Vehicle steering control method, device, and storage medium

Abstract

The application provides a vehicle steering control method, device and storage medium. The method corrects a target slip rate in response to detection of insufficient steering or excessive steering of the vehicle, and controls the vehicle according to the corrected target slip rate, so as to improve the lateral force of the tire, so that the lateral force of the tire generates a yaw moment for correcting the attitude of the vehicle body, and facilitates the recovery of the stability of the vehicle, and then in response to detection of the insufficient steering or the excessive steering of the vehicle, and the target slip rate is corrected to a preset slip rate threshold, a tire correction angle is determined, and the front wheel angle and the rear wheel angle are controlled, so as to reduce the lateral force required for completing the curve, and the insufficient steering or the excessive steering of the vehicle is solved. The method can reduce the degree of reduction of the slip rate caused by the curve, can improve the stability improvement effect of the vehicle, and can make the vehicle stable in the curve and obtain better acceleration performance.

Description

Technical Field

[0001] This application relates to the field of vehicle control technology, specifically to a vehicle steering control method, device, and storage medium. Background Technology

[0002] In the development of automotive technology, understeer and oversteer are common problems, especially during high-speed driving or sharp turns. Understeer or oversteer refers to a situation where, when a vehicle is turning, insufficient traction of the front or rear wheels prevents it from providing enough steering force, causing the vehicle to deviate from the driver's intended path and potentially leading to traffic accidents.

[0003] In recent years, with the continuous development of vehicle control systems, TCS (Traction Control System) has become one of the important safety assistance systems in modern automobiles. By monitoring information such as wheel speed and lateral acceleration, TCS automatically reduces engine output power or brakes the wheels when it detects wheel slippage, in order to prevent wheel slippage and ensure vehicle traction and driving stability.

[0004] However, the TCS system mainly acts on the drive wheels. In steering, it generally further reduces the wheel slip ratio, that is, further reduces the driving torque or applies braking torque. This results in a decrease in vehicle power and a decrease in vehicle speed when cornering. Summary of the Invention

[0005] In view of the above-mentioned defects or deficiencies in the prior art, this application aims to provide a vehicle steering control method, device and storage medium to solve the problem of vehicle speed reduction caused by vehicle cornering in the related art, and to ensure vehicle power performance.

[0006] This application provides a vehicle steering control method, the method comprising:

[0007] In response to the detection of understeering or oversteering of the vehicle, the target slip ratio of the vehicle is corrected, and the vehicle is controlled according to the corrected target slip ratio;

[0008] In response to the detection that the vehicle still has understeer or oversteer, and the target slip ratio is corrected to a preset slip ratio threshold, the tire correction angle of the vehicle is determined, and the front wheel steering angle and rear wheel steering angle of the vehicle are controlled according to the tire correction angle;

[0009] The preset slip ratio threshold is a pre-set minimum target slip ratio for the slip ratio correction stage, used to avoid excessive speed reduction due to excessive correction during the slip ratio correction stage.

[0010] Optionally, the method further includes:

[0011] The vehicle's driving information is obtained, and the saturation values ​​of the front and rear wheel lateral forces of the vehicle are determined based on the driving information.

[0012] Based on the saturation values ​​of the front wheel lateral force and the rear wheel lateral force, it is determined whether the vehicle has understeer or oversteer.

[0013] The front wheel lateral force saturation value describes the degree of saturation of the front wheel lateral force in the vehicle, and the rear wheel lateral force saturation value describes the degree of saturation of the rear wheel lateral force in the vehicle.

[0014] Optionally, the driving information includes vehicle speed, front axle steering angle, vehicle yaw rate, vehicle body slip angle, front axle center of gravity distance, rear axle steering angle and rear axle center of gravity distance. Determining the front wheel lateral force saturation value and rear wheel lateral force saturation value based on the driving information includes:

[0015] The front axle sideslip angle of the vehicle is determined based on the vehicle speed, the front axle steering angle, the front axle center of gravity distance, the vehicle yaw rate, and the vehicle body sideslip angle.

[0016] The rear axle sideslip angle of the vehicle is determined based on the vehicle speed, the rear axle steering angle, the rear axle center of gravity distance, the vehicle yaw rate, and the vehicle body sideslip angle.

[0017] The saturation value of the front wheel lateral force of the vehicle is determined based on the front axle sideslip angle, and the saturation value of the rear wheel lateral force of the vehicle is determined based on the rear axle sideslip angle.

[0018] Optionally, determining the saturation value of the front wheel lateral force of the vehicle based on the front axle slip angle includes:

[0019] In response to the front axle sideslip angle not exceeding a preset first sideslip angle, a preset saturation value is determined as the saturation value of the front wheel lateral force of the vehicle;

[0020] In response to the front axle sideslip angle being greater than the preset first sideslip angle, and the front axle sideslip angle not exceeding the preset second sideslip angle, the saturation value of the front wheel lateral force of the vehicle is determined based on the front axle sideslip angle, the preset first sideslip angle, and the preset second sideslip angle.

[0021] In response to the front axle sideslip angle being greater than the preset second sideslip angle, the saturation value of the front wheel lateral force of the vehicle is determined based on the front axle sideslip angle and the preset second sideslip angle.

[0022] Wherein, the preset second slip angle is greater than the preset first slip angle, the preset first slip angle is the maximum slip angle in the linear region of the vehicle's lateral force, and the preset second slip angle is the slip angle corresponding to the maximum lateral force of the vehicle.

[0023] Optionally, based on the front wheel lateral force saturation value and the rear wheel lateral force saturation value, determining whether the vehicle has understeer or oversteer includes:

[0024] The front wheel lateral force of the vehicle is determined to be saturated based on the front wheel lateral force saturation value, and the rear wheel lateral force of the vehicle is determined to be saturated based on the rear wheel lateral force saturation value.

[0025] In response to the saturation of the rear wheel lateral forces of the vehicle, it is determined that the vehicle is oversteer;

[0026] In response to the fact that the rear wheel lateral force of the vehicle is unsaturated and the front wheel lateral force of the vehicle is saturated, it is determined that the vehicle has understeer.

[0027] Optionally, correcting the target slip ratio of the vehicle includes:

[0028] For the saturation values ​​of the front wheel lateral force and the rear wheel lateral force, the saturation values ​​of the lateral force that are greater than the preset saturation state value are determined as saturation input indicators;

[0029] Based on the difference between the saturation input index and the preset saturation state value, the target slip ratio of the vehicle is corrected to reduce the difference between the saturation input index and the preset saturation state value by reducing the target slip ratio.

[0030] Optionally, determining the tire correction angle of the vehicle includes:

[0031] For the saturation values ​​of the front wheel lateral force and the rear wheel lateral force, the saturation values ​​of the lateral force that are greater than the preset saturation state value are determined as saturation input indicators;

[0032] The tire correction angle of the vehicle is determined based on the difference between the saturation input index and the preset saturation state value, so as to reduce the difference between the saturation input index and the preset saturation state value by means of the tire correction angle.

