Turning auxiliary control method and device of vehicle, vehicle and storage medium

Abstract

The invention relates to the technical field of new energy vehicles, and particularly discloses a turning auxiliary control method and device of a vehicle, the vehicle and a storage medium, and the method comprises the steps that under the condition that a turning auxiliary mode is started, first state information of the vehicle is obtained, and whether the turning auxiliary mode is activated or not is judged based on the first state information; if yes, control information is generated to control a brake to brake and lock rear wheels on the outer side, and target turning speed information and steering wheel turning angle information are obtained; determining front and rear axle target torque information of the vehicle based on the target turning speed information and the steering wheel angle information; the target torque information of the front and rear shafts is corrected according to the yaw velocity and then fed back to front and rear electric drive assemblies of the vehicle to achieve vehicle turning auxiliary control; the second state information of the vehicle is obtained every second time, whether the turning auxiliary mode is quitted or not is judged based on the second state information, the turning radius is smaller, the stability of the vehicle in the turning process is better, and meanwhile the method can adapt to different road conditions.

Description

Technical Field

[0001] The present application relates to the technical field of new energy vehicles, and in particular to a vehicle turning assistance control method, device, vehicle and storage medium. Background Art

[0002] As an indispensable means of transportation in people's daily lives, cars will inevitably encounter scenarios where they need to turn around during driving. Especially in environments with limited space, such as crowded parking lots, narrow rural roads, or jungle crossings, reducing the car's turning radius can not only significantly improve the convenience of turning and turning operations, but also improve driving safety and reduce the risk of collision with other vehicles or obstacles, thereby providing drivers with a smoother and more efficient driving experience.

[0003] In the related art, the turning control method controls one pair of diagonal wheels to rotate in opposite directions while controlling the other pair of diagonal wheels not to rotate, so as to reduce the turning radius of the car. However, the ground friction of the locked diagonal wheels needs to be overcome by the ground adhesion of the unlocked diagonal wheels. When implemented on medium and high adhesion ground, there is a problem that the wheels are difficult to rotate; and when the vehicle turns, the target torque of the drive motor corresponding to the inner wheel is the feedback torque and the target torque of the drive motor corresponding to the outer wheel is the drive torque, so that the turning function of turning around in place can be achieved without changing the turning structure. However, this method is only applicable to vehicles with independent drive motors on the two rear wheels, or vehicles with independent drive motors on both the two front wheels and the two rear wheels. It cannot be applied to vehicles with only one motor driving the front and rear axles respectively. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a vehicle turning auxiliary control method, device, vehicle and storage medium.

[0005] In a first aspect, an embodiment of the present application provides a vehicle turning assistance control method, comprising: In response to a start instruction of a turning assist mode, obtaining first state information of the vehicle at first intervals; Determining whether to activate a turning assist mode based on the first state information; If activated, control information is generated to control the brake to lock the outer rear wheel, and obtain target turning speed information and steering wheel angle information; Determining target torque information of front and rear axles of the vehicle based on the target turning speed information and the steering wheel angle information; After correcting the front and rear axle target torque information, the information is fed back to the front and rear electric drive assemblies of the vehicle to implement vehicle turning assist control; When the vehicle executes the turning assist control strategy, second state information of the vehicle is obtained at second intervals, and whether to exit the turning assist mode is determined based on the second state information.

[0006] In some possible embodiments, the determining whether to activate the turn assist mode based on the first state information includes: The first state information includes current steering wheel angle, vehicle body state and gear position information; If the vehicle simultaneously satisfies: the current steering wheel angle is greater than or equal to a preset angle threshold, the vehicle body is in a stationary state, and the gear information is in a forward gear, then the turning assist mode is activated.

[0007] In some possible embodiments, if activated, generating control information to control the brake to lock the outer rear wheel and obtain target turning speed information and steering wheel angle information includes: Acquiring a current accelerator pedal opening of the vehicle, and determining the target turning speed information based on the accelerator pedal opening; Based on the target turning speed information and the steering wheel angle information, a front wheel target speed, a rear wheel target speed and a vehicle body target yaw angular velocity of the vehicle are obtained.

[0008] In some possible embodiments, obtaining the front wheel target speed, rear wheel target speed and vehicle body target yaw rate of the vehicle based on the target turning speed information and the steering wheel angle information includes: The calculation expression of the target turning speed is: v_drvReq=MAP1(k_Acc); The calculation expression of the front wheel target speed is: nf_tagt= f(v_drvReq, θ); The calculation expression of the rear wheel target speed is: nr_tagt=f(v_drvReq, θ); The calculation expression of the vehicle body target yaw angular velocity is: δ_drvReq =MAP2(v_drvReq, θ); Where v_drvReq is the target turning speed, k_Acc is the current accelerator pedal opening of the vehicle, and θ is the steering wheel angle.

[0009] In some possible embodiments, determining the target torque information of the front and rear axles of the vehicle based on the target turning speed information and the steering wheel angle information includes: According to the front wheel target speed and the rear wheel target speed, the front axle target torque information and the rear axle target torque information are determined respectively, wherein: The calculation expression of the front axle target torque is: Tf_req1= PID1(nf_tagt, (n_fi+n_fo) / 2); The calculation expression of the rear axle target torque is: Tr_req2 = PID2 (nr_tagt, n_ri / 2); Where nf_tagt is the target wheel speed of the front wheel, nr_tagt is the target wheel speed of the rear wheel, (n_fi+n_fo) / 2 is the average value of the input variables, and n_ri / 2 is half of the input variables.

[0010] In some possible embodiments, the front and rear axle target torque information is corrected and fed back to the front and rear electric drive assemblies of the vehicle to implement vehicle turning assist control, including: Acquiring an actual center-of-mass vehicle speed, and determining a center-of-mass vehicle speed correction coefficient based on the current actual center-of-mass vehicle speed and a target turning speed; Acquiring a current yaw rate of the vehicle, and determining a yaw moment correction torque based on the current yaw rate and a target yaw rate of the vehicle body; Based on the yaw moment correction torque and the center of mass speed correction coefficient, the front and rear axle target torque information is corrected to obtain the front and rear electric drive assembly request torque, wherein: The calculation expression of the center of mass speed correction coefficient is: K_Vspd = PID3 (v_drvReq, v_act); The calculation expression of the front axle target torque correction is: Tf_ad1_req = Tf_req*K_Vspd; The calculation expression of the rear axle target torque correction is: Tr_ad1_req = Tr_req*K_Vspd; The calculation expression of the yaw moment correction torque is: ΔT=MAP3(δ_drvReq, δ); The calculation expression of the front electric drive assembly request torque is: Tf_ad2_req= Tf_ad1_req-ΔT; The calculation expression of the rear electric drive assembly request torque is: Tf_ad2_req=Tf_ad2_req-ΔT; Where K_Vspd is the correction coefficient of the vehicle speed at the center of mass, δ_drvReq is the target yaw rate of the vehicle body, δ is the current yaw rate of the vehicle body, ΔT is the yaw moment correction torque, and Tf_req1 and Tf_req2 are the target torques of the front and rear axles.

