Regenerative braking control device and method

Abstract

The present disclosure provides a regenerative braking control system and method configured to maximize vehicle energy efficiency by allowing an electric vehicle to vary a maximum regenerative braking allowance for regenerative braking control and brake force distribution in the electric vehicle. The method includes analyzing a driver vehicle speed pattern based on vehicle speed data of the vehicle to obtain energy efficiency information corresponding to a variation of the maximum regenerative braking allowance, determining the maximum regenerative braking allowance considering the driver vehicle speed pattern based on the obtained energy efficiency information corresponding to the variation of the maximum regenerative braking allowance, and updating a previous maximum regenerative braking allowance.

Description

Technical Field This disclosure relates to systems and methods for controlling regenerative braking of electric vehicles driven by motors. Background Technology As is well known, hybrid electric vehicles (HEV), battery electric vehicles (BEV), fuel cell electric vehicles (FCEV), and range-extended electric vehicles (EREV) are all electric vehicles, and are usually collectively referred to as electric vehicles (xEV).

[0003] The aforementioned vehicle is driven by an electric motor, meaning the driving force is provided by the electric motor. The battery is connected to the motor via an inverter for charging and discharging, and the motor is powered by the battery.

[0004] In such electric vehicles, regenerative braking can be performed by an electric motor. In other words, during braking or coasting, the vehicle's kinetic energy can be recovered as electrical energy to charge the battery by generating electricity from a motor connected to the drive wheels.

[0005] In regenerative braking, the vehicle's fuel economy (i.e., energy efficiency) can be improved because the battery is charged by the electrical energy generated by the motor. Therefore, regenerative braking is crucial for improving the efficiency and fuel economy of such electric vehicles.

[0006] In electric vehicles, in addition to regenerative braking, friction braking is also performed based on the driver's braking operation, just like in other vehicles. Therefore, regenerative braking and friction braking may be performed simultaneously during braking, thereby distributing braking force according to the braking operation.

[0007] In other words, when the target braking force (i.e. the braking force required by the driver) is calculated based on the braking signal corresponding to the driver's braking operation (driver's braking input) (e.g., the brake pedal position sensor (BPS) signal based on the brake pedal operation), regenerative braking force and friction braking force (hydraulic braking force) need to be allocated to meet the target braking force.

[0008] In addition, after determining the regenerative braking force and friction braking force applied to the wheels through braking force distribution, motor regenerative braking control and friction braking control are executed to generate the respective distributed braking forces.

[0009] In vehicles employing regenerative braking, the maximum permissible regenerative braking force refers to the maximum regenerative braking force achievable through regenerative braking, which can be expressed as deceleration (g). Since the regenerative braking force is limited by the maximum permissible regenerative braking force set by the vehicle when distributing regenerative and frictional braking forces, the regenerative and frictional braking forces of the vehicle may vary depending on the maximum permissible regenerative braking force.

[0010] For example, the greater the maximum allowable regenerative braking capacity set for a vehicle, the greater the regenerative braking force generated, which can reduce the frequency of friction braking and increase the amount of recyclable energy from the battery.

[0011] However, in existing technologies, the maximum regenerative braking allowance is set during the vehicle development phase and applied directly to the vehicle after mass production. Therefore, although each maximum regenerative braking allowance has its advantages and disadvantages, the maximum regenerative braking allowance cannot be changed at the factory. Consequently, the fixed maximum regenerative braking allowance at the time of manufacture must remain unchanged until the vehicle is scrapped.

[0012] The information contained in the background section is only intended to enhance the understanding of the background of this disclosure and may therefore contain information that is not prior art to a person skilled in the art in this country. Summary of the Invention This disclosure aims to address the aforementioned problems existing in the prior art. One aspect of this disclosure is to provide a regenerative braking control system and method configured to maximize vehicle energy efficiency by allowing an electric vehicle to change the maximum regenerative braking allowance used for braking force distribution and regenerative braking control.

[0014] The aspects of this disclosure are not limited to those described above, and other aspects not mentioned will be clearly understood by those skilled in the art from the following description.

[0015] In one aspect, this disclosure provides a regenerative braking control system, comprising: a vehicle speed sensor for detecting the vehicle speed; a controller for controlling the regenerative braking of the vehicle; a communication device for transmitting vehicle speed data detected by the vehicle speed sensor; and a computing device that analyzes the driver's vehicle speed pattern based on the vehicle speed data transmitted through the communication device to obtain energy efficiency information corresponding to changes in the maximum regenerative braking allowance, and is configured to determine, based on the energy efficiency information corresponding to changes in the maximum regenerative braking allowance, a maximum regenerative braking allowance considering the driver's vehicle speed pattern, and transmit the determination result to the vehicle, wherein the controller updates the maximum regenerative braking allowance used to control the regenerative braking of the vehicle to the maximum regenerative braking allowance received from the computing device.

[0016] In an exemplary embodiment of this disclosure, the computing device can find an energy efficiency saturation point where the energy efficiency converges to a specific value based on the energy efficiency information corresponding to the change in the maximum regenerative braking allowance, and is configured to determine the maximum regenerative braking allowance corresponding to the energy efficiency saturation point as the maximum regenerative braking allowance taking into account the driver's vehicle speed mode.

[0017] In another exemplary embodiment of this disclosure, the computing device may be a server located outside the vehicle, which is wirelessly connected to the vehicle via a communication device.

[0018] In yet another exemplary embodiment of this disclosure, the computing device may be wired to the vehicle via a communication device.

[0019] In another exemplary embodiment of this disclosure, the computing device can receive vehicle speed data from the vehicle during a specific sampling period within a predetermined time period, redetermine the maximum regenerative braking allowable amount taking into account the driver's vehicle speed mode based on the vehicle speed data within the predetermined time period, and transmit the redetermined maximum regenerative braking allowable amount to the vehicle.

[0020] In another exemplary embodiment of this disclosure, a predetermined time period may be set as an update cycle for the maximum regenerative braking allowance in the computing device, and the computing device may repeat the following process: determining the maximum regenerative braking allowance taking into account the driver's speed pattern based on vehicle speed data received from the vehicle during the update cycle, and transmitting the re-determined maximum regenerative braking allowance to the vehicle during the update cycle.

