Vehicle steering control method, device and equipment

Abstract

The invention discloses a vehicle steering control method, device and equipment. The method comprises the steps that driving intention information is acquired; determining a target steering mode matched with the driving intention information from a plurality of preset steering modes of the vehicle; wherein the plurality of preset steering modes at least comprise a differential steering mode and a drift steering mode; adjusting steering control parameters of the vehicle based on the target steering mode; and based on the adjusted steering control parameters, the vehicle is controlled to conduct steering operation. The steering radius can be adaptively reduced under different steering types.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle control, in particular to a vehicle steering control method, device and equipment. BACKGROUND

[0002] In the process of vehicle steering, the turning radius determines the size of the site required for vehicle steering, and also relates to the passability and safety of the vehicle in extreme driving scenarios. In related technologies, the vehicle steering control method used to control the turning radius of the vehicle is relatively single, and the selectivity is poor, which cannot adapt the steering control operation of the vehicle to the steering requirements in different working conditions, resulting in poor precision of vehicle steering control. SUMMARY

[0003] One of the purposes of the present application is to provide a vehicle steering control method, device and equipment, which can reduce the turning radius required in the process of vehicle steering, and greatly improve the precision of vehicle steering control.

[0004] In order to achieve the above purpose, the technical solution adopted by the present application is as follows: The embodiment of the present application provides a vehicle steering control method, which comprises the following steps: obtaining driving intention information; determining a target steering mode matched with the driving intention information from a plurality of preset steering modes of the vehicle; wherein the plurality of preset steering modes at least include a differential steering mode and a drift steering mode; adjusting a steering control parameter of the vehicle based on the target steering mode; and controlling the vehicle to perform a steering operation based on the adjusted steering control parameter.

[0005] The embodiment of the present application provides a vehicle steering control device, which comprises: an intention obtaining unit configured to obtain driving intention information; a mode determining unit configured to determine a target steering mode matched with the driving intention information from a plurality of preset steering modes of the vehicle; wherein the target steering mode is a steering mode matched with the driving intention information in the plurality of preset steering modes, and the plurality of preset steering modes at least include a differential steering mode and a drift steering mode; a parameter adjusting unit configured to adjust a steering control parameter of the vehicle based on the target steering mode; a steering control unit configured to control the vehicle to perform a steering operation based on the adjusted steering control parameter.

[0006] The embodiment of the present application provides a vehicle steering control device, which comprises a processor and a storage medium storing executable instructions, the storage medium performs operations by relying on the processor, and when the executable instructions are executed by the processor, the vehicle steering control method of one or more embodiments described above is executed.

[0007] The embodiment of the present application provides a computer storage medium, which stores executable instructions, and when the executable instructions are executed by a processor, the processor executes a vehicle steering control method according to one or more embodiments.

[0008] The embodiment of the present application provides a computer program product, which comprises a computer program or instructions, and when the computer program or instructions are executed by a processor, a vehicle steering control method according to one or more embodiments is executed.

[0009] Advantages of the present application: In the present application, by setting multiple preset steering modes including a differential steering mode and a drift steering mode, and matching a corresponding target steering mode from the multiple preset steering modes according to driving intention information, the steering mode of the vehicle can be adapted to the differential steering demand or drift steering demand indicated by the current steering working condition; by adjusting the steering control parameters based on the target steering mode, and controlling the vehicle to perform a steering operation based on the adjusted steering control parameters, different types of steering control can be more accurate, so that the turning radius can be adaptively reduced under different steering types. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 An implementation flowchart of a vehicle steering control method according to the embodiment of the present application is provided. Figure 2 A schematic diagram of a vehicle Ackerman steering model according to the embodiment of the present application is provided. Figure 3 A schematic diagram of a vehicle seven-degree-of-freedom dynamics model according to the embodiment of the present application is provided. Figure 4 A schematic diagram of a distributed vehicle driving architecture according to the embodiment of the present application is provided. Figure 5 A schematic diagram of the composition structure of a vehicle steering control device according to the embodiment of the present application is provided. Figure 6 A schematic diagram of the composition structure of a vehicle steering control device according to the embodiment of the present application is provided. DETAILED DESCRIPTION

[0011] The embodiments of the present application will be described below with reference to the accompanying drawings and preferred embodiments, and other advantages and effects of the present application can be easily understood by those skilled in the art from the disclosure in the specification. The present application can also be implemented or applied by different specific embodiments, and various modifications or changes can be made to the details in the specification based on different views and applications without departing from the spirit of the present application. It should be understood that the preferred embodiments are only for illustrating the present application, and are not intended to limit the protection scope of the present application.

[0012] It is to be noted that the drawings provided in the following embodiments only schematically illustrate the basic concept of the present application, and only the components related to the present application are shown in the drawings, not drawn according to the number, shape and size of the components in actual implementation, and the type, number and proportion of each component in actual implementation can be arbitrarily changed, and the component layout type can also be more complex.

[0013] During the steering of the vehicle, the turning radius not only determines the size of the site required for the steering of the vehicle, but also is directly related to the passability and safety of the vehicle in scenes such as narrow streets, congested intersections, multi-level parking lots, mountain sharp curves or width-limited piers: the larger the radius, the wider the lateral space required by the vehicle, which often needs to reverse "rub the warehouse" to complete the turning, increasing the risk of scratching; the smaller the radius, the turning can be completed at a time in a limited width, reducing traffic congestion and operation intensity. Therefore, how to further reduce and correct the turning radius in the mechanical limit and dynamic constraint has become a core technical requirement to improve the traffic efficiency and driving safety of the vehicle.

[0014] A common vehicle steering control method, in the case where the steering control function is turned on, controls the front axle drive motor to apply corresponding positive driving torque to the front wheels of the vehicle and corresponding brake torque to the inside front wheels of the vehicle according to the front axle target deflection torque and the rear axle target deflection torque; controls the rear axle drive motor to apply corresponding reverse driving torque to the rear wheels of the vehicle and corresponding brake torque to the outside rear wheels of the vehicle according to the rear axle target deflection torque. However, the target deflection torque is obtained by a fixed calculation method, that is, the control parameters cannot be adjusted according to different working conditions of the vehicle, the selectivity is poor, the steering control operation of the vehicle cannot adapt to the steering requirements in different working conditions, and the precision of the vehicle steering control is poor.

[0015] Another vehicle steering control method reduces the turning radius of the vehicle by controlling the negative torque of the steering side rear wheel, the positive torque of the outside rear wheel, the braking of the inside front wheel of the vehicle and the positive rotation of the outside front wheel of the vehicle based on the target slip ratio and the actual slip ratio. Similarly, the determination method of the target slip ratio in this control method, and the calculation of the negative torque of the steering side rear wheel, the positive torque of the outside rear wheel, the braking of the inside front wheel of the vehicle and the positive rotation of the outside front wheel of the vehicle based on the target slip ratio and the actual slip ratio are all fixed calculation processes.

[0016] In summary, the common vehicle steering control method cannot achieve precise vehicle steering control for different working conditions, and the control effect in reducing the turning radius is not ideal.

[0017] To solve the above problems, the embodiment of the present application provides a vehicle steering control method, device and equipment, the method comprises the following steps: obtaining driving intention information; determining a target steering mode matched with the driving intention information from a plurality of preset steering modes of the vehicle; wherein the plurality of preset steering modes at least include a differential steering mode and a drift steering mode; adjusting a steering control parameter of the vehicle based on the target steering mode; controlling the vehicle to perform a steering operation based on the adjusted steering control parameter. In the present application, by setting a plurality of preset steering modes including a differential steering mode and a drift steering mode, and matching a corresponding target steering mode from them according to the driving intention information, the steering mode of the vehicle can be adapted to the differential steering demand or drift steering demand pointed by the current steering working condition; by adjusting the steering control parameter based on the target steering mode, and controlling the vehicle to perform a steering operation based on the adjusted steering control parameter, different types of steering control can be more accurate, so as to adaptively reduce the turning radius under different steering types.

[0018] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.

[0019] An embodiment of the present application provides a vehicle steering control method, which can be applied to a vehicle steering control device, a vehicle steering control equipment, and a vehicle equipment provided with the vehicle steering control device or the vehicle steering control equipment. The present application is not specifically limited.

[0020] It can be understood that, in the embodiments of the present application, the vehicle steering control method provided by the present application is exemplarily described below with the vehicle steering control device as the execution subject, but the execution subject of the vehicle steering control method is not limited.

[0021] In the embodiments of the present application, Figure 1 The implementation process of the vehicle steering control method provided by the embodiment of the present application is shown in the figure Figure 1 As shown in the figure Figure 1 The vehicle steering control device can include the following steps when performing vehicle steering control: Step 101, obtaining driving intention information.

[0022] In the embodiments of the present application, the driving intention information can be obtained before the steering control function is started, or the driving intention information can be obtained after the steering control function is started.

[0023] In the embodiments of the present application, when the driving intention information is acquired before the steering control function is turned on, the steering control function can be turned on in the following manner: after the driving operation parameters are recognized to obtain the driving intention information, the steering control function is automatically turned on if the driving intention information indicates that the user has a steering intention, and the subsequent steps in the vehicle steering control method are executed. For example, the driving operation parameters can include vehicle gear position, steering wheel angle, vehicle speed, brake pedal state, and the like. If the vehicle gear position is D, the steering wheel angle is greater than a preset steering angle threshold, the vehicle speed is less than a preset vehicle speed threshold, and the brake pedal state is released, the driving intention information indicating that the user has a steering intention is generated, and the steering control function is automatically turned on.

[0024] In the embodiments of the present application, when the driving intention information is acquired after the steering control function is turned on, the steering control function can be turned on according to different types of function control instructions of the user to determine whether the steering control function is turned on. The different types of function control instructions include touch type function control instructions and voice type function control instructions. The touch type function control instructions can be generated according to the touch operation of the user. After the user triggers the opening control corresponding to the steering control function, the steering control function opening instruction is generated and the steering control function is turned on. The voice type function control instructions can be generated according to the voice information of the user. After the voice information of the user indicates that the steering control function is turned on, the steering control function opening instruction is generated and the steering control function is turned on.

[0025] In step 102, a target steering mode matching the driving intention information is determined from a plurality of preset steering modes of the vehicle; wherein the target steering mode is a steering mode matching the driving intention information in the plurality of preset steering modes, and the plurality of preset steering modes at least include a differential steering mode and a drift steering mode.

[0026] In the embodiments of the present application, the vehicle steering degrees corresponding to different preset steering modes are different, that is, the vehicle steering degrees corresponding to the differential steering mode and the drift steering mode are different.

[0027] In the embodiments of the present application, the driving intention information can describe the vehicle steering degree, which indicates the size relationship between the actual generated or user expected sliding distance of the rear axle relative to the front axle during vehicle steering and the preset sliding distance. The sliding distance of the rear axle relative to the front axle can be understood as the distance of the sliding caused by the torque breakthrough of the left and right wheels of the rear axle of the vehicle on the road surface adhesion. The sliding distance corresponding to the differential steering mode is less than the preset sliding distance, and the sliding distance corresponding to the drift steering mode is greater than or equal to the preset sliding distance.

[0028] In the embodiments of the present application, in order to distinguish the differential steering mode and the drift steering mode, the preset slip distance can be in millimeter or centimeter level. In this way, when the driving intention information indicates that the slip distance is less than the preset slip distance, it can be considered that the rear axle left and right wheel torque does not break the road adhesion in the vehicle turning, and the differential steering mode is matched and the steering control operation in the differential steering mode is performed. When the driving intention information indicates that the slip distance is greater than or equal to the preset slip distance, it can be considered that the rear axle left and right wheel torque breaks the road adhesion in the vehicle turning, and the drift steering mode is matched and the steering control operation in the drift steering mode is performed.

