阅读说明：本技术 控制车辆的上坡行驶的方法 (Method for controlling uphill driving of vehicle ) 是由 许志旭 于 2020-11-30 设计创作，主要内容包括：本发明涉及一种控制车辆的上坡行驶的方法。一种控制设置有双离合器变速器(DCT)的混合动力车辆的上坡行驶的方法可以包括：由控制器根据从车辆收集到的信息确定车辆的行驶状态；当车辆被确定为处于上坡行驶状态时,通过增大发动机扭矩以在预定的高扭矩发动机工作点控制发动机并且减小车辆中的电机的电机扭矩以满足驾驶员需求扭矩,由控制器对车辆的发动机执行高扭矩控制；并且在对发动机执行高扭矩控制过程中,由控制器将电池的电量状态(SOC)值与设定的第一SOC阈值进行比较,并且当电池的SOC值小于或等于第一SOC阈值时,执行发动机和电机速度控制,以保护电池的SOC值。(The present invention relates to a method of controlling uphill driving of a vehicle. A method of controlling uphill driving of a hybrid vehicle provided with a Dual Clutch Transmission (DCT) may include: determining, by the controller, a driving state of the vehicle based on the information collected from the vehicle; performing, by a controller, high torque control on an engine of a vehicle by increasing the engine torque to control the engine at a predetermined high torque engine operating point and decreasing a motor torque of a motor in the vehicle to meet a driver required torque when the vehicle is determined to be in an uphill driving state; and comparing, by the controller, a state of charge (SOC) value of the battery with a set first SOC threshold value during the execution of the high torque control on the engine, and executing 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.)

1. A method of controlling uphill travel of a vehicle provided with a dual clutch transmission, the method comprising:

determining, by the controller, a driving state of the vehicle based on the information collected from the vehicle;

performing, by a controller, high torque control of an engine of a vehicle by increasing the engine torque to control the engine at a predetermined high torque engine operating point and decreasing a motor torque of a motor in the vehicle to meet a driver required torque when it is determined that the vehicle is in an uphill driving state;

during execution of the high torque control of the engine, a state of charge value of a battery of the vehicle is compared by the controller with a predetermined first state of charge threshold value, and when it is determined that the state of charge value of the battery is less than or equal to the first state of charge threshold value, engine and motor speed control is executed by the controller to protect the state of charge value of the battery.

2. The method according to claim 1, wherein, when determining the running state of the vehicle, the controller is configured to compare a discharged amount of the battery for a predetermined time with a predetermined discharged amount reference value to determine whether the vehicle is in a high-discharge uphill running state, and when it is determined that the vehicle is in a high-discharge uphill running state in which the discharged amount for the predetermined time is greater than or equal to the predetermined discharged amount reference value, the controller is configured to perform high-torque control on the engine.

3. The method of claim 1, wherein, in performing high torque control on the engine, the controller is configured to control engine torque at an engine operating point that converges on a Part-Load max.

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

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

6. The method of claim 1, further comprising:

comparing, by the controller, the state of charge value of the battery to a predetermined second state of charge threshold while performing engine and motor speed control, and determining that the state of charge value of the battery is in a low state of charge when it is determined that the state of charge value of the battery is less than or equal to the second state of charge threshold;

in a low-power state, determining the slip speed of the double-clutch transmission by the controller according to the capacity of the double-clutch transmission and the current torque required by the driver, and determining whether the engine speed reaches the determined slip speed of the double-clutch transmission;

when it is determined that the engine speed reaches the double clutch transmission slip speed, an engine clutch between the engine and the motor is controlled to be in a locked state by the controller and the double clutch transmission clutch is slip-controlled to operate the motor to generate electric power using the remaining engine power remaining after driving the vehicle, so that the battery is charged by the motor.

7. The method of claim 6, further comprising:

a forced engine charging operation of charging the battery by operating the hybrid starter generator with engine power by the controller when it is determined that the engine clutch is in the disengaged state before the engine speed reaches the dual clutch transmission slip speed.

8. The method of claim 7, wherein in a forced engine charging operation, the controller is configured to engage a dual clutch transmission clutch and drive the electric machine such that the vehicle travels due to electric machine power.

9. The method of claim 1, wherein when it is determined that the vehicle is in an uphill drive state, the controller is configured to determine whether a manual shift mode is currently selected, and when it is determined that the manual shift mode is not selected, the controller is configured to: high torque control is performed 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 demand torque.

