Hybrid vehicle and control method thereof

Abstract

This invention relates to a hybrid vehicle and its control method, wherein the hybrid vehicle, which uses an engine and an electric motor as power sources, includes: an input terminal configured to receive a user's selection of a terrain mode; a hybrid starter generator connected to the engine and configured to function as a starter motor to start the engine, and to function as a generator for performing idle charging when the engine is started; a battery electrically connected to the hybrid starter generator; and a controller configured to perform idle charging using the hybrid starter generator when the battery's SOC is less than or equal to a first SOC by starting the engine, wherein the controller is configured to adjust the battery's SOC to perform idle charging based on a second SOC greater than the first SOC when entering a terrain mode.

Description

Technical Field

[0001] This invention relates to a hybrid vehicle and its control method, and more specifically to a hybrid vehicle and its control method for managing the state of charge (SOC) of a battery in terrain mode. Background Technology

[0002] In recent years, considering various usage aspects, consumers have shown a strong preference for Sport Utility Vehicles (SUVs). Terrain Mode, as one of the main functions of SUVs, allows for appropriate driving by distributing drive force appropriately in off-road conditions such as sand, mud, and snow. On the other hand, when an SUV operates in hybrid mode, unlike gasoline or diesel vehicles, battery performance is affected by its state of charge. Therefore, when a hybrid vehicle is driven in Terrain Mode, the battery's SOC needs to be managed differently than on regular roads. Summary of the Invention

[0003] One aspect of the present invention provides a hybrid vehicle and a control method thereof capable of optimizing battery SOC in terrain modes. According to one aspect of the invention, a hybrid vehicle using an engine and an electric motor as power sources includes: an input configured to receive a user's selection of a terrain mode; a hybrid starter generator (HSG) connected to the engine to function as a starter motor to start the engine, and configured to function as a generator for performing idle charging when the engine is started; a battery electrically connected to the HSG; and a controller configured to perform idle charging using the HSG when the battery SOC is less than or equal to a first SOC by starting the engine, the controller being configured to adjust the battery SOC to perform idle charging based on a second SOC greater than the first SOC when entering a terrain mode.

[0004] The controller is configured to adjust the battery's state of charge (SOC) to maintain a second SOC when entering terrain mode. The hybrid vehicle also includes an accelerator pedal detector configured to detect the amount of displacement of the accelerator pedal and transmit this displacement to the controller, which is configured to enter electric vehicle (EV) drive mode when no displacement is detected, enter hybrid electric vehicle (HEV) drive mode when displacement is detected, and enter HEV drive mode even when no displacement is detected when entering terrain mode.

[0005] The controller is configured to: when entering terrain mode, adjust the battery's SOC to maintain it at a second SOC by performing idle charging based on a second SOC in HEV drive mode. The hybrid vehicle also includes: a speed detector configured to detect vehicle speed and transmit the speed to the controller; and the controller is configured to: enter EV drive mode from a stationary state until a first vehicle speed is reached, and enter HEV drive mode from a stationary state when entering terrain mode.

[0006] The controller is configured to: upon entering terrain mode, adjust the battery's SOC to maintain it at the second SOC by performing idle charging based on the second SOC in HEV drive mode. The controller is configured to: in terrain mode, when the battery's SOC is equal to or greater than the second SOC, enter EV drive mode from the standstill of the hybrid vehicle until the first vehicle speed is reached. The controller is configured to: when entering terrain mode, adjust the engine's drive point upwards.

[0007] The hybrid vehicle further includes: a longitudinal acceleration detector configured to detect longitudinal acceleration sensing values ​​to calculate road gradient and transmit the road gradient to a controller, and the controller configured to: in response to determining that the road gradient is an uphill gradient, adjust the magnitude of a second SOC proportional to the gradient in terrain mode. The hybrid vehicle also includes: an accelerator pedal detector configured to detect the amount of displacement of the accelerator pedal and transmit the amount of displacement of the accelerator pedal to the controller, and the controller configured to: in terrain mode, when no displacement is detected, detect the amount of decrease in wheel rotation speed, determine a load level based on the amount of decrease, and adjust the magnitude of the battery SOC proportional to the load level, and the load level is proportional to the gradient.

