Vehicle driving assistance method and driving assistance unit

Abstract

The embodiment of the invention provides a vehicle driving assistance method and a driving assistance unit. The driving assistance unit comprises a first detection module configured to detect whether each wheel is a stable wheel or a non-stable wheel based on the slip rate of each wheel so as to obtain a first detection result; the second detection module is configured to detect whether each wheel suspension is in a compressed state or a stretched state based on the suspension stroke of each wheel and detect an acceleration difference value between the actual acceleration and the calculated acceleration of the vehicle so as to obtain a second detection result; and a decision module configured to determine a driving assistance strategy according to the first detection result and the second detection result.

Description

Technical Field

[0001] The present invention generally relates to the technical field of vehicle driving assistance, and in particular to a driving assistance method and a driving assistance unit for a vehicle. Background Art

[0002] When a vehicle is driving on special road conditions such as snow and rocks, its traffic capacity will be limited. This phenomenon is particularly prominent in electric vehicles, because the motor of an electric vehicle can generate a large driving torque at low speeds, which can easily cause the wheels to lose grip and slip. Faced with such challenges, one solution is to rely on the driver's driving skills to steer the vehicle through special terrain, which undoubtedly places high demands on the driver's vehicle control level and reduces the vehicle's ease of use. Another solution is that for vehicles equipped with multiple control modes for different road conditions, the driver manually switches to a control mode suitable for the current road conditions. However, this not only increases the driver's operating burden, but may also cause control delays due to the time required for the mode switching process. Summary of the invention

[0003] In this context, the present invention aims to provide a vehicle driving assistance solution, which provides an adaptive control scheme by detecting the wheel stability condition and the tension or compression condition of the wheel suspension, so as to automatically execute a control strategy adapted to the current road condition.

[0004] According to an embodiment of one aspect of the present invention, a driving assistance unit for a vehicle is provided, comprising: a first detection module, configured to detect whether each wheel is a stable wheel or an unstable wheel based on the slip rate of each wheel, so as to obtain a first detection result; a second detection module, configured to detect whether each wheel suspension is in a compressed state or a stretched state based on the suspension travel of each wheel, and to detect the acceleration difference between the actual acceleration and the calculated acceleration of the vehicle, so as to obtain a second detection result; and a decision module, configured to determine a driving assistance strategy according to the first detection result and the second detection result; wherein, if the first detection result is that all four wheels are unstable In the case where the first detection result is that there is at least one stable wheel and the second detection result is that at least one wheel suspension is in a compressed state or a stretched state; or, when the first detection result is that all four wheels are unstable wheels and the second detection result is that the acceleration difference is greater than the first threshold value of the acceleration difference, the driving assistance strategy is the first driving assistance strategy; and in the case where the first detection result is that there is at least one stable wheel and the second detection result is that at least one wheel suspension is in a stretched state or a compressed state; or, when the first detection result is that there is at least one stable wheel and the second detection result is that the acceleration difference is greater than the first threshold value of the acceleration difference, the driving assistance strategy is the second driving assistance strategy.

[0005] According to an embodiment of another aspect of the present invention, a vehicle is provided, including a driving assistance unit according to an embodiment of the present invention.

[0006] According to an embodiment of yet another aspect of the present invention, a driving assistance method for a vehicle is provided, comprising: detecting whether each wheel is a stable wheel or an unstable wheel based on the wheel speed or slip rate of each wheel to obtain a first detection result; detecting whether each wheel suspension is in a compressed state or a stretched state based on the suspension stroke of each wheel, and detecting the acceleration difference between the actual acceleration of the vehicle and the calculated acceleration to obtain a second detection result; determining a driving assistance strategy according to the first detection result and the second detection result; wherein, when the first detection result is that all four wheels are unstable wheels and the second detection result is that at least one wheel suspension is in a compressed state or a stretched state; or, when the first detection result is that all four wheels are unstable wheels and the second detection result is that the acceleration difference is greater than a first threshold value of the acceleration difference, the driving assistance strategy is a first driving assistance strategy; and when the first detection result is that there is at least one stable wheel and the second detection result is that at least one wheel suspension is in a stretched state or a compressed state; or, when the first detection result is that there is at least one stable wheel and the second detection result is that the acceleration difference is greater than a first threshold value of the acceleration difference, the driving assistance strategy is a second driving assistance strategy.

[0007] According to an embodiment of still another aspect of the present invention, a computer program product is provided, which includes computer executable instructions, and when the instructions are executed, one or more processors are caused to perform a driving assistance method according to an embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The technical solution of the present invention will become clearer from the following detailed description in conjunction with the accompanying drawings. It is understood that these drawings are only used for exemplary description and are not intended to limit the scope of protection of the present invention.