10. The method of claim 9, wherein during the high torque control of the engine, the controller is configured to control engine torque at an engine operating point that converges on the Part-Load max.

11. The method of claim 9, wherein when it is determined that the manual shift mode is selected, the controller is configured to compare the state of charge value of the battery to a predetermined third state of charge threshold, and when it is determined that the state of charge value of the battery is less than or equal to the third state of charge threshold, the controller is configured to control an engine clutch between the engine and the electric machine to a locked state and control a dual clutch transmission clutch to slip, thereby operating the electric machine to generate electric power using remaining engine power remaining after driving the vehicle such that the battery is charged by the electric machine.

12. The method of claim 11, wherein, when it is determined that the discharged amount of the battery during the predetermined time becomes greater than or equal to a predetermined third discharged amount reference value while the battery is being charged by the motor, the controller is configured to execute a ramp mode to release the manual shift mode.

13. The method of claim 2, wherein,

the predetermined discharge amount reference value comprises a second discharge amount reference value;

upon determining a running state of the vehicle, in response to the vehicle being determined to be in a low-discharge uphill running state in which a discharge amount of the battery during a predetermined time is greater than or equal to a predetermined first discharge amount reference value and less than the second discharge amount reference value, the controller is configured to determine whether a manual shift mode is currently selected, and when it is determined that the manual shift mode is not selected, the controller is configured to: high torque control is performed 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 demand torque.

14. The method of claim 13, wherein during the high torque control of the engine, the controller is configured to control engine torque at an engine operating point that converges on the Part-Load max.

15. The method of claim 2, wherein,

the predetermined discharge amount reference value comprises a second discharge amount reference value;

upon determining a driving state of the vehicle, in response to the vehicle being determined to be in a low-discharge uphill driving state in which a discharge amount of the battery for 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 the manual shift mode is selected, the controller is configured to compare a state of charge value of the battery with a predetermined third state of charge threshold value, and when it is determined that the state of charge value of the battery is less than the third state of charge threshold value, the controller is configured to control an engine clutch between the engine and the motor to be in a locked state and control a dual clutch transmission clutch to slip, thereby operating the motor to generate electric power using remaining engine power remaining after driving the vehicle, so that the battery is charged by the motor.

16. The method of claim 15, wherein, when it is determined that the discharged amount of the battery during the predetermined time becomes greater than or equal to a predetermined third discharged amount reference value while the battery is being charged by the motor, the controller is configured to execute a ramp mode to release the manual shift mode.

17. The method of claim 1, wherein the controller comprises:

a processor; and

a non-volatile storage medium having recorded thereon a program for executing the method according to claim 1 and being executed by a processor.

18. A non-transitory computer readable medium having recorded thereon a program for executing the method according to claim 1.

Technical Field

The present invention relates to a method of controlling uphill driving of a vehicle. More particularly, the present invention relates to a method of controlling uphill driving of a vehicle, which is configured to always ensure a proper state of charge (SOC) value of a battery by minimizing battery discharge during uphill driving, and to minimize energy consumption in an acceleration section.

Background

In recent years, as a transmission of a vehicle, application of a Dual Clutch Transmission (DCT) configured to realize a quick shift without power interruption is increasing.

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

In this case, a Dual Clutch Transmission (DCT) is configured such that power of a vehicle drive source can be transmitted to one of the two input shafts, and the two input shafts, the two output shafts, and the two clutches are configured to realize shift stages of odd-numbered gears and even-numbered gears in the series of gears.

Furthermore, the sequence of gears and the substantial gear shift are performed by torque shifting, in which one of the two clutches is engaged and the other clutch is released, so that a phenomenon of torque drop during the gear shift can be prevented and the gear shift can be completed.

In recent years, a Dual Clutch Transmission (DCT) is also installed in an electrically-powered vehicle such as a Hybrid Electric Vehicle (HEV) and a plug-in HEV (phev), and the application of the DCT is gradually expanding in order to improve fuel efficiency of the electrically-powered vehicle and provide more driving pleasure to a driver.

In the case of the HEV and PHEV provided with the DCT, since there are two clutches in addition to the conventional hybrid clutch, the degree of freedom of control is high.

However, due to the disadvantage of HEV and PHEV provided with a Transmission Mounted Electric Device (TMED) hybrid system, that is, the state of charge (SOC) value of a battery during uphill driving, is decreased, an alternative solution is required to solve the problem of the decrease in driving ability and fuel efficiency.

