Vehicle active anti-skid method and system, electronic equipment and computer readable medium

Abstract

The invention provides an active anti-skid method for a vehicle, and belongs to the field of automobiles. Acquiring a target wheel speed difference during normal steering; according to the front and rear axle left and right wheel speed difference and the target wheel speed difference, a torque reduction coefficient is obtained; determining an activation state of an anti-slip function based on the vehicle speed, the required torque and the wheel speed signal; according to the torque reduction coefficient and the activation state, the final front and rear axle target torque is obtained, automatic skid resistance can be achieved when a large accelerator is started on the wet and slippery road surface, the coaxial wheel speed can be consistent without a differential lock, single-wheel skid is avoided, and the effect of a differential mechanism during steering is not affected.

Description

Technical Field

[0001] This invention relates to the field of automotive technology, and in particular to a vehicle active anti-skid method, system, electronic device, and computer-readable medium. Background Technology

[0002] When a vehicle starts with heavy acceleration on a wet or slippery surface or encounters a road with two parallel sections, it is prone to slipping, resulting in loss of power or even instability. Vehicles equipped with differential locks can solve this problem using the differential lock, but not all vehicles are equipped with differential locks. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art, and proposes a vehicle active anti-skid method and system.

[0004] In a first aspect, embodiments of the present invention provide a method for active anti-skid operation of a vehicle, comprising:

[0005] Obtain the speed difference between the left and right wheels of the front and rear axles;

[0006] Obtain the target wheel speed difference during normal steering;

[0007] The torque reduction coefficient is obtained based on the speed difference between the left and right wheels of the front and rear axles and the target wheel speed difference;

[0008] The activation status of the anti-skid function is determined based on vehicle speed, required torque, and wheel speed signals.

[0009] Based on the torque reduction coefficient and activation state, the final target torque for the front and rear axles is obtained.

[0010] In some embodiments, the step of obtaining the speed difference between the left and right wheels of the front and rear axles includes:

[0011] For the front axle, calculate the difference between the left wheel speed v_left_front and the right wheel speed v_right_front, and take the absolute value: Δv_front = |v_left_front - v_right_front|

[0012] For the rear axle, calculate the difference between the left wheel speed v_left_rear and the right wheel speed v_right_rear, and take the absolute value: Δv_rear = |v_left_rear - v_right_rear|

[0013] A first-order low-pass filter is used to smooth the wheel speed difference.

[0014] In some embodiments, the step of obtaining the target wheel speed difference during normal steering includes:

[0015] With the steering wheel angle δ and vehicle speed v as inputs, query the target yaw rate ω_t through a pre-calibrated interpolation table;

[0016] This interpolation table is calibrated through a sine sweep test: under various combinations of vehicle speeds and steering wheel angles, measure the actual yaw rate of the vehicle and establish a two-dimensional mapping table of ω_t = f(δ, v);

[0017] According to the target yaw rate ω_t and wheelbase L, calculate the target wheel speed difference Δv_wt between the inner and outer wheels: Δv_wt = ω_t * L.

[0018] In some of these embodiments, in the step of obtaining the torque reduction coefficient based on the left and right wheel speed differences of the front and rear axles and the target wheel speed difference, it includes:

[0019] For the front axle, use the filtered wheel speed difference Δv_front_filtered and the target wheel speed difference Δv_wt to look up the virtual differential lock torque reduction coefficient K_front of the front axle in a table;

[0020] For the rear axle, use Δv_rear_filtered and Δv_wt to look up K_rear in a table;

[0021] Perform gradient limitation on the torque reduction coefficient, that is, limit the change amount of the torque reduction coefficient in each calculation cycle.

[0022] In some of these embodiments, in the step of determining the activation state of the anti-skid function based on the vehicle speed, required torque, and wheel speed signal, it includes:

[0023] Obtain the vehicle state signals: vehicle speed v, target required torque T_req, and the validity signals of each wheel speed;

[0024] Check the global anti-skid function activation permission flag;

[0025] For a certain axle, the anti-skid function of that axle is only allowed to be activated when the wheel speed signals of both wheels of that axle are valid.

[0026] In some of these embodiments, it further includes the following steps: vehicle speed and required torque hysteresis processing, including:

[0027] Vehicle speed hysteresis: Set the vehicle speed upper limit v_high and lower limit v_low; if v > v_high, the vehicle speed enable flag is set to True; if v < v_low, it is set to False; if v_low ≤ v ≤ v_high, maintain the previous state;

[0028] Demand torque hysteresis: Set the torque upper limit T_high and the lower limit T_low; if T_req > T_high, set the torque enable flag to True; if T_req < T_low, set it to False; if T_low ≤ T_req ≤ T_high, maintain the previous state;

[0029] For each axle, the anti-skid function of the axle is activated only when the global activation is allowed, the wheel speed of the axle is valid, the vehicle speed enable flag is True, and the torque enable flag is True.

[0030] In some of these embodiments, in the step of obtaining the final front and rear axle target torques according to the torque reduction coefficient and the activation state, it includes:

[0031] For each axle, if the anti-skid enable is activated, use the torque reduction coefficient of the axle, otherwise the torque reduction coefficient is 1;

[0032] For four-wheel drive vehicles: Front axle target torque = min(front axle demand torque * front axle torque reduction coefficient, front axle maximum capable torque); Rear axle target torque = min(rear axle demand torque * rear axle torque reduction coefficient, rear axle maximum capable torque)

[0033] For two-wheel drive vehicles: Compare the front and rear axle torque reduction coefficients, take the minimum value as the total torque reduction coefficient, and the total target torque = total demand torque * total torque reduction coefficient;

[0034] Perform gradient limiting processing on the torque change to ensure smooth torque change.