[0033] Optionally, controlling the front and rear wheel steering angles of the vehicle based on the tire-corrected steering angle includes:

[0034] The tire correction angle is distributed to the front and rear wheels of the vehicle according to a preset ratio to obtain the front wheel correction angle and the rear wheel correction angle;

[0035] If the vehicle is understeer, the front and rear wheels are controlled to rotate in opposite directions according to the front wheel correction angle and the rear wheel correction angle, respectively. If the vehicle is oversteer, the front and rear wheels are controlled to rotate in the same direction according to the front wheel correction angle and the rear wheel correction angle, respectively.

[0036] This application embodiment also provides an electronic device, the electronic device comprising:

[0037] Processor and memory;

[0038] The processor executes the steps of the vehicle steering control method provided in any embodiment of this application by calling the program or instructions stored in the memory.

[0039] This application also provides a computer-readable storage medium storing a program or instructions that cause a computer to perform the steps of the vehicle steering control method provided in any embodiment of this application.

[0040] In summary, this application proposes a vehicle steering control method. In response to the detection of understeer or oversteer, the method corrects the vehicle's target slip ratio and controls the vehicle according to the corrected target slip ratio. This releases the longitudinal force of the vehicle tires and increases the lateral force of the tires, causing the lateral force of the tires to generate a yaw moment to correct the vehicle's posture, facilitating the restoration of vehicle stability and solving the problem of understeer or oversteer. After correcting the target slip ratio, in response to the detection that understeer or oversteer still exists, and the target slip ratio is corrected to a preset slip ratio threshold, the vehicle's tire correction angle is determined. The front and rear wheel steering angles are controlled based on the tire correction angle to correct the vehicle's tire steering angle after correcting the target slip ratio. This reduces the lateral force required to complete cornering, further correcting the vehicle's posture and achieving stable vehicle control. Compared to related technologies that only reduce wheel slip ratio to maintain vehicle stability, this method first corrects the target slip ratio to a preset slip ratio threshold before correcting the vehicle's tire angle. This reduces the degree of slip ratio reduction caused by cornering, ensuring vehicle power. Furthermore, combining target slip ratio correction with tire angle correction improves vehicle stability. In addition, first correcting the target slip ratio to the preset slip ratio threshold allows for smooth tire adjustment to maintain tire grip, providing a basis for rear-wheel steering intervention. This ensures the smoothness of the angle correction process, allowing for tire angle correction even when the vehicle is still out of steering control. By adjusting the tire angle, the lateral force required to complete cornering is reduced, enabling the vehicle to maintain stability and achieve better acceleration performance in corners. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0042] Figure 1 This is a flowchart of a vehicle steering control method provided in an embodiment of this application;

[0043] Figure 2 This is a schematic diagram of a preset first side deflection angle and a preset second side deflection angle provided in an embodiment of this application;

[0044] Figure 3 This is a schematic diagram of a lateral force saturation value provided in an embodiment of this application;

[0045] Figure 4 This is a schematic diagram illustrating the detection of understeering and oversteering provided in an embodiment of this application;

[0046] Figure 5 This is a diagram illustrating a correction process provided in an embodiment of this application;

[0047] Figure 6 This is a system framework diagram provided in an embodiment of this application;

[0048] Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0049] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0050] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0051] As mentioned in the background section, this application proposes a vehicle steering control method to address the problems in the prior art. Figure 1 This is a flowchart of a vehicle steering control method provided in an embodiment of this application. See also... Figure 1 The vehicle steering control method specifically includes:

[0052] S110. In response to detecting understeering or oversteering of the vehicle, the vehicle's target slip ratio is corrected, and the vehicle is controlled according to the corrected target slip ratio.

[0053] Understeer occurs when, at a fixed steering wheel angle, the vehicle's actual turning radius is greater than the expected turning radius. This is caused by the front wheels reaching their traction limit before the rear wheels, thus losing their ability to provide lateral force. Oversteer occurs when, at a fixed steering wheel angle, the vehicle's actual turning radius is less than the expected turning radius. This is also caused by the rear wheels reaching their traction limit before the front wheels, thus losing their ability to provide lateral force.

[0054] Specifically, data collected by sensors in the vehicle, such as steering wheel angle sensor, yaw rate sensor, lateral acceleration sensor, and wheel speed sensor, can be acquired. The measured vehicle speed and measured steering wheel angle are then substituted into a pre-built vehicle motion model to predict the expected yaw rate and lateral acceleration of the vehicle at that speed and steering wheel angle, thus obtaining the expected yaw rate and expected lateral acceleration. The expected yaw rate is then compared with the measured yaw rate, and the expected lateral acceleration is compared with the measured lateral acceleration to detect whether the vehicle is understeering or oversteering.

[0055] For example, if the measured yaw rate is less than the expected yaw rate, the vehicle is determined to be understeer; if the measured yaw rate is greater than the expected yaw rate, the vehicle is determined to be oversteer.

[0056] In this embodiment of the application, the lateral forces of the front and rear wheels of the vehicle can be evaluated based on the vehicle's driving information used to describe the overall vehicle status. Then, the lateral forces of the front and rear wheels can be used to detect whether the vehicle is understeering or oversteering.

[0057] In one specific implementation, the method provided in this application further includes the following steps:

[0058] Step 11: Obtain the vehicle's driving information and determine the saturation values ​​of the front and rear wheel lateral forces based on the driving information.

[0059] Step 12: Based on the saturation values ​​of the front wheel lateral force and the rear wheel lateral force, determine whether the vehicle has understeer or oversteer.

[0060] Among them, driving information can be used to describe the overall vehicle status. Driving information can include data collected by various sensors in the vehicle, such as vehicle speed, vehicle yaw rate, body slip angle, front axle steering angle, and rear axle steering angle.

[0061] In step 11, the lateral force saturation of the front wheels of the vehicle can be evaluated based on the driving information, i.e., whether the front wheels can provide greater lateral force (lateral force saturation of the front wheels means that the front wheels cannot provide more lateral force), and the lateral force saturation value of the front wheels can be obtained. Similarly, the lateral force saturation of the rear wheels of the vehicle can be evaluated based on the driving information, i.e., whether the rear wheels can provide greater lateral force (lateral force saturation of the rear wheels means that the rear wheels cannot provide more lateral force), and the lateral force saturation value of the rear wheels can be obtained.

[0062] Among them, the front wheel lateral force saturation value is used to describe the degree of saturation of the front wheel lateral force in the vehicle, and the rear wheel lateral force saturation value describes the degree of saturation of the rear wheel lateral force in the vehicle.

[0063] Specifically, the front axle slip angle and rear axle slip angle of the vehicle can be determined through driving information, and the saturation values ​​of the front wheel lateral force and rear wheel lateral force can be determined respectively through the front axle slip angle and rear axle slip angle. Among them, the front axle slip angle is the slip angle at the front axle of the vehicle, and the rear axle slip angle is the slip angle at the rear axle of the vehicle.

