Driving force adjusting device and adjusting method

Abstract

To provide a driving force adjusting device and an adjusting method which can ensure the driving stability of a vehicle while maximizing the ride feeling according to the distribution ratio of the driving force selected by a user.SOLUTION: A driving force adjusting device includes an input unit configured for receiving an input of a selection distribution ratio, which is a ratio of driving force generation of front wheels and rear wheels selected by a user, a receiving unit configured for receiving driving information of a vehicle, a driving force determination unit configured for determining a driving force distribution ratio, which is a driving force generation ratio of the front wheels and the rear wheels, and determining driving force of the front wheels and the rear wheels using the driving force distribution ratio, and a driving control unit configured for controlling a driving unit generating driving force of the vehicle based on the driving force determined by the driving force determination unit. The driving force determination unit can adjust the driving force distribution ratio on the basis of the driving information and the selection distribution ratio.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a driving force adjusting device and an adjusting method, and more particularly to a driving force adjusting device and an adjusting method that can ensure the running stability of a vehicle while maintaining a maximum riding feel according to a driving force distribution ratio selected by a user. [Background technology]

[0002] A conventional all-wheel drive system distributes the driving force generated by one power source (e.g., an internal combustion engine) to the front and rear wheels through clutch control. A conventional all-wheel drive system can fully engage the clutch and distribute the driving force to the front and rear wheels up to 50:50, but it cannot apply more than 50% of the driving force to the drive wheels that are not directly connected to the power source.

[0003] In contrast, recent all-wheel drive systems use two or more motors or a hybrid engine, making it possible to freely allocate drive force between the front and rear wheels, from 100% to the front wheels to 100% to the rear wheels.

[0004] This allows the user to adjust the distribution ratio of driving force between the front and rear wheels, and to experience and select the riding feel of front-wheel drive and rear-wheel drive using the same vehicle.

[0005] However, when the vehicle is turning, if the driving force distribution ratio selected by the user is maintained, oversteer, understeer, or excessive wheel slip may occur, resulting in a loss of driving stability.

[0006] On the other hand, when the driving force of the front and rear wheels is adjusted for driving stability, the user may not be able to obtain the riding feel he or she desires. Summary of the Invention [Problem to be solved by the invention]

[0007] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a driving force adjusting device and method that can ensure the running stability of a vehicle while maintaining a maximum riding comfort according to a driving force distribution ratio selected by a user. [Means for solving the problem]

[0008] To achieve the above-mentioned object, the driving force adjustment device of the present invention includes an input unit to which a selected distribution ratio, which is the driving force generation ratio of the front and rear wheels selected by a user, is input, a receiving unit to receive vehicle driving information, a driving force determination unit to determine a driving force distribution ratio, which is the driving force generation ratio of the front and rear wheels, and to determine the driving forces of the front and rear wheels using the driving force distribution ratio, and a drive control unit to control a drive unit that generates driving force in the vehicle based on the driving force determined by the driving force determination unit, and the driving force determination unit adjusts the driving force distribution ratio based on the driving information and the selected distribution ratio.

[0009] The drive force distribution ratio includes a first drive force distribution ratio, and the drive force determination unit: The first gradient ratio, which is the selected distribution ratio reset within a preset initial setting range, is determined as the distribution ratio of the driving force.

[0010] The initial setting range further includes a range in which the front wheels can be driven by a preset margin range even when the selected distribution ratio is input so that only the front wheels are driven, or a range in which the rear wheels can be driven by a preset margin range even when the selected distribution ratio is input so that only the rear wheels are driven.

[0011] The drive unit includes a first drive unit that generates a drive force at least to one of the front wheels or the rear wheels of the vehicle, and a second drive unit that generates a drive force to the other of the front wheels or the rear wheels of the vehicle.

[0012] The driving force distribution ratio includes a second driving force distribution ratio, and the driving force determination unit determines a first additional distribution ratio in consideration of a friction coefficient of a road surface on which the vehicle is traveling and the selected distribution ratio, and further applies the first additional distribution ratio to the driving force distribution ratio.

[0013] The driving force distribution ratio further includes a third driving force distribution ratio, and the third driving force distribution ratio is determined by further applying a second additional distribution ratio depending on the occurrence of understeer or oversteer of the vehicle to the driving force distribution ratio.

[0014] When understeer of the vehicle occurs, the second additional distribution ratio is determined according to an understeer index (US Index) indicating the degree of understeer within a preset limit additional distribution ratio.

[0015] When oversteer of the vehicle occurs, the second additional distribution ratio is determined by a weighting value determined in consideration of at least one of an oversteer index (OS Index) indicating the degree of oversteer, a friction coefficient of the road surface on which the vehicle is traveling, and the selected distribution ratio.

[0016] The driving unit includes a first driving unit that generates driving force to at least one of the front wheels or rear wheels of the vehicle, and a second driving unit that generates driving force to the other of the front wheels or rear wheels of the vehicle, and the driving force determination unit further includes a driving force redistribution unit that adjusts the driving force of the first driving unit and the driving force of the second driving unit distributed based on the driving force distribution ratio and redistributes the adjusted driving force to the first driving unit and the second driving unit.

[0017] When wheel slip exceeding an allowable wheel slip occurs in one of the first driving unit and the second driving unit, the driving force redistribution unit reduces the driving force distributed to the one of the first driving unit and the second driving unit where wheel slip exceeding the allowable wheel slip occurs, and redistributes the reduced driving force to the other of the first driving unit and the second driving unit.

[0018] The occurrence of wheel slip exceeding the allowable wheel slip is determined based on whether a wheel slip error determined by the magnitude of the received wheel slip exceeding a target wheel slip exceeds a preset allowable wheel slip, and the target wheel slip is a wheel slip required for the vehicle to travel along a target route.

[0019] The target wheel slip is set separately for the front wheels and the rear wheels, and when the selected distribution ratio is set larger for the front wheels, the target wheel slip for the front wheels is set larger than that for the rear wheels, and when the selected distribution ratio is set larger for the rear wheels, the target wheel slip for the rear wheels is set larger than that for the front wheels.

[0020] When the driving force of the first driving unit or the driving force of the second driving unit allocated based on the driving force allocation ratio exceeds the limit driving force of the first driving unit or the second driving unit, the driving force redistribution unit redistributes the excess driving force of the first driving unit or the second driving unit that exceeds the limit driving force to the first driving unit or the second driving unit that does not exceed the limit driving force, and the limit driving force is the maximum driving force that can be generated in the first driving unit or the second driving unit.

[0021] The driving force redistribution unit determines a reduction ratio of the excess driving force based on a turning index, and redistributes the driving force obtained by reducing the excess driving force using the reduction ratio to the first driving unit or the second driving unit that does not exceed the limit driving force.