To describe in more detail, in the TMED hybrid system, when a minimum speed (RPM) at which an engine is normally controlled in an initial stage of vehicle acceleration is referred to as an engageable speed, the vehicle is accelerated at a speed greater than or equal to the engageable speed by engaging (locking) an engine clutch and then using engine power. However, at speeds below the engageable speed, there is a battery discharge region as shown in fig. 1, since the motor is responsible for vehicle acceleration.

Therefore, when the uphill drive requiring a large amount of power consumption of the battery is continuously performed, a decrease in the SOC may occur due to continuous battery discharge.

The TMED hybrid system utilizes engine power by slip controlling the engine clutch when the vehicle is accelerating in a state where the SOC value of the battery is low. However, since the general engine clutch does not have sufficient slip capability required as an acceleration clutch, and in the TMED hybrid system provided with the DCT, there is a case where a lightweight material configured to open/close (engage/disengage) only the engine clutch is utilized, so that there is a limitation in the use of the engine clutch.

Further, when the driver operates the gear shift in the manual shift mode, the degree of freedom of control is reduced, so that there is a limitation in protection of the SOC value of the battery, and the possibility of occurrence of a problem increases.

For example, as described with reference to fig. 2, when the vehicle is running on an uphill road in the second gear, since the engine torque (150Nm) is greater than the driver required torque (100Nm), the motor operates as a generator using the remaining engine torque (50Nm) (in this case, the motor torque is negative torque of-50 Nm), so that the battery can be charged.

However, when the driver intentionally shifts to the third gear on an uphill road using the manual shift mode and then drives the vehicle, since the engine torque (80Nm) is smaller than the driver required torque (100Nm), the motor torque (20Nm) may be additionally generated to meet the driver required torque. In this case, the motor consumes electric power, so that the battery is discharged.

When this situation continues, the SOC value of the battery may drop below the limit level due to excessive discharge of the battery, and a situation in which the vehicle cannot travel may occur.

Further, since the engine clutch slips at a low speed (low RPM) in the manual shift mode during the low-speed uphill driving, there may occur problems of excessive battery discharge and degradation of SOC and driving capability.

In the manual shift mode, the shift timing cannot be predicted, and therefore, the shift feeling cannot be handled, regenerative braking is restricted, and charging is hardly performed during downhill running, which causes a drop in fuel efficiency.

The information included in this background section of the invention is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information constitutes prior art already known to a person skilled in the art.

Disclosure of Invention

Various aspects of the present invention are directed to provide a method of controlling uphill driving of a vehicle, which is configured to secure a state of charge (SOC) value of a battery by minimizing battery discharge, and to minimize energy consumption in an acceleration region.

In another aspect, aspects of the present invention provide a method of controlling uphill driving of a vehicle, which is configured to minimize a decrease in driving capability and fuel efficiency due to discharge of a battery and a decrease in SOC during the uphill driving of the vehicle.

Objects of the present invention are not limited to the above objects, and other objects of the present invention, which are not mentioned, may be understood by the following description, and will also be clearly understood by embodiments of the present invention. Further, the objects of the invention can be achieved by the methods described in the appended claims and combinations thereof.

In various exemplary embodiments of the present invention, aspects of the present invention provide a method of controlling uphill driving of a hybrid vehicle provided with a Dual Clutch Transmission (DCT), the method including: determining, by the controller, a driving state of the vehicle based on the information collected from the vehicle; performing, by a controller, high torque control on an engine of a vehicle by increasing the engine torque to control the engine at a predetermined high torque engine operating point and decreasing a motor torque of a motor in the vehicle to meet a driver required torque when the vehicle is determined to be in an uphill driving state; and comparing, by the controller, a state of charge (SOC) value of the battery with a set first SOC threshold value during the execution of the high torque control on the engine, and executing 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.

Further, the method of controlling uphill driving of a vehicle may further include: comparing, by the controller, the SOC value of the battery with a set second SOC threshold value while the engine and motor speed control is being executed, and determining that the SOC value of the battery is in a low SOC state when the SOC value of the battery is less than or equal to the second SOC threshold value; determining, by the controller, a DCT slip-able speed based on a capacity of the DCT and a current driver-demanded torque in a low SOC state, and determining whether an engine speed reaches the determined DCT slip-able speed; when the engine speed reaches a DCT slip-able speed, an engine clutch between the engine and the motor is controlled by the controller to be in a locked state and the DCT clutch is slip-controlled, thereby operating the motor to generate electric power using remaining engine power remaining after driving the vehicle, so that the battery is charged by the motor.

