Apparatus and method for controlling slip rate of vehicle

Abstract

The invention relates to an apparatus and a method for controlling a slip rate of a vehicle. The apparatus includes a vehicle information receiver configured to receive off-road driving information of a vehicle, a target slip rate estimation unit configured to estimate a target slip rate of the vehicle, and a storage unit configured to store the target slip rate. The target slip rate estimation unit is configured to estimate a wheel slip rate interval corresponding to a maximum traction coefficient as a target slip rate value using the off-road driving information, and the storage unit is configured to store the target slip rate value.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority to patent application No. 10-2023-0149316, filed on November 1, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to an apparatus and a method for controlling the slip ratio of a vehicle. Background Art

[0004] Recently, the number of people who enjoy driving on off-road surfaces such as sand, mud, gravel, etc. has been increasing. In addition, the rising interest in off-road vehicles is driven by an increasing number of vehicle orders from many overseas countries where off-road surfaces dominate the country's road network.

[0005] On the other hand, there are various off-road (terrain) roads, such as snow roads, ice roads, sand roads, mud roads, etc., and roads with various characteristics can also be changed according to seasons such as spring, summer, autumn, and winter. In addition, wheel slip often occurs on such off-road roads, and the characteristics of such slip can change according to changes in the road surface.

[0006] However, the driving control technology for each terrain mode according to the prior art only controls the motor torque based on a limited predetermined mode. This control technology faces many problems because it cannot adapt to the changing road conditions in various ways. Summary of the invention

[0007] One aspect of the present invention is to provide an apparatus and method that enables a vehicle traveling on or off-road to cope with wheel slip conditions regardless of the type or characteristics of the terrain surface.

[0008] In addition, another aspect of the present invention is to provide an apparatus and method that enables a vehicle traveling on or off-road to achieve optimal traction performance according to road conditions.

[0009] According to another aspect of the present invention, there is provided an apparatus for controlling a slip ratio of a vehicle. The apparatus comprises: a vehicle information receiver configured to receive off-road driving information of the vehicle; and a target slip ratio estimation unit configured to estimate a wheel slip ratio interval corresponding to a maximum traction coefficient as a target slip ratio value based on the off-road driving information. In addition, the apparatus comprises a storage unit configured to store the target slip ratio value.

[0010] The target slip ratio estimation unit is configured to estimate a target slip ratio value based on off-road running information when the vehicle is accelerating.

[0011] The target slip ratio estimating unit may be configured to determine that the vehicle is in an accelerating state when a value obtained by subtracting a wheel speed from a vehicle speed is a positive number.

[0012] The target slip ratio estimation unit is configured to repeatedly calculate the traction coefficient and the wheel slip ratio at a set time or a set interval using the off-road driving information collected by the vehicle information receiver. The target slip ratio estimation unit may be configured to estimate the wheel slip ratio interval corresponding to the maximum traction coefficient based on the traction coefficient information corresponding to each wheel slip ratio.

[0013] The traction coefficient may be a value calculated by dividing the wheel driving force calculated using the off-road driving information collected by the vehicle information receiver by the wheel vertical force.

[0014] The wheel slip ratio may be calculated using the wheel speed and the vehicle speed collected by the vehicle information receiver.

[0015] The storage unit may be configured to store the target slip ratio value when the vehicle is in a deceleration state.

[0016] The storage unit may be configured to store the target slip ratio value when braking is applied to the vehicle.

[0017] According to another aspect of the present invention, a method for controlling a slip ratio of a vehicle is provided. The method comprises: receiving off-road driving information of the vehicle; estimating a wheel slip ratio interval corresponding to a maximum traction coefficient as a target slip ratio value based on the off-road driving information. The method further comprises storing the target slip ratio value.

[0018] The method for controlling a slip ratio of a vehicle may further include determining whether the vehicle is in a vibrating state before estimating the target slip ratio value.

[0019] When the vehicle is accelerating in a vibrating state, estimating the target slip ratio value is performed.

[0020] Determining whether the vehicle is in a vibrating state includes determining that the vehicle is accelerating when a vehicle speed is greater than a wheel speed.

[0021] Estimating the target slip ratio value may include: using off-road driving information collected by a vehicle information receiver to repeatedly calculate the traction coefficient and the wheel slip ratio at a set time or a set interval; and estimating the wheel slip ratio range corresponding to the maximum traction coefficient based on the traction coefficient information corresponding to each wheel slip ratio.

[0022] The method for controlling a slip ratio of a vehicle may further include determining whether to store the target slip ratio value before storing the target slip ratio value.

[0023] Determining whether to store the target slip ratio value includes storing the target slip ratio value when the vehicle is in a deceleration state.