[0064] Regarding step 11 above, in some embodiments, the driving information includes vehicle speed, front axle steering angle, vehicle yaw rate, vehicle body slip angle, front axle center of gravity distance, rear axle steering angle, and rear axle center of gravity distance. Determining the saturation values ​​of the front and rear wheel lateral forces based on the driving information includes the following steps:

[0065] Step 111: Determine the front axle slip angle of the vehicle based on the vehicle speed, front axle steering angle, front axle center of gravity distance, vehicle yaw rate, and vehicle body slip angle.

[0066] Step 112: Determine the rear axle slip angle of the vehicle based on the vehicle speed, rear axle steering angle, rear axle center of gravity distance, vehicle yaw rate, and vehicle body slip angle.

[0067] Step 113: Determine the saturation value of the front wheel lateral force of the vehicle based on the front axle slip angle, and determine the saturation value of the rear wheel lateral force of the vehicle based on the rear axle slip angle.

[0068] The front axle center of gravity distance can be the distance between the front axle and the center of gravity of the vehicle, while the rear axle center of gravity distance can be the distance between the rear axle and the center of gravity of the vehicle.

[0069] Specifically, in step 111, the vehicle speed, front axle steering angle, front axle center of gravity distance, vehicle yaw rate, and vehicle body slip angle can be substituted into a pre-built front wheel slip angle model (mathematical model) to obtain the vehicle's front axle slip angle. For example, the formula for the front wheel slip angle model is as follows:

[0070] ;

[0071] In the formula, Front axle side slip angle, This is the front axle steering angle. For vehicle body side slip angle, This is the distance between the front axle's center of gravity. For vehicle speed, This refers to the vehicle yaw rate.

[0072] In this embodiment, considering the sign (representing direction) of the vehicle yaw rate and vehicle slip angle, if the signs of the vehicle yaw rate and vehicle slip angle are the same, the calculated front axle slip angle will be lower than the actual slip angle, i.e., the calculated result will be too small. This will lead to an incorrect assessment of whether the front wheel lateral force is saturated, affecting the degree of subsequent yaw dynamic control intervention. Therefore, the above-mentioned front wheel slip angle model can be modified to handle two cases: the vehicle yaw rate and the vehicle slip angle having the same sign and different signs, thus avoiding errors in the front wheel slip angle caused by using the same formula. The modified front wheel slip angle model satisfies the following formula:

[0073] ;

[0074] In the formula, The symbol for vehicle yaw rate indicates the direction of the yaw rate. The symbol for the vehicle's side slip angle indicates the direction of the slip angle.

[0075] Specifically, in step 112, the vehicle speed, rear axle steering angle, rear axle center of gravity distance, vehicle yaw rate, and vehicle body slip angle can be substituted into a pre-built rear wheel slip angle model (mathematical model) to obtain the vehicle's rear axle slip angle. For example, the formula for the rear axle slip angle model is as follows:

[0076] ;

[0077] In the formula, Rear axle slip angle, Rear axle steering angle For vehicle body side slip angle, This is the distance between the rear axle's center of mass. For vehicle speed, This refers to the vehicle yaw rate.

[0078] After calculating the front axle sideslip angle and the rear axle sideslip angle, in step 113, the lateral force of the front wheels can be assessed by the front axle sideslip angle to determine whether the lateral force of the front wheels is saturated, and the lateral force of the rear wheels can be assessed by the rear axle sideslip angle to determine whether the lateral force of the rear wheels is saturated.

[0079] Regarding step 113 above, in one example, determining the saturation value of the front wheel lateral force of the vehicle based on the front axle slip angle includes:

[0080] In response to the front axle sideslip angle not exceeding a preset first sideslip angle, the preset saturation value is determined as the saturation value of the front wheel lateral force of the vehicle;

[0081] In response to the front axle sideslip angle being greater than a preset first sideslip angle and the front axle sideslip angle not exceeding a preset second sideslip angle, the saturation value of the front wheel lateral force of the vehicle is determined based on the front axle sideslip angle, the preset first sideslip angle, and the preset second sideslip angle.

[0082] In response to the front axle sideslip angle being greater than a preset second sideslip angle, the saturation value of the front wheel lateral force of the vehicle is determined based on the front axle sideslip angle and the preset second sideslip angle.

[0083] The preset second slip angle is greater than the preset first slip angle. The preset first slip angle is the maximum slip angle in the linear region of the vehicle's lateral force, and the preset second slip angle is the slip angle corresponding to the maximum lateral force of the vehicle.

[0084] In this embodiment, the linear lateral force region can refer to the area where the lateral force increases linearly with the increase of the road surface friction coefficient. The maximum lateral force can be the maximum lateral force that the tire can provide under different road surface friction coefficients. For example, the linear lateral force region of the front axle can be pre-calibrated according to tire parameters, and the maximum slip angle therein can be used as a preset first slip angle. Furthermore, the maximum lateral force of the front axle can be pre-calibrated according to tire parameters, and the corresponding slip angle can be used as a preset second slip angle.

[0085] For example, Figure 2 This is a schematic diagram of a preset first side deflection angle and a preset second side deflection angle provided in an embodiment of this application, as shown below. Figure 2 As shown, the horizontal axis represents the sideslip angle. The vertical axis represents the road surface friction coefficient. , To preset the first side deflection angle, This is a preset second side deflection angle. As can be seen from the diagram, in... Located in [0 Within this interval, there is a linear increasing relationship between the road surface friction coefficient and the sideslip angle; this region can be understood as the linear region of lateral force. lie in[ Within the specified range, there is a slowly increasing relationship between the road surface friction coefficient and the sideslip angle; the sideslip angle increases slowly as the road surface friction coefficient increases. The corresponding road surface friction coefficient is , and when At that time, the road surface friction coefficient no longer increases, therefore This is the sideslip angle corresponding to the maximum lateral force.

[0086] Specifically, if the front axle sideslip angle does not exceed the preset first sideslip angle, it indicates that the front axle lateral force is completely unsaturated, and the front wheels can still provide sufficient lateral force. In this case, the preset saturation value can be determined as the saturation value of the vehicle's front wheel lateral force. Here, the preset saturation value represents that the lateral force is completely unsaturated, such as 0.

[0087] If the front axle sideslip angle is greater than the preset first sideslip angle, and the front axle sideslip angle does not exceed the preset second sideslip angle, that is, the front axle sideslip angle is between the preset first sideslip angle and the preset second sideslip angle, it means that the front and rear lateral forces are not saturated, and the front wheels can still provide more lateral force. At this time, the saturation degree of the front wheel lateral force can be measured by the difference between the front axle sideslip angle and the preset first sideslip angle, and the difference between the preset first sideslip angle and the preset second sideslip angle, and the saturation value of the front wheel lateral force can be obtained.

[0088] If the front axle sideslip angle is greater than the preset second sideslip angle, the front wheel lateral force saturation value of the vehicle is determined to be saturated based on the front axle sideslip angle and the preset second sideslip angle. The front wheels cannot provide more lateral force. At this time, the saturation degree of the front wheel lateral force can be measured by the ratio between the front axle sideslip angle and the preset second sideslip angle, and the front wheel lateral force saturation value can be obtained.