[0021] In another exemplary embodiment of this disclosure, the computing device may be configured to determine the total energy consumption of the acceleration phase and the constant speed driving phase based on vehicle speed data within a predetermined time period, and the total recovered energy of different maximum regenerative braking allowances during the deceleration phase, and to use information on the total energy consumption, the total recovered energy, and the total driving distance determined based on the vehicle speed data within the predetermined time period to determine energy efficiency information corresponding to the change in the maximum regenerative braking allowance.

[0022] In another exemplary embodiment of this disclosure, the computing device may be configured to determine instantaneous energy consumption based on vehicle speed, vehicle driving resistance, and vehicle weight data at the previous and next sampling times during acceleration and constant speed driving, and may be configured to determine total energy consumption by adding the instantaneous energy consumption over a predetermined time period.

[0023] In another exemplary embodiment of this disclosure, the computing device may be configured to determine instantaneous recovered energy from vehicle speed at the previous sampling time and the next sampling time during deceleration, deceleration obtained from the vehicle speed data, vehicle driving resistance and vehicle weight data, and may be configured to determine total recovered energy by adding the instantaneous recovered energy over a predetermined time period.

[0024] In another exemplary embodiment of this disclosure, when determining instantaneous regenerative braking energy, the computing device may change the maximum regenerative braking allowance and may be configured to determine the instantaneous regenerative braking energy corresponding to each maximum regenerative braking allowance using regenerative braking with the changed maximum regenerative braking allowance; may determine the instantaneous regenerative braking energy of each maximum regenerative braking allowance using deceleration based on determining that the deceleration is equal to or less than the changed maximum regenerative braking allowance; may determine the instantaneous regenerative braking energy of each maximum regenerative braking allowance using the maximum regenerative braking allowance instead of deceleration based on determining that the deceleration is greater than the changed maximum regenerative braking allowance; and may be configured to determine the total regenerative braking energy corresponding to each maximum regenerative braking allowance by adding the instantaneous regenerative braking energy determined using deceleration and the instantaneous regenerative braking energy determined using the maximum regenerative braking allowance within a predetermined time period.

[0025] In yet another exemplary embodiment of this disclosure, the system may further include an input device that operates in response to driver input to reset the updated maximum regenerative braking allowance to a preset initial value.

[0026] In another aspect, this disclosure provides a regenerative braking control method, comprising: transmitting vehicle speed data detected by a vehicle speed sensor via a communication device; obtaining energy efficiency information corresponding to changes in the maximum regenerative braking allowable amount based on the vehicle speed data transmitted from the vehicle via a computing device connected to the vehicle via the communication device; determining a maximum regenerative braking allowable amount considering the driver's vehicle speed mode by the computing device based on the energy efficiency information corresponding to the changes in the maximum regenerative braking allowable amount, and transmitting the determined maximum regenerative braking allowable amount to the vehicle; and updating the maximum regenerative braking allowable amount for controlling the vehicle's regenerative braking to the maximum regenerative braking allowable amount received from the computing device by a controller installed in the vehicle.

[0027] In an exemplary embodiment of this disclosure, the method may further include controlling the regenerative braking of the vehicle by a controller using an updated maximum regenerative braking allowance.

[0028] In another exemplary embodiment of this disclosure, when determining the maximum regenerative braking allowable amount considering the driver's vehicle speed mode, the computing device can find the energy efficiency saturation point where the energy efficiency converges to a specific value based on the energy efficiency information corresponding to the change in the maximum regenerative braking allowable amount, and can be configured to determine the maximum regenerative braking allowable amount corresponding to the energy efficiency saturation point as the maximum regenerative braking allowable amount considering the driver's vehicle speed mode.

[0029] Other aspects and exemplary implementations will be discussed below. Attached Figure Description The above and other features of this disclosure will now be described in detail with reference to the accompanying drawings, which are provided by way of example only and therefore do not limit this disclosure, wherein: Figure 1 This is a schematic diagram illustrating the relationship between the maximum allowable regenerative braking and the braking force distribution in a typical electric vehicle. Figure 2 This is a schematic diagram illustrating the configuration of a regenerative braking control system according to an exemplary embodiment of the present disclosure; Figure 3 This is a schematic diagram illustrating the state of performing an OTA update on a vehicle according to an exemplary embodiment of this disclosure; Figure 4 , Figure 5 and Figure 6 This is a schematic diagram illustrating the results of statistical analysis of deceleration based on the driver's driving mode and the trend of energy efficiency variation under different maximum regenerative braking allowable amounts, according to an exemplary embodiment of this disclosure. Figure 7 This is a flowchart illustrating the process of updating the maximum regenerative braking allowable amount in a regenerative braking control method according to an exemplary embodiment of this disclosure; and Figure 8 This is a schematic diagram showing energy efficiency curves corresponding to different maximum regenerative braking allowable amounts according to exemplary embodiments of the present disclosure.

[0031] It should be understood that the accompanying drawings are not necessarily drawn to scale, but rather present slightly simplified representations of various exemplary features illustrating the basic principles of this disclosure. Specific design features of this disclosure included herein, including, for example, specific dimensions, orientations, positions, and shapes, will be determined in part by the particular intended application and environment of use.

[0032] Throughout the accompanying drawings, reference numerals refer to the same or equivalent portions of this disclosure. Detailed Implementation The exemplary embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. The specific structural or functional descriptions presented in the exemplary embodiments of this disclosure are for illustrative purposes only, and the embodiments based on the concept of this disclosure can be implemented in various forms and should not be construed as limited to the exemplary embodiments described herein. Furthermore, since the concept of this disclosure can be modified in various ways and has various forms, the exemplary embodiments should not be construed as limiting the scope of this disclosure, but should be understood to include all modifications, equivalents, or substitutions falling within the concept and technical scope of this disclosure.

[0034] It should be understood that although the terms "first," "second," etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element may be referred to as a second element without departing from the scope of exemplary embodiments of this disclosure, and similarly, a second element may be referred to as a first element.

[0035] Furthermore, it should be understood that when an element is referred to as "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or indirectly connected or coupled to the other element through an intermediate element. Conversely, when an element is referred to as "directly connected" or "directly coupled" to another element, it means that there is no intermediate element. Other expressions describing the relationship between elements (e.g., "between" and "directly between," "adjacent" and "directly adjacent," etc.) should be interpreted similarly.