[0011] In some possible embodiments, when the vehicle executes the turning assist control strategy, obtaining second state information of the vehicle at second intervals, and determining whether to exit the turning assist mode based on the second state information include: The second state information includes actual steering wheel angle, brake pedal state, gear position information and current vehicle speed information; If the vehicle meets any of the following conditions: the actual steering wheel angle is less than the preset angle threshold, the brake pedal is in the depressed state, the gear information is switched to non-D gear, or the current vehicle speed information is greater than the preset vehicle speed threshold, then the turning assist mode is exited.

[0012] In a second aspect, an embodiment of the present application provides a turning assist control device for a vehicle, comprising: A first acquisition module is configured to acquire first state information of the vehicle at first intervals when the user turns on the turning assist mode, and determine whether to activate the turning assist mode based on the first state information; a brake module configured to generate control information to control the brake to lock the outer rear wheel when the vehicle turn assist mode is activated; A second acquisition module is configured to acquire target turning vehicle speed information and steering wheel angle information when the vehicle turning assist mode is activated; a determination module configured to determine target torque information of front and rear axles of the vehicle based on the target turning speed information and the steering wheel angle information; A correction module, configured to determine a yaw moment correction torque based on the current yaw angular velocity of the vehicle and the target yaw angular velocity of the vehicle body; an execution module, configured to correct the front and rear axle target torque information and feed it back to the front and rear electric drive assemblies of the vehicle to implement vehicle turning assist control; The third acquisition module is configured to acquire second state information of the vehicle at second intervals when the vehicle executes the turning assist control strategy, and determine whether to exit the turning assist mode based on the second state information.

[0013] In a third aspect, an embodiment of the present application provides a vehicle, including: processor; a memory for storing instructions executable by the processor; Wherein, the processor is configured to: The steps of implementing the vehicle turning assistance control method described in the first aspect embodiment above.

[0014] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium having computer program instructions stored thereon, characterized in that when the program instructions are executed by a processor, the steps of a vehicle turning assistance control method described in the embodiment of the first aspect are implemented.

[0015] Compared with the prior art, the technical solution provided by the embodiment of the present invention includes at least the following beneficial effects or advantages: 1) In the turning assist control method of the vehicle of the present application, when the turning assist mode is activated, the brake is controlled by the system to lock the outer rear wheel, and the front drive motor is controlled to rotate forward and the rear drive motor is controlled to rotate reversely during the turning process. At the same time, the driver can adjust the speed, and after converting the target vehicle speed information into target torque control information, the target torque of the front and rear axles is corrected in combination with the actual vehicle body yaw angular velocity and the target yaw angular velocity, so that the rotation center of the vehicle turns approaches the center of mass of the vehicle, the turning radius is reduced, the vehicle stability is better during the turning process, and it can adapt to different road conditions.

[0016] 2) In the turning assist control method of the vehicle of the present application, by utilizing a dual-motor four-wheel drive system with a motor on each front and rear axle, and the motor has the characteristic of being able to achieve torque direction conversion without relying on a mechanical transmission mechanism, the outer rear wheel is locked when the vehicle turns, and at the same time, the front and rear motors apply opposite torques to make the front wheel rotate forward and the inner rear wheel reverse, thereby generating a yaw moment that is beneficial to the rotation of the vehicle. This effectively increases the turning radius of the vehicle without increasing the system cost. During the vehicle's turning process, the vehicle's turning speed can be controlled by the accelerator pedal or a manual speed control device, thereby increasing the driver's confidence in vehicle control.

[0017] 3) When the front and rear motor torques are controlled, the target speeds of the front and rear axles are calculated based on the steering wheel angle and the target vehicle speed. The target vehicle speed and yaw rate are used as control targets to dynamically adjust the front and rear axle drive motor torques to achieve stable vehicle speeds and yaw rates when the vehicle turns, while avoiding the risk of vehicle instability caused by excessive yaw rates.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 is a schematic diagram of a front and rear dual-motor four-wheel drive vehicle according to an embodiment of the present application; Figure 2 is a flow chart of a vehicle turning assistance control method according to an embodiment of the present application; Figure 3is a schematic diagram of a turning assist control method for a front and rear dual-motor four-wheel drive vehicle according to an embodiment of the present application; Figure 4 is a data processing flow chart of a turning assistance control method for a vehicle according to an embodiment of the present application; Figure 5 is a block diagram of a turning assist control device for a vehicle according to an embodiment of the present invention; Figure 6 is another block diagram of a turning assist control device for a vehicle according to an embodiment of the present invention; Figure 7 is a functional block diagram of a vehicle according to an embodiment of the present invention. DETAILED DESCRIPTION

[0021] The embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0022] It should be noted that, unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0023] At present, there are different methods for steering control of automobiles for different models. In order to further reduce the turning radius of the vehicle and realize its application in more scenarios, the existing solutions for two-wheel drive vehicles and mechanical four-wheel drive vehicles mainly include 1) braking the inner rear wheel and 2) rear wheel follow-up steering.

[0024] For 1) braking the inner rear wheel, in an existing method, when the activation conditions of the assisted turning function are met, the vehicle is controlled to enter the activated state of the assisted turning function, and the hydraulic control unit is controlled to apply pressure to the inner rear wheel brake cylinder when the vehicle is turning, thereby reducing the turning radius of the vehicle to enable the vehicle to quickly turn and pass through a narrow space. In this solution, when the vehicle turns, the rotation axis of the yaw torque generated by the front and rear drive systems is outside the vehicle body, resulting in the vehicle's rotation radius still being greater than the distance between the inner rear wheel and the outer front wheel. This solution can reduce the turning radius to a certain extent, but its turning radius is still limited by the size of the vehicle and the characteristics of the steering system.

[0025] Regarding 2) rear wheel follow-up steering, the existing technology adds a follow-up steering mechanism to the rear wheel. When the front wheel steering is detected, the rear wheel follows and generates a turning angle in the opposite direction. However, the need to add a rear wheel steering mechanism will increase the cost, and the resulting turning radius reduction rate is equivalent to that of solution 1) braking the inner rear wheel.

