Vehicle steering control method, device and vehicle

Abstract

The present application relates to a kind of vehicle steering control method, device and vehicle, the method comprises: in the case where the steering wheel angle of vehicle is detected to exceed preset angle, obtain the running parameter of vehicle, and determine whether running parameter satisfies preset steering condition, if yes, according to the corresponding relationship of the running parameter and the front and rear pressure difference value request stored in advance, determine target front and rear pressure difference value, according to target front and rear pressure difference value, correct current front and rear pressure difference value, control vehicle to steer.This embodiment of the present application judges the trend of vehicle to appear insufficient steering according to real-time running parameter, and uses to correct front and rear pressure difference value, to realize the increase of front wheel or rear wheel adhesion, can effectively reduce the steering difficulty and frequency of driver operation, improve the steering deficiency or steering excess problem of vehicle in various scenarios, to improve the comprehensive driving performance of vehicle.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle control, and in particular to a vehicle steering control method, device and vehicle. Background Art

[0002] With the development of vehicle control technology, the steering performance of vehicles has received widespread attention. Good steering performance will give the driver a better driving experience and reduce the fatigue caused by frequent operations.

[0003] At present, when a front-wheel drive car accelerates and turns, the driving force causes the lateral adhesion of the front wheels to decrease, resulting in understeer; rear-wheel drive cars have the opposite characteristics, which can also lead to oversteer. In this case, the driver will usually continuously correct the steering, or reduce the throttle and brake to ensure that the vehicle can complete the turn according to the established route.

[0004] However, the above-mentioned steering method needs to rely on the driver's operation to be implemented, and the operation is complicated, which will weaken the driver's confidence in turning. In addition, the frequent operation during steering increases the driver's turning operation burden and affects the driver's driving experience. Summary of the Invention

[0005] One of the purposes of the present invention is to provide a vehicle steering control method to solve the problem in the prior art that vehicle steering relies on the driver's operation and the operation is complicated; the second purpose is to provide a vehicle steering control device; the third purpose is to provide a vehicle.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A vehicle steering control method, the method comprising:

[0008] When detecting that the steering wheel angle of the vehicle exceeds a preset angle, obtaining driving parameters of the vehicle and determining whether the driving parameters meet a preset steering condition;

[0009] If yes, determining a target front and rear downforce difference value based on a pre-stored correspondence between the driving parameter and the front and rear downforce difference value request;

[0010] According to the target front and rear downforce difference, the current front and rear downforce difference is corrected to control the vehicle to steer.

[0011] Optionally, when detecting that the steering wheel angle of the vehicle exceeds a preset angle, obtaining driving parameters of the vehicle and determining whether the driving parameters meet preset steering conditions include:

[0012] When detecting that the steering wheel angle of the vehicle exceeds a preset angle, obtaining driving parameters of the vehicle, wherein the driving parameters include a brake signal, a gear position, a vehicle speed, a yaw rate, and an accelerator pedal opening;

[0013] If the braking signal and the gear change are not detected, it is determined whether the vehicle speed, the yaw rate, and the accelerator pedal opening are within a preset steering range.

[0014] Optionally, if so, determining the target front and rear downforce difference according to a pre-stored correspondence between the driving parameter and the front and rear downforce difference request includes:

[0015] If the vehicle speed and accelerator pedal opening are within a preset steering range, and the yaw rate is inconsistent with a preset steering target range, a pre-stored calibration map is consulted; wherein the calibration map stores a correspondence between the steering wheel angle, the yaw rate, and the front and rear downforce difference;

[0016] According to the steering wheel angle and the yaw rate, a corresponding target front and rear downforce difference is determined in the calibration map.

[0017] Optionally, the correcting the current front and rear downforce difference according to the target front and rear downforce difference to control the vehicle to turn includes:

[0018] If the vehicle's yaw rate is less than the preset steering target range, a front and rear downforce adjustment request is issued;

[0019] increasing the current front and rear downforce difference to the target front and rear downforce difference within a preset time period according to the front and rear downforce adjustment request, and controlling the vehicle to turn; or

[0020] If the vehicle's yaw rate is greater than the preset steering target range, a front and rear downforce adjustment request is issued;

[0021] According to the front and rear downforce adjustment request, the current front and rear downforce difference is reduced to the target front and rear downforce difference within a preset time period, and the vehicle is controlled to turn.

[0022] Optionally, before correcting the current front and rear downforce difference according to the target front and rear downforce difference and controlling the vehicle to turn, the method further includes:

[0023] If a gear change is detected or the accelerator pedal opening exceeds the preset steering range or the steering wheel angle returns to zero, an interrupt request is issued;

[0024] According to the interrupt request, the front and rear downforce difference is controlled to be restored to the current front and rear downforce difference.

[0025] A vehicle steering control device, comprising:

[0026] a parameter acquisition module, configured to acquire driving parameters of the vehicle when detecting that the steering wheel angle of the vehicle exceeds a preset angle, and determine whether the driving parameters meet a preset steering condition;

[0027] a difference determination module, configured to determine a target front and rear downforce difference value based on a pre-stored correspondence between the driving parameters and the front and rear downforce difference value requests;

[0028] The steering control module is used to correct the current front and rear downforce difference according to the target front and rear downforce difference and control the vehicle to steer.