[0022] To achieve the above object, another driving force adjusting method of the present invention includes a step of inputting a selected distribution ratio, which is the driving force generation ratio of the front and rear wheels selected by a user, a step of receiving vehicle driving information, a driving force determination step of determining a driving force distribution ratio, which is the driving force generation ratio of the front and rear wheels, and determining the driving forces of the front and rear wheels using the driving force distribution ratio, and a step of generating driving forces at the front and rear wheels based on the determined driving forces, and the driving force determination step adjusts the driving force distribution ratio based on the driving information and the selected distribution ratio.

[0023] The driving information includes the driver's requested torque, wheel slip information, vehicle driving speed information, steering angle, friction coefficient of the road surface during driving, yaw rate, and yaw acceleration.

[0024] The driving force determination step determines a first gradient ratio, which is the selected distribution ratio reset within a preset initial setting range, as the distribution ratio of the driving force, and the initial setting range is a range which is set taking into consideration a preset margin distribution ratio of the front wheels or the rear wheels.

[0025] The driving force determining step determines a first additional distribution ratio in consideration of a friction coefficient of a road surface on which the vehicle is traveling and the selected distribution ratio, and further applies the first additional distribution ratio to the distribution ratio of the driving force.

[0026] The driving force determining step determines the driving force by further applying a second additional distribution ratio, which is determined differently depending on whether the vehicle is understeered or oversteered, to the driving force distribution ratio.

[0027] When a driving force exceeding the magnitude of wheel slip occurring in the vehicle or the limit driving force of the front or rear wheels is required, the driving force of the front wheels and the driving force of the rear wheels distributed based on the distribution ratio of the driving force are adjusted to redistribute the driving force between the front wheels and the rear wheels. Effect of the Invention

[0028] According to the driving force adjusting device and method of the present invention, the driving stability of the vehicle can be ensured while the user can feel the maximum riding comfort according to the selected distribution ratio set by the user. [Brief description of the drawings]

[0029] [Figure 1] FIG. 2 is a block diagram of the driving force adjusting device of the present invention. [Diagram 2] FIG. 4 is a detailed block diagram of a driving force determining unit according to the present invention. [Diagram 3] FIG. 2 is a block diagram of a driving force adjusting method according to the present invention; [Figure 4] 4 is a diagram showing an example of a selected distribution ratio and a distribution ratio of a first driving force according to the present invention; [Diagram 5] 2 is a diagram showing a driving force control of a vehicle in an oversteer or understeer state according to the present invention; [Figure 6] 1 is a graph showing the first additional allocation ratio of the present invention. [Figure 7] 4 is a graph showing an example of a second additional distribution ratio of the present invention when understeer occurs. [Figure 8] 4 is a graph showing an example of a second additional distribution ratio of the present invention when oversteer occurs. [Figure 9] 4 is a graph showing an example of a second additional distribution ratio of the present invention when oversteer occurs. [Figure 10] 4 is a graph showing an example of a second additional distribution ratio of the present invention when oversteer occurs. [Figure 11] 4 is a graph showing a driving limit of a driving unit of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Since the present invention can be modified in various ways and has various embodiments, specific embodiments are illustrated in the drawings and described in detail. However, this does not limit the present invention to the specific embodiments, and it can be understood that the present invention includes all modifications, equivalents, and alternatives within the spirit and technical scope of the present invention.

[0031] Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only to distinguish one component from another. For example, a first component can be named a second component, and similarly, the second component can be named a first component, without departing from the scope of the invention. The term "and / or" includes any combination of two or more associated items or two or more associated items.

[0032] The terms used in this application are merely used to describe specific embodiments and are not intended to limit the present invention. A singular expression includes a plural expression unless the context clearly indicates otherwise. In this application, the terms "include" or "have" specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, and should be understood not to preclude the presence or additional possibility of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0033] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning they have in the context of the relevant art, and should not be interpreted as having an ideal or overly formal meaning unless expressly defined in this application.

[0034] The present invention will now be described in more detail with reference to the accompanying drawings.

[0035] FIG. 1 is a block diagram of a driving force adjusting device of the present invention, and FIG. 2 is a detailed block diagram of a driving force determining unit 300 of the present invention.

[0036] The driving force adjustment device of the present invention adjusts the driving force of the front and rear wheels of a vehicle, thereby allowing the user to maximize the driving feel of front-wheel driving and rear-wheel driving based on the drive ratio selected by the user, while ensuring the driving stability of the vehicle.

[0037] In particular, when understeer, oversteer, or wheel slip occurs during cornering, the driving force adjusting device according to one embodiment of the present invention controls the vehicle posture while maximally maintaining the driving feel of front-wheel driving and rear-wheel driving based on the drive ratio selected by the user.

[0038] As shown in FIG. 1, the driving force adjusting device of the present invention includes an input unit 100 , a receiving unit 200 , a driving force determining unit 300 , a driving control unit 400 , and a driving unit 500 .

[0039] The input unit 100 inputs a ratio of driving force to be generated at the front and rear wheels as desired by the user. The input unit 100 is a touch-sensitive display (e.g., AVN (Audio, Video, Navigation)) included in the cluster of the vehicle, and the user inputs the ratio of driving force to be generated at the front and rear wheels as desired by the user through touch.

[0040] Also, the input unit 100 can input using voice. The input unit 100 includes an audio system and a microphone in the vehicle, and recognizes the user's voice to input the ratio of driving force to be generated by the front wheels and the rear wheels.

[0041] The input unit 100 is not limited to the above-mentioned display, audio, and microphone, as long as it is a means by which the user can input a request for the ratio of driving force to be generated by the front and rear wheels.

[0042] A user inputs a desired ratio of driving forces to be generated by the front and rear wheels via the input unit 100. For example, a user inputs a value between 0:100 and 100:0 as the ratio of driving forces to be generated by the front and rear wheels via the input unit 100.

[0043] Alternatively, the user operates the input unit 100 to adjust the ratio by a preset amount between 0:100 or 100:0. For example, the user uses the plus and minus input buttons displayed on the input unit 100 to add or subtract a preset amount (e.g., 5 or 10) to input the desired ratio of driving force to be generated by the front and rear wheels.

[0044] The receiving unit 200 receives information about the vehicle's running state, such as a driver's required torque, wheel slip information, vehicle running speed information, steering angle, friction coefficient of the road surface during running, yaw rate, and yaw acceleration.

[0045] However, without being limited thereto, the receiving unit 200 receives driving information that can estimate the driver's required torque, wheel slip information, vehicle driving speed information, steering angle, friction coefficient of the road surface during driving, yaw rate, and yaw acceleration.