[0009] Figure 1 is a schematic block diagram of a driving assistance system according to an embodiment of the present invention, which includes a driving assistance unit according to an embodiment of the present invention.

[0010] Figure 2 Flow chart of a driving assistance method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0011] The specific implementation of the present invention is described below in conjunction with the accompanying drawings.

[0012] Figure 1A driving assistance system 100 (hereinafter referred to as “system 100 ” in some places) according to an embodiment of the present invention is shown, which includes a sensor unit 10 , a driving assistance unit 20 , and an execution unit 30 .

[0013] The sensor unit 10 is used to provide information related to the vehicle driving state, such as vehicle speed (e.g., vehicle speed in the driving direction), wheel speed and acceleration of each wheel, slip rate of each wheel, suspension travel of each wheel, steering wheel angle, etc.

[0014] The information related to the vehicle driving state can be directly obtained based on the measurement results of the sensor, or can be obtained by calculating the measurement values ​​of the sensor. For example, the steering wheel angle can be directly obtained based on the measurement of the steering wheel angle sensor. The slip rate of the wheel can be obtained by calculating the ratio of the difference between the vehicle speed measured by the sensor and the wheel speed to the vehicle speed.

[0015] In one embodiment, the sensor unit 10 may include sensors for sensing parameters such as vehicle speed, wheel speed, steering wheel angle, and may also include sensors for receiving information data from outside the vehicle, for example, receiving information related to the vehicle's driving status from an edge cloud or a cloud server via V2X communication.

[0016] The driving assistance unit 20 is connected to the sensor unit 10 for communication to obtain information related to the vehicle driving state. The driving assistance unit 20 detects the stability state of each wheel and the compression or extension state of each wheel suspension according to the acquired information, and decides on an adaptive driving assistance strategy according to the detection results. In addition, the driving assistance unit 20 can also determine the road surface type of the vehicle driving on according to the detection results, and make a driving assistance strategy adapted to the road surface type according to the road surface type, so as to respond quickly and accurately to the current road conditions.

[0017] In the embodiment of the present invention, a “stable wheel” refers to a wheel that keeps rotating normally without slipping; an “unstable wheel” refers to a wheel that slips during rotation.

[0018] In an embodiment of the present invention, "the wheel suspension is in a compressed state" means that the wheel suspension stroke is shortened and maintained in the shortened state for a predetermined time period compared to when the vehicle is stationary on a horizontal road surface, that is, the wheel suspension is compressed for more than a predetermined time period. "The wheel suspension is in a stretched state" means that the wheel suspension stroke is increased and maintained in the increased state for a predetermined time period compared to when the vehicle is stationary on a horizontal road surface, that is, the suspension is stretched for more than a predetermined time period. Here, the predetermined time period is predetermined, for example, determined to be greater than the time period during which the wheel suspension stroke changes when the vehicle experiences a short fluctuation when driving over an uneven road surface such as a pothole. In this way, the wheel suspension stroke change according to an embodiment of the present invention can be distinguished from the short fluctuations experienced under bumpy road conditions.

[0019] In one embodiment, the driving assistance unit 20 includes a first detection module 21, a second detection module 22, an identification module 23, and a decision module 24. It is understood that the naming of these modules is functional and is not intended to limit their implementation methods or physical locations. For example, these modules can be implemented on the same chip or circuit, or on different chips or circuits. In addition, some or all of these modules can be combined into one module, or further divided into multiple sub-modules.

[0020] The driving assistance unit 20 and its various modules can be implemented in hardware or software or a combination of software and hardware. For the part implemented in hardware, it can be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, electronic units designed to perform their functions, or a combination thereof. For the part implemented in software, it can be implemented with the help of microcodes, program codes or code segments, and they can also be stored in machine-readable storage media such as storage components.

[0021] In one embodiment, the driving assistance unit 20 may be provided in an electronic control unit (ECU) of the vehicle, or in a vehicle body controller (VCU) of the vehicle, or in a domain controller of the vehicle.

[0022] In one embodiment, some of the multiple modules of the driving assistance unit 20 are arranged in one ECU of the vehicle, and another part of the modules are arranged in another ECU of the vehicle or in the VCU.

[0023] In one embodiment, the driving assistance unit 20 is implemented as including a memory and a processor. The memory contains instructions, which, when executed by the processor, enable the processor to perform the driving assistance method according to the embodiment of the present invention.