[0008] According to another aspect of the present invention, a control method for a hybrid vehicle using an engine and an electric motor as power sources includes the following steps: receiving a user's selection of a terrain mode; performing idle charging by starting the engine and utilizing the HSG when the battery's SOC is less than or equal to a first SOC; and when entering the terrain mode, adjusting the battery's SOC based on a second SOC greater than the first SOC to perform idle charging. The step of performing idle charging includes: adjusting the battery's SOC to maintain it at the second SOC when entering the terrain mode.

[0009] The method further includes the following steps: detecting the displacement of the accelerator pedal and transmitting the displacement of the accelerator pedal to the controller; entering EV drive mode when no displacement is detected, entering HEV drive mode when displacement is detected, and entering HEV drive mode even when no displacement is detected when entering terrain mode. The method further includes the following step: when entering terrain mode, adjusting the battery's SOC to maintain it at a second SOC by performing idle charging based on a second SOC in HEV drive mode.

[0010] The method further includes the following steps: detecting the vehicle speed and transmitting the vehicle speed to the controller; and entering EV drive mode while the hybrid vehicle is stationary until a first vehicle speed is reached, and entering HEV drive mode from the stationary state when entering terrain mode. The method also includes the following step: when entering terrain mode, adjusting the battery's SOC to maintain it at a second SOC by performing idle charging based on a second SOC in HEV drive mode.

[0011] The method further includes the following steps: in terrain mode, when the battery's SOC is equal to or greater than a second SOC, entering EV drive mode while the hybrid vehicle is stationary until a first vehicle speed is reached. Additionally, the method includes the following steps: when entering terrain mode, adjusting the engine's drive point upwards; detecting longitudinal acceleration sensing values ​​to calculate the road's gradient and transmitting the detected longitudinal acceleration sensing values ​​to the controller; and in response to determining that the road's gradient is uphill, adjusting the magnitude of the second SOC in terrain mode to be proportional to the gradient.

[0012] The method further includes the following steps: detecting the displacement of the accelerator pedal and transmitting the detected displacement to the controller; and in terrain mode, when no displacement is detected, detecting the decrease in wheel rotation speed, determining the load level based on the decrease, and adjusting the battery's state of charge (SOC) to be proportional to the load level. The load level is proportional to the gradient.

[0013] The methods and apparatus of the present invention have other features and advantages, which will be appreciated through the accompanying drawings and appendices incorporated herein by reference. Figure 1 The following detailed description, which illustrates certain principles of the invention, will make them obvious or will be described in more detail. Attached Figure Description

[0014] These and / or other aspects of the invention will become apparent and more readily understood from the following description of exemplary embodiments taken in conjunction with the accompanying drawings, wherein:

[0015] Figure 1 This is a configuration diagram of a vehicle according to an exemplary embodiment;

[0016] Figure 2 This is a control block diagram of a vehicle according to an exemplary embodiment;

[0017] Figure 3 This is a diagram used to explain an example of a terrain pattern according to an exemplary implementation;

[0018] Figure 4 This is a diagram used to explain an example of a terrain pattern according to another exemplary implementation;

[0019] Figure 5 This is a diagram illustrating the upward adjustment of the engine drive point in a terrain mode according to an exemplary embodiment;

[0020] Figure 6 This is a diagram illustrating the process of determining a load level under a terrain pattern according to an exemplary embodiment;

[0021] Figure 7 This is a flowchart of a control method according to an exemplary embodiment. Detailed Implementation

[0022] It should be understood that the terms "vehicle" or "of a vehicle" or other similar terms as used herein generally include conventional motor vehicles, such as passenger vehicles including sport utility vehicles (SUVs), buses, trucks, and various commercial vehicles, water vehicles including various boats and vessels, and aircraft, and include hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other vehicles powered by alternative fuels (e.g., fuels derived from resources other than petroleum). As mentioned herein, a hybrid vehicle is a vehicle having two or more power sources, such as a vehicle powered by both gasoline and electricity.

[0023] Although exemplary embodiments are described as using multiple units to perform exemplary processes, it should be understood that exemplary processes can also be performed by one or more modules. Furthermore, it is understood that the term controller / control unit refers to a hardware device including a memory and a processor, specifically programmed to perform the processes described herein. The memory is configured to store modules, and the processor is specifically configured to execute said modules to perform one or more processes further described below.