[0029] Optionally, the parameter acquisition module includes:

[0030] a parameter acquisition submodule, configured to acquire driving parameters of the vehicle when detecting that the steering wheel angle of the vehicle exceeds a preset angle, wherein the driving parameters include a brake signal, a gear position, a vehicle speed, a yaw angular velocity, and an accelerator pedal opening;

[0031] The judgment submodule is configured to judge whether the vehicle speed, the yaw rate and the accelerator pedal opening are within a preset steering range respectively if the braking signal and the gear change are not detected.

[0032] Optionally, the difference determination module includes:

[0033] a query submodule, configured to query a pre-stored calibration map table if the vehicle speed and accelerator pedal opening are within a preset steering range and the yaw rate is inconsistent with a preset steering target range; wherein the calibration map table stores a correspondence between the steering wheel angle, the yaw rate, and the front and rear downforce difference;

[0034] Optionally, the steering control module includes:

[0035] a first request submodule, configured to issue a front and rear downforce adjustment request if the vehicle's yaw rate is less than a preset steering target range;

[0036] a first control submodule, configured to increase the current front and rear downforce difference to the target front and rear downforce difference within a preset time period according to the front and rear downforce adjustment request, and control the vehicle to turn; or

[0037] a second request submodule, configured to issue a front and rear downforce adjustment request if the vehicle's yaw rate is greater than a preset steering target range;

[0038] The second control submodule is configured to reduce the current front and rear downforce difference to the target front and rear downforce difference within a preset time period according to the front and rear downforce adjustment request, thereby controlling the vehicle to turn.

[0039] Optionally, the device further comprises:

[0040] An interrupt request module is used to issue an interrupt request if a gear change or an accelerator pedal opening exceeds a preset steering range or a steering wheel angle is detected to be zero;

[0041] A control recovery module is used to control the front and rear downforce difference value to be restored to the current front and rear downforce difference value according to the interrupt request.

[0042] Beneficial effects of the present invention:

[0043] The vehicle steering control method provided by an embodiment of the present invention obtains vehicle driving parameters upon detecting that the vehicle's steering wheel angle exceeds a preset angle, and determines whether the driving parameters meet preset steering conditions. If so, a target front-to-rear downforce differential is determined based on a pre-stored correspondence between the driving parameters and a front-to-rear downforce differential request. Based on the target front-to-rear downforce differential, the current front-to-rear downforce differential is corrected to control the vehicle's steering. During a steering request, if the vehicle is understeering based on real-time driving parameters, the present embodiment uses the corrected front-to-rear downforce differential to increase front or rear wheel adhesion, thereby ensuring that the steering yaw torque meets the steering request and improving steering response. This effectively reduces the difficulty and frequency of steering operations for the driver, enhances the smoothness and driving experience, and proactively adjusts front and rear downforce to mitigate understeer or oversteer in various scenarios, thereby improving the vehicle's overall driving performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is one of the step flow charts of a vehicle steering control method provided by an embodiment of the present invention;

[0045] Figure 2 yes Figure 1 A method flow chart of step 101 of the vehicle steering control method provided by an embodiment of the present invention;

[0046] Figure 3 yes Figure 1 A method flow chart of step 102 of the vehicle steering control method provided by an embodiment of the present invention;

[0047] Figure 4 yes Figure 1 A method flow chart of step 103 of the vehicle steering control method provided by an embodiment of the present invention;

[0048] Figure 5 yes Figure 1 Schematic diagram of adjusting the front and rear downforce difference in the vehicle steering control method provided by the embodiment of the present invention Figure 1 ;

[0049] Figure 6 yes Figure 1 Schematic diagram of adjusting the front and rear downforce difference in the vehicle steering control method provided by the embodiment of the present invention Figure 2 ;

[0050] Figure 7 yes Figure 1 Schematic diagram of adjusting the front and rear downforce difference in the vehicle steering control method provided by the embodiment of the present invention Figure 3 ;

[0051] Figure 8 This is the second step flow chart of a vehicle steering control method provided by an embodiment of the present invention;

[0052] Figure 9 is a flow chart of a vehicle steering control method provided by an embodiment of the present invention;

[0053] Figure 10 It is a structural schematic diagram of a vehicle steering control device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0054] The following describes the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art will readily appreciate the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the various details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are intended only to illustrate the present invention and are not intended to limit the scope of protection of the present invention.

[0055] Reference Figure 1 , shows one of the flow charts of the vehicle steering control method provided by an embodiment of the present invention, the method may include:

[0056] Step 101 : When it is detected that the steering wheel angle of the vehicle exceeds a preset angle, the driving parameters of the vehicle are obtained, and it is determined whether the driving parameters meet the preset steering conditions.