[0046] For example, the receiving unit 200 further includes driving information such as accelerator pedal stroke information, wheel speed of each wheel, vehicle driving speed information, etc. Here, the driver's required torque can be estimated based on the accelerator pedal stroke information, and wheel slip can be estimated based on the difference between the wheel speed of each wheel and the vehicle driving speed.

[0047] The receiving unit 200 is connected to a sensor installed in the vehicle through a network installed in the vehicle to receive information on the running state of the vehicle. For example, the receiving unit 200 receives brake pedal stroke information from an accelerator pedal sensor through a controller area network (CAN) network of the vehicle.

[0048] The driving force determination unit 300 determines a driving force distribution ratio according to a user's setting and a vehicle running state. The driving force determination unit 300 applies the determined driving force distribution ratio to a required driving force transmitted by the user's operation of the accelerator pedal to determine the driving forces of the front and rear wheels.

[0049] The drive control unit 400 controls the drive unit 500 to generate a drive force for the vehicle according to the drive force determined by the drive force determination unit 300 .

[0050] Here, the driving unit 500 is a device that generates a driving force for the vehicle to run. There are at least two driving units 500, which generate driving force for the front wheels and driving force for the rear wheels in a mutually interchangeable manner.

[0051] The driving unit 500 includes a first driving unit 510 that generates a driving force for the front wheels and a second driving unit 520 that generates a driving force for the rear wheels. However, the present invention is not limited thereto, and the first driving unit 510 generates a driving force for the rear wheels, and the second driving unit 520 generates a driving force for the front wheels.

[0052] The first drive unit 510 and the second drive unit 520 each include at least one electric motor or engine, and generate driving force for the front and rear wheels, respectively.

[0053] In addition, the first driving unit 510 and the second driving unit 520 are combined in various ways to generate driving force for the vehicle. For example, the first driving unit 510 and the second driving unit 520 may both be configured with an electric motor or both be configured with an engine. Alternatively, one of the first driving unit 510 and the second driving unit 520 may be configured with an electric motor and the other driving unit 500 may be configured with an engine.

[0054] In addition, the first driving unit 510 and the second driving unit 520 are in-wheel motors mounted on individual wheels to generate driving force, but are not limited to this, and various means for generating driving force for the vehicle can be applied to the driving unit 500.

[0055] The components of the driving force adjusting device can be connected by wire or wirelessly to transmit and receive information. For example, data can be transmitted and received using communication means such as Ethernet, Media Oriented Systems Transport (MOST), Flexray, Controller Area Network (CAN), Local Interconnect Network (LIN), Internet, LTE, 5G, Wi-Fi, Bluetooth, Near Field Communication (NFC), Zigbee, and Radio Frequency (RF).

[0056] As shown in FIG. 2, the driving force determination unit 300 includes a first driving force distribution ratio determination unit 310, a driving state judgment unit 320, a second driving force distribution ratio determination unit 330, a third driving force determination unit 340, and a driving force redistribution unit 350.

[0057] The first driving force distribution ratio determination unit 310 determines the distribution ratio of the first driving force based on the distribution ratio of the driving force input by the user. Here, the distribution ratio of the driving force input by the user via the input unit 100 is set as the selected distribution ratio.

[0058] FIG. 4 is a diagram showing an example of a selected distribution ratio and a first driving force distribution ratio of the present invention, and FIG. 5 is a diagram showing a driving force control of a vehicle in an oversteer or understeer state of the present invention.

[0059] First, referring to FIG. 5, a process of controlling the vehicle attitude by adjusting the driving force of the vehicle when understeer (see FIG. 5(a)) or oversteer (see FIG. 5(b)) occurs during turning will be described.

[0060] As shown in FIG. 5(a), understeer is a state in which the vehicle deviates from a target path according to the vehicle's running speed and steering angle, and the actual path runs at a greater curvature than the target path.

[0061] In this case, the frictional force acting on the front wheels occurs in a saturated state away from the friction source, so in order to avoid understeer, it is necessary to transmit part of the driving force of the front wheels to the rear wheels.

[0062] That is, in order to overcome understeer, it is necessary to distribute a larger driving force to the rear wheels in preparation for the distribution ratio of driving force when understeer occurs by adjusting the distribution ratio of driving force. Here, distributing a larger driving force to the rear wheels in preparation for the distribution ratio of driving force when understeer occurs is called rear wheel shifting of driving force.

[0063] Also, as shown in FIG. 5(b), oversteer is a state in which the vehicle deviates from a target route according to the vehicle's traveling speed and steering angle, and the actual route travels with a smaller curvature than the target route.

[0064] In this case, the frictional force acting on the rear wheels occurs in a saturated state away from the friction source, so in order to avoid an oversteer state, it is necessary to transmit part of the driving force of the rear wheels to the front wheels.

[0065] That is, in order to overcome oversteer, it is necessary to distribute a larger driving force to the front wheels in preparation for the distribution ratio of the driving force when oversteer occurs by adjusting the distribution ratio of the driving force. Here, distributing a larger driving force to the front wheels in preparation for the distribution ratio of the driving force when oversteer occurs is called front-wheel driving force.

[0066] As shown in Fig. 4 again, the user inputs a selected distribution ratio via the input unit 100. Referring to the input unit 100 exemplarily shown in Fig. 4, the input unit 100 includes eleven boxes for changing the ratio of rear wheel driving force to front wheel driving force from 100:0 to 0:100, which is a ratio of 10%. In addition, the user inputs the selected distribution ratio by selecting one of the eleven boxes displayed on the input unit 100.

[0067] Meanwhile, the adjustment amount of the selected distribution ratio is not limited to 10%, and the ratio of rear wheel driving force to front wheel driving force can be changed in 5% or 1% increments or continuously from 100:0 to 0:100.

[0068] Furthermore, the means by which the user inputs the selected distribution ratio is not limited to selection on the display, but various input means can be applied, such as operating dial buttons or inputting via voice.

[0069] On the other hand, if the distribution ratio of the driving force of the vehicle is determined by directly applying the distribution ratio selected by the user, a problem may occur in the running stability of the vehicle.

[0070] A user sets a selected distribution ratio so that the ratio of either the front wheels or the rear wheels is higher. For example, a user selects a selected distribution ratio of 100:0 or 0:100 for the rear wheel driving force to the front wheel driving force. In this case, if the vehicle understeers or oversteers, it is not possible to shift the driving force to the rear wheels or the front wheels, making it difficult to overcome the understeer or oversteer state.

[0071] Therefore, the first driving force distribution ratio determination unit 310 determines the distribution ratio of the first driving force by adjusting the selected distribution ratio within the initial setting range.

[0072] Here, the initial setting range is a range in which the selected distribution ratio is limited in order to ensure a margin of driving force for the front and rear wheels.

