Method of controlling uphill travel of a vehicle

Abstract

The present invention relates to a method of controlling uphill travel of a vehicle. A method of controlling uphill travel of a hybrid vehicle provided with a dual clutch transmission (DCT) can include determining, by a controller, a travel state of the vehicle based on information collected from the vehicle, performing, by the controller, high-torque control on an engine of the vehicle by increasing engine torque to control the engine at a predetermined high-torque engine operating point and reducing motor torque of a motor in the vehicle to meet a driver demand torque when the vehicle is determined to be in an uphill travel state, and comparing, by the controller, a state of charge (SOC) value of a battery with a set first SOC threshold value and performing engine and motor speed control to protect the SOC value of the battery when the SOC value of the battery is less than or equal to the first SOC threshold value during the performance of the high-torque control on the engine.

Description

Technical Field

[0001] This invention relates to a method for controlling the uphill driving of a vehicle. More specifically, this invention relates to a method for controlling the uphill driving of a vehicle, configured to always ensure a suitable state of charge (SOC) value of the battery by minimizing battery discharge during uphill driving, and configured to minimize energy consumption during acceleration. Background Technology

[0002] In recent years, the use of dual clutch transmissions (DCTs), which are configured to enable rapid gear shifting without power interruption, has been increasing in vehicles.

[0003] In a DCT, two input shafts that receive power intermittently via two clutches and two output shafts corresponding to the two input shafts form a separate transmission mechanism to alternately form a series of gears according to the gear ratio.

[0004] In this configuration, the dual-clutch transmission (DCT) is configured to allow power from the vehicle's drive source to be transmitted to one of the two input shafts, and the two input shafts, two output shafts, and two clutches are configured to enable shifting between odd and even gears in a series of gears.

[0005] Furthermore, the gear sequence and actual gear shifting are performed through torque switching, where one of the two clutches engages while the other disengages, thus preventing torque drop during gear shifting and enabling the gear shift to be completed.

[0006] In recent years, dual-clutch transmissions (DCTs) have also been installed in electrified vehicles such as hybrid electric vehicles (HEVs) and plug-in hybrid electric vehicles (PHEVs), and the application of DCTs is gradually expanding in order to improve the fuel efficiency of electrified vehicles and provide drivers with more driving pleasure.

[0007] In the case of HEVs and PHEVs equipped with DCT, there is a high degree of control freedom because there are two clutches in addition to the traditional hybrid clutch.

[0008] However, due to the drawbacks of HEV and PHEV hybrid systems equipped with transmission-mounted electric devices (TMED), namely the decrease in the state of charge (SOC) of the battery during uphill driving, alternative solutions are needed to address the issues of reduced driving capability and fuel efficiency.

[0009] To describe in more detail, in a TMED hybrid system, when the minimum speed (RPM) at which the engine is normally controlled during the initial phase of vehicle acceleration is called the engageable speed, the vehicle accelerates at a speed greater than or equal to the engageable speed by engaging (locking up) the engine clutch and then utilizing engine power. However, at speeds below the engageable speed, since the electric motor is responsible for vehicle acceleration, there are issues such as... Figure 1 The battery discharge region is shown.

[0010] Therefore, when continuously driving uphill, which requires a large amount of battery power, the State of Charge (SOC) may decrease due to continuous battery discharge.

[0011] When the vehicle accelerates with a low battery SOC, the TMED hybrid system utilizes engine power by slipping the engine clutch. However, since a conventional engine clutch does not have sufficient slipping capacity to function as an acceleration clutch, and in TMED hybrid systems equipped with a DCT, there are cases where lightweight materials are used that are configured to only open / close (engage / disengage) the engine clutch, thus limiting the use of the engine clutch.

[0012] Furthermore, when the driver operates the gear shifting mode in manual shifting mode, the degree of freedom of control is reduced, which limits the protection of the battery's SOC value and increases the possibility of problems.

[0013] For example, refer to Figure 2 The description is as follows: when the vehicle is traveling uphill in second gear, because the engine torque (150 Nm) is greater than the torque required by the driver (100 Nm), the electric motor uses the remaining engine torque (50 Nm) as a generator (in this case, the motor torque is a negative torque of -50 Nm), so that the battery can be charged.

[0014] However, when a driver intentionally shifts to third gear on an uphill road using manual shift mode and then drives the vehicle, because the engine torque (80 Nm) is less than the driver's required torque (100 Nm), an additional 20 Nm of motor torque can be generated to meet the driver's torque demand. In this situation, the motor consumes electricity, causing the battery to discharge.

[0015] When this situation continues, the battery's SOC value may drop below the limit level due to excessive discharge, potentially rendering the vehicle unable to operate.

[0016] In addition, during low-speed uphill driving, the engine clutch slips at low speed (low RPM) in manual shift mode, which may lead to excessive battery discharge and a decrease in SOC and driving capability.

[0017] Furthermore, in manual shift mode, the inability to predict shift points makes it difficult to provide a smooth shift feel, limiting regenerative braking and making it almost impossible to recharge during downhill driving, thus contributing to decreased fuel efficiency.