Further, the method of controlling uphill driving of a vehicle may further include: before the engine speed reaches the DCT slip-able speed, the battery is forcibly engine-charged by the controller by operating a Hybrid Starter Generator (HSG) to generate electric power using engine power when the engine clutch is in the disengaged state.

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

In still another exemplary embodiment of the present invention, when the manual shift mode is selected, the controller may compare the SOC value of the battery with a set third SOC threshold value, and when the SOC value of the battery is less than or equal to the third SOC threshold value, the controller may be configured to control an engine clutch between the engine and the motor to be in a locked state, and may control the DCT clutch to slip, thereby operating the motor to generate electric power using remaining engine power remaining after driving the vehicle, so that the battery may be charged by the motor.

Further, in still another exemplary embodiment of the present invention, the controller may perform a ramp mode to forcibly release the manual shift mode when a discharge amount of the battery during the set time becomes greater than a predetermined third discharge amount reference value while the battery is charged by the motor.

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

It should be understood that the term "vehicle" or "vehicular" or other similar terms as used herein generally includes motor vehicles, such as passenger vehicles including Sport Utility Vehicles (SUVs), buses, vans, various commercial vehicles, watercraft including various boats, ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen powered vehicles, and other alternative fuel vehicles (e.g., fuels derived from non-petroleum sources). As referred to herein, a hybrid vehicle is a vehicle having two or more power sources, such as both gasoline-powered and electric-powered vehicles.

The above and other features of the present invention are discussed below.

The method and apparatus of the present invention have other features and advantages which will be apparent from or are set forth in detail in the accompanying drawings and the following detailed description, which are incorporated herein, and which together serve to explain certain principles of the invention.

Drawings

Fig. 1 is a graph showing a battery discharge region that may occur when a hybrid vehicle is running on an uphill road;

FIG. 2 is a schematic diagram illustrating the discharge of a battery by a motor that may occur when a hybrid vehicle is traveling on an uphill road and shifting gears;

fig. 3 is a schematic diagram showing a configuration of a powertrain of a vehicle configured to apply a method of controlling uphill driving according to various exemplary embodiments of the present invention;

FIG. 4 is a block diagram illustrating a controller and hardware configured to perform uphill drive control of a vehicle according to various exemplary embodiments of the invention;

FIG. 5 is a flowchart illustrating a method of controlling uphill driving of a vehicle according to various exemplary embodiments of the present invention; and

fig. 6 and 7 are schematic views illustrating an uphill driving control state of a vehicle according to various exemplary embodiments of the present invention.

It is to be understood that the appended drawings are not necessarily to scale, showing a somewhat simplified representation of various illustrative features illustrative of the basic principles of the invention. The specific design features of the invention included herein, including, for example, specific dimensions, orientations, locations, and shapes, will be determined in part by the particular intended application and environment of use.

In the drawings, like or equivalent parts of the invention are designated by reference numerals throughout the several views of the drawings.

Detailed Description

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

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

Throughout the specification, when an element is referred to as "comprising" or "includes" a component, it means that the component may further include other components, and other components are not excluded unless otherwise specified.

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

Further, various aspects of the present invention provide a method of controlling uphill driving of a vehicle, which is configured to minimize a decrease in driving capability and fuel efficiency due to discharge of a battery and a decrease in SOC during the uphill driving of the vehicle.

The present invention is applicable to an electric vehicle driven by a motor. The present invention is applicable to a hybrid vehicle driven by an engine and a motor, and is applicable to a hybrid vehicle provided with a Dual Clutch Transmission (DCT) as a transmission.

Fig. 3 is a schematic diagram showing a configuration of a power train of a hybrid vehicle configured to apply a method of controlling uphill driving according to various exemplary embodiments of the present invention, which shows a transmission-mounted electric device (TMED) hybrid system of a vehicle provided with a DCT 14.

As shown, the TMED hybrid system includes: an engine 11 and a motor 13 as driving means for driving the vehicle, an engine clutch 12 installed between the engine 11 and the motor 13, and a DCT 14 connected to an output side of the motor 13.

Further, the vehicle includes a Hybrid Starter and Generator (HSG) 16, an inverter 17, and a battery 18; the HSG16 is a motor configured to start the engine 11; the inverter 17 is used for driving and controlling the motor 13 and the HSG 16; the battery 18 is connected to the motor 13 and the HSG16 chargeable and dischargeable via an inverter 17 as a power source (power source) of the motor 13 and the HSG 16.