[0073] As shown in FIG. 4, for example, the initial setting range can be set from 70:30 to 30:70 for the rear wheel drive force relative to the front wheel drive force, and the drive force distribution ratio can have a minimum margin range of 30% in the front or rear wheel direction regardless of the selected distribution ratio.

[0074] Meanwhile, the initial setting range can be set in various ways depending on the type of vehicle.

[0075] The running state determination unit 320 determines the running state of the vehicle. Here, the running state of the vehicle includes whether or not the vehicle is turning, the occurrence of understeer, the occurrence of oversteer, the occurrence of wheel slip, and the like.

[0076] The driving state determination unit 320 determines whether the vehicle is turning or not. The driving state determination unit 320 estimates a turning index that indicates the degree of curvature of the path on which the vehicle is turning.

[0077] Here, the turning index can be estimated using the steering angle, yaw rate, and yaw acceleration of the vehicle. The larger the turning index, the larger the curvature of the path during turning can be, and the smaller the turning index, the closer the path during turning to a straight line.

[0078] In addition, the driving state determination unit 320 determines whether understeer or oversteer has occurred in the vehicle during turning.

[0079] Here, the oversteer state is a state in which the turning radius of the vehicle is smaller than the angle at which the steering wheel is turned while the understeer state is a state in which the turning radius of the vehicle is larger than the angle at which the steering wheel is turned while the vehicle is turning.

[0080] The vehicle driving state determination unit 320 estimates the understeer index (US Index) or oversteer index (OS Index) along with the occurrence of understeer or oversteer. Here, the understeer index (US Index) is an index indicating the degree of understeer that has occurred in the vehicle. The oversteer index (OS Index) is an index indicating information on oversteer that has occurred in the vehicle.

[0081] The driving state determination unit 320 calculates a target yaw rate using the vehicle's driving speed and steering angle, and calculates a yaw rate error amount, which is the difference between the target yaw rate and the current yaw rate. The driving state determination unit 320 determines an understeer index (US Index) or an oversteer index (OS Index) by combining an estimated value of the vehicle's lateral slip angle and the yaw rate error amount.

[0082] The second driving force distribution ratio determination unit 330 determines the distribution ratio of the second driving force by taking into consideration a first additional distribution ratio determined based on the friction coefficient of the road surface during traveling to the distribution ratio of the first driving force.

[0083] When the vehicle is traveling in a straight line, the user may hardly feel the difference in the distribution ratio of the driving force of the vehicle. The section where the user feels the difference in the distribution ratio of the driving force of the vehicle is a cornering section, especially a critical driving section where understeer or oversteer occurs.

[0084] The driving force adjusting device of the present invention applies a first additional distribution ratio when entering a cornering run, and further applies a second additional distribution ratio when making a limit turn, thereby ensuring the driving stability of the vehicle while maximizing the riding comfort according to the selected distribution ratio set by the user.

[0085] When the vehicle is turning, the second driving force distribution ratio determination unit 330 determines the first additional distribution ratio based on the friction coefficient of the road surface.

[0086] 6 is a graph showing the first additional distribution ratio of the present invention, where line a is a line diagram for a high friction road surface where the friction coefficient of the road surface on which the vehicle is traveling is greater than a preset friction coefficient, line c is a line diagram for a low friction road surface where the friction coefficient of the road surface on which the vehicle is traveling is less than a preset friction coefficient, and line b is a line diagram for any road surface between the high friction road surface and the low friction road surface.

[0087] As shown in Fig. 6, the first additional distribution ratio is determined based on the distribution ratio selected by the user. The first additional distribution ratio is determined in proportion to the drive ratio distributed to the front wheels. The first additional distribution ratio increases or decreases in the same manner as the drive ratio distributed to the front wheels increases or decreases.

[0088] Here, as shown in FIG. 6, the first additional allocation ratio increases linearly in proportion to the user's selected allocation ratio, but is not limited thereto, and increases or decreases nonlinearly in response to an increase or decrease in the user's selected allocation ratio.

[0089] Furthermore, when the same selected distribution ratio is set, the first additional distribution ratio when traveling on a high friction road surface is greater than the first additional distribution ratio when traveling on a low friction road surface.

[0090] Here, the high friction road surface is a road surface on which the friction coefficient of the road surface on which the vehicle is traveling is greater than a preset friction coefficient, and in the case of the high friction road surface, the same first additional distribution ratio is applied regardless of the friction coefficient.

[0091] In addition, the low friction road surface is a road surface on which the friction coefficient of the road surface on which the vehicle is traveling is smaller than a preset friction coefficient, and in the case of the low friction road surface, the same first additional distribution ratio is applied regardless of the friction coefficient.

[0092] In addition, when the friction coefficient of the road surface on which the vehicle is traveling is between a high friction road surface and a low friction road surface, the first additional allocation ratio can be estimated and applied using an interpolation method or the like based on the first additional allocation ratio of the high friction road surface and the first additional allocation ratio of the low friction road surface.

[0093] The second driving force distribution ratio determination unit 330 determines the distribution ratio of the second driving force by taking the first additional distribution ratio into consideration in addition to the distribution ratio of the first driving force.

[0094] When the vehicle understeers or oversteers while turning, it is necessary to further adjust the distribution ratio of the driving force of the vehicle in order to maintain the running stability of the vehicle.

[0095] The third driving force distribution ratio determination unit 340 determines the distribution ratio of the third driving force by considering a second additional distribution ratio determined based on the occurrence of understeer or oversteer in the distribution ratio of the second driving force. Here, the third driving force distribution ratio determination unit 340 receives the vehicle running state (e.g., occurrence of understeer or oversteer, etc.) from the running state determination unit 320.

[0096] The third driving force distribution ratio determination unit 340 sets the second additional distribution ratio so that the second additional distribution ratio is different when understeer occurs and when oversteer occurs.

[0097] FIG. 7 is a graph showing an example of the second additional allocation ratio of the present invention when understeer occurs, FIG. 8 is a graph showing an example of the second additional allocation ratio of the present invention when oversteer occurs, FIG. 9 is a graph showing an example of the second additional allocation ratio of the present invention when oversteer occurs, and FIG. 10 is a graph showing an example of the second additional allocation ratio of the present invention when oversteer occurs.

[0098] As shown in FIG. 7, when understeer occurs in the vehicle, the third driving force distribution ratio determination unit 340 of the present invention adjusts the distribution ratio of the driving force.

[0099] Here, US Index is the understeer index (US Index), x is the marginal additional allocation ratio, and y represents the second additional allocation ratio in any US Index.

