Electric vehicle turning control method, vehicle controller and electric vehicle

Abstract

The invention provides an electric vehicle turning control method, a vehicle controller and an electric vehicle, and is applied to the technical field of electric vehicles. The control method is used for controlling a driving system of the electric vehicle to adjust torque output to left and right side wheels when the electric vehicle turns so as to improve turning stability, and comprises the following steps: when the electric vehicle turns left, after a first moment when a steering wheel turns left and before a second moment when the steering wheel turns right, the torque output to the left and right side wheels is adjusted; controlling the torque output by the driving system to the left wheel to be smaller than the torque output by the driving system to the right wheel; after the second moment, the rightward angular speed of the steering wheel is larger than the preset angular speed threshold value, the torque output by the driving system to the left side wheels is controlled to be larger than the torque output by the driving system to the right side wheels, and the torque difference of the left side wheels and the right side wheels is controlled to be increased along with increase of the rightward angular speed of the steering wheel. In this way, when the steering wheel is emergently returned, the response speed of the electric vehicle to emergency returning is increased, the posture of the vehicle body is corrected in time, and the turning stability of the electric vehicle is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric vehicles, and particularly relates to a control method for an electric vehicle to turn a curve, a vehicle controller and an electric vehicle. BACKGROUND

[0002] In the driving process of the electric vehicle to turn a curve, for example, in a U-shaped curve or other curve turning scenarios, when the driver turns the steering wheel at too large an angle, the electric vehicle may turn too much or spin out. At this time, the steering angle of the electric vehicle is adjusted by turning the steering wheel back to the normal position in an emergency, but the vehicle body will maintain the original movement trend due to inertia in the process of emergency turning back, so that the electric vehicle cannot respond to the driver's intention to turn back in time, and the stability of the electric vehicle is easily lost. SUMMARY

[0003] Embodiments of the present application provide a control method for an electric vehicle to turn a curve, a vehicle controller and an electric vehicle, which is used to improve the response speed of the electric vehicle to emergency turning back of the steering wheel, correct the vehicle body posture in time, and improve the curve turning stability of the electric vehicle when the steering wheel is turned back in an emergency in the driving process of the vehicle to turn a curve.

[0004] In a first aspect, embodiments of the present application provide a control method for an electric vehicle to turn a curve, which is used to control a drive system of the electric vehicle to adjust the torque output to a left wheel and a right wheel coaxial with each other to improve the curve turning stability of the electric vehicle in the driving process of the electric vehicle to turn a curve, and the control method comprises: in the driving process of the electric vehicle to turn left, after a first time when the steering wheel starts to turn left, and before a second time when the steering wheel starts to turn right, controlling the torque output to the left wheel by the drive system to be less than the torque output to the right wheel; after the second time, when the angular velocity of the steering wheel turning right is greater than a preset angular velocity threshold, controlling the torque output to the left wheel by the drive system to be greater than the torque output to the right wheel, and controlling the torque difference between the torque output to the left wheel and the torque output to the right wheel to increase with the increase of the angular velocity of the steering wheel turning right.

[0005] In the embodiment, during the driving process of the electric vehicle turning left, the torque output to the left wheel coaxial with the driving system is controlled to be less than the torque output to the right wheel, a torque difference between the left and right wheels generates a yaw moment in the same direction as the steering wheel turning angle, which assists the electric vehicle to turn left. By detecting that the steering wheel starts to turn right and the angular velocity of the steering wheel to the right is greater than a preset angular velocity threshold, the electric vehicle entering the emergency straightening condition is detected. In this case, by controlling the torque output to the left wheel coaxial with the driving system to be greater than the torque output to the right wheel, a torque difference between the left and right wheels coaxial with the driving system generates a yaw moment in the opposite direction of the steering wheel turning angle, which can offset the original yaw trend caused by the vehicle body inertia, quickly correct the vehicle body posture, and improve the response speed of the emergency straightening. Moreover, by increasing the torque difference between the torque output to one left wheel and the torque output to one right wheel with the increase of the angular velocity of the steering wheel to the right, the torque difference between the left and right wheels coaxial with the driving system is flexibly determined according to the angular velocity of the steering wheel to the right, so as to timely respond to different emergency straightening intentions corresponding to different angular velocities of the steering wheel to the right, quickly correct the vehicle body posture, improve the over-steering problem of the electric vehicle, and improve the cornering stability of the electric vehicle. For example, the more serious the over-steering of the electric vehicle to the left, the greater the original yaw trend caused by the vehicle body inertia, and the greater the angular velocity of the steering wheel to the right for adjusting the steering angle. By controlling the torque difference between the left and right wheels coaxial with the driving system, the greater the torque difference between the left and right wheels coaxial with the driving system generates the greater yaw moment in the opposite direction of the steering wheel turning angle, which can better offset the original yaw trend caused by the vehicle body inertia, and quickly correct the vehicle body posture.

[0006] In an embodiment of the first aspect, the control method specifically comprises: after the second time, when the yaw angular velocity of the electric vehicle is greater than a preset yaw angular velocity, the sum of the torque output to one left wheel and the torque output to one right wheel by the driving system decreases with the increase of the yaw angular velocity; and when the yaw angular velocity of the electric vehicle is less than or equal to the preset yaw angular velocity, the sum of the torque output to one left wheel and the torque output to one right wheel by the driving system does not change with the increase of the yaw angular velocity.

[0007] In the embodiment, the electric vehicle is in the emergency return-to-straight condition, and if the yaw angular velocity of the electric vehicle is greater than the preset yaw angular velocity, the vehicle body is on the edge of losing control, and the electric vehicle can spin out. Thus, in the case that the electric vehicle can spin out, the sum of the torques of the left and right wheels coaxial with the electric vehicle is reduced to reduce the acceleration of the electric vehicle, reduce the original yaw trend caused by the inertia of the vehicle body, inhibit the spin-out of the electric vehicle, and avoid the loss of stability of the electric vehicle. Moreover, by reducing the sum of the torques of the left and right wheels coaxial with the electric vehicle, the original yaw trend caused by the inertia of the vehicle body can be reduced, the resistance of the inertia of the vehicle body to the correction of the attitude of the vehicle body can be weakened, and the response speed of the vehicle to the emergency return-to-straight can be improved.

[0008] In an embodiment of the first aspect, the control method specifically comprises: after the second time, the torque difference between the torque output by the driving system to one left wheel and the torque output by the driving system to one right wheel is less than or equal to the torque difference threshold.

[0009] In the embodiment, after it is detected that the electric vehicle enters the emergency return-to-straight condition, the torque difference between the torque output by the driving system to the left wheel coaxial with the electric vehicle and the torque output by the driving system to the right wheel is controlled to be less than or equal to the torque difference threshold, so as to limit the upper limit of the yaw moment opposite to the turning direction of the steering wheel generated by the torque difference between the left and right wheels coaxial with the electric vehicle, to avoid that the tire friction circle limit of the wheel is broken due to the yaw moment opposite to the turning direction of the steering wheel being too large, so as to avoid the loss of stability of the electric vehicle.

[0010] In an embodiment of the first aspect, the control method specifically comprises: after the second time, the angular velocity of the steering wheel to the right is less than the first preset angular velocity, the torque difference between the torque output by the driving system to one left wheel and the torque output by the driving system to one right wheel increases with the increase of the angular velocity of the steering wheel to the right; and the angular velocity of the steering wheel to the right is greater than or equal to the first preset angular velocity, the torque difference between the torque output by the driving system to one left wheel and the torque output by the driving system to one right wheel does not change with the increase of the angular velocity of the steering wheel to the right.

[0011] In the embodiment, after the electric vehicle enters the emergency return-to-straight condition, the tire grip limit is restricted, the size of the torque difference between the coaxial left and right wheels that can be used to correct the vehicle body posture is restricted, and if the friction circle limit is broken, the electric vehicle will lose stability. If the angular velocity of the steering wheel to the right is greater than the first preset angular velocity, the return-to-straight speed of the steering wheel is fast, which indicates that, at the return-to-straight angular velocity, the lateral acceleration corresponding to the yaw moment generated by the torque difference between the coaxial left and right wheels may break the tire grip limit in the process of correcting the vehicle body posture and avoiding the tendency of the electric vehicle to spin out. In the case where the angular velocity of the steering wheel to the right is less than or equal to the first preset angular velocity, the torque difference between the torque output by the control driving system to one left wheel and the torque output to one right wheel is increased with the increase of the angular velocity of the steering wheel to the right, so that the torque difference between the coaxial left and right wheels is flexibly determined according to the lateral acceleration, and the yaw moment generated by the torque difference is fast enough to correct the vehicle body posture and avoid the tendency of the electric vehicle to spin out. In the case where the angular velocity of the steering wheel to the right is greater than the first preset angular velocity, the torque difference between the torque output by the control driving system to one left wheel and the torque output to one right wheel does not change with the increase of the angular velocity of the steering wheel to the right, so as to ensure that the yaw moment generated by the torque difference between the coaxial left and right wheels does not break the tire grip limit, and the electric vehicle loses stability.