[0029] For example, when the driving intention information indicates the size relationship between the actual slip distance of the rear axle relative to the front axle generated in the vehicle turning and the preset slip distance, the driving intention information can be generated by detecting the actual slip distance of the rear axle relative to the front axle generated in the driving process and comparing the detected slip distance with the preset slip distance. The target steering mode is determined, including determining the differential steering mode as the target steering mode when the driving intention information indicates that the detected slip distance is less than the preset slip distance, and determining the drift steering mode as the target steering mode when the driving intention information indicates that the detected slip distance is greater than or equal to the preset slip distance.

[0030] For example, when the driving intention information indicates the size relationship between the expected slip distance of the rear axle relative to the front axle generated in the vehicle turning and the preset slip distance, the driving intention information can be generated by obtaining the expected slip distance of the rear axle relative to the front axle generated in the vehicle turning and comparing the expected value with the preset slip distance. The target steering mode is determined, including determining the differential steering mode as the target steering mode when the driving intention information indicates that the expected slip distance is less than the preset slip distance, and determining the drift steering mode as the target steering mode when the driving intention information indicates that the expected slip distance is greater than or equal to the preset slip distance.

[0031] In the embodiments of the present application, a more convenient way of determining the target steering mode according to the driving intention information is also provided, including displaying a plurality of preset steering modes each corresponding to a selection control, and selecting the selection control in the plurality of preset steering modes according to the expected slip distance of the rear axle relative to the front axle generated in the vehicle turning to generate a corresponding selection instruction, which is the driving intention information. The target steering mode is determined in response to the selection control indicated by the selection instruction.

[0032] Step 103, adjusting the steering control parameter of the vehicle based on the target steering mode.

[0033] In the embodiments of the present application, the differential steering mode includes a plurality of sub-differential steering modes, and different sub-differential steering modes correspond to different vehicle suspension states. The vehicle suspension state can be provided by the suspension system of the vehicle, and the vehicle suspension state indicates the kingpin offset state of the front axle and the rear axle of the vehicle. In the general vehicle design, the front axle kingpin offset state is positive offset, and the rear axle kingpin offset state is positive / negative offset. Combining the front axle and rear axle kingpin offset states of the vehicle, two types of vehicle suspension states are obtained, one is front axle positive kingpin offset + rear axle positive kingpin offset, and the other is front axle positive kingpin offset + rear axle negative kingpin offset, where positive kingpin offset means that the tire force point of the tire is outside the tire center, and negative kingpin offset means that the tire force point of the tire is inside the tire center.

[0034] In the embodiments of the present application, when the target steering mode is the differential steering mode, the steering control parameter of the vehicle is adjusted based on the target steering mode, including: Step 1031, from the plurality of sub-differential steering modes, a target sub-differential steering mode matching the vehicle suspension state of the vehicle is determined.

[0035] In the embodiments of the present application, the sub-differential steering mode includes a first sub-differential steering mode and a second sub-differential steering mode. The first sub-differential steering mode corresponds to the vehicle suspension state of front axle positive kingpin offset + rear axle positive kingpin offset, that is, the vehicle suspension state corresponding to the first sub-differential steering mode indicates that the tire force point of the tire at the front axle of the vehicle is outside the tire center, and the tire force point of the tire at the rear axle of the vehicle is outside the tire center. The second sub-differential steering mode corresponds to the vehicle suspension state of front axle positive kingpin offset + rear axle negative kingpin offset, that is, the vehicle suspension state corresponding to the second sub-differential steering mode indicates that the tire force point of the tire at the front axle of the vehicle is outside the tire center, and the tire force point of the tire at the rear axle of the vehicle is inside the tire center. By accessing the configuration parameters of the suspension system of the vehicle, the target sub-differential steering mode matching the vehicle in the differential steering mode can be determined.

[0036] Step 1032, adjusting the steering control parameter based on the target sub-differential steering mode.

[0037] Therefore, in the embodiments of the present application, by matching the appropriate sub-differential steering mode for the vehicle based on the vehicle suspension state of the vehicle, the steering mode of the vehicle can be adapted to the vehicle suspension state condition of the vehicle; by adjusting the steering control parameter based on the adapted target sub-differential steering mode, the steering control of the vehicle with different vehicle suspension configurations can be more accurate, so as to adaptively reduce the turning radius under different vehicle suspension configurations.

[0038] In embodiments of the present invention, the steering control parameters in the differential steering mode include the front axle yaw control torque and the rear axle yaw control torque. Based on the target sub-differential steering mode, the steering control parameters are adjusted, including: Based on the vehicle speed and steering wheel angle, the original yaw rate of the vehicle is corrected to obtain the target yaw rate. The original yaw rate is the yaw rate calculated based on the vehicle's kinematic model.

[0039] In an embodiment of the present invention, the calculation process for obtaining the target yaw rate specifically includes: obtaining the vehicle's current original yaw rate. Speed And steering wheel angle, original yaw rate The yaw rate is calculated based on the vehicle's kinematic model, while the actual yaw rate is the measured yaw rate; the vehicle speed is determined based on a preset correction coefficient correspondence. Target correction coefficient corresponding to steering wheel angle Preset correction coefficient correspondence indicates vehicle speed The relationship between steering wheel angle and correction factor; based on the original yaw rate. and target correction coefficient The target yaw rate is obtained. .

[0040] The vehicle kinematics model uses the Ackermann steering model.

[0041] Figure 2 This is a schematic diagram of the vehicle Ackerman steering model proposed in an embodiment of the present invention. Figure 2 The x-axis is the reference direction. Let 'a' be the front wheel steering angle, and 'a' be the distance from the center of gravity to the front axle. The distance from the center of gravity to the rear axle. Center point of the front axle The center point of the rear axle The center of rotation of the vehicle under conditions of no lateral slip. The center of rotation of the vehicle under lateral deviation. The perpendicular line from the center of the vehicle to the center of the front and rear axles. The wheelbase is the distance between the front and rear axles. This represents the turning radius of the vehicle when steering without side slip. This refers to the turning radius corresponding to the vehicle's steering when there is lateral deviation. The rotational speed of the vehicle's center of gravity under conditions of no lateral slip. The rotational speed of the vehicle's center of gravity under lateral tilt conditions. The rotational speed of the front axle under no lateral slip conditions. the rotation speed of the front axle in the case of side slip, the rotation speed of the rear axle in the case of no side slip, the rotation speed of the rear axle in the case of side slip, the side slip angle of the front axle tire, the side slip angle of the rear axle tire. The original yaw rate is calculated based on a vehicle kinematics model by using the following formula (1): (1) ; In formula (1), is the original yaw rate, is the vehicle speed, is the front wheel steering angle, is the front-rear axle distance, m is the total vehicle mass, a is the distance from the mass center to the front axle, is the distance from the mass center to the rear axle, is the front wheel tire stiffness, is the rear wheel tire stiffness.

[0042] In the embodiment of the present application, the preset correction coefficient correspondence is a correction coefficient table indicating the correspondence between the vehicle speed and the steering wheel steering angle and the correction coefficient. The table is shown in Table 1. In the case of a vehicle speed of 5 and a steering wheel steering angle of 200, the target correction coefficient takes 1.1; in the case of a vehicle speed of 20 and a steering wheel steering angle of 500, the target correction coefficient takes 1.2.

[0043] Table 1 Correction coefficient table

[0044] In the embodiment of the present application, the target yaw rate is obtained according to the original yaw rate and the target correction coefficient , and is calculated by using the following formula (2): (2) ; In formula (2), is the target yaw rate, is the original yaw rate, is the target correction coefficient.

[0045] Based on a preset yaw feedforward torque correspondence, the target yaw feedforward torque corresponding to the vehicle speed and the steering wheel steering angle is determined, and the preset yaw feedforward torque correspondence indicates the correspondence among the vehicle speed, the steering wheel steering angle and the yaw feedforward torque.

[0046] In the embodiment of the present application, the preset yaw feedforward torque correspondence is a yaw feedforward torque table indicating the correspondence between the vehicle speed , the steering wheel angle and the yaw feedforward torque, and the unit of the yaw feedforward torque is Nm. The table is shown in Table 2. In the case where the vehicle speed is 5 and the steering wheel angle is -100, the target yaw feedforward torque is -600; in the case where the vehicle speed is 20 and the steering wheel angle is 500, the target yaw feedforward torque is 500.

[0047] Table 2 Yaw feedforward torque table

[0048] The torque analysis is performed according to the target yaw angular velocity and the actual yaw angular velocity of the vehicle, and the target yaw feedback torque is obtained, wherein the actual yaw angular velocity is the measured yaw angular velocity.

[0049] In the embodiment of the present application, the target yaw feedback torque is obtained by subtracting the actual yaw angular velocity of the vehicle from the target yaw angular velocity . , and the yaw angular velocity difference is obtained.

[0050] In the embodiment of the present application, the target yaw angular velocity is subtracted from the actual yaw angular velocity of the vehicle , and the yaw angular velocity difference is obtained, and is calculated by using the following formula (3): (3). In the formula (3), is the target yaw angular velocity, is the actual yaw angular velocity, and is the yaw angular velocity difference.

[0051] In the embodiment of the present application, the yaw angular velocity difference is subjected to proportional integral processing, and the target yaw feedback torque is obtained, and is calculated by using the following formula (4): (4). In the formula (4), is the target yaw feedback torque, is the proportional control item parameter, is the integral control item parameter, and is the yaw angular velocity difference.​​

[0052] The target yaw feedforward torque and the target yaw feedback torque are obtained.

[0053] In the embodiment of the present application, the target yaw torque is obtained The target yaw torque is obtained by using the following formula (5): (5) ; In formula (5), is the target yaw torque, is the target yaw feedforward torque, is the target yaw feedback torque.

[0054] Based on the vehicle speed, the steering wheel angle, the target yaw angular velocity, and the target yaw torque, the front axle yaw control torque and the rear axle yaw control torque in the target sub-differential steering mode are determined.

[0055] It can be seen that, in the embodiment of the present application, the original yaw angular velocity of the vehicle is corrected to obtain the target yaw angular velocity based on the vehicle speed and the steering wheel angle, and the target yaw feedforward torque corresponding to the vehicle speed and the steering wheel angle is determined based on the preset yaw feedforward torque corresponding relationship, so that the yaw feedforward torque of the vehicle and the original yaw angular velocity calculated based on the vehicle kinematic model are respectively corrected based on the real-time vehicle speed and the real-time steering wheel angle, so that the front axle yaw control torque and the rear axle yaw control torque of the vehicle are more in line with the real-time vehicle speed and the steering angle working condition, the real-time steering control is more accurate, and the control effect of the turning radius is greatly improved, and the turning radius is reduced.

[0056] In the embodiment of the present application, in the case that the target sub-differential steering mode is the first sub-differential steering mode, based on the vehicle speed, the steering wheel angle, the target yaw angular velocity, and the target yaw torque, the front axle yaw control torque and the rear axle yaw control torque in the target sub-differential steering mode are determined, comprising: Based on the preset yaw torque distribution coefficient corresponding relationship, the target yaw torque distribution coefficient corresponding to the vehicle speed and the steering wheel angle is determined, and the preset yaw torque distribution coefficient corresponding relationship indicates the corresponding relationship among the vehicle speed, the steering wheel angle, and the yaw torque distribution coefficient.

