excessive motor speeds or system stress.
At step 210, the method 200 involves enabling engine braking through the control unit 108 based on the data received from the BMS 104, throttle demand sensing unit 106, and motor 102. The control unit 108 evaluates multiple conditions before enabling engine braking, including verifying that the determined SOC of the powerpack is below a predefined threshold, such as 80%. The control unit 108 also confirms that the BMS 104 allows charging of the powerpack at the charging current, assuring that regenerative energy from the motor 102 can be safely stored in the powerpack. Additionally, the control unit 108 assures that the detected RPM value of the motor 102 exceeds the predefined level, indicating the need for deceleration. Upon satisfying all these conditions, the control unit 108 activates engine braking by transitioning the motor 102 into regeneration mode, converting kinetic energy into electrical energy to slow the vehicle while storing the generated energy in the powerpack.
In an embodiment, the control unit 108 may disable the throttle input during engine braking until detecting at least one of the following conditions: the determined SOC of the powerpack exceeds a predefined threshold, the battery management system (BMS) 104 disallows charging of the powerpack at the charging current, or the detected RPM value of the motor 102 falls below the predefined level. When engine braking is activated, the throttle input is temporarily overridden to prevent conflicting acceleration commands while the vehicle is decelerating. For instance, when the SOC of the powerpack exceeds a threshold such as 90%, the control unit 108 disables the throttle override to affirm that engine braking is not unnecessarily maintained, thereby allowing normal throttle input to resume. Similarly, if the BMS 104 determines that charging of the powerpack is no longer permissible due to safety considerations such as overcurrent or excessive temperature, the control unit 108 stops overriding the throttle input. Additionally, if the motor 102 RPM value decreases below the predefined threshold, the control unit 108 concludes that further braking is unnecessary and reinstates normal throttle operation.
In an embodiment, the control unit 108 may calibrate the predefined threshold based on a selected driving mode. The driving mode can be specified by the operator or automatically determined based on the operating environment and requirements of vehicle. For instance, in an economy driving mode, the control unit 108 adjusts the SOC threshold to a lower value, such as 70%, to maximize energy recovery through regenerative braking. Similarly, the RPM threshold in economy mode may be set to a moderate value, such as 2,500 RPM, to prioritize efficient energy utilization. In contrast, in a sport mode, the SOC threshold may be increased to 85% to allow for more aggressive braking dynamics, and the RPM threshold may be raised to 4,000 RPM to support higher performance demands. In off-road mode, the calibration may comprise setting thresholds for terrain conditions, affirming controlled braking on uneven or slippery surfaces. The control unit 108 dynamically adjusts the SOC, RPM, and charging current thresholds during operation, based on the selected driving mode, to achieve optimal braking and energy management. For example, during urban driving, where frequent stops are required, the calibration may favour lower RPM thresholds for smoother deceleration, while in highway driving, the thresholds may be adjusted for extended regeneration.
In an embodiment, the control unit 108 may enable a continuous regeneration of high charging current during engine braking. When engine braking is activated, the motor 102 transitions into a regenerative mode, converting the kinetic energy of vehicle into electrical energy for storage in the powerpack. The control unit 108 actively manages the charging current, maintaining a high predefined range such as 15 to 20 amperes, to maximize energy recovery while enabling system safety. During prolonged braking scenarios, such as descending a steep slope, the continuous regeneration allows the powerpack to store significant amounts of electrical energy without exceeding safety limits. The BMS 104 monitors the charging process in real time, assuring that the charging current remains within permissible levels and preventing overcharging of the powerpack. For instance, if the SOC of the powerpack approaches 95%, the control unit 108 may adjust the regeneration parameters to limit the charging current and avoid battery stress. Said method enables the system 100 to achieve effective deceleration while recovering energy that can be reused during subsequent vehicle operations.