[0012] In an embodiment of the first aspect, the control method specifically comprises: after the first time and before the second time, the opening degree of the accelerator pedal of the electric vehicle is the first accelerator pedal opening degree, and the torque output by the control driving system to the electric vehicle is the first torque sum; after the second time, the opening degree of the accelerator pedal is the first accelerator pedal opening degree, and the torque output by the control driving system to the electric vehicle is reduced to be less than the first torque sum.

[0013] In the embodiment, after the electric vehicle enters the emergency return-to-straight condition, the large acceleration of the electric vehicle may cause the grip of the wheels to break the friction circle limit. By controlling the torque sum of the electric vehicle to be less than the first torque sum indicated by the first accelerator pedal opening degree, that is, by actively reducing the torque of the control driving system, the acceleration of the electric vehicle after entering the emergency return-to-straight condition is limited, the response speed of the vehicle to the emergency return-to-straight is improved, the electric vehicle loses stability is avoided, and the driving safety is ensured.

[0014] In an embodiment of the first aspect, the control method specifically comprises: after the second time, the greater the first accelerator pedal opening degree, the greater the reduction amount of the torque sum output by the control driving system to the electric vehicle.

[0015] In the embodiment, the greater the yaw rate is after the electric vehicle enters the emergency return-to-straight condition, the more likely the electric vehicle loses stability during acceleration. The greater the torque difference between the torque output by the drive system to the electric vehicle and the torque reduction amount is, the greater the force of the drive system to actively control the torque reduction, the greater the force of the acceleration limitation of the electric vehicle after entering the emergency return-to-straight condition, and the size of the torque difference is flexibly determined according to the size of the first accelerator pedal opening, so as to accurately control the force of the drive system to reduce the torque under different first accelerator pedal openings, guarantee the stability of the electric vehicle, and ensure driving safety.

[0016] In an embodiment of the first aspect, the control method specifically comprises: after the second time, when the yaw rate of the electric vehicle is a first yaw rate, the torque difference between the torque output by the drive system to one left wheel or the torque output by the drive system to one right wheel and the torque indicated by the opening of the accelerator pedal is a first torque difference; when the yaw rate is a second yaw rate greater than the first yaw rate, the torque difference between the torque output by the drive system to one left wheel or the torque output by the drive system to one right wheel and the torque indicated by the opening of the accelerator pedal is a second torque difference, and the second torque difference is greater than the first torque difference.

[0017] In the embodiment, after the electric vehicle enters the emergency return-to-straight condition, the torque difference between the torque output by the drive system to the left wheel or the right wheel and the torque indicated by the opening of the accelerator pedal is greater when the yaw rate is greater, and the torque difference between the torque output by the drive system to the left wheel or the right wheel and the torque indicated by the opening of the accelerator pedal is smaller when the yaw rate is smaller, so as to accurately limit the torque output by the drive system to the left wheel or the right wheel according to the yaw rate and the accelerator pedal opening, accurately limit the acceleration of the electric vehicle according to the yaw rate and the accelerator pedal opening, better help to timely respond to the emergency return-to-straight while guaranteeing the stability of the electric vehicle and ensuring driving safety.

[0018] In an embodiment of the first aspect, the control method specifically comprises: after the second time, increasing the torque output to one left wheel by the drive system, or reducing the torque output to one right wheel by the drive system.

[0019] In the embodiment, after the electric vehicle enters the emergency return-to-straight condition, the torque difference between the torque output by the driving system to the left wheel and the torque output to the right wheel is increased by specifically controlling the driving system to increase the torque output to the left wheel and / or to reduce the torque output to the right wheel, the yaw moment in the direction opposite to the steering wheel angle direction generated by the torque difference between the left and right wheels can be increased, so that the yaw moment in the direction opposite to the steering wheel angle direction can offset the original yaw trend caused by the vehicle body inertia, which is beneficial to the timely response of the electric vehicle to the emergency return-to-straight, the correction of the vehicle body posture, and the improvement of the cornering stability of the electric vehicle.

[0020] In an embodiment of the first aspect, the control method specifically comprises: after the second time, the greater the steering wheel left turning angle, the greater the torque difference between the torque output by the driving system to the left wheel and the torque output to the right wheel.

[0021] In the embodiment, when the electric vehicle enters the emergency return-to-straight condition, the greater the steering wheel left turning angle, the more serious the over-steering of the electric vehicle to the left, and the greater the original yaw trend caused by the vehicle body inertia. By increasing the torque difference between the torque output by the driving system to the left wheel and the torque output to the right wheel, the yaw moment in the direction opposite to the steering wheel angle direction generated by the torque difference between the left and right wheels can be increased, which can help to timely respond to the emergency return-to-straight in the case of serious over-steering of the vehicle to the left, offset the original yaw trend caused by the vehicle body inertia, correct the vehicle body posture, and improve the cornering stability of the electric vehicle.

[0022] In an embodiment of the first aspect, the control method specifically comprises: after the second time, the greater the vehicle speed of the electric vehicle, the greater the torque difference between the torque output by the driving system to the left wheel and the torque output to the right wheel.

[0023] In the embodiment, when the electric vehicle enters the emergency return-to-straight condition, the greater the vehicle speed of the electric vehicle, the greater the original yaw trend caused by the vehicle body inertia, and the more likely the electric vehicle to lose stability. By increasing the torque difference between the torque output by the driving system to the left wheel and the torque output to the right wheel, the yaw moment in the direction opposite to the steering wheel angle direction generated by the torque difference between the left and right wheels can be increased, which can help to timely respond to the emergency return-to-straight in the case of different vehicle speeds, offset the original yaw trend caused by the vehicle body inertia, correct the vehicle body posture, and improve the cornering stability of the electric vehicle.

[0024] In a second aspect, the embodiments of the present application provide a vehicle controller, the vehicle controller being configured to control a drive system of an electric vehicle, and the vehicle controller being configured to: during a left turning process of the electric vehicle, after a first time point at which a steering wheel starts to turn left and before a second time point at which the steering wheel starts to turn right, control a torque output by the drive system to a left wheel to be less than a torque output by the drive system to a right wheel, the left wheel and the right wheel being coaxial wheels; after the second time point, when an angular velocity of the steering wheel rightward is greater than a preset angular velocity threshold, control the torque output by the drive system to the left wheel to be greater than the torque output by the drive system to the right wheel, and control a torque difference between the torque output by the drive system to the left wheel and the torque output by the drive system to the right wheel to increase with an increase of the angular velocity of the steering wheel rightward.

[0025] In the embodiments, during the left turning process of the electric vehicle, by controlling the torque output by the drive system to the coaxial left wheel to be less than the torque output by the drive system to the right wheel, a torque difference between the left wheel and the right wheel generates a yaw moment in the same direction as a turning angle direction of the steering wheel, thereby assisting the electric vehicle to turn left. By detecting that the steering wheel starts to turn right and that the angular velocity of the steering wheel rightward is greater than the preset angular velocity threshold, the electric vehicle is detected to enter an emergency straightening condition. In this case, by controlling the torque output by the drive system to the coaxial left wheel of the electric vehicle to be greater than the torque output by the drive system to the right wheel, a torque difference between the coaxial left wheel and the right wheel generates a yaw moment in the opposite direction of the turning angle direction of the steering wheel, thereby offsetting an original yaw trend caused by a vehicle body inertia, quickly correcting a vehicle body posture, and improving a response speed to the emergency straightening. Moreover, by controlling the torque difference between the torque output by the drive system to the left wheel and the torque output by the drive system to the right wheel to increase with the increase of the angular velocity of the steering wheel rightward, the torque difference between the coaxial left wheel and the right wheel is flexibly determined according to the angular velocity of the steering wheel rightward, thereby responding to different emergency straightening intentions corresponding to different angular velocities of the steering wheel rightward in time, guaranteeing the quick correction of the vehicle body posture, improving the over-steering of the electric vehicle, and improving the cornering stability of the electric vehicle. For example, the more serious the over-steering of the electric vehicle leftward, the greater the original yaw trend caused by the vehicle body inertia, and the greater the angular velocity of the steering wheel rightward for adjusting the steering angle, and the greater the torque difference between the coaxial left wheel and the right wheel, the greater the yaw moment in the opposite direction of the turning angle direction of the steering wheel generated by the torque difference between the coaxial left wheel and the right wheel, thereby better offsetting the original yaw trend caused by the vehicle body inertia, and guaranteeing the quick correction of the vehicle body posture.

[0026] In an embodiment of the second aspect, the vehicle controller is specifically configured to: after the second time, when the yaw rate of the electric vehicle is greater than the preset yaw rate, the sum of the torque output by the drive system to the left wheel and the torque output by the drive system to the right wheel decreases with the increase of the yaw rate of the electric vehicle; when the yaw rate of the electric vehicle is less than or equal to the preset yaw rate, the sum of the torque output by the drive system to the left wheel and the torque output by the drive system to the right wheel does not change with the increase of the yaw rate of the electric vehicle.