[0057] In the embodiment of the present application, the preset yaw torque distribution coefficient corresponding relationship is a yaw torque distribution coefficient table indicating the corresponding relationship among the vehicle speed , the steering wheel angle, and the yaw torque distribution coefficient. The table is shown in Table 3, in the case that the vehicle speed is 10 and the steering wheel angle is -100, the target yaw torque distribution coefficient is 0.5; in the case that the vehicle speed is 20 and the steering wheel angle is 500, the target yaw torque distribution coefficient Take 0.2.

[0058] Table 3 yaw feedforward torque table

[0059] The front and rear axles of the vehicle are allocated yaw torques based on the target yaw torque allocation coefficient and the steering yaw torque, to obtain a front axle allocated yaw torque and a rear axle allocated yaw torque.

[0060] In an embodiment of the application, the target yaw torque allocation coefficient is multiplied by the steering yaw torque to obtain the front axle allocated yaw torque . The difference between the constant 1 and the target yaw torque allocation coefficient is multiplied by the steering yaw torque to obtain the rear axle allocated yaw torque .

[0061] In an embodiment of the application, the front axle allocated yaw torque is calculated using the following formula (6): (6) ; In formula (6), is the front axle allocated yaw torque, is the steering yaw torque, is the target yaw torque allocation coefficient .

[0062] In an embodiment of the application, the rear axle allocated yaw torque is calculated using the following formula (7): (7) ; In formula (7), is the rear axle allocated yaw torque, is the steering yaw torque, is the target yaw torque allocation coefficient .

[0063] According to the target yaw angular velocity, wheel speed difference analysis is performed on the left and right wheels of the front axle and the left and right wheels of the rear axle respectively, to obtain a front axle target wheel speed difference and a rear axle target wheel speed difference.

[0064] In an embodiment of the application, the wheel speed difference of the left and right wheels of the front axle is analyzed according to the target yaw angular velocity to obtain the front axle target wheel speed difference , which comprises: multiplying the target yaw angular velocity by the front axle wheel track and then multiplying the result by the front axle differential steering correction coefficient to obtain the front axle target wheel speed difference Based on the target yaw rate The wheel speed difference between the left and right rear wheels was analyzed to obtain the target wheel speed difference of the rear axle. Includes: the target's yaw rate Rear axle track Multiply by the rear axle differential steering correction factor Multiply to obtain the target wheel speed difference on the rear axle. Among them, the front axle differential steering correction coefficient and rear axle differential steering correction factor All values ​​are calibration values, and the range is 1.1 to 1.5.

[0065] A dynamic analysis was performed on the target wheel speed difference and the actual wheel speed difference of the front axle to obtain the corrected yaw moment of the front axle. The actual wheel speed difference of the front axle is the measured wheel speed difference between the left and right wheels of the front axle.

[0066] In an embodiment of the present invention, the actual wheel speed difference of the front axle The wheel speed difference is calculated by subtracting the measured right wheel speed from the measured left wheel speed on the front axle, and then calculating the target wheel speed difference for the front axle. Difference between front axle and actual wheel speed Dynamic analysis was performed to obtain the front axle corrected yaw moment. Includes: the target wheel speed difference of the front axle Subtract the actual wheel speed difference of the front axle of the vehicle The front axle wheel speed deviation value is obtained. Front axle wheel speed deviation value By performing proportional-integral processing, the corrected yaw moment of the front axle is obtained. .

[0067] In an embodiment of the present invention, the front axle target wheel speed difference is... Subtract the actual wheel speed difference of the front axle of the vehicle The front axle wheel speed deviation value is obtained. The following formula (8) is used to calculate: (8); In equation (8), For the target wheel speed difference of the front axle, This represents the actual wheel speed difference of the front axle. This represents the front axle wheel speed deviation value.

[0068] In an embodiment of the present invention, the front axle wheel speed deviation value By performing proportional-integral processing, the corrected yaw moment of the front axle is obtained. The following formula (9) is used to calculate: (9); In equation (9), is a front axle correction yaw moment, is a proportional control term parameter, is an integral control term parameter, is a front axle wheel speed deviation value.

[0069] The rear axle correction yaw moment is obtained by performing dynamic analysis on the rear axle target wheel speed difference and the rear axle actual wheel speed difference, and the rear axle actual wheel speed difference is a measured difference between left and right wheel speeds of the rear axle.

[0070] In the embodiment of the present application, the rear axle actual wheel speed difference is a wheel speed difference value obtained by subtracting the measured right wheel speed of the rear axle from the measured left wheel speed of the rear axle, and the rear axle correction yaw moment is obtained by performing dynamic analysis on the rear axle target wheel speed difference and the rear axle actual wheel speed difference . In the embodiment of the present application, the rear axle target wheel speed difference is subtracted from the rear axle actual wheel speed difference of the vehicle to obtain a rear axle wheel speed deviation value , and the rear axle correction yaw moment is obtained by performing proportional integral processing on the rear axle wheel speed deviation value .

[0071] In the embodiment of the present application, the rear axle target wheel speed difference is subtracted from the rear axle actual wheel speed difference of the vehicle to obtain a rear axle wheel speed deviation value , and the rear axle correction yaw moment is obtained by using the following formula (10): (10) ; In formula (10), is the rear axle target wheel speed difference, is the rear axle actual wheel speed difference, and is the rear axle wheel speed deviation value. In the embodiment of the present application, the rear axle wheel speed deviation value

[0072] is subjected to proportional integral processing to obtain the rear axle correction yaw moment , and the rear axle correction yaw moment is obtained by using the following formula (11): (11) ; In formula (11), is the rear axle correction yaw moment, is a proportional control term parameter, is an integral control term parameter, and is the rear axle wheel speed deviation value.

[0073] ​The front axle yaw control moment is determined according to the sum of the front axle distribution yaw moment and the front axle correction yaw moment.

[0074] In the embodiment of the present application, the front axle distribution yaw moment and the front axle correction yaw moment are summed to determine the front axle yaw control moment .

[0075] The rear axle yaw control moment is determined according to the sum of the rear axle distribution yaw moment and the rear axle correction yaw moment.

[0076] In the embodiment of the present application, the rear axle distribution yaw moment and the rear axle correction yaw moment are summed to determine the rear axle yaw control moment .

[0077] Therefore, in the embodiment of the present application, the target yaw moment distribution coefficient corresponding to the vehicle speed and the steering wheel angle is determined based on the preset yaw moment distribution coefficient corresponding relationship, and the front and rear axles of the vehicle are distributed in terms of the yaw moment based on the target yaw moment distribution coefficient and the steering yaw moment, so that the front and rear axle yaw moment distribution process of the vehicle is more in line with the real-time vehicle speed and steering angle working condition. The front axle correction yaw moment and the rear axle correction yaw moment are obtained by analyzing the wheel speed difference of the front axle left and right wheels and the rear axle left and right wheels respectively according to the target yaw angular velocity, and further performing dynamic analysis, so that the yaw moment correction amount of the front and rear axles is more accurate. The front axle yaw control moment is obtained according to the front axle distribution yaw moment and the front axle correction yaw moment, and the rear axle yaw control moment is obtained according to the rear axle distribution yaw moment and the rear axle correction yaw moment, so that the yaw control moment required for steering control is more accurate, thereby greatly improving the control effect of the turning radius and reducing the turning radius.

[0078] In the embodiment of the present application, when the target sub-differential steering mode is the second sub-differential steering mode, the front axle yaw control moment and the rear axle yaw control moment in the target sub-differential steering mode are determined based on the vehicle speed, the steering wheel angle, the target yaw angular velocity and the steering yaw moment, comprising: The target reverse yaw moment corresponding to the vehicle speed and the steering wheel angle is determined based on the preset reverse yaw moment corresponding relationship, and the preset reverse yaw moment corresponding relationship indicates the corresponding relationship among the vehicle speed, the steering wheel angle and the reverse yaw moment. The direction of the reverse yaw moment is opposite to the current steering direction of the vehicle.

[0079] In the embodiment of the present application, the preset reverse yaw moment corresponding relationship is a corresponding relationship between the vehicle speed , the corresponding relationship between the steering wheel angle and the opposite yaw moment is an opposite yaw moment table, and the unit of the opposite yaw moment is Nm. The table is shown in Table 4. In the case where the vehicle speed is 10 and the steering wheel angle is -100, the target opposite yaw moment is -600; in the case where the vehicle speed is 20 and the steering wheel angle is 500, the target opposite yaw moment is 750.

[0080] Table 4: Opposite Yaw Moment Table

[0081] The difference between the steering yaw moment and the target opposite yaw moment is determined as the front axle basic yaw moment.

[0082] In the embodiment of the present application, the front axle basic yaw moment is obtained by subtracting the target opposite yaw moment from the steering yaw moment.

[0083] According to the target yaw angular velocity, wheel speed difference analysis is respectively performed on the left and right wheels of the front axle and the left and right wheels of the rear axle to obtain a front axle target wheel speed difference and a rear axle target wheel speed difference.

[0084] In the embodiment of the present application, according to the target yaw angular velocity , wheel speed difference analysis is respectively performed on the left and right wheels of the front axle and the left and right wheels of the rear axle to obtain a front axle target wheel speed difference and a rear axle target wheel speed difference. The specific implementation of obtaining the front axle target wheel speed difference and the rear axle target wheel speed difference is the same as the specific implementation of obtaining the front axle target wheel speed difference and the rear axle target wheel speed difference described above, and is not repeated here. Dynamics analysis is performed on the front axle target wheel speed difference and the front axle actual wheel speed difference to obtain a front axle correction yaw moment, and the front axle actual wheel speed difference is a measured front axle left and right wheel speed difference.

[0085] In the embodiment of the present application, dynamics analysis is performed on the front axle target wheel speed difference and the front axle actual wheel speed difference to obtain the specific implementation of the front axle correction yaw moment , which is the same as the specific implementation of obtaining the front axle correction yaw moment in the first sub-differential steering mode described above, and is not repeated here.

[0086] Dynamics analysis is performed on the rear axle target wheel speed difference and the rear axle actual wheel speed difference to obtain a rear axle correction yaw moment, and the rear axle actual wheel speed difference is a measured rear axle left and right wheel speed difference.

[0087] In the embodiment of the present application, dynamics analysis is performed on the rear axle target wheel speed difference and the rear axle actual wheel speed difference​ The dynamics analysis is performed to obtain the rear axle corrected yaw moment The specific implementation of the rear axle corrected yaw moment is the same as the specific implementation of the rear axle corrected yaw moment obtained in the first sub-differential steering mode, and is not repeated here.

[0088] The front axle yaw control moment is obtained according to the front axle basic yaw moment and the front axle corrected yaw moment.

[0089] In an embodiment of the present application, the sum of the front axle basic yaw moment and the front axle corrected yaw moment is determined as the front axle yaw control moment .

[0090] The rear axle yaw control moment is obtained according to the target reverse yaw moment and the rear axle corrected yaw moment.

[0091] In an embodiment of the present application, the sum of the target reverse yaw moment and the rear axle corrected yaw moment is determined as the rear axle yaw control moment .