[0026] For front and rear dual-motor four-wheel drive vehicles, the turning radius can be reduced to a certain extent based on 1) braking the inner rear wheel and 2) rear wheel follow-up steering. The turning radius reduction performance is comparable to that of traditional two-wheel drive vehicles and mechanical four-wheel drive vehicles. However, since the drive motor has the advantage of being able to freely control the torque direction without relying on the transmission mechanism, this advantage can be used to control the front wheel to rotate forward and the inner rear wheel to reverse when turning, generating a yaw torque to reduce the turning radius. In an existing technical solution, one pair of diagonal wheels is controlled to rotate in opposite directions, while the other pair of diagonal wheels is controlled not to rotate, so as to reduce the turning radius of the car. This solution requires the ground adhesion of the unlocked diagonal wheels to overcome the ground friction of the locked diagonal wheels. When implemented on medium and high adhesion ground, there is a problem that the wheels are difficult to rotate.

[0027] And for front and rear dual-motor four-wheel drive vehicles, in another steering scheme, when the vehicle is turning, the target torque of the drive motor corresponding to the inner wheel is the feedback torque and the target torque of the drive motor corresponding to the outer wheel is the drive torque, and the steering function of turning on the spot can be achieved without changing the steering structure. However, this scheme is only applicable to vehicles with independent drive motors configured for the two rear wheels, or vehicles with independent drive motors configured for both the two front wheels and the two rear wheels, and cannot be applied to vehicles with only one motor driving the front and rear axles respectively, which is the focus of the present invention.

[0028] Based on this, the inventor proposes a vehicle turning assist control method, device, vehicle and storage medium. In addition to being applied to front and rear dual-motor four-wheel drive vehicles, the method can also be applied to other vehicles equipped with independent front and rear axle drive and a power system with a rear axle having reversing capability (such as front axle engine drive, rear axle motor drive; front axle left and right dual-motor wheel hub / wheel side drive, rear axle single motor drive; front axle single motor drive, rear axle dual motor drive; front axle left and right dual-motor wheel hub / wheel side drive, rear axle left and right dual-motor wheel hub / wheel side drive); the method realizes that the rotation center of the vehicle turning is close to the vehicle's center of mass, reducing the turning radius, improving the vehicle stability during turning, and can adapt to different road conditions.

[0029] The following is a further description of the vehicle turning assistance control method of the present application in conjunction with a front and rear dual-motor four-wheel drive vehicle. Figure 1 and Figure 2The front and rear dual-motor four-wheel drive vehicle includes 1-front drive assembly, 2-rear drive assembly, 3-control system, 4-outer rear wheel, 5-outer front wheel, 6-inner front wheel, 7-inner rear wheel, 8-braking system, 9-vehicle speed adjustment device, 1-signal line: wherein, 1-front drive assembly can transmit power to 6-inner front wheel and 5-outer front wheel through the left and right half shafts of the front axle; 2-rear drive assembly can transmit power to 7-inner rear wheel and 4-outer rear wheel through the left and right half shafts of the rear axle; 3-control system communicates signals with 1-front drive assembly, 2-rear drive assembly, and 8-braking system through signal lines.

[0030] It should be noted that the following embodiments are based on a dual-motor four-wheel drive system with one motor on each front and rear axle, and the motor has the function of converting the torque direction independently of a mechanical transmission mechanism. When the vehicle turns, the outer rear wheel is locked, and at the same time, the front and rear motors apply opposite torques to cause the front wheel to rotate forward and the inner rear wheel to reverse, thereby generating a yaw moment that is beneficial to the rotation of the vehicle. This effectively increases the turning radius of the vehicle without increasing the system cost.

[0031] See also Figures 2 to 4 This embodiment provides a vehicle turning assistance control method, including: Step S10: in response to a start instruction of the turning assist mode, obtaining first state information of the vehicle at first intervals; In this step, it can be understood that the turning assist mode can be controlled by the in-vehicle entertainment system or by physical buttons, or the start of the turning assist mode can be automatically controlled by intelligent driving. It can be selectively set according to actual needs. Taking physical buttons for switch control as an example, the user turns on the turning assist mode by selecting the switch. After receiving the start command, it responds to the turning assist mode and collects the first state information of the current vehicle.

[0032] It should be noted that the first time can be 0.01ms, 0.1ms or 1ms. The specific time interval of the first time can be selectively set according to actual needs. Of course, for some sensors, the frequency of collecting information has been set at the factory, which will not be repeated here. The first state information includes the current steering wheel angle, vehicle body state and gear information, among which the current steering wheel angle information can be collected by the angle sensor. The vehicle body state in this embodiment is mainly a moving state and a stationary state. The gear information can be divided into forward gear and other gear states. The vehicle body state can be judged by the information collected by the speed sensor. The gear information can be directly read through the central control system of the vehicle. The first state information is used as a control condition for activating the turning assist mode.

[0033] Step S20: determining whether to activate the turning assist mode based on the first state information; In this step, after the turning assist mode is started, it is also necessary to determine whether to activate the turning assist mode. For example, if the first state information collected by the vehicle satisfies all the same conditions: the current steering wheel angle is greater than or equal to a preset turning angle threshold, the vehicle body is in a stationary state, and the gear information is in the forward gear, then the turning assist mode is activated; it should be noted that the preset turning angle threshold can be 540°-720°. Preferably, the steering wheel is turned to the stop. It can be set according to actual needs. Only when the turning assist mode is activated will the subsequent control steps be entered. When the first state information does not meet the above conditions at the same time, the vehicle will continue to collect corresponding information.

[0034] It can be understood that the activation of the turning assist mode in this step can be preferably used for the vehicle to turn forward at a large angle starting from a stationary state.

[0035] Step S30: if activated, generating control information to control the brake to lock the outer rear wheel, and obtaining target turning speed information and steering wheel angle information; In this step, when the turn assist mode is activated, control information is first generated to control the brake to lock the outer rear wheel. It can be understood that the corresponding control information can be generated by the ECU and transmitted to the brake of the outer rear wheel to achieve the braking and locking of the outer rear wheel. The ECU (the central controller of the car, also known as the electronic control unit) is the core component of the vehicle's electronic system, responsible for managing and coordinating various functions, such as engine control, body stability, safety system, etc. It collects data through sensors and processes information in real time. The specific information processing and transmission implementation principles are not elaborated here.

[0036] In one example, combining Figure 2 and Figure 3 As shown, for the acquisition of target turning speed information and steering wheel angle information, after the system corresponding to the turning assist mode detects that the user has released the brake pedal, the user can control the turning target speed through the speed regulating device; the speed regulating device can be an accelerator pedal or a manual speed regulating device, which is selectively set according to the relevant components of the actual vehicle. Taking the accelerator pedal as an example, the current accelerator pedal opening of the vehicle can be obtained, and the target turning speed information is determined based on the accelerator pedal opening. The determination process can be performed by looking up a preset mapping table to obtain the target turning speed information after collecting the accelerator pedal opening.