[0027] In the embodiment, the electric vehicle is in the emergency straightening condition, if the yaw rate of the electric vehicle is greater than the preset yaw rate, the vehicle body is on the verge of losing control, and the electric vehicle may spin. Therefore, in the case that the electric vehicle may spin, the sum of the torques of the coaxial left and right wheels of the electric vehicle is reduced to reduce the acceleration of the electric vehicle, reduce the original yaw trend caused by the inertia of the vehicle body, inhibit the spin of the electric vehicle, and avoid the loss of stability of the electric vehicle. Moreover, by reducing the sum of the torques of the coaxial left and right wheels of the electric vehicle, the original yaw trend caused by the inertia of the vehicle body can be reduced to weaken the resistance of the inertia of the vehicle body to the correction of the vehicle body posture, and improve the response speed of the vehicle to the emergency straightening.

[0028] In a third aspect, the embodiments of the present application provide an electric vehicle. The electric vehicle comprises a drive system and a wheel, and the drive system comprises a vehicle controller. The vehicle controller is configured to control the torque output by the drive system to the wheel. The vehicle controller is specifically configured to: during the driving process of the electric vehicle turning left, after a first time when the steering wheel starts to turn left and before a second time when the steering wheel starts to turn right, control the torque output by the drive system to a left wheel to be less than the torque output by the drive system to a right wheel, the left wheel and the right wheel being coaxial wheels; after the second time, when the angular velocity of the steering wheel to the right is greater than a preset angular velocity threshold, control the torque output by the drive system to the left wheel to be greater than the torque output by the drive system to the right wheel, and control the torque difference between the torque output by the drive system to the left wheel and the torque output by the drive system to the right wheel to increase with the increase of the angular velocity of the steering wheel to the right.

[0029] The supplementary and technical effects of the solutions provided in the second aspect and the third aspect above can be referred to the corresponding descriptions of the first aspect, and will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 FIG. 1 shows a schematic diagram of an electric vehicle provided by an embodiment of the present application;

[0031] Figure 2 FIG. 2 shows a schematic diagram of an electric vehicle architecture provided by an embodiment of the present application;

[0032] Figure 3A driving scene schematic diagram of an electric vehicle is shown.

[0033] Figure 4 A timing relationship diagram between a steering wheel rotation angle and an angular velocity, a driving system output torque and a torque difference is shown.

[0034] Figure 5 A schematic diagram of a relationship between a torque difference threshold and a lateral acceleration is shown.

[0035] Figure 6 A schematic diagram of a relationship between a yaw rate correction factor and an angle difference of a steering wheel rotation angle is shown.

[0036] Figure 7 A schematic diagram of a relationship between a torque correction factor and a yaw rate is shown.

[0037] Figure 8 A schematic diagram of a motor controller is shown.

[0038] Figure 9 A schematic diagram of a vehicle controller is shown. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be described below with reference to the drawings.

[0040] In the embodiments of the present application, the prefix words such as "first", "second" are only used to distinguish different description objects, and have no limiting effect on the position, order, priority, quantity or content of the described objects. The use of ordinal words in the embodiments of the present application to distinguish the described objects does not limit the described objects, and the description of the described objects should be referred to the description of the context in the claims or embodiments, and should not be limited by the use of such prefix words.

[0041] In the driving process of the electric vehicle turning, for example, in the over-turning scene such as U-shaped curve, when the driver turns the steering wheel angle too large, the electric vehicle may over-steer or spin. At this time, the steering angle of the electric vehicle is adjusted by turning the steering wheel back to normal, but in the process of emergency back to normal, the vehicle body will maintain the original motion trend due to inertia, so that the electric vehicle cannot respond to the driver's intention to turn back in time, which easily leads to the loss of stability of the electric vehicle.

[0042] In view of this, the embodiment of the present application provides a control method of an electric vehicle turning a corner, a vehicle controller and the electric vehicle. Taking the process of the electric vehicle turning left as an example, in the process of the electric vehicle turning left, after a first time point when the steering wheel starts to turn left and before a second time point when the steering wheel starts to turn right, the torque output by the driving system to one left wheel is less than the torque output to one right wheel. After the second time point when the steering wheel starts to turn right, if the angular velocity of the steering wheel to the right is greater than a preset angular velocity threshold, the torque output by the driving system to one left wheel is greater than the torque output to one right wheel, and the torque difference between the torque output to one left wheel and the torque output to one right wheel increases with the increase of the angular velocity of the steering wheel to the right. In this way, the response speed of the electric vehicle to the emergency straightening is improved, and the stability of the electric vehicle turning a corner is improved.

[0043] Reference is made to Figure 1 , Figure 1 A schematic diagram of an electric vehicle provided by the embodiment of the present application is shown. As shown in Figure 1 , the electric vehicle 100 includes a driving system 110, a power battery 120 connected with the driving system 110 and a vehicle controller 130. The driving system 110 is used to drive the electric vehicle 100. The power battery 120 is used to provide power to the driving system 110. The driving system 110 is used to receive power from the power battery 120 and provide power for the electric vehicle 100. The driving system 110 can also be referred to as a power assembly.

[0044] According to the position of the wheels in the electric vehicle 100, the four wheels can be divided into a left front wheel FL, a right front wheel FR, a left rear wheel BL and a right rear wheel BR. According to the axle division, the left front wheel and the right front wheel are coaxial and connected through a front axle among the four wheels. The left rear wheel and the right rear wheel are coaxial and connected through a rear axle. According to the position division, the left front wheel and the left rear wheel are on the same side and located on the left side among the four wheels, and the right front wheel and the right rear wheel are on the same side and located on the right side. That is, among the four wheels of the electric vehicle 100, the left front wheel and the right front wheel are coaxial wheels, and the left rear wheel and the right rear wheel are coaxial wheels; the left front wheel and the left rear wheel are same-side wheels, and the right front wheel and the right rear wheel are same-side wheels.

[0045] The electric vehicle 100 in the embodiment of the present application can be any one of different types of automobiles such as a car, a truck, a passenger car, etc., can also be a three-wheeled vehicle, a two-wheeled vehicle, a train, etc., a transportation device carrying people or goods, or other types of transportation tools driven by a power battery.

[0046] This application does not limit the specific type of powertrain in its embodiments; these are merely examples and not limitations. The aforementioned powertrain can be a centralized powertrain, a hub motor powertrain, or a wheel-side motor powertrain. Specifically, the hub motor powertrain directly mounts the motor and reducer within the wheel rim, eliminating transmission components such as half-shafts, universal joints, differentials, and gearboxes; the wheel-side motor powertrain mounts the motor on the subframe.

[0047] See Figure 2 , Figure 2 A schematic diagram of an electric vehicle architecture provided in an embodiment of this application is shown.

[0048] See Figure 2 (a) Electric vehicle 100 is a three-wheel drive vehicle, and the drive system 110 includes drive motors 111 for the two front wheels and motor controllers 121 for the drive motors 111, drive motor 112 for the left rear wheel and motor controllers 122 for the drive motor 112, and drive motor 113 for the right rear wheel and motor controllers 123 for the drive motor 113.

[0049] In one embodiment, the drive system of the three-wheel drive vehicle may further include drive motors and motor controllers for the coaxial left and right side wheels, drive motors and motor controllers for the left front wheel, and drive motors and motor controllers for the right front wheel.

[0050] When the electric vehicle 100 is in a driving state, each drive motor in the drive system 110 provides driving force to the electric vehicle 100. Specifically, when the electric vehicle 100 is in a driving state, the vehicle controller 130 calculates the torque demand of the electric vehicle and outputs torque signals to the motor controllers of each drive motor. Each motor controller receives torque signals from the power battery 120 (e.g., ...). Figure 1 The electrical energy (as shown) is used to control the torque indicated by the output torque signal of the corresponding drive motor.

[0051] The drive motors in the electric vehicle 100 with energy recovery function can also be used to provide braking force for the electric vehicle 100. Specifically, when the electric vehicle 100 is in a braking state, the vehicle controller 130 receives a braking signal and sends an energy recovery command to each motor controller. In response to the energy recovery command, each motor controller controls the corresponding drive motor to operate in a power generation state. Each drive motor converts the kinetic energy of the electric vehicle's wheels into electrical energy and outputs a reverse torque to the wheels of the electric vehicle 100 to provide braking force to the electric vehicle 100. The direction of the reverse torque is opposite to the direction of wheel rotation.

[0052] The driving system 110 and the vehicle controller 130 are connected by communication, and the specific communication connection mode is not limited in the embodiments of the present application. For example, the motor controller in the driving system 110 and the vehicle controller 130 can communicate through a private CAN network, and the motor controller in the driving system 110 and the vehicle controller 130 can communicate through a public CAN network.