[0100] When the vehicle understeers, the third driving force distribution ratio determination unit 340 decreases the distribution ratio of the driving force to the front wheels and increases the distribution ratio of the driving force to the rear wheels based on the degree of understeer.

[0101] Here, the third driving force distribution ratio determination unit 340 estimates the occurrence degree of understeer based on an understeer index (US Index).

[0102] When a vehicle understeers, the frictional force of the front wheels exceeds the friction coefficient, and the driving force of the front wheels is transmitted to the rear wheels to eliminate the understeer.

[0103] On the other hand, when the distribution ratio of the driving force of the vehicle is shifted to the rear wheels without any restrictions in order to overcome understeer of the vehicle as in the conventional technology of FIG. 7, the riding sensation according to the selected distribution ratio selected by the user is difficult to feel, and when the understeer is severe, the riding sensation is opposite to the selected distribution ratio selected by the user.

[0104] For example, if a user selects front-wheel drive (e.g., a driving force distribution ratio of the rear wheels to the front wheels is 100:0) as the selected distribution ratio, and there is severe understeer and the second additional distribution ratio is determined to be 100%, the vehicle's driving force distribution ratio will be changed to a driving force distribution ratio opposite to the user's selected distribution ratio (e.g., a driving force distribution ratio of the rear wheels to the front wheels is 0:100).

[0105] In order to solve the above-mentioned problem, the third driving force distribution ratio limits the second additional distribution ratio to be changed within the limit additional distribution ratio when understeer occurs.

[0106] As shown in Figure 7, the magnitude (y) of the second additional distribution ratio may increase as the understeer index (US Index) increases. The magnitude (y) of the second additional distribution ratio changes based on the understeer index (US Index) regardless of the magnitude of the driving force distribution ratio. However, the magnitude (y) of the second additional distribution ratio does not exceed the limit additional distribution ratio (x).

[0107] When understeer occurs, the third driving force distribution ratio determination unit 340 shifts the driving force to the rear wheels by the magnitude (y) of the second additional distribution ratio.

[0108] For example, the limit additional distribution ratio (x) is preset to 10%. When understeer occurs, the distribution ratio of the third driving force shifts driving force to the rear wheels by the magnitude (y) of the second additional distribution ratio. Here, the second additional distribution ratio changes according to the understeer index (US Index), but does not exceed the limit additional distribution ratio (x) of 10%.

[0109] As shown in FIGS. 8 to 10, when oversteer occurs in the vehicle, the third driving force distribution ratio determination unit 340 of the present invention adjusts the driving force distribution ratio.

[0110] Here, the OS Index is an oversteer index, and the OS Index is an index that indicates the degree of oversteer occurring in a vehicle.

[0111] When oversteer occurs in the vehicle, the third driving force distribution ratio determination unit 340 decreases the distribution ratio of the driving force of the rear wheels and increases the distribution ratio of the driving force of the front wheels based on the degree of oversteer.

[0112] In other words, the third driving force distribution ratio determination unit 340 allocates driving force to the front wheels in order to eliminate oversteer of the vehicle.

[0113] The third driving force distribution ratio determination unit 340 estimates the second additional distribution ratio based on the understeer index (US Index). The third driving force distribution ratio determination unit 340 determines at least one additional distribution ratio based on the understeer index (US Index) and determines the sum of the at least one additional distribution ratio as the second additional distribution ratio.

[0114] 8, when oversteer occurs, the third driving force distribution ratio determination unit 340 determines the second additional distribution ratio based on the oversteer index (OS Index). Here, the second additional distribution ratio increases linearly in proportion to the oversteer index (OS Index). However, the second additional distribution ratio is not limited thereto, and may increase or decrease nonlinearly based on the oversteer index (OS Index) or increase or decrease based on various functions.

[0115] Furthermore, as shown in FIG. 9, when oversteer occurs, the third driving force distribution ratio determination unit 340 determines the second additional distribution ratio based on the friction coefficient of the road surface on which the vehicle is traveling.

[0116] Here, the second additional distribution ratio decreases linearly in proportion to the increase in the friction coefficient, but is not limited thereto, and the second additional distribution ratio may increase or decrease nonlinearly in the opposite direction to the friction coefficient, or may increase or decrease based on various functions.

[0117] Furthermore, as shown in FIG. 10, when oversteer occurs, the third driving force distribution ratio determination unit 340 determines the second additional distribution ratio based on the selected distribution ratio selected by the driver.

[0118] Here, the second additional distribution ratio increases linearly in proportion to the ratio of the driving force of the front wheels. More specifically, the second additional distribution ratio decreases as the ratio of the driving force of the rear wheels increases, and increases as the ratio of the driving force of the front wheels increases.

[0119] However, without being limited thereto, the second additional distribution ratio may be increased or decreased nonlinearly based on the ratio of the driving force of the front wheels or the ratio of the driving force of the rear wheels, or may be increased or decreased based on various functions.

[0120] In addition, when oversteer occurs, the third driving force distribution ratio determination unit 340 determines the second additional distribution ratio based on an oversteer index (OS Index), a friction coefficient of the road surface during traveling, or a selected distribution ratio.

[0121] For example, when oversteer occurs, the third driving force distribution ratio determination unit 340 determines at least one distribution ratio determined based on an oversteer index (OS Index), a friction coefficient of the road surface during driving, or a selected distribution ratio as the second additional distribution ratio.

[0122] In addition, the third driving force distribution ratio determination unit 340 determines a second additional distribution ratio by summing at least two additional distribution ratios determined based on the oversteer index (OS Index), the friction coefficient of the road surface during driving, or the selected distribution ratio.

[0123] When a vehicle oversteers, the frictional force of the rear wheels exceeds the friction coefficient, and the driving force of the rear wheels is transmitted to the front wheels to eliminate the oversteer.

[0124] On the other hand, when the drive ratio of the vehicle is shifted to the front wheels without any restrictions, the user will not feel a riding sensation according to the selected distribution ratio, and if there is severe oversteer, the user will feel a riding sensation opposite to the selected distribution ratio.

[0125] Therefore, the third driving force distribution ratio determination unit 340 determines the second excess distribution ratio to be within the limit additional distribution ratio when oversteer occurs, as well as when understeer occurs.

[0126] Accordingly, the third driving force distribution ratio determination unit 340 adjusts the maximum value of each of the additional distribution ratios determined based on the oversteer index, the friction coefficient of the road surface during driving, or the selected distribution ratio depending on the number of factors that determine the second additional distribution ratio when oversteer occurs.

[0127] Alternatively, the third driving force allocation ratio determination unit 340 determines the second additional allocation ratio as the sum of the additional allocation ratios determined by multiple elements, and when the magnitude of the second additional allocation ratio exceeds the limit additional allocation ratio, it determines the second additional allocation ratio as the limit additional allocation ratio.