[0018] The information included in this background section of the invention is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0019] Various aspects of the present invention are dedicated to providing a method for controlling the uphill driving of a vehicle, configured to ensure the state of charge (SOC) value of the battery by minimizing battery discharge, and configured to minimize energy consumption in the acceleration region.

[0020] In another aspect, various aspects of the present invention provide a method for controlling uphill driving of a vehicle, configured to minimize the decrease in driving capability and fuel efficiency caused by battery discharge and a decrease in SOC during uphill driving of the vehicle.

[0021] The objectives of this invention are not limited to those described above, and other objectives of the invention not mentioned herein may be understood from the following description and will also be apparent from embodiments of the invention. Furthermore, the objectives of this invention may be achieved by the methods and combinations thereof described in the appended claims.

[0022] In various exemplary embodiments of the present invention, aspects of the present invention provide a method for controlling uphill driving of a hybrid vehicle equipped with a dual-clutch transmission (DCT), the method comprising: determining the driving state of the vehicle by a controller based on information collected from the vehicle; when the vehicle is determined to be in an uphill driving state, controlling the engine by increasing engine torque to control the engine at a predetermined high torque engine operating point and reducing the motor torque of the electric motor in the vehicle to meet the torque demand of the driver, the controller performing high torque control on the engine; and during the high torque control of the engine, comparing the state of charge (SOC) value of the battery with a set first SOC threshold, and when the SOC value of the battery is less than or equal to the first SOC threshold, performing engine and motor speed control to protect the SOC value of the battery.

[0023] Furthermore, the method for controlling the vehicle's uphill driving can further include: when performing engine and motor speed control, the controller compares the battery's SOC value with a set second SOC threshold, and when the battery's SOC value is less than or equal to the second SOC threshold, it determines that the battery's SOC value is in a low SOC state; in the low SOC state, the controller determines the DCT's slip speed based on the DCT's capacity and the current driver's required torque, and determines whether the engine speed has reached the determined DCT slip speed; when the engine speed reaches the DCT slip speed, the controller controls the engine clutch between the engine and the motor to be locked and performs slip control on the DCT clutch, thereby operating the motor to generate electricity using the remaining engine power after driving the vehicle, so that the motor charges the battery.

[0024] Furthermore, the method for controlling the vehicle's uphill driving can further include: before the engine speed reaches the DCT slip speed, when the engine clutch is disengaged, the controller uses the engine power to operate the hybrid starter generator (HSG) to generate electricity to force the battery to be charged by the engine.

[0025] In another exemplary embodiment of the invention, when the vehicle is determined to be in an uphill driving state, the controller can be configured to determine whether a manual shift mode is currently selected, and when a manual shift mode is not selected, to control the engine at a predetermined high torque engine operating point by increasing engine torque and decreasing motor torque to meet the driver's torque requirements, the controller can perform high torque control on the engine.

[0026] In another exemplary embodiment of the present invention, when the manual shift mode is selected, the controller can compare the SOC value of the battery with a set third SOC threshold, and when the SOC value of the battery is less than or equal to the third SOC threshold, the controller can be configured to control the engine clutch between the engine and the motor to be locked, and can control the DCT clutch to slip, thereby operating the motor to generate electricity using the remaining engine power after driving the vehicle, so that the motor can charge the battery.

[0027] Furthermore, in yet another exemplary embodiment of the present invention, when the battery is being charged by the motor, if the amount of discharge of the battery during a set time period becomes greater than a predetermined third discharge reference value, the controller may execute a ramp mode to forcibly release the manual shift mode.

[0028] Other aspects and exemplary embodiments of the invention are discussed below.

[0029] It should be understood that the term "vehicle" or "of a vehicle" or other similar terms as used herein generally includes motor vehicles, such as passenger vehicles including sport utility vehicles (SUVs), buses, trucks, various commercial vehicles, vessels including various boats and ships, aircraft, etc., and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other alternative fuel vehicles (e.g., vehicles powered by non-petroleum energy sources). As mentioned herein, a hybrid vehicle is a vehicle with two or more power sources, such as both gasoline and electric power.

[0030] The above and other features of the invention are discussed below.

[0031] The methods and apparatus of the present invention have other features and advantages that will be apparent from or set forth in detail in the accompanying drawings and following detailed description, which together serve to explain the particular principles of the invention. Attached Figure Description

[0032] Figure 1 It is a graph showing the potential battery discharge area when a hybrid vehicle is driving uphill;

[0033] Figure 2 This is a schematic diagram illustrating the potential battery discharge caused by the electric motor when a hybrid vehicle is driving uphill and shifting gears.

[0034] Figure 3 This is a schematic diagram illustrating the configuration of a vehicle's powertrain, which is configured to apply a method for controlling uphill driving according to various exemplary embodiments of the present invention.

[0035] Figure 4 This is a block diagram illustrating a controller and hardware configured to perform uphill driving control of a vehicle according to various exemplary embodiments of the present invention;

[0036] Figure 5 This is a flowchart illustrating a method for controlling a vehicle to travel uphill according to various exemplary embodiments of the present invention; and

[0037] Figure 6 and Figure 7 This is a schematic diagram illustrating the uphill driving control state of a vehicle according to various exemplary embodiments of the present invention.