[0089] It should be noted that if the calculation of the front axle slip angle has a sign, then the above comparison of the front axle slip angle with the preset first slip angle and the preset second slip angle refers to comparing the absolute value of the front axle slip angle with the preset first slip angle and the preset second slip angle. Furthermore, the front axle slip angle used in the subsequent calculation of the front wheel lateral force saturation value is also an absolute value.

[0090] For example, the saturation value of the front wheel lateral force can be determined by the following formula:

[0091] ;

[0092] In the formula, This represents the preset first side deflection angle. This represents the preset second side deflection angle. This is the absolute value of the front axle side slip angle. This represents the saturation value of the lateral force on the front wheel.

[0093] Figure 3 This is a schematic diagram of a lateral force saturation value provided in an embodiment of this application, such as... Figure 3 As shown, the horizontal axis represents the sideslip angle. The vertical axis represents the saturation value of the lateral force. , To preset the first side deflection angle, This is a preset second side deflection angle. As can be seen from the diagram, in... Located in [0 When within the interval, =0, in lie in[ When within the interval, along with It increases with the increase of, and the maximum value is 1, while when hour, along with It increases with the increase of.

[0094] By comparing the front axle slip angle with the maximum slip angle and the slip angle corresponding to the maximum lateral force in the linear lateral force region, it is possible to accurately determine whether the front wheel lateral force is saturated. Furthermore, based on the front axle slip angle, the maximum slip angle and the slip angle corresponding to the maximum lateral force in the linear lateral force region, it is possible to accurately measure the degree of saturation of the front wheel lateral force, which facilitates subsequent target slip ratio correction and steering angle correction based on this, further ensuring vehicle driving stability.

[0095] In this embodiment of the application, the calculation of the saturation value of the rear wheel lateral force can refer to the above-described calculation process of the saturation value of the front wheel lateral force.

[0096] Specifically, in response to the rear axle sideslip angle not exceeding a preset third sideslip angle, a preset saturation value is determined as the saturation value of the vehicle's rear wheel lateral force. In response to the rear axle sideslip angle being greater than the preset third sideslip angle, and the rear axle sideslip angle not exceeding a preset fourth sideslip angle, the saturation value of the vehicle's rear wheel lateral force is determined based on the rear axle sideslip angle, the preset third sideslip angle, and the preset fourth sideslip angle. In response to the rear axle sideslip angle being greater than the preset fourth sideslip angle, the saturation value of the vehicle's rear wheel lateral force is determined based on the rear axle sideslip angle and the preset fourth sideslip angle. The preset fourth sideslip angle is greater than the preset third sideslip angle, where the preset third sideslip angle is the maximum sideslip angle in the linear region of the vehicle's rear axle lateral force, and the preset fourth sideslip angle is the sideslip angle corresponding to the maximum lateral force of the vehicle's rear axle.

[0097] For example, the calculation of the saturation value of the rear wheel lateral force is as follows:

[0098] ;

[0099] In the formula, This represents the preset third side deflection angle. This represents the preset fourth side deflection angle. This is the absolute value of the rear axle side slip angle. This represents the saturation value of the lateral force on the rear wheel.

[0100] This application embodiment calculates the front axle sideslip angle and the rear axle sideslip angle of the vehicle, and then evaluates the lateral force saturation of the front and rear wheels respectively through the front axle sideslip angle and the rear axle sideslip angle, which can achieve accurate detection of understeer and oversteer of the vehicle, thereby ensuring the driving stability of the vehicle.

[0101] After obtaining the saturation values ​​of the front wheel lateral force and the rear wheel lateral force, in step 12, it is further possible to determine whether there is understeer or oversteer by using the saturation values ​​of the front wheel lateral force and the rear wheel lateral force.

[0102] Regarding step 12 above, in some implementations, based on the saturation values ​​of the front and rear wheel lateral forces, it is determined whether the vehicle has understeer or oversteer, including:

[0103] The saturation value of the front wheel lateral force is used to determine whether the saturation of the vehicle's front wheel lateral force is saturated, and the saturation value of the rear wheel lateral force is used to determine whether the saturation of the vehicle's rear wheel lateral force is saturated.

[0104] In response to the saturation of the lateral forces on the rear wheels of the vehicle, it is determined that the vehicle is oversteer;

[0105] In response to the unsaturated lateral force of the vehicle's rear wheels and the saturated lateral force of the vehicle's front wheels, it is determined that the vehicle has understeer.

[0106] Specifically, the saturation value of the front wheel lateral force can be compared with the preset saturation value, and the saturation value of the rear wheel lateral force can also be compared with the preset saturation value. The preset saturation value describes the saturation of the tire lateral force, such as 1.

[0107] Specifically, if the saturation value of the front wheel lateral force is greater than the preset saturation value, it indicates that the front wheel lateral force is saturated; if the saturation value of the rear wheel lateral force is greater than the preset saturation value, it indicates that the rear wheel lateral force is saturated.

[0108] Furthermore, if the rear wheel lateral force is saturated and the front wheel lateral force is saturated, it can be determined that the vehicle is oversteer; if the rear wheel lateral force is saturated and the front wheel lateral force is not saturated, it can be determined that the vehicle is oversteer; if the rear wheel lateral force is not saturated and the front wheel lateral force is saturated, it can be determined that the vehicle is understeer; if the rear wheel lateral force is not saturated and the front wheel lateral force is not saturated, it can be determined that the vehicle is in steady-state driving.

[0109] For example, Figure 4 This is a schematic diagram illustrating the detection of understeering and oversteering provided in an embodiment of this application, as shown below. Figure 4 As shown, the horizontal axis represents the saturation value of the front wheel lateral force. The vertical axis represents the saturation value of the rear wheel lateral force. As can be seen from the figure, and All values ​​of 1 represent the physical limit of driving speed. and When all values ​​are less than 1 (the preset saturation value), the vehicle is stable. When the value is greater than 1, the vehicle oversteers. Less than 1 and When the value is greater than 1, the vehicle is not able to turn.

[0110] In the above implementation, the saturation values ​​of the front and rear wheel lateral forces can be used to determine whether the lateral forces of the front and rear wheels are saturated. Furthermore, by combining the saturation values ​​of the front and rear wheel lateral forces, understeer and oversteer of the vehicle can be identified, enabling accurate detection of vehicle steering loss of control. This facilitates timely intervention in steering loss of control and ensures vehicle driving stability and safety.

[0111] After detecting whether the vehicle is understeer or oversteer, if understeer or oversteer is found, intervention can be made to address the loss of steering control. Specifically, the target slip ratio of the vehicle can be corrected first, i.e., the target slip ratio can be reduced. Subsequently, control can be performed according to the corrected target slip ratio to release the longitudinal force of the tires, allowing the tires to generate more lateral force to correct the vehicle's posture.

[0112] The target slip ratio is the desired slip ratio that the vehicle will achieve; the slip ratio is used to quantify the difference between the tire's rolling speed (i.e., wheel speed) and the vehicle speed.