[0024] The terminology used herein is for illustrative purposes only and is not intended to limit the invention. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that, when used in this specification, the words “comprising” and / or “including” specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein, the word “and / or” includes any and all combinations of one or more of the associated listed items.

[0025] Unless otherwise specified or obvious from the context, the term "about" as used herein shall be understood to mean within the normal tolerance range in the field, such as within 2 standard deviations of the mean. "About" may be understood to mean within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. All numerical values ​​provided herein are modified by the term "about" unless otherwise clearly understood from the context.

[0026] Detailed reference is now given to various exemplary 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 should be understood that this description 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, variations, equivalents and other embodiments that may be included within the spirit and scope of the invention as defined by the appended claims.

[0027] Throughout the following description, the same reference numerals denote the same elements. This specification does not describe all elements of the embodiments, and there is no overlap in general content or implementation within the field of the invention to which exemplary embodiments of the invention pertain. Terms such as “unit,” “module,” “component,” and “block” can refer to hardware or software. According to an embodiment, multiple “units,” “modules,” “components,” and “blocks” may be implemented as a single component, or a single “unit,” “module,” “component,” and “block” may comprise multiple components.

[0028] It should be understood that when an element is referred to as "connected to" another element, it can be directly or indirectly connected to the other element, wherein indirect connection includes "connection via a wireless communication network". The terms first, second, etc., are used to distinguish one component from another, and components are not limited by the foregoing terms. Unless there is a clearly different meaning in the context, the singular form includes the plural form. The reference numerals used in the operation are for ease of description and are not intended to describe the order of operations, and operations may be performed in different orders unless otherwise stated.

[0029] In the following description, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. Figure 1 This is a configuration diagram of a vehicle according to an exemplary embodiment. Figure 2 This is a control block diagram of a vehicle according to an exemplary embodiment. A hybrid vehicle 1 according to an exemplary embodiment may include: a transmission 10, an electric motor 20, a clutch 30, an engine 40, an inverter 50, a hybrid starter generator (HSG) 60, a battery 70, and a fuel tank 80.

[0030] Clutch 30 can be installed between electric motor 20 and engine 40, and transmission 10 can be connected to the output of electric motor 20. Therefore, the hybrid vehicle 1 according to the exemplary embodiment can employ the TMED (transmission mounted electric device) method, wherein the output of electric motor 20 is directly connected to transmission 10. Inverter 50 can be configured to convert direct current (DC) stored in battery 70 to alternating current (AC) and provide AC to operate electric motor 20. Alternatively, inverter 50 can be configured to convert AC to DC to store energy in battery 70.

[0031] When the battery's State of Charge (SOC) drops below a predetermined standard, the HSG60 can be configured to start the engine 40 and operate the battery 70 to charge it using engine torque. Conversely, when the battery's SOC exceeds a certain level, the HSG60 can be configured to shut off the engine and terminate charging. In this case, idling charging is a method of using the engine to charge the battery 70 to maintain SOC balance when the battery's state of charge drops below a certain level during driving or while stationary.

[0032] The HSG60 can be connected to the engine 40 and used as a starter motor to start the engine 40. When the engine 40 is running, the HSG60 can also function as a generator to perform idle charging. The fuel tank 80 can store liquid fuel such as gasoline or diesel and provide chemical energy to drive the engine 40. The controller 200 can be configured to regulate output torque by integrally operating the components of the hybrid vehicle 1 connected to the network, and to provide HEV mode and EV mode operation by engaging or disengaging the clutch 30.

[0033] According to an exemplary embodiment, the controller 200 can be configured to start / stop the engine 40 based on the displacement of the accelerator pedal, the vehicle speed, the gear position, and the state of charge (SOC) of the battery 70. The controller 200 can also be configured to detect whether the hybrid vehicle 1 is in a stopped state while driving based on the displacement of the accelerator pedal, the vehicle speed, and the gear position. When the vehicle is stopped while driving, the controller 200 performs idle charging using the HSG 60 based on the SOC of the battery 70, and stops idle charging based on the displacement of the accelerator pedal.