[0053] Referring to Figure 2 In the (b) electric vehicle 100, the driving system 110 includes a driving motor 114 and a motor controller 124 of the driving motor 114 for the left front wheel, a driving motor 115 and a motor controller 125 of the driving motor 115 for the right front wheel, a driving motor 112 and a motor controller 122 of the driving motor 112 for the left rear wheel, and a driving motor 113 and a motor controller 123 of the driving motor 113 for the right rear wheel.

[0054] The architecture of the embodiments of the present application is described above, and the control method of the electric vehicle over the bend provided by the present application is described below in combination with specific embodiments.

[0055] The control method of the electric vehicle over the bend provided by the embodiments of the present application is used to control the driving system of the electric vehicle to adjust the torque output to one left side wheel and one right side wheel coaxial with each other during the driving process of the electric vehicle over the bend, so as to improve the over-bend stability of the electric vehicle.

[0056] Taking the process of the electric vehicle turning left as an example, the control method of the electric vehicle over the bend provided by the embodiments of the present application includes the following steps.

[0057] During the driving process of the electric vehicle turning left, after the first moment when the steering wheel starts to turn left and before the second moment when the steering wheel starts to turn right, the torque output to one left side wheel by the driving system is controlled to be less than the torque output to one right side wheel.

[0058] During the driving process of the electric vehicle turning left, after the steering wheel starts to turn left at the first moment, the torque output to one left side wheel coaxial with one right side wheel by the driving system is controlled to be less than the torque output to one right side wheel, and the torque difference between the left and right side wheels coaxial with each other causes a rotation moment around the vertical axis, i.e. a yaw moment, and the torque difference between the left and right side wheels produces a yaw moment in the same direction as the steering wheel angle, which assists the electric vehicle to turn left.

[0059] During the driving process of the electric vehicle turning left, if the steering wheel angle of the steering wheel turning left is too large, causing the turning angle of the electric vehicle turning left to be too large, the steering wheel is controlled to start to turn right at the second moment to perform emergency right return of the steering wheel, reduce the turning angle of the electric vehicle turning left, and correct the situation of the electric vehicle turning left excessively.

[0060] In some embodiments, the steering wheel of the electric vehicle can be controlled to rotate by the auxiliary driving system. In other embodiments, the steering wheel of the electric vehicle can also be operated by the driver. The embodiments of the present application do not limit the implementation manner of operating the steering wheel of the electric vehicle to rotate.

[0061] After the second time, the angular velocity of the steering wheel turning right is greater than the preset angular velocity threshold, the control system controls the torque output to the left wheel to be greater than the torque output to the right wheel, and controls the torque difference between the torque output to the left wheel and the torque output to the right wheel to increase with the increase of the angular velocity of the steering wheel turning right.

[0062] In the driving process of the electric vehicle turning left, in the case of emergency right correction, the steering wheel turns right, the angular velocity direction of the steering wheel is right, and the turning angle direction of the steering wheel is left, i.e., the turning angle direction of the steering wheel is opposite to the angular velocity direction of the steering wheel.

[0063] In an embodiment, in the driving process of the electric vehicle turning left, when the control system controls the steering wheel to start turning right, if the angular velocity of the steering wheel turning right is less than or equal to the preset angular velocity threshold, it indicates that the electric vehicle is in a non-emergency correction working condition; if the angular velocity of the steering wheel turning right is greater than the preset angular velocity threshold, it indicates that the electric vehicle is in an emergency correction working condition.

[0064] After the second moment, by detecting that the steering wheel starts to turn right, the angular velocity of the steering wheel right is greater than the preset angular velocity threshold, the detection of the electric vehicle entering the emergency straightening condition is realized. In this case, by controlling the driving system to output a torque to a left wheel of the electric vehicle coaxial with a right wheel, the torque difference between the left and right wheels coaxial produces a yaw moment opposite to the direction of the steering wheel angle, which can offset the original yaw trend brought by the vehicle body inertia, realize the rapid correction of the vehicle body posture, and improve the response speed of the emergency straightening. Moreover, by controlling the torque difference between the torque output to the left wheel and the torque output to the right wheel to increase with the increase of the angular velocity of the steering wheel right, the torque difference between the left and right wheels coaxial is flexibly determined according to the angular velocity of the steering wheel right, so as to realize the timely response to different emergency straightening intentions corresponding to different angular velocities of the steering wheel right, guarantee the rapid correction of the vehicle body posture, improve the problem of oversteering of the electric vehicle, and improve the over-bend stability of the electric vehicle. For example, the more serious the oversteering of the electric vehicle to the left, the greater the original yaw trend brought by the vehicle body inertia, the greater the angular velocity of the steering wheel right to turn right to adjust the steering angle, and the greater the torque difference between the left and right wheels coaxial through control, so that the torque difference between the left and right wheels coaxial produces a yaw moment opposite to the direction of the steering wheel angle, which can better offset the original yaw trend brought by the vehicle body inertia, and guarantee the rapid correction of the vehicle body posture.

[0065] For ease of understanding, see Figure 3 and Figure 4 , Figure 3 shows a driving scene of an electric vehicle provided by an embodiment of the application, Figure 4 shows a timing relationship diagram between the angle and angular velocity of the steering wheel and the torque and torque difference output by the driving system.

[0066] In the driving process of the electric vehicle turning left, as Figure 4 shows, at the first moment t1, the steering wheel starts to turn left, and the steering angle of the steering wheel starts to increase. At the second moment t2, the steering wheel starts to turn right, and the steering angle of the steering wheel starts to decrease.

[0067] After the first moment t1 when the steering wheel starts to turn left and before the second moment t2 when the steering wheel starts to turn right, by controlling the driving system to output a torque to a left wheel less than a torque output to a right wheel, due to the torque difference between the left and right wheels coaxial, the electric vehicle generates a left yaw moment, and the electric vehicle is in a driving state of turning left, as shown in Figure 3 position 1.

[0068] In one embodiment, the driving system can be controlled to output a torque to one left wheel that is less than a torque output to one right wheel throughout the period between the first time t1 and the second time t2, and the driving system can be controlled to output a torque to one left wheel that is less than a torque output to one right wheel for a portion of the period between the first time t1 and the second time t2 (as shown in FIG. 6B). In other words, the driving system outputs a torque to one left wheel that is less than a torque output to one right wheel at any time between the first time t1 and the second time t2. Figure 4

[0069] After the second time t2, the electric vehicle enters the emergency straightening condition by detecting that the steering wheel starts to turn right and the angular velocity of the steering wheel turning right is greater than the preset angular velocity threshold. When the electric vehicle enters the emergency straightening condition, the driving system can be controlled to output a torque to one left wheel that is greater than a torque output to one right wheel, as shown in position 2 in FIG. 6C, so that a yaw moment opposite to the direction of the steering wheel is generated between the left and right wheels coaxial with the steering wheel, which can offset the original yaw trend caused by the inertia of the vehicle body, correct the vehicle body posture quickly, and improve the response speed to the emergency straightening. Figure 3

[0070] In one embodiment, the angular velocity of the steering wheel turning right that is greater than the preset angular velocity threshold can occur at the time when the second time t2 starts, or at any time after the second time t2 (as shown in FIG. 6D). In addition, the driving system can be controlled to output a torque to one left wheel that is greater than a torque output to one right wheel starting from the second time t2, or the driving system can be controlled to output a torque to one left wheel that is greater than a torque output to one right wheel for a portion of the period after the second time t2 (as shown in FIG. 6E). In other words, the driving system outputs a torque to one left wheel that is greater than a torque output to one right wheel at any time after the second time t2. Figure 4 Figure 4

[0071] ​​​​And, when the angular velocity of the steering wheel turning right is greater than the preset angular velocity threshold, by controlling the torque difference between the torque output to one left side wheel and the torque output to one right side wheel to increase with the increase of the angular velocity of the steering wheel turning right, the torque difference between the coaxial left and right side wheels can be flexibly determined according to the angular velocity of the steering wheel turning right, so that different emergency return intentions corresponding to different angular velocities of the steering wheel turning right can be timely responded, the vehicle body posture can be quickly corrected, the over-steering problem of the electric vehicle can be improved, and the cornering stability of the electric vehicle can be improved. For example, the more serious the over-steering of the electric vehicle turning left, the greater the original yaw trend caused by the vehicle body inertia, the greater the angular velocity of the steering wheel turning right for adjusting the steering angle, the greater the torque difference between the coaxial left and right side wheels controlled, and the greater the yaw moment opposite to the steering angle direction of the steering wheel generated by the torque difference between the coaxial left and right side wheels, so that the original yaw trend caused by the vehicle body inertia can be better offset, and the vehicle body posture can be quickly corrected.

[0072] In the embodiments of the present application, the specific control after the steering wheel turning left enters the emergency return working condition in the driving process of the electric vehicle turning right can refer to the specific control after the steering wheel turning right enters the emergency return working condition in the driving process of the electric vehicle turning left, which will not be described here.