[0113] It should be noted that the purpose of modifying the target slip ratio in this application embodiment is as follows: Considering that in the friction circle theory, the total adhesion force generated when a tire contacts the ground is a fixed value, this fixed value is spent in two directions: 1. longitudinal force (for acceleration or deceleration), 2. lateral force (for changing direction). The friction circle describes that the combination of these two forces cannot exceed a fixed value; the more longitudinal force, the less force is available for lateral movement. Therefore, by modifying the target slip ratio, the driving torque of the tire can be reduced, thereby reducing the longitudinal force of the tire, so that more force can be used for lateral movement (i.e., releasing the lateral force potential of the rear wheels, allowing the rear wheels to regain grip), thereby correcting the vehicle's cornering posture and resolving oversteer or understeer. Furthermore, by providing more lateral force, the effect of subsequent angle correction can be increased, providing a stronger basis for subsequent angle correction, thus making the entire intervention process smoother and more natural, achieving stable steering control.

[0114] In the embodiments of this application, the target slip ratio can be corrected based on the saturation level of the front wheel lateral force or the rear wheel lateral force. For example, the higher the saturation level of the front wheel lateral force or the rear wheel lateral force, the greater the correction to the target slip ratio, i.e., the smaller the target slip ratio.

[0115] In one specific implementation, correcting the target slip ratio of the vehicle includes the following steps:

[0116] Step 21: For the saturation values ​​of the front wheel lateral force and the rear wheel lateral force, the saturation value of the lateral force that is greater than the preset saturation state value is determined as the saturation input index;

[0117] Step 22: Based on the difference between the saturation input index and the preset saturation state value, adjust the vehicle's target slip ratio to reduce the difference between the saturation input index and the preset saturation state value by reducing the target slip ratio.

[0118] In step 21, the saturation value of the front wheel lateral force is compared with a preset saturation state value, and the saturation value of the rear wheel lateral force is also compared with the preset saturation state value. If the saturation value of the front wheel lateral force is greater than the preset saturation state value, then the saturation value of the front wheel lateral force is determined as the saturation input index; if the saturation value of the rear wheel lateral force is greater than the preset saturation state value, then the saturation value of the rear wheel lateral force is determined as the saturation input index.

[0119] Furthermore, in step 22, the difference between the saturation input index and the preset saturation state value can be calculated. This difference can be determined as understeer control deviation or oversteer control deviation (if the vehicle has understeer, the difference is the understeer control deviation; if the vehicle has oversteer, the difference is the oversteer control deviation). Then, the target slip ratio of the vehicle can be corrected based on the understeer control deviation or the oversteer control deviation.

[0120] After correcting the target slip ratio, control can be applied according to the target slip ratio to ensure that the vehicle's actual slip ratio reaches the target slip ratio. For example, the vehicle's actual slip ratio can be obtained, and the vehicle's drive torque can be determined based on the deviation between the target slip ratio and the actual slip ratio. The vehicle can then be controlled according to this drive torque, and the vehicle's actual slip ratio can be obtained again. This process is repeated until the actual slip ratio reaches the target slip ratio.

[0121] It should be noted that, in the embodiments of this application, the correction of the target slip ratio can be repeated, i.e., a dynamic optimization process, with iterative corrections continued based on the corrected results. Furthermore, the cutoff condition for correcting the target slip ratio can be that the vehicle does not experience steering loss of control or the target slip ratio reaches a preset slip ratio threshold.

[0122] For example, a feedback control algorithm (such as PI control) can be used to take the understeer control deviation or oversteer control deviation as input, correct the target slip ratio based on the understeer control deviation or oversteer control deviation, and control according to the corrected target slip ratio. Then, the understeer control deviation or oversteer control deviation is recalculated, and this is used as input to continue correcting the target slip ratio until the understeer control deviation or oversteer control deviation is 0, that is, the lateral forces of the front wheels and the rear wheels are both unsaturated, or the target slip ratio is corrected to 0.

[0123] Through the above implementation method, the difference between the preset saturation state value and the front wheel lateral force saturation value, or the difference between the rear wheel lateral force saturation value and the saturation input index, can be used as input to correct the target slip ratio. This allows the correction of the target slip ratio to reduce the tire lateral force saturation level as quickly as possible, thereby improving the efficiency of handling steering loss of control.

[0124] S120. In response to detecting that the vehicle still has understeer or oversteer, and the target slip ratio is corrected to a preset slip ratio threshold, the tire correction angle of the vehicle is determined, and the front wheel angle and rear wheel angle of the vehicle are controlled according to the tire correction angle.

[0125] Specifically, after correcting the target slip ratio, if it is detected that the vehicle does not have understeer or oversteer (which can be determined by recalculating the saturation values ​​of the front and rear wheel lateral forces), the correction can be stopped. If it is detected that the vehicle still has understeer and oversteer, the target slip ratio can be corrected until the target slip ratio reaches the preset slip ratio threshold.

[0126] The preset slip ratio threshold can be a pre-set minimum target slip ratio for the slip ratio correction stage, used to avoid excessive speed reduction due to excessive correction during the slip ratio correction stage. For example, the preset slip ratio threshold can be 0.

[0127] The purpose of setting a preset slip ratio threshold is to limit the target slip ratio during the slip ratio correction stage, thereby preventing excessive target slip ratio correction that could lead to excessive speed reduction during the slip ratio correction stage and ensuring vehicle power.

[0128] In this embodiment of the application, if the vehicle still has understeer or oversteer after the target slip ratio is corrected to the preset slip ratio threshold, then tire angle correction can be performed to reduce the lateral force burden required to complete the cornering by adjusting the tire angle, so that the vehicle can remain stable in the corner.

[0129] In the embodiments of this application, the tire steering angle can be corrected based on the saturation level of the front wheel lateral force or the rear wheel lateral force. For example, the higher the saturation level of the front wheel lateral force or the rear wheel lateral force, the greater the correction to the tire steering angle, i.e., the larger the tire steering angle.

[0130] In one specific implementation, determining the tire correction angle of the vehicle includes the following steps:

[0131] Step 31: For the saturation values ​​of the front wheel lateral force and the rear wheel lateral force, the saturation values ​​of the lateral force that are greater than the preset saturation state value are determined as the saturation input index;

[0132] Step 32: Determine the vehicle's tire correction angle based on the difference between the saturation input index and the preset saturation state value, so as to reduce the difference between the saturation input index and the preset saturation state value by adjusting the tire correction angle.

[0133] In step 31, the saturation value of the front wheel lateral force can be compared with a preset saturation state value, and the saturation value of the rear wheel lateral force can also be compared with a preset saturation state value. If the saturation value of the front wheel lateral force is greater than the preset saturation state value, then the saturation value of the front wheel lateral force is determined as the saturation input index; if the saturation value of the rear wheel lateral force is greater than the preset saturation state value, then the saturation value of the rear wheel lateral force is determined as the saturation input index.