[0037] After the target turning speed information is obtained, the front wheel target speed, rear wheel target speed and vehicle body target yaw rate can be obtained in combination with the steering wheel angle information. It should be noted that the front wheel target speed, rear wheel target speed and vehicle body target yaw rate are obtained based on the target turning speed information and the steering wheel angle information. The specific calculation process includes: The calculation expression of the target turning speed is: v_drvReq=MAP1(k_Acc); The calculation expression of the front wheel target speed is: nf_tagt= f(v_drvReq, θ); The calculation expression of the rear wheel target speed is: nr_tagt=f(v_drvReq, θ); The calculation expression of the vehicle body target yaw angular velocity is: δ_drvReq =MAP2(v_drvReq, θ); Where v_drvReq is the target turning speed, k_Acc is the current accelerator pedal opening of the vehicle, and θ is the steering wheel angle.

[0038] In the existing large-angle turning control method, for example, when a large-angle U-turn is required, since the driving force direction of the original vehicle is not changed, the inner rear wheel is only braked to prevent it from rotating. The vehicle steering center is closer to the inner rear wheel than the Ackerman steering center of the original vehicle. Since no vertical yaw moment around the center of mass of the vehicle body is formed, the steering center of the vehicle is still outside the vehicle body, and the turning radius reduction performance is limited. At the same time, the problem of vehicle stability not being guaranteed if accelerated during large-angle turns is not solved. Therefore, the speed cannot be controlled during the turning process, that is, the driver cannot accelerate when turning, and can only rely on the preset speed of the vehicle to make a U-turn. In this step, the speed of the U-turn can be controlled by the accelerator pedal or the manual speed adjustment device during the vehicle turning process, thereby increasing the driver's control over the vehicle.

[0039] Step S40: determining target torque information of the front and rear axles of the vehicle based on the target turning speed information and the steering wheel angle information; In this step, in order to achieve accurate control of the wheel speed, the target torque information of the front and rear axles of the vehicle is determined based on the target turning speed information and the steering wheel angle information, including determining the front axle target torque information and the rear axle target torque information according to the front wheel target speed and the rear wheel target speed, respectively, wherein: The calculation expression of the front axle target torque is: Tf_req1= PID1(nf_tagt, (n_fi+n_fo) / 2); The calculation expression of the rear axle target torque is: Tr_req2 = PID2 (nr_tagt, n_ri / 2); Where nf_tagt is the target wheel speed of the front wheel, nr_tagt is the target wheel speed of the rear wheel, (n_fi+n_fo) / 2 is the average value of the input variables, and n_ri / 2 is half of the input variables.

[0040] It can be understood that the target turning speed information and steering wheel angle information are calculated and converted into control information of the front axle target torque and the rear axle target torque in the vehicle's central control processor through the above expressions. Of course, it can be understood that the target turning speed, front wheel target speed, rear wheel target speed and vehicle body target yaw angular velocity can be processed by setting up multiple PID modules.

[0041] Step S50: After correcting the front and rear axle target torque information, the information is fed back to the front and rear electric drive assemblies of the vehicle to implement vehicle turning assist control; In this step, before correcting the target torque information of the front and rear axles, the actual center-of-mass speed is obtained, and the center-of-mass speed correction coefficient is determined based on the current actual center-of-mass speed and the target turning speed; Acquiring a current yaw rate of the vehicle, and determining a yaw moment correction torque based on the current yaw rate and a target yaw rate of the vehicle body; Based on the yaw moment correction torque and the center of mass speed correction coefficient, the front and rear axle target torque information is corrected to obtain the front and rear electric drive assembly request torque, wherein: The calculation expression of the center of mass speed correction coefficient is: K_Vspd = PID3 (v_drvReq, v_act); The calculation expression of the front axle target torque correction is: Tf_ad1_req = Tf_req*K_Vspd; The calculation expression of the rear axle target torque correction is: Tr_ad1_req = Tr_req*K_Vspd; The calculation expression of the yaw moment correction torque is: ΔT=MAP3(δ_drvReq, δ); The calculation expression of the front electric drive assembly request torque is: Tf_ad2_req= Tf_ad1_req-ΔT; The calculation expression of the rear electric drive assembly request torque is: Tf_ad2_req=Tf_ad2_req-ΔT; Where K_Vspd is the correction coefficient of the vehicle speed at the center of mass, δ_drvReq is the target yaw rate of the vehicle body, δ is the current yaw rate of the vehicle body, ΔT is the yaw moment correction torque, and Tf_req1 and Tf_req2 are the target torques of the front and rear axles.

[0042] It should be noted that, during the correction process, the longitudinal vehicle speed Vy, the lateral vehicle speed Vx, the yaw angular velocity δ, and the actual wheel speed signals of each wheel can also be obtained through sensors: the inner front wheel speed n_fi, the outer front wheel speed n_fo, the inner rear wheel speed n_ri, and the outer rear wheel speed n_ro. Based on the actual outer front wheel speed n_fo and the actual inner rear wheel speed n_ri, the outer front wheel target speed, the inner front wheel target speed and the inner rear wheel target speed are corrected to achieve control accuracy, thereby ensuring that the radius of the vehicle is minimized when turning at a large angle.

[0043] It should also be noted that for the target maximum yaw rate, the corresponding mapping table can be checked by obtaining the actual vehicle speed of the center of mass to obtain the target maximum yaw rate, and the yaw correction torque can be obtained by checking the corresponding mapping table in combination with the target maximum yaw rate and the ESP yaw rate.

[0044] Step S60: When the vehicle executes the turning assist control strategy, second state information of the vehicle is obtained at second intervals, and whether to exit the turning assist mode is determined based on the second state information.

[0045] In this step, the second state information includes the actual steering wheel angle, brake pedal status, gear information and current vehicle speed information. If the vehicle meets any of the following conditions: the actual steering wheel angle is less than the preset angle threshold, the brake pedal status is in the pressed state, the gear information is switched to non-D gear or the current vehicle speed information is greater than the preset vehicle speed threshold, then the turning assist mode is exited.