In the TMED hybrid system, an electric motor 13 for driving the vehicle is power-transmitting connected to drive wheels 15 via a DCT 14. Accordingly, the motor 13 may be driven with the power of the battery 18 to provide the rotational force to the driving wheels 15, and conversely, the rotational force of the driving wheels 15 may be received to generate the power, thereby charging the battery 18.

The engine clutch 12 performs a locking operation or a releasing operation to be connected or disconnected in a power transmission manner between the engine 11 and the motor 13, and the DCT 14 changes the speed of the rotational power transmitted from the motor 13 to transmit the rotational power to the drive wheels 15 through the drive shaft.

To drive the motor 13 and the HSG16, the inverter 17 is provided to convert a Direct Current (DC) current of the battery 18 into a three-phase Alternating Current (AC) current to apply the three-phase AC current to the motor 13 and the HSG16, and the battery 18 supplies power or is charged during a power generating operation of the motor 13 and the HSG16 during driving of the motor 13 and the HSG 16.

Meanwhile, the present invention includes a control process of protecting the SOC value of the battery 18 during the uphill drive. To execute the control process of protecting the SOC value of the battery 18, the controller 10: determining a current situation of the vehicle driving on an uphill slope; in the case where the vehicle is currently running on a high-load uphill, executing engine high-torque control to raise (increase) the engine torque; when the battery 18 is over-discharged, the SOC value of the battery 18 is protected by speed control for the engine 11 and the motor 13.

Here, the battery 18 is a battery provided in the vehicle, which supplies drive power (or discharges) to the motor 13, and receives and stores power (or charges) generated by the motor 13 when the motor 13 operates as a generator. The SOC value (%) of the battery represents the remaining capacity of the battery 18.

Further, the SOC value of the protection battery 18 represents a series of processes of maintaining and managing the SOC value of the battery 18 so as not to fall below a predetermined limit value.

In the hybrid system shown in fig. 3, when the power of the engine 11 is transmitted to the motor 13 via the engine clutch 12 in the driving state of the engine 11 and the locked state of the engine clutch 12, the motor 13 may be operated as a generator due to the power of the engine 11 to charge the battery 18 ("motor charge").

Further, the present invention includes an uphill drive control process when the battery 18 enters a low SOC. During the uphill travel control, the forced charging control for the engine 11 is executed before the speed (RPM) of the engine 11 reaches the slip-able speed of the DCT 14.

Here, the forced charge control for the engine 11 means: control for executing a series of processes in which the engine 11 is driven to cause the HSG16 to operate as a generator using the engine power, so that the battery 18 is charged by the HSG 16.

Further, during the uphill drive control when the battery 18 enters the low SOC, after the speed (RPM) of the engine 11 reaches a slip-able speed of the DCT 14, the clutches 14a and 14b (hereinafter referred to as "DCT clutches") in the DCT 14 are slip-able, so that the engine clutch 12 is locked up and the DCT clutches 14a and 14b are slip-controlled (one of the DCT clutches 14a and 14b is slip-controlled). Thus, a part of the engine power is transmitted to the drive wheels 15 to drive the vehicle, and the motor 13 operates as a generator using the remaining engine power to charge the battery 18.

Further, the invention includes a control process for ensuring the SOC value of the battery 18 in the uphill-traveling manual shift mode. During such control, the DCT clutches 14a and 14b are slip-controlled, and in the event of an excessive discharge amount of the battery 18, a ramp mode is executed to forcibly release the manual shift mode.

Methods of controlling uphill driving of a vehicle according to various exemplary embodiments of the present invention may be performed by a controller in the vehicle. Hereinafter, the present invention will be described in more detail with respect to each detailed process performed by the controller.

FIG. 4 is a block diagram illustrating a controller and hardware configured to perform uphill drive control of a vehicle according to various exemplary embodiments of the invention; fig. 5 is a flowchart illustrating a method of controlling uphill driving of a vehicle according to various exemplary embodiments of the present invention.

Control process for protecting SOC value of battery during uphill driving

First, the controller 10 determines the current running state of the vehicle based on information collected from the vehicle. The controller 10 determines whether the vehicle is currently performing high-discharge uphill running or low-discharge uphill running.

In this case, the controller 10 compares the discharge amount Δ SOC value of the battery 18 during the set time 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 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 may determine that the vehicle is in a low-discharge uphill running condition.