[0134] Furthermore, in step 32, the difference between the saturation input index and the preset saturation state value can be calculated. This difference can be determined as understeer control deviation or oversteer control deviation (if the vehicle has understeer, the difference is the understeer control deviation; if the vehicle has oversteer, the difference is the oversteer control deviation). Then, the tire correction angle of the vehicle can be determined based on the understeer control deviation or the oversteer control deviation.

[0135] The tire-corrected steering angle can be considered as the total additional steering angle added to the original tire steering angle. It's an overall additional steering angle correction value, not the angle the driver directly turns the steering wheel, but rather an extra steering angle added by the system for stability. The steering angle can be understood as the angle between the tire's orientation and the vehicle's direction, specifically the angle between the tire's center plane and the vehicle's longitudinal axis. This tire-corrected steering angle includes both front-wheel and rear-wheel corrected steering angles.

[0136] After determining the corrected tire steering angle, the front and rear wheel steering angles of the vehicle can be controlled according to the corrected tire steering angle to correct the tire steering angle. It should be noted that, in the embodiments of this application, the correction of the tire steering angle can be repeated, that is, a dynamic optimization process, and iterative correction can be performed based on the corrected results.

[0137] For example, a feedback control algorithm (such as PI control) can be used to take the understeer control deviation or oversteer control deviation as input, determine the tire correction angle based on the understeer control deviation or oversteer control deviation, and control the front wheel and rear wheel steering angles according to the tire correction angle. After that, the understeer control deviation or oversteer control deviation is recalculated, and then the tire correction angle is determined again based on this, until the understeer control deviation or oversteer control deviation is 0, that is, the lateral forces of the front wheels and the rear wheels are both unsaturated.

[0138] The PI controller can learn the mapping relationship between steering control deviation (understeer control deviation or oversteer control deviation) and tire correction angle in advance through data. After the understeer control deviation or oversteer control deviation is input into the PI controller, the PI controller can calculate the tire correction angle according to the mapping relationship and output it.

[0139] Through the above implementation method, the difference between the preset saturation state value and the front wheel lateral force saturation value, or the difference between the rear wheel lateral force saturation value and the saturation input index, can be used as input to correct the tire steering angle, thereby achieving the goal of reducing the tire lateral force saturation level as quickly as possible. While ensuring the efficiency of handling steering loss of control, it can also ensure the rapid stabilization of the vehicle body.

[0140] In this embodiment of the application, after determining the tire correction angle, it can be allocated to the front and rear wheels in a certain proportion, thereby achieving the correction of the front wheel steering angle to the rear wheel steering angle.

[0141] In one specific implementation, controlling the front wheel steering angle and rear wheel steering angle of a vehicle based on tire-corrected steering angle includes the following steps:

[0142] Step 41: Distribute the tire correction angle to the front and rear wheels of the vehicle according to a preset ratio to obtain the front wheel correction angle and the rear wheel correction angle;

[0143] Step 42: If the vehicle is understeer, control the front and rear wheels to turn in opposite directions according to the front wheel correction angle and the rear wheel correction angle respectively. If the vehicle is oversteer, control the front and rear wheels to turn in the same direction according to the front wheel correction angle and the rear wheel correction angle respectively.

[0144] The preset ratio can be a pre-calibrated front and rear axle steering angle distribution ratio. In step 41, the tire correction angle can be distributed to the front and rear wheels according to the preset ratio to obtain the front wheel correction angle and the rear wheel correction angle.

[0145] For example, tire correction angle can be used The front wheel correction angle and rear wheel correction angle can be calculated using the following formula:

[0146] ;

[0147] In the formula, This is the front wheel correction angle, which is an additional steering angle added to the original steering angle of the front wheels. The rear wheel steering correction angle is an additional steering angle added to the original steering angle of the rear wheels. This is a preset ratio.

[0148] For example, if the vehicle has understeer, the preset ratio can be 70% to increase the lateral force on the front wheels. If the vehicle has oversteer, the preset ratio can be 20% to increase the lateral force on the rear wheels.

[0149] Furthermore, in step 42, it is determined whether the vehicle is understeer or oversteer. If it is understeer, the front wheels are controlled to rotate according to the front wheel correction angle, and the rear wheels are controlled to rotate according to the rear wheel correction angle, with the front and rear wheels rotating in opposite directions to reduce the understeer tendency. If it is oversteer, the front wheels are controlled to rotate according to the front wheel correction angle, and the rear wheels are controlled to rotate according to the rear wheel correction angle, with the front and rear wheels rotating in the same direction to reduce the oversteer tendency.

[0150] Figure 5 This is a diagram illustrating a correction process provided in an embodiment of this application, such as... Figure 5 As shown, after detecting understeer or oversteer in the vehicle, the understeer control deviation or oversteer control deviation can be determined. If the understeer control deviation or oversteer control deviation is greater than 0, the target slip ratio is further corrected and control is performed according to the target slip ratio. If the understeer control deviation or oversteer control deviation is less than 0, the target slip ratio is not corrected.

[0151] After correcting the target slip ratio, the understeer control deviation or oversteer control deviation can be recalculated. If the understeer control deviation or oversteer control deviation is greater than 0, and the target slip ratio is corrected to the preset slip ratio threshold, it means that the vehicle still has understeer or oversteer, and the target slip ratio correction has reached its limit. At this time, the tire angle can be corrected, that is, the tire correction angle is calculated and the tire correction angle is allocated to the front and rear wheels to perform front wheel angle correction and rear wheel angle correction.

[0152] If the understeer control deviation or oversteer control deviation is less than 0, the tire angle is not corrected. If the understeer control deviation or oversteer control deviation is greater than 0, and the target slip ratio is not corrected to the preset slip ratio threshold, the target slip ratio is corrected.

[0153] Through steps 41-42 above, the target slip ratio correction and tire angle correction can be combined. By correcting the tire angle, the reduction in the target slip ratio caused by cornering can be reduced, thereby improving the vehicle speed reduction caused by cornering and ensuring the vehicle's power. Furthermore, the tire angle correction can further stabilize the vehicle and ensure the vehicle's cornering stability.

[0154] The vehicle steering control method provided in this application embodiment, in response to detecting understeer or oversteer of the vehicle, corrects the target slip ratio of the vehicle and controls the vehicle according to the corrected target slip ratio to release the longitudinal force of the vehicle tires and increase the lateral force of the tires. This allows the lateral force of the tires to generate a yaw moment to correct the vehicle's posture, facilitating the restoration of vehicle stability and solving the problem of understeer or oversteer. After correcting the target slip ratio, in response to detecting that the vehicle still has understeer or oversteer, and the target slip ratio is corrected to a preset slip ratio threshold, the tire correction angle of the vehicle is determined, and the front wheel angle and rear wheel angle of the vehicle are controlled according to the tire correction angle. This corrects the vehicle's tire angle after correcting the target slip ratio, thereby increasing the lateral force of the tires and further correcting the vehicle's posture, achieving stable control of the vehicle. Compared to related technologies that only reduce wheel slip ratio to maintain vehicle stability, this method first corrects the target slip ratio to a preset slip ratio threshold before correcting the vehicle's tire angle. This reduces the degree of slip ratio reduction caused by cornering, ensuring vehicle power. Furthermore, combining target slip ratio correction with tire angle correction improves vehicle stability. In addition, first correcting the target slip ratio to the preset slip ratio threshold allows for smooth tire adjustment to maintain tire grip, providing a basis for rear-wheel steering intervention. This ensures the smoothness of the angle correction process, allowing for tire angle correction even when the vehicle is still out of control. By adjusting the tire angle, the lateral force required to complete cornering is reduced, enabling the vehicle to maintain stability and achieve better acceleration performance in corners.