[0046] It is understandable that the second time can be 0.01ms, 0.1ms or 1ms. When the second state information of the vehicle is obtained on the premise that the vehicle has executed the turning assist control strategy, the preset turning angle threshold can be 540°-720°, which can be selectively set according to actual needs. The brake pedal is in the depressed state, that is, the driver performs braking control. The preset vehicle speed threshold can be 10km / h, 20 km / h or 50km / h, which can be selectively set according to actual needs. As long as any one of the conditions is met, the central control system of the vehicle generates control information to exit the turning assist mode. It should be noted that in the turning assist control method steps of the vehicle of the present embodiment, when the turning assist mode is activated, the system controls the brake to lock the outer rear wheel, and the front drive motor is controlled to rotate forward and the rear drive motor is controlled to rotate reversely during the turning process. At the same time, the driver can adjust the speed, and after converting the target vehicle speed information into target torque control information, the target torque of the front and rear axles is corrected in combination with the actual vehicle body yaw angular velocity and the target yaw angular velocity, so that the rotation center of the vehicle turning is close to the vehicle's center of mass, the turning radius is reduced, the vehicle stability is better during the turning process, and it can adapt to different road conditions.

[0047] At the same time, by utilizing a dual-motor four-wheel drive system with a motor on each front and rear axle, and the motor has the characteristic of being able to achieve torque direction conversion without relying on a mechanical transmission mechanism, the outer rear wheel is locked when the vehicle turns, and at the same time the front and rear motors apply opposite torques to make the front wheel rotate forward and the inner rear wheel reverse, generating a yaw moment that is beneficial to the rotation of the vehicle. This effectively increases the turning radius of the vehicle without increasing the system cost. During the turning process, the vehicle's turning speed can be controlled by the accelerator pedal or the manual speed adjustment device, thereby increasing the driver's confidence in vehicle control.

[0048] In addition, when controlling the torque of the front and rear motors, the target speeds of the front and rear axles are calculated based on the steering wheel angle and the target vehicle speed. The target vehicle speed and yaw rate are used as control targets to dynamically adjust the torque of the front and rear axle drive motors to achieve stable vehicle speed and yaw rate when the vehicle turns, while avoiding the risk of vehicle instability caused by excessive yaw rate.

[0049] See also Figure 5 , Figure 5 A turning assist control device for a vehicle of the present application is shown, and the turning assist control device 200 for a vehicle includes: The first acquisition module 210 is configured to acquire first state information of the vehicle at first intervals when the user turns on the turning assist mode, and determine whether to activate the turning assist mode based on the first state information; The brake module 220 is configured to generate control information to control the brake to lock the outer rear wheel when the vehicle turning assist mode is activated; The second acquisition module 230 is configured to acquire target turning vehicle speed information and steering wheel angle information when the vehicle turning assist mode is activated; A determination module 240 is configured to determine target torque information of front and rear axles of the vehicle based on the target turning speed information and the steering wheel angle information; The correction module 250 is configured to determine the yaw moment correction torque based on the current yaw angular velocity of the vehicle and the target yaw angular velocity of the vehicle body; The execution module 260 is configured to correct the front and rear axle target torque information and feed it back to the front and rear electric drive assemblies of the vehicle to implement vehicle turning assist control; The third acquisition module 270 is configured to acquire second state information of the vehicle at second intervals when the vehicle executes the turning assist control strategy, and determine whether to exit the turning assist mode based on the second state information.

[0050] It should be noted that when the turning assist mode is activated, the modules of the turning assist control device 200 of the above-mentioned vehicle lock the outer rear wheel through the system control brake, control the front drive motor to rotate forward and control the rear drive motor to rotate reverse during the turning process, and the driver can adjust the speed at the same time. After converting the target vehicle speed information into target torque control information, the target torque of the front and rear axles is corrected in combination with the actual vehicle body yaw angular velocity and the target yaw angular velocity, so that the rotation center of the vehicle turning is close to the vehicle's center of mass, the turning radius is reduced, the vehicle stability is better during the turning process, and it can adapt to different road conditions.

[0051] The dual-motor four-wheel drive system has a motor on each front and rear axle, and the motor has the characteristic of being able to achieve torque direction conversion without relying on a mechanical transmission mechanism. When the vehicle turns, the outer rear wheel is locked, and at the same time, the front and rear motors apply opposite torques to make the front wheel rotate forward and the inner rear wheel reverse, generating a yaw moment that is beneficial to the rotation of the vehicle. This effectively increases the turning radius of the vehicle without increasing the system cost. During the turning process, the vehicle's turning speed can be controlled by the accelerator pedal or the manual speed adjustment device, increasing the driver's confidence in vehicle control.

[0052] See also Figure 6 In one example, the implementation process of the turning assist control device for a vehicle may further include: The vehicle state perception module C1 is configured to be responsible for obtaining the longitudinal vehicle speed Vy, the lateral vehicle speed Vx, the yaw angular velocity δ, and the wheel speed signals of each wheel through sensors: the inner front wheel speed n_fi, the outer front wheel speed n_fo, the inner rear wheel speed n_ri, and the outer rear wheel speed n_ro.

[0053] The vehicle target motion posture calculation module C2 is configured to first analyze the driver's turning speed demand v_drvReq according to the accelerator pedal opening k_Acc, and then calculate the front wheel target speed nf_tagt, the rear wheel target speed nr_tagt, and the vehicle body target yaw angular velocity δ_drvReq according to the target turning speed v_drvReq and the steering wheel angle θ; Among them, the calculation expression of the target turning speed is: v_drvReq=MAP1(k_Acc); The calculation expression of the front wheel target speed is: nf_tagt= f1(v_drvReq, θ); The calculation expression of the rear wheel target speed is: nr_tagt=f2(v_drvReq, θ); The calculation expression of the vehicle body target yaw angular velocity is: δ_drvReq =MAP2(v_drvReq, θ); Where v_drvReq is the target turning speed, k_Acc is the current accelerator pedal opening of the vehicle, and θ is the steering wheel angle.

[0054] The front and rear axle target torque calculation module C3 is configured to calculate the front axle target torque Tf_req and the rear axle target torque Tr_req respectively according to the front wheel target speed nf_tagt and the rear wheel target speed nr_tagt; The calculation expression of the front axle target torque is: Tf_req1= PID1(nf_tagt, (n_fi+n_fo) / 2); The calculation expression of the rear axle target torque is: Tr_req2 = PID2 (nr_tagt, n_ri / 2); Where nf_tagt is the target wheel speed of the front wheel, nr_tagt is the target wheel speed of the rear wheel, (n_fi+n_fo) / 2 is the average value of the input variables, and n_ri / 2 is half of the input variables.