[0024] The execution unit 30 is connected in communication with the driving assistance unit 20, and is used to execute the driving assistance strategy decided by the driving assistance unit 20. The execution unit 30, for example, includes a brake actuator of the vehicle, which is used to execute the braking control decided by the driving assistance unit 20. The execution unit 30, for example, also includes a drive actuator of the vehicle, which is used to execute the drive control decided by the driving assistance unit 20. The execution unit 30, for example, also includes an ECU or a VCU electrically connected to the driving assistance unit 20, which is used to execute the control scheme decided by the driving assistance unit 20, for example, adjusting the response characteristics of the driving torque.

[0025] Figure 2 2 is a flow chart of a vehicle driving assistance method 200 according to an embodiment of the present invention. The method 200 may be executed by the system 100 or the driving assistance unit 20. The following takes the driving assistance unit 20 executing the method 200 as an example to introduce a specific implementation of the method 200.

[0026] See also Figure 2 In box 202, the first detection module 21 detects whether each wheel is a stable wheel or an unstable wheel based on the slip rate of each wheel to obtain a first detection result.

[0027] In one embodiment, the first detection module 21 obtains the slip rate of each wheel from the sensor unit 10, and compares the slip rate of each wheel with the slip rate threshold value. If the slip rate of a wheel is greater than the slip rate threshold value, the wheel is determined to be an unstable wheel, that is, the wheel is detected to be an unstable wheel. If the slip rate of a wheel is less than or equal to the slip rate threshold value, the wheel is determined to be a stable wheel, that is, the wheel is detected to be a stable wheel. In this way, a first detection result including each wheel being a stable wheel or an unstable wheel is obtained. According to an embodiment of the present invention, the slip rate threshold value is predetermined and can be adjusted according to the real-time vehicle speed and the lateral and longitudinal adhesion characteristics of the wheel. The present invention does not limit the specific values ​​of the slip rate threshold value and its adjustment amount.

[0028] In block 204, the second detection module 22 detects whether the suspension of each wheel is in a compressed state or a stretched state based on the suspension travel of each wheel, and detects the acceleration difference between the actual acceleration of the vehicle and the calculated acceleration, so as to obtain a second detection result. In general, the second detection module 22 performs two aspects of detection: one aspect of the detection is the change of the wheel suspension travel; the other aspect of the detection is the acceleration obstruction condition of the vehicle. The following introduces the specific embodiments of the detection of these two aspects.

[0029] In one embodiment, the second detection module 22 obtains the suspension stroke of each wheel from the sensor unit 10, and compares the suspension stroke of each wheel with the reference suspension stroke. The reference suspension stroke refers to the wheel suspension stroke when the vehicle is parked on a horizontal road. If the suspension stroke of a wheel is less than the reference suspension stroke, it is determined that the wheel suspension is in a compressed state. If the suspension stroke of a wheel is greater than the reference suspension stroke, it is determined that the wheel suspension is in a stretched state. In this way, a detection result including whether the suspension of each wheel is in a compressed state or a stretched state is obtained.

[0030] In one embodiment, the second detection module 22 compares the acceleration difference between the actual acceleration and the calculated acceleration of the vehicle with the first threshold of the acceleration difference to obtain a detection result including whether the acceleration difference is greater than the first threshold of the acceleration difference. The actual acceleration of the vehicle can be obtained by the sensor unit 10. The calculated acceleration of the vehicle is a theoretical acceleration of the vehicle calculated based on the driving force and the mass of the vehicle, for example, the acceleration that the vehicle should have calculated using a model. When the actual acceleration of the vehicle is less than the calculated acceleration and the difference between them is greater than the acceleration threshold, it means that the vehicle is at risk of being hindered from accelerating.

[0031] In box 206 , the decision module 23 determines a driving assistance strategy according to the first detection result and the second detection result.

[0032] Specifically, when the first detection result is that all four wheels are unstable wheels (i.e., all four wheels are in a slipping state), and the second detection result is that at least one wheel suspension is in a compressed or stretched state (i.e., the suspension stroke of one, two, three or four wheel suspensions has changed, shortened or increased relative to the reference wheel suspension stroke); or, when the first detection result is that all four wheels are unstable wheels and the second detection result is that the acceleration difference between the actual acceleration of the vehicle and the calculated acceleration is greater than the first threshold value of the acceleration difference, the decision module 23 determines to execute the first driving assistance strategy.

[0033] When the first detection result is that there is at least one stable wheel among the four wheels (i.e., the number of stable wheels can be one, two, three or four), and the second detection result is that at least one wheel suspension is in a tension or compression state (i.e., at least one wheel suspension stroke has changed, shortened or increased relative to a reference suspension stroke); or, when the first detection result is that there is at least one stable wheel among the four wheels and the second detection result is that the acceleration difference between the actual acceleration of the vehicle and the calculated acceleration is greater than a first threshold value of the acceleration difference, the decision module 23 determines to execute the second driving assistance strategy.