[0036] Where possible, the same reference numerals in the accompanying drawings will be used to refer to the same or similar parts. The terminology used herein is for descriptive purposes only and is not intended to limit the exemplary embodiments of this disclosure. As used herein, the singular forms “a” and “an” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the terms “comprising,” “including,” and “having” as used herein specify the presence of the stated components, steps, operations, and / or elements, but do not exclude the presence or addition of one or more other components, steps, operations, and / or elements.

[0037] Before describing the embodiments of this disclosure, the problems of the prior art will be described.

[0038] Figure 1 This is a schematic diagram showing the state in an electric vehicle with the maximum regenerative braking allowable amount set. The maximum regenerative braking allowable amount ([g]) and the braking force distribution state are shown in a coordinate system where the horizontal axis represents the brake pedal displacement value (brake pedal position sensor (BPS) value) and the vertical axis represents the braking force.

[0039] The braking force line "L" represents the total braking force, which can be the braking force required by the driver based on the brake pedal position sensor (BPS) value. Here, the braking force at point P is the maximum allowable regenerative braking amount. With the maximum allowable regenerative braking amount set, even if the brake pedal position sensor value is greater than or equal to point P, the regenerative braking force is limited to the maximum allowable regenerative braking amount.

[0040] In this situation, the insufficient portion of the total braking force is supplemented by friction braking force. Here, friction braking force (“Friction brake”) is divided into front axle applied to the front wheel side and rear axle applied to the rear wheel side.

[0041] As mentioned above, the maximum regenerative braking force in a vehicle is set as the maximum regenerative braking allowable amount. The larger the maximum regenerative braking allowable amount, the greater the regenerative braking force, which has the advantage of improving the vehicle's energy efficiency (fuel economy).

[0042] Furthermore, as the regenerative braking force increases, the frictional braking force decreases, thus solving the problem caused by the heat capacity of the brake disc and reducing dust caused by friction between the friction pads and the brake disc.

[0043] On the other hand, the larger the maximum allowable regenerative braking force, the greater the regenerative braking force, thus reducing the durability of components such as the motor shaft and bearings in the PE system. Furthermore, due to reduced use of friction braking, brake disc rusting increases, leading to increased noise and aesthetic deterioration.

[0044] In the existing technology, the maximum allowable regenerative braking amount is determined during the vehicle development stage, and this value is directly applied to mass-produced vehicles and is used as a fixed value after leaving the factory, providing drivers with a fixed regenerative braking experience.

[0045] The distribution of deceleration will vary depending on the driver's driving habits or vehicle characteristics. If the maximum allowable regenerative braking amount that was pre-set during the vehicle development stage is still used for mass-produced vehicles, different vehicles will exhibit different advantages and disadvantages.

[0046] For example, the preset maximum regenerative braking allowance may be too high for different vehicles, which could lead to brake disc rust or deterioration of the PE system's durability. On the other hand, the preset maximum regenerative braking allowance may be too low for different vehicles, which could be detrimental in terms of energy efficiency.

[0047] As mentioned above, in the prior art, the maximum allowable regenerative braking may be too large or too small depending on the vehicle or driver, leading to various problems. However, the maximum allowable regenerative braking cannot be changed in mass-produced and factory-delivered vehicles. Furthermore, it is difficult for drivers to find the optimal value of the maximum allowable regenerative braking for their vehicle.

[0048] Furthermore, the maximum regenerative braking allowance preset during the vehicle development phase is too small relative to the driving modes of drivers after mass production and delivery, so the actual energy efficiency of the vehicle cannot be maximized. In this case, it is impossible to check the results and change the maximum regenerative braking allowance.

[0049] Therefore, in order to solve the above problems, this disclosure provides a system and method for determining the optimal maximum regenerative braking allowance based on the driver's driving experience during vehicle operation, and applying the optimal maximum regenerative braking allowance to the vehicle, rather than using a fixed value set during the vehicle development phase.

[0050] Unlike existing technologies that apply fixed initial values ​​set before mass production to vehicles leaving the factory, according to an exemplary embodiment of this disclosure, the optimal maximum allowable regenerative braking amount is determined based on information indicating the vehicle's driving state (i.e., vehicle driving information), taking into account the actual driver's driving tendencies and driving patterns, and the determination result is applied to the vehicle for regenerative braking control.

[0051] In an exemplary embodiment of this disclosure, if the driver's driving tendencies or driving patterns change during recent vehicle operation, or if the driver is changed to another driver, a new maximum allowable amount of regenerative braking can be determined based on vehicle driving information within a predetermined time period after the change.

[0052] Furthermore, the maximum regenerative braking allowance is changed to a newly determined maximum regenerative braking allowance through the update process described below. Therefore, the modified maximum regenerative braking allowance is used to control the vehicle's regenerative braking.

[0053] Figure 2 This is a schematic diagram illustrating the configuration of a regenerative braking control system according to an exemplary embodiment of the present disclosure. Figure 3 This is a schematic diagram illustrating the state of a vehicle performing an over-the-air (OTA) update according to an exemplary embodiment of this disclosure.

[0054] like Figure 2 and Figure 3 As shown, the regenerative braking control system according to an exemplary embodiment of the present disclosure includes a vehicle speed sensor 11, a controller 13 and a communication device 14 disposed in the vehicle 10, and a computing device 20 external to the vehicle.

[0055] The computing device 20 is a device for transmitting or receiving information with the vehicle 10 wirelessly or via a wired connection, and allows the communication device 14 to interconnect the computing device 20 and the controller 13 for wireless or wired communication.

[0056] In the case of using wireless communication, the computing device can be a server 20 located outside the vehicle. In the following description, the computing device 20 will be described as an example of a server 20 that communicates wirelessly with the controller 13 via the communication device 14 of the vehicle 10.

[0057] In an exemplary embodiment of this disclosure, a server 20 outside the vehicle is configured to determine a new maximum regenerative braking allowance based on vehicle speed data transmitted from the vehicle 10 over a specific time period, taking into account the actual driver's driving tendencies and patterns.

[0058] Here, server 20 analyzes the driver's vehicle speed pattern based on vehicle speed data to determine the energy efficiency corresponding to the change in the maximum regenerative braking allowance, and determines the maximum regenerative braking allowance taking into account the driver's vehicle speed pattern based on the energy efficiency information corresponding to the change in the determined maximum regenerative braking allowance.

[0059] Server 20 transmits the new maximum regenerative braking allowance to vehicle 10, and then vehicle 10 receives the new maximum regenerative braking allowance transmitted from server 20 via communication device 14.