[0024] Determining whether to store the target slip ratio value includes storing the target slip ratio value when braking is applied to the vehicle.

[0025] The method of controlling the slip ratio of a vehicle according to the embodiment may be stored in a non-volatile computer-readable storage medium storing computer-readable instructions. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and other aspects, features and advantages of the present invention will be more clearly understood from the following detailed description presented in conjunction with the accompanying drawings, in which:

[0027] Figure 1 is a conceptual diagram of an apparatus for controlling a slip ratio of a vehicle according to an embodiment;

[0028] Figure 2 is a conceptual diagram showing an example of a vehicle information receiver in a control device according to an embodiment;

[0029] Figure 3 is a conceptual diagram showing an example of a target slip ratio estimating unit in the control device according to the embodiment;

[0030] Figure 4 is a reference diagram illustrating a method of calculating an axle load of a vehicle according to an embodiment;

[0031] Figure 5 is a schematic diagram showing an example of estimating a target slip ratio in a control device according to an embodiment;

[0032] Figure 6 is a conceptual diagram of a method for controlling a slip ratio of a vehicle according to an embodiment;

[0033] Figure 7 is a detailed conceptual diagram showing a method for controlling a slip ratio of a vehicle according to an embodiment;

[0034] Figure 8 is a conceptual diagram showing an example of a target slip ratio estimating operation in the control method according to the embodiment. DETAILED DESCRIPTION

[0035] Since the present invention can make various changes and have various embodiments, specific embodiments are shown in the drawings and described in detail below. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all changes, equivalents and substitutions included in the spirit and technical scope of the present invention.

[0036] For example, terms such as first, second, etc. can be used to describe various components, but components should not be limited by these terms. The above terms are only used to distinguish one component from another component. For example, a first component can be named a second component, and similarly, a second component can also be named a first component without departing from the scope of the present invention. The term "and / or" includes any combination or any one of a plurality of related statement items.

[0037] The terms used in the present invention are only used to describe specific embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly stipulates otherwise. In the present invention, terms such as "comprise", "include" and "have" are intended to specify the presence of features, quantities, steps, operations, components, parts or combinations thereof described in the specification. It should be understood that this does not preclude the presence or addition of one or more other features, quantities, steps, operations, components, parts or combinations thereof.

[0038] Unless otherwise defined, all terms (including technical or scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless clearly defined in the present invention.

[0039] When a controller, component, device, element, part, unit, module, etc. of the present invention is described as having a purpose or performing an operation, function, etc., the controller, component, device, element, part, unit or module should be considered herein as "configured to" meet the purpose or perform the operation or function. Each controller, component, device, element, part, unit, module, etc. can be implemented or include a processor and a memory (e.g., a non-volatile computer-readable medium) as part of the device.

[0040] In this specification, a vehicle refers to various means of transportation that moves a transported object (eg, a person, an animal, a cargo, etc.) from a starting point to a destination. The vehicle is not limited to a means of transportation that travels on roads or tracks.

[0041] Hereinafter, embodiments are described in more detail with reference to the accompanying drawings.

[0042] refer to Figures 1 to 8, the apparatus 100 for controlling the slip rate of a vehicle or the method for controlling the slip rate of a vehicle (S100) of the embodiment can be a slip control logic (device or method) based on wheel driving force, wheel vertical force and wheel slip rate to ensure maximum traction for each off-road terrain surface. According to the embodiment, whenever wheel slip occurs, the slip rate that can apply maximum traction is monitored and updated, regardless of the type or characteristics of the terrain surface. Therefore, the best traction performance for each terrain surface can be obtained.

[0043] Below, first refer to Figure 1 The apparatus 100 for controlling the slip ratio is described, and the control method (S100) is described later.

[0044] Figure 1 is a conceptual diagram of an apparatus for controlling a slip ratio of a vehicle according to an embodiment.

[0045] The apparatus 100 for controlling the slip rate of a vehicle (eg, an electric vehicle) according to an embodiment may be an auxiliary device that allows a vehicle system to select a maximum traction force according to the slip rate for each road surface. Hereinafter, a vehicle may refer to any object traveling on a terrain road, including an electric vehicle.

[0046] A vehicle traveling on a road or off-road may control a target slip ratio interval that may ensure maximum traction regardless of the type or characteristics of the terrain surface. Specifically, off-road oscillation data of the vehicle may be analyzed, a slip ratio interval in which maximum traction is applied may be estimated, and a corresponding slip ratio may be stored as a target slip ratio. Thereafter, the stored target slip ratio may be used for driving control of the vehicle.

[0047] The apparatus 100 for controlling a slip ratio of a vehicle according to the embodiment may include a vehicle information receiver 110 , a target slip ratio estimating unit 120 , and a storage unit 130 .