[0092] Therefore, in an embodiment of the present application, the target reverse yaw moment corresponding to the vehicle speed and the steering wheel angle is determined based on the preset reverse yaw moment corresponding relationship, and the difference between the steering yaw moment and the target reverse yaw moment is determined as the front axle basic yaw moment, which can make the reverse yaw moment and the front axle basic yaw moment of the vehicle more consistent with the real-time vehicle speed and steering angle working condition. The front axle and rear axle are analyzed according to the target yaw angular velocity, and further dynamics analysis is performed to obtain the front axle corrected yaw moment and the rear axle corrected yaw moment, which can make the yaw control moment required for steering control more accurate, thereby greatly improving the control effect of the turning radius and reducing the turning radius.

[0093] In an embodiment of the present application, the drift steering mode includes a plurality of sub-drift steering modes, and the direction relationship between the first target moment and the second target moment corresponding to different sub-drift steering modes is different, the first target moment is the active yaw moment of the rear axle of the vehicle, and the second target moment is the inertial moment of the vehicle. The direction relationship between the first target moment and the second target moment can be calculated based on the seven-degree-of-freedom model of the vehicle at the initial stage of vehicle steering to obtain the direction relationship between the first target moment and the second target moment.

[0094] Figure 3A schematic diagram of a vehicle seven-degree-of-freedom dynamics model proposed for an embodiment of the present application. Figure 3 Each parameter in the above formula is the value in the reference coordinate of the vehicle speed in the x direction , the vehicle speed in the y direction , and the rotation angle γ. Taking the center of the front axle as the origin and ignoring the yaw moment generated by the left and right wheels of the front axle, the following vehicle seven-degree-of-freedom dynamics formula is obtained: Formula (12); In formula (12), is the longitudinal force of the left front wheel, is the longitudinal force of the right front wheel, is the rotation angle of the front wheel, is the front axle track, is the rear axle track, is the longitudinal force of the left rear wheel, is the longitudinal force of the right rear wheel, is the front-rear axle distance, M is the mass of the vehicle, is the distance from the center of mass to the front axle, is the longitudinal acceleration, is the moment of inertia, is the target yaw angular velocity.

[0095] Under the above vehicle seven-degree-of-freedom dynamics model, the first target moment can be represented as , and the second target moment can be represented as .

[0096] In the case where the target steering mode is the drift steering mode, based on the target steering mode, the steering control parameters of the vehicle are adjusted, including: Step 1031': determining a target sub-drift steering mode that matches the directional relationship between the first target moment and the second target moment of the vehicle from a plurality of sub-drift steering modes.

[0097] In an embodiment of the present application, the sub-drift steering mode includes a first sub-drift steering mode and a second sub-drift steering mode. The first sub-drift steering mode corresponds to a directional relationship in which the first target moment and the second target moment are in the same direction, i.e., fast drift, and the second sub-drift steering mode corresponds to a directional relationship in which the first target moment and the second target moment are in opposite directions, i.e., slow drift. By calculating the first target moment and the second target moment at the initial stage of vehicle steering and identifying the directional relationship between the two, the target sub-drift steering mode that matches the vehicle in the drift steering mode can be determined.

[0098] Step 1032': adjusting the steering control parameters based on the target sub-drift steering mode.

[0099] Therefore, in the embodiment of the present application, by matching the appropriate sub-drift steering mode for the vehicle based on the directional relationship between the first target torque and the second target torque, the steering mode of the vehicle can be adapted to the drift speed condition; by adjusting the steering control parameters based on the adapted target sub-drift steering mode, the steering control of the vehicle during the drift at different speeds can be more accurate, so that the turning radius can be adaptively reduced during the drift at different speeds.

[0100] In the embodiment of the present application, the steering control parameters in the drift steering mode include front axle yaw control torque and rear axle control wheel speed, and adjusting the steering control parameters based on the target sub-drift steering mode includes: Based on the vehicle speed and the steering wheel angle, the original yaw angular velocity of the vehicle is corrected to obtain the target yaw angular velocity, and the original yaw angular velocity is the yaw angular velocity calculated based on the kinematic model of the vehicle.

[0101] In the embodiment of the present application, the specific implementation process of obtaining the target yaw angular velocity is the same as the specific implementation process of obtaining the target yaw angular velocity in the differential steering mode described above, and will not be repeated here.

[0102] According to the vehicle speed, the steering wheel angle, the target yaw angular velocity, and the corresponding rear axle track of the vehicle, the respective basic wheel speeds of the left and right wheels of the rear axle are obtained.

[0103] In the embodiment of the present application, according to the vehicle speed , the steering wheel angle, the target yaw angular velocity , and the corresponding rear axle track of the vehicle , the respective basic wheel speeds of the left and right wheels of the rear axle are obtained, including: Based on the first preset slip rate corresponding relationship, the first target slip rate corresponding to the vehicle speed and the steering wheel angle is determined, and the first preset slip rate corresponding relationship indicates the corresponding relationship between the vehicle speed, the steering wheel angle and the rear axle left wheel calibration slip rate in the target sub-drift steering mode.

[0104] In the embodiment of the present application, the first preset slip rate corresponding relationship is a rear axle left wheel calibration slip rate table indicating the corresponding relationship between the vehicle speed , the steering wheel angle and the rear axle left wheel calibration slip rate. Taking the rear axle left wheel as the inside turning wheel as an example, the table is shown in Table 5, in the case that the vehicle speed is 5 and the steering wheel angle is 100, the first target slip rate takes -0.5; in the case that the vehicle speed is 20 and the steering wheel angle is 500, the first target slip rate takes -0.5.

[0105] Table 5 Rear axle left wheel calibration slip rate table

[0106] The second target slip ratio corresponding to the vehicle speed and the steering wheel angle is determined based on a second preset slip ratio correspondence relationship, and the second preset slip ratio correspondence relationship indicates a correspondence relationship among the vehicle speed, the steering wheel angle, and the right rear wheel calibrated slip ratio in the target sub-drifting turning mode.

[0107] In the embodiment of the application, the second preset slip ratio correspondence relationship is a right rear wheel calibrated slip ratio table indicating a correspondence relationship among the vehicle speed , the steering wheel angle, and the right rear wheel calibrated slip ratio. Taking the right rear wheel as the turning outside wheel as an example, the table is shown in Table 6. In the case where the vehicle speed is 5 and the steering wheel angle is 300, the second target slip ratio is 1; in the case where the vehicle speed is 20 and the steering wheel angle is 100, the second target slip ratio is 0.1.

[0108] Table 6 Right rear wheel calibrated slip ratio table

[0109] The first basic speed is obtained according to the vehicle speed, the first target slip ratio, the target yaw rate, and the rear wheel track corresponding to the vehicle, and the first basic speed is the basic wheel speed corresponding to the left rear wheel.

[0110] In the embodiment of the application, the first basic speed is obtained by calculation using the following formula (13): (13) ; In formula (13), is the first basic speed, is the vehicle speed, is the target yaw rate, is the rear wheel track, and is the first target slip ratio.

[0111] The second basic speed is obtained according to the vehicle speed, the second target slip ratio, the target yaw rate, and the rear wheel track corresponding to the vehicle, and the second basic speed is the basic wheel speed corresponding to the right rear wheel.

[0112] In the embodiment of the application, the second basic speed is obtained by calculation using the following formula (14): (14) ; In formula (14), is the second basic speed, is the vehicle speed, is the target yaw rate, is the rear wheel track, and is the second target slip ratio.

[0113] Therefore, in the embodiment of the application, the first target slip ratio corresponding to the vehicle speed and the steering wheel angle is determined based on the first preset slip ratio corresponding relationship, and the second target slip ratio corresponding to the vehicle speed and the steering wheel angle is determined based on the second preset slip ratio corresponding relationship, so that the slip ratios of the left and right wheels of the rear axle of the vehicle are more consistent with the real-time vehicle speed and the steering angle working condition of the vehicle; the basis wheel speed corresponding to each of the left and right wheels of the rear axle is obtained according to the vehicle speed, each target slip ratio, the target yaw rate, and the wheel base of the rear axle of the vehicle, so that the wheel speed parameter required for drift steering control is more accurate, and the control effect of the turning radius is greatly improved, and the turning radius is reduced.

[0114] The wheel speed is analyzed according to the target yaw rate and the actual yaw rate of the vehicle to obtain the rear axle correction wheel speed, and the actual yaw rate is a measured yaw rate.

[0115] In the embodiment of the application, the rear axle correction wheel speed is obtained by subtracting the actual yaw rate of the vehicle from the target yaw rate to obtain a yaw rate difference value ; and the yaw rate difference value is subjected to proportional-integral processing to obtain the rear axle correction wheel speed .

[0116] In the embodiment of the application, the target yaw rate is subtracted from the actual yaw rate of the vehicle to obtain a yaw rate difference value , which is calculated by using the following formula (15): (15) ; In formula (15), is the target yaw rate, is the actual yaw rate, and is the yaw rate difference value.

[0117] In the embodiment of the application, the yaw rate difference value is subjected to proportional-integral processing to obtain the rear axle correction wheel speed , which is calculated by using the following formula (16): (16) ; In formula (16), is the rear axle correction wheel speed, is a proportional control item parameter, is an integral control item parameter, and is the yaw rate difference value.

[0118] ​Determine the target control wheel speed corresponding to the left and right wheels of the rear axle based on the basic wheel speed corresponding to the left and right wheels of the rear axle, the rear axle correction wheel speed and the steering wheel angle, and the target control wheel speed corresponding to the left and right wheels of the rear axle belongs to the rear axle control wheel speed.

[0119] In the embodiment of the application, the target control wheel speed corresponding to the left and right wheels of the rear axle is determined based on the basic wheel speed corresponding to the left and right wheels of the rear axle, the rear axle correction wheel speed and the steering wheel angle, and the target control wheel speed corresponding to the left and right wheels of the rear axle belongs to the rear axle control wheel speed. Determine the sign bit corresponding to the rear axle correction wheel speed according to the steering wheel angle.

[0120] In the embodiment of the application, the sign bit corresponding to the rear axle correction wheel speed is 1 when the steering wheel angle is positive, -1 when the steering wheel angle is negative, and 0 when the steering wheel angle is 0.

[0121] Obtain the target control wheel speed corresponding to the left and right wheels of the rear axle according to the basic wheel speed corresponding to the left and right wheels of the rear axle, the rear axle correction wheel speed and the sign bit.

[0122] In the embodiment of the application, the target control wheel speed corresponding to the left wheel of the rear axle is obtained according to the basic wheel speed corresponding to the left wheel of the rear axle, the rear axle correction wheel speed and the sign bit, and is calculated by the following formula (17): (17) ; In formula (17), is the target control wheel speed corresponding to the left wheel of the rear axle, is the basic wheel speed corresponding to the left wheel of the rear axle, is the rear axle correction wheel speed, and is the sign bit.

[0123] In the embodiment of the application, the target control wheel speed corresponding to the left wheel of the rear axle is obtained according to the basic wheel speed corresponding to the left wheel of the rear axle, the rear axle correction wheel speed and the sign bit, and is calculated by the following formula (18): (18) ; In formula (18), is the target control wheel speed corresponding to the right wheel of the rear axle, is the basic wheel speed corresponding to the right wheel of the rear axle, is the rear axle correction wheel speed, and ​​​​​​​​​​​This is the sign bit.

[0124] Based on the preset yaw feedforward torque correspondence, the target yaw feedforward torque corresponding to the vehicle speed and steering wheel angle is determined. The preset yaw feedforward torque correspondence indicates the correspondence between vehicle speed, steering wheel angle and yaw feedforward torque.