[0057] In an embodiment of the present invention, when a vehicle decelerates appropriately while turning, the lateral force on the front axle increases and the lateral force on the rear axle decreases, forming a yaw moment in the same direction as the vehicle's steering direction, which helps the vehicle steer and causes the vehicle to oversteer. Similarly, if the vehicle accelerates appropriately, the lateral force on the front axle decreases and the lateral force on the rear axle increases, forming a yaw moment in the opposite direction of the vehicle's steering direction, which hinders the vehicle's steering and causes the vehicle to understeer. In order to solve the problem of vehicle understeer or oversteer causing driver difficulty in operation, this embodiment of the invention uses the front and rear downforce difference to change the front and rear axle loads of the vehicle after detecting that the vehicle has entered the set steering condition, thereby improving and reducing the vehicle's understeer or oversteer tendency, improving the driving smoothness in steering operation, and actively reducing the frequency of the driver's active steering wheel operation.

[0058] In an embodiment of the present invention, the vehicle's ECU determines whether the vehicle enters a preset steering condition by monitoring the vehicle parameters in real time. That is, when the ECU detects that the vehicle's steering wheel angle exceeds a preset angle, it obtains the vehicle's driving parameters and determines whether the driving parameters meet the preset steering conditions.

[0059] Specifically, the ECU is based on the CAN bus and reads the steering wheel angle in real time through the steering wheel angle sensor installed in the steering system. The ECU also reads the vehicle driving parameters that can be directly measured or indirectly estimated and stored in the processor chip, including the vehicle's braking signal, gear position, vehicle speed, yaw angular velocity and accelerator pedal opening.

[0060] In this embodiment, the ECU determines the vehicle's steering condition by comprehensively analyzing vehicle speed, yaw rate, accelerator pedal opening, brake signal, and gear position. Therefore, the preset steering conditions may include the following: yaw rate not meeting the target range, vehicle speed meeting the set range, gear position unchanged, accelerator pedal opening within the effective range, and no brake signal issued. It should be noted that the effective speed requirements may include 40 kph-120 kph, gear position Gt unchanged, yaw rate not meeting the target range ±5%, accelerator pedal opening greater than 5%, and brake signal OFF. Of course, the set values ​​for vehicle speed, yaw rate, accelerator pedal opening, steering wheel angle, etc. in the above embodiment are merely illustrative. Manufacturers may adjust these settings based on vehicle performance. This embodiment does not impose specific limits on these ranges.

[0061] Step 102: If yes, determine the target front and rear downforce difference based on the pre-stored correspondence between the driving parameters and the front and rear downforce difference requests.

[0062] In an embodiment of the present invention, if the driving parameters satisfy a preset turning condition, a target front-to-rear downforce difference is determined based on the current driving parameters by searching the pre-stored correspondence between the driving parameters and the requested front-to-rear downforce difference. Front-to-rear downforce is defined as the force acting on the vehicle body and transmitted to the vehicle wheels in response to the aerodynamic characteristics of the vehicle body when traveling at a known vehicle speed. This includes the aerodynamic forces acting on the front and / or rear spoiler assemblies equipped on the vehicle. The front-to-rear downforce difference is the difference between the front and rear axle downforce values ​​and can be negative, affecting tire friction and, therefore, the vehicle's traction. The vehicle's active aerodynamic control system can control downforce by controlling the positions of the front and rear spoiler assemblies, though this embodiment is not particularly limited to this.

[0063] Specifically, when the driving parameters meet the preset steering conditions, the ECU determines the front and rear downforce difference. Based on the current steering angle, yaw rate, and a pre-calibrated and stored calibration map, the ECU performs a table lookup to determine a desired front and rear downforce difference. The desired front and rear downforce difference, or target front and rear downforce difference, is the difference between the front axle downforce value and the rear axle downforce value, and may be a negative value. This calibration map is derived from extensive test data. The process for obtaining the calibration map is not detailed in this embodiment; however, it may be any table that ensures optimal front and rear downforce requirements for different steering angles and yaw rate responses.

[0064] Step 103 : According to the target front and rear downforce difference, the current front and rear downforce difference is corrected, and the vehicle is controlled to steer.

[0065] In an embodiment of the present invention, after determining the target front and rear downforce difference, the vehicle ECU executes the target front and rear downforce difference request. After the preset action time is completed, the current front and rear downforce difference is corrected to restore the front and rear downforce and control the vehicle to turn.

[0066] Specifically, when the vehicle's yaw rate is less than the steering request and falls short of the desired target range by 5%, indicating a slow steering response with a tendency toward understeering, the front-to-rear downforce differential is increased to increase front wheel adhesion, enhance the steering yaw torque, and improve steering response. When the vehicle's yaw rate is greater than the steering request and falls short of the desired target range by 5%, indicating a rapid steering response with a tendency toward oversteering, the front-to-rear downforce differential is reduced to increase rear wheel adhesion, reduce the steering yaw torque, and correct the steering response. This reduces the difficulty and frequency of steering operations for the driver, making driving the vehicle easier and smoother.

[0067] For example, refer to Figures 5 to 7, shows a schematic diagram of adjusting the front and rear downforce difference in the vehicle steering control method provided by an embodiment of the present invention, such as Figure 5 As shown in the figure, when the yaw rate is positive and greater than 5% of the target range, the ECU queries the calibration map and issues a front and rear downforce adjustment request. The request includes a requested difference and a preset action time. The front and rear downforce difference will decrease according to the request to increase the rear axle downforce ratio until the preset action time is completed and the front and rear downforce difference is restored. Figure 6 As shown in the figure, when the yaw rate is negative and less than 5% of the target range, the ECU queries the calibration map and issues a front and rear downforce adjustment request. The front and rear downforce difference increases with the request to increase the front axle downforce ratio until the preset action time is completed and the front and rear downforce difference is restored. Figure 7 As shown in the figure, if a gear change is detected during the front and rear downforce adjustment request, or the accelerator pedal opening angle changes by more than 5%, or the steering wheel angle returns to zero, the ECU will issue an interrupt request and the front and rear downforce difference will be restored in advance.