[0038] It is understood that the accompanying drawings are not necessarily drawn to scale, but rather show slightly simplified depictions of various exemplary features illustrating the basic principles of the invention. Specific design features of the invention as included herein (including, for example, specific dimensions, orientations, positions, and shapes) will be determined in part by the specific environment in which they are intended to be applied and used.

[0039] In the accompanying drawings, reference numerals throughout the multiple figures indicate the same or equivalent parts of the invention. Detailed Implementation

[0040] Reference will now be made in detail to various embodiments of the invention, examples of which are illustrated in the accompanying drawings and described below. Although the invention will be described in conjunction with exemplary embodiments thereof, it will be understood that this specification is not intended to limit the invention to those exemplary embodiments. On the contrary, the invention is intended to cover not only the exemplary embodiments thereof, but also various alternatives, modifications, equivalents, and other embodiments that may be included within the spirit and scope of the invention as defined by the appended claims.

[0041] Hereinafter, embodiments of the invention will be fully described with reference to the accompanying drawings in detail suitable for implementation by those skilled in the art. However, the invention is not limited to the exemplary embodiments included herein and may be implemented in other forms.

[0042] Throughout the specification, when an element is referred to as “comprising” or “including” a component, this means that the component may further include other components, and other components are not excluded unless otherwise stated.

[0043] Various aspects of the present invention provide a method for controlling uphill driving of a vehicle, configured to always ensure a suitable state of charge (SOC) value of the battery by minimizing battery discharge during uphill driving, and configured to minimize energy consumption in the acceleration region.

[0044] Furthermore, various aspects of the present invention provide a method for controlling uphill driving of a vehicle, configured to minimize the decrease in driving capability and fuel efficiency caused by battery discharge and SOC reduction during uphill driving of the vehicle.

[0045] This invention applies to electrified vehicles driven by an electric motor. It also applies to hybrid vehicles driven by both an engine and an electric motor, and furthermore, to hybrid vehicles equipped with a dual-clutch transmission (DCT) as the transmission.

[0046] Figure 3This is a schematic diagram illustrating the configuration of the powertrain of a hybrid vehicle configured to apply a method for controlling uphill driving according to various exemplary embodiments of the present invention, showing a transmission-mounted electric device (TMED) hybrid system of a vehicle equipped with a DCT 14.

[0047] As shown in the figure, the TMED hybrid system includes: an engine 11 and an electric motor 13 as drive units for driving the vehicle, an engine clutch 12 installed between the engine 11 and the electric motor 13, and a DCT 14 connected to the output side of the electric motor 13.

[0048] In addition, the vehicle includes a hybrid starter and generator (HSG) 16, an inverter 17, and a battery 18; the HSG 16 is a motor configured to start the engine 11; the inverter 17 is used to drive and control the motor 13 and the HSG 16; the battery 18 is rechargeably and dischargeably connected to the motor 13 and the HSG 16 via the inverter 17, which serves as the power source (power supply) for the motor 13 and the HSG 16.

[0049] In the TMED hybrid system, the motor 13 used to drive the vehicle is connected to the drive wheels 15 via the DCT 14 in a power transmission manner. Therefore, the power of the battery 18 can be used to drive the motor 13 to provide rotational force to the drive wheels 15, and conversely, the rotational force of the drive wheels 15 can be received to generate electricity to charge the battery 18.

[0050] The engine clutch 12 performs a locking or disengaging operation to connect or disconnect the engine 11 and the motor 13 in a power transmission manner, and the DCT 14 changes the speed of the rotational power transmitted from the motor 13 to transmit the rotational power to the drive wheel 15 via the drive shaft.

[0051] In order to drive motor 13 and HSG 16, inverter 17 is configured to convert the direct current (DC) of battery 18 into three-phase alternating current (AC) to apply three-phase AC current to motor 13 and HSG 16, and during the driving of motor 13 and HSG 16, battery 18 supplies power or is charged during the power generation operation of motor 13 and HSG 16.

[0052] Meanwhile, the present invention includes a control process for protecting the SOC value of battery 18 during uphill driving. In order to perform the control process for protecting the SOC value of battery 18, controller 10: determines that the vehicle is currently driving uphill; when the vehicle is currently driving uphill under high load, executes high torque control of the engine to increase engine torque; and when battery 18 is over-discharged, protects the SOC value of battery 18 by controlling the speed of engine 11 and motor 13.

[0053] Here, battery 18 is a battery located in the vehicle that supplies drive power (or discharges) to motor 13, and receives and stores the power generated by motor 13 (or charges it) when motor 13 is operating as a generator. The SOC value (%) of the battery indicates the remaining charge of battery 18.

[0054] Furthermore, the SOC value of the protection battery 18 represents a series of processes for maintaining and managing the SOC value of the battery 18 so that it does not drop below a predetermined limit value.