[0073] The following will continue to be described in detail the specific control of the driving system when the angular velocity of the steering wheel turning right is greater than the preset angular velocity threshold after the steering wheel starts to turn right in the driving process of the electric vehicle turning left.

[0074] In an embodiment, the control method specifically comprises: after the second moment, controlling the driving system to increase the torque output to one left side wheel or to decrease the torque output to one right side wheel.

[0075] In the embodiment, after the electric vehicle enters the emergency return working condition, by controlling the driving system to increase the torque output to one left side wheel and / or to decrease the torque output to one right side wheel, the torque output to one left side wheel of the driving system is greater than the torque output to one right side wheel, and the yaw moment opposite to the steering angle direction of the steering wheel generated by the torque difference between the coaxial left and right side wheels can be increased, so that the yaw moment opposite to the steering angle direction of the steering wheel can offset the original yaw trend caused by the vehicle body inertia, which is beneficial to the electric vehicle to timely respond to the emergency return, to quickly correct the vehicle body posture, and to improve the cornering stability of the electric vehicle.

[0076] In an embodiment, the control method specifically comprises: after the second moment, controlling the torque difference between the torque output to one left side wheel and the torque output to one right side wheel of the driving system to be less than or equal to the torque difference threshold.

[0077] According to the tire friction circle theory, the tire grip limit is limited, and the generated yaw moment is limited. If the yaw moment generated by the torque difference between the left and right wheels of the same shaft is too large, the electric vehicle will lose stability.

[0078] In this case, by controlling the torque difference between the torque output to the left wheel and the torque output to the right wheel of the same shaft to be less than or equal to the torque difference threshold, the upper limit of the yaw moment generated by the torque difference between the left and right wheels of the same shaft is limited to avoid the electric vehicle losing stability.

[0079] In one embodiment, the greater the vertical load of the electric vehicle, the greater the control torque difference threshold.

[0080] In another embodiment, the greater the adhesion coefficient of the road surface on which the electric vehicle is located, the greater the control torque difference threshold. In this way, the torque difference threshold is optimized, the upper limit of the yaw moment that can be generated by the torque difference between the left and right wheels of the same shaft is optimized, and the accuracy of control is improved.

[0081] In this embodiment, when the angular velocity of the steering wheel to the right is greater than the preset angular velocity threshold, after detecting that the electric vehicle enters the emergency straightening condition, by controlling the torque difference between the torque output to the left wheel and the torque output to the right wheel of the same shaft to be less than or equal to the torque difference threshold, the upper limit of the yaw moment opposite to the steering angle direction generated by the torque difference between the left and right wheels of the same shaft is limited to avoid the tire grip breaking through the tire friction circle limit due to the yaw moment opposite to the steering angle direction being too large, thereby causing the electric vehicle to lose stability.

[0082] In some embodiments, when the angular velocity of the steering wheel of the electric vehicle to the right is greater than the preset angular velocity threshold, after entering the emergency straightening condition, the change in lateral acceleration of the electric vehicle causes the vertical load of each wheel to change, and the friction circle of the left and right wheels changes. The greater the lateral acceleration, the more significantly the friction circle of the left and right wheels of the same shaft shrinks.

[0083] In this case, the torque difference threshold between the left and right wheels of the same shaft is adjusted according to the lateral acceleration to improve the accuracy of control, quickly improve the stability of the electric vehicle, and suppress the fishtailing of the electric vehicle.

[0084] In this embodiment, after detecting that the electric vehicle enters the emergency straightening condition, by controlling the torque difference threshold to be less than or equal to the torque difference threshold in the case of smaller lateral acceleration, the torque difference threshold is limited according to the lateral acceleration, thereby limiting the upper limit of the yaw moment opposite to the steering angle direction generated by the torque difference between the left and right wheels of the same shaft, to avoid the electric vehicle losing stability and ensure driving safety.

[0085] In an embodiment, the control method can further comprise: after the second time, when the lateral acceleration of the electric vehicle is less than or equal to the first lateral acceleration threshold, the control torque difference threshold does not change with the increase of the lateral acceleration; when the lateral acceleration is greater than the first lateral acceleration threshold and less than or equal to the second lateral acceleration threshold, the control torque difference threshold decreases with the increase of the lateral acceleration; when the lateral acceleration is greater than the second lateral acceleration threshold and less than or equal to the third lateral acceleration threshold, the control torque difference threshold does not change with the increase of the lateral acceleration; when the lateral acceleration is greater than the third lateral acceleration threshold and less than or equal to the fourth lateral acceleration threshold, the control torque difference threshold decreases with the increase of the lateral acceleration; when the lateral acceleration is greater than the fourth lateral acceleration threshold, the control torque difference threshold does not change with the increase of the lateral acceleration.

[0086] For ease of understanding, see Figure 5 , Figure 5 A schematic diagram of the relationship between the torque difference threshold and the lateral acceleration is shown.

[0087] If the lateral acceleration is greater than 0 and less than or equal to the first lateral acceleration threshold A1, the torque difference threshold does not change with the increase of the lateral acceleration. If the lateral acceleration is greater than the first lateral acceleration threshold A1 and less than or equal to the second lateral acceleration threshold A2, the torque difference threshold decreases with the increase of the lateral acceleration. If the lateral acceleration is greater than the second lateral acceleration threshold A2 and less than or equal to the third lateral acceleration threshold A3, the torque difference threshold does not change with the increase of the lateral acceleration. If the lateral acceleration is greater than the third lateral acceleration threshold A3 and less than or equal to the fourth lateral acceleration threshold A4, the control torque difference threshold decreases with the increase of the lateral acceleration. If the lateral acceleration is greater than the fourth lateral acceleration threshold A4, the control torque difference threshold does not change with the increase of the lateral acceleration.

[0088] In the emergency return-to-normal operating condition, the first lateral acceleration threshold value, the second lateral acceleration threshold value, the third lateral acceleration threshold value, and the fourth lateral acceleration threshold value are set, the torque lateral acceleration is divided into a plurality of lateral acceleration intervals by the torque difference threshold value, and a plurality of control intervals of the torque difference threshold value are divided according to the plurality of lateral acceleration intervals. In different yaw rate intervals, the torque difference threshold value is controlled by using a corresponding control mode. For example, when the lateral acceleration is less than or equal to the first lateral acceleration threshold value, the torque difference threshold value is controlled not to change with the increase of the lateral acceleration; when the lateral acceleration is greater than the first lateral acceleration threshold value and less than or equal to the second lateral acceleration threshold value, the torque difference threshold value is controlled to decrease with the increase of the lateral acceleration; when the lateral acceleration is greater than or equal to the second lateral acceleration threshold value and less than or equal to the third lateral acceleration threshold value, the torque difference threshold value is controlled not to change with the increase of the lateral acceleration; when the lateral acceleration is greater than the third lateral acceleration threshold value and less than or equal to the fourth lateral acceleration threshold value, the torque difference threshold value is controlled to decrease with the increase of the lateral acceleration; and when the lateral acceleration is greater than the fourth lateral acceleration threshold value, the torque difference threshold value is controlled not to change with the increase of the lateral acceleration.

[0089] In this way, after detecting that the electric vehicle enters the emergency return-to-normal operating condition, the torque difference threshold value is accurately determined according to the lateral acceleration, so that the upper limit of the yaw moment generated by the torque difference between the left and right wheels of the same shaft is accurately limited, the stability of the electric vehicle is avoided, and the driving safety is ensured. For example, in the interval in which the yaw rate significantly affects the torque difference threshold value, the torque difference threshold value is controlled to decrease with the increase of the yaw rate, so as to improve the accuracy of the torque difference threshold value. In the interval in which the yaw rate does not significantly affect the torque difference threshold value, the torque difference threshold value is controlled not to change with the increase of the yaw rate, so as to reduce the control complexity of the torque difference threshold value.

[0090] In the embodiments of the present application, the fifth lateral acceleration threshold value, the sixth lateral acceleration threshold value, and other threshold values can also be set to limit the variation interval of the torque difference threshold value.

[0091] In one embodiment, the control method can further include: after the second time, controlling the torque difference threshold value to be greater than 0.

[0092] Continuing to refer to Figure 5 No matter how the lateral acceleration changes, the torque difference threshold value is always greater than 0.

[0093] In the embodiments, after the electric vehicle enters the emergency return-to-normal operating condition, by controlling the torque difference threshold value to be greater than 0, it is ensured that there is a certain operable interval between the torque differences between the left and right wheels of the same shaft, so that the yaw moment can be generated, and the stability of the electric vehicle is avoided.

[0094] In one embodiment, the control method further comprises: after the electric vehicle enters the emergency return-to-straight condition, calculating a target differential torque yaw moment required for generating a torque difference between the left and right side wheels in the same shaft according to the vehicle speed of the electric vehicle, the steering angle of the front wheels and the yaw rate.