[0125] In an embodiment of the present invention, the vehicle speed is determined based on a preset yaw feedforward torque correspondence. Target yaw feedforward torque corresponding to steering wheel angle The specific implementation method is the same as the target yaw feedforward moment determined in the aforementioned differential steering mode. The specific implementation method is the same, and will not be described in detail here.

[0126] Torque analysis is performed based on the target yaw rate and the vehicle's actual yaw rate to obtain the target yaw feedback torque. The actual yaw rate is the measured yaw rate.

[0127] In an embodiment of the present invention, based on the target yaw rate and the vehicle's actual yaw rate Torque analysis was performed to obtain the target yaw feedback torque. The specific implementation method is the same as the target yaw feedforward moment determined in the aforementioned differential steering mode. The specific implementation method is the same, and will not be described in detail here.

[0128] The steering yaw moment is obtained based on the target yaw feedforward moment and the target yaw feedback moment.

[0129] In an embodiment of the present invention, the target yaw feedforward torque is... and target yaw feedback torque The sum of these is determined as the steering yaw moment. .

[0130] Based on the target yaw rate, the wheel speed difference between the left and right front axles is analyzed to obtain the target wheel speed difference of the front axle.

[0131] In an embodiment of the present invention, based on the target yaw rate By analyzing the wheel speed difference between the left and right wheels of the front axle, the target wheel speed difference of the front axle is obtained. The specific implementation method is the same as the method for obtaining the target wheel speed difference of the front axle in the aforementioned differential steering mode. The specific implementation method is the same, and will not be described in detail here.

[0132] A dynamic analysis was performed on the target wheel speed difference and the actual wheel speed difference of the front axle to obtain the corrected yaw moment of the front axle. The actual wheel speed difference of the front axle is the measured wheel speed difference between the left and right wheels of the front axle.

[0133] In the embodiment of the present application, the front axle target wheel speed difference and the front axle actual wheel speed difference are subjected to dynamic analysis to obtain the front axle corrected yaw moment The specific implementation of the front axle corrected yaw moment in the differential steering mode is the same as the foregoing, and will not be repeated here.

[0134] Based on the steering yaw moment and the front axle corrected yaw moment, the front axle yaw control moment in the target sub-drift steering mode is obtained.

[0135] As can be seen, in the embodiment of the present application, by analyzing the front axle yaw control moment and the respective target control wheel speed of the left and right wheels of the rear axle in the drift steering mode according to the working condition parameters of the vehicle, adaptive control parameter analysis can be performed on the front axle and the rear axle in the drift process to reduce the turning radius of the vehicle in the drift state.

[0136] In the embodiment of the present application, the sub-drift steering mode includes a first sub-drift steering mode, and the corresponding directional relationship of the first sub-drift steering mode is that the first target moment and the second target moment are in the same direction. In the case where the target sub-drift steering mode is the first sub-drift steering mode, based on the steering yaw moment and the front axle corrected yaw moment, the front axle yaw control moment in the target sub-drift steering mode is obtained, including: The sum of the steering yaw moment and the front axle corrected yaw moment is determined as the front axle yaw control moment.

[0137] As can be seen, in the embodiment of the present application, by determining the sum of the steering yaw moment and the front axle corrected yaw moment as the front axle yaw control moment in the first sub-drift steering mode, more accurate control can be performed on the front axle yaw control moment in the relatively fast drift process to reduce the turning radius of the vehicle in the fast drift state.

[0138] In the embodiment of the present application, the sub-drift steering mode includes a second sub-drift steering mode, and the corresponding directional relationship of the second sub-drift steering mode is that the first target moment and the second target moment are in opposite directions. In the case where the target sub-drift steering mode is the second sub-drift steering mode, based on the steering yaw moment and the front axle corrected yaw moment, the front axle yaw control moment in the target sub-drift steering mode is obtained, including: The lateral acceleration is analyzed according to the vehicle speed and the target yaw angular velocity to obtain the original lateral acceleration.

[0139] In the embodiment of the present application, the product of the vehicle speed and the target yaw angular velocity is determined as the original lateral acceleration .

[0140] Based on the preset yaw compensation coefficient correspondence, the target yaw compensation coefficient corresponding to the lateral acceleration difference and vehicle speed is determined. The lateral acceleration difference is the difference between the original lateral acceleration and the actual lateral acceleration, and the actual lateral acceleration is the measured lateral acceleration of the vehicle.

[0141] In an embodiment of the present invention, the preset yaw compensation coefficient correspondence is the indicated vehicle speed. Table 7 shows the relationship between steering wheel angle and yaw compensation coefficient. The table details the target yaw compensation coefficient at a vehicle speed of 5 km / h and a steering wheel angle of 30°. Set to 1; With the vehicle speed at 20 km / h and the steering wheel angle at 100°, the target yaw compensation coefficient is... Take 0.1.

[0142] Table 7 Yaw Compensation Coefficient Table

[0143] The rear axle yaw moment is determined based on the torque of the left and right wheels of the rear axle, the rear axle track, and the tire rolling radius.

[0144] In an embodiment of the present invention, the rear axle yaw moment is determined. The following formula (19) is used to calculate: (19); In equation (19), This is the rear axle yaw moment. This is the torque corresponding to the left rear wheel. This is the torque corresponding to the right rear axle wheel. The rear axle track. This is the tire's rolling radius.

[0145] The front axle yaw compensation moment is determined based on the target yaw compensation coefficient and the rear axle yaw moment.

[0146] In an embodiment of the present invention, the target yaw compensation coefficient is... and rear axle yaw moment The product of these factors is determined as the front axle yaw moment compensation. .

[0147] The front axle yaw control torque is obtained based on the steering yaw moment, the front axle corrected yaw moment, and the front axle compensated yaw moment.

[0148] In an embodiment of the invention, the steering yaw moment is... Subtract front axle yaw moment The difference between the front axle yaw correction moment and the front axle correction moment. Adding them together, we get the front axle yaw control torque. .

[0149] Therefore, in the embodiment of the present application, by calculating the front axle compensation yaw moment in the second sub-drift turning mode, and obtaining the front axle yaw control moment according to the steering yaw moment, the front axle correction yaw moment and the front axle compensation yaw moment, the front axle yaw control moment in the relatively slow drift process can be more accurately controlled to reduce the turning radius of the vehicle in the fast drift state.

[0150] Step 104, controlling the vehicle to perform the steering operation based on the adjusted steering control parameter.

[0151] Figure 4 The schematic diagram of the distributed vehicle driving architecture proposed in the embodiment of the present application, in the embodiment of the present application, the vehicle can be a distributed vehicle, that is, each wheel is independently equipped with a driving unit (hub motor or wheel motor) to realize wheel-level independent control.

[0152] In the embodiment of the present application, the adjusted steering control parameter in the differential steering mode includes the front axle yaw control moment and the rear axle yaw control moment, and the vehicle is controlled to perform the steering operation based on the adjusted steering control parameter, including: Step 1041, obtaining a first original torque, a second original torque, a third original torque and a fourth original torque, the first original torque being an original torque of a front axle left wheel motor, the second original torque being an original torque of a front axle right wheel motor, the third original torque being an original torque of a rear axle left wheel motor, and the fourth original torque being an original torque of a rear axle right wheel motor.

[0153] In the embodiment of the present application, the first original torque , the second original torque , the third original torque and the fourth original torque are respectively original torques output by the front axle left wheel motor, the front axle right wheel motor, the rear axle left wheel motor and the rear axle right wheel motor according to original control instructions before the vehicle steering control is performed without enabling the steering control function.

[0154] Step 1042, correcting the first original torque according to the front axle yaw control moment, a front axle left wheel tire radius, a front axle track and a front axle rotation angle to obtain a first target torque.

[0155] In the embodiment of the present application, the first target torque can be calculated by using the following formula (20): (20) ; In formula (20), is the first target torque, is a first original torque, is a front axle yaw control torque, is a front axle left wheel tire radius, is a front axle track, is a front axle steering angle.

[0156] Step 1043, correcting the second original torque according to the front axle yaw control torque, the front axle right wheel tire radius, the front axle track and the front axle steering angle, to obtain a second target torque.

[0157] In the embodiment of the present application, the second target torque is obtained by The second target torque can be obtained by using the following formula (21): (21) ; In formula (21), is a second target torque, is a second original torque, is a front axle yaw control torque, is a front axle right wheel tire radius, is a front axle track, is a front axle steering angle.

[0158] Step 1044, correcting the third original torque according to the rear axle yaw control torque, the rear axle left wheel tire radius and the rear axle track, to obtain a third target torque.

[0159] In the embodiment of the present application, the third target torque is obtained by The third target torque can be obtained by using the following formula (22): (22) ; In formula (22), is a third target torque, is a third original torque, is a rear axle yaw control torque, is a rear axle left wheel tire radius, is a rear axle track.

[0160] Step 1045, correcting the fourth original torque according to the rear axle yaw control torque, the rear axle right wheel tire radius and the rear axle track, to obtain a fourth target torque.

[0161] In the embodiment of the present application, the fourth target torque is obtained by The fourth target torque can be obtained by using the following formula (23): (23) ; In formula (23), is a fourth target torque, is a fourth original torque, is a rear axle yaw control torque, is a front axle right wheel tire radius, is a front axle track.

[0162] Step 1046, based on the first target torque, the second target torque, the third target torque and the fourth target torque, control the vehicle to perform the steering operation.

[0163] In the embodiment of the application, based on the first target torque, the second target torque, the third target torque and the fourth target torque, controlling the vehicle to perform the steering operation includes: controlling the front axle left wheel motor, the front axle right wheel motor, the rear axle left wheel motor and the rear axle right wheel motor of the vehicle to output torques of the first target torque, the second target torque, the third target torque and the fourth target torque respectively, so as to complete the vehicle steering.

[0164] Therefore, in the embodiment of the application, by correcting the first original torque, the second original torque, the third original torque and the fourth original torque respectively, the output torques of the four-wheel motors in the differential steering process of the distributed vehicle can be effectively controlled, so as to reduce the turning radius of the vehicle under differential steering.

[0165] In the embodiment of the application, the adjusted steering control parameters in the aforementioned drift steering mode include the front axle yaw control moment and the target control wheel speed corresponding to each of the left and right wheels of the rear axle, and based on the adjusted steering control parameters, the vehicle is controlled to perform the steering operation, which includes: Step 1041', obtaining the first original torque and the second original torque, the first original torque being the original torque of the front axle left wheel motor, and the second original torque being the original torque of the front axle right wheel motor.

[0166] In the embodiment of the application, the first original torque and the second original torque are respectively the original torques output by the front axle left wheel motor and the front axle right wheel motor according to the original control instructions before the vehicle steering control without enabling the steering control function.

[0167] Step 1042', correcting the first original torque according to the front axle yaw control moment, the front axle left wheel tire radius, the front axle track and the front axle turning angle, to obtain the first target torque.

[0168] In the embodiment of the application, the specific implementation of obtaining the first target torque is the same as the specific implementation of obtaining the first target torque in the aforementioned differential steering mode, which will not be repeated here.

[0169] Step 1043', correcting the second original torque according to the front-axis yaw control moment, the front-axis right-wheel tire radius, the front-axis wheelbase and the front-axis rotation angle, to obtain a second target torque.

[0170] In the embodiment of the application, the second target torque is obtained by the same method as that of obtaining the second target torque in the differential steering mode, which is not repeated here.

[0171] Step 1044', obtaining a first target rotation speed according to the target control wheel speed corresponding to the rear-axis left wheel, the rear-axis transmission ratio and the rear-axis left-wheel tire radius, the first target rotation speed being the target rotation speed of the rear-axis left wheel.