Further, when the discharge amount of the battery 18 during the set time is greater than or equal to a predetermined second discharge amount reference value β, the controller 10 may determine that the vehicle is in a high-discharge uphill running condition.

Here, the discharge amount of the battery 18 indicates the SOC variation Δ SOC of the battery 18. The discharge amount of the battery 18 indicates the SOC variation Δ SOC of the battery 18 in the case of discharge, that is, the decrease amount of the SOC value of the battery 18.

Further, the discharge amount of the battery 18 during the set time may be the total discharge amount of the battery 18 during the set time or an average value of the discharge amounts of the battery 18 (discharge power of the battery 18) during the set time. In this case, the average value may be an average value obtained by a moving average method.

The set time is a time sufficient to determine the discharge condition of the battery 18 and is set in the controller 10. The first discharged-amount reference value α may be set to a value corresponding to an amount of SOC variation upon entry from the center SOC to a predetermined low SOC (a second SOC threshold value, which will be described below), and the second discharged-amount reference value β may be set to a value corresponding to an amount of SOC variation from the center SOC to a predetermined idle charge entry SOC.

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

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

The set time, the first discharged amount reference value α, and the second discharged amount reference value β are values that are preset in the controller 10, and are determined through a preliminary test and evaluation process to be used after being input and stored in the controller 10. The above values are merely examples, the present invention is not limited thereto, and the above values may be variously changed.

Next, when the controller 10 determines that the situation is the high-discharge uphill running, the controller 10 executes the high torque control on the engine 11 (step S13).

During the high torque control, the driver required torque is satisfied by the engine torque and the motor torque. The engine torque is increased to perform the high torque control at a predetermined high torque engine operating point, and at the same time, the motor torque is decreased to meet the driver demand torque.

In this case, the engine torque control is executed to guide the high-torque engine operating point to converge on the preset Part-Load max. Therefore, the engine 11 outputs a high level of torque, so that it is possible to minimize a decrease in the SOC value of the battery 18 due to the driving of the motor 13.

Part-Load max. is defined as: maximum torque or maximum power when the engine is controlled with Lambda (λ)1(═ actual air-fuel ratio/engine stoichiometric air-fuel ratio). That is, the region higher than Part-Load max is when the engine is controlled to λ <1, and the region equal to or smaller than Part-Load max is when the engine can be controlled to λ 1.0.

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

Here, the first SOC threshold value γ may be set to an idle charge entry SOC value.

In various exemplary embodiments of the present invention, the engine and motor speed control is executed with a limit in a mode in which it is necessary to protect the SOC value of the battery 18 as much as possible. In performing engine and motor speed control, the controller 10 controls the engine clutch 12 in a locked (engaged) state and controls the DCT clutches 14a and 14b in a slipping state.

Further, when the process of performing the engine and motor speed control is entered, the controller 10 determines the target speed of the engine 11 as a 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 as the determined target speed in the process of performing the engine and motor speed control.

In this case, since the engine clutch 12 is in the locked state, the speed of the motor 13 is maintained to be equal to the speed of the engine 11, and when the vehicle travels in the slipping state of the DCT clutches 14a and 14b, the high speed of the engine 11 is maintained, so that the engine power can be sufficiently secured to minimize the release of the SOC value of the battery 18.

That is, the control state is summarized as follows.

An engine clutch: locking device

A DCT clutch: slippage

Engine speed-motor speed-DCT output speed + a

Here, the DCT output speed may be obtained from signals of wheel speed sensors installed in the driving wheels 15, and a may be a speed value determined according to the DCT clutch capacity, and may be predetermined by a maximum speed difference between the transmission input speed and the transmission output speed according to the DCT clutch capacity.

Meanwhile, during the engine and motor speed control, the controller 10 compares the SOC value of the battery 18 with a preset second SOC threshold value δ (step S16). In this case, when the SOC value of the battery 18 is less than or equal to the second SOC threshold value δ, the controller 10 determines to enter the low SOC state to execute a predetermined uphill drive control process.

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

2) Uphill drive control process when entering low SOC

When the controller 10 determines that the low SOC state of the battery 18 is entered, the controller 10 determines the DCT slippable speed at the current driver demand torque according to the DCT capacity, and the DCT slippable speed can be determined by the following equation 1.

[ equation 1]

DCT slip speed-maximum DCT slip speed difference-minimum engine speed

Here, the minimum engine speed is a speed (for example, 1000rpm) predetermined according to the engine 11 and set in the controller 10, and the maximum DCT slip speed difference may be determined by the following equation 2.