[0048] exist Figures 1 to 8 The control unit is omitted in the embodiment, but in the embodiment, a control unit may be provided, the control unit controls the apparatus 100 for controlling the slip rate of the vehicle and the method (S100) for controlling the slip rate of the vehicle, and the overall control may be obtained by the control unit. For example, the control unit may be connected to the apparatus 100 for controlling the slip rate of the vehicle. In addition, the control unit may be connected to the vehicle information receiver 110, the target slip rate estimation unit 120, and the storage unit 130 to participate in the control of these configurations.

[0049] refer to Figure 2The vehicle information receiver 110 may receive (collect) necessary information from a target slip ratio estimation unit 120 and a storage unit 130 which will be described below. The vehicle information receiver 110 may include a traction coefficient estimation data receiver 111 and a wheel slip ratio calculation data receiver 115.

[0050] The traction coefficient estimation data receiver 111 may include data for calculating (estimating) the wheel driving force and data for calculating (estimating) the wheel vertical force.

[0051] For example, in order to determine whether the vehicle is vibrating, such information as the value of an accelerator position sensor (APS), vehicle speed, wheel speed, etc. may be collected (received).

[0052] In addition, in order to calculate the wheel driving force, such information as the motor torque (T M ), reduction ratio (FGR), friction coefficient (u), wheel (tire) radius (R), drive system inertia moment, wheel angular acceleration, etc. In addition, in order to estimate the wheel vertical force, such information as total axle load (F z ), the axle load of the front wheel of the vehicle (F Z，f ), the axle load of the rear wheel of the vehicle (F Z，r ), vehicle weight (m b ), the distance from the center of gravity of the vehicle to the rear axle (l r ), the distance from the center of gravity of the vehicle to the front axle (l f ), gravitational acceleration, height of the vehicle's center of gravity (h CG ), the longitudinal acceleration of the vehicle (ba x )wait.

[0053] Furthermore, in order to calculate the wheel slip rate, information such as the vehicle speed and the wheel speed may be acquired.

[0054] The values ​​of the wheel torque, wheel slip rate, etc. described above can be measured or calculated using various sensors installed in the vehicle and various algorithms provided in the vehicle. Such sensors include speed sensors, rotation sensors, acceleration sensors, and angular velocity sensors. Tools, sensors, and methods other than those described above can be used, and there is no limitation on the measurement or calculation method.

[0055] Next, refer to Figure 3 The target slip ratio estimation unit 120 may estimate the wheel slip ratio interval corresponding to the maximum traction coefficient as the target slip ratio value based on the traction coefficient (T) calculated (estimated) in the traction coefficient calculation unit 121 and the wheel slip ratio value calculated (estimated) in the wheel slip ratio calculation unit 125.

[0056] For example, Figure 5 As shown, the traction coefficient and the wheel slip ratio are repeatedly calculated at a set time or interval. In addition, by estimating the wheel slip ratio interval corresponding to the maximum traction coefficient based on the traction coefficient information corresponding to the corresponding wheel slip ratio, the corresponding wheel slip ratio interval can be estimated as the target slip ratio value ( Figure 5 Specifically, for the wheel slip ratio repeatedly calculated when the vehicle is in a vibrating state, the device calculates the portion with the largest traction coefficient. Specifically, the target slip ratio when the traction force of the vehicle is the largest can be stored.

[0057] The target slip ratio estimation unit 120 may include a traction coefficient calculation unit 121 and a wheel slip ratio calculation unit 125. In addition, the embodiment may include a vibration determination unit that determines whether the vehicle is in a vibration (start-off) state. The vibration determination unit may be included in the target slip ratio estimation unit 120, or may be provided as a separate component, and the target slip ratio estimation unit 120 may be instructed to calculate (estimate) a target slip ratio value only when the vehicle is in a vibration state.

[0058] The vibration determination unit may determine whether the vehicle is in a vibration state. For example, a case where it is determined that the vehicle is accelerating may be identified as a case where the vehicle is in a vibration state. In addition, when the vehicle speed is greater than the wheel speed, the vibration determination unit may determine acceleration. In addition, when the value of the accelerator position sensor (APS) is a positive number, the vehicle speed is a positive number, and the vehicle speed is greater than the wheel speed, the vibration determination unit may determine that the vehicle is in a vibration state.

[0059] Furthermore, when the vibration determination unit determines that the vehicle is not in a vibration state, the target slip ratio estimation unit 120 may be instructed to calculate (estimate) a target slip ratio value only when the vehicle is in a vibration state by repeatedly collecting vehicle information again.

[0060] The traction coefficient calculation unit 121 may calculate (estimate) the traction coefficient (T) by estimating (calculating) the wheel driving force and the wheel vertical force.