[0035] In a second aspect, the present invention also provides a vehicle active anti-skid system, including:

[0036] A first wheel speed difference unit for obtaining the left and right wheel speed differences of the front and rear axles;

[0037] A second wheel speed difference unit for obtaining the target wheel speed difference during normal steering;

[0038] A torque reduction coefficient unit for obtaining the torque reduction coefficient according to the left and right wheel speed differences of the front and rear axles and the target wheel speed difference;

[0039] A judgment unit for determining the activation state of the anti-skid function based on the vehicle speed, demand torque, and wheel speed signal;

[0040] An output unit for obtaining the final front and rear axle target torques according to the torque reduction coefficient and the activation state.

[0041] In a third aspect, the present invention also provides an electronic device, including:

[0042] One or more processors;

[0043] Memory, used to store one or more programs;

[0044] When the one or more programs are executed by the one or more processors, the one or more processors implement any of the methods.

[0045] Fourthly, the present invention also provides a computer-readable medium on which a computer program is stored, wherein the computer program, when executed by a processor, implements the steps in any of the methods described.

[0046] The present invention provides a vehicle active anti-skid method that obtains the speed difference between the left and right wheels of the front and rear axles; obtains the target wheel speed difference during normal steering; obtains a torque reduction coefficient based on the speed difference between the left and right wheels of the front and rear axles and the target wheel speed difference; determines the activation state of the anti-skid function based on vehicle speed, required torque, and wheel speed signals; and obtains the final target torque of the front and rear axles based on the torque reduction coefficient and the activation state. This method can automatically prevent slippage when starting with high throttle on wet and slippery roads, and can achieve consistent wheel speeds on the same axle without the need for a differential lock, avoiding single-wheel slippage, and does not affect the function of the differential during steering. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the steps of an embodiment of the vehicle active anti-skid method of the present invention;

[0048] Figure 2 This is a schematic diagram of a structure of an embodiment of the vehicle active anti-skid system of the present invention;

[0049] Figure 3 This is a schematic diagram of the structure of an embodiment of the electronic device of the present invention. Detailed Implementation

[0050] To enable those skilled in the art to better understand the technical solutions of the present invention, exemplary embodiments of the present invention are described below in conjunction with the accompanying drawings, including various details of the embodiments of the present invention to aid understanding. These should be considered merely exemplary. Therefore, those skilled in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present invention. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0051] Where there is no conflict, the various embodiments of the present invention and the features thereof may be combined with each other.

[0052] As used herein, the term “and / or” includes any and all combinations of one or more related enumerated entries.

[0053] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, the singular forms “a” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that when the terms “comprising” and / or “made of” are used in this specification, the presence of the stated feature, integral, step, operation, element, and / or component is specified, but the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof is not excluded. Terms such as “connected” or “linked” are not limited to physical or mechanical connections but can include electrical connections, whether direct or indirect.

[0054] Unless otherwise specified, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art. It will also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having the meaning consistent with their meaning in the context of the relevant art and the invention, and will not be interpreted as having an idealized or overly formal meaning unless expressly so defined herein.

[0055] In the technical solution of this invention, the collection, storage, use, processing, transmission, provision, and disclosure of user personal information all comply with relevant laws and regulations and do not violate public order and good morals. The use of user data in this technical solution follows relevant national laws and regulations (e.g., the "Information Security Technology - Personal Information Security Specification"). For example: appropriate measures are taken for personal information access control; restrictions are imposed on the display of personal information; the purpose of using personal information does not exceed the scope of direct or reasonable association; and explicit identity targeting is eliminated when using personal information to avoid precisely locating a specific individual.

[0056] In related technologies, vehicles are prone to slipping when starting with high throttle on wet or slippery surfaces or when encountering opposing road surfaces, resulting in power loss or even instability. Vehicles equipped with differential locks can solve this problem using the differential lock, but not all vehicles are equipped with differential locks.

[0057] To address at least one of the technical problems existing in the aforementioned related technologies, the present invention provides a method for active anti-skid of vehicles. Figure 1 A flowchart illustrating the steps of an active anti-skid method for vehicles provided in an embodiment of the present invention.

[0058] like Figure 1 As shown, the active anti-skid method for this vehicle includes the following steps:

[0059] Step S10: Obtain the speed difference between the left and right wheels of the front and rear axles.

[0060] In this embodiment, the difference in wheel speed between the front and rear axles is obtained, and filtering is used to reduce the impact of slippage-induced fluctuations. Specifically, the implementation includes the following methods:

[0061] Wheel speed difference calculation: For the front axle, calculate the difference between the left wheel speed (v_left_front) and the right wheel speed (v_right_front), and take the absolute value: Δv_front = |v_left_front - v_right_front|; for the rear axle, calculate the difference between the left wheel speed (v_left_rear) and the right wheel speed (v_right_rear), and take the absolute value: Δv_rear = |v_left_rear - v_right_rear|. Wheel speed signals usually come from wheel speed sensors, and the accuracy and real-time performance of the signals must be ensured.