[0055] exist Figure 3 In the hybrid system shown, when the engine 11 is in the driving state and the engine clutch 12 is in the locked state, when the power of the engine 11 is transmitted to the motor 13 via the engine clutch 12, the motor 13 can operate as a generator due to the power of the engine 11 to charge the battery 18 ("motor charging").

[0056] Furthermore, the present invention includes an uphill driving control process when the battery 18 enters a low SOC state. During the uphill driving control process, forced charging control of the engine 11 is performed before the engine 11 speed (RPM) reaches the slip speed of the DCT 14.

[0057] Here, the forced charging control for engine 11 refers to the control used to perform a series of processes in which engine 11 is driven so that HSG 16 operates as a generator using engine power so that battery 18 is charged by HSG 16.

[0058] Furthermore, during uphill driving control when the battery 18 enters a low SOC state, after the engine 11 reaches the slippage speed of the DCT 14, clutches 14a and 14b (hereinafter referred to as "DCT clutches") in the DCT 14 become slippageable, causing the engine clutch 12 to lock and slippage control to be applied to the DCT clutches 14a and 14b (slippage control applied to one of the DCT clutches 14a and 14b). Therefore, a portion of the engine power is transmitted to the drive wheels 15 to drive the vehicle, and the electric motor 13 utilizes the remaining engine power to operate as a generator to charge the battery 18.

[0059] Furthermore, the present invention includes a control process for ensuring the SOC value of the battery 18 in manual shift mode during uphill driving. In this control process, slip control is applied to the DCT clutches 14a and 14b, and in the event of excessive discharge of the battery 18, a ramp mode is executed to forcibly disengage the manual shift mode.

[0060] The method for controlling a vehicle to travel uphill according to various exemplary embodiments of the present invention can be executed by a controller in the vehicle. The invention will now be described in more detail with respect to each detailed process executed by the controller.

[0061] Figure 4 This is a block diagram illustrating a controller and hardware configured to perform uphill driving control of a vehicle according to various exemplary embodiments of the present invention; Figure 5 This is a flowchart illustrating a method for controlling a vehicle to travel uphill according to various exemplary embodiments of the present invention.

[0062] Control process to protect the battery's SOC value during uphill driving.

[0063] First, the controller 10 determines the vehicle's current driving state based on information collected from the vehicle. The controller 10 determines whether the vehicle is currently performing high-discharge uphill driving or low-discharge uphill driving.

[0064] In this case, the controller 10 compares the discharge amount ΔSOC value of the battery 18 during the set time period with predetermined discharge amount reference values ​​α and β (steps S11 and S12). When the discharge amount of the battery 18 during the set time period is greater than or equal to the predetermined first discharge amount reference value α and less than the predetermined second discharge amount reference value β, the controller 10 can determine that the vehicle is in a low-discharge uphill driving situation.

[0065] Furthermore, when the discharge amount of battery 18 during a set time period is greater than or equal to a predetermined second discharge amount reference value β, the controller 10 can determine that the vehicle is in a high-discharge uphill driving situation.

[0066] Here, the discharge amount of battery 18 represents the change in SOC of battery 18, ΔSOC. The discharge amount of battery 18 represents the change in SOC of battery 18 under discharge conditions, ΔSOC, that is, the amount by which the SOC value of battery 18 decreases.

[0067] Furthermore, the discharge amount of battery 18 during the set time period can be the total discharge amount of battery 18 during the set time period or the average discharge amount of battery 18 during the set time period (discharge power of battery 18). In this case, the average value can be the average value obtained by the moving average method.

[0068] The set time is sufficient to determine the discharge status of battery 18 and is set in controller 10. The first discharge amount reference value α can be set to a value corresponding to the amount of SOC change when entering from the center SOC to a predetermined low SOC (second SOC threshold, which will be described below), and the second discharge amount reference value β can be set to a value corresponding to the amount of SOC change when entering from the center SOC to a predetermined idle charging SOC.

[0069] For example, the set time can be set to 100 seconds, the first discharge reference value α can be set to 12% based on the SOC value of battery 18, and the second discharge reference value β can be set to 20% based on the SOC value of battery 18.

[0070] In this case, when the SOC value of battery 18 drops to greater than or equal to 12% and less than 20% for 100 seconds, controller 10 determines low discharge uphill driving, and when the SOC value of battery 18 drops to greater than or equal to 20% for 100 seconds, controller 10 determines high discharge uphill driving.

[0071] The set time, the first discharge quantity reference value α, and the second discharge quantity reference value β are preset values ​​in the controller 10 and determined through a pre-testing and evaluation process for use after being input and stored in the controller 10. The above values ​​are merely examples, and the invention is not limited thereto; various changes can be made to the above values.

[0072] Next, when the controller 10 determines that the situation is high-discharge uphill driving, the controller 10 performs high torque control on the engine 11 (step S13).

[0073] During high torque control, the driver's torque demand is met by both engine torque and electric motor torque. Engine torque is increased to execute high torque control at a predetermined high torque engine operating point, while simultaneously, electric motor torque is decreased to meet the driver's torque demand.