[0055] The yaw moment correction module C4 is configured to calculate a yaw moment correction torque ΔT according to the target yaw angular velocity δ_drvReq calculated by the vehicle target motion posture calculation module C2 and the actual vehicle body yaw angular velocity δ obtained by the vehicle perception module C1 in order to achieve the stability of the target yaw angular velocity during the vehicle turning process, correct the front and rear axle target torques to obtain the corrected front and rear motor request torques Tf_ad_req and Tf_ad_req, and use them as output signals to request the front and rear motors to execute, wherein, The calculation expression of the yaw moment correction torque is: ΔT=MAP3(δ_drvReq, δ); The calculation expression of the front electric drive assembly request torque is: Tf_ad_req= Tf_req1-ΔT; The calculation expression of the rear electric drive assembly request torque is: Tf_ad_req= Tf_req2-ΔT; Where δ_drvReq is the target yaw rate of the vehicle body, δ is the current yaw rate of the vehicle body, ΔT is the yaw moment correction torque, and Tf_req1 and Tf_req2 are the target torques of the front and rear axles.

[0056] It is understandable that the technical effect achieved by the vehicle turning assist control device provided by this embodiment can be referred to in Figure 5 The technical effects achieved by the corresponding embodiments are not described in detail here.

[0057] See also Figure 7, this embodiment provides a vehicle, the vehicle 600 may include various subsystems, for example, an infotainment system 610, a perception system 620, a decision control system 630, a drive system 640, and a computing platform 650. Optionally, the vehicle 600 may include more or fewer subsystems, and each subsystem may include multiple components. In addition, each subsystem and component of the vehicle 600 may be interconnected by wire or wirelessly.

[0058] In some embodiments, infotainment system 610 may include communication system 611 , entertainment system 612 , and navigation system 613 .

[0059] The communication system 611 may include a wireless communication system that can communicate wirelessly with one or more devices directly or via a communication network. For example, the wireless communication system may use 3G cellular communication, such as CDMA, EVDO, GSM / GPRS, or 4G cellular communication, such as LTE. Or 5G cellular communication. The wireless communication system may communicate with a wireless local area network (WLAN) using WiFi. In some embodiments, the wireless communication system may communicate directly with the device using an infrared link, Bluetooth, or ZigBee. Other wireless protocols, such as various vehicle communication systems, for example, the wireless communication system may include one or more dedicated short range communications (DSRC) devices, which may include public and / or private data communications between vehicles and / or roadside stations.

[0060] The entertainment system 612 may include a display device, a microphone and speakers. Users can listen to the radio and play music in the car based on the entertainment system; or connect the mobile phone to the vehicle and project the mobile phone's screen on the display device. The display device may be touch-screen, and users can operate by touching the screen.

[0061] In some cases, the user's voice signal can be obtained through a microphone, and based on the analysis of the user's voice signal, the user can control certain aspects of the vehicle 600, such as adjusting the temperature inside the vehicle, etc. In other cases, music can be played to the user through a speaker.

[0062] The navigation system 613 may include a map service provided by a map provider, thereby providing navigation of the driving route for the vehicle 600. The navigation system 613 may be used in conjunction with the vehicle's global positioning system 621 and inertial measurement unit 622. The map service provided by the map provider may be a two-dimensional map or a high-precision map.

[0063] The perception system 620 may include several sensors that sense information about the environment around the vehicle 600. For example, the perception system 620 may include a global positioning system 621 (the global positioning system may be a GPS system, or a Beidou system or other positioning systems), an inertial measurement unit (IMU) 622, a laser radar 623, a millimeter wave radar 624, an ultrasonic radar 625, and a camera 626. The perception system 620 may also include sensors of the internal systems of the monitored vehicle 600 (for example, an in-vehicle air quality monitor, a fuel gauge, an oil temperature gauge, etc.). Sensor data from one or more of these sensors can be used to detect objects and their corresponding characteristics (position, shape, direction, speed, etc.). This detection and recognition is a key function for the safe operation of the vehicle 600.

[0064] The global positioning system 621 is used to estimate the geographic location of the vehicle 600 .

[0065] The inertial measurement unit 622 is used to sense the change of the posture of the vehicle 600 based on the inertial acceleration. In some embodiments, the inertial measurement unit 622 may be a combination of an accelerometer and a gyroscope.

[0066] Lidar 623 utilizes lasers to sense objects in the environment in which vehicle 600 is located. In some embodiments, Lidar 623 may include one or more laser sources, a laser scanner, and one or more detectors, among other system components.

[0067] The millimeter wave radar 624 uses radio signals to sense objects in the surrounding environment of the vehicle 600. In some embodiments, in addition to sensing objects, the millimeter wave radar 624 can also be used to sense the speed and / or heading of the object.

[0068] The ultrasonic radar 625 may sense objects around the vehicle 600 using ultrasonic signals.

[0069] The camera device 626 is used to capture image information of the surrounding environment of the vehicle 600. The camera device 626 may include a monocular camera, a binocular camera, a structured light camera, a panoramic camera, etc. The image information acquired by the camera device 626 may include a static image or video stream information.

[0070] The decision control system 630 includes a computing system 631 that analyzes and makes decisions based on the information obtained by the perception system 620. The decision control system 630 also includes a vehicle controller 632 that controls the power system of the vehicle 600, and a turning system 633, throttle 634 and braking system 635 for controlling the vehicle 600.

[0071] The computing system 631 can be operated to process and analyze various information obtained by the perception system 620 in order to identify targets, objects and / or features in the surrounding environment of the vehicle 600. Targets may include pedestrians or animals, and objects and / or features may include traffic signals, road boundaries and obstacles. The computing system 631 may use object recognition algorithms, Structure from Motion (SFM) algorithms, video tracking and other technologies. In some embodiments, the computing system 631 can be used to map the environment, track objects, estimate the speed of objects, and so on. The computing system 631 can analyze the various information obtained and derive a control strategy for the vehicle.

[0072] The vehicle controller 632 can be used to coordinate the control of the vehicle's power battery and engine 641 to improve the power performance of the vehicle 600.

[0073] Turning system 633 is operable to adjust the forward direction of vehicle 600. For example, in one embodiment, it may be a steering wheel system.

[0074] The throttle 634 is used to control the operating speed of the engine 641 and thereby control the speed of the vehicle 600 .

[0075] Braking system 635 is used to control the deceleration of vehicle 600. Braking system 635 can use friction to slow down wheel 644. In some embodiments, braking system 635 can convert the kinetic energy of wheel 644 into electric current. Braking system 635 can also take other forms to slow down the rotation speed of wheel 644 to control the speed of vehicle 600.

[0076] The drive system 640 may include components that provide powered movement for the vehicle 600. In one embodiment, the drive system 640 may include an engine 641, an energy source 642, a transmission system 643, and wheels 644. The engine 641 may be an electric motor or other types of engine combinations that convert the energy source 642 into mechanical energy.