[0060] Accordingly, the controller 13 of vehicle 10 updates the maximum regenerative braking allowance from the existing value to the new maximum regenerative braking allowance received via communication device 14, and then, accordingly, the controller 13 of vehicle 10 is configured to control the regenerative braking of the vehicle using the updated new maximum regenerative braking allowance.

[0061] In an exemplary embodiment of this disclosure, the server 20 outside the vehicle may be a telematics system server that provides telematics services via a network, or a cloud server configured to store data via the Internet, run applications, and perform tasks in a virtualized environment.

[0062] In an exemplary embodiment of this disclosure, the specific time period can be a preset cycle, and can be a preset OTA cycle between vehicle 10 and the server. As is well known, over-the-air (OTA) updates refer to a technology that allows software to be updated in real time via wireless communication technology.

[0063] In recent years, vehicles can update their software via OTA (Over-The-Air) without the need for appointments or USB connections, enabling the addition of new features, functional improvements, and fault repairs.

[0064] In an exemplary embodiment of this disclosure, a specific OTA update cycle can be set to update only the maximum regenerative braking allowance, and the maximum regenerative braking allowance of the controller 13 in the vehicle can be updated to the latest value using OTA.

[0065] Alternatively, the maximum regenerative braking allowance can be transferred to vehicle 10 for updating during the OTA update of other software between server 20 and vehicle 10.

[0066] In an exemplary embodiment of this disclosure, the update of the maximum regenerative braking allowance may be performed periodically at a preset period (e.g., 1 month) or may be performed irregularly.

[0067] In both cases, server 20 uses data such as vehicle speed of vehicle 10 collected from the last update to the next update (or before the next update) to redetermine the maximum regenerative braking allowance, and transmits the redetermined maximum regenerative braking allowance to vehicle 10 in the next update.

[0068] In this way, server 20 uses data from the time period immediately following the previous update (update cycle) to determine the maximum regenerative braking allowance, and then transmits the latest maximum regenerative braking allowance to vehicle 10 at a transmission time based on a specific cycle or at a transmission time determined on demand, thereby updating the maximum regenerative braking allowance to the latest transmitted value. Therefore, when controller 13 of vehicle 10 performs regenerative braking control, including the brake force distribution process, the updated maximum regenerative braking allowance can be used.

[0069] Vehicle speed sensor 11 is a sensor configured to detect vehicle speed information required to update the maximum regenerative braking allowance; wheel speed sensors can be used as such vehicle speed sensors. Additionally, vehicle driving information received by server 20 from vehicle 10 may include vehicle speed.

[0070] In other words, the vehicle speed can be transmitted from vehicle 10 to server 20, and the vehicle speed detected by vehicle speed sensor 11 in vehicle 10 can be transmitted to server 20 through communication device 14. Here, the controller 13 of vehicle 10 can receive the signal from vehicle speed sensor 11 through the vehicle network to obtain vehicle speed information and transmit the result to server 20 in real time.

[0071] In addition, vehicle 10 wirelessly transmits vehicle speed information to server 20 according to a preset sampling period (sampling rate). Server 20 receives and stores the vehicle speed data received from vehicle 10 within the time period immediately following the last update, and then uses the stored vehicle speed data to redetermine the maximum allowable regenerative braking amount.

[0072] In this way, server 20 is configured to use vehicle speed data collected by vehicle 10 in the time period immediately following the last update to determine the maximum allowable regenerative braking amount, and then transmit the result to the vehicle.

[0073] Here, server 20 analyzes the vehicle speed pattern of vehicle 10 considering the driver's driving experience during the above time period to determine the energy efficiency (γ) corresponding to different (each) maximum regenerative braking allowances, and analyzes the changes in energy efficiency of different maximum regenerative braking allowances to determine the final maximum regenerative braking allowance.

[0074] More specifically, server 20 is configured to determine the regenerative energy of the deceleration phase by changing the maximum regenerative braking allowance based on vehicle speed data collected from vehicle 10 in the time period immediately following the last update, use the determined regenerative energy and the electrical energy consumption during vehicle operation to obtain energy efficiency information defined as a function of the maximum regenerative braking allowance, and then be configured to determine the maximum regenerative braking allowance when the energy efficiency in the aforementioned time period converges to any value from the obtained energy efficiency information as the vehicle's final maximum regenerative braking allowance.

[0075] Energy efficiency information is defined as a function of the maximum regenerative braking allowable amount, that is, the energy efficiency corresponding to the maximum regenerative braking allowable amount. It is an estimated energy efficiency, which can take into account the driver's driving mode and vehicle speed mode.

[0076] Therefore, the final maximum regenerative braking allowance obtained by analyzing the estimated energy efficiency of different maximum regenerative braking allowances is based on the maximum regenerative braking allowance at vehicle speed that takes into account the driver's driving experience.

[0077] The aforementioned time period can be the period immediately following the last update to the next update (corresponding to the update cycle), and the recovered energy and electrical energy consumption correspond to the total energy within this time period. Furthermore, electrical energy consumption refers to the electrical energy consumed by the vehicle during acceleration and constant-speed driving.

[0078] The regenerative braking control system according to an exemplary embodiment may further include an input device 12 for resetting the updated maximum regenerative braking allowance in the vehicle 10 to the value at the time the vehicle was manufactured.

[0079] When a vehicle driver (whose maximum regenerative braking allowance has been updated based on that driver during the vehicle's use) is replaced by a new driver (e.g., through a used car transaction), the vehicle's maximum regenerative braking allowance is in a personalized state based on the previous driver.

[0080] In other words, the vehicle is already configured with a maximum regenerative braking allowance tailored to the previous driver's driving style (including speed mode, etc.). Therefore, the previous driver's maximum regenerative braking allowance may not be suitable for the new driver's driving style. As a result, problems such as reduced energy efficiency, deterioration of PE system durability, and rust may reappear.

[0081] Therefore, in the event of a change of vehicle driver, an input device 12 is provided so that the new driver can reset the previously updated maximum regenerative braking allowance to the value set at the time the vehicle was manufactured.

[0082] The input device 12 is connected to the controller 13, so that the controller 13 can recognize the operating status of the input device 12. The input device can be an input device such as a button or switch installed in the vehicle, an input device of an audio-visual navigation (AVN) system, a touch screen, etc.