[0062] Furthermore, a first-order low-pass filter is used to smooth the wheel speed difference. The filter's transfer function is: Δv_filtered(k) = α * Δv(k) + (1-α) * Δv_filtered(k-1), where Δv(k) is the current wheel speed difference, Δv_filtered(k) is the filtered wheel speed difference, and α is the filter coefficient (given by calibration, typically ranging from 0 to 1). The initial value Δv_filtered(0) is set to the actual wheel speed difference Δv(0). The selection of the filter coefficient α depends on the vehicle's dynamic characteristics and is generally determined experimentally to balance response speed and smoothness.

[0063] Understandably, this step provides the foundational data for subsequent torque reduction coefficient calculations. Filtering ensures the stability of wheel speed differences, preventing control jitter caused by instantaneous fluctuations.

[0064] Step S20: Obtain the target wheel speed difference during normal steering.

[0065] In this embodiment, the difference in wheel speed between the inner and outer wheels during normal steering is estimated to distinguish between normal steering and slippage. The specific implementation is as follows:

[0066] Target yaw rate lookup table: Using steering wheel angle δ (unit: degrees or radians) and vehicle speed v (unit: km / h or m / s) as input, the target yaw rate ω_t (unit: rad / s) is looked up through a pre-calibrated interpolation table. This interpolation table is calibrated through a sinusoidal sweep frequency test: under various combinations of vehicle speed and steering wheel angle, the actual yaw rate of the vehicle is measured, and a two-dimensional mapping table of ω_t=f(δ,v) is established. Linear interpolation or spline interpolation is used to improve accuracy during lookup. The specific table is as follows:

[0067]

[0068] Target wheel speed difference calculation: Based on the target yaw rate ω_t and wheelbase L (unit: m, vehicle fixed parameter), calculate the inner and outer target wheel speed difference Δv_wt: Δv_wt = ω_t * L. This formula is based on vehicle steering geometry and represents the difference in linear velocity between the inner and outer wheels to meet steering requirements.

[0069] Understandably, this step provides a reference wheel speed difference during normal steering, which is compared with the actual filtered wheel speed difference in step S10 to identify slippage. If the actual wheel speed difference is much greater than the target wheel speed difference, it indicates that slippage may be occurring.

[0070] Step S30: Obtain the torque reduction coefficient based on the speed difference between the left and right wheels of the front and rear axles and the target wheel speed difference.

[0071] In this embodiment, the torque reduction coefficient is calculated based on the deviation between the actual wheel speed difference and the target wheel speed difference, and its rate of change is limited to avoid torque fluctuations. Specific implementation method:

[0072] Torque reduction coefficient lookup table: For the front axle, use the filtered wheel speed difference Δv_front_filtered and the target wheel speed difference Δv_wt to look up the table to obtain the front axle virtual differential lock torque reduction coefficient K_front. The table lookup input can be the wheel speed difference ratio (Δv_front_filtered / Δv_wt) or the difference (Δv_front_filtered-Δv_wt), the specific form of which is determined by calibration.

[0073] For the rear axle, the torque reduction coefficient K_rear is similarly obtained by looking up the table using Δv_rear_filtered and Δv_wt. The specific table is as follows:

[0074]

[0075] The table content is calibrated through bench or real vehicle testing. It is usually designed so that when the actual wheel speed difference is close to the target wheel speed difference, the torque reduction coefficient is close to 1 (no torque reduction); when the actual wheel speed difference is large, the torque reduction coefficient decreases (torque reduction).

[0076]

[0077] Gradient constraint processing: Gradient constraint is applied to the torque reduction coefficient K to ensure its smooth change. In each control cycle (e.g., 10ms), the change in torque reduction coefficient ΔK is calculated: ΔK = K_current - K_previous

[0078] If ΔK is greater than the upper bound gradient ΔK_max (calibrated value), then K_current = K_previous + ΔK_max; if ΔK is less than the lower bound gradient ΔK_min (calibrated value, usually negative), then K_current = K_previous + ΔK_min.

[0079] The gradient limit values ​​ΔK_max and ΔK_min are calibrated according to the characteristics of the vehicle's powertrain to avoid sudden torque changes.

[0080] As can be understood, the core of this step is to generate the torque reduction coefficient, with the outputs of steps S10 and S20 serving as inputs. Gradient limiting ensures the smoothness of torque changes, improving driving comfort.

[0081] Step S40: Determine the activation status of the anti-skid function based on vehicle speed, required torque, and wheel speed signals.

[0082] In this embodiment, the activation of the anti-slip function is determined based on the vehicle status signal, and hysteresis is incorporated to prevent frequent switching. Specific implementation method:

[0083] Acquire vehicle status signals: vehicle speed v, target torque T_req (from driver's throttle or controller), and validity signals of each wheel speed (Boolean value, indicating whether the wheel speed sensor is working properly).

[0084] Check the global anti-skid function activation indicator (which may come from the vehicle control system or driver switch).

[0085] For a given axle (front or rear), the anti-slip function is only allowed to be activated when both wheel speed signals for that axle are valid.

[0086] This embodiment obtains the vehicle speed, target torque requirement, and wheel speed validity signals. The anti-slip function is only allowed to be activated when the anti-slip function is enabled and the two wheel speed signals of a certain axle are valid. In addition, it is necessary to determine whether the vehicle speed and total torque requirement simultaneously meet the function activation conditions.