[0155] The vehicle steering control method provided in this application embodiment can be executed by a vehicle steering control system, which may include a TCS (Traction Control System) controller and an RWS (Rear Wheel Steering) controller, wherein:

[0156] The TCS controller is used to correct the target slip ratio of the vehicle in response to the detection of understeering or oversteering, and to control the vehicle according to the corrected target slip ratio.

[0157] The RWS controller is configured to, in response to detecting that the vehicle still has understeer or oversteer, and the target slip ratio is corrected to a preset slip ratio threshold, determine the tire correction angle of the vehicle, and control the front wheel and rear wheel steering angles of the vehicle based on the tire correction angle.

[0158] Optionally, the TCS controller is also used for:

[0159] The vehicle's driving information is obtained, and the saturation values ​​of the front and rear wheel lateral forces of the vehicle are determined based on the driving information.

[0160] Based on the saturation values ​​of the front wheel lateral force and the rear wheel lateral force, it is determined whether the vehicle has understeer or oversteer.

[0161] The front wheel lateral force saturation value describes the degree of saturation of the front wheel lateral force in the vehicle, and the rear wheel lateral force saturation value describes the degree of saturation of the rear wheel lateral force in the vehicle.

[0162] Optionally, the driving information includes vehicle speed, front axle steering angle, vehicle yaw rate, body slip angle, front axle center of gravity distance, rear axle steering angle and rear axle center of gravity distance, and the TCS controller, specifically used for:

[0163] The front axle sideslip angle of the vehicle is determined based on the vehicle speed, the front axle steering angle, the front axle center of gravity distance, the vehicle yaw rate, and the vehicle body sideslip angle.

[0164] The rear axle sideslip angle of the vehicle is determined based on the vehicle speed, the rear axle steering angle, the rear axle center of gravity distance, the vehicle yaw rate, and the vehicle body sideslip angle.

[0165] The saturation value of the front wheel lateral force of the vehicle is determined based on the front axle sideslip angle, and the saturation value of the rear wheel lateral force of the vehicle is determined based on the rear axle sideslip angle.

[0166] Optional, TCS controller, specifically used for:

[0167] In response to the front axle sideslip angle not exceeding a preset first sideslip angle, a preset saturation value is determined as the saturation value of the front wheel lateral force of the vehicle;

[0168] In response to the front axle sideslip angle being greater than the preset first sideslip angle, and the front axle sideslip angle not exceeding the preset second sideslip angle, the saturation value of the front wheel lateral force of the vehicle is determined based on the front axle sideslip angle, the preset first sideslip angle, and the preset second sideslip angle.

[0169] In response to the front axle sideslip angle being greater than the preset second sideslip angle, the saturation value of the front wheel lateral force of the vehicle is determined based on the front axle sideslip angle and the preset second sideslip angle.

[0170] Wherein, the preset second slip angle is greater than the preset first slip angle, the preset first slip angle is the maximum slip angle in the linear region of the vehicle's lateral force, and the preset second slip angle is the slip angle corresponding to the maximum lateral force of the vehicle.

[0171] Optional, TCS controller, specifically used for:

[0172] The front wheel lateral force of the vehicle is determined to be saturated based on the front wheel lateral force saturation value, and the rear wheel lateral force of the vehicle is determined to be saturated based on the rear wheel lateral force saturation value.

[0173] In response to the saturation of the rear wheel lateral forces of the vehicle, it is determined that the vehicle is oversteer;

[0174] In response to the fact that the rear wheel lateral force of the vehicle is unsaturated and the front wheel lateral force of the vehicle is saturated, it is determined that the vehicle has understeer.

[0175] Optional, TCS controller, specifically used for:

[0176] For the saturation values ​​of the front wheel lateral force and the rear wheel lateral force, the saturation values ​​of the lateral force that are greater than the preset saturation state value are determined as saturation input indicators;

[0177] Based on the difference between the saturation input index and the preset saturation state value, the target slip ratio of the vehicle is corrected to reduce the difference between the saturation input index and the preset saturation state value by reducing the target slip ratio.

[0178] Optional, RWS controller, specifically used for:

[0179] For the saturation values ​​of the front wheel lateral force and the rear wheel lateral force, the saturation values ​​of the lateral force that are greater than the preset saturation state value are determined as saturation input indicators;

[0180] The tire correction angle of the vehicle is determined based on the difference between the saturation input index and the preset saturation state value, so as to reduce the difference between the saturation input index and the preset saturation state value by means of the tire correction angle.

[0181] Optional, RWS controller, specifically used for:

[0182] The tire correction angle is distributed to the front and rear wheels of the vehicle according to a preset ratio to obtain the front wheel correction angle and the rear wheel correction angle;

[0183] If the vehicle is understeer, the front and rear wheels are controlled to rotate in opposite directions according to the front wheel correction angle and the rear wheel correction angle, respectively. If the vehicle is oversteer, the front and rear wheels are controlled to rotate in the same direction according to the front wheel correction angle and the rear wheel correction angle, respectively.

[0184] Figure 6 This is a system framework diagram provided in an embodiment of this application, such as... Figure 6As shown, after acquiring driving information, the TCS controller can detect whether there is understeer or oversteer, and determine the understeer control deviation or oversteer control deviation. Then, the TCS controller uses the understeer control deviation or oversteer control deviation as input to correct the target slip ratio, and then performs braking torque control or drive torque control according to the corrected target slip ratio. If braking torque control is performed, the braking torque controller can send a braking torque request to the vehicle; if drive torque control is performed, the drive torque controller can send a drive torque request to the vehicle.

[0185] After correcting the target slip ratio to the preset slip ratio threshold, if understeer or oversteer still exists, the RWS controller takes the understeer control deviation or oversteer control deviation as input, outputs the tire correction angle, and then sends a steering angle request to the vehicle to correct the tire steering angle.

[0186] Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. For example... Figure 7 As shown, the electronic device 400 includes one or more processors 401 and memory 402.

[0187] The processor 401 may be a central processing unit (CPU) or other form of processing unit with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device 400 to perform desired functions.

[0188] The memory 402 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 401 may execute the program instructions to implement the vehicle steering control method of any embodiment of this application described above and / or other desired functions. Various contents such as initial extrinsic parameters and thresholds may also be stored in the computer-readable storage medium.