[0034] The first driving assistance strategy is described in detail below. The first driving assistance strategy includes one or more of the following. In other words, according to the first driving assistance strategy, any one or more of the following strategies can be executed, and when multiple strategies are executed, their execution order is not limited.

[0035] (1) Reduce the ratio of the vehicle's driving torque or driving force to the accelerator opening; reduce the torque loading slope; and apply braking to the unstable wheel to limit the slip of the unstable wheel.

[0036] "Reducing the ratio of the vehicle's driving torque or driving force to the throttle opening" means: modifying the ratio between the throttle opening and the vehicle's driving torque or driving force (i.e., the established corresponding relationship or established mapping relationship) so that the driving torque or driving force corresponding to the same throttle opening is reduced. For example, the driving torque or driving force corresponding to each throttle opening is reduced by 10-20%, that is, at the same throttle opening, the driving torque or driving force will be adjusted to 80%-90% of the original level. Based on such manipulation, when the driver steps on the accelerator pedal or the driving assistance system gives a throttle command, the increase in the driving torque or driving force will be reduced relative to their established mapping relationship.

[0037] "Reducing the torque loading slope" means: slowing down the rate at which torque increases relative to time or angle of rotation. By reducing the torque loading slope, the increase in torque will be reduced at the same angle of rotation or the same time change, thereby slowing down the rate at which torque rises. Based on such manipulation, the vehicle's power output can be made smoother. This adjustment is particularly meaningful for electric vehicles because electric vehicle motors have the characteristic of instantaneous high torque output. By reducing the torque loading slope, this problem can be effectively solved, thereby ensuring that the vehicle can drive safely and stably while responding to the driver's accelerator pedal input or the acceleration request of the driving assistance system.

[0038] "Applying braking to the unstable wheel" includes applying braking force and / or reverse driving force to the unstable wheel, thereby suppressing the slip of the unstable wheel. In one embodiment, applying braking to the unstable wheel limits the slip amount of the unstable wheel to a first predetermined range.

[0039] (2) When the wheel speed or acceleration of any wheel is greater than a corresponding threshold value, braking is applied to the wheel so that the slip amount of the wheel is limited to a second predetermined range.

[0040] In one embodiment, when the wheel speed of any wheel is greater than the wheel speed threshold, a braking force and / or a reverse driving force is applied to the wheel so that the slippage of the wheel is limited to a second predetermined range. According to an embodiment of the present invention, the wheel speed threshold is predetermined and can be adjusted according to the real-time vehicle speed and the lateral and longitudinal adhesion characteristics of the wheel. The present invention does not limit the specific values ​​of the wheel speed threshold and its adjustment amount.

[0041] In another embodiment, when the acceleration of any wheel is greater than the wheel acceleration threshold, a braking force and / or a reverse driving force is applied to the wheel so that the slip of the wheel is limited to a second predetermined range. According to an embodiment of the present invention, the wheel acceleration threshold is predetermined and can be adjusted according to the actual wheel end drive signal size and wheel speed. The present invention does not limit the specific values ​​of the wheel acceleration threshold and its adjustment amount.

[0042] According to an embodiment of the present invention, the first and second predetermined ranges for limiting the slippage of the vehicle may be the same or different. Both ranges may be obtained based on actual vehicle test results and / or model calculations. Moreover, the two ranges may be adjusted based on the needs of the vehicle user so that the vehicle behavior meets the user's expectations.

[0043] (3) When the vehicle is traveling uphill, the driving force of the vehicle is limited to be equal to or slightly greater than the component of the vehicle's weight in the direction parallel to the slope. "Slightly greater than" can be 100% to 110% of the component of the vehicle's weight in the direction parallel to the slope, or the sum of the component of the vehicle's weight in the direction parallel to the slope and a smaller redundancy. Based on such control, the driving wheels can have sufficient power to climb the slope and avoid excessive slippage (for example, wheel spin) caused by excessive driving force.

[0044] (4) When the requested steering wheel angle is greater than the angle threshold, the driving torque or driving force on the steering wheel is reduced. The steering wheel angle request may be issued by the driver (e.g., driver driving mode) or by the driving assistance system (e.g., automatic driving mode). Based on such manipulation, the lateral force (lateral grip of the tire) can be increased by reducing the longitudinal force (forward thrust) on the driving wheel, thereby ensuring that the steering response of the vehicle can meet (match) the requested steering wheel angle.