[0128] The driving force determination unit 300 applies the driving force distribution ratio determined by the first to third driving force distribution ratio determination unit 340 to the required driving force transmitted by the user's operation of the accelerator pedal, thereby determining the driving force for the front wheels and the driving force for the rear wheels, respectively.

[0129] The driving force redistribution unit 350 redistributes the driving force between the front wheels and the rear wheels according to the driving force distribution ratio.

[0130] The driving force redistribution unit 350 redistributes the front wheel driving force and the rear wheel driving force for the driving stability of the vehicle when excessive wheel slip occurs in the front or rear wheels of the vehicle. Here, when excessive wheel slip occurs, wheel slip that exceeds the allowable wheel slip occurs.

[0131] More specifically, when wheel slip exceeding the allowable wheel slip occurs in the front or rear wheels of the vehicle, the driving force redistribution unit 350 transmits and redistributes a portion of the driving force of one of the front or rear wheels where wheel slip exceeding the allowable wheel slip has occurred to the other of the front or rear wheels.

[0132] For driving stability, the driving condition determination unit 320 estimates and monitors wheel slip of the front or rear wheels periodically or in real time.

[0133] More specifically, the running state determining unit 320 determines whether or not a wheel slip exceeding an allowable wheel slip has occurred in the vehicle based on the wheel slip error.

[0134] Here, the wheel slip error is a value calculated from the difference between the current wheel slip and the target wheel slip, and if the wheel slip error is larger than a preset allowable wheel slip value, it is determined that wheel slip exceeding the allowable wheel slip has occurred.

[0135] Here, the target wheel slip is the wheel slip required for the vehicle to travel along the target route. As shown in Figure 5 again, when the vehicle turns to the target route, the vehicle will inevitably experience wheel slip, although this will vary depending on the radius of the target route.

[0136] When the difference between the wheel slip occurring in a turning vehicle and the target wheel slip is equal to or greater than a certain difference, it is determined that wheel slip exceeding the allowable wheel slip has occurred in the vehicle and there is a problem with the vehicle behavior.

[0137] Therefore, the driving condition determination unit 320 compares the wheel slip error, which is the difference between the current wheel slip and the target wheel slip, with a preset allowable wheel slip to determine whether wheel slip exceeding the allowable wheel slip has occurred.

[0138] The driving state determination unit 320 adjusts the target wheel slip of the front and rear wheels according to the selected distribution ratio. By adjusting the target wheel slip and adjusting the wheel slip error, the driving state determination unit 320 may make different determinations as to whether or not wheel slip exceeding the allowable wheel slip has occurred even when the same wheel slip occurs.

[0139] For example, when the user selects a selected distribution ratio such that a larger proportion of the driving force is distributed to the front wheels, the driving state judgment unit 320 sets the magnitude of the target wheel slip for the front wheels to be larger than the target wheel slip for the rear wheels.

[0140] In other words, if the user wishes to feel an even greater driving force from the front wheels, the target wheel slip for the front wheels can be set even larger, allowing the front wheels to tolerate even greater wheel slip, allowing the user to feel a stronger riding sensation unique to front-wheel drive.

[0141] In addition, when the user selects a selected distribution ratio so as to distribute a larger amount of driving force to the rear wheels, the driving state judgment unit 320 sets the magnitude of the target wheel slip of the rear wheels to be larger than the target wheel slip of the front wheels.

[0142] In other words, if the user wishes to feel an even greater driving force from the rear wheels, the target wheel slip for the rear wheels can be set even larger, allowing the rear wheels to tolerate even greater wheel slip, allowing the user to feel a stronger riding sensation unique to rear-wheel drive.

[0143] Additionally, a target wheel slip adjustment magnitude is determined based on the selected allocation ratio.

[0144] For example, if the user selects a 50:50 distribution ratio of front wheel drive force to rear wheel drive force, the driving state determination unit 320 sets the target wheel slip of the front and rear wheels to be the same. Also, as the user increases the drive force of the front or rear wheels, the target wheel slip of the front or rear wheels is increased in proportion.

[0145] FIG. 11 is a graph showing the driving limits of the driving section 500 of the present invention.

[0146] As shown in Fig. 11, when the driving unit 500 is an electric motor, it is difficult for the driving unit 500 to generate torque equal to or greater than the maximum torque z. Fig. 11 shows an example of an electric motor, but even when the driving unit 500 is an engine, it is not possible to generate a driving force equal to or greater than the maximum output of the engine.

[0147] In other words, the driving unit 500 has a limit to the driving force that it can generate. Here, the limit of the driving force that the driving unit 500 can generate is referred to as the limit driving force.

[0148] The driving force redistribution unit 350 redistributes the driving force when the driving force of the front wheels and the driving force of the rear wheels determined using the driving force distribution ratio determined by the first to third driving force distribution ratio determination unit 340 exceeds the limit driving force of the driving unit 500.

[0149] The driving force redistribution unit 350 redistributes the driving force by transmitting the driving force of the front wheels or the driving force of the rear wheels that exceeds the limit driving force to the front wheels or the rear wheels that does not exceed the limit driving force.

[0150] When the vehicle is traveling straight, redistributing the driving force of the vehicle does not have a significant effect on the riding comfort of the user, whereas when the vehicle is turning (especially when understeer or oversteer occurs), redistributing the driving force of the vehicle can have a significant effect on the riding comfort of the user.

[0151] Accordingly, the driving force redistribution unit 350 determines a reduction ratio of the driving force that exceeds the limit driving force using the turning index, and transmits the driving force applied to the driving force that exceeds the limit driving force by the determined reduction ratio to the driving unit 500 that does not exceed the limit driving force.

[0152] Here, the turning index is estimated using the steering angle, yaw rate, and yaw acceleration of the vehicle. The larger the turning index, the greater the curvature of the path during turning, and the smaller the turning index, the closer the path during turning to a straight line.

[0153] The reduction ratio is determined in proportion to the turning index. The reduction ratio increases as the turning index increases, and decreases as the turning index decreases. That is, a high reduction ratio is applied to a route with a sharp curve and a large turning index, and a low reduction ratio is applied to a route that is close to a straight line and has a small turning index.

[0154] The driving force redistribution unit 350 multiplies the driving force exceeding the limit driving force by a reduction ratio, and transmits the reduced driving force to the driving unit 500 where the limit driving force is not exceeded, thereby redistributing the driving force.

[0155] The driving force redistribution unit 350 uses a reduction ratio determined by the turning index to compensate for a portion of the driving force that exceeds the limit driving force, thereby satisfying the user's required driving force to the maximum extent possible while maintaining a riding feel according to the driving force distribution ratio set by the user.