[0074] In this configuration, engine torque control is implemented to guide the high-torque engine operating point to converge to a preset Part-Load Max. line. Therefore, engine 11 outputs a high level of torque, thereby minimizing the decrease in the SOC value of battery 18 due to the drive of motor 13.

[0075] Part-Load Max. is defined as the maximum torque or maximum power when the engine is controlled at Lambda(λ)1 (=actual air-fuel ratio / engine stoichiometric air-fuel ratio). That is, the region above Part-Load Max. is when the engine is controlled at λ<1, while the region equal to or less than Part-Load Max. is when the engine can be controlled at λ=1.0.

[0076] Furthermore, during high torque control, the controller 10 compares the current SOC value of the battery 18 with a preset first SOC threshold γ (step S14), and when the current SOC value of the battery 18 is less than or equal to the first SOC threshold γ, the controller 10 performs speed control on the engine 11 and the motor 13 to protect the current SOC value of the battery 18 (step S15).

[0077] Here, the first SOC threshold γ can be set to the SOC value at which idling charging begins.

[0078] In various exemplary embodiments of the invention, engine and motor speed control is performed with limitations in a mode where it is necessary to protect the SOC value of battery 18 as much as possible. During the execution of engine and motor speed control, controller 10 controls engine clutch 12 to be in a locked (engaged) state and DCT clutches 14a and 14b to be in a slipped state.

[0079] Furthermore, when the process of executing engine and motor speed control is initiated, the controller 10 determines the target speed of the engine 11 as the speed obtained by adding a predetermined speed value A to the output speed of the DCT 14, and then controls the rotational speed of the engine 11 to the determined target speed during the process of executing engine and motor speed control.

[0080] In this situation, since the engine clutch 12 is locked, the speed of the motor 13 is kept equal to the speed of the engine 11, and when the vehicle is traveling in the slip state of the DCT clutches 14a and 14b, the high speed of the engine 11 is maintained so that the engine power can be fully guaranteed, thereby minimizing the release of the SOC value of the battery 18.

[0081] In other words, the control state can be summarized as follows.

[0082] Engine clutch: locked

[0083] DCT clutch: slip

[0084] Engine speed = Motor speed = DCT output speed + A

[0085] Here, the DCT output speed can be obtained from the signal of the wheel speed sensor installed in the drive wheel 15, and A can be a speed value determined according to the DCT clutch capacity, and can be predetermined based on the maximum speed difference between the transmission input speed and the transmission output speed according to the DCT clutch capacity.

[0086] Simultaneously, during engine and motor speed control, the controller 10 compares the SOC value of the battery 18 with a preset second SOC threshold δ (step S16). In this case, when the SOC value of the battery 18 is less than or equal to the second SOC threshold δ, the controller 10 determines that it has entered a low SOC state to execute a predetermined uphill driving control process.

[0087] Here, the second SOC threshold δ is set to a value less than the first SOC threshold γ (i.e., γ > δ).

[0088] 2) Uphill driving control process when entering low SOC

[0089] When the controller 10 determines that the battery 18 has entered a low SOC state, the controller 10 determines the DCT slip speed under the current driver's required torque based on the DCT capacity, and the DCT slip speed can be determined by the following Equation 1.

[0090] [Equation 1]

[0091] DCT slip speed = Maximum DCT slip speed difference - Minimum engine speed

[0092] Here, the minimum engine speed is the speed predetermined by the engine 11 and set in the controller 10 (e.g., 1000 rpm), and the maximum DCT slip speed difference can be determined by the following equation 2.

[0093] [Equation 2]

[0094] Maximum DCT slip speed difference = [DCT capacity (kW) - power demand (kW)] / driver's required torque (Nm)

[0095] Here, the DCT capacity is a preset value in controller 10 and can be referred to as the DCT clutch capacity. However, since there are two clutches in DCT 14, the DCT capacity can vary depending on which clutch is in use.

[0096] In addition, the power demand is a value calculated based on the driver's acceleration intention (e.g., accelerator position sensor (APS) signal value), and the ordinary vehicle is controlled by determining the power demand based on the driver's acceleration intention in the ordinary vehicle.

[0097] As described above, when the DCT slip speed is determined, the controller 10 compares the current engine speed with the DCT slip speed to determine whether the engine speed has reached the DCT slip speed (step S17).

[0098] Here, DCT clutches 14a and 14b cannot slip before the engine speed reaches the DCT slippage speed. Therefore, as Figure 6 As shown, controller 10 disengages engine clutch 12 and then performs forced engine charging control (step S18).

[0099] In this situation, the controller 10 operates the HSG 16 to generate electricity as engine power, uses the electricity generated by the HSG 16 to charge the battery 18, and at the same time, immediately drives the motor 13, thereby minimizing the loss of charging and discharging.

[0100] Furthermore, with the DCT clutch 14a engaged, the controller 10 transmits motor power to the drive wheels 15, allowing the vehicle to move using the motor power.

[0101] Furthermore, after the engine speed reaches the DCT slippage speed, the DCT clutches 14a and 14b are slippage-enabled. Therefore, as... Figure 7 As shown, the controller 10 controls the engine clutch 12 to be locked and controls the DCT clutch 14a to slip (step S19).