[0172] In the embodiment of the application, the first target rotation speed is obtained by the following formula (24): (24) ; In formula (24), is the first target rotation speed, is the target control wheel speed corresponding to the rear-axis left wheel, is the rear-axis transmission ratio, and is the rear-axis left-wheel tire radius.

[0173] Step 1045', obtaining a second target rotation speed according to the target control wheel speed corresponding to the rear-axis right wheel, the rear-axis transmission ratio and the rear-axis right-wheel tire radius, the second target rotation speed being the target rotation speed of the rear-axis right wheel.

[0174] In the embodiment of the application, the second target rotation speed is obtained by the following formula (25): (25) ; In formula (25), is the second target rotation speed, is the target control wheel speed corresponding to the rear-axis right wheel, is the rear-axis transmission ratio, and is the rear-axis right-wheel tire radius.

[0175] Step 1046', controlling the vehicle to perform a steering operation based on the first target torque, the second target torque, the first target rotation speed and the second target rotation speed.

[0176] In the embodiment of the present application, based on the first target torque, the second target torque, the first target rotating speed and the second target rotating speed, the control of the vehicle to perform the steering operation comprises: controlling the front axle left wheel motor and the front axle right wheel motor of the vehicle to output torque at the first target torque and the second target torque respectively, and controlling the rear axle left wheel motor and the rear axle right wheel motor of the vehicle to output rotating speed at the first target rotating speed and the second target rotating speed respectively, so as to complete the steering of the vehicle.

[0177] Therefore, in the embodiment of the present application, the first original torque and the second original torque are respectively corrected, and the target rotating speeds of the left and right wheels of the rear axle under the rotating speed control are determined, so that the output of the four-wheel motor in the drifting steering process of the distributed vehicle can be effectively controlled, and the turning radius of the vehicle under the differential steering is reduced.

[0178] The embodiment of the present application provides a vehicle steering control method, obtains driving intention information, determines a target steering mode matched with the driving intention information from a plurality of preset steering modes of a vehicle, wherein the plurality of preset steering modes at least include a differential steering mode and a drifting steering mode, adjusts a steering control parameter of the vehicle based on the target steering mode, and controls the vehicle to perform a steering operation based on the adjusted steering control parameter. Therefore, in the present application, the plurality of preset steering modes including the differential steering mode and the drifting steering mode are set, and the corresponding target steering mode is matched according to the driving intention information, so that the steering mode of the vehicle can adapt to the differential steering demand or the drifting steering demand indicated by the current steering working condition; by adjusting the steering control parameter based on the target steering mode and controlling the vehicle to perform the steering operation based on the adjusted steering control parameter, different types of steering control can be more accurate, so that the turning radius can be adaptively reduced under different steering types.

[0179] Based on the same application concept as the foregoing embodiment, the embodiment of the present application provides a vehicle steering control device, Figure 5 The composition structure diagram of the vehicle steering control device provided by the embodiment of the present application is shown in Figure 5 As shown in the figure, the vehicle steering control device 5 includes an intention acquisition unit 51, a mode determination unit 52, a parameter adjustment unit 53 and a steering control unit 54.

[0180] The intention acquisition unit 51 is used for obtaining driving intention information. The mode determination unit 52 is used for determining a target steering mode matched with the driving intention information from a plurality of preset steering modes of a vehicle, wherein the plurality of preset steering modes at least include a differential steering mode and a drifting steering mode. The parameter adjustment unit 53 is used for adjusting a steering control parameter of the vehicle based on the target steering mode. The turning control unit 54 is configured to control the vehicle to perform a turning operation based on the adjusted turning control parameter.

[0181] In some embodiments, the differential turning mode includes a plurality of sub-differential turning modes, different sub-differential turning modes correspond to different vehicle suspension states, and the parameter adjustment unit 53 is further configured to: determine a target sub-differential turning mode that matches the vehicle suspension state of the vehicle from the plurality of sub-differential turning modes; and adjust the turning control parameter based on the target sub-differential turning mode.

[0182] In some embodiments, the turning control parameter in the differential turning mode includes a front axle yaw control moment and a rear axle yaw control moment, and the parameter adjustment unit 53 is further configured to: correct an original yaw angular velocity of the vehicle to obtain a target yaw angular velocity based on a vehicle speed and a steering wheel angle, the original yaw angular velocity being a yaw angular velocity calculated based on a vehicle kinematics model; determine a target yaw feedforward moment corresponding to the vehicle speed and the steering wheel angle based on a preset yaw feedforward moment correspondence, the preset yaw feedforward moment correspondence indicating a correspondence between the vehicle speed, the steering wheel angle, and the yaw feedforward moment; obtain a target yaw feedback moment through moment analysis based on the target yaw angular velocity and an actual yaw angular velocity of the vehicle, the actual yaw angular velocity being a measured yaw angular velocity; obtain a turning yaw moment based on the target yaw feedforward moment and the target yaw feedback moment; and determine the front axle yaw control moment and the rear axle yaw control moment in the target sub-differential turning mode based on the vehicle speed, the steering wheel angle, the target yaw angular velocity, and the turning yaw moment.

[0183] In some embodiments, the sub-differential steering mode includes a first sub-differential steering mode, the vehicle suspension state corresponding to the first sub-differential steering mode indicates that the tire force points of the tires at the front axle of the vehicle are outside the tire centers, and the tire force points of the tires at the rear axle of the vehicle are outside the tire centers, and when the target sub-differential steering mode is the first sub-differential steering mode, the parameter adjustment unit 53 is further configured to: determine a target yaw moment distribution coefficient corresponding to the vehicle speed and the steering wheel angle based on a preset yaw moment distribution coefficient correspondence relationship, the preset yaw moment distribution coefficient correspondence relationship indicating a correspondence relationship among the vehicle speed, the steering wheel angle, and the yaw moment distribution coefficient; distribute the yaw moment to the front axle and the rear axle of the vehicle based on the target yaw moment distribution coefficient and the steering yaw moment to obtain a front axle distribution yaw moment and a rear axle distribution yaw moment; perform wheel speed difference analysis on the front axle left and right wheels and the rear axle left and right wheels respectively according to the target yaw angular velocity to obtain a front axle target wheel speed difference and a rear axle target wheel speed difference; perform dynamics analysis on the front axle target wheel speed difference and an actual front axle wheel speed difference to obtain a front axle correction yaw moment, the actual front axle wheel speed difference being a measured front axle left and right wheel speed difference; perform dynamics analysis on the rear axle target wheel speed difference and an actual rear axle wheel speed difference to obtain a rear axle correction yaw moment, the actual rear axle wheel speed difference being a measured rear axle left and right wheel speed difference; and obtain a front axle yaw control moment based on the front axle distribution yaw moment and the front axle correction yaw moment, and obtain a rear axle yaw control moment based on the rear axle distribution yaw moment and the rear axle correction yaw moment.

[0184] In some embodiments, the sub-differential steering mode includes a second sub-differential steering mode, the vehicle suspension state corresponding to the second sub-differential steering mode indicates that the tire force points of the tires at the front axle of the vehicle are outside the tire centers, and the tire force points of the tires at the rear axle of the vehicle are inside the tire centers, and when the target sub-differential steering mode is the second sub-differential steering mode, the parameter adjustment unit 53 is further configured to: determine a target reverse yaw moment corresponding to the vehicle speed and the steering wheel angle based on a preset reverse yaw moment correspondence relationship, the preset reverse yaw moment correspondence relationship indicating a correspondence relationship among the vehicle speed, the steering wheel angle, and the reverse yaw moment, the direction of the reverse yaw moment being opposite to the current steering direction of the vehicle; determine a front axle basic yaw moment as a difference between the steering yaw moment and the target reverse yaw moment; perform wheel speed difference analysis on the front axle left and right wheels and the rear axle left and right wheels respectively according to the target yaw angular velocity to obtain a front axle target wheel speed difference and a rear axle target wheel speed difference; perform dynamics analysis on the front axle target wheel speed difference and an actual front axle wheel speed difference to obtain a front axle correction yaw moment, the actual front axle wheel speed difference being a measured front axle left and right wheel speed difference; perform dynamics analysis on the rear axle target wheel speed difference and an actual rear axle wheel speed difference to obtain a rear axle correction yaw moment, the actual rear axle wheel speed difference being a measured rear axle left and right wheel speed difference; obtain a front axle yaw control moment based on the front axle basic yaw moment and the front axle correction yaw moment; and obtain a rear axle yaw control moment based on the target reverse yaw moment and the rear axle correction yaw moment.

[0185] In some embodiments, the adjusted steering control parameter in the differential steering mode includes a front axle yaw control moment and a rear axle yaw control moment, and the steering control unit 54 is further configured to: obtain a first original torque, a second original torque, a third original torque and a fourth original torque, the first original torque being an original torque of a front axle left wheel motor, the second original torque being an original torque of a front axle right wheel motor, the third original torque being an original torque of a rear axle left wheel motor, and the fourth original torque being an original torque of a rear axle right wheel motor; correct the first original torque according to the front axle yaw control moment, a front axle left wheel tire radius, a front axle track and a front axle steering angle to obtain a first target torque; correct the second original torque according to the front axle yaw control moment, a front axle right wheel tire radius, the front axle track and the front axle steering angle to obtain a second target torque; correct the third original torque according to the rear axle yaw control moment, a rear axle left wheel tire radius and a rear axle track to obtain a third target torque; correct the fourth original torque according to the rear axle yaw control moment, a rear axle right wheel tire radius and the rear axle track to obtain a fourth target torque; and control the vehicle to perform a steering operation based on the first target torque, the second target torque, the third target torque and the fourth target torque.

[0186] In some embodiments, the drift steering mode includes a plurality of sub-drift steering modes, and different sub-drift steering modes correspond to different directional relationships between a first target moment and a second target moment, the first target moment being a driven yaw moment of a rear axle of the vehicle, and the second target moment being an inertial moment of the vehicle. In the case where the target steering mode is the drift steering mode, the parameter adjustment unit 53 is further configured to: determine, from the plurality of sub-drift steering modes, a target sub-drift steering mode that matches a directional relationship between the first target moment and the second target moment of the vehicle; and adjust the steering control parameter based on the target sub-drift steering mode.

[0187] In some embodiments, the steering control parameters in the drift turning mode include a front axle yaw control moment and a rear axle control wheel speed, and the parameter adjustment unit 53 is further configured to: correct an original yaw angular velocity of the vehicle to obtain a target yaw angular velocity based on a vehicle speed and a steering wheel angle, the original yaw angular velocity being a yaw angular velocity calculated based on a vehicle kinematics model; obtain a respective basic wheel speed of the left and right rear axle wheels according to the vehicle speed, the steering wheel angle, the target yaw angular velocity, and a corresponding rear axle wheel track of the vehicle; obtain a rear axle corrected wheel speed through wheel speed analysis based on the target yaw angular velocity and an actual yaw angular velocity of the vehicle, the actual yaw angular velocity being a measured yaw angular velocity; determine a respective target control wheel speed of the left and right rear axle wheels based on the respective basic wheel speed of the left and right rear axle wheels, the rear axle corrected wheel speed, and the steering wheel angle, the respective target control wheel speed of the left and right rear axle wheels belonging to the rear axle control wheel speed; determine a target yaw feedforward moment corresponding to the vehicle speed and the steering wheel angle based on a preset yaw feedforward moment corresponding relationship, the preset yaw feedforward moment corresponding relationship indicating a corresponding relationship among the vehicle speed, the steering wheel angle, and the yaw feedforward moment; obtain a target yaw feedback moment through moment analysis based on the target yaw angular velocity and the actual yaw angular velocity of the vehicle, the actual yaw angular velocity being a measured yaw angular velocity; obtain a steering yaw moment based on the target yaw feedforward moment and the target yaw feedback moment; obtain a front axle target wheel speed difference through wheel speed difference analysis of the left and right front axle wheels based on the target yaw angular velocity; obtain a front axle corrected yaw moment through dynamics analysis of the front axle target wheel speed difference and a front axle actual wheel speed difference, the front axle actual wheel speed difference being a measured front axle wheel speed difference; and obtain the front axle yaw control moment in the target sub-drift turning mode based on the steering yaw moment and the front axle corrected yaw moment.