[0083] When a new driver resets the input device 12, the controller 13 will change the updated and stored maximum regenerative braking allowance to the initial value when the vehicle was manufactured.

[0084] Therefore, before the next update arrives, server 20 collects the new driver's speed data from vehicle 10, analyzes the speed pattern taking into account the new driver's driving experience, determines the new maximum regenerative braking allowance, and transmits the results to vehicle 10 to update the existing maximum regenerative braking allowance to the new value.

[0085] Furthermore, the server 20 repeats the above update process through communication with the vehicle 10, so that the maximum regenerative braking allowance suitable for the new driver can be reset in the controller 13 of the vehicle 10, and the updated latest value can be used to control the regenerative braking of the vehicle.

[0086] During regenerative braking, if the driver's required braking force is equal to or less than the updated maximum regenerative braking allowance, the required braking force can be met by regenerative braking alone. However, if the driver's required braking force exceeds the maximum regenerative braking allowance, brake force distribution is applied because the regenerative braking force is limited to the maximum regenerative braking allowance (see...). Figure 1 This allows the driver to distribute the required braking force as the maximum allowable regenerative braking amount and friction braking force.

[0087] Figures 4 to 6 This is a schematic diagram illustrating the results of statistical analysis of deceleration based on the driver's driving mode and the trend of energy efficiency variation under different maximum regenerative braking allowables according to an exemplary embodiment of this disclosure. Figure 4 The data shows the frequency of deceleration usage for a specific driver, with deceleration below approximately 0.2g being used very frequently and deceleration above 0.3g being used very infrequently. Figure 5 This indicates that the primary braking range for a specific driver is less than or equal to 0.2g. Figure 6 This shows that the energy efficiency converges to a specific value starting from a deceleration of 0.2g or higher.

[0088] According to an exemplary implementation, the vehicle speed pattern, taking into account the driver's driving experience, is analyzed during the time period between the previous update and the next update to determine the estimated energy efficiency under different maximum regenerative braking allowances, and to determine, as... Figure 6The energy efficiency shown converges to a specific energy efficiency saturation point, and then the maximum regenerative braking allowable amount corresponding to the above energy efficiency saturation point is determined as a new value.

[0089] Therefore, the vehicle's maximum regenerative braking allowance is updated to a new value, enabling customized regenerative braking control for the vehicle / driver. Thus, continuous updates can maximize energy efficiency and improve the aforementioned issues.

[0090] Figure 7 This is a flowchart illustrating the process of updating the maximum regenerative braking allowable amount in a regenerative braking control method according to an exemplary embodiment of the present disclosure, and illustrating the process of performing the first OTA update while the initial value of the maximum regenerative braking allowable amount at the time of vehicle manufacture is stored in the vehicle.

[0091] exist Figure 7 In the middle, "d old "[g]" represents the initial value of the maximum regenerative braking allowance when the vehicle leaves the factory. In the exemplary embodiments of this disclosure, it is also defined as the current maximum regenerative braking allowance based on the last update, including the initial value of the maximum regenerative braking allowance.

[0092] In exemplary embodiments of this disclosure, such as Figure 7 As shown, after the first OTA update is performed, OTA updates can be performed continuously in the same way, and by repeating OTA updates, the maximum regenerative braking allowance can be reset to a value that takes into account the driver's driving mode.

[0093] The regenerative braking control method according to an exemplary embodiment includes a process of updating the maximum permissible regenerative braking amount of the vehicle. Furthermore, the regenerative braking control method according to an exemplary embodiment of this disclosure may also include a process of performing regenerative braking of the vehicle using the updated maximum permissible regenerative braking amount. Figure 7 As shown, the vehicle stores the maximum regenerative braking allowable amount when the vehicle leaves the factory (S11). Subsequently, during the vehicle's operation, the server 20 derives the energy efficiency curves corresponding to different maximum regenerative braking allowable amounts based on the vehicle's speed data (S12).

[0094] Therefore, the controller 13 acquires vehicle speed information from the signal of the vehicle speed sensor 110 and transmits the acquired vehicle speed information from the vehicle 10 to the server 20. Here, the vehicle speed data acquired in the vehicle 10 according to a preset sampling period can be transmitted to the server 20 in real time.

[0095] Server 20 uses vehicle speed data received from vehicle 10 to determine the energy efficiency curve for the maximum allowable regenerative braking. The process of deriving the curve representing the energy efficiency for the maximum allowable regenerative braking is as follows.

[0096] First, server 20 is configured to use vehicle speed data to determine the energy consumption during vehicle operation. Here, the energy consumption during acceleration and constant speed driving is measured at the previous sampling time (t). i-1 ) and the next (which could be the current) sampling time (t) i Energy consumption between ) (E) acc_i It can be determined by the following equation 1.

[0097] Equation 1 Here, f0, f1, and f2 represent the vehicle's driving resistance, values ​​corresponding to the vehicle type, and can be pre-stored in server 20. Alternatively, the driving resistance can be transmitted from the vehicle along with its speed. Furthermore, v i-1 Represents the previous sampling time (t) i-1 The speed of the vehicle, v i Indicates the next (or current) sampling time (t) i The speed of the vehicle is M, and the weight of the vehicle is M.

[0098] The vehicle weight can be a value pre-stored in server 20 for each vehicle type, or it can be transmitted from vehicle 10 along with vehicle speed. Since vehicle weight depends on the number of passengers, cargo, etc., the actual weight value estimated in real time by controller 13 based on vehicle driving information through weight estimation logic can be used and transmitted to server 20 to determine energy consumption.

[0099] In exemplary embodiments of this disclosure, various known methods for estimating vehicle weight in real time based on information collected from the vehicle can be used. Detailed descriptions of known vehicle weight estimation methods will be omitted.

[0100] In Equation 1, a i This represents the previous sampling time (t) during acceleration and constant speed travel. i-1 ) and the next (which could be the current) sampling time (t) i The vehicle acceleration between () can be the derivative of the vehicle speed. Furthermore, s i Represents the previous sampling time (t) i-1 ) and the next (which could be the current) sampling time (t) i The distance traveled between vehicles can be the integral of their speeds.

[0101] The energy consumption (E) determined by Equation 1 acc_i ) represents the instantaneous energy consumption during the sampling period, over the entire time period (t). end and t start Energy consumption during the time period between (the two periods) can be determined by Equation 2.