[0087] Furthermore, to avoid repeated enabling and disabling of the function due to minor fluctuations in vehicle speed and required torque, hysteresis processing is added. When the vehicle speed exceeds a certain upper limit, enabling is allowed; when the vehicle speed falls below a certain lower limit, enabling is disabled; if the vehicle speed is between the upper and lower limits, enabling remains at the previous state. Similarly, hysteresis processing is added for required torque. The anti-slip function is only activated when both vehicle speed and required torque allow it to be enabled. Specifically, this includes:

[0088] Vehicle speed hysteresis: Set the upper speed limit v_high and the lower speed limit v_low (calibration values). If v > v_high, the vehicle speed enable flag is set to True; if v < v_low, it is set to False; if v_low ≤ v ≤ v_high, the previous state is maintained.

[0089] Demand torque hysteresis: Set the upper torque limit T_high and the lower torque limit T_low (calibration values). If T_req > T_high, the torque enable flag is set to True; if T_req < T_low, it is set to False; if T_low ≤ T_req ≤ T_high, the previous state is maintained.

[0090] For each axle, the anti-skid function of that axle is activated only when global activation is allowed, the wheel speed of that axle is valid, the vehicle speed enable flag is True, and the torque enable flag is True.

[0091] When step S40 determines that the anti-skid function is activated (enabled): This "switch" closes, allowing the torque reduction coefficient to pass through. Next, K_used = K (the coefficient calculated in step S30, which may be less than 1) will be received. Finally, the target torque = demand torque × K, achieving the effect of torque reduction and anti-skid.

[0092] When step S40 determines that the anti-skid function is not activated (not enabled): This "switch" opens and outputs a default value. Next, K_used = 1 will be received. Finally, the target torque = demand torque × 1 = demand torque, and the vehicle outputs full torque without the anti-skid function intervening.

[0093] It can be understood that this step is a safety logic to ensure that the anti-skid function is activated only under appropriate conditions (such as medium to high vehicle speeds and torque demands), avoiding unnecessary intervention at low speeds or low torques. The hysteresis processing enhances system stability.

[0094] Step S50: Obtain the final target torques for the front and rear axles according to the torque reduction coefficient and the activation state.

[0095] In this embodiment, according to the torque reduction coefficient and the enable state, calculate the final target torque sent to the drive wheels, considering the drive type and the torque change gradient. The specific implementation method is as follows:

[0096] For each axle, if the anti-skid enable is activated, use the torque reduction coefficient (K_front or K_rear) calculated in step S30; otherwise, the torque reduction coefficient is set to 1.

[0097] Torque calculation for four-wheel drive vehicles: Front axle target torque T_front_target = min(T_front_req*K_front, T_front_max), where T_front_req is the required torque for the front axle (from the power distribution system), and T_front_max is the maximum torque capacity of the front axle (limited by the engine or electric motor). Rear axle target torque T_rear_target = min(T_rear_req*K_rear, T_rear_max), where T_rear_req is the required torque for the rear axle, and T_rear_max is the maximum torque capacity of the rear axle.

[0098] Understandably, for four-wheel drive vehicles, the required torque for the front axle is multiplied by the front axle torque reduction coefficient to obtain the target torque for the front axle. This target torque is then compared with the maximum capacity of the front axle, and the smaller value is taken as the front axle torque value. For the rear axle, the required torque for the rear axle is multiplied by the rear axle torque reduction coefficient to obtain the target torque for the rear axle. This target torque is then compared with the maximum capacity of the rear axle, and the smaller value is taken as the rear axle torque value.

[0099] Torque calculation for two-wheel drive vehicles: compare the torque reduction coefficients of the front and rear axles: K_total=min(K_front,K_rear), total target torque T_total_target=T_total_req*K_total, where T_total_req is the total required torque (directly from the driver's input).

[0100] It is understandable that for two-wheel drive vehicles, the torque reduction coefficients of the front and rear axles are compared and the smaller one is taken as the total torque reduction coefficient. The total torque value is obtained by multiplying the total required torque by the total torque reduction coefficient.

[0101] Torque gradient limiting: Gradient limiting is applied to the final calculated target torque to ensure smooth torque changes. In each control cycle, the torque change ΔT is calculated: ΔT = T_target_current - T_target_previous

[0102] If ΔT is greater than the upper bound gradient ΔT_max (calibrated value), then T_target_current = T_target_previous + ΔT_max; if ΔT is less than the lower bound gradient ΔT_min (calibrated value), then T_target_current = T_target_previous + ΔT_min.

[0103] It is understandable that the gradient limit value is calibrated based on the vehicle's acceleration performance and comfort.

[0104] This step is the final execution, utilizing the torque reduction coefficient from step S30 and the enable state from step S40 to output the actual torque command. The distinction between drive types ensures the solution is applicable to different vehicle configurations. Gradient limiting further smooths the torque output.

[0105] The present invention provides a vehicle active anti-skid method that obtains the speed difference between the left and right wheels of the front and rear axles; obtains the target wheel speed difference during normal steering; obtains a torque reduction coefficient based on the speed difference between the left and right wheels of the front and rear axles and the target wheel speed difference; determines the activation state of the anti-skid function based on vehicle speed, required torque, and wheel speed signals; and obtains the final target torque of the front and rear axles based on the torque reduction coefficient and the activation state. This method can automatically prevent slippage when starting with high throttle on wet and slippery roads, and can achieve consistent wheel speeds on the same axle without the need for a differential lock, avoiding single-wheel slippage, and does not affect the function of the differential during steering.