[0045] (5) When the actual acceleration of the vehicle is less than the calculated acceleration and their difference is greater than the second threshold of the acceleration difference, and the vehicle speed is less than the vehicle speed threshold, the decision module 24 predicts that the vehicle has an acceleration obstruction phenomenon or is about to have an acceleration obstruction. Here, the definition and embodiment of the calculated acceleration are the same as those of the above-mentioned calculated acceleration, so the above-mentioned related descriptions also apply here. The second threshold of the acceleration difference is greater than the first threshold of the acceleration difference, which means that the deviation between the actual acceleration and the calculated acceleration here is greater than the above-mentioned situation where the first threshold of the acceleration difference is used. The occurrence of such a situation means that a large driving force is applied to the vehicle but the vehicle speed is still very low. According to an embodiment of the present invention, the second threshold of the acceleration difference and the vehicle speed threshold are both predetermined. Moreover, these two thresholds are jointly determined through actual vehicle testing and / or model calculations to jointly describe the conditions for predicting vehicle traffic obstruction.

[0046] When it is predicted that the vehicle is at risk of being blocked, a warning of the risk of being blocked can be issued to the driver through the human-machine interface (not shown) of the vehicle. The advantage of this is that the risk of being blocked can be predicted by analyzing the vehicle behavior and the driver can be reminded so that the driver can take countermeasures before the vehicle is blocked.

[0047] If it is predicted that the vehicle is at risk of being blocked, the following strategy can also be implemented: control the vehicle to brake and stop, and then reverse for a certain distance before driving through the current road section at a controlled speed. The controlled speed and reverse distance can be determined by the following method: record the first speed V1 of the vehicle when it was at this position in the previous cycle at the time when the vehicle stopped, and determine the second speed V2 of the vehicle after the vehicle completes the reverse and moves forward again to reach the position as equal to the sum of the first speed V1 and the predetermined speed offset V_Off. Then, the minimum distance required to ensure that the vehicle can reach the second speed V2 when it reaches the position is calculated based on the second speed V2 and the road friction coefficient as the reverse distance.

[0048] (6) When the acceleration difference between the actual acceleration of the vehicle and the calculated acceleration is greater than the first threshold value of the acceleration difference and the vehicle speed is greater than the vehicle speed threshold value (for example, in a high-speed driving state), the slip ratio threshold is adjusted in an increasing direction, for example, the slip ratio threshold is increased by a first slip ratio adjustment amount. According to an embodiment of the present invention, the first slip ratio adjustment amount may be predetermined and may be adjusted according to the real-time vehicle speed and the lateral and longitudinal adhesion characteristics of the wheel. The present invention does not limit the specific value of the first slip ratio adjustment amount. By such an adjustment, a larger amount of slippage of the wheel within a certain range may be allowed.

[0049] Next, the second driving assistance strategy is introduced. The second driving assistance strategy includes one or more of the following. In other words, according to the second driving assistance strategy, any one or more of the following strategies can be executed, and when multiple strategies are executed, their execution order is not limited.

[0050] (1) Increase the ratio of the vehicle's driving torque or driving force to the accelerator opening and apply braking to the unstable wheel.

[0051] "Increasing the ratio of the vehicle's driving torque or driving force to the throttle opening" means: modifying the ratio between the throttle opening and the vehicle's driving torque or driving force (i.e., the established corresponding relationship or established mapping relationship) so that the driving torque or driving force corresponding to the same throttle opening is increased. For example, the driving torque or driving force corresponding to each throttle opening is increased by 10-20%, that is, at the same throttle opening, the driving torque or driving force will be adjusted to the original level of 110%-120%. Based on such manipulation, when the driver steps on the accelerator pedal or the driving assistance system gives a throttle command, the increase in the driving torque or driving force will increase relative to their established mapping relationship.

[0052] "Applying braking to the unstable wheel" includes applying a braking force and / or a reverse driving force to the unstable wheel, thereby suppressing the slippage of the unstable wheel. In one embodiment, braking is applied to the unstable wheel so that the slippage of the unstable wheel is limited to a third predetermined range. According to an embodiment of the present invention, the third predetermined range here may be the same as or different from the above-mentioned first predetermined range. Similarly, the third predetermined range is obtained based on actual vehicle test results and / or model calculations, and may be adjusted based on the needs of vehicle users so that the vehicle behavior meets user expectations.

[0053] (2) When the difference between the actual driving torque and the target driving torque of the vehicle or the difference between the actual driving force and the target driving force is greater than the corresponding difference threshold, braking is applied to the unstable wheel according to a predetermined correspondence between the driving torque or the driving force and the braking force, for example, braking force and / or reverse driving force is applied to the unstable wheel.