[0102] Equation 2 Among them, E total_cycle This represents the total energy consumption during the update cycle (i.e., the time period immediately between the previous update and the next update). As shown in Equation 2, the total energy consumption (E) during the entire time period... total_cycle This can be achieved by considering the instantaneous energy consumption (E) determined by Equation 1. acc_i The result is obtained by adding them together.

[0103] In equation 2, t start This indicates the point immediately following the last update where energy efficiency is determined. Additionally, t end This indicates the moment when energy efficiency is last determined before the next update. In the case of the first update of the maximum regenerative braking allowance after the vehicle leaves the factory, t... start It could be the time the vehicle was manufactured.

[0104] Therefore, server 20 is configured to determine the previous sampling time (t) within the same deceleration time period. i-1 ) and the next sampling time (t) i Energy recovery between ) (E acc_i It can be determined by the following equations 3 and 4.

[0105] Equation 3 Equation 4 In equations 3 and 4, d i Indicates the previous sampling time (t) during deceleration. i-1 ) and the next sampling time (t) i The actual vehicle deceleration between ( ) can be a derivative of the vehicle speed.

[0106] In an exemplary embodiment of this disclosure, the acceleration, constant speed, and deceleration of the vehicle can be determined in real time by the server 20 from the vehicle speed data received from the vehicle 10.

[0107] Generally, the values ​​of deceleration and acceleration have opposite signs. That is, when the acceleration value of a vehicle is defined as a positive (+) value, the deceleration value is defined as a negative (-) value.

[0108] However, in Equations 3 and 4, the actual vehicle deceleration (d) i The value is defined as a positive (+) value, and the actual vehicle deceleration d i It can be defined as the absolute value of the actual vehicle deceleration.

[0109] In addition, d limit This represents the maximum permissible regenerative braking amount, which can be compared with the actual vehicle deceleration value d in Equations 3 and 4. i It is defined as a positive (+) value. Furthermore, in Equations 3 and 4, the units for actual vehicle deceleration and maximum permissible regenerative braking can be expressed in g (gravitational acceleration).

[0110] In an exemplary embodiment of this disclosure, server 20 is configured to determine the recovered energy under different maximum regenerative braking allowances using equations 3 and 4, while simultaneously changing the maximum regenerative braking allowance at certain intervals. Here, the changed maximum regenerative braking allowance may be as described below. Figure 8 The coordinate values ​​on the horizontal axis of the energy efficiency curve shown.

[0111] As shown in Equation 3, at the absolute value of the actual vehicle deceleration (d) i ) less than or equal to the maximum allowable regenerative braking amount (d) limit (d) i ≤ d limit In the case of determining the recoverable energy (E) reg_i When using Equation 3, and the absolute value of the actual vehicle deceleration (d) i () is used as a deceleration value.

[0112] On the other hand, in the absolute value of the actual vehicle deceleration (d) i ) greater than the maximum allowable regenerative braking amount (d) i >d limit In the case of regenerative braking, only according to the maximum regenerative braking allowable amount (d) limit Energy is recovered by limiting the deceleration (deceleration is limited to the maximum allowable regenerative braking). In this case, the recovered energy (E) is determined. reg_i When using Equation 4, and the maximum allowable regenerative braking amount (d) limit () is used as a deceleration value.

[0113] The recovered energy (E) determined by equations 3 and 4 reg_i ) represents the instantaneous energy consumption during the sampling period, and the entire time period (t) of the update cycle. end and t start Energy recovered during the time period between (E) regen_Cycle It can be determined by Equation 5.

[0114] Equation 5 Among them, E regen_Cycle Represents energy consumption (E)total_cycle The energy recovered during the deceleration phase within the same time period, and can also be the total energy recovered during the update cycle (i.e., the time between the previous update and the next update).

[0115] As shown in Equation 5, the total energy consumption (E) over the entire time period regen_Cycle Energy (E) can be recovered instantaneously by means of the energy determined by equations 3 and 4. reg_i The result is obtained by adding them together.

[0116] In determining the total recovered energy, the instantaneous recovered energy for different maximum regenerative braking allowances is obtained through Equations 3 and 4, and the total recovered energy for different maximum regenerative braking allowances can be obtained through Equation 5.

[0117] As mentioned above, in obtaining the recovered energy (E) over the entire time period total_cycle ) and energy consumption (E regen_Cycle After that, the energy efficiency (γ) of different maximum regenerative braking allowable amounts can be obtained through Equation 6.

[0118] Equation 6 As can be seen from Equation 6, the energy efficiency (γ) can be determined as total driving distance / (total energy consumption + total recovered energy), which can be obtained by a function with the maximum regenerative braking allowance as the variable. Figure 8 The energy efficiency curve shown can be derived from the energy efficiency obtained as a function of the maximum regenerative braking allowance.

[0119] In Equation 6, the total distance traveled is the total time interval (t). end and t start The instantaneous distance traveled by the vehicle (in seconds) within the time period between the two points is obtained based on the vehicle speed data. i The sum of ).

[0120] As described above, in the exemplary embodiments of this disclosure, energy efficiency is determined solely based on vehicle speed mode, unaffected by air conditioning load, electric field load, etc. In other words, vehicle speed-based energy efficiency is determined without considering air conditioning load and electric field load. The impact of regenerative braking is difficult to estimate using the instantaneous energy efficiency displayed on the vehicle's dashboard.

[0121] After determining the energy efficiency curves for different maximum regenerative braking allowable amounts, as follows: Figure 7 As shown, the energy efficiency saturation point is found from the determined energy efficiency information, and the maximum regenerative braking allowable amount corresponding to the energy efficiency saturation point is determined. Accordingly, the determined maximum regenerative braking allowable amount is set as the new maximum regenerative braking allowable amount (d). new ).

[0122] Figure 8 This is a schematic diagram illustrating the energy efficiency based on the maximum regenerative braking allowance according to an exemplary embodiment of the present disclosure, and shows energy efficiency curves for different maximum regenerative braking allowances. Here, the horizontal axis represents the maximum regenerative braking allowance ([g]), and the vertical axis represents the energy efficiency ([km / kWh]).

[0123] Given the energy efficiency curves for different maximum regenerative braking allowables as described above, determine the energy efficiency saturation point where the energy efficiency converges to a specific value, and define the maximum regenerative braking allowable corresponding to the energy efficiency saturation point as the newly updated maximum regenerative braking allowable (d). new (S13).