[0102] In this configuration, a portion of the engine power is transmitted to the drive wheels 15, enabling the vehicle to move, and the remaining energy (i.e., the remaining engine power) can operate the motor 13 to generate electricity, allowing the battery 18 to be charged using the electricity generated by the motor 13.

[0103] 3) Ensure the control process of battery SOC value during uphill driving in manual shift mode.

[0104] Meanwhile, when the controller 10 determines that the vehicle is in a low-discharge uphill driving state, that is, in steps S11 and S12, the controller 10 determines that the discharge amount of the battery 18 during the set time period is greater than or equal to the first discharge amount reference value α and less than the second discharge amount reference value β, and the controller 10 determines whether the manual shift mode is currently selected (step S20).

[0105] Here, when the manual shift mode is not selected, in step S25, high torque control is performed on engine 11 in the same manner as in step S13.

[0106] Meanwhile, when the current state is low discharge uphill driving and manual shift mode, after entering the uphill driving manual shift mode, the controller 10 compares the current SOC value of the battery 18 with the third SOC threshold ε (step S21).

[0107] When the current SOC value of battery 18 is less than or equal to the third SOC threshold ε, controller 10 executes DCT clutch slip control (step S22).

[0108] Here, the third SOC threshold ε can be set to a typical low SOC entry reference value, and when the capacity of battery 18 is less than the normal level, the third SOC threshold ε can be set to a value greater than or equal to the typical low SOC entry reference value.

[0109] The third SOC threshold ε can be equal to or different from the second SOC threshold δ. When the third SOC threshold ε is different from the second SOC threshold δ, the third SOC threshold ε can be greater than or equal to the second SOC threshold δ.

[0110] As described above, in a low SOC state where the current SOC value of battery 18 is less than or equal to the third SOC threshold ε, gear shifting will not be performed arbitrarily and the desired gear will be maintained. In this case, such as Figure 7 As shown, with the engine clutch 12 locked, the controller 10 controls the DCT clutch 14a to slip, thus transmitting a portion of the engine power to the drive wheels 15, enabling the vehicle to move. Simultaneously, the controller 10 operates the motor 13 to generate electricity using the remaining energy (i.e., the remaining engine power), allowing the battery 18 to be charged using the electricity generated by the motor 13.

[0111] As described above, while performing slip control on the DCT clutch, the controller 10 compares the discharge amount ΔSOC of the battery 18 during a set time period with a preset third discharge amount reference value ζ (step S23). When the discharge amount ΔSOC of the battery 18 during the set time period becomes greater than the third discharge amount reference value ζ, the controller 10 executes the ramp mode (step S24).

[0112] Here, the discharge amount ΔSOC of battery 18 during the set time period can be defined as equal to the discharge amount of battery 18 during the set time period in steps S11 and S12.

[0113] Furthermore, the third discharge quantity reference value ζ can be the same as one of the first discharge quantity reference values ​​α and the second discharge quantity reference value β. Alternatively, the third discharge quantity reference value ζ can be different from both the first discharge quantity reference value α and the second discharge quantity reference value β.

[0114] For example, when the third discharge reference value ζ is set to 20% and the discharge amount ΔSOC of battery 18 is greater than or equal to 20% of the SOC value of battery 18, ramp mode is executed.

[0115] Furthermore, when the ramp mode is in operation, even if the driver switches the shift mode to manual shift mode, the controller 10 forcibly cancels the manual shift mode and performs shift control according to the shift mapping.

[0116] In this situation, the controller 10 can be configured to notify the driver via a notification unit that the manual shift mode has been forcibly deactivated. For example, the controller 10 displays a deactivation message on the instrument cluster, such as "Manual shift mode deactivated due to excessive battery discharge," to inform the driver of the current situation.

[0117] In the above description, although it has been described that the vehicle is currently in a high-discharge uphill driving situation based on the discharge amount of the battery 18 during a set time period, and then high torque control is performed on the engine 11, or that the vehicle is currently in a low-discharge uphill driving situation based on the discharge amount of the battery 18 during a set time period, and at the same time, the current state is determined to be manual shift mode, high torque control is performed. However, without detailed classification, when the vehicle is in an uphill driving situation and the current mode is not manual shift mode, the controller 10 may be set to perform high torque control in step S13 on the engine 11.

[0118] In this case, as described above, steps S14 to S19 can be performed after step S13.

[0119] Furthermore, in this case, when the vehicle is driving uphill and in manual shift mode, the controller 10 can be set to execute steps S21 to S24.

[0120] Furthermore, the controller 10 can determine whether the vehicle is performing uphill driving based on the slope information about the current driving road collected from the vehicle. Slope (inclination) information about the current driving road can be obtained from signals from sensors in the vehicle.

[0121] Here, the sensor can be a longitudinal acceleration sensor. When the vehicle is moving, the signal output from the longitudinal acceleration sensor can be used to obtain information about the slope of the current road.