[0095] M = Kp (y ref -y) + KI (y ref -y) dt,

[0096] wherein M refers to the differential torque yaw moment, Kp and KI refer to the proportional factor of proportional integral control, y ref refers to the expected yaw rate, y refers to the actual yaw rate.

[0097] In this embodiment, the expected yaw rate is corrected according to the yaw rate correction factor, so as to limit the yaw rate of the electric vehicle after the electric vehicle enters the emergency return-to-straight condition, limit the torque difference between the left and right side wheels in the same shaft, correct the vehicle body posture, and improve the response speed of the vehicle to the emergency return-to-straight condition while avoiding the loss of stability of the electric vehicle.

[0098]

[0099] delta sw,err = abs (delta sw,ref -delta swact ),

[0100]

[0101] wherein u refers to the vehicle speed, delta refers to the steering angle of the front wheels, L refers to the wheelbase, q refers to the yaw rate correction factor, delta sw,err refers to the angle difference of the steering wheel, delta sw,ref refers to the expected steering angle, delta sw,act refers to the actual steering angle, m refers to the vehicle weight, a refers to the distance from the front axle to the vehicle center of mass, b refers to the distance from the rear axle to the vehicle center of mass, C1 refers to the front axle cornering stiffness, C2 refers to the rear axle cornering stiffness, i sw refers to the steering ratio of the actual steering angle and the front wheel steering angle.

[0102] For ease of understanding, see Figure 6 , Figure 6 a schematic diagram showing the relationship between the yaw rate correction factor and the angle difference of the steering wheel according to the embodiments of the present application is shown.

[0103] In an embodiment, the yaw angular velocity correction factor varies with the angle difference of the steering wheel angle. After the electric vehicle enters the emergency straightening working condition, if the angle difference of the steering wheel angle is greater than 0 and less than or equal to a first angle difference threshold B1, the yaw angular velocity correction factor does not vary with the increase of the angle difference of the steering wheel angle; if the angle difference of the steering wheel angle is greater than the first angle difference threshold B1 and less than or equal to a second angle difference threshold B2, the yaw angular velocity correction factor increases with the increase of the angle difference of the steering wheel angle; if the angle difference of the steering wheel angle is greater than the second angle difference threshold B2, the yaw angular velocity correction factor does not vary with the increase of the angle difference of the steering wheel angle.

[0104] In the embodiment, by setting the first angle difference threshold and the second angle difference threshold, the yaw angular velocity correction factor is divided into different control intervals according to the angle difference of the steering wheel angle, and the yaw angular velocity correction factor adopts a corresponding control mode in different control intervals. In this way, the yaw angular velocity correction factor is accurately determined according to the angle difference of the steering wheel angle, and the torque difference of the left and right wheels coaxial with the electric vehicle is accurately limited, so as to limit the yaw moment of the electric vehicle after entering the emergency straightening working condition, quickly correct the vehicle body posture, improve the response speed of the vehicle to the emergency straightening, avoid the loss of stability of the electric vehicle, and ensure the driving safety.

[0105] After the differential torque yaw moment M is obtained, the differential torque yaw moment M is limited according to the current actual yaw angular velocity and the first yaw angular velocity threshold, the second yaw angular velocity threshold, the third yaw angular velocity threshold and the fourth yaw angular velocity threshold mentioned in the foregoing embodiments, to obtain a target differential torque yaw moment M Z .

[0106] Then, the driving motor output torques of the two rear wheels coaxial with the left and right sides of the vehicle are controlled according to the target differential torque yaw moment M Z . For example, in the scene where two front wheels share one driving motor and two rear wheels use one driving motor respectively, the torques output by the driving motor of the left rear wheel and the driving motor of the right rear wheel can be calculated according to the following calculation formula.

[0107]

[0108] Wherein, T rr is the torque output to the right rear wheel, T rl is the torque output to the left rear wheel, T tot,rear is the rear axle wheel end torque request, RdTire is the wheel radius, gearRatio is the reducer speed ratio, and tr is the rear axle wheelbase. Here, M Z is negative, T rr <T rl .

[0109] In one embodiment, the control method specifically comprises: after the second time, when the angular velocity of the steering wheel turning right is less than the first preset angular velocity, increasing the torque difference between the torque output to the left wheel and the torque output to the right wheel of the driving system with the increase of the angular velocity of the steering wheel turning right; and when the angular velocity of the steering wheel turning right is greater than or equal to the first preset angular velocity, keeping the torque difference between the torque output to the left wheel and the torque output to the right wheel of the driving system unchanged with the increase of the angular velocity of the steering wheel turning right.

[0110] In the embodiment, the greater the angular velocity of the steering wheel turning right for adjusting the steering angle after the electric vehicle enters the emergency straightening working condition, the greater the torque difference between the coaxial left and right wheels, and the greater the yaw moment generated by the torque difference between the coaxial left and right wheels in the opposite direction of the steering angle of the steering wheel, so as to quickly correct the vehicle body posture.

[0111] However, according to the tire friction circle theory, the tire grip limit is limited, and the size of the torque difference between the coaxial left and right wheels for correcting the vehicle body posture is limited. If the friction circle limit is exceeded, the electric vehicle will lose stability.

[0112] When the angular velocity of the steering wheel turning right is at the first preset angular velocity, the yaw moment generated between the tire and the ground is gradually increased when the torque difference between the coaxial left and right wheels is adjusted according to the angle difference of the steering angle, and the lateral acceleration under the yaw moment is the maximum lateral acceleration that the electric vehicle can correct the vehicle body posture and avoid the tendency of the electric vehicle to spin out within the tire grip limit through the torque difference between the coaxial left and right wheels.

[0113] When the angular velocity of the steering wheel turning right is less than or equal to the first preset angular velocity, the steering wheel straightening speed is relatively gentle, indicating that the lateral acceleration corresponding to the yaw moment generated by the torque difference between the coaxial left and right wheels is within the tire grip limit in the process of correcting the vehicle body posture and avoiding the tendency of the electric vehicle to spin out; and when the angular velocity of the steering wheel turning right is greater than the first preset angular velocity, the steering wheel straightening speed is relatively fast, indicating that the lateral acceleration corresponding to the yaw moment generated by the torque difference between the coaxial left and right wheels may exceed the tire grip limit in the process of correcting the vehicle body posture and avoiding the tendency of the electric vehicle to spin out.

[0114] In the case that the angular velocity of the steering wheel turning right is less than or equal to the first preset angular velocity, the torque difference between the torque output by the control driving system to one left wheel and the torque output by the control driving system to one right wheel is increased with the increase of the angular velocity of the steering wheel turning right, so that the torque difference between the coaxial left and right wheels is flexibly determined according to the lateral acceleration, and the yaw moment generated by the torque difference is enough to quickly correct the vehicle body posture and avoid the tendency of the electric vehicle to spin out.

[0115] In the case that the angular velocity of the steering wheel turning right is greater than the first preset angular velocity, the torque difference between the torque output by the control driving system to one left wheel and the torque output by the control driving system to one right wheel does not change with the increase of the angular velocity of the steering wheel turning right, so as to ensure that the yaw moment generated by the torque difference between the coaxial left and right wheels does not break through the tire grip limit.

[0116] In an embodiment, the control method can further include: in the case that the angular velocity of the steering wheel turning right is greater than the first preset angular velocity, the torque difference between the torque output by the control driving system to one left wheel and the torque output by the control driving system to one right wheel is a preset torque difference.

[0117] The preset torque difference can be a torque difference corresponding to a preset lateral acceleration, and the preset torque difference can also be slightly less than the torque difference corresponding to the preset lateral acceleration.

[0118] Referring to Figure 5 , Figure 5 In the case that the lateral acceleration is in the four intervals of [0, A1], [A2, A3], [A3, A4] and [A4, +∞], the preset lateral acceleration is different, the preset torque difference corresponding to the preset lateral acceleration is different, and the preset torque difference is different.

[0119] In an embodiment, the control method specifically includes: after the first time and before the second time, the opening degree of the accelerator pedal of the electric vehicle is a first accelerator pedal opening degree, and the torque sum output by the control driving system to the electric vehicle is a first torque sum; after the second time, the opening degree of the accelerator pedal is the first accelerator pedal opening degree, and the torque sum output by the control driving system to the electric vehicle is reduced to be less than the first torque sum.

[0120] The torque sum indicated by the opening degree of the accelerator pedal refers to the sum of the torques indicated by the torque signals corresponding to each wheel of the driving system after the accelerator pedal is operated. The first torque sum is the torque sum indicated by the first accelerator pedal opening degree.

[0121] In the embodiment, after the electric vehicle enters the emergency return-to-straight condition, the acceleration of the electric vehicle is relatively large, which can cause the grip of the wheels to break through the limit of the friction circle. By controlling the torque of the electric vehicle to be less than the first torque indicated by the opening degree of the first accelerator pedal, i.e., by controlling the drive system to actively reduce the torque, the acceleration of the electric vehicle after entering the emergency return-to-straight condition is limited, the response speed of the vehicle to the emergency return-to-straight condition is improved, the stability of the electric vehicle is avoided, and the driving safety is ensured.