[0034] Accelerator pedal detector 110 can be configured to detect the displacement of the accelerator pedal and send the displacement to controller 200 via a network, and vehicle speed detector 120 can be configured to detect vehicle speed and send the vehicle speed to controller 200 via a network. Transmission detector 130 can be configured to detect the current gear position of transmission 10 and send the position to controller 200 via a network. Battery manager 140 can be configured to comprehensively detect information such as the voltage, current, and temperature of battery 70 to manage state of charge (SOC) and send the SOC of battery 70 to controller 200 via a network.

[0035] Additionally, the longitudinal acceleration detector 150 can be configured to detect longitudinal acceleration sensing values ​​and send these values ​​to the controller 200 via a network. The controller 200 can then be configured to calculate the slope of the ground on which the vehicle is located based on the longitudinal acceleration sensing values. The battery manager 140 can be configured to control the charging and discharging voltage of the battery 70 to prevent the battery 70 from having its lifespan shortened due to over-discharging below a threshold voltage or overcharging above a threshold voltage. The battery 70 may include multiple cell units and stores a high voltage for providing drive power to the electric motor 20.

[0036] According to an exemplary embodiment, the controller 200 can be configured to perform idle charging when the state of charge (SOC) of the battery 70 is less than or equal to a first SOC, by starting the engine 40 and utilizing the HSG 60. Here, the first SOC represents the standard for initiating such charging when not in terrain mode. For example, when the SOC has a value greater than the first SOC, the controller 200 can be configured to stop charging and operate the HSG 60 such that the SOC of the battery 70 is maintained at the first SOC. At this time, when entering terrain mode, the controller 200 can be configured to change the first SOC (the standard for initiating idle charging) to a second SOC.

[0037] The controller 200 can be configured to perform idle charging based on a second SOC greater than the first SOC. Therefore, according to this exemplary embodiment, a higher SOC can be maintained in terrain mode, and driving force can be provided by the electric motor 20 with a high response speed when leaving the road. When entering terrain mode, the controller 200 according to the exemplary embodiment can be configured to adjust the SOC of the battery 70 to maintain it at the second SOC. The controller 200 may include: at least one memory 220 storing a program for performing the operations described above and below; and at least one processor 210 for executing the stored program. In the case of multiple memories and processors, the memories and processors may be integrated into a single chip or located in physically separate positions.

[0038] Figure 3 This is a diagram used to explain an example of a terrain pattern according to an exemplary implementation. For example... Figure 3 As shown in the upper part, in the TMED (Transmission Mounted Electric Device) system, the engine is driven and the electric motor's driving force is increased before the engine clutch is engaged. Furthermore, since the engine is not driven when no displacement of the accelerator pedal is detected, the vehicle's driving force depends on the electric motor. At this time, the battery's SOC decreases until the engine clutch engages, thus failing to maintain sufficient SOC.

[0039] In this exemplary embodiment, in terrain mode, the engine clutch is always engaged with the engine at a predetermined vehicle speed or higher, so engine driving force can always be utilized in the start / accelerate state. The controller 200 according to the exemplary embodiment can be configured to receive the displacement of the accelerator pedal from the accelerator pedal detector 110, enter EV drive mode when no displacement is detected, and enter HEV drive mode when a displacement is detected.

[0040] At this time, when entering terrain mode, the controller 200 can be configured to maintain engagement between the clutch 30 and the engine 40 even if no displacement of the accelerator pedal is detected, thereby entering HEV drive mode. Therefore, the hybrid vehicle 1 according to this embodiment can ensure a certain or higher level of SOC by driving the engine 40 even when the driver's accelerator pedal is not input, through idle charging. According to the exemplary embodiment, the controller 200 can be configured to maintain the SOC of the battery 70 at a second SOC by performing idle charging based on a second SOC in HEV drive mode when entering terrain mode. Figure 3 As shown in the lower part, the engine driving force can be maintained even if no displacement of the accelerator pedal is detected, thus ensuring a certain level or higher of SOC.

[0041] Figure 4 This is a diagram used to explain another example of a terrain pattern according to another exemplary implementation. The TMED system initially uses only the electric motor when the vehicle starts, but as the vehicle speed increases, it may include a sink control method using engine power (see [link to diagram]). Figure 4 The upper part), and the launch control method that uses the electric motor and engine from the initial start (see the upper part), and the launch acceleration control method (see the upper part). Figure 4 (Lower part). In particular, when the battery's SOC does not meet a certain level (e.g., low SOC, low temperature, or high temperature) and the motor's power is insufficient, the start-up acceleration control method can be used.