[0122] The methods and processes for obtaining slope information from signals from longitudinal acceleration sensors are well-known techniques to those skilled in the art, and therefore, their detailed description will be omitted in this document.

[0123] As described above, the method for controlling uphill driving according to various exemplary embodiments of the present invention can be applied to hybrid vehicles equipped with DCT, thereby fully protecting the SOC value of the battery during uphill driving to minimize full load entry and also reducing the idling charging area to improve the vehicle's fuel efficiency.

[0124] Furthermore, when driving uphill at low SOC, the system can prioritize protecting the battery's SOC value and minimize factors that reduce driving capability (such as excessive engine noise, shocks caused by low-gear slip control, etc.), thereby significantly improving the vehicle's marketability.

[0125] As described above, the method for controlling a vehicle's uphill driving based on various exemplary embodiments of the present invention can minimize battery discharge to ensure the battery's state of charge (SOC) value and minimize energy consumption in the acceleration zone. Therefore, the vehicle's fuel efficiency can be improved, and the decrease in driving capability and fuel efficiency caused by discharge and the decrease in battery SOC value can be minimized.

[0126] Furthermore, the term "controller" refers to a hardware device including a memory and a processor configured to execute one or more steps interpreted as an algorithmic structure. The memory stores the algorithmic steps, and the processor executes the algorithmic steps to perform one or more processes of methods according to various exemplary embodiments of the invention. A controller according to an exemplary embodiment of the invention may be implemented using non-volatile memory and a processor configured to store algorithms for controlling the operation of various components of a vehicle or data regarding software commands for executing the algorithms, the processor being configured to perform the aforementioned operations using the data stored in the memory. The memory and processor may be separate chips. Alternatively, the memory and processor may be integrated into a single chip. The processor may be implemented as one or more processors.

[0127] The controller may be at least one microprocessor operated by a predetermined program, which may include a series of commands for performing methods according to various exemplary embodiments of the present invention.

[0128] The foregoing invention can also be implemented as computer-readable code on a computer-readable recording medium. A computer-readable recording medium is any data storage device capable of storing data that can subsequently be read by a computer system. Examples of computer-readable recording media include hard disk drives (HDDs), solid-state drives (SSDs), silicon disk drives (SDDs), read-only memory (ROM), random access memory (RAM), CD-ROMs, magnetic tapes, floppy disks, optical data storage devices, etc., and are implemented as carrier waves (e.g., transmitted over the Internet).

[0129] For ease of interpretation and precise definition of the appended claims, the terms “upper,” “lower,” “inner,” “outer,” “above,” “below,” “upward,” “downward,” “front,” “back,” “rear,” “inner,” “outer,” “inward,” “outer,” “internal,” “external,” “inner side,” “outer side,” “forward,” and “backward” are used to describe features of the exemplary embodiments with reference to the positions of these features shown in the accompanying drawings. It will be further understood that the term “connection” or its derivatives refer to both direct and indirect connections.

[0130] Furthermore, the term "fixed connection" means that the components of a fixed connection always rotate at the same speed. Additionally, the term "selectively connected" means that when the selectively connected components are not engaged with each other, they rotate separately; when they are engaged with each other, they rotate at the same speed; and when at least one of the selectively connected components is a stationary component and the remaining selectively connected components are engaged with that stationary component, these selectively connected components are stationary.

[0131] The foregoing description of specific exemplary embodiments of the present invention is for illustrative and descriptive purposes. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed; obviously, many modifications and variations are possible in light of the foregoing teachings. The exemplary embodiments were chosen and described to explain the specific principles of the invention and its practical application, thereby enabling others skilled in the art to implement and utilize various exemplary embodiments of the invention, as well as their various alternatives and modifications. The scope of the invention is intended to be defined by the appended claims and their equivalents.

Claims

1. A method for controlling the uphill driving of a vehicle equipped with a dual-clutch transmission, the method comprising: The controller determines the vehicle's driving status based on information collected from the vehicle. When it is determined that the vehicle is driving uphill, the engine torque is increased to control the engine at a predetermined high torque engine operating point, and the motor torque in the vehicle is reduced to meet the driver's torque requirements. The controller performs high torque control on the vehicle's engine. During the process of performing high torque control on the engine, the controller compares the battery's state of charge value with a predetermined first state of charge threshold. When it is determined that the battery's state of charge value is less than or equal to the first state of charge threshold, the controller performs engine and motor speed control to protect the battery's state of charge value. When performing engine and motor speed control, the controller compares the battery's state of charge value with a predetermined second state of charge threshold, and determines that the battery's state of charge value is in a low state when it is determined that the battery's state of charge value is less than or equal to the second state of charge threshold. In the low battery state, the controller determines the slip speed of the dual-clutch transmission based on the capacity of the dual-clutch transmission and the current torque demand of the driver, and determines whether the engine speed reaches the determined slip speed of the dual-clutch transmission. When the engine speed is determined to reach the slip speed of the dual-clutch transmission, the controller locks the engine clutch between the engine and the motor and slips the dual-clutch transmission clutch, thereby operating the motor to generate electricity using the remaining engine power after driving the vehicle, so that the motor can charge the battery.