[0061] The wheel driving force of the front and rear wheels of the vehicle (F x，f 、F x，r ) can be calculated, for example, by the following [Equation 1].

[0062] [Equation 1]

[0063] F x，f =(T M,f ×FGR f +i f × f ) / R

[0064] F x，r =(T M,r ×FGR r +i r × r ) / R

[0065] In Equation 1, T M，F is the front wheel motor torque, FGR f is the front wheel final reduction ratio (reduction ratio), i f is the moment of inertia of the front-wheel drive system, w f is the front wheel angular acceleration, R is the tire dynamic diameter, T M，r is the rear wheel motor torque, FGR r is the final reduction ratio (reduction ratio) of the rear wheels, i r is the moment of inertia of the rear-wheel drive system, w r is the rear wheel angular acceleration.

[0066] The vertical wheel forces (F z，f 、F z，r ) (e.g., axle load) can be calculated by, for example, the following [Equation 2].

[0067] [Equation 2]

[0068]

[0069]

[0070] In Equation 2, F z，f is the axle load of the front wheel, F z，r is the axle load of the rear wheel, m b is the weight of the vehicle, l r is the distance from the center of gravity to the rear axle, l f is the distance from the center of gravity to the front axle, g is the acceleration due to gravity, h CG is the height of the center of gravity, ba x is the longitudinal acceleration of the vehicle.

[0071] exist Figure 4 In the example, COG is the center of gravity, ba y Corresponds to the lateral acceleration of the vehicle.

[0072] Using the above information, the traction coefficient calculation unit 121 can calculate (estimate) the traction coefficients of the front and rear wheels of the vehicle (traction coefficient T r，f , T r，r ).

[0073] [Equation 3]

[0074] Tr，f =F x，f / F z，f

[0075] T r，r =F x，r / F z，r

[0076] The wheel slip ratio calculation unit 125 can calculate (estimate) the wheel slip ratios Wr of the two front wheels and the two rear wheels respectively by using the vehicle speed and the wheel speed through the following equation 4: f，l , Wr f，r , Wr r，l and Wr r，r .

[0077] [Equation 4]

[0078] W f，l =(V f，l -V abs ) / V f，l ×100

[0079] W f，r =(V f，r -V abs ) / V f，r ×100

[0080] W r，l =(V r，l -V abs ) / V r，l ×100

[0081] W r，r =(V r，r -V abs ) / V r，r ×100

[0082] In Equation 4, Wr f，l , Wr f，r , Wr r，l and Wr r，r are the wheel slip rates of the left front wheel, right front wheel, left rear wheel, and right rear wheel respectively. f，l 、V f，r 、V r，l and V r，r are the wheel speeds of the left front wheel, right front wheel, left rear wheel, and right rear wheel, respectively. In addition, V abs is the vehicle speed (i.e., the absolute speed of the vehicle in kph), and wheel speed is the linear speed of the wheels in kph.

[0083] In this way, for example, the target slip ratio can be calculated using the traction coefficient (T) and the wheel slip ratio (W r) to select, the traction coefficient (T) and wheel slip ratio (W r ) is calculated at fixed times or intervals using equations 1 to 4. For example, the target slip ratio estimation unit 120 may estimate a wheel slip ratio interval corresponding to the maximum traction coefficient as a target slip ratio value based on the traction coefficient (T) calculated (estimated) in the traction coefficient calculation unit 121 and the wheel slip ratio value calculated (estimated) in the wheel slip ratio calculation unit 125.

[0084] For example, Figure 5 As shown, the traction coefficient and wheel slip ratio are repeatedly calculated at a set time or interval. In addition, the wheel slip ratio interval corresponding to the maximum traction coefficient can be estimated based on the traction coefficient information corresponding to the corresponding wheel slip ratio, and the corresponding wheel slip ratio interval can be estimated as the target slip ratio value ( Figure 5 Specifically, for the wheel slip ratios repeatedly calculated when the vehicle is in a vibrating state, the portion with the largest calculated traction coefficient (eg, the target slip ratio when the maximum vehicle traction force can be applied) can be stored.

[0085] Next, the storage unit 130 may store the portion when the calculated traction coefficient is maximum (e.g., the target slip ratio when the maximum traction force of the vehicle can be applied) in the target slip ratio estimation unit 120. In addition, the apparatus 100 for controlling the slip ratio of the vehicle may be provided with a storage determination unit to determine whether to store the target slip ratio. The storage determination unit may be included in the target slip ratio estimation unit 120 or the storage unit 130, or may be provided as a configuration separate from them. In addition, the target slip ratio value may be stored in the storage unit 130 only when the vehicle is in a predetermined state.