[ equation 2]

Maximum DCT slip speed differential [ DCT capacity (kW) -power demand (kW) ]/driver torque demand (Nm)

Here, the DCT capacity is a value preset in the controller 10, and may be referred to as a DCT clutch capacity. However, since there are two clutches in the DCT 14, the DCT capacity may vary depending on which clutch is being used.

Further, the required power is a value calculated according to the acceleration intention of the driver (for example, an Accelerator Position Sensor (APS) signal value), and the general vehicle is controlled by determining the required power according to the acceleration intention of the driver in the general vehicle.

As described above, when the DCT slippable speed is determined, the controller 10 compares the current engine speed with the DCT slippable speed to determine whether the engine speed reaches the DCT slippable speed (step S17).

Here, the DCT clutches 14a and 14b cannot slip until the engine speed reaches the DCT slip-able speed. Therefore, as shown in fig. 6, the controller 10 disengages the engine clutch 12, and then executes forced engine charging control (step S18).

In this case, the controller 10 operates the HSG16 to generate electric power as engine power, charges the battery 18 with the generated electric power of the HSG16, and at the same time, immediately drives the motor 13, thereby minimizing the loss of charge and discharge.

Further, in a state where the DCT clutch 14a is engaged, the controller 10 causes the motor power to be transmitted to the drive wheels 15, so that the vehicle can run using the motor power.

Further, the DCT clutches 14a and 14b are slidable after the engine speed reaches the DCT slidable speed. Therefore, as shown in fig. 7, the controller 10 controls the engine clutch 12 to be in the lock-up state, and controls the DCT clutch 14a to slip (step S19).

In this case, a part of the engine power is transmitted to the driving wheels 15 so that the vehicle can run, and the remaining energy (i.e., the remaining engine power) can operate the motor 13 to generate electric power so that the battery 18 can be charged with the electric power generated by the motor 13.

3) Control procedure for ensuring SOC value of battery in uphill driving manual shift mode

Meanwhile, when the controller 10 determines that the vehicle is in the 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 is greater than or equal to the first discharge amount reference value α and less than the second discharge amount reference value β, the controller 10 determines whether the manual shift mode is currently selected (step S20).

Here, when the manual shift mode is not selected, in step S25, the high torque control is executed for the engine 11 in the same manner as in step S13.

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

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

Here, the third SOC threshold value epsilon may be set to a typical low SOC entry determination reference value, and when the capacity of the battery 18 is less than a normal level, the third SOC threshold value epsilon may be set to a value greater than or equal to the typical low SOC entry determination reference value.

The third SOC threshold value epsilon may be equal to or different from the second SOC threshold value delta described above. When the third SOC threshold value e is different from the second SOC threshold value δ, the third SOC threshold value e may be greater than or equal to the second SOC threshold value δ.

As described above, in the low SOC state where the current SOC value of the battery 18 is less than or equal to the third SOC threshold value epsilon, the shift is not arbitrarily performed and the shift position required by the driver is maintained. In this case, as shown in fig. 7, in a state where the engine clutch 12 is locked, the controller 10 controls the DCT clutch 14a to slip, and thus a part of the engine power is transmitted to the drive wheels 15 so that the vehicle can run. Meanwhile, the controller 10 operates the motor 13 to generate electric power using the remaining energy (i.e., the remaining engine power), so that the battery 18 may be charged using the electric power generated by the motor 13.

As described above, while slip-controlling the DCT clutch, the controller 10 compares the discharge amount Δ SOC of the battery 18 during the set time with the preset third discharge amount reference value ζ (step S23). When the discharge amount Δ SOC of the battery 18 during the set time becomes greater than the third discharge amount reference value ζ, the controller 10 executes the ramp mode (step S24).

Here, the discharge amount Δ SOC of the battery 18 during the set time may be defined to be equal to the discharge amount of the battery 18 during the set time in steps S11 and S12.

Further, the third discharge amount reference value ζ may be the same value as one of the first discharge amount reference value α and the second discharge amount reference value β. Alternatively, the third discharge amount reference value ζ may be different from both the first discharge amount reference value α and the second discharge amount reference value β.

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

Further, in the state where the hill mode is executed, even if the driver switches the shift mode to the manual shift mode, the controller 10 forcibly releases the manual shift mode, and executes the shift control according to the shift map.