2. The method according to claim 1, wherein, When determining the vehicle's driving status, the controller is configured to compare the battery's discharge amount during a predetermined time period with a predetermined discharge amount reference value to determine whether the vehicle is in a high-discharge uphill driving state, and when it is determined that the vehicle is in a high-discharge uphill driving state where the discharge amount during the predetermined time period is greater than or equal to the predetermined discharge amount reference value, the controller is configured to perform high-torque control on the engine.

3. The method according to claim 1, wherein, When performing high torque control on the engine, the controller is configured to control the engine torque at the engine operating point that converges to the Part-Load Max. line.

4. The method according to claim 1, wherein, When performing engine and motor speed control, the controller is configured to: control the engine clutch between the engine and the motor to be in a locked state; control the dual-clutch transmission clutch to be in a slip state; and set the speed obtained by adding the speed value based on the capacity of the dual-clutch transmission clutch to the output speed of the dual-clutch transmission as the target speed of the engine, thereby controlling the engine speed.

5. The method according to claim 4, wherein, The speed value based on the clutch capacity of the dual-clutch transmission is the maximum speed difference between the transmission input speed and the transmission output speed, and the maximum speed difference is determined based on the clutch capacity of the dual-clutch transmission.

6. The method of claim 1, further comprising: Before the engine speed reaches the slip speed of the dual-clutch transmission, when it is determined that the engine clutch is in the disengaged state, the controller performs a forced engine charging operation to charge the battery by using engine power to operate the hybrid starter generator.

7. The method according to claim 6, wherein, During forced engine charging, the controller is configured to engage the dual-clutch transmission clutch and drive the motor, causing the vehicle to move due to the motor's power.

8. The method according to claim 1, wherein, When it is determined that the vehicle is driving uphill, the controller is configured to determine whether the manual shifting mode is currently selected. When it is determined that the manual shifting mode is not selected, the controller is configured to perform high torque control on the engine by increasing the engine torque to control the engine at a predetermined high torque engine operating point and decreasing the motor torque to meet the driver's torque requirements.

9. The method according to claim 8, wherein, During high torque control of the engine, the controller is configured to control the engine torque at the engine operating point that converges to the Part-Load Max. line.

10. The method according to claim 8, wherein, When it is determined that the manual shift mode has been selected, the controller is configured to compare the battery's state of charge value with a predetermined third state of charge threshold. When it is determined that the battery's state of charge value is less than or equal to the third state of charge threshold, the controller is configured to lock the engine clutch between the engine and the motor and slip the dual-clutch transmission clutch to operate the motor to generate electricity using the remaining engine power after driving the vehicle, so that the motor charges the battery.

11. The method according to claim 10, wherein, When the battery is being charged by the motor, if it is determined that the amount of battery discharge during a predetermined time period becomes greater than or equal to a predetermined third discharge reference value, the controller is configured to execute a ramp mode to deactivate the manual shift mode.

12. The method according to claim 2, wherein, The predetermined discharge quantity reference value includes the second discharge quantity reference value; When determining the vehicle's driving status, in response to the vehicle being determined to be in a low-discharge uphill driving state, the controller is configured to determine whether a manual shifting mode is currently selected, in which the battery discharge amount during a predetermined time period is greater than or equal to a predetermined first discharge amount reference value and less than a second discharge amount reference value, and when it is determined that no manual shifting mode is selected, the controller is configured to perform high torque control on the engine by increasing the engine torque to control the engine at a predetermined high torque engine operating point and decreasing the motor torque to meet the driver's torque requirements.

13. The method according to claim 12, wherein, During high torque control of the engine, the controller is configured to control the engine torque at the engine operating point that converges to the Part-Load Max. line.

14. The method according to claim 2, wherein, The predetermined discharge quantity reference value includes the second discharge quantity reference value; When determining the vehicle's driving status, in response to the vehicle being determined to be in a low-discharge uphill driving state, the controller is configured to determine whether a manual shifting mode is currently selected. In the low-discharge uphill driving state, the battery discharge amount during a predetermined time period is greater than or equal to a predetermined first discharge amount reference value and less than a second discharge amount reference value. When it is determined that a manual shifting mode is selected, the controller is configured to compare the battery's state of charge value with a predetermined third state of charge threshold. When it is determined that the battery's state of charge value is less than the third state of charge threshold, the controller is configured to control the engine clutch between the engine and the motor to be locked and control the dual-clutch transmission clutch to slip, thereby operating the motor to generate electricity using the remaining engine power after driving the vehicle, so that the motor charges the battery.

15. The method according to claim 14, wherein, When the battery is being charged by the motor, if it is determined that the amount of battery discharge during a predetermined time period becomes greater than or equal to a predetermined third discharge reference value, the controller is configured to execute a ramp mode to deactivate the manual shift mode.

16. The method according to claim 1, wherein, The controller includes: Processor; and A non-volatile storage medium having a program recorded thereon for performing the method according to claim 1 and executed by a processor.

17. A non-volatile computer-readable medium having a program thereon for performing the method according to claim 1.

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