[0077] Examples of energy source 642 include solar panels, batteries, and other sources of electricity. Energy source 642 can also provide energy for other systems of vehicle 600.

[0078] The transmission system 643 can transmit the mechanical power from the engine 641 to the wheels 644. In one embodiment, the transmission system 643 can also include other devices, such as a clutch. Among them, the drive shaft can include one or more shafts that can be coupled to one or more wheels 644.

[0079] Some or all functions of the vehicle 600 are controlled by a computing platform 650. The computing platform 650 may include at least one processor 651 that may execute instructions 653 stored in a non-transitory computer-readable medium such as a memory 652. In some embodiments, the computing platform 650 may also be a plurality of computing devices that control individual components or subsystems of the vehicle 600 in a distributed manner.

[0080] The processor 651 may be any conventional processor, such as a commercially available CPU. Alternatively, the processor 651 may also include a graphics processor (Graphic Process Unit, GPU), a field programmable gate array (Field Programmable Gate Array, FPGA), a system on chip (System on Chip, SOC), an application specific integrated circuit (Application Specific Integrated Circuit, ASIC) or a combination thereof. Figure 7 Functionally illustrated are processors, memories, and other elements of computers in the same block, but those of ordinary skill in the art will appreciate that the processor, computer, or storage may actually include multiple processors, computers, or memories that may or may not be stored in the same physical housing. For example, the memory may be a hard drive or other storage medium that is located in a housing different from the computer. Therefore, references to processors or computers will be understood to include references to a collection of processors or computers or memories that may or may not operate in parallel. Different from using a single processor to perform the steps described herein, some components such as a turning component and a deceleration component may each have their own processor that only performs calculations related to the functions specific to the component.

[0081] In the embodiment of the present disclosure, the processor 651 can execute the steps of the vehicle turning assist control method in the above embodiment.

[0082] In various aspects described herein, processor 651 may be located remote from the vehicle and in wireless communication with the vehicle. In other aspects, some of the processes described herein are performed on a processor disposed within the vehicle and others are performed by a remote processor, including taking the necessary steps to perform a single maneuver.

[0083] In some embodiments, the memory 652 may include instructions 653 (e.g., program logic) that may be executed by the processor 651 to perform various functions of the vehicle 600. The memory 652 may also include additional instructions, including instructions to send data to, receive data from, interact with, and / or control one or more of the infotainment system 610, the perception system 620, the decision control system 630, and the drive system 640.

[0084] In addition to instructions 653, memory 652 may also store data such as road maps, route information, the vehicle's location, direction, speed, and other such vehicle data, and other information. Such information may be used by vehicle 600 and computing platform 650 during operation of vehicle 600 in autonomous, semi-autonomous, and / or manual modes.

[0085] The computing platform 650 may control functions of the vehicle 600 based on input received from various subsystems, such as the drive system 640, the perception system 620, and the decision control system 630. For example, the computing platform 650 may utilize input from the decision control system 630 in order to control the turning system 633 to avoid an obstacle detected by the perception system 620. In some embodiments, the computing platform 650 may be operable to provide control over many aspects of the vehicle 600 and its subsystems.

[0086] Alternatively, one or more of the above-mentioned components may be installed or associated separately from the vehicle 600. For example, the memory 652 may exist partially or completely separately from the vehicle 600. The above-mentioned components may be communicatively coupled together in a wired and / or wireless manner.

[0087] Optionally, the above components are only examples. In actual applications, the components in the above modules may be added or deleted according to actual needs. Figure 7 It should not be understood as limiting the embodiments of the present disclosure.

[0088] Optionally, the vehicle 600 or a perception and computing device associated with the vehicle 600 (e.g., computing system 631, computing platform 650) can predict the behavior of the identified object based on the characteristics of the identified object and the state of the surrounding environment (e.g., traffic, rain, ice on the road, etc.). Optionally, each identified object depends on the behavior of each other, so all the identified objects can also be considered together to predict the behavior of a single identified object. The vehicle 600 can adjust its speed based on the predicted behavior of the identified object. In other words, the autonomous vehicle can determine what stable state the vehicle will need to adjust to (e.g., accelerate, decelerate, or stop) based on the predicted behavior of the object. In this process, other factors can also be considered to determine the speed of the vehicle 600, such as the lateral position of the vehicle 600 in the road on which it is traveling, the curvature of the road, the proximity of static and dynamic objects, and the like.

[0089] In addition to providing instructions to adjust the speed of the autonomous vehicle, the computing device may also provide instructions to modify the turning angles of vehicle 600 so that the autonomous vehicle follows a given trajectory and / or maintains safe lateral and longitudinal distances from objects near the autonomous vehicle (e.g., vehicles in adjacent lanes on the road).

[0090] The above-mentioned vehicle 600 may be a pure electric vehicle of different models, and the embodiment of the present disclosure does not make any special limitation.

[0091] In another exemplary embodiment, a computer program product is also provided. The computer program product includes a computer program executable by a programmable device. The computer program has a code portion for executing the above-mentioned vehicle turning assist control method when executed by the programmable device.

[0092] Example 4 Based on the same inventive concept, the present application also provides a computer-readable storage medium on which computer program instructions are stored. When the program instructions are executed by a processor, the steps of the vehicle turning assistance control method provided in the above embodiment are implemented.

[0093] The terms "first", "second", "third", etc. in the specification and claims of the present application and the drawings are used to distinguish different objects rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a series of steps or units are included, or optionally, steps or units not listed are included, or optionally, other steps or units inherent to these processes, methods, products or devices are included.

[0094] Only the part relevant to the present application is shown in the accompanying drawings, but not all of the content. Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processing or methods depicted as flow charts. Although the flow chart describes each operation (or step) as a sequential process, many of the operations therein can be implemented in parallel, concurrently or simultaneously. In addition, the order of each operation can be rearranged. When its operation is completed, the process can be terminated, but it can also have additional steps not included in the accompanying drawings. The process can correspond to a method, function, procedure, subroutine, subprogram, etc.

[0095] The terms "component", "module", "system", "unit", etc. used in this specification are used to represent computer-related entities, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a unit can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, and / or distributed between two or more computers. In addition, these units can be executed from various computer-readable media having various data structures stored thereon. Units can communicate through local and / or remote processes, for example, based on signals having one or more data packets (e.g., data from a second unit interacting with another unit in a local system, a distributed system, and / or a network. For example, the Internet interacts with other systems via signals).