[0122] In an embodiment, the control method specifically comprises: after the second time, the greater the opening degree of the first accelerator pedal, the greater the reduction amount of the torque output by the drive system to the electric vehicle.

[0123] In the embodiment, after the electric vehicle enters the emergency return-to-straight condition, the greater the opening degree of the first accelerator pedal, the greater the total wheel-end torque request of the electric vehicle, and the greater the acceleration of the electric vehicle, and the more likely the electric vehicle to lose stability during acceleration.

[0124] In this case, the greater the reduction amount of the torque output by the drive system to the electric vehicle, the greater the strength of actively controlling the drive system to reduce the torque, the greater the strength of limiting the acceleration of the electric vehicle after entering the emergency return-to-straight condition, and the size of the torque reduction amount is flexibly determined according to the size of the first accelerator pedal opening degree, so as to accurately control the strength of the drive system to reduce the torque under different first accelerator pedal opening degrees, ensure the stability of the electric vehicle, and ensure the driving safety.

[0125] In an embodiment, if the opening degree of the first accelerator pedal is less than the preset accelerator pedal opening degree, the torque output by the drive system to the electric vehicle after the electric vehicle enters the emergency return-to-straight condition is equal to the first torque. That is, in the case that the acceleration of the electric vehicle is relatively small, by controlling the torque output by the drive system to the electric vehicle to be equal to the first torque after the electric vehicle enters the emergency return-to-straight condition, the normal driving of the electric vehicle during the emergency return-to-straight condition is ensured.

[0126] In an embodiment, the control method specifically comprises: after the second time, when the yaw angular velocity of the electric vehicle is a first yaw angular velocity, the torque difference between the torque output by the drive system to one left wheel or the torque output by the drive system to one right wheel and the torque indicated by the opening degree of the accelerator pedal is a first torque difference; when the yaw angular velocity is a second yaw angular velocity greater than the first yaw angular velocity, the torque difference between the torque output by the drive system to one left wheel or the torque output by the drive system to one right wheel and the torque indicated by the opening degree of the accelerator pedal is a second torque difference, and the second torque difference is greater than the first torque difference.

[0127] In the embodiment, the greater the opening degree of the accelerator pedal, the greater the total wheel end torque request of the electric vehicle, and the greater the acceleration of the electric vehicle after the electric vehicle enters the emergency return-to-straight condition. At this time, the greater the yaw rate, the more likely the electric vehicle is to lose stability during acceleration.

[0128] In this case, by controlling the torque of the electric vehicle and the difference between the torque indicated by the opening degree of the accelerator pedal, the greater the yaw rate of the electric vehicle, the greater the limiting degree of the torque of the electric vehicle, and the greater the yaw rate, the greater the limiting degree of the torque of the electric vehicle, thereby limiting the acceleration of the electric vehicle after the electric vehicle enters the emergency return-to-straight condition, which is conducive to timely responding to the emergency return-to-straight condition while better ensuring the stability of the electric vehicle and ensuring driving safety.

[0129] In the embodiment, by controlling the torque difference between the torque output by the drive system to the left or right wheel and the torque indicated by the opening degree of the accelerator pedal to be greater when the yaw rate is greater, and to be smaller when the yaw rate is smaller, the torque output by the drive system to the left or right wheel is accurately limited according to the yaw rate and the opening degree of the accelerator pedal, thereby accurately limiting the acceleration of the electric vehicle according to the yaw rate and the opening degree of the accelerator pedal, and better helping to timely respond to the emergency return-to-straight condition while ensuring the stability of the electric vehicle and ensuring driving safety.

[0130] In one embodiment, the control method specifically comprises: after the second time, when the yaw rate of the electric vehicle is greater than the preset yaw rate, the sum of the torque output by the drive system to one left wheel and the torque output to one right wheel decreases with the increase of the yaw rate; when the yaw rate of the electric vehicle is less than or equal to the preset yaw rate, the sum of the torque output by the drive system to one left wheel and the torque output to one right wheel does not change with the increase of the yaw rate.

[0131] In some embodiments, during the driving process of the electric vehicle turning left, the electric vehicle is in an emergency return-to-straight condition, the greater the yaw rate, the greater the original yaw tendency caused by the body inertia, and the more likely the electric vehicle is to lose stability. When the electric vehicle is in the emergency return-to-straight condition, if the yaw rate of the electric vehicle is greater than the preset yaw rate, the body is on the edge of losing control, and the electric vehicle may spin; if the yaw rate of the electric vehicle is less than or equal to the preset yaw rate, the body is not on the edge of losing control.

[0132] In this case, in the case that the yaw rate of the electric vehicle is less than or equal to the preset yaw rate, the sum of the torque output to the left wheel and the torque output to the right wheel of the drive system does not change with the increase of the yaw rate. In the case that the yaw rate of the electric vehicle is greater than the preset yaw rate, the sum of the torque output to the left wheel and the torque output to the right wheel of the drive system decreases with the increase of the yaw rate. In this way, in the case that the electric vehicle is likely to spin, by reducing the sum of the torques of the coaxial left and right wheels of the electric vehicle, the acceleration of the electric vehicle is reduced, the original yaw tendency caused by the vehicle body inertia is reduced, the spin of the electric vehicle is inhibited, and the stability of the electric vehicle is avoided. Moreover, by reducing the sum of the torques of the coaxial left and right wheels of the electric vehicle, the original yaw tendency caused by the vehicle body inertia is reduced, the resistance of the vehicle body inertia to the correction of the vehicle body posture is weakened, and the response speed of the vehicle to the emergency return is improved.

[0133] In the embodiment, the sum of the torques of the electric vehicle is corrected according to the torque correction factor, so that after the electric vehicle enters the emergency return working condition, by limiting the sum of the torques of the electric vehicle, the original yaw tendency caused by the vehicle body inertia is reduced, the resistance of the vehicle body inertia to the correction of the vehicle body posture is weakened, and the response speed of the vehicle to the emergency return is improved.

[0134] In one embodiment, the control method can further specifically include: after the second time, correcting the rear axle wheel end torque request according to a torque correction factor to obtain a target rear axle wheel end torque request, wherein the torque correction factor changes with the change of the yaw rate.

[0135] The calculation formula for correcting the rear axle wheel end torque request according to the torque correction factor is as follows:

[0136] T tot,rear,coorn = T tot,rear * p,

[0137] wherein T tot,rear,coorn is the target rear axle wheel end torque request, T tot,rear is the rear axle wheel end torque request, and p is the torque correction factor.

[0138] Correspondingly,

[0139] In the embodiment, the rear axle wheel end torque request is corrected according to the torque correction factor, so that after the electric vehicle enters the emergency return working condition, by limiting the sum of the torques of the electric vehicle, the acceleration of the electric vehicle is reduced, the original yaw tendency caused by the vehicle body inertia is reduced, the resistance of the vehicle body inertia to the correction of the vehicle body posture is weakened, and the response speed of the vehicle to the emergency return is improved.

[0140] For ease of understanding, seeFigure 7 , Figure 7 A schematic diagram of the relationship between the torque correction factor and the yaw rate is shown.

[0141] In this embodiment, if the yaw rate is greater than 0 and less than or equal to a first yaw rate threshold D1 (the first yaw rate threshold can be a preset yaw rate), the torque correction factor does not change with the increase of the yaw rate; if the yaw rate is greater than the first yaw rate threshold D1 and less than or equal to a second yaw rate threshold D2, the torque correction factor decreases with the increase of the yaw rate; and if the yaw rate is greater than the second yaw rate threshold D2, the torque correction factor does not change with the increase of the yaw rate.

[0142] After the electric vehicle enters the emergency return-to-straight condition, by setting the first yaw rate threshold and the second yaw rate threshold, the torque correction factor is divided into different control intervals according to the yaw rate, and the torque correction factor adopts a corresponding control mode in different control intervals. In this way, the torque correction factor is accurately determined according to the yaw rate, the torque of the electric vehicle is accurately limited, the acceleration of the electric vehicle after entering the emergency return-to-straight condition is limited, the original yaw trend caused by the vehicle body inertia is reduced, the resistance of the vehicle body inertia to the correction of the vehicle body posture is weakened, and the response speed of the vehicle to the emergency return-to-straight is improved.

[0143] In the embodiments of the present application, a third yaw rate threshold, a fourth yaw rate threshold, and the like can also be set to limit the variation interval of the torque correction factor.

[0144] In one embodiment, the control method specifically comprises: after the second time, the greater the steering angle of the steering wheel to the left, the greater the torque difference between the torque output by the driving system to one left wheel and the torque output to one right wheel.

[0145] After the second time when the steering wheel starts to turn to the right, if the greater the steering angle of the steering wheel to the left, the more serious the over-steering degree of the electric vehicle to the left, and the greater the original yaw trend caused by the vehicle body inertia, the electric vehicle is more likely to lose stability when the electric vehicle enters the emergency return-to-straight condition.