[0042] According to an exemplary embodiment, the controller 200 can be configured to receive vehicle speed from the speed detector 120 and operate the vehicle in a stopped state of the hybrid vehicle 1 until a first vehicle speed is reached, entering EV drive mode. Furthermore, when entering terrain mode, the controller 200 can be configured to operate the vehicle to transition from a stopped state to HEV drive mode. Therefore, idle charging can be performed by starting the engine 40 from the moment the vehicle begins to run, thereby ensuring that the battery 70 has a certain level or higher SOC.

[0043] When entering terrain mode, the controller 200 according to the exemplary embodiment can be configured to perform idle charging based on a second SOC in HEV drive mode. At this time, the controller 200 can be configured to maintain the SOC of the battery 70 at the second SOC. However, to prevent charging the battery 70 beyond its required SOC, the controller 200 according to the exemplary embodiment can be configured to: in terrain mode, when the SOC of the battery 70 is greater than or equal to the second SOC, in the stopped state of the hybrid vehicle 1, enter EV drive mode instead of HEV drive mode until a first vehicle speed is reached.

[0044] Figure 5 This diagram illustrates the upward orientation of the engine drive point in a terrain mode according to an exemplary embodiment. In hybrid vehicles, the engine can be driven at the optimal drive point, where efficiency is maximized under normal driving conditions due to a focus on fuel economy. However, when driving on rough roads in terrain mode, rather than in normal driving conditions, escape performance is more important than fuel economy. In particular, it is necessary to adequately ensure State of Charge (SOC) by increasing the engine's operating range.

[0045] When entering terrain mode, the controller 200 according to the exemplary embodiment can be configured to adjust the drive point of the engine 40 upwards. At this time, the driving force of the electric motor 20 can decrease as the drive point of the engine 40 increases. Therefore, as the driving force of the engine 40 increases, the battery 70 can ensure a higher state of charge (SOC) than currently achieved.

[0046] Figure 6 This is a diagram illustrating the process of determining a load level in a terrain mode according to an exemplary embodiment. The vehicle executing the terrain mode is subjected to a load based on road conditions. At this time, the road condition includes the slope or road state of the road where the vehicle is located (e.g., sand, mud, and snow), and the vehicle performs various controls based on the road level representing the road state. At this time, the battery's SOC consumption increases with the increase in load caused by road conditions.

[0047] Simultaneously, when a vehicle is traveling on an inclined road, a longitudinal acceleration sensor installed on the vehicle can be used to detect the longitudinal acceleration sensing value, and the slope can be calculated by applying the longitudinal acceleration sensing value to a slope function. At this time, the vehicle can estimate the additional load received based on the degree of inclination, and the individual control level can be determined in terrain mode by taking the load received by the vehicle into account.

[0048] However, when a vehicle travels on sand, mud, or snow, unlike on a sloping road, it is difficult to estimate the additional load. Therefore, the road level caused by road conditions can be determined by referring to the estimated load on a sloping road. According to an exemplary embodiment, the controller 200 can be configured to receive longitudinal acceleration sensing values ​​from the longitudinal acceleration detector 150 and calculate the slope of the ground. In response to determining that the ground slope is a back slope, the controller 200 can be configured to adjust the size of the second SOC proportionally to the slope in terrain mode. Figure 6 As shown, the load received by the vehicle can be proportional to the gradient.

[0049] At this time, the load received by the vehicle causes the wheel rotation rate to decrease. Even when the vehicle is off-roading, the same load is generated and the wheel rotation rate decreases as when it is on sloping ground. Figure 6 This illustrates the relationship between the load caused by gradient and the load caused by vehicle speed. During off-road driving, as vehicle speed increases, wheel speed decreases, and the load on the vehicle increases.