FIG. 3 illustrates a flow diagram of a system 100 for enabling engine braking in a gear-based electric vehicle (EV), in accordance with the embodiments of the present disclosure. The system 100 interacts with a motor 102, a battery management system (BMS) 104, a throttle demand sensing unit 106, and a control unit 108 to manage engine braking dynamically. The process begins when the throttle demand sensing unit 106 detects a throttle input from an operator and transmits the data to the control unit 108. Simultaneously, the control unit 108 retrieves the RPM value of the motor 102. If the RPM value exceeds a predefined threshold, the control unit 108 evaluates the SOC of the powerpack, monitored by the BMS 104. The control unit 108 verifies whether the SOC is below a predefined threshold and further checks if the BMS 104 permits charging of the powerpack at the current charging rate. Upon confirming both conditions, the control unit 108 enables engine braking, allowing the motor 102 to enter a regenerative braking mode, where kinetic energy of the EV is converted into electrical energy. Such electrical energy is stored in the powerpack under the supervision of the BMS 104. The control unit 108 continuously monitors the RPM value to ensure it reduces below or equals the predefined threshold. Engine braking is terminated once the RPM drops below the threshold or if the SOC reaches or exceeds the predefined level. Similarly, engine braking is disabled if the BMS 104 disallows charging. The system 100 ensures efficient energy recovery, controlled braking, and safe operation by dynamically managing engine braking based on real-time parameters.
In an embodiment, the system 100 comprises a motor 102, a battery management system (BMS) 104, a throttle demand sensing unit 106, and a control unit 108, which collectively enable engine braking in a gear-based EV. The motor 102 converts electrical energy into mechanical energy for propulsion and transitions into regenerative mode during engine braking to convert kinetic energy into electrical energy. The BMS 104 monitors the state of charge (SOC), charging current, and powerpack output to determine whether conditions allow energy recovery. The control unit 108 activates engine braking upon determining that the SOC is below a predefined threshold, the BMS 104 permits charging at the required current, and the motor RPM exceeds a predefined level. The configuration prevents overcharging while managing motor speed to avoid exceeding operational limits.
In an embodiment, the system 100 comprises a control unit 108 that disables engine braking when specific conditions are detected. If the SOC exceeds a predefined threshold, the BMS 104 disallows further charging, or the motor RPM falls below the predefined level, the control unit 108 deactivates engine braking. This prevents unnecessary braking actions, eliminates stress on the drivetrain, and optimizes braking energy recovery. The control unit 108 evaluates these conditions in real-time based on monitored data from the BMS 104 and motor 102, and braking is disengaged appropriately under safe parameters.
In an embodiment, the system 100 comprises a control unit 108 that disables throttle input during engine braking until specific conditions are met. When engine braking is activated, the throttle demand sensing unit 106 input is overridden to avoid conflicting acceleration commands. Throttle input is restored when the SOC exceeds the threshold, the BMS 104 stops charging due to safety constraints, or the motor RPM drops below the predefined level. The process prevents simultaneous throttle and braking inputs, allowing seamless deceleration and energy recovery during braking events.
In an embodiment, the system 100 comprises a control unit 108 that calibrates predefined thresholds for SOC, charging current, and RPM based on the selected driving mode. For instance, in an economy mode, thresholds for SOC and RPM are adjusted to maximize energy recovery, while in performance mode, thresholds are set higher to prioritize braking responsiveness and power output. The control unit 108 dynamically adapts these values to match driving conditions, enabling engine braking and regeneration to operate effectively under varying operational scenarios.
In an embodiment, the system 100 comprises a control unit 108 that enables continuous regeneration of high charging current during engine braking. The motor 102 transitions into a regenerative state to convert kinetic energy into electrical energy, which the powerpack stores under supervision by the BMS 104. The BMS 104 regulates charging current to remain within a predefined range, such as 15 to 20 amperes, to optimize energy recovery while preventing overcharging or thermal stress. Continuous regeneration maximizes the availability of stored energy for subsequent vehicle operations, supporting efficient deceleration and energy utilization.
In an embodiment, the method 200 monitors critical parameters through the BMS 104, including SOC, charging current, and powerpack output, to determine the conditions for engine braking. The motor 102 performs propulsion and transitions into regenerative braking mode when braking is activated. The throttle demand sensing unit 106 detects operator input, and the control unit 108 evaluates the motor RPM and other conditions. Engine braking is activated when the SOC is below the predefined threshold, the charging current is permitted by the BMS 104, and the RPM exceeds the predefined level, providing controlled and safe deceleration.
In an embodiment, the method 200 disables throttle input during engine braking until conditions such as SOC exceeding the threshold, charging being disallowed by the BMS 104, or motor RPM falling below the predefined level are detected. The control unit 108 dynamically manages the transition between throttle override and normal input to prioritize braking while maintaining operational safety and smooth vehicle operation.