[0068] It should be noted that the preset action time is the time for correcting the current front and rear downforce difference. In this embodiment, the preset action time can be any time within 50ms. The above is only a specific example. In actual application, it can also be modified by professional matching and debugging engineers based on the vehicle's own power characteristics, tire characteristics, and suspension characteristics. This embodiment does not specifically limit the length of the preset action time.

[0069] The vehicle steering control method provided by an embodiment of the present invention obtains vehicle driving parameters upon detecting that the vehicle's steering wheel angle exceeds a preset angle, and determines whether the driving parameters meet preset steering conditions. If so, a target front-to-rear downforce differential is determined based on a pre-stored correspondence between the driving parameters and a front-to-rear downforce differential request. Based on the target front-to-rear downforce differential, the current front-to-rear downforce differential is corrected to control the vehicle's steering. During a steering request, if the vehicle is understeering based on real-time driving parameters, the present embodiment uses the corrected front-to-rear downforce differential to increase front or rear wheel adhesion, thereby ensuring that the steering yaw torque meets the steering request and improving steering response. This effectively reduces the difficulty and frequency of steering operations for the driver, enhances the smoothness and driving experience, and proactively adjusts front and rear downforce to mitigate understeer or oversteer in various scenarios, thereby improving the vehicle's overall driving performance.

[0070] Further, refer to Figure 2 , Figure 2 yes Figure 1The method flow chart of step 101 of the vehicle steering control method provided by an embodiment of the present invention includes: step 101, when detecting that the steering wheel angle of the vehicle exceeds a preset angle, obtaining the driving parameters of the vehicle and determining whether the driving parameters meet the preset steering conditions, including:

[0071] Step 1011: When it is detected that the steering wheel angle of the vehicle exceeds a preset angle, the driving parameters of the vehicle are obtained, where the driving parameters include a brake signal, a gear position, a vehicle speed, a yaw angular velocity, and an accelerator pedal opening.

[0072] In an embodiment of the present invention, the ECU detects changes in the vehicle's steering angle signal once every preset time interval. When the ECU detects that the vehicle's steering wheel angle exceeds a preset angle, it obtains the vehicle's driving parameters. When the steering angle signal exceeds the preset angle, the next step of judgment is performed. Otherwise, after the end of this detection time interval, the vehicle's steering wheel angle signal is detected again after a preset time interval.

[0073] Specifically, the preset time interval can be 50ms, and the time interval for detecting a change in the direction angle signal is 30ms-60ms. The preset time interval can be 50ms, and the time interval for detecting a change in the direction angle signal is 30ms-60ms. The driving parameters include braking signal, gear, vehicle speed, yaw angular velocity and accelerator pedal opening.

[0074] It should be noted that the vehicle ECU is connected to the vehicle's braking system to obtain parameters such as vehicle speed signals, brake signals, gear position, yaw angular velocity and accelerator pedal opening input through vehicle speed sensors, brake controllers, etc.

[0075] Step 1012: If no braking signal and gear change are detected, it is determined whether the vehicle speed, yaw rate and accelerator pedal opening are within a preset steering range.

[0076] In an embodiment of the present invention, to ensure vehicle driving performance, front and rear downforce adjustment control is subject to limited operating conditions. If the ECU does not detect a gear change and does not receive a brake signal, it determines whether the vehicle speed, yaw rate, and accelerator pedal position are within a preset steering range. Specifically, the vehicle speed requirement is 40 kph-120 kph, the yaw rate does not meet the desired target range by ±5%, and the accelerator pedal position is greater than 5%. The set values ​​for the vehicle speed, yaw rate, accelerator pedal position, etc. in the above embodiment are merely illustrative and are not uniquely defined. Manufacturers may adjust these ranges based on vehicle performance.

[0077] In an embodiment of the present invention, when it is detected that the vehicle's steering wheel angle exceeds a preset angle, the vehicle's driving parameters are obtained. If no braking signal or gear change is detected, the vehicle speed, yaw angular velocity, and accelerator pedal opening are determined to be within a preset steering range. When the vehicle needs to turn, the vehicle's understeering trend is determined based on the real-time driving parameters, thereby achieving timely and effective correction of the front and rear downforce difference.

[0078] Further, refer to Figure 3 , Figure 3 yes Figure 1 The method flow chart of step 102 of the vehicle steering control method provided by an embodiment of the present invention includes: step 102, when detecting that the steering wheel angle of the vehicle exceeds a preset angle, obtaining the driving parameters of the vehicle and determining whether the driving parameters meet the preset steering conditions, including:

[0079] Step 1021 : If the vehicle speed and the accelerator pedal opening are within the preset steering range, and the yaw rate is inconsistent with the preset steering target range, a pre-stored calibration map is searched.