[0050] According to an exemplary embodiment, the controller 200 can be configured to receive the displacement of the accelerator pedal from the accelerator pedal detector 110, and detect a decrease in the vehicle's rotational speed and wheel rotational speed. In this case, the controller 200 can be configured to detect a decrease in wheel rotational speed when no displacement is detected, and determine the load level based on this decrease. In terrain mode, the controller 200 can be configured to adjust the magnitude of the second SOC to be proportional to the load level. In this case, the slope of the load level is a proportional relationship, which can be referenced... Figure 6 The proportional relationship shown.

[0051] Figure 7 This is a flowchart of a control method according to an exemplary embodiment. The controller 200 can be configured to receive user input on a terrain mode (701). Specifically, the driver can select a driving mode based on the terrain by inputting an input to a terrain mode switch. In this case, the controller 200 can be configured to perform various controls based on the user-input driving mode. If the controller 200 does not detect user input on a terrain mode, the controller can be configured to perform general control (703).

[0052] When user input for terrain mode is detected, controller 200 can be configured to change a first SOC, which serves as a standard for idle charging, to a second SOC to ensure electrical energy at a level higher than the existing battery SOC (702). At this time, the second SOC indicates a higher energy storage capacity than in the absence of terrain mode, and the second SOC can have various capacities depending on the manufacturer's initial production stage and user settings. Controller 200 can be configured to determine the battery's SOC (704). If the battery's SOC is equal to or less than the second SOC (705), idle charging can be performed to bring the battery's SOC to the second SOC (706). The battery's SOC can be adjusted to maintain the second SOC (707).

[0053] As described above, various exemplary embodiments disclosed have been described with reference to the accompanying drawings. Those skilled in the art will understand that the present invention may be implemented in forms different from the disclosed exemplary embodiments without altering the technical spirit or essential characteristics of the invention. The disclosed exemplary embodiments are exemplary and should not be construed as restrictive.

[0054] On the other hand, the disclosed embodiments can be implemented in the form of a recording medium for storing instructions that can be executed by a computer. The instructions can be stored as program code, and when executed by a processor, a program module can be generated to perform the operations of the disclosed embodiments. The recording medium can be implemented as a computer-readable recording medium.

[0055] Computer-readable recording media include all types of recording media in which instructions can be decoded by a computer. Examples include read-only memory (ROM), random access memory (RAM), magnetic tape, hard disk, flash memory, optical data storage devices, etc.

[0056] As described above, various exemplary embodiments disclosed have been described with reference to the accompanying drawings. Although exemplary embodiments of the invention have been shown and described, those skilled in the art will understand that these embodiments can be modified without departing from the principles and spirit of the invention, the scope of which is defined in the claims, etc.

[0057] According to one aspect of the disclosed invention, a sufficient battery SOC level is ensured in terrain mode so that the driving force of the electric motor is maximized during off-road driving.

Claims

1. A hybrid vehicle using an engine and an electric motor as a power source, comprising: an input configured to receive a user's selection of a terrain mode; a hybrid starter generator connected to the engine and configured to function as a starter motor to start the engine and as a generator to perform an idle charge when the engine is started; a battery electrically connected to the hybrid starter generator; and a controller configured to perform an idle charge using the hybrid starter generator when an SOC of the battery is less than or equal to a first SOC by starting the engine, wherein the controller is configured to adjust the SOC of the battery to perform an idle charge based on a second SOC greater than the first SOC when the terrain mode is entered, wherein the hybrid vehicle further comprises: a speed detector configured to detect a vehicle speed and transmit the vehicle speed to the controller; wherein the controller is configured to enter an EV drive mode until a first vehicle speed is reached in a stopped state of the hybrid vehicle and enter an HEV drive mode from the stopped state when the terrain mode is entered. The controller is configured to adjust the SOC of the battery to be maintained at the second SOC when the terrain mode is entered.

2. The hybrid vehicle according to claim 1, wherein 3. The hybrid vehicle according to claim 1, further comprising: an accelerator pedal detector configured to detect an amount of displacement of an accelerator pedal and transmit the amount of displacement of the accelerator pedal to the controller, wherein the controller is configured to enter an EV drive mode when the amount of displacement is not detected, enter an HEV drive mode when the amount of displacement is detected, and enter the HEV drive mode even when the amount of displacement is not detected when the terrain mode is entered. The controller is configured to adjust the SOC of the battery to be maintained at the second SOC by performing an idle charge based on the second SOC in the HEV drive mode when the terrain mode is entered.