[0106] Please see Figure 2 The present invention also provides a vehicle active anti-skid system. It is applied to the vehicle active anti-skid method provided in the above embodiments, and specifically includes:

[0107] The first speed difference unit is used to obtain the speed difference between the left and right wheels of the front and rear axles.

[0108] In this embodiment, the difference in wheel speed between the front and rear axles is obtained, and filtering is used to reduce the impact of slippage-induced fluctuations. Specifically, the implementation includes the following methods:

[0109] Wheel speed difference calculation: For the front axle, calculate the difference between the left wheel speed (v_left_front) and the right wheel speed (v_right_front), and take the absolute value: Δv_front = |v_left_front - v_right_front|; for the rear axle, calculate the difference between the left wheel speed (v_left_rear) and the right wheel speed (v_right_rear), and take the absolute value: Δv_rear = |v_left_rear - v_right_rear|. Wheel speed signals usually come from wheel speed sensors, and the accuracy and real-time performance of the signals must be ensured.

[0110] Furthermore, a first-order low-pass filter is used to smooth the wheel speed difference. The filter's transfer function is: Δv_filtered(k) = α * Δv(k) + (1-α) * Δv_filtered(k-1), where Δv(k) is the current wheel speed difference, Δv_filtered(k) is the filtered wheel speed difference, and α is the filter coefficient (given by calibration, typically ranging from 0 to 1). The initial value Δv_filtered(0) is set to the actual wheel speed difference Δv(0). The selection of the filter coefficient α depends on the vehicle's dynamic characteristics and is generally determined experimentally to balance response speed and smoothness.

[0111] Understandably, this step provides the foundational data for subsequent torque reduction coefficient calculations. Filtering ensures the stability of wheel speed differences, preventing control jitter caused by instantaneous fluctuations.

[0112] The second wheel speed difference unit is used to obtain the target wheel speed difference during normal steering.

[0113] In this embodiment, the difference in wheel speed between the inner and outer wheels during normal steering is estimated to distinguish between normal steering and slippage. The specific implementation is as follows:

[0114] Target yaw rate lookup table: Using steering wheel angle δ (unit: degrees or radians) and vehicle speed v (unit: km / h or m / s) as input, the target yaw rate ω_t (unit: rad / s) is looked up through a pre-calibrated interpolation table. This interpolation table is calibrated through a sinusoidal sweep frequency test: Under various combinations of vehicle speed and steering wheel angle, the actual yaw rate of the vehicle is measured to establish a two-dimensional mapping of ω_t=f(δ,v). Linear interpolation or spline interpolation is used to improve accuracy during lookup.

[0115] Target wheel speed difference calculation: Based on the target yaw rate ω_t and wheelbase L (unit: m, vehicle fixed parameter), calculate the inner and outer target wheel speed difference Δv_wt: Δv_wt = ω_t * L. This formula is based on vehicle steering geometry and represents the difference in linear velocity between the inner and outer wheels to meet steering requirements.

[0116] Understandably, this step provides a reference wheel speed difference during normal steering, which is compared with the actual filtered wheel speed difference in step S10 to identify slippage. If the actual wheel speed difference is much greater than the target wheel speed difference, it indicates that slippage may be occurring.

[0117] The torque reduction coefficient unit is used to obtain the torque reduction coefficient based on the speed difference between the left and right wheels of the front and rear axles and the target wheel speed difference.

[0118] In this embodiment, the torque reduction coefficient is calculated based on the deviation between the actual wheel speed difference and the target wheel speed difference, and its rate of change is limited to avoid torque fluctuations. Specific implementation method:

[0119] Torque reduction coefficient lookup table: For the front axle, use the filtered wheel speed difference Δv_front_filtered and the target wheel speed difference Δv_wt to look up the table to obtain the front axle virtual differential lock torque reduction coefficient K_front. The table lookup input can be the wheel speed difference ratio (Δv_front_filtered / Δv_wt) or the difference (Δv_front_filtered-Δv_wt), the specific form of which is determined by calibration.

[0120] For the rear axle, the torque reduction coefficient K_rear is also obtained by looking up tables using Δv_rear_filtered and Δv_wt. The table content is calibrated through bench or real vehicle testing, and is typically designed such that: when the actual wheel speed difference is close to the target wheel speed difference, the torque reduction coefficient is close to 1 (no torque reduction); when the actual wheel speed difference is large, the torque reduction coefficient decreases. Gradient limiting processing: The torque reduction coefficient K is subject to gradient limiting to ensure its smooth change. For each control cycle (e.g., 10ms), the change in torque reduction coefficient ΔK is calculated: ΔK = K_current - K_previous

[0121] If ΔK is greater than the upper bound gradient ΔK_max (calibrated value), then K_current = K_previous + ΔK_max; if ΔK is less than the lower bound gradient ΔK_min (calibrated value, usually negative), then K_current = K_previous + ΔK_min.

[0122] The gradient limit values ​​ΔK_max and ΔK_min are calibrated according to the characteristics of the vehicle's powertrain to avoid sudden torque changes.