[0080] Among them, the calibration map table stores the corresponding relationship between the steering wheel angle and yaw rate and the front and rear downforce difference;

[0081] In an embodiment of the present invention, when the ECU determines that the vehicle speed and accelerator pedal opening are within a preset steering range, and the vehicle speed and accelerator pedal opening are within the preset steering range, indicating that the preset steering conditions for front and rear downforce adjustment control are met, the ECU then queries a pre-stored calibration map based on the difference between the current steering wheel angle and yaw angular rate and the target range.

[0082] Specifically, the ECU detects vehicle speed and accelerator pedal opening via a vehicle speed sensor and brake controller. The preset steering range corresponds to the front and rear downforce adjustment control conditions set in accordance with driving parameters. In this embodiment, the preset steering range for vehicle speed and accelerator pedal opening can be a vehicle speed requirement of 40 kph-120 kph and an accelerator pedal opening greater than 5%. The target range for yaw angular velocity is pre-set based on actual steering requirements and is not specifically limited here.

[0083] It should be noted that the calibration map table stores the correspondence between the steering wheel angle, yaw rate and the front and rear downforce difference. The universal characteristic diagram of the current vehicle, namely the calibration map table, integrates the driving characteristics of the current vehicle in the engine's ECU. For the calibration map table, it is a characteristic MAP based on the steering wheel angle, yaw rate, and the front and rear downforce difference, which characterizes the mapping relationship between different steering wheel angles and yaw rates of the current vehicle and different front and rear downforce differences of the current vehicle. That is, the steering wheel angle and yaw rate of the current vehicle can be input, and the front and rear downforce difference of the current vehicle can be output. Among them, the calibration map table is obtained based on a large amount of repeated test data to ensure that at different steering wheel angles and different yaw rates, there are optimal front and rear downforce requirements.

[0084] Step 1022: Determine the corresponding target front and rear downforce difference in the calibration map based on the steering wheel angle and yaw rate.

[0085] In this embodiment of the present invention, the ECU determines the target front and rear downforce difference corresponding to the current steering wheel angle and yaw rate based on a calibration map that has been pre-calibrated and stored within the ECU. This map is then used to determine the front axle downforce value minus the rear axle downforce value. This allows the ECU to execute the target front and rear downforce difference request and restore the front and rear downforce after the action time has expired.

[0086] In an embodiment of the present invention, when a vehicle has a steering demand and it is determined based on real-time driving parameters that the vehicle has an understeering trend, the front and rear downforce can be actively adjusted to improve the understeering or oversteering problem of the vehicle in various scenarios, thereby improving the overall driving performance of the vehicle.

[0087] Further, refer to Figure 4 , Figure 4 yes Figure 1 The method flow chart of step 103 of the vehicle steering control method provided by an embodiment of the present invention includes: step 103, when detecting that the steering wheel angle of the vehicle exceeds a preset angle, obtaining the driving parameters of the vehicle and determining whether the driving parameters meet the preset steering conditions, including:

[0088] Step 1031 : If the yaw rate of the vehicle is less than the preset steering target range, a front and rear downforce adjustment request is issued.

[0089] In an embodiment of the present invention, during a vehicle steering request, if the vehicle's yaw rate is less than a preset steering target range, which may be less than 5% of the target range, indicating a slow steering response and a tendency toward understeering, a front and rear downforce adjustment request is issued to control the front and rear downforce difference.

[0090] Step 1032 : Based on the front and rear downforce adjustment request, the current front and rear downforce difference is increased to the target front and rear downforce difference within a preset time period, and the vehicle is controlled to turn.

[0091] Specifically, based on the front and rear downforce adjustment requests, the front and rear downforce difference is increased within a preset time period to reach the target front and rear downforce difference, thereby increasing the front wheel adhesion, improving the steering yaw torque, and improving the steering response.

[0092] Step 1033: If the yaw rate of the vehicle is greater than the preset steering target range, a front and rear downforce adjustment request is issued.

[0093] Specifically, when the vehicle's yaw rate is greater than the steering request, and the vehicle's yaw rate is greater than a preset steering target range, which may not meet the target range but is greater than 5% of the target range, that is, when the steering response is too fast and there is a tendency to oversteer, a front and rear downforce adjustment request is issued to request control of the front and rear downforce difference.

[0094] Step 1034 : Based on the front and rear downforce adjustment request, the current front and rear downforce difference is reduced to the target front and rear downforce difference within a preset time period, and the vehicle is controlled to turn.

[0095] Specifically, based on the front and rear downforce adjustment requests, the front and rear downforce difference is reduced within a preset time period to the target front and rear downforce difference, so as to increase rear wheel adhesion, reduce steering yaw torque, and correct steering response, thereby reducing the difficulty and frequency of steering operations by the driver, making steering of the vehicle easier and smoother.

[0096] In the embodiment of the present invention, when a vehicle has a steering demand, the front and rear downforce differences are corrected to increase the adhesion of the front or rear wheels, thereby making the steering yaw torque meet the steering demand and improving the steering response. This can effectively reduce the difficulty and frequency of steering operations for the driver, enhance the smoothness and driving experience of the vehicle, and can actively adjust the front and rear downforce to improve the understeer or oversteer problem of the vehicle in various scenarios, thereby improving the overall driving performance of the vehicle.