[0124] As the maximum allowable regenerative braking capacity increases, energy efficiency also improves. (Refer to...) Figure 8 The larger the maximum allowable regenerative braking in the energy efficiency curve, the greater the corresponding increase in energy efficiency.

[0125] Furthermore, as the maximum allowable regenerative braking increases, the energy efficiency converges to a specific value. The point where the energy efficiency converges to this specific value in the graph is defined as the energy efficiency saturation point, where the instantaneous rate of change of the portion of the graph where the energy efficiency no longer changes will be zero.

[0126] refer to Figure 8 As the maximum allowable regenerative braking increases, it can be seen that the instantaneous rate of change (rate of change of energy efficiency) at the point representing the corresponding energy efficiency in the curve gradually decreases.

[0127] In an exemplary embodiment of this disclosure, during the search for the energy efficiency saturation point, server 20 may be configured to change the instantaneous rate of change in the energy efficiency curve to a preset value ( The point is determined as the energy efficiency saturation point.

[0128] Here, the preset value can be set to a very small value close to 0, which can be determined taking into account the allowable range of energy efficiency or range (AER) for each vehicle type.

[0129] With the energy efficiency saturation point on the graph set as described above, the maximum regenerative braking allowable amount corresponding to the energy efficiency saturation point can be determined as the new maximum regenerative braking allowable amount (d). new The determined value corresponds to the maximum allowable regenerative braking amount for maximizing energy efficiency.

[0130] Therefore, as Figure 7 As shown, server 20 will determine the newly determined maximum regenerative braking allowable amount (d) new ) and the current maximum allowable amount of regenerative braking (d) oldThe values ​​are compared (S14), and if the difference between the two values ​​is close to or equal to the set value, no OTA update is performed, and the vehicle's existing maximum regenerative braking allowance is maintained (S16).

[0131] On the other hand, the newly determined maximum regenerative braking allowance (d) new ) and the current maximum regenerative braking allowance (d old In different cases, server 20 transmits the new maximum regenerative braking allowance to vehicle 10 and is configured to perform an OTA update to replace the existing value with the new value (S15).

[0132] Here, the new maximum regenerative braking allowable amount (d) new ) and the current maximum regenerative braking allowance (d old If the difference between the two values ​​is greater than a set value, server 20 can be configured to determine that the two values ​​are different.

[0133] The regenerative braking control system and method according to exemplary embodiments of the present disclosure have been described above, and the above-described regenerative braking control system and method can be applied to all vehicles that can be driven by an electric motor and regenerative braking, such as hybrid electric vehicles (HEV, PHEV), battery electric vehicles (BEV), fuel cell vehicles (FCEV) and range-extended electric vehicles (EREV).

[0134] The above describes the process by which an external server 20 determines the maximum allowable regenerative braking, wirelessly transmits the result to the vehicle 10, and updates the vehicle's maximum allowable regenerative braking. This method may only be applicable to vehicles that can be wirelessly updated using OTA (Over-The-Air) technology.

[0135] Here, for situations where wireless updates are not possible, this disclosure also provides a wired update scheme: the vehicle speed data since the last update is stored and accumulated in a memory, and then, when the computing device 20 is wired to the vehicle, the vehicle speed data is sent from the vehicle 10 to the computing device 20 via the communication device 14.

[0136] Therefore, the computing device 20 can use the vehicle speed data input from the vehicle 10 to redetermine the maximum regenerative braking allowance in the same manner as in the server 20.

[0137] Accordingly, the computing device 20 sends the new maximum regenerative braking allowance to the vehicle 10 via a wired connection to update the stored maximum regenerative braking allowance to the new value. Therefore, in the vehicle 10, regenerative braking control is performed using the new maximum regenerative braking allowance updated during driving.

[0138] Currently, for vehicles that cannot be updated wirelessly via OTA or similar methods, the maximum regenerative braking allowance can be updated via periodic wired updates.

[0139] According to the regenerative braking control system and method disclosed herein, by updating the maximum regenerative braking allowable amount used for brake force distribution and regenerative braking control to a value based on the driver's actual driving mode (vehicle speed mode), the vehicle's electrical efficiency can be maximized, and problems such as the degradation of the power electric (PE) system's durability or brake disc rusting can be solved.

[0140] The present disclosure has been described in detail above with reference to exemplary embodiments thereof. However, those skilled in the art will understand that changes may be made to these embodiments without departing from the principles and spirit of the present disclosure, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A regenerative braking control system, the system comprising: Vehicle speed sensor, configured to detect the vehicle speed; The controller is configured to control the vehicle's regenerative braking. A communication device configured to transmit vehicle speed data detected by the vehicle speed sensor; as well as The computing device is configured to analyze the driver's vehicle speed pattern based on vehicle speed data transmitted through the communication device in order to obtain energy efficiency information corresponding to the change in the maximum allowable amount of regenerative braking. The maximum regenerative braking allowance, taking into account the driver's vehicle speed mode, is determined based on the energy efficiency information corresponding to the change in the maximum regenerative braking allowance; and the determined result is transmitted to the vehicle. The controller updates the maximum regenerative braking allowance used to control the vehicle's regenerative braking to the maximum regenerative braking allowance received from the computing device.

2. The system according to claim 1, wherein, The computing device is configured to: find the energy efficiency saturation point where the energy efficiency converges to a specific value based on the energy efficiency information corresponding to the change in the maximum regenerative braking allowance, and determine the maximum regenerative braking allowance corresponding to the energy efficiency saturation point as the maximum regenerative braking allowance that takes into account the driver's vehicle speed mode.

3. The system according to claim 1, wherein, The computing device is a server configured outside the vehicle, and the server is wirelessly connected to the vehicle via the communication device.

4. The system according to claim 1, wherein, The computing device is wired to the vehicle via the communication device.

5. The system according to claim 1, wherein, The computing device is configured to: receive vehicle speed data from the vehicle at a specific sampling period during a predetermined time period, redetermine the maximum allowable regenerative braking amount considering the driver's vehicle speed mode based on the vehicle speed data within the predetermined time period, and transmit the newly determined maximum allowable regenerative braking amount to the vehicle.

6. The system according to claim 5, wherein, The predetermined time period is set as the update cycle for the maximum regenerative braking allowance in the computing device, and the computing device repeatedly performs the following process: determining the maximum regenerative braking allowance taking into account the driver's speed mode based on vehicle speed data received from the vehicle within the update cycle, and transmitting the newly determined maximum regenerative braking allowance to the vehicle in the update cycle.