In this case, the controller 10 may be configured to notify the driver through the notification portion: the manual shift mode is forcibly released. For example, the controller 10 displays a release message, for example, "release the manual shift mode due to over-discharge of the battery" on the cluster board to notify the driver of the current situation.

In the above description, although it has been described that the case where the vehicle is currently determined to be in the high-discharge uphill drive according to the discharge amount of the battery 18 during the set time and then the high-torque control is executed on the engine 11, or the case where the vehicle is currently determined to be in the low-discharge uphill drive according to the discharge amount of the battery 18 during the set time and, at the same time, the current state is determined to be the manual shift mode, the high-torque control in step S13 may be set to be executed on the engine 11 when the vehicle is in the uphill drive and the current mode is not the manual shift mode, without being classified in detail.

In this case, as described above, steps S14 to S19 may be performed after step S13.

Further, in this case, the controller 10 may be configured to execute steps S21 through S24 when the vehicle is in an uphill driving condition and in a manual shift mode.

Further, the controller 10 may determine whether the vehicle performs uphill traveling according to gradient information collected from the vehicle about the current traveling road. Information on the gradient (inclination) of the current traveling road may be acquired from signals of sensors in the vehicle.

Here, the sensor may be a longitudinal acceleration sensor. While the vehicle is running, gradient information about the current running road may be acquired using a signal output from the longitudinal acceleration sensor.

The method and process of acquiring gradient information from the signal of the longitudinal acceleration sensor are well known to those skilled in the art, and thus, a detailed description thereof will be omitted herein.

As described above, the method of controlling uphill driving according to various exemplary embodiments of the present invention may be applied to a hybrid vehicle provided with a DCT, so that the SOC value of a battery during uphill driving can be sufficiently protected to minimize full load entry, and also an idle charge region can be reduced to improve fuel efficiency of the vehicle.

Further, in the case of low SOC uphill travel, it is possible to preferentially perform protection of the SOC value of the battery and minimize a factor of deterioration of the driving capability (e.g., excessive engine penetration sound, occurrence of a shock due to low range slip control, etc.), so that the marketability of the vehicle can be significantly improved.

As described above, based on the method of controlling uphill driving of a vehicle according to various exemplary embodiments of the present invention, it is possible to minimize discharge of a battery to ensure a state of charge (SOC) value of the battery and to minimize energy consumption in an acceleration region. Therefore, the fuel efficiency of the vehicle can be improved, and the reduction of the driving ability and the fuel efficiency due to the discharge and the reduction of the SOC value of the battery can be minimized.

Further, the term "controller" means a hardware device that includes a memory and a processor configured to perform one or more steps that are interpreted as an algorithmic structure. The memory stores algorithm steps, and the processor executes the algorithm steps to perform one or more processes of the method according to various exemplary embodiments of the present invention. The controller according to an exemplary embodiment of the present invention may be implemented by a non-volatile memory configured to store an algorithm for controlling operations of various components of a vehicle or data on software commands for executing the algorithm, and a processor configured to perform the above operations using the data stored in the memory. The memory and the processor may be separate chips. Alternatively, the memory and the processor may be integrated in a single chip. The processor may be implemented as one or more processors.

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

The foregoing invention can also be embodied as computer readable codes on a computer readable recording medium. The computer readable recording medium is any data storage device that can store data which can be thereafter read by a computer system. Examples of the computer-readable recording medium include a Hard Disk Drive (HDD), a Solid State Disk (SSD), a Silicon Disk Drive (SDD), a Read Only Memory (ROM), a Random Access Memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like, and are implemented as a carrier wave (e.g., transmission through the internet).

For convenience in explanation and accurate definition in the appended claims, the terms "upper", "lower", "inner", "outer", "upper", "lower", "upward", "downward", "front", "back", "rear", "inner", "outer", "inward", "outward", "inner", "outer", "forward", "rearward" are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures. It will be further understood that the term "coupled," or derivatives thereof, means both directly and indirectly coupled.

Furthermore, the term "fixedly connected" means that the fixedly connected components always rotate at the same speed. Further, the term "selectively connectable" means that the selectively connectable members rotate apart when they are not engaged with each other, rotate at the same speed when they are engaged with each other, and are stationary when at least one of the selectively connectable members is a stationary member and the remaining selectively connectable members are engaged to the stationary member.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and its practical application to enable others skilled in the art to make and use various exemplary embodiments of the invention and various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the following claims and their equivalents.