[0086] For example, when the vehicle is in a deceleration state, a command may be given to store the target slip ratio value in the storage unit 130. Also, for example, when the brakes are applied to the vehicle, the target slip ratio value may be commanded to be stored. Also, when the vehicle speed is a specific speed, for example, 1 to 10 kph (km / h) or less (specifically, for example, 1 km / h or less) and the brakes are applied to the vehicle, the target slip ratio value may be commanded to be stored.

[0087] On the other hand, when the storage determination unit determines that the target slip ratio value is not in a state to be stored in the storage unit 130, the target slip ratio value may be updated again by the vehicle information receiver 110 and the target slip ratio estimation unit 120. Specifically, the target slip ratio value may be updated by continuously calculating the slip ratio at which the traction force of the vehicle may be maximized over time. At the moment when the storage determination unit instructs the storage unit 130 to store the target slip ratio value, a value corresponding to the target slip ratio value may be stored in the storage unit 130.

[0088] Next, a method for controlling a slip ratio of a vehicle ( S100 ) is described, which may be implemented using at least a portion of the apparatus 100 for controlling a slip ratio of a vehicle described above.

[0089] Figure 6 is a conceptual diagram of a method for controlling a slip ratio of a vehicle according to an embodiment. Figure 7 is a detailed conceptual diagram illustrating a method for controlling a slip ratio of a vehicle according to an embodiment. Figure 8 is a conceptual diagram showing an example of a target slip ratio estimating operation in the control method according to the embodiment.

[0090] refer to Figure 6 , the method ( S100 ) for controlling the slip ratio of a vehicle according to the embodiment may include a vehicle information receiving operation ( S110 ), a target slip ratio estimating operation ( S120 ), and a storing operation ( S130 ).

[0091] In addition, reference Figure 7 The method (S100) for controlling the slip ratio of a vehicle may further include a vibration determination operation (S119) to determine whether the vehicle is vibrating when, for example, proceeding from the vehicle information receiving operation (S110) to the target slip ratio estimating operation (S120). In addition, the method (S100) may further include a storage determination operation (S129) to determine whether to store the target slip ratio when, for example, proceeding from the target slip ratio estimating operation (S120) to the storing operation (S130).

[0092] The control unit is omitted in the drawings, but in an embodiment, a control unit may be provided, the control unit controlling the device 100 for controlling the slip rate of the vehicle and the method (S100) for controlling the slip rate of the vehicle, and the overall control may be obtained by the control unit. For example, the control unit may be related to controlling the method (S100) for controlling the slip rate of the vehicle. Specifically, the control unit may be related to the control of the vehicle information receiving operation (S110), the target slip rate estimation operation (S120), the storage operation (S130), the vibration determination operation (S119) and / or the storage determination operation (S129). The control unit may participate in the control of these configurations by connecting to the vehicle information receiver 110, the target slip rate estimation unit 120, and the storage unit 130 related to the control thereof.

[0093] The method ( S100 ) for controlling the slip ratio of a vehicle may be performed by the above-mentioned apparatus 100 for controlling the slip ratio of a vehicle. In addition, respective individual operations may be performed by the vehicle information receiver 110 , the target slip ratio estimating unit 120 , and the storage unit 130 .

[0094] The vehicle information receiving operation (S110) may receive information required in the target slip ratio estimating operation (S120) and the storing operation (S130) described below. The data received in the vehicle information receiving operation (S110) may include traction coefficient estimation data and wheel slip ratio calculation data. The vehicle information receiving operation (S110) may be performed by the vehicle information receiver 110.

[0095] The traction coefficient estimation data may include data for calculating (estimating) the wheel driving force and data for calculating (estimating) the wheel vertical force.

[0096] For example, to determine whether the vehicle is vibrating, such information as the value of an accelerator position sensor (APS), vehicle speed, and wheel speed may be received (collected).

[0097] In addition, in order to calculate the wheel driving force, such information as the motor torque (T M ), reduction ratio (FGR), friction coefficient (u), wheel (tire) radius (R), drive system inertia moment, wheel angular acceleration, etc. In addition, in order to estimate the wheel vertical force, such information as total axle load (F z ), the axle load of the front wheel of the vehicle (F Z，f ), the axle load of the rear wheel of the vehicle (F Z，r ), vehicle weight (m b ), the distance from the center of gravity of the vehicle to the rear axle (l r ), the distance from the center of gravity of the vehicle to the front axle (lf ), gravitational acceleration, height of the vehicle's center of gravity (h CG ), the longitudinal acceleration of the vehicle (ba x )wait.

[0098] Furthermore, in order to calculate the wheel slip rate, information such as the vehicle speed and the wheel speed may be acquired.