In an embodiment, the method 200 calibrates predefined thresholds for SOC, charging current, and motor RPM based on the selected driving mode. The control unit 108 dynamically adjusts these parameters to align engine braking and regeneration with specific driving environments, such as urban or highway driving. The calibration customizes braking and energy recovery to meet the performance requirements of the selected mode.
In an embodiment, the method 200 enables continuous regeneration of high charging current during engine braking. The motor 102 generates electrical energy during deceleration, which is regulated by the BMS 104 and stored in the powerpack. The control unit 108 maintains charging current within a predefined high range to maximize energy recovery without exceeding safety limits, providing effective energy management throughout braking operations.
In the description of the present invention, it is also to be noted that, unless otherwise explicitly specified or limited, the terms “disposed,” “mounted,” and “connected” are to be construed broadly, and may for example be fixedly connected, detachably connected, or integrally connected, either mechanically or electrically. They may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Modifications to embodiments and combination of different embodiments of the present disclosure described in the foregoing are possible without departing from the scope of the present disclosure as defined by the accompanying claims. Expressions such as “comprising”, “comprising”, “incorporating”, “have”, “is” used to describe and claim the present disclosure are intended to be construed in a non- exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural where appropriate.
Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the present disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.
,CLAIMS:WE CLAIM:
1. A system 100 for enabling an engine braking in a gear-based electric vehicle (EV), comprising:
a motor 102 configured to drive the EV;
a battery management system (BMS) 104 monitors a state of charge (SOC), a charging current, and a current output of a powerpack;
a throttle demand sensing unit 106 senses a throttle input from an operator; and
a control unit 108:
determines a RPM value of the motor 102; and
enables the engine braking reduces the RPM value below a predefined level, wherein the engine braking is enabled upon determining each of the:
determined SOC of the powerpack is below than a predefined threshold;
BMS 104 allows charging of the powerpack at the charging current; and
detected RPM value exceeds the predefined level.
2. The system 100 as claimed in claim 1, wherein the control unit 108 disables the engine braking upon detecting at least one of the:
determined SOC of the powerpack exceeds the predefined threshold;
BMS 104 disallows charging of the powerpack at the charging current; and
detected RPM value is less than the predefined level.
3. The system 100 as claimed in claim 1, wherein the control unit 108 disables the throttle input during engine braking until detection of at least one of the:
determined SOC of the powerpack exceeds the predefined threshold;
BMS 104 disallows charging of the powerpack at the charging current; and
detected RPM value is less than the predefined level.
4. The system 100 as claimed in claim 1, wherein the control unit 108 calibrates the predefined threshold based on a selected driving mode.
5. The system 100 as claimed in claim 1, wherein the control unit 108 enables a continuous regeneration of the high charging current during the engine braking.
6. The system of claim 1, wherein the control unit 108 accesses a stored RPM value of the motor 102, wherein the stored RPM value is sensed, at a previous instance, and stored in a storage unit with an associated timestamp.
7. The system of claim 6, wherein the control unit 108 determines the RPM value of the motor 102 based on the last stored RPM value in the storage unit to avoid a delay due to data transmission through a Controller Area Network (CAN) bus.
8. A method 200 for enabling an engine braking in a gear-based electric vehicle (EV), comprising:
monitoring, through a battery management system (BMS) 104, a state of charge (SOC), a charging current, and a current output of a powerpack;
utilizing, a motor 102, to drive the EV;
sensing, through a throttle demand sensing unit 106, a throttle input from an operator;
determining, a RPM value of the motor 102; and
enabling, an engine braking by a control unit 108, wherein the enabling is performed upon determining the:
determined SOC of the powerpack is below than a predefined threshold;
BMS 104 allows charging of the powerpack at the charging current; and
detected RPM value exceeds a predefined level.
9. The method 200 as claimed in claim 8, wherein the control unit 108 disables the throttle input during the engine braking until detection of at least one of the:
determined SOC of the powerpack exceeds the predefined threshold;
BMS 104 disallows charging of the powerpack at the charging current; and
detected RPM value is less than the predefined level.
10. The method 200 as claimed in claim 8, wherein the control unit 108 calibrates the predefined threshold based on a selected driving mode.
11. The method 200 as claimed in claim 8, wherein the control unit 108 enables continuous regeneration of the high charging current during the engine braking.