[0054] (3) When the acceleration difference between the actual acceleration of the vehicle and the calculated acceleration is greater than the first threshold value of the acceleration difference, the slip ratio threshold is adjusted in an increasing direction, for example, the slip ratio threshold is increased by a second slip ratio adjustment amount. Similarly, the second slip ratio adjustment amount may be predetermined and may be adjusted according to the real-time vehicle speed and the lateral and longitudinal adhesion characteristics of the wheel. The present invention does not limit the specific value of the second slip ratio adjustment amount. By such an adjustment, a larger amount of slippage of the wheel within a certain range may be allowed. The second slip ratio adjustment amount may be equal to the first slip ratio adjustment amount, or the slip ratio adjustment amounts of the two may be unequal.

[0055] The difference between the actual driving torque of the vehicle and the target driving torque is greater than the torque difference threshold (for example, the actual driving torque is too large relative to the target driving torque) or the difference between the actual driving force and the target driving force is greater than the driving force difference threshold (for example, the actual driving force is too large relative to the target driving force), which means that the actual driving performance / behavior of the vehicle does not follow the set target well. In this case, in order to avoid tire damage due to excessive slipping of the driving wheels, feed-forward braking is used to solve this problem.

[0056] In one embodiment, a coordinate system is constructed to describe the predetermined relationship between the driving torque (or driving force) and the braking force, wherein the horizontal axis represents the magnitude of the driving force or driving torque, and the vertical axis represents the magnitude of the braking force. A curve is drawn on the coordinate system, and the curve represents the functional relationship (corresponding relationship) between the driving torque or driving force and the required braking force.

[0057] In addition, according to an embodiment of the present invention, after obtaining the first and second detection results, the method 200 may enter box 208. In box 208, the identification module 23 identifies the type of the road surface on which the vehicle is traveling as the first type or the second type according to the first and second detection results. Then, the method 200 enters box 210. In box 210, the decision module 24 determines whether to execute the first driving assistance strategy or the second driving assistance strategy according to the identified road surface type.

[0058] According to this embodiment, the road surface type is first identified based on a first detection result characterizing the response of the wheel stability condition to the road surface condition and a second detection result characterizing the response of the wheel suspension travel change and the vehicle acceleration obstruction condition to the road surface condition, and then a determination is made as to whether to implement the first or second driving assistance strategy based on the identified road surface type.

[0059] Specifically, when the first detection result is that all four wheels are unstable wheels, and the second detection result is that at least one wheel suspension is in a compressed or stretched state; or, when the first detection result is that all four wheels are unstable wheels and the second detection result is that the acceleration difference between the actual acceleration of the vehicle and the calculated acceleration is greater than the first threshold of the acceleration difference, the identification result is that the type of the road surface on which the vehicle is traveling is the first type. For the first type of road surface, the decision module determines to execute the first driving assistance strategy. The first type of road surface is a soft road surface that will produce vertical deflection under the action of the vehicle load and may reduce the vehicle's passability. The first type of road surface is, for example, a deep snow or muddy road surface.

[0060] When the first detection result is that there is at least one stable wheel among the four wheels, and the second detection result is that at least one wheel suspension is in a tension or compression state; or when the first detection result is that there is at least one stable wheel among the four wheels and the second detection result is that the acceleration difference between the actual acceleration of the vehicle and the calculated acceleration is greater than the first threshold of the acceleration difference, the identification result is that the type of the road surface on which the vehicle is traveling is the second type. For the second type of road surface, the decision module determines to execute the second driving assistance strategy. The second type of road surface is an uneven hard road surface that may reduce the vehicle's passability. The second type of road surface is, for example, a rocky road surface.

[0061] In the embodiment of the present invention, the vehicle refers to a four-wheel vehicle, that is, including left and right front wheels coupled to the front axle of the vehicle and left and right rear wheels coupled to the rear axle of the vehicle.

[0062] In an embodiment of the present invention, a variety of thresholds or predetermined values ​​are used, and these thresholds are all predetermined, for example, they can be predetermined based on actual vehicle test results and / or models. The present invention does not limit their specific values. Moreover, these thresholds can also be customized thresholds for vehicle users based on the preferences of vehicle users (e.g., OEM or vehicle drivers), so that the vehicle steering style meets the preferences of vehicle users. It should be understood that the customized thresholds that meet the preferences of vehicle users are determined to fully ensure the safety of vehicle driving. Therefore, these customized thresholds should be understood to meet the preferences of vehicle users to a certain extent, without following the preferences of vehicle users at the expense of vehicle safety.