[0099] The values ​​of the wheel torque, wheel slip rate, etc. described above may be measured or calculated using various sensors installed in the vehicle and various algorithms installed in the vehicle, such as speed sensors, rotation sensors, acceleration sensors, angular velocity sensors, etc. Tools, sensors, and methods other than those described above may be used, and there is no limitation on the measurement or calculation method.

[0100] The target slip ratio estimation operation (S120) may include traction coefficient calculation and wheel slip ratio calculation. In addition, the embodiment may include a vibration determination operation (S119) of determining whether the vehicle is in a vibration state. The target slip ratio estimation operation (S120) may be performed by the target slip ratio estimation unit 120.

[0101] The vibration determination operation (S119) is an intermediate operation for proceeding from the vehicle information receiving operation (S110) to the target slip ratio estimating operation (S120). In addition, only when the vehicle is in a vibration state, a command can be given to perform the target slip ratio estimating operation (S120) and calculate (estimate) the target slip ratio value. The vibration determination operation (S119) can be performed by the control unit using information from the vehicle information receiver 110.

[0102] The vibration determination operation (S119) determines whether the vehicle is in a vibration state, and only when the vehicle is in a vibration state (Y), the next operation, i.e., the target slip ratio estimation operation (S120), can be performed. For example, a situation in which it is determined that the vehicle is accelerating can be identified as a situation in which the vehicle is in a vibration state. In addition, in the vibration determination operation (S119) (for example, when the vehicle speed is greater than the wheel speed), acceleration can be determined. In addition, in the vibration determination operation (S119) (for example, when the value of the accelerator position sensor (APS) is positive, the vehicle speed is positive, and the vehicle speed is greater than the wheel speed), it can be determined that the vehicle is in vibration.

[0103] In addition, when it is determined in the vibration determination operation (S119) that the vehicle is not in the vibration state (N), the vehicle information receiving operation (S110) may be repeated again. For example, the vehicle information is received again repeatedly in the vehicle information receiving operation (S110), and only when it is determined based on the received information that the vehicle is in the vibration state, a command may be given to perform the target slip ratio estimation operation (S120) and calculate (estimate) the target slip ratio value.

[0104] In the target slip ratio estimation operation (S120), the target slip ratio value may be estimated using the traction coefficient (T) calculated (estimated) in the traction coefficient calculation and the wheel slip ratio value calculated (estimated) in the wheel slip ratio calculation. The target slip ratio value is a wheel slip ratio interval corresponding to the maximum traction coefficient. The target slip ratio estimation operation (S120) may be performed by the target slip ratio estimation unit 120.

[0105] For example, as referenced above Figure 5 As described above, the traction coefficient and the wheel slip ratio are repeatedly calculated at a fixed time or interval. In addition, by estimating the wheel slip ratio interval corresponding to the maximum traction coefficient based on the traction coefficient information corresponding to each wheel slip ratio, the corresponding wheel slip ratio interval can be estimated as the target slip ratio value ( Figure 5 Specifically, for the wheel slip ratio repeatedly calculated when the vehicle is in a vibrating state, the device calculates the portion where the traction coefficient is the largest. In other words, the target slip ratio when the traction force of the vehicle is the largest can be stored.

[0106] refer to Figure 8 , the target slip ratio estimating operation (S120) may include a traction coefficient calculating operation (S121, S122, and S123) and a wheel slip ratio calculating operation (S124).

[0107] The traction coefficient (T) can be calculated (estimated) by estimating (calculating) the wheel driving force and the wheel vertical force.

[0108] The wheel driving force of the front and rear wheels of the vehicle (F x，f 、F x，r ) can be calculated by [Equation 1] mentioned above.

[0109] The vertical wheel forces (F z，f 、F z，r ) (e.g., axle load) can be calculated by [Equation 2] mentioned above.

[0110] Using the above information, the traction coefficients (T r，f ,、T r，r ) can be calculated (estimated) using [Equation 3] mentioned above.

[0111] In addition, the wheel slip ratios (Wr f，l , Wr f，r , Wr r，l , Wr r，r ) can be calculated (estimated) separately by using the vehicle speed and wheel speed through the above-mentioned [Equation 4].

[0112] In this way, the target slip ratio can be calculated using the traction coefficient (T) and wheel slip ratio (W r ) to select, the traction coefficient (T) and wheel slip ratio (W r ) is calculated at fixed times or intervals using equations 1 to 4. For example, the target slip ratio estimating operation (S120) may estimate a target slip ratio value, i.e., a wheel slip ratio interval corresponding to the maximum traction coefficient, using the traction coefficient (T) calculated (estimated) in the traction coefficient calculating operation and the wheel slip ratio value calculated (estimated) in the wheel slip ratio calculation.