4. The hybrid vehicle according to claim 3, wherein The controller is configured to adjust the SOC of the battery to be maintained at the second SOC by performing an idle charge based on the second SOC in the HEV drive mode when the terrain mode is entered.

5. The hybrid vehicle according to claim 1, wherein The controller is configured to enter the EV drive mode until the first vehicle speed is reached in a stopped state of the hybrid vehicle when the SOC of the battery is equal to or greater than the second SOC in the terrain mode.

6. The hybrid vehicle according to claim 5, wherein The controller is configured to adjust an operating point of the engine upward when the terrain mode is entered.

7. The hybrid vehicle according to claim 1, wherein 8. The hybrid vehicle according to claim 1, further comprising: a longitudinal acceleration detector configured to detect a longitudinal acceleration sensing value to calculate a road slope and transmit the detected longitudinal acceleration sensing value to the controller, wherein the controller is configured to adjust a magnitude of the second SOC in proportion to the slope in the terrain mode in response to determining that the road slope is an uphill slope.

9. The hybrid vehicle according to claim 8, further comprising: ​ an accelerator pedal detector configured to detect an amount of displacement of an accelerator pedal and transmit the amount of displacement of the accelerator pedal to the controller, wherein the controller is configured to, in the terrain mode, detect an amount of reduction in the number of rotations of a wheel when the amount of displacement is not detected, determine a load level based on the amount of reduction, and adjust the size of the SOC of the battery in proportion to the load level, and wherein the load level is in a proportional relationship with a gradient.

10. A control method of a hybrid vehicle using an engine and an electric motor as a power source, the control method comprising the steps of: receiving, by a controller, a selection of a terrain mode by a user; the controller performing an idle charge using a hybrid starter generator by starting the engine when an SOC of a battery is less than or equal to a first SOC; the controller adjusting the SOC of the battery based on a second SOC greater than the first SOC to perform an idle charge when entering the terrain mode, wherein the method further comprises the steps of: detecting a vehicle speed and transmitting the vehicle speed to the controller; and entering an EV drive mode until a first vehicle speed is reached in a stopped state of the hybrid vehicle, and entering an HEV drive mode from the stopped state when entering the terrain mode.

11. The method of claim 10, wherein, the step of performing an idle charge includes adjusting the SOC of the battery to be maintained at the second SOC when entering the terrain mode.

12. The method according to claim 10, further comprising the steps of: detecting an amount of displacement of an accelerator pedal and transmitting the amount of displacement of the accelerator pedal to the controller, and entering an EV drive mode when the amount of displacement is not detected, entering an HEV drive mode when the amount of displacement is detected, and entering the HEV drive mode even when the amount of displacement is not detected when entering the terrain mode.

13. The method according to claim 12, further comprising the step of: adjusting the SOC of the battery to be maintained at the second SOC by performing an idle charge based on the second SOC in the HEV drive mode when entering the terrain mode.

14. The method according to claim 10, further comprising the step of: adjusting the SOC of the battery to be maintained at the second SOC by performing an idle charge based on the second SOC in the HEV drive mode when entering the terrain mode.

15. The method according to claim 14, further comprising the step of: entering the EV drive mode until the first vehicle speed is reached in a stopped state of the hybrid vehicle when the SOC of the battery is equal to or greater than the second SOC in the terrain mode.

16. The method according to claim 10, further comprising the step of: adjusting an operating point of the engine upward when entering the terrain mode.

17. The method according to claim 10, further comprising the steps of: detecting a longitudinal acceleration sensing value to calculate a gradient of a road and transmitting the detected longitudinal acceleration sensing value to the controller, and In response to determining that the slope of the road is an uphill slope, the magnitude of the second SOC is adjusted in the terrain mode in proportion to the slope.

18. The method of claim 17, further comprising the steps of: detecting an amount of displacement of an accelerator pedal and transmitting the detected amount of displacement to a controller; and and in the terrain mode, when the amount of displacement is not detected, detecting an amount of reduction in the number of rotations of a wheel, determining a load level based on the amount of reduction, and adjusting the magnitude of the SOC of the battery in proportion to the load level, wherein the load level is in a proportional relationship with a slope.

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