[0063] According to an embodiment of the present invention, a vehicle is further provided, which includes the above-mentioned driving assistance unit. Therefore, the vehicle according to the embodiment of the present invention has the above-mentioned features and advantages.

[0064] According to an embodiment of the present invention, a machine-readable storage medium is further provided, which stores executable instructions. When the instructions are executed, one or more processors execute the driving assistance method 200 as described above.

[0065] According to an embodiment of the present invention, a computer program product is further provided, which includes computer executable instructions, and when the instructions are executed, one or more processors execute the driving assistance method 200 as described above.

[0066] It should be noted that all operations in the method described above are merely exemplary, and the present disclosure is not limited to any operation in the method or the order of these operations, but should cover all other equivalent transformations under the same or similar concept.

[0067] It should be noted that the processor may use any combination of one or more of the following: an appropriate central processing unit, CPU, multiprocessor, single-chip microcomputer, digital signal processor, DSP, application-specific integrated circuit, etc., capable of executing software instructions of a computer program stored in the memory. Therefore, the memory may be considered as part of or forming part of a computer program product. The processor may be configured to execute a computer program stored therein to cause the controller to perform the required steps.

[0068] It should be noted that software should be broadly considered to represent instructions, instruction sets, codes, code segments, program codes, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, running threads, processes, functions, etc. The software may reside in a computer-readable medium. The computer-readable medium may include, for example, a memory, which may be, for example, a magnetic storage device (e.g., a hard disk, a floppy disk, a magnetic stripe), an optical disk, a smart card, a flash memory device, a random access memory (RAM), a read-only memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), a register, or a removable disk. Although the memory is shown as being separate from the processor in the various aspects provided in the present disclosure, the memory may also be located inside the processor (e.g., a cache or a register).

[0069] The above description is provided to enable any person skilled in the art to implement the various aspects described herein. Various modifications to these aspects are apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. Therefore, the claims are not intended to be limited to the aspects shown herein. All structural and functional equivalents of elements of various aspects described in this disclosure that are known or to be known to those skilled in the art will be expressly included herein by reference and are intended to be covered by the claims.

Claims

1. A driving assistance unit for a vehicle, comprising: A first detection module is configured to detect whether each wheel is a stable wheel or an unstable wheel based on the slip rate of each wheel to obtain a first detection result; a second detection module configured to detect whether the suspension of each wheel is in a compression state or a tension state based on the suspension travel of each wheel, and to detect an acceleration difference between an actual acceleration of the vehicle and a calculated acceleration, so as to obtain a second detection result; as well as A decision module configured to determine a driving assistance strategy according to the first detection result and the second detection result; Wherein, when the first detection result is that all four wheels are unstable wheels and the second detection result is that at least one wheel suspension is in a compressed state or a stretched state; or when the first detection result is that all four wheels are unstable wheels and the second detection result is that the acceleration difference is greater than a first acceleration difference threshold, the driving assistance strategy is the first driving assistance strategy; and When the first detection result is that there is at least one stable wheel and the second detection result is that at least one wheel suspension is in a tension state or a compression state; or, when the first detection result is that there is at least one stable wheel and the second detection result is that the acceleration difference is greater than a first threshold value of the acceleration difference, the driving assistance strategy is the second driving assistance strategy.

2. The driving assistance unit according to claim 1, further comprising an identification module configured to identify whether the vehicle driving on the road surface is the first type of road surface or the second type of road surface based on the first and second detection results; wherein, When the first detection result is that all four wheels are unstable wheels and the second detection result is that at least one wheel suspension is in a compressed state or a stretched state; Alternatively, when the first detection result is that all four wheels are unstable wheels and the second detection result is that the acceleration difference is greater than the first acceleration difference threshold, the recognition result is that the vehicle driving road surface is the first type of road surface, and the decision module determines the first driving assistance strategy; When the first detection result is that there is at least one stable wheel and the second detection result is that at least one wheel suspension is in a tension state or a compression state; Alternatively, when the first detection result is that there is at least one stable wheel and the second detection result is that the acceleration difference is greater than the first acceleration difference threshold, the recognition result is that the vehicle is traveling on a second type of road surface, and the decision module determines the second driving assistance strategy.

3. The driving assistance unit according to claim 2, wherein: The first type of road surface is a soft road surface that will produce vertical deflection under the action of vehicle load and may reduce the vehicle's passability. Optionally, the first type of road surface is a snowy or muddy road surface; and The second type of road surface is an uneven hard road surface that may reduce the vehicle's passability. Optionally, the second type of road surface is a rocky road surface.