[0097] Reference Figure 8 , shows a second flow chart of a vehicle steering control method provided by an embodiment of the present invention. This method is basically the same as the vehicle steering control method provided by the first embodiment of the present invention. The difference is that, with reference to Figure 8 ,include:

[0098] Step 101 : When it is detected that the steering wheel angle of the vehicle exceeds a preset angle, the driving parameters of the vehicle are obtained, and it is determined whether the driving parameters meet the preset steering conditions.

[0099] Step 102: If yes, determine the target front and rear downforce difference based on the pre-stored correspondence between the driving parameters and the front and rear downforce difference requests.

[0100] Step 104 : If it is detected that the gear position changes or the accelerator pedal opening exceeds the preset steering range or the steering wheel angle returns to zero, an interrupt request is issued.

[0101] In an embodiment of the present invention, to ensure that vehicle steering meets real-time driving changes and provide the driver with a better driving experience, when one of the following situations occurs during the front and rear downforce difference request, the front and rear downforce difference control is automatically terminated and the next steering wheel angle monitoring is entered to apply to more scenarios.

[0102] Specifically, if the ECU detects that the gear position has changed, the accelerator pedal opening exceeds the preset steering range, or the steering wheel angle has returned to zero, an interrupt request is issued to automatically end the front and rear downforce difference control.

[0103] Step 105 : According to the interrupt request, the front and rear downforce difference is controlled to be restored to the current front and rear downforce difference.

[0104] Step 103 : According to the target front and rear downforce difference, the current front and rear downforce difference is corrected, and the vehicle is controlled to steer.

[0105] The above steps 101-103 are described in the first embodiment of the present invention and will not be repeated here.

[0106] It should be noted that this embodiment does not limit the specific execution location of steps 104 and 105. For ease of understanding, this embodiment uses the example of steps 104 and 105 being executed after step 102 and before step 103. In actual use, steps 104 and 105 can also be completed as a single step, and each case will not be described in detail here.

[0107] Compared with the prior art, the embodiments of the present invention utilize front and rear downforce to change the load on the front and rear axles of the vehicle, increase or decrease the vehicle's yaw moment, achieve controllable understeer or oversteer trends, realize steering characteristics that meet the driver's expectations, and improve the smoothness and ease of driving the vehicle.

[0108] In order to enable those skilled in the art to more clearly understand the overall process of the vehicle steering control method disclosed in the above embodiment of the present invention, refer to Figure 9 The flowchart of the vehicle steering control method is used as an example to illustrate.

[0109] Step 201: Detect the steering wheel angle of the vehicle.

[0110] Specifically, the ECU detects changes in the steering wheel angle signal every 50ms and regularly detects the steering wheel angle of the vehicle.

[0111] Step 202: Determine whether the steering wheel angle exceeds a preset angle.

[0112] In this embodiment, when the steering wheel angle signal exceeds a preset angle, the process proceeds to the next step 203 to control the start of front and rear downforce determination and perform front and rear downforce control. The preset angle can be selected as 10°.

[0113] Step 203, determining the downforce before and after control startup.

[0114] Step 204: Determine whether the driving parameters meet the preset turning conditions.

[0115] Specifically, to ensure vehicle driving performance, front and rear downforce adjustment control is subject to limited operating conditions, including: the vehicle speed V is required to be between 40 kph and 120 kph, the target gear position Gt remains unchanged, the yaw rate does not meet the desired target range by 5% or less, the accelerator pedal opening Ap is greater than 5%, and the brake signal Br is OFF. If the ECU determines these signal requirements, it proceeds to step 205 to perform front and rear downforce control. Otherwise, it returns to step 201 to detect the vehicle's steering wheel angle at the next preset time interval.

[0116] Step 205 : query the pre-stored calibration map and send a front and rear downforce adjustment request.

[0117] Specifically, the ECU queries a pre-stored calibration map based on the difference between the current steering wheel angle and yaw rate (Yaw) and the target range to determine the target front and rear downforce difference and then sends a front and rear downforce adjustment request. This calibration map is derived from extensive test data to ensure optimal front and rear downforce requirements for different steering angles and yaw rates.

[0118] Step 206: Correct the front and rear downforce difference.

[0119] Specifically, if the yaw rate is positive and greater than the target range by 5%, the ECU issues a front / rear downforce adjustment request, Dr. This request, Dr, includes a requested difference and an action time. The front / rear downforce difference, Dfr, decreases in response to the request, increasing the rear axle downforce ratio until the action time is complete, restoring the front / rear downforce difference.

[0120] Step 207 , determining whether a gear change occurs or the accelerator pedal opening exceeds a preset steering range or the steering wheel angle returns to zero.

[0121] Specifically, if a change in the gear position Gt is detected during the front and rear downforce adjustment request, the accelerator pedal opening Ap changes by more than 5%, or the steering wheel angle signal Sta returns to zero, the ECU will issue an interrupt request Dir, and the front and rear downforce difference Dfr will automatically return to normal in advance.

[0122] Step 208: Send an interrupt request to interrupt the correction of the front and rear downforce difference.