[0113] For example, Figure 5 As shown, the traction coefficient and wheel slip ratio are repeatedly calculated at a set time or interval. In addition, by estimating the wheel slip ratio interval corresponding to the maximum traction coefficient based on the traction coefficient information corresponding to each wheel slip ratio, the corresponding wheel slip ratio interval can be estimated as the target slip ratio value ( Figure 5 Specifically, for the wheel slip ratio repeatedly calculated when the vehicle is in a vibrating state, the device calculates the portion where the traction coefficient is the largest. In other words, the target slip ratio when the traction force of the vehicle is the largest can be stored.

[0114] Next, in the storage operation (S130), a portion when the traction coefficient is calculated to be maximum in the target slip ratio estimating operation (S120) (i.e., a target slip ratio that can maximize the traction of the vehicle) may be stored. In addition, the method (S100) for controlling the slip ratio of the vehicle may include a storage determination operation (S129) to determine whether to store the target slip ratio. The storage operation (S130) may be performed by the storage unit 130.

[0115] The storage determination operation (S129) is an intermediate operation from the target slip ratio estimation operation (S120) to the storage operation (S130). Only when the vehicle is in a predetermined state, a command can be given to perform the storage operation (S130) and store the target slip ratio value. The storage determination operation (S129) can be performed by the control unit using information from the target slip ratio estimation unit 120.

[0116] The storage determination operation (S129) determines whether the vehicle is in a predetermined state, and only when it is appropriate (Y), can it proceed to the next operation, that is, the storage operation (S130). For example, when the vehicle is in a deceleration state, the storage operation (S130) can be performed, and a command can be given to store the target slip ratio value. In addition, when the brakes are applied to the vehicle, a command can be given to perform the storage operation (S130) and store the target slip ratio value. In addition, when the speed of the vehicle is set to a certain speed (for example, 1 to 10 kph (km / h) or lower), and when the brakes are applied to the vehicle, the device proceeds to the storage operation (S130), and a command can be given to store the target slip ratio value.

[0117] In addition, when it is determined in the storage determination operation (S129) that the target slip ratio value is not in a state to be stored in the storage unit 130 (N), the target slip ratio value may be updated again in the vehicle information receiving operation (S110) and the target slip ratio estimating operation (S120). Specifically, the target slip ratio value may be updated by continuously calculating the slip ratio at which the traction force of the vehicle can be maximized over time. Then, the system may proceed from the storage determination operation (S129) to the storage operation (S130), and at the moment when the target slip ratio value is commanded to be saved, the storage operation (S130) may be performed.

[0118] Therefore, at the storing operation 130, the target slip ratio (i.e., the target slip ratio interval that can ensure the maximum traction) can be stored regardless of the type or characteristics of the terrain surface that the off-road vehicle is traveling on. Therefore, the stored target slip ratio can be used to control the vehicle's travel on various terrain surfaces with various characteristics.

[0119] The method according to the embodiment of the present invention can be implemented in the form of program instructions, which can be executed by various computer devices and can be recorded on a computer-readable medium. The computer-readable medium can include program instructions, data files, data structures, etc., alone or in combination. The program instructions recorded on the computer-readable medium can be specially designed and configured for the present invention, or can be known and available to those skilled in the art of computer software.

[0120] Examples of computer-readable media include hardware devices specifically configured to store and execute program instructions, such as read-only memory (ROM), random access memory (RAM), flash memory, etc. Examples of program instructions include high-level language codes that can be executed by a computer using an interpreter, and machine language codes (e.g., codes generated by a compiler). The above-mentioned hardware devices can be configured to run together with at least one software module to perform the operations of the present invention, and vice versa.

[0121] The device 100 for controlling the slip rate of a vehicle (electric vehicle) according to the embodiment may include a storage unit. The storage unit is a recording medium suitable for storing the device 100 for controlling the slip rate of a vehicle (electric vehicle), and may include magnetic media such as a hard disk, a floppy disk, and a magnetic tape, optical media such as a compact disk read-only memory (CD-ROM) and a digital video disk (DVD), magneto-optical media such as a floppy disk, and semiconductor memories such as flash memory, erasable programmable ROM (EPROM), or SSD manufactured based thereon.

[0122] The storage unit may be implemented by a non-volatile memory (not shown) configured to store data about an algorithm configured to control the operation of various components of the vehicle or reproduce software instructions for the algorithm. In addition, the storage unit may be implemented by a processor (not shown) configured to perform the operations described above or below using data stored in the corresponding memory. In this case, the memory and the processor may be implemented as separate chips. Alternatively, the memory and the processor may be implemented as a single chip integrated with each other. The processor may be in the form of one or more processors.