4. The driving assistance unit according to claim 1, wherein: The first detection module is configured as follows: When the slip rate of a wheel is greater than a slip rate threshold, determining the wheel as an unstable wheel; and When the slip rate of a wheel is less than or equal to the slip rate threshold, the wheel is determined as a stable wheel.

5. The driving assistance unit according to claim 1, wherein: The second detection module is configured as follows: When a wheel suspension stroke is less than a reference wheel suspension stroke and this state is maintained for a predetermined time period, determining that the wheel suspension is in a compressed state; and When a wheel suspension stroke is greater than the reference suspension stroke and maintains this state for a predetermined time, it is determined that the wheel suspension is in a stretched state. The reference suspension travel refers to the wheel suspension travel when the vehicle is parked on a horizontal road.

6. The driving assistance unit according to claim 1, wherein: The first driver assistance strategy includes: - Reduce the ratio of the vehicle's driving torque or driving force to the accelerator opening; - Reduce the torque loading slope; - Applying a braking force to the unstable wheel so that the slip amount of the unstable wheel is limited to a first predetermined range.

7. The driving assistance unit according to claim 1, wherein: The first driver assistance strategy includes: When the wheel speed or acceleration of any wheel is greater than a corresponding threshold value, braking is applied to the wheel so that the slip amount of the wheel is limited to a second predetermined range.

8. The driving assistance unit according to claim 1, wherein: The first driver assistance strategy includes: When the vehicle is traveling uphill, the driving force of the vehicle is determined to be equal to or slightly greater than the component of the vehicle's gravity in a direction parallel to the slope.

9. The driving assistance unit according to claim 1, wherein: The first driver assistance strategy includes: When the requested steering wheel angle is greater than the angle threshold, the driving torque or driving force on the steering wheel is reduced according to a predetermined ratio.

10. The driving assistance unit according to claim 1, wherein: The first driver assistance strategy includes: When the difference between the actual acceleration and the calculated acceleration of the vehicle is greater than the second acceleration difference threshold and the vehicle speed is less than the vehicle speed threshold, one or both of the following strategies are executed: - Predict the risk of a vehicle being blocked and send a message to the driver to alert him of the risk; -Control the vehicle to stop, back up a certain distance, and then drive through the current road section at a controlled speed. The second acceleration difference threshold is greater than the first acceleration difference threshold.

11. The driving assistance unit according to claim 1, wherein: The first driver assistance strategy includes: When the acceleration difference is greater than the first acceleration difference threshold and the vehicle speed is greater than the vehicle speed threshold, the wheel slip ratio threshold is increased.

12. The driving assistance unit according to claim 1, wherein: The second driving assistance strategy includes: The ratio of the driving torque or driving force of the vehicle to the accelerator opening is increased, and braking is applied to the unstable wheel so that the slip amount of the unstable wheel is limited to a first predetermined range.

13. The driving assistance unit according to claim 1, wherein: The second driving assistance strategy includes: When the difference between the vehicle's actual driving torque and the target driving torque is greater than the torque difference threshold or the difference between the actual driving force and the target driving force is greater than the driving force difference threshold, braking is applied to the unstable wheel according to a predetermined correspondence between the driving torque or driving force and the braking force.

14. The driving assistance unit according to claim 1, wherein: The second driving assistance strategy includes: When the acceleration difference is greater than a first acceleration difference threshold, the wheel slip ratio threshold is increased.

15. A vehicle comprising the driving assistance unit according to any one of claims 1 to 14.

16. A driving assistance method for a vehicle, comprising: Detecting whether each wheel is a stable wheel or an unstable wheel based on the wheel speed or slip rate of each wheel to obtain a first detection result; Detecting whether the suspension of each wheel is in a compression state or a tension state based on the suspension travel of each wheel, and detecting the acceleration difference between the actual acceleration and the calculated acceleration of the vehicle to obtain a second detection result; determining a driving assistance strategy according to the first detection result and the second detection result; Wherein, when the first detection result is that all four wheels are unstable wheels and the second detection result is that at least one wheel suspension is in a compressed state or a stretched state; or when the first detection result is that all four wheels are unstable wheels and the second detection result is that the acceleration difference is greater than a first acceleration difference threshold, the driving assistance strategy is the first driving assistance strategy; and When the first detection result is that there is at least one stable wheel and the second detection result is that at least one wheel suspension is in a tension state or a compression state; or, when the first detection result is that there is at least one stable wheel and the second detection result is that the acceleration difference is greater than a first threshold value of the acceleration difference, the driving assistance strategy is the second driving assistance strategy. 17 . A computer program product comprising computer executable instructions, which when executed cause one or more processors to perform the driving assistance method according to claim 15 .

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