[0123] Specifically, when one of the following set conditions occurs during the front and rear downforce request process, the front and rear downforce control is automatically terminated and the next steering wheel angle monitoring program is entered.

[0124] Step 209 : Control the front and rear downforce difference to return to the current front and rear downforce difference.

[0125] Specifically, a request for a target front and rear downforce difference is detected and executed, and after the request is completed, the front and rear downforce difference is controlled to be restored to the current front and rear downforce difference.

[0126] Compared with the prior art, the embodiments of the present invention utilize the front and rear downforce difference correction to increase the adhesion of the front or rear wheels when the vehicle is judged to have an understeering tendency based on real-time driving parameters during a steering demand, so that the steering yaw moment meets the steering demand and the steering response is improved. This can effectively reduce the difficulty and frequency of the driver's steering operations, improve the smoothness and experience of driving the vehicle, and can actively adjust the front and rear downforce to improve the understeering or oversteering problems of the vehicle in various scenarios, thereby improving the overall driving performance of the vehicle.

[0127] Reference Figure 10 , which shows a schematic structural diagram of a vehicle steering control device provided by an embodiment of the present invention, the device may include:

[0128] The parameter acquisition module 301 is configured to acquire the vehicle's driving parameters when detecting that the vehicle's steering wheel angle exceeds a preset angle, and determine whether the driving parameters meet a preset steering condition;

[0129] a difference determination module 302 for determining a target front and rear downforce difference based on a pre-stored correspondence between the driving parameters and the front and rear downforce difference requests;

[0130] The steering control module 303 is used to correct the current front and rear downforce difference according to the target front and rear downforce difference, and control the vehicle to steer.

[0131] Optionally, the parameter acquisition module 301 includes:

[0132] a parameter acquisition submodule, configured to acquire driving parameters of the vehicle when detecting that the steering wheel angle of the vehicle exceeds a preset angle, wherein the driving parameters include a brake signal, a gear position, a vehicle speed, a yaw angular velocity, and an accelerator pedal opening;

[0133] The judgment submodule is configured to judge whether the vehicle speed, the yaw rate and the accelerator pedal opening are within a preset steering range respectively if the braking signal and the gear change are not detected.

[0134] Optionally, the difference determination module 302 includes:

[0135] a query submodule, configured to query a pre-stored calibration map table if the vehicle speed and accelerator pedal opening are within a preset steering range and the yaw rate is inconsistent with a preset steering target range; wherein the calibration map table stores a correspondence between the steering wheel angle, the yaw rate, and the front and rear downforce difference;

[0136] Optionally, the steering control module 303 includes:

[0137] a first request submodule, configured to issue a front and rear downforce adjustment request if the vehicle's yaw rate is less than a preset steering target range;

[0138] a first control submodule, configured to increase the current front and rear downforce difference to the target front and rear downforce difference within a preset time period according to the front and rear downforce adjustment request, and control the vehicle to turn; or

[0139] a second request submodule, configured to issue a front and rear downforce adjustment request if the vehicle's yaw rate is greater than a preset steering target range;

[0140] The second control submodule is configured to reduce the current front and rear downforce difference to the target front and rear downforce difference within a preset time period according to the front and rear downforce adjustment request, thereby controlling the vehicle to turn.

[0141] Optionally, the device further comprises:

[0142] An interrupt request module is used to issue an interrupt request if a gear change or an accelerator pedal opening exceeds a preset steering range or a steering wheel angle is detected to be zero;

[0143] A control recovery module is used to control the front and rear downforce difference value to be restored to the current front and rear downforce difference value according to the interrupt request.

[0144] The specific implementation method of the vehicle steering control device provided in this embodiment can refer to the content of the vehicle steering control method provided in this embodiment, and will not be repeated here.

[0145] The vehicle steering control device provided in an embodiment of the present invention obtains vehicle driving parameters upon detecting that the vehicle's steering wheel angle exceeds a preset angle, and determines whether the driving parameters meet preset steering conditions. If so, the device determines a target front-to-rear downforce differential value based on a pre-stored correspondence between the driving parameters and a front-to-rear downforce differential value request. Based on the target front-to-rear downforce differential value, the current front-to-rear downforce differential value is corrected to control the vehicle's steering. During a steering request, if the vehicle is understeering based on real-time driving parameters, the device corrects the front-to-rear downforce differential value to increase front or rear wheel adhesion, thereby ensuring that the steering yaw torque meets the steering request and improving steering response. This effectively reduces the difficulty and frequency of steering operations for the driver, enhancing the smoothness and driving experience. Furthermore, the device can actively adjust the front and rear downforce values ​​to mitigate understeer or oversteer in various scenarios, thereby improving the vehicle's overall driving performance.

[0146] Based on the above vehicle steering control method, an embodiment of the present invention further provides a vehicle, comprising: a vehicle steering control device in the above steps, configured to execute the vehicle steering control method described in the above steps.

[0147] It can be understood that the vehicle shown in this application can be various types of vehicles with front and rear downforce adjustable devices, and the vehicle steering control method proposed in this application can be applied to these various types of vehicles.

[0148] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0149] Each embodiment in this specification is described in a related manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences between the other embodiments. In particular, the system embodiment is generally similar to the method embodiment, so the description is relatively simple. For related parts, refer to the description of the method embodiment.