[0123] Understandably, gradient limiting ensures smooth torque changes and improves driving comfort.

[0124] The judgment unit is used to determine the activation status of the anti-skid function based on vehicle speed, required torque, and wheel speed signals.

[0125] In this embodiment, the activation of the anti-slip function is determined based on the vehicle status signal, and hysteresis is incorporated to prevent frequent switching. Specific implementation method:

[0126] Acquire vehicle status signals: vehicle speed v, target torque T_req (from driver's throttle or controller), and validity signals of each wheel speed (Boolean value, indicating whether the wheel speed sensor is working properly).

[0127] Check the global anti-skid function activation indicator (which may come from the vehicle control system or driver switch).

[0128] For a given axle (front or rear), the anti-slip function is only allowed to be activated when both wheel speed signals for that axle are valid.

[0129] This embodiment obtains the vehicle speed, target torque requirement, and wheel speed validity signals. The anti-slip function is only allowed to be activated when the anti-slip function is enabled and the two wheel speed signals of a certain axle are valid. In addition, it is necessary to determine whether the vehicle speed and total torque requirement simultaneously meet the function activation conditions.

[0130] Furthermore, to avoid the situation of repeated enabling and disabling of functions caused by small fluctuations in vehicle speed and required torque, a hysteresis treatment is added. When the vehicle speed is greater than a certain upper limit value, enabling is allowed. When the vehicle speed is lower than a certain lower limit, enabling is turned off. If the vehicle speed is between the upper and lower limits, the enabling maintains the previous state value. Similarly, hysteresis treatment is also added to the required torque. Only when the anti-skid function activation is allowed and both the vehicle speed and the required torque allow enabling, is the activation of this function allowed. Specifically, it includes:

[0131] Vehicle speed hysteresis: Set the vehicle speed upper limit v_high and lower limit v_low (calibration values). If v > v_high, the vehicle speed enabling flag is set to True; if v < v_low, it is set to False; if v_low ≤ v ≤ v_high, the previous state is maintained.

[0132] Required torque hysteresis: Set the torque upper limit T_high and lower limit T_low (calibration values). If T_req > T_high, the torque enabling flag is set to True; if T_req < T_low, it is set to False; if T_low ≤ T_req ≤ T_high, the previous state is maintained.

[0133] For each axle, only when global activation is allowed, the wheel speed of this axle is valid, the vehicle speed enabling flag is True, and the torque enabling flag is True, is the anti-skid function of this axle activated.

[0134] When it is determined that the anti-skid function is activated (enabled): This "switch" closes, allowing the torque reduction coefficient to pass through. Next, K_used = K (i.e., the coefficient calculated in step S30, which may be less than 1) will be received. Finally, the target torque = required torque × K, achieving the effect of torque reduction and anti-skid.

[0135] When it is determined that the anti-skid function is not activated (not enabled): This "switch" disconnects and outputs a default value. Next, K_used = 1 will be received. Finally, the target torque = required torque × 1 = required torque, and the vehicle outputs full torque without the anti-skid function intervening.

[0136] It can be understood that this step is a safety logic to ensure that the anti-skid function is only activated under appropriate conditions (such as medium to high vehicle speeds and torque requirements), avoiding unnecessary intervention at low speeds or low torques. The hysteresis treatment enhances the system stability.

[0137] The output unit is used to obtain the final target torques of the front and rear axles according to the torque reduction coefficient and the activation state.

[0138] In this embodiment, according to the torque reduction coefficient and the enabling state, the target torque finally sent to the drive wheels is calculated, considering the drive type and the torque change gradient. The specific implementation method is as follows:

[0139] For each axis, if the anti-slip enable is activated, the torque reduction coefficient (K_front or K_rear) calculated in step S30 is used; otherwise, the torque reduction coefficient is set to 1.

[0140] Torque calculation for four-wheel drive vehicles: Front axle target torque T_front_target = min(T_front_req*K_front, T_front_max), where T_front_req is the required torque for the front axle (from the power distribution system), and T_front_max is the maximum torque capacity of the front axle (limited by the engine or electric motor). Rear axle target torque T_rear_target = min(T_rear_req*K_rear, T_rear_max), where T_rear_req is the required torque for the rear axle, and T_rear_max is the maximum torque capacity of the rear axle.

[0141] Understandably, for four-wheel drive vehicles, the required torque for the front axle is multiplied by the front axle torque reduction coefficient to obtain the target torque for the front axle. This target torque is then compared with the maximum capacity of the front axle, and the smaller value is taken as the front axle torque value. For the rear axle, the required torque for the rear axle is multiplied by the rear axle torque reduction coefficient to obtain the target torque for the rear axle. This target torque is then compared with the maximum capacity of the rear axle, and the smaller value is taken as the rear axle torque value.

[0142] Torque calculation for two-wheel drive vehicles: compare the torque reduction coefficients of the front and rear axles: K_total=min(K_front,K_rear), total target torque T_total_target=T_total_req*K_total, where T_total_req is the total required torque (directly from the driver's input).

[0143] It is understandable that for two-wheel drive vehicles, the torque reduction coefficients of the front and rear axles are compared and the smaller one is taken as the total torque reduction coefficient. The total torque value is obtained by multiplying the total required torque by the total torque reduction coefficient.