[0188] In some embodiments, the parameter adjustment unit 53 is further configured to: determine a first target slip ratio corresponding to the vehicle speed and the steering wheel angle based on a first preset slip ratio corresponding relationship, the first preset slip ratio corresponding relationship indicating a corresponding relationship among the vehicle speed, the steering wheel angle, and a rear axle left wheel calibration slip ratio in the target sub-drift turning mode; determine a second target slip ratio corresponding to the vehicle speed and the steering wheel angle based on a second preset slip ratio corresponding relationship, the second preset slip ratio corresponding relationship indicating a corresponding relationship among the vehicle speed, the steering wheel angle, and a rear axle right wheel calibration slip ratio in the target sub-drift turning mode; obtain a first basic speed based on the vehicle speed, the first target slip ratio, the target yaw angular velocity, and the corresponding rear axle wheel track of the vehicle, the first basic speed being the basic wheel speed corresponding to the rear axle left wheel; obtain a second basic speed based on the vehicle speed, the second target slip ratio, the target yaw angular velocity, and the corresponding rear axle wheel track of the vehicle, the second basic speed being the basic wheel speed corresponding to the rear axle right wheel; In some embodiments, the parameter adjustment unit 53 is further configured to: determine a sign bit corresponding to the rear axle correction wheel speed according to the steering wheel angle; and obtain a target control wheel speed corresponding to each of the left and right rear wheels according to the basic wheel speed corresponding to each of the left and right rear wheels, the rear axle correction wheel speed, and the sign bit.

[0189] In some embodiments, the sub-drift mode includes a first sub-drift mode, the first sub-drift mode corresponds to a first target torque and a second target torque in the same direction, and when the target sub-drift mode is the first sub-drift mode, the parameter adjustment unit 53 is further configured to: determine the sum of the steering yaw moment and the front axle correction yaw moment as the front axle yaw control moment.

[0190] In some embodiments, the sub-drift mode includes a second sub-drift mode, the second sub-drift mode corresponds to a first target torque and a second target torque in opposite directions, and when the target sub-drift mode is the second sub-drift mode, the parameter adjustment unit 53 is further configured to: perform lateral acceleration analysis according to the vehicle speed and the target yaw rate to obtain an original lateral acceleration; determine a target yaw compensation coefficient corresponding to a lateral acceleration difference and the vehicle speed based on a preset yaw compensation coefficient corresponding relationship, the lateral acceleration difference being a difference between the original lateral acceleration and an actual lateral acceleration, the actual lateral acceleration being a measured lateral acceleration of the vehicle; determine a rear axle yaw moment based on the torque corresponding to each of the left and right rear wheels, the rear axle track, and the tire rolling radius; determine a front axle compensation yaw moment according to the target yaw compensation coefficient and the rear axle yaw moment; and obtain the front axle yaw control moment according to the steering yaw moment, the front axle correction yaw moment, and the front axle compensation yaw moment.

[0191] In some embodiments, the adjusted steering control parameters in the drift steering mode include a front axle yaw control moment and target control wheel speeds corresponding to the left and right rear wheels, and the steering control unit 54 is further configured to: obtain a first original torque and a second original torque, the first original torque being an original torque of the front axle left wheel motor and the second original torque being an original torque of the front axle right wheel motor; correct the first original torque according to the front axle yaw control moment, a front axle left wheel tire radius, a front axle track and a front axle steering angle to obtain a first target torque; correct the second original torque according to the front axle yaw control moment, a front axle right wheel tire radius, the front axle track and the front axle steering angle to obtain a second target torque; obtain a first target speed according to the target control wheel speed corresponding to the left rear wheel, a rear axle transmission ratio and a rear axle left wheel tire radius, the first target speed being a target speed of the left rear wheel; obtain a second target speed according to the target control wheel speed corresponding to the right rear wheel, the rear axle transmission ratio and a rear axle right wheel tire radius, the second target speed being a target speed of the right rear wheel; and control the vehicle to perform a steering operation based on the first target torque, the second target torque, the first target speed and the second target speed.

[0192] Based on the same application concept as the foregoing embodiments, the embodiments of the present application provide a vehicle steering control device, Figure 6 As shown in the structural diagram of the vehicle steering control device provided by the embodiments of the present application, Figure 6 The vehicle steering control device 6 provided by the embodiments of the present application can include a processor 60, a memory 61, a communication interface 62 and a bus 63 for connecting the processor 60, the memory 61 and the communication interface 62.

[0193] In the embodiments of the present application, the memory 61 is configured to store a computer program capable of running on the processor; The processor 60 is configured to, when running the computer program, obtain driving intention information, determine a target steering mode matching the driving intention information from a plurality of preset steering modes of the vehicle, wherein the plurality of preset steering modes at least include a differential steering mode and a drift steering mode, adjust steering control parameters of the vehicle based on the target steering mode, and control the vehicle to perform a steering operation based on the adjusted steering control parameters.

[0194] The embodiment of the present application provides a vehicle steering control device and equipment, obtain driving intention information; from a plurality of preset steering modes of the vehicle, determine a target steering mode matched with the driving intention information; wherein, the plurality of preset steering modes at least include a differential steering mode and a drift steering mode; based on the target steering mode, adjust the steering control parameter of the vehicle; based on the adjusted steering control parameter, control the vehicle to perform a steering operation. It can be seen that, in the present application, by setting the plurality of preset steering modes including the differential steering mode and the drift steering mode, and matching the corresponding target steering mode from the plurality of preset steering modes according to the driving intention information, the steering mode of the vehicle can be adapted to the differential steering demand or the drift steering demand pointed by the current steering working condition; by adjusting the steering control parameter based on the target steering mode, and controlling the vehicle to perform the steering operation based on the adjusted steering control parameter, different types of steering control can be more accurate, so that the steering radius can be adaptively reduced under different steering types.

[0195] The present application also provides a computer program product, including computer programs or instructions, which are executed by a processor to realize some or all steps of the above method. The computer program product can be specifically realized by hardware, software or a combination thereof. The computer program product can be specifically realized by hardware, software or a combination thereof. In an optional embodiment, the computer program product is specifically embodied as a computer storage medium, and in another optional embodiment, the computer program product is specifically embodied as a software product, such as a software development kit (Software Development Kit, SDK) and the like.

[0196] In addition, each functional module in the embodiment can be integrated in one processing unit, or each unit can exist physically independently, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional module.

[0197] If the integrated unit is implemented in the form of a software function module and is not sold or used as an independent product, it can be stored in a computer readable storage medium based on such understanding. The technical solutions of the embodiments essentially or the parts that contribute to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor to execute all or part of the steps of the embodiments. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various program code storage media.

[0198] The embodiment of the application provides a computer readable storage medium, which stores a program. The program is executed by a processor to implement the vehicle steering control method.

[0199] Specifically, the program instructions corresponding to the vehicle steering control method in the embodiment can be stored on a storage medium such as an optical disc, a hard disk, a U disk, etc. When the program instructions corresponding to the vehicle steering control method in the storage medium are read by an electronic device or executed, the following steps are included: obtaining driving intention information; determining a target steering mode matched with the driving intention information from a plurality of preset steering modes of the vehicle; wherein the plurality of preset steering modes at least include a differential steering mode and a drift steering mode; adjusting a steering control parameter of the vehicle based on the target steering mode; and controlling the vehicle to perform a steering operation based on the adjusted steering control parameter.

[0200] Those skilled in the art should understand that the embodiments of the application can be provided as a method, a system, or a computer program product. Therefore, the application can be in the form of a hardware embodiment, a software embodiment, or an embodiment combining software and hardware aspects. Moreover, the application can be in the form of a computer program product implemented on one or more computer usable storage media (including but not limited to magnetic disk storage and optical storage, etc.) containing computer usable program code.

[0201] The present application is described with reference to the accompanying drawings, which show implementation flow diagrams and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present application. It is understood that each flow and / or block in the flow diagrams and / or block diagrams, and combinations of flows and / or blocks in the flow diagrams and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing device, create means for implementing the functions specified in the flow diagrams and / or block diagrams. Figure 1 one or more flows and / or blocks. Figure 1 one or more flows and / or blocks.

[0202] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including an instruction device that implements the functions specified in the flow diagrams and / or block diagrams. Figure 1 one or more flows and / or blocks. Figure 1 one or more flows and / or blocks.

[0203] These computer program instructions can also be loaded onto a computer or other programmable data processing device to cause a series of operational steps to be performed on the computer or other programmable device to produce a computer implemented process such that the instructions that execute on the computer or other programmable device provide steps for implementing the functions specified in the flow diagrams and / or block diagrams. Figure 1 one or more flows and / or blocks. Figure 1 one or more flows and / or blocks.

[0204] The above embodiments are only preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Any equivalent replacement or transformation made by those skilled in the art based on the present application is within the protection scope of the present application.

Claims

1. A vehicle steering control method, characterized in that, The method includes: Obtain driving intent information; From a plurality of preset steering modes of the vehicle, a target steering mode that matches the driving intention information is determined; wherein the plurality of preset steering modes include at least a differential steering mode and a drift steering mode; Based on the target steering pattern, adjust the vehicle's steering control parameters; Based on the adjusted steering control parameters, the vehicle is controlled to perform steering operations.

2. The method according to claim 1, characterized in that, The differential steering mode includes multiple sub-differential steering modes, and different sub-differential steering modes correspond to different vehicle suspension states; When the target steering mode is the differential steering mode, adjusting the vehicle's steering control parameters based on the target steering mode includes: From the plurality of sub-differential steering modes, a target sub-differential steering mode that matches the vehicle suspension state of the vehicle is determined; Based on the target sub-differential steering mode, the steering control parameters are adjusted.

3. The method according to claim 2, characterized in that, The steering control parameters in the differential steering mode include the front axle yaw control torque and the rear axle yaw control torque. Adjusting the steering control parameters based on the target sub-differential steering mode includes: Based on the vehicle speed and steering wheel angle, the original yaw rate of the vehicle is corrected to obtain the target yaw rate. The original yaw rate is the yaw rate calculated based on the vehicle kinematics model. Based on the preset yaw feedforward torque correspondence, the target yaw feedforward torque corresponding to the vehicle speed and the steering wheel angle is determined. The preset yaw feedforward torque correspondence indicates the correspondence between vehicle speed, steering wheel angle and yaw feedforward torque. Torque analysis is performed based on the target yaw rate and the actual yaw rate of the vehicle to obtain the target yaw feedback torque, wherein the actual yaw rate is the measured yaw rate. The steering yaw moment is obtained based on the target yaw feedforward moment and the target yaw feedback moment; Based on the vehicle speed, the steering wheel angle, the target yaw rate, and the steering yaw torque, the front axle yaw control torque and the rear axle yaw control torque in the target sub-differential steering mode are determined.