[0156] FIG. 3 is a block diagram of the driving force adjusting method of the present invention.

[0157] As shown in FIG. 3, the driving force adjusting method of the present invention includes a step of inputting a selected distribution ratio, a step of determining a first driving force distribution ratio, a step of receiving driving information, a step of determining a second driving force distribution ratio, a step of determining a third driving force distribution ratio, and a step of redistributing the driving forces.

[0158] The step of inputting the selected distribution ratio is a step in which the selected distribution ratio selected by the user is input through the input unit 100 provided in the vehicle.

[0159] In order to obtain a riding feel that the user desires, the user can input a selected distribution ratio via the input unit 100. Here, the user can input a distribution ratio of rear wheel driving force to front wheel driving force in a range from 0:100 to 100:0.

[0160] The step of determining the first driving force distribution ratio is a step of adjusting the driving force distribution ratio so that the selected distribution ratio input by the user is within a preset initial setting range. Here, the initial setting range is a range for securing a margin of the driving force distribution ratio to the front wheels and the rear wheels, and is a range excluding the margin range set on the front wheel side and the rear wheel side of the driving force distribution ratio.

[0161] For example, when the margin range is set to 30%, the initial setting range is set to a range of 70:30 to 30:70 in terms of the distribution ratio of rear wheel driving force to front wheel driving force, excluding 30% for the front wheels and 30% for the rear wheels.

[0162] The step of determining the distribution ratio of the first driving force is a step of determining a distribution ratio of the first driving force in which the selected distribution ratio is adjusted to match the initial setting range.

[0163] The step of receiving the driving information is a step of driving the vehicle according to the first driving force distribution ratio and receiving driving information of the vehicle.

[0164] Here, the driving information includes the driver's requested torque, wheel slip information, vehicle driving speed information, steering angle, friction coefficient of the road surface during driving, yaw rate, yaw acceleration, and the like.

[0165] The step of determining the distribution ratio of the second driving force is a step of determining the distribution ratio of the second driving force by applying a first additional distribution ratio determined according to the friction coefficient of the road surface during driving and the selected distribution ratio to the distribution ratio of the first driving force.

[0166] The step of determining the distribution ratio of the third driving force is a step of determining a distribution ratio of the third driving force by applying a second additional distribution ratio determined depending on understeer or oversteer of the vehicle to the distribution ratio of the second driving force.

[0167] The driving force adjusting method of the present invention applies a first additional distribution ratio when entering a cornering run, and further applies a second additional distribution ratio during limit cornering run, thereby ensuring the driving stability of the vehicle while maximizing the riding comfort according to the selected distribution ratio set by the user.

[0168] Here, the second additional distribution ratio is determined in different ways when understeer and oversteer occur.

[0169] When understeer occurs, the second additional distribution ratio is determined in proportion to the understeer index (US Index), and the second additional distribution ratio cannot exceed the limit additional distribution ratio.

[0170] When oversteer occurs, the second additional distribution ratio is determined based on the oversteer index, the friction coefficient of the road surface on which the vehicle is traveling, or the selected distribution ratio. As with understeer, when oversteer occurs, it is preferable that the second additional distribution ratio does not exceed the limit additional distribution ratio.

[0171] The step of redistributing the driving force is a step of redistributing the driving force between the front wheels and the rear wheels determined according to the driving force distribution ratio.

[0172] In the step of redistributing the driving force, the driving force redistributor 350 redistributes the front wheel driving force and the rear wheel driving force for the driving stability of the vehicle when wheel slip exceeding an allowable wheel slip occurs in the front or rear wheels of the vehicle.

[0173] The occurrence of wheel slip exceeding the allowable wheel slip of the front or rear wheels can be determined using a wheel slip error, which is a value calculated from the difference between the current wheel slip and a target wheel slip.

[0174] Here, the target wheel slip is applied by changing the target wheel slip ratios of the front and rear wheels based on the selected distribution ratio.

[0175] For example, if the user wishes to feel a greater driving force from the rear wheels, the target wheel slip for the rear wheels can be set greater than the target wheel slip for the front wheels, allowing the rear wheels to slip even more, allowing the user to feel a stronger riding sensation peculiar to rear-wheel drive.

[0176] In addition, in the step of redistributing the driving force, the driving force of the front wheels and the driving force of the rear wheels are redistributed using a driving force distribution ratio that exceeds the limit driving force of the driving unit 500. Here, the limit driving force is the maximum driving force that can be generated by the driving unit 500, and the driving force that exceeds the limit driving force among the driving force of the front wheels and the driving force of the rear wheels determined using the driving force distribution ratio is defined as the excess driving force.

[0177] In the step of redistributing the driving force, a reduction ratio of the driving force exceeding the limit driving force is determined using a turning index, and the determined reduction ratio is applied to the driving force exceeding the limit driving force and transmitted to the driving unit 500 that does not exceed the limit driving force.

[0178] The driving force redistribution unit 350 uses a reduction ratio determined by the turning index to compensate for the driving force that exceeds the limit driving force, thereby satisfying the user's required driving force to the maximum extent possible while maintaining a riding feel according to the driving force distribution ratio set by the user.

[0179] The methods of the present invention may be embodied in the form of program instructions that may be executed by various computing means and stored on computer readable media. The computer readable media may include, alone or in combination with program instructions, data files, data structures, and the like. The program instructions stored on the computer readable media may be those specially designed and constructed for the purposes of the present invention, or they may be well known and available to those skilled in the art of computer software.

[0180] Examples of computer readable media include hardware devices specially configured to store and execute program instructions, such as ROM, RAM, flash memory, etc. Examples of program instructions include high level language codes that can be executed by a computer using an interpreter, etc., as well as machine code produced by a compiler. The above-mentioned hardware devices are configured to operate with at least one software module to perform the operations of the present invention, and vice versa.

[0181] Although the present invention has been described with reference to the embodiments, those skilled in the art will understand that various modifications and variations of the present invention can be made without departing from the spirit and scope of the present invention as set forth in the claims. [Explanation of symbols]

[0182] 100 Input section 200 Receiver 300 Driving force determination unit 310 First driving force distribution ratio determination unit 320 Driving condition judgment unit 330 Second driving force distribution ratio determination unit 340 Third driving force distribution ratio determination unit 350 Driving force redistribution unit 400 Drive control unit 500 Drive unit 510 First Drive Unit 520 Second Drive Unit

Claims

1. an input section for inputting a selected distribution ratio, which is a driving force generation ratio between the front wheels and the rear wheels, selected by a user; A receiving unit that receives vehicle driving information; a driving force determination unit that determines a driving force distribution ratio, which is a generation ratio of driving forces of the front wheels and the rear wheels, and determines the driving forces of the front wheels and the rear wheels using the driving force distribution ratio; and a drive control unit that controls a drive unit that generates a drive force for the vehicle based on the drive force determined by the drive force determination unit; Including, The driving force determination unit is A driving force adjusting device, comprising: a driving force distribution ratio adjusting unit that adjusts the driving force distribution ratio based on the driving information and the selected distribution ratio.