[0144] Torque gradient limiting: Gradient limiting is applied to the final calculated target torque to ensure smooth torque changes. In each control cycle, the torque change ΔT is calculated: ΔT = T_target_current - T_target_previous

[0145] If ΔT is greater than the upper bound gradient ΔT_max (calibrated value), then T_target_current = T_target_previous + ΔT_max; if ΔT is less than the lower bound gradient ΔT_min (calibrated value), then T_target_current = T_target_previous + ΔT_min.

[0146] It is understandable that the gradient limit value is calibrated based on the vehicle's acceleration performance and comfort.

[0147] The vehicle active anti-skid system provided by this invention acquires the speed difference between the left and right wheels of the front and rear axles; acquires the target wheel speed difference during normal steering; acquires a torque reduction coefficient based on the speed difference between the left and right wheels of the front and rear axles and the target wheel speed difference; determines the activation state of the anti-skid function based on vehicle speed, required torque, and wheel speed signals; and acquires the final target torque of the front and rear axles based on the torque reduction coefficient and the activation state. This method can automatically prevent slippage when starting with high throttle on wet and slippery roads, and can achieve consistent wheel speeds on the same axle without the need for a differential lock, avoiding single-wheel slippage, and does not affect the function of the differential during steering.

[0148] Based on the same inventive concept, embodiments of the present invention also provide an electronic device. Figure 3 This is a structural block diagram of an electronic device provided in an embodiment of the present invention. Figure 3 As shown, an embodiment of the present invention provides an electronic device including: one or more processors 101, a memory 102, and one or more I / O interfaces 103. The memory 102 stores one or more programs, which, when executed by the one or more processors, cause the one or more processors to implement any of the vehicle active anti-skid methods described in the above embodiments; the one or more I / O interfaces 103 are connected between the processor and the memory, configured to enable information interaction between the processor and the memory.

[0149] The processor 101 is a device with data processing capabilities, including but not limited to a central processing unit (CPU); the memory 102 is a device with data storage capabilities, including but not limited to random access memory (RAM, more specifically SDRAM, DDR, etc.), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), and flash memory (FLASH); the I / O interface (read / write interface) 103 is connected between the processor 101 and the memory 102, and can realize information interaction between the processor 101 and the memory 102, including but not limited to a data bus (Bus).

[0150] In some embodiments, the processor 101, memory 102, and I / O interface 103 are interconnected via bus 104, and thus connected to other components of the computing device.

[0151] In some embodiments, the one or more processors 101 include a field-programmable gate array.

[0152] This invention also provides a computer-readable medium. The computer-readable medium stores a computer program, which, when executed by a processor, implements the steps of any of the vehicle active anti-skid methods described in the above embodiments. The computer-readable storage medium may be volatile or non-volatile.

[0153] This invention also provides a computer program product, including computer-readable code, or a non-volatile computer-readable storage medium carrying computer-readable code. When the computer-readable code is run in the processor of an electronic device, the processor in the electronic device executes the above-described vehicle active anti-skid method.

[0154] Those skilled in the art will understand that all or some of the steps, systems, and apparatuses disclosed above, and their functional modules / units, can be implemented as software, firmware, hardware, or suitable combinations thereof. In hardware implementations, the division between functional modules / units mentioned above does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed collaboratively by several physical components. Some or all physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit (ASIC). Such software can be distributed on a computer-readable storage medium, which may include computer storage media (or non-transitory media) and communication media (or transient media).

[0155] As is known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information, such as computer-readable program instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), static random access memory (SRAM), flash memory or other memory technologies, portable compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, it is known to those skilled in the art that communication media typically contain computer-readable program instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0156] The computer-readable program instructions described herein can be downloaded from computer-readable storage media to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards them to the computer-readable storage media in the respective computing / processing device.

[0157] The computer program instructions used to perform the operations of this invention may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, etc., and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The computer-readable program instructions may be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, electronic circuitry, such as programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), is personalized by utilizing state information from the computer-readable program instructions. This electronic circuitry can execute the computer-readable program instructions to implement various aspects of the invention.

[0158] The computer program product described herein can be implemented specifically through hardware, software, or a combination thereof. In one alternative embodiment, the computer program product is specifically embodied in a computer storage medium; in another alternative embodiment, the computer program product is specifically embodied in a software product, such as a software development kit (SDK), etc.

[0159] Various aspects of the present invention are described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer-readable program instructions.

[0160] These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that, when executed by the processor of the computer or other programmable data processing apparatus, they create means for implementing the functions / actions specified in one or more blocks of the flowchart and / or block diagram. These computer-readable program instructions can also be stored in a computer-readable storage medium that causes a computer, programmable data processing apparatus, and / or other device to operate in a particular manner; thus, the computer-readable medium storing the instructions comprises an article of manufacture that includes instructions for implementing aspects of the functions / actions specified in one or more blocks of the flowchart and / or block diagram.

[0161] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the instructions executed on the computer, other programmable data processing apparatus, or other device to perform the functions / actions specified in one or more boxes of a flowchart and / or block diagram.

[0162] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of an instruction, which contains one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than those shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0163] Example embodiments have been disclosed herein, and while specific terminology has been used, it is for illustrative purposes only and should be construed as such, and is not intended to be limiting. In some instances, it will be apparent to those skilled in the art that features, characteristics, and / or elements described in conjunction with particular embodiments may be used alone, or in combination with features, characteristics, and / or elements described in conjunction with other embodiments, unless otherwise expressly indicated. Therefore, those skilled in the art will understand that various changes in form and detail may be made without departing from the scope of the invention as set forth in the appended claims.