[0123] The components of the device 100 for controlling the slip rate of a vehicle (electric vehicle) can be connected to exchange information by wired or wireless connection using a network provided in the vehicle. Of course, the method (S100) for controlling the slip rate of a vehicle (electric vehicle) can also exchange information by wired or wireless connection using a network provided in the vehicle. For example, data can be exchanged using a network communication device provided in the vehicle, such as Ethernet, media-oriented system transmission (MOST), Flexray, controller area network (CAN), local interconnect network (LIN), Internet, LTE, 5G, Wi-Fi, Bluetooth, near field communication (NFC), Zigbee, radio frequency (RF), etc.

[0124] As described above, the apparatus and method according to the embodiment can enable a vehicle traveling on or off-road to cope with a wheel slip situation regardless of the type or characteristics of the terrain surface.

[0125] In the apparatus and method according to the embodiment, a vehicle traveling on a road or off-road can achieve optimal traction performance according to the road surface condition.

[0126] While embodiments have been illustrated and described above, it will be apparent to those skilled in the art that modifications and variations may be made without departing from the scope of the invention as defined by the appended claims.

Claims

1. A device for controlling the slip rate of a vehicle, the device comprising: a vehicle information receiver configured to receive off-road driving information of the vehicle; a target slip ratio estimation unit configured to estimate a wheel slip ratio interval corresponding to a maximum traction coefficient as a target slip ratio value based on off-road driving information; as well as The storage unit is configured to store a target slip ratio value.

2. The apparatus for controlling the slip ratio of a vehicle according to claim 1, wherein: The target slip ratio estimation unit is configured to estimate a target slip ratio value based on off-road running information when the vehicle is accelerating.

3. The apparatus for controlling the slip ratio of a vehicle according to claim 2, wherein the target slip ratio estimating unit is configured to determine that the vehicle is in an accelerating state when a value obtained by subtracting a wheel speed from a vehicle speed is a positive number.

4. The apparatus for controlling the slip ratio of a vehicle according to claim 1, wherein: The target slip ratio estimation unit is configured as follows: Using off-road driving information collected by a vehicle information receiver, repeatedly calculating the traction coefficient and the wheel slip rate at a set time or a set interval; Based on the traction coefficient information corresponding to each wheel slip ratio, a wheel slip ratio range corresponding to the maximum traction coefficient is estimated.

5. The apparatus for controlling the slip ratio of a vehicle according to claim 4, wherein: The traction coefficient is a value calculated by dividing the wheel driving force calculated using the off-road running information collected by the vehicle information receiver by the wheel vertical force.

6. The apparatus for controlling the slip ratio of a vehicle according to claim 4, wherein: The wheel slip ratio is calculated using the wheel speed and the vehicle speed collected by the vehicle information receiver.

7. The apparatus for controlling the slip ratio of a vehicle according to claim 1, wherein: The storage unit is configured to store a target slip ratio value when the vehicle is in a deceleration state.

8. The apparatus for controlling the slip ratio of a vehicle according to claim 1, wherein: The storage unit is configured to store a target slip ratio value when braking is applied to the vehicle.

9. A method for controlling a slip ratio of a vehicle, the method comprising: Receiving off-road driving information of the vehicle; estimating a wheel slip ratio interval corresponding to a maximum traction coefficient as a target slip ratio value based on off-road driving information; Stores the target slip value. 10 . The method of claim 9 , further comprising determining whether the vehicle is in a vibrating state before estimating the target slip ratio value.

11. The method according to claim 10, wherein: When the vehicle is accelerating in a vibrating state, estimating the target slip ratio value is performed.

12. The method according to claim 11, wherein: Determining whether the vehicle is in a vibrating state includes determining that the vehicle is accelerating when a vehicle speed is greater than a wheel speed.

13. The method according to claim 9, wherein: Estimated target slip ratio values ​​include: Using off-road driving information collected by a vehicle information receiver, repeatedly calculating the traction coefficient and the wheel slip rate at a set time or a set interval; Based on the traction coefficient information corresponding to each wheel slip ratio, a wheel slip ratio range corresponding to the maximum traction coefficient is estimated.

14. The method according to claim 9, further comprising: Whether to store the target slip ratio value is determined before storing the target slip ratio value.

15. The method according to claim 14, wherein: Determining whether to store the target slip ratio value includes storing the target slip ratio value when the vehicle is in a deceleration state.

16. The method according to claim 14, wherein: Determining whether to store the target slip ratio value includes storing the target slip ratio value when braking is applied to the vehicle.

17. A non-volatile computer-readable storage medium having computer-readable instructions stored thereon, which when executed by a processor cause the processor to: Receiving off-road driving information of the vehicle; estimating a wheel slip ratio interval corresponding to a maximum traction coefficient as a target slip ratio value based on off-road driving information; Stores the target slip value.

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