[0096] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0097] Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Mentioning "embodiment" in this article means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present embodiment application. The appearance of this phrase in various positions in the specification is not necessarily the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It can be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0098] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A vehicle turning assist control method, characterized in that: include: In response to a start instruction of a turning assist mode, obtaining first state information of the vehicle at first intervals; Determining whether to activate a turning assist mode based on the first state information; If activated, control information is generated to control the brake to lock the outer rear wheel, and obtain target turning speed information and steering wheel angle information; Determining target torque information of front and rear axles of the vehicle based on the target turning speed information and the steering wheel angle information; After correcting the front and rear axle target torque information, the information is fed back to the front and rear electric drive assemblies of the vehicle to implement vehicle turning assist control; When the vehicle executes the turning assist control strategy, second state information of the vehicle is obtained at second intervals, and whether to exit the turning assist mode is determined based on the second state information.

2. The vehicle turning assist control method according to claim 1, characterized in that: The determining whether to activate the turning assist mode based on the first state information includes: The first state information includes current steering wheel angle, vehicle body state and gear position information; If the vehicle simultaneously satisfies: the current steering wheel angle is greater than or equal to a preset angle threshold, the vehicle body is in a stationary state, and the gear information is in a forward gear, then the turning assist mode is activated.

3. The vehicle turning assist control method according to claim 1, characterized in that: If activated, control information is generated to control the brake to lock the outer rear wheel, and obtain target turning speed information and steering wheel angle information, including: Acquiring a current accelerator pedal opening of the vehicle, and determining the target turning speed information based on the accelerator pedal opening; Based on the target turning speed information and the steering wheel angle information, a front wheel target speed, a rear wheel target speed and a vehicle body target yaw angular velocity of the vehicle are obtained.

4. The vehicle turning assist control method according to claim 3, characterized in that: The method of obtaining a front wheel target speed, a rear wheel target speed, and a vehicle body target yaw angular velocity of the vehicle based on the target turning vehicle speed information and the steering wheel angle information includes: The calculation expression of the target turning speed is: v_drvReq=MAP1(k_Acc); The calculation expression of the front wheel target speed is: nf_tagt= f1(v_drvReq, θ); The calculation expression of the rear wheel target speed is: nr_tagt=f2(v_drvReq, θ); The calculation expression of the vehicle body target yaw angular velocity is: δ_drvReq =MAP2(v_drvReq, θ); Where v_drvReq is the target turning speed, k_Acc is the current accelerator pedal opening of the vehicle, and θ is the steering wheel angle.

5. A vehicle turning assist control method according to any one of claims 1 to 4, characterized in that: The determining of the front and rear axle target torque information of the vehicle based on the target turning speed information and the steering wheel angle information includes: According to the front wheel target speed and the rear wheel target speed, the front axle target torque information and the rear axle target torque information are determined respectively, wherein: The calculation expression of the front axle target torque is: Tf_req = PID1 (nf_tagt, (n_fi + n_fo) / 2); The calculation expression of the rear axle target torque is: Tr_req = PID2 (nr_tagt, n_ri / 2); Where nf_tagt is the target wheel speed of the front wheel, nr_tagt is the target wheel speed of the rear wheel, (n_fi+n_fo) / 2 is the average value of the input variables, and n_ri / 2 is half of the input variables.

6. A vehicle turning assist control method according to any one of claims 1 to 4, characterized in that: After the front and rear axle target torque information is corrected, the information is fed back to the front and rear electric drive assemblies of the vehicle to implement vehicle turning assist control, including: Acquiring an actual center-of-mass vehicle speed, and determining a center-of-mass vehicle speed correction coefficient based on the current actual center-of-mass vehicle speed and a target turning speed; Acquiring a current yaw rate of the vehicle, and determining a yaw moment correction torque based on the current yaw rate and a target yaw rate of the vehicle body; Based on the yaw moment correction torque and the mass center vehicle speed correction coefficient, the front and rear axle target torque information is corrected to obtain the front and rear electric drive assembly request torque, wherein: The calculation expression of the center of mass speed correction coefficient is: K_Vspd = PID3 (v_drvReq, v_act); The calculation expression of the front axle target torque correction is: Tf_ad1_req = Tf_req*K_Vspd; The calculation expression of the rear axle target torque correction is: Tr_ad1_req = Tr_req*K_Vspd; The calculation expression of the yaw moment correction torque is: ΔT=MAP3(δ_drvReq, δ); The calculation expression of the front electric drive assembly request torque is: Tf_ad2_req= Tf_ad1_req-ΔT; The calculation expression of the rear electric drive assembly request torque is: Tf_ad2_req=Tf_ad2_req-ΔT; Where K_Vspd is the correction coefficient of the vehicle speed at the center of mass, δ_drvReq is the target yaw rate of the vehicle body, δ is the current yaw rate of the vehicle body, ΔT is the yaw moment correction torque, and Tf_req1 and Tf_req2 are the target torques of the front and rear axles.

7. The vehicle turning assist control method according to claim 1, characterized in that: When the vehicle executes the turning assist control strategy, obtaining second state information of the vehicle at second intervals, and determining whether to exit the turning assist mode based on the second state information, includes: The second state information includes actual steering wheel angle, brake pedal state, gear position information and current vehicle speed information; If the vehicle meets any of the following conditions: the actual steering wheel angle is less than the preset angle threshold, the brake pedal is in the depressed state, the gear information is switched to non-D gear, or the current vehicle speed information is greater than the preset vehicle speed threshold, then the turning assist mode is exited.

8. A turning assist control device for a vehicle, characterized in that: include: A first acquisition module is configured to acquire first state information of the vehicle at first intervals when the user turns on the turning assist mode, and determine whether to activate the turning assist mode based on the first state information; a brake module configured to generate control information to control the brake to lock the outer rear wheel when a vehicle turn assist mode is activated; A second acquisition module is configured to acquire target turning vehicle speed information and steering wheel angle information when the vehicle turning assist mode is activated; a determination module configured to determine target torque information of front and rear axles of the vehicle based on the target turning speed information and the steering wheel angle information; A correction module is configured to determine a yaw moment correction torque based on the current yaw angular velocity of the vehicle and the target yaw angular velocity of the vehicle body; an execution module, configured to correct the front and rear axle target torque information and feed it back to the front and rear electric drive assemblies of the vehicle to implement vehicle turning assist control; The third acquisition module is configured to acquire second state information of the vehicle at second intervals when the vehicle executes the turning assist control strategy, and determine whether to exit the turning assist mode based on the second state information.

9. A vehicle, characterized in that: include: processor; a memory for storing instructions executable by the processor; Wherein, the processor is configured to: The steps of implementing a vehicle turning assist control method according to any one of claims 1 to 7.

10. A computer-readable storage medium having computer program instructions stored thereon, characterized in that: When the program instructions are executed by a processor, the steps of a vehicle turning assist control method according to any one of claims 1 to 7 are implemented.

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