Claims

1. A method for active anti-skid operation of vehicles, characterized in that, It includes: Obtain the left and right wheel speed differences of the front and rear axles; Obtain the target wheel speed difference during normal steering; Obtain the torque reduction coefficient according to the left and right wheel speed differences of the front and rear axles and the target wheel speed difference; Determine the activation state of the anti-skid function based on vehicle speed, required torque, and wheel speed signals; Obtain the final target torques of the front and rear axles according to the torque reduction coefficient and the activation state.

2. The active anti-skid method for vehicles according to claim 1, characterized in that, In the step of obtaining the left and right wheel speed differences of the front and rear axles, it includes: For the front axle, calculate the difference between the left wheel speed v_left_front and the right wheel speed v_right_front, and take the absolute value: Δv_front = |v_left_front - v_right_front| For the rear axle, calculate the difference between the left wheel speed v_left_rear and the right wheel speed v_right_rear, and take the absolute value: Δv_rear = |v_left_rear - v_right_rear| Smooth the wheel speed difference using a first-order low-pass filter.

3. The active anti-skid method for vehicles according to claim 1, characterized in that, In the step of obtaining the target wheel speed difference during normal steering, it includes: Take the steering wheel angle δ and vehicle speed v as inputs, and query the target yaw rate ω_t through a pre-calibrated interpolation table; This interpolation table is calibrated through a sine sweep test: measure the actual yaw rate of the vehicle under various combinations of vehicle speeds and steering wheel angles, and establish a two-dimensional mapping table of ω_t = f(δ, v); According to the target yaw rate ω_t and wheelbase L, calculate the inner and outer target wheel speed difference Δv_wt: Δv_wt = ω_t * L.

4. The active anti-skid method for vehicles according to claim 1, characterized in that, In the step of obtaining the torque reduction coefficient according to the left and right wheel speed differences of the front and rear axles and the target wheel speed difference, it includes: For the front axle, use the filtered wheel speed difference Δv_front_filtered and the target wheel speed difference Δv_wt, and look up the table to obtain the front axle virtual differential lock torque reduction coefficient K_front; For the rear axle, use Δv_rear_filtered and Δv_wt to look up the table to obtain K_rear; Perform gradient limit on the torque reduction coefficient, that is, limit the change amount of the torque reduction coefficient in each calculation cycle.

5. The active anti-skid method for vehicles according to claim 1, characterized in that, In the step of determining the activation state of the anti-skid function based on vehicle speed, required torque, and wheel speed signals, it includes: Obtain vehicle state signals: vehicle speed v, target required torque T_req, and wheel speed validity signals for each wheel; Check the global allow anti-skid function activation flag; For a certain axle, the anti-skid function of this axle is only allowed to be activated when the wheel speed signals of both wheels of this axle are valid.

6. The active anti-skid method for vehicles according to claim 5, characterized in that, It also includes the following steps: hysteresis processing of vehicle speed and required torque, including: Vehicle speed hysteresis: Set the vehicle speed upper limit v_high and lower limit v_low; if v > v_high, then set the vehicle speed enable flag to True; if v < v_low, then set it to False; if v_low ≤ v ≤ v_high, then maintain the previous state; Demand torque hysteresis: Set the torque upper limit T_high and the lower limit T_low; if T_req > T_high, set the torque enable flag to True; if T_req < T_low, set it to False; if T_low ≤ T_req ≤ T_high, maintain the previous state; For each axle, the anti-skid function of the axle is activated only when global activation is allowed, the wheel speed of the axle is valid, the vehicle speed enable flag is True, and the torque enable flag is True.

7. The active anti-skid method for vehicles according to claim 1, characterized in that, In the step of obtaining the final front and rear axle target torques according to the torque reduction coefficient and the activation state, it includes: For each axle, if the anti-skid enable is activated, use the torque reduction coefficient of the axle, otherwise the torque reduction coefficient is 1; For four-wheel drive vehicles: Front axle target torque = min(front axle demand torque * front axle torque reduction coefficient, front axle maximum available torque); Rear axle target torque = min(rear axle demand torque * rear axle torque reduction coefficient, rear axle maximum available torque) For two-wheel drive vehicles: Compare the front and rear axle torque reduction coefficients, take the minimum value as the total torque reduction coefficient, and the total target torque = total demand torque * total torque reduction coefficient; Perform gradient limiting processing on the torque change to ensure smooth torque change.

8. A vehicle active anti-skid system, characterized in that, It includes: The first wheel speed difference unit is used to obtain the left and right wheel speed differences of the front and rear axles; The second wheel speed difference unit is used to obtain the target wheel speed difference during normal steering; The torque reduction coefficient unit is used to obtain the torque reduction coefficient according to the left and right wheel speed differences of the front and rear axles and the target wheel speed difference; The judgment unit is used to determine the activation state of the anti-skid function based on the vehicle speed, demand torque, and wheel speed signal; The output unit is used to obtain the final front and rear axle target torques according to the torque reduction coefficient and the activation state.

9. An electronic device, characterized in that, It includes: One or more processors; A memory for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the method according to any one of claims 1 to 7.

10. A computer-readable medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps in the method according to any one of claims 1 to 7.

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