2. the distribution ratio of the driving force includes a distribution ratio of a first driving force, The driving force determination unit is 2. The driving force adjusting device according to claim 1, wherein a first gradient ratio obtained by resetting the selected distribution ratio within a preset initial setting range is determined as the distribution ratio of the driving force.

3. The initial setting range is: Even when the selected distribution ratio is input so that only the front wheels are driven, a range in which the front wheels can be driven is further included by a preset margin range, or 3. The driving force adjusting device according to claim 2, further comprising a range in which the rear wheels can be driven by a preset margin range even when the selected distribution ratio is input so that only the rear wheels are driven.

4. The drive unit is 2. The driving force adjusting device according to claim 1, comprising: a first driving unit that generates a driving force to at least one of the front wheels or the rear wheels of the vehicle; and a second driving unit that generates a driving force to the other of the front wheels or the rear wheels of the vehicle.

5. the distribution ratio of the driving force includes a distribution ratio of a second driving force, The driving force determination unit is 2. The driving force adjusting device according to claim 1, further comprising: a first additional distribution ratio determined in consideration of a friction coefficient of a road surface on which the vehicle is traveling and the selected distribution ratio; and the first additional distribution ratio is further applied to the distribution ratio of the driving force.

6. The driving force distribution ratio further includes a third driving force distribution ratio, 2. The driving force adjusting device of claim 1, wherein the third driving force distribution ratio is determined by further applying a second additional distribution ratio in response to occurrence of understeer or oversteer of the vehicle to the driving force distribution ratio.

7. When understeer of the vehicle occurs, The second additional allocation ratio is 7. The driving force adjusting device according to claim 6, wherein the driving force is determined according to an understeer index (US Index) indicating a degree of understeer occurring within a preset limit additional distribution ratio.

8. When the vehicle oversteers, The second additional allocation ratio is 7. The driving force adjusting device of claim 6, wherein the weighting factor is determined by taking into consideration at least one of an OS Index indicating a degree of oversteer, a friction coefficient of a road surface on which the vehicle is traveling, and the selected distribution ratio.

9. The driving unit includes a first driving unit that generates a driving force to at least one of front wheels or rear wheels of the vehicle, and a second driving unit that generates a driving force to the other of the front wheels or rear wheels of the vehicle, The driving force determination unit is 2. The driving force adjusting device of claim 1, further comprising a driving force redistributor that adjusts the driving force of the first driving unit and the driving force of the second driving unit, which are distributed based on the driving force distribution ratio, and redistributes the adjusted driving force to the first driving unit and the second driving unit.

10. When a wheel slip exceeding an allowable wheel slip occurs in one of the first driving unit and the second driving unit, The driving force redistribution unit includes:

10. The driving force adjusting device of claim 9, wherein the driving force distributed to one of the first driving unit and the second driving unit when wheel slip exceeding an allowable wheel slip occurs is reduced, and the reduced driving force is redistributed to the other of the first driving unit and the second driving unit.

11. The occurrence of wheel slip exceeding the allowable wheel slip is determined by: A wheel slip error is determined based on the magnitude of the received wheel slip exceeding the target wheel slip, and is determined based on whether the wheel slip error exceeds a preset wheel slip; 11. The driving force adjusting device according to claim 10, wherein the target wheel slip is a wheel slip required for the vehicle to travel a target route.

12. The target wheel slip is set separately for the front wheels and the rear wheels; When the selected distribution ratio is set to be larger for the front wheels than for the rear wheels, the target wheel slip for the front wheels is set to be even larger, 12. The driving force adjusting device according to claim 11, wherein when the selected distribution ratio is set to be larger for the rear wheels than for the front wheels, the target wheel slip for the rear wheels is set to be larger.

13. When the driving force of the first driving unit or the driving force of the second driving unit allocated based on the allocation ratio of the driving forces exceeds the limit driving force of the first driving unit or the second driving unit, The driving force redistribution unit includes: redistributing the excess driving force of the first driving unit or the second driving unit that exceeds the limit driving force to the first driving unit or the second driving unit that does not exceed the limit driving force; The driving force adjusting device according to claim 9, wherein the limit driving force is a maximum driving force that can be generated by the first driving unit or the second driving unit.

14. The driving force redistribution unit includes: The driving force adjusting device of claim 13, further comprising: a reduction ratio for the excess driving force based on a turning index; and a driving force obtained by reducing the excess driving force using the reduction ratio is redistributed to the first driving unit or the second driving unit that does not exceed the limit driving force.

15. inputting a selected distribution ratio, which is a ratio of driving force generation between the front wheels and the rear wheels selected by a user; receiving vehicle driving information; a driving force determination step of determining a driving force distribution ratio, which is a generation ratio of driving forces of the front wheels and the rear wheels, and determining the driving forces of the front wheels and the rear wheels using the driving force distribution ratio; and generating driving forces on front and rear wheels based on the determined driving force; Including, The driving force determining step includes: A method for adjusting a driving force distribution ratio, comprising adjusting the driving force distribution ratio based on the driving information and the selected distribution ratio.

16. The driving information is The method for adjusting the driving force according to claim 15, characterized in that the information includes a driver's request torque, wheel slip information, vehicle speed information, steering angle, friction coefficient of the road surface during driving, yaw rate, and yaw acceleration.

17. The driving force determining step includes: determining a first gradient ratio, which is a reset value of the selected distribution ratio within a preset initial setting range, as the distribution ratio of the driving force; 16. The method for adjusting driving force according to claim 15, wherein the initial setting range is set in consideration of a preset margin distribution ratio of the front wheels or the rear wheels.

18. The driving force determining step includes: The driving force adjusting method of claim 15, further comprising determining a first additional distribution ratio in consideration of a friction coefficient of a road surface on which the vehicle is traveling and the selected distribution ratio, and further applying the first additional distribution ratio to the distribution ratio of the driving force.

19. The driving force determining step includes:

16. The method of claim 15, further comprising: determining the driving force distribution ratio by further applying a second additional distribution ratio that is determined differently depending on whether the vehicle is understeered or oversteered.

20. When the amount of wheel slip occurring in the vehicle or the driving force required exceeds the limit driving force of the front or rear wheels, 16. The method of claim 15, further comprising the step of redistributing the driving force between the front wheels and the rear wheels by adjusting the driving force between the front wheels and the rear wheels distributed based on the distribution ratio of the driving force.

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