4. The method according to claim 3, characterized in that, The sub-differential steering mode includes a first sub-differential steering mode. The vehicle suspension state indicator corresponding to the first sub-differential steering mode shows that the tire stress point of the front axle tires is outside the tire center, and the tire stress point of the rear axle tires is also outside the tire center. When the target sub-differential steering mode is the first sub-differential steering mode, determining the front axle yaw control torque and the rear axle yaw control torque under the target sub-differential steering mode based on the vehicle speed, the steering wheel angle, the target yaw rate, and the steering yaw torque includes: Based on the preset yaw moment distribution coefficient correspondence, the target yaw moment distribution coefficient corresponding to the vehicle speed and the steering wheel angle is determined. The preset yaw moment distribution coefficient correspondence indicates the correspondence between vehicle speed, steering wheel angle and yaw moment distribution coefficient. Based on the target yaw moment distribution coefficient and the steering yaw moment, the yaw moment is distributed between the front and rear axles of the vehicle to obtain the yaw moment distributed between the front axle and the yaw moment distributed between the rear axle. Based on the target yaw rate, wheel speed difference analysis is performed on the left and right wheels of the front axle and the left and right wheels of the rear axle to obtain the target wheel speed difference of the front axle and the target wheel speed difference of the rear axle. A dynamic analysis was performed on the target wheel speed difference and the actual wheel speed difference of the front axle to obtain the corrected yaw moment of the front axle. The actual wheel speed difference of the front axle is the measured wheel speed difference between the left and right wheels of the front axle. A dynamic analysis was performed on the target wheel speed difference and the actual wheel speed difference of the rear axle to obtain the corrected yaw moment of the rear axle. The actual wheel speed difference of the rear axle is the measured wheel speed difference between the left and right wheels of the rear axle. The front axle yaw control torque is obtained based on the front axle distributed yaw torque and the front axle corrected yaw torque. The rear axle yaw control torque is obtained based on the rear axle distributed yaw torque and the rear axle corrected yaw torque.

5. The method according to claim 3, characterized in that, The sub-differential steering mode includes a second sub-differential steering mode. The vehicle suspension state indicator corresponding to the second sub-differential steering mode shows that the tire stress point of the front axle tires is outside the tire center, and the tire stress point of the rear axle tires is inside the tire center. When the target sub-differential steering mode is the second sub-differential steering mode, determining the front axle yaw control torque and the rear axle yaw control torque under the target sub-differential steering mode based on the vehicle speed, the steering wheel angle, the target yaw rate, and the steering yaw torque includes: Based on a preset anti-yaw moment correspondence, the target anti-yaw moment corresponding to the vehicle speed and the steering wheel angle is determined. The preset anti-yaw moment correspondence indicates the correspondence between vehicle speed, steering wheel angle and anti-yaw moment. The direction of the anti-yaw moment is opposite to the current steering direction of the vehicle. The difference between the steering yaw moment and the target reverse yaw moment is determined as the front axle base yaw moment. Based on the target yaw rate, wheel speed difference analysis is performed on the left and right wheels of the front axle and the left and right wheels of the rear axle to obtain the target wheel speed difference of the front axle and the target wheel speed difference of the rear axle. A dynamic analysis was performed on the target wheel speed difference and the actual wheel speed difference of the front axle to obtain the corrected yaw moment of the front axle. The actual wheel speed difference of the front axle is the measured wheel speed difference between the left and right wheels of the front axle. A dynamic analysis was performed on the target wheel speed difference and the actual wheel speed difference of the rear axle to obtain the corrected yaw moment of the rear axle. The actual wheel speed difference of the rear axle is the measured wheel speed difference between the left and right wheels of the rear axle. The front axle yaw control torque is obtained based on the front axle base yaw moment and the front axle modified yaw moment. The rear axle yaw control torque is obtained based on the target reverse yaw moment and the rear axle corrected yaw moment.

6. The method according to claim 1, characterized in that, The drift steering mode includes multiple sub-drift steering modes. The directional relationship between the first target torque and the second target torque corresponding to different sub-drift steering modes is different. The first target torque is the active yaw torque of the rear axle of the vehicle, and the second target torque is the inertial torque of the vehicle. When the target steering mode is the drift steering mode, adjusting the vehicle's steering control parameters based on the target steering mode includes: From the plurality of sub-drift steering patterns, a target sub-drift steering pattern is determined that matches the directional relationship between the first target torque and the second target torque of the vehicle; The steering control parameters are adjusted based on the target sub-drift steering pattern.

7. The method according to claim 6, characterized in that, The steering control parameters in the drift steering mode include front axle yaw control torque and rear axle wheel speed control. Adjusting the steering control parameters based on the target sub-drift steering mode includes: Based on the vehicle speed and steering wheel angle, the original yaw rate of the vehicle is corrected to obtain the target yaw rate. The original yaw rate is the yaw rate calculated based on the vehicle kinematics model. Based on the vehicle speed, the steering wheel angle, the target yaw rate, and the rear axle track of the vehicle, the basic wheel speeds corresponding to the left and right rear wheels are obtained; Wheel speed analysis is performed based on the target yaw rate and the actual yaw rate of the vehicle to obtain the rear axle corrected wheel speed. The actual yaw rate is the measured yaw rate. Based on the base wheel speeds of the left and right rear wheels, the corrected wheel speeds of the rear axle, and the steering wheel angle, the target control wheel speeds of the left and right rear wheels are determined, and the target control wheel speeds of the left and right rear wheels are considered rear axle control wheel speeds. Based on the preset yaw feedforward torque correspondence, the target yaw feedforward torque corresponding to the vehicle speed and the steering wheel angle is determined. The preset yaw feedforward torque correspondence indicates the correspondence between vehicle speed, steering wheel angle and yaw feedforward torque. Torque analysis is performed based on the target yaw rate and the actual yaw rate of the vehicle to obtain the target yaw feedback torque, wherein the actual yaw rate is the measured yaw rate. The steering yaw moment is obtained based on the target yaw feedforward moment and the target yaw feedback moment; Based on the target yaw rate, the wheel speed difference between the left and right front axles is analyzed to obtain the target wheel speed difference of the front axle. A dynamic analysis was performed on the target wheel speed difference and the actual wheel speed difference of the front axle to obtain the corrected yaw moment of the front axle. The actual wheel speed difference of the front axle is the measured wheel speed difference between the left and right wheels of the front axle. Based on the steering yaw moment and the front axle correction yaw moment, the front axle yaw control moment in the target sub-drift steering mode is obtained.

8. The method according to claim 7, characterized in that, The step of obtaining the basic wheel speeds corresponding to the left and right rear wheels based on the vehicle speed, the steering wheel angle, the target yaw rate, and the vehicle's corresponding rear axle track includes: Based on the first preset slip ratio correspondence, a first target slip ratio corresponding to the vehicle speed and the steering wheel angle is determined. The first preset slip ratio correspondence indicates the correspondence between the vehicle speed, steering wheel angle and the calibrated slip ratio of the rear axle left wheel in the target sub-drift steering mode. Based on the second preset slip ratio correspondence, a second target slip ratio corresponding to the vehicle speed and the steering wheel angle is determined. The second preset slip ratio correspondence indicates the correspondence between the vehicle speed, steering wheel angle and the calibrated slip ratio of the right rear wheel in the target sub-drift steering mode. The first base speed is obtained based on the vehicle speed, the first target slip ratio, the target yaw rate, and the rear axle track of the vehicle. The first base speed is the base wheel speed corresponding to the left rear wheel. The second base speed is obtained based on the vehicle speed, the second target slip ratio, the target yaw rate, and the rear axle track of the vehicle. The second base speed is the base wheel speed corresponding to the right wheel of the rear axle.

9. The method according to claim 7, characterized in that, The sub-drift steering mode includes a first sub-drift steering mode, where the directional relationship corresponding to the first sub-drift steering mode is that the first target torque and the second target torque are in the same direction. When the target sub-drift steering mode is the first sub-drift steering mode, obtaining the front axle yaw control torque under the target sub-drift steering mode based on the steering yaw torque and the front axle correction yaw torque includes: The sum of the steering yaw moment and the front axle correction yaw moment is determined as the front axle yaw control moment.

10. The method according to claim 7, characterized in that, The sub-drift steering mode includes a second sub-drift steering mode, and the directional relationship corresponding to the second sub-drift steering mode is that the first target torque and the second target torque are in opposite directions. When the target sub-drift steering mode is the second sub-drift steering mode, obtaining the front axle yaw control torque under the target sub-drift steering mode based on the steering yaw torque and the front axle correction yaw torque includes: Lateral acceleration analysis is performed based on the vehicle speed and the target yaw rate to obtain the original lateral acceleration; Based on the preset yaw compensation coefficient correspondence, a target yaw compensation coefficient corresponding to the lateral acceleration difference and the vehicle speed is determined. The lateral acceleration difference is the difference between the original lateral acceleration and the actual lateral acceleration. The actual lateral acceleration is the measured lateral acceleration of the vehicle. The rear axle yaw moment is determined based on the torque of the left and right wheels of the rear axle, the rear axle track width, and the tire rolling radius. The front axle yaw compensation torque is determined based on the target yaw compensation coefficient and the rear axle yaw moment. The front axle yaw control torque is obtained based on the steering yaw moment, the front axle correcting yaw moment, and the front axle compensating yaw moment.

11. The method according to claim 1, characterized in that, The adjusted steering control parameters in the drift steering mode include the front axle yaw control torque and the target control wheel speeds for the left and right rear axles, respectively. Controlling the vehicle to perform steering operations based on these adjusted steering control parameters includes: Obtain a first original torque and a second original torque, wherein the first original torque is the original torque of the front axle left wheel motor and the second original torque is the original torque of the front axle right wheel motor; Based on the front axle yaw control torque, the radius of the left front wheel tire, the front axle track width, and the front axle steering angle, the first original torque is corrected to obtain the first target torque; Based on the front axle yaw control torque, the radius of the right front wheel tire, the front axle track width, and the front axle steering angle, the second original torque is corrected to obtain the second target torque; Based on the target control wheel speed corresponding to the left rear wheel, the rear axle transmission ratio, and the tire radius of the left rear wheel, the first target speed is obtained, which is the target speed of the left rear wheel; Based on the target control wheel speed corresponding to the right rear wheel, the rear axle transmission ratio, and the tire radius of the right rear wheel, the second target speed is obtained, which is the target speed of the right rear wheel. Based on the first target torque, the second target torque, the first target speed, and the second target speed, the vehicle is controlled to perform steering operations.

12. A vehicle steering control device, characterized in that, The vehicle steering control device includes: The intent acquisition unit is used to acquire driving intent information; A mode determination unit is used to determine a target steering mode that matches the driving intention information from a plurality of preset steering modes of the vehicle; wherein the plurality of preset steering modes include at least a differential steering mode and a drift steering mode; A parameter adjustment unit is used to adjust the steering control parameters of the vehicle based on the target steering mode. A steering control unit is used to control the vehicle to perform steering operations based on adjusted steering control parameters.

13. A vehicle steering control device, characterized in that, The vehicle steering control device includes a processor and a storage medium storing executable instructions. The storage medium performs operations via a communication bus dependent on the processor. When the executable instructions are executed by the processor, the vehicle steering control method according to any one of claims 1 to 11 is executed.

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