[0189] In one example, the electronic device 400 may further include an input device 403 and an output device 404, these components being interconnected via a bus system and / or other forms of connection mechanisms (not shown). The input device 403 may include, for example, a keyboard, a mouse, etc. The output device 404 may output various information to the outside, including warning messages, braking force, etc. The output device 404 may include, for example, a display, a speaker, a printer, and a communication network and its connected remote output devices, etc.

[0190] Of course, for the sake of simplicity, Figure 7 Only some of the components of the electronic device 400 relevant to this application are shown in this illustration; components such as buses, input / output interfaces, etc., are omitted. In addition, the electronic device 400 may include any other suitable components depending on the specific application.

[0191] In addition to the methods and devices described above, embodiments of this application may also be computer program products, which include computer program instructions that, when executed by a processor, cause the processor to perform the steps of the vehicle steering control method provided in any embodiment of this application.

[0192] The computer program product can be written in any combination of one or more programming languages ​​to perform the operations of the embodiments of this application. The programming languages ​​include object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0193] Furthermore, embodiments of this application may also be computer-readable storage media storing computer program instructions thereon, which, when executed by a processor, cause the processor to perform the steps of the vehicle steering control method provided in any embodiment of this application.

[0194] The computer-readable storage medium may be any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof.

[0195] It should be noted that the terminology used in this application is for the purpose of describing specific embodiments only and is not intended to limit the scope of this application. As shown in the specification and claims of this application, unless the context clearly indicates otherwise, words such as "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. The terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, or apparatus. Without further limitations, an element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes said element.

[0196] It should also be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," "linked," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0197] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. The above descriptions are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A vehicle steering control method, characterized in that, include: In response to the detection of understeering or oversteering of the vehicle, the target slip ratio of the vehicle is corrected, and the vehicle is controlled according to the corrected target slip ratio; In response to the detection that the vehicle still has understeer or oversteer, and the target slip ratio is corrected to a preset slip ratio threshold, the tire correction angle of the vehicle is determined, and the front wheel steering angle and rear wheel steering angle of the vehicle are controlled according to the tire correction angle; The preset slip ratio threshold is a pre-set minimum target slip ratio for the slip ratio correction stage, used to avoid excessive speed reduction due to excessive correction during the slip ratio correction stage.

2. The method according to claim 1, characterized in that, The method further includes: The vehicle's driving information is obtained, and the saturation values ​​of the front and rear wheel lateral forces of the vehicle are determined based on the driving information. Based on the saturation values ​​of the front wheel lateral force and the rear wheel lateral force, it is determined whether the vehicle has understeer or oversteer. The front wheel lateral force saturation value describes the degree of saturation of the front wheel lateral force in the vehicle, and the rear wheel lateral force saturation value describes the degree of saturation of the rear wheel lateral force in the vehicle.

3. The method according to claim 2, characterized in that, The driving information includes vehicle speed, front axle steering angle, vehicle yaw rate, vehicle body slip angle, front axle center of gravity distance, rear axle steering angle, and rear axle center of gravity distance. Based on this driving information, the saturation values ​​of the front and rear wheel lateral forces are determined, including: The front axle sideslip angle of the vehicle is determined based on the vehicle speed, the front axle steering angle, the front axle center of gravity distance, the vehicle yaw rate, and the vehicle body sideslip angle. The rear axle sideslip angle of the vehicle is determined based on the vehicle speed, the rear axle steering angle, the rear axle center of gravity distance, the vehicle yaw rate, and the vehicle body sideslip angle. The saturation value of the front wheel lateral force of the vehicle is determined based on the front axle sideslip angle, and the saturation value of the rear wheel lateral force of the vehicle is determined based on the rear axle sideslip angle.

4. The method according to claim 3, characterized in that, Determining the saturation value of the front wheel lateral force of the vehicle based on the front axle slip angle includes: In response to the front axle sideslip angle not exceeding a preset first sideslip angle, a preset saturation value is determined as the saturation value of the front wheel lateral force of the vehicle; In response to the front axle sideslip angle being greater than the preset first sideslip angle, and the front axle sideslip angle not exceeding the preset second sideslip angle, the saturation value of the front wheel lateral force of the vehicle is determined based on the front axle sideslip angle, the preset first sideslip angle, and the preset second sideslip angle. In response to the front axle sideslip angle being greater than the preset second sideslip angle, the saturation value of the front wheel lateral force of the vehicle is determined based on the front axle sideslip angle and the preset second sideslip angle. Wherein, the preset second slip angle is greater than the preset first slip angle, the preset first slip angle is the maximum slip angle in the linear region of the vehicle's lateral force, and the preset second slip angle is the slip angle corresponding to the maximum lateral force of the vehicle.

5. The method according to claim 2, characterized in that, Based on the front wheel lateral force saturation value and the rear wheel lateral force saturation value, determine whether the vehicle has understeer or oversteer, including: The front wheel lateral force of the vehicle is determined to be saturated based on the front wheel lateral force saturation value, and the rear wheel lateral force of the vehicle is determined to be saturated based on the rear wheel lateral force saturation value. In response to the saturation of the rear wheel lateral forces of the vehicle, it is determined that the vehicle is oversteer; In response to the fact that the rear wheel lateral force of the vehicle is unsaturated and the front wheel lateral force of the vehicle is saturated, it is determined that the vehicle has understeer.

6. The method according to claim 2, characterized in that, Correcting the target slip ratio of the vehicle includes: For the saturation values ​​of the front wheel lateral force and the rear wheel lateral force, the saturation values ​​of the lateral force that are greater than the preset saturation state value are determined as saturation input indicators; Based on the difference between the saturation input index and the preset saturation state value, the target slip ratio of the vehicle is corrected to reduce the difference between the saturation input index and the preset saturation state value by reducing the target slip ratio.

7. The method according to claim 2, characterized in that, Determining the tire correction angle of the vehicle includes: For the saturation values ​​of the front wheel lateral force and the rear wheel lateral force, the saturation values ​​of the lateral force that are greater than the preset saturation state value are determined as saturation input indicators; The tire correction angle of the vehicle is determined based on the difference between the saturation input index and the preset saturation state value, so as to reduce the difference between the saturation input index and the preset saturation state value by means of the tire correction angle.

8. The method according to claim 1, characterized in that, Controlling the front and rear wheel steering angles of the vehicle based on the tire-corrected steering angle includes: The tire correction angle is distributed to the front and rear wheels of the vehicle according to a preset ratio to obtain the front wheel correction angle and the rear wheel correction angle; If the vehicle is understeer, the front and rear wheels are controlled to rotate in opposite directions according to the front wheel correction angle and the rear wheel correction angle, respectively. If the vehicle is oversteer, the front and rear wheels are controlled to rotate in the same direction according to the front wheel correction angle and the rear wheel correction angle, respectively.

9. An electronic device, characterized in that, The electronic device includes: Processor and memory; The processor executes the steps of the vehicle steering control method as described in any one of claims 1 to 8 by calling programs or instructions stored in the memory.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a program or instructions that cause a computer to perform the steps of the vehicle steering control method as described in any one of claims 1 to 8.

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