[0150] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention are included in the scope of protection of the present invention.

Claims

1. A vehicle steering control method, characterized in that: The method comprises: When detecting that the steering wheel angle of the vehicle exceeds a preset angle, obtaining driving parameters of the vehicle and determining whether the driving parameters meet a preset steering condition; If yes, determining a target front and rear downforce difference value based on a pre-stored correspondence between the driving parameter and the front and rear downforce difference value request; According to the target front and rear downforce difference, the current front and rear downforce difference is corrected to control the vehicle to steer.

2. The method according to claim 1, characterized in that The method of obtaining a driving parameter of the vehicle and determining whether the driving parameter satisfies a preset steering condition when detecting that the steering wheel angle of the vehicle exceeds a preset angle includes: When detecting that the steering wheel angle of the vehicle exceeds a preset angle, obtaining driving parameters of the vehicle, wherein the driving parameters include a brake signal, a gear position, a vehicle speed, a yaw rate, and an accelerator pedal opening; If the braking signal and the gear change are not detected, it is determined whether the vehicle speed, the yaw rate, and the accelerator pedal opening are within a preset steering range.

3. The method according to claim 2, characterized in that If so, determining a target front and rear downforce difference value based on a pre-stored correspondence between the driving parameters and the front and rear downforce difference value request includes: If the vehicle speed and accelerator pedal opening are within a preset steering range, and the yaw rate is inconsistent with a preset steering target range, a pre-stored calibration map is consulted; wherein the calibration map stores a correspondence between the steering wheel angle, the yaw rate, and the front and rear downforce difference; According to the steering wheel angle and the yaw rate, a corresponding target front and rear downforce difference is determined in the calibration map.

4. The method according to claim 3, characterized in that The method of correcting the current front and rear downforce difference according to the target front and rear downforce difference to control the vehicle to steer includes: If the vehicle's yaw rate is less than the preset steering target range, a front and rear downforce adjustment request is issued; increasing the current front and rear downforce difference to the target front and rear downforce difference within a preset time period according to the front and rear downforce adjustment request, and controlling the vehicle to turn; or If the vehicle's yaw rate is greater than the preset steering target range, a front and rear downforce adjustment request is issued; According to the front and rear downforce adjustment request, the current front and rear downforce difference is reduced to the target front and rear downforce difference within a preset time period, and the vehicle is controlled to turn.

5. The method according to claim 2, characterized in that Before correcting the current front and rear downforce difference according to the target front and rear downforce difference and controlling the vehicle to turn, the method further includes: If a gear change is detected or the accelerator pedal opening exceeds the preset steering range or the steering wheel angle returns to zero, an interrupt request is issued; According to the interrupt request, the front and rear downforce difference is controlled to be restored to the current front and rear downforce difference.

6. A vehicle steering control device, characterized in that: The device comprises: a parameter acquisition module, configured to acquire driving parameters of the vehicle when detecting that the steering wheel angle of the vehicle exceeds a preset angle, and determine whether the driving parameters meet a preset steering condition; a difference determination module, configured to determine a target front and rear downforce difference value based on a pre-stored correspondence between the driving parameters and the front and rear downforce difference value requests; The steering control module is used to correct the current front and rear downforce difference according to the target front and rear downforce difference and control the vehicle to steer.

7. The vehicle steering control device according to claim 6, characterized in that: The parameter acquisition module includes: a parameter acquisition submodule, configured to acquire driving parameters of the vehicle when detecting that the steering wheel angle of the vehicle exceeds a preset angle, wherein the driving parameters include a brake signal, a gear position, a vehicle speed, a yaw angular velocity, and an accelerator pedal opening; The judgment submodule is configured to judge whether the vehicle speed, the yaw rate and the accelerator pedal opening are within a preset steering range respectively if the braking signal and the gear change are not detected.

8. The vehicle steering control device according to claim 7, characterized in that: The difference determination module includes: a query submodule, configured to query a pre-stored calibration map table if the vehicle speed and accelerator pedal opening are within a preset steering range and the yaw rate is inconsistent with a preset steering target range; wherein the calibration map table stores a correspondence between the steering wheel angle, the yaw rate, and the front and rear downforce difference; The determination submodule is configured to determine a corresponding target front and rear downforce difference in the calibration map according to the steering wheel angle and the yaw angular velocity.

9. The vehicle steering control device according to claim 8, characterized in that: The control steering module includes: a first request submodule, configured to issue a front and rear downforce adjustment request if the vehicle's yaw rate is less than a preset steering target range; a first control submodule, configured to increase the current front and rear downforce difference to the target front and rear downforce difference within a preset time period according to the front and rear downforce adjustment request, and control the vehicle to turn; or a second request submodule, configured to issue a front and rear downforce adjustment request if the vehicle's yaw rate is greater than a preset steering target range; The second control submodule is configured to reduce the current front and rear downforce difference to the target front and rear downforce difference within a preset time period according to the front and rear downforce adjustment request, thereby controlling the vehicle to turn.

10. A vehicle, characterized in that: The vehicle steering control device comprises the vehicle steering control device as claimed in any one of claims 6 to 9.

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