7. The system according to claim 5, wherein, The computing device is configured to: determine the total energy consumption of the acceleration phase and the constant speed driving phase based on the vehicle speed data within the predetermined time period, as well as the total recovered energy of the deceleration phase corresponding to each maximum regenerative braking allowance; and determine the energy efficiency information corresponding to the change in the maximum regenerative braking allowance using the information of the total energy consumption, the total recovered energy, and the total driving distance determined based on the vehicle speed data within the predetermined time period.

8. The system according to claim 7, wherein, The computing device is configured to: determine instantaneous energy consumption based on vehicle speed, vehicle driving resistance, and vehicle weight data at the previous and subsequent sampling times during acceleration and constant speed driving, and determine the total energy consumption by adding the instantaneous energy consumption within the predetermined time period.

9. The system according to claim 7, wherein, The computing device is configured to: determine the instantaneous recovered energy based on the vehicle speed at the previous and next sampling times during deceleration, the deceleration obtained from the vehicle speed data, the vehicle driving resistance, and the vehicle weight data, and determine the total recovered energy by adding the instantaneous recovered energy within the predetermined time period.

10. The system according to claim 9, wherein, When determining the instantaneous recovered energy, the computing device is configured to: change the maximum regenerative braking allowance, and use the regenerative braking of the changed maximum regenerative braking allowance to determine the instantaneous recovered energy corresponding to each maximum regenerative braking allowance; Based on determining that the deceleration is equal to or less than the changed maximum regenerative braking allowance, the deceleration is used to determine the instantaneous recovered energy corresponding to each maximum regenerative braking allowance; Based on the determination that the deceleration is greater than the changed maximum regenerative braking allowance, the maximum regenerative braking allowance is used instead of the deceleration to determine the instantaneous recovered energy corresponding to each maximum regenerative braking allowance. The total recovered energy corresponding to each maximum regenerative braking allowance is determined by adding the instantaneous recovered energy determined by the deceleration within the predetermined time period and the instantaneous recovered energy determined by the maximum regenerative braking allowance within the predetermined time period.

11. The system according to claim 1, further comprising: The input device, in response to the driver's input, resets the updated maximum regenerative braking allowance to a preset initial value.

12. A regenerative braking control method, the method comprising the following steps: The vehicle speed data detected by the vehicle speed sensor is transmitted by the communication device; A computing device connected to the vehicle via the communication device obtains energy efficiency information corresponding to the maximum allowable change in regenerative braking based on vehicle speed data transmitted from the vehicle. The computing device determines the maximum regenerative braking allowance, taking into account the driver's vehicle speed mode, based on the energy efficiency information corresponding to the obtained maximum regenerative braking allowance change, and transmits the determined maximum regenerative braking allowance to the vehicle. The controller located within the vehicle updates the maximum regenerative braking allowance used to control the vehicle's regenerative braking to the maximum regenerative braking allowance received from the computing device.

13. The method of claim 12, further comprising the step of: The controller controls the regenerative braking of the vehicle using the updated maximum regenerative braking allowance.

14. The method according to claim 12, wherein, In the step of determining the maximum regenerative braking allowable amount taking into account the driver's vehicle speed mode, the computing device is configured to: find the energy efficiency saturation point where the energy efficiency converges to a specific value based on the energy efficiency information corresponding to the change in the maximum regenerative braking allowable amount, and determine the maximum regenerative braking allowable amount corresponding to the energy efficiency saturation point as the maximum regenerative braking allowable amount taking into account the driver's vehicle speed mode.

15. The method according to claim 12, wherein, The computing device is configured to: receive vehicle speed data from the vehicle at a specific sampling period during a predetermined time period, redetermine the maximum allowable regenerative braking amount considering the driver's vehicle speed mode based on the vehicle speed data within the predetermined time period, and transmit the newly determined maximum allowable regenerative braking amount to the vehicle.

16. The method according to claim 15, wherein, The predetermined time period is set as the update cycle for the maximum regenerative braking allowance in the computing device, and the computing device repeatedly performs the following process: determining the maximum regenerative braking allowance taking into account the driver's speed mode based on vehicle speed data received from the vehicle within the update cycle, and transmitting the newly determined maximum regenerative braking allowance to the vehicle in the update cycle.

17. The method according to claim 15, wherein, The computing device determines the total energy consumption of the acceleration and constant speed driving segments based on the vehicle speed data within the predetermined time period, as well as the total recovered energy of the deceleration segments corresponding to each maximum regenerative braking allowance; and uses the information of the total energy consumption, the total recovered energy, and the total driving distance determined based on the vehicle speed data within the predetermined time period to determine the energy efficiency information corresponding to the change in the maximum regenerative braking allowance.

18. The method according to claim 17, wherein, The computing device determines the instantaneous energy consumption based on the vehicle speed, vehicle driving resistance, and vehicle weight data at the previous and subsequent sampling times during acceleration and constant speed driving, and determines the total energy consumption by adding the instantaneous energy consumption within the predetermined time period.

19. The method of claim 17, wherein, The computing device determines the instantaneous recovered energy based on the vehicle speed at the previous and next sampling times during deceleration, the deceleration obtained from the vehicle speed data, the vehicle driving resistance, and the vehicle weight data, and determines the total recovered energy by adding the instantaneous recovered energy within the predetermined time period.

20. The method according to claim 19, wherein, When determining the instantaneous recovered energy, the computing device is configured to: change the maximum regenerative braking allowance, and use the regenerative braking of the changed maximum regenerative braking allowance to determine the instantaneous recovered energy corresponding to each maximum regenerative braking allowance; Based on determining that the deceleration is equal to or less than the changed maximum regenerative braking allowance, the deceleration is used to determine the instantaneous recovered energy corresponding to each maximum regenerative braking allowance; Based on the determination that the deceleration is greater than the changed maximum regenerative braking allowance, the maximum regenerative braking allowance is used instead of the deceleration to determine the instantaneous recovered energy corresponding to each maximum regenerative braking allowance. The total recovered energy corresponding to each maximum regenerative braking allowance is determined by adding the instantaneous recovered energy determined using the deceleration within the predetermined time period and the instantaneous recovered energy determined using the maximum regenerative braking allowance within the predetermined time period.

Images