[0146] In this case, by increasing the torque difference between the torque output by the driving system to one left wheel and the torque output to one right wheel, the yaw moment in the opposite direction of the steering angle of the steering wheel generated by the torque difference between the coaxial left and right wheels can help to respond to the emergency return-to-straight intention in time in the case of serious over-steering of the vehicle to the left, offset the original yaw trend caused by the vehicle body inertia, correct the vehicle body posture, and improve the cornering stability of the electric vehicle.

[0147] In the embodiment, when the electric vehicle enters the emergency return-to-straight condition, the greater the steering wheel turning angle to the left, the greater the original yaw tendency caused by the vehicle body inertia, and the more likely the electric vehicle loses stability. In this case, the greater the torque difference between the torque output by the drive system to one left wheel and the torque output to one right wheel, the greater the yaw moment opposite to the steering wheel turning direction generated by the torque difference between the coaxial left and right wheels, which can help to respond to the emergency return-to-straight intention in time in the case that the vehicle turns to the left excessively, offset the original yaw tendency caused by the vehicle body inertia, correct the vehicle body posture, and improve the cornering stability of the electric vehicle.

[0148] In an embodiment, the control method specifically comprises: after the second time, the greater the vehicle speed of the electric vehicle, the greater the torque difference between the torque output by the drive system to one left wheel and the torque output to one right wheel.

[0149] When the electric vehicle enters the emergency return-to-straight condition, the greater the vehicle speed of the electric vehicle, the greater the original yaw tendency caused by the vehicle body inertia, and the more likely the electric vehicle loses stability.

[0150] In this case, the greater the torque difference between the torque output by the drive system to one left wheel and the torque output to one right wheel, the greater the yaw moment opposite to the steering wheel turning direction generated by the torque difference between the coaxial left and right wheels, which can offset the original yaw tendency caused by the vehicle body inertia, correct the vehicle body posture, and improve the cornering stability of the electric vehicle.

[0151] In the embodiment, when the electric vehicle enters the emergency return-to-straight condition, the greater the vehicle speed of the electric vehicle, the greater the original yaw tendency caused by the vehicle body inertia, and the more likely the electric vehicle loses stability. In this case, the greater the torque difference between the torque output by the drive system to one left wheel and the torque output to one right wheel, the greater the yaw moment opposite to the steering wheel turning direction generated by the torque difference between the coaxial left and right wheels, which can help to respond to the emergency return-to-straight in time in different vehicle speeds, offset the original yaw tendency caused by the vehicle body inertia, correct the vehicle body posture, and improve the cornering stability of the electric vehicle.

[0152] The embodiment of the application provides a vehicle controller, which is used to execute the control method for the cornering of the electric vehicle provided in the above embodiments.

[0153] The vehicle controller is specifically configured to: during driving of the electric vehicle turning left, after a first time point at which the steering wheel starts to turn left, before a second time point at which the steering wheel starts to turn right, control the driving system to output a torque to a left wheel smaller than a torque output to a right wheel; after the second time point, when the angular velocity of the steering wheel turning right is greater than a preset angular velocity threshold, control the driving system to output a torque to the left wheel greater than a torque output to the right wheel, and control the torque difference between the torque output to the left wheel and the torque output to the right wheel to increase with the increase of the angular velocity of the steering wheel turning right.

[0154] In the embodiment, during driving of the electric vehicle turning left, the vehicle controller controls the driving system to output a torque to a left wheel coaxial with the left wheel smaller than a torque output to a right wheel, so that a torque difference between the left and right wheels generates a yaw moment in the same direction as the steering wheel, thereby assisting the electric vehicle to turn left. When it is detected that the steering wheel starts to turn right and the angular velocity of the steering wheel turning right is greater than a preset angular velocity threshold, it is detected that the electric vehicle enters an emergency straightening condition. In this case, the vehicle controller controls the driving system to output a torque to the left wheel coaxial with the left wheel greater than a torque output to the right wheel, so that a torque difference between the left and right wheels coaxial with the left wheel generates a yaw moment in the opposite direction of the steering wheel, thereby offsetting the original yaw trend caused by the vehicle body inertia, quickly correcting the vehicle body posture, and improving the response speed of the emergency straightening. Moreover, the vehicle controller controls the torque difference between the torque output to the left wheel and the torque output to the right wheel to increase with the increase of the angular velocity of the steering wheel turning right, thereby flexibly determining the torque difference between the left and right wheels coaxial with the left wheel according to the angular velocity of the steering wheel turning right, so as to timely respond to different emergency straightening intentions corresponding to different angular velocities of the steering wheel turning right, quickly correct the vehicle body posture, improve the over-steering problem of the electric vehicle, and improve the cornering stability of the electric vehicle. For example, the more serious the over-steering of the electric vehicle turning left, the greater the original yaw trend caused by the vehicle body inertia, and the greater the angular velocity of the steering wheel turning right for adjusting the steering angle, and the greater the torque difference between the left and right wheels coaxial with the left wheel, so that the yaw moment generated by the torque difference between the left and right wheels coaxial with the left wheel in the opposite direction of the steering wheel is greater, thereby better offsetting the original yaw trend caused by the vehicle body inertia, and quickly correcting the vehicle body posture.

[0155] In an embodiment, the vehicle controller is a motor controller, during the driving of the electric vehicle turning left, after a first time point at which the steering wheel starts to turn left, before a second time point at which the steering wheel starts to turn right, the motor controller controls the driving system to output a torque to a left wheel smaller than a torque output to a right wheel; after the second time point, the angular velocity of the steering wheel to the right is greater than a preset angular velocity threshold, the motor controller controls the driving system to output a torque to a left wheel greater than a torque output to a right wheel, and controls the torque difference between the torque output to a left wheel and the torque output to a right wheel to increase with the increase of the angular velocity of the steering wheel to the right.

[0156] For ease of understanding, refer to Figure 8 , Figure 8 A schematic diagram of a motor controller provided by an embodiment of the application is shown.

[0157] As shown in Figure 8 , the motor controller receives a steering wheel signal, an inertial measurement unit (IMU) signal, an accelerator pedal signal and a vehicle speed signal, and determines whether the electric vehicle enters an emergency straightening condition according to the received signals, and actively controls the driving motor output torque after determining that the electric vehicle enters the emergency straightening condition.

[0158] The steering wheel signal includes the angle and direction of the steering wheel rotation and the steering wheel angular velocity, and the IMU signal includes the lateral acceleration and yaw angular velocity of the electric vehicle.

[0159] In this embodiment, the motor controller can identify whether the angular velocity of the steering wheel to the right is greater than a preset angular velocity threshold, and determine that the electric vehicle enters the emergency straightening condition when the angular velocity of the steering wheel to the right is greater than the preset angular velocity threshold. After determining that the angular velocity of the steering wheel to the right is greater than the preset angular velocity threshold, the motor controller directly controls the driving system to output a torque to a left wheel coaxial with the electric vehicle greater than a torque output to a right wheel, rather than controlling the driving system to adjust the torque output in response to receiving a torque signal sent by other controllers to the motor controller, so as to shorten the control chain of the electric vehicle.

[0160] In another embodiment, the vehicle controller is a vehicle controller, the vehicle controller outputs a torque signal to each motor controller, each motor controller controls a corresponding drive motor to output torque to a corresponding wheel, wherein after a first time when the steering wheel starts to turn left and before a second time when the steering wheel starts to turn right, the torque output by the drive system to one left wheel is less than the torque output to one right wheel; after the second time, the angular velocity of the steering wheel to the right is greater than a preset angular velocity threshold, the torque output by the drive system to one left wheel is greater than the torque output to one right wheel, and the torque difference between the torque output to one left wheel and the torque output to one right wheel increases with the increase of the angular velocity of the steering wheel to the right.

[0161] For ease of understanding, refer to Figure 9 , Figure 9 A schematic diagram of a vehicle controller provided by an embodiment of the application is shown.

[0162] As shown in Figure 9 , the vehicle controller receives a steering wheel signal, an inertial measurement unit (IMU) signal, an accelerator pedal signal and a vehicle speed signal, and determines whether the angular velocity of the steering wheel to the right is greater than a preset angular velocity threshold according to the received signals, and determines that the electric vehicle enters an emergency straightening condition when the angular velocity of the steering wheel to the right is greater than the preset angular velocity threshold. After determining that the angular velocity of the steering wheel to the right is greater than the preset angular velocity threshold, a torque signal is output to the motor controller, and each drive motor outputs torque according to the torque indicated by the torque signal.

[0163] In this embodiment, the vehicle controller can also issue a torque signal to the motor controller after the angular velocity of the steering wheel to the right is greater than the preset angular velocity threshold to control the drive system to output torque to one left wheel of the electric vehicle coaxial with the electric vehicle, which is less than the torque output to one right wheel of the electric vehicle. The control of the vehicle controller and the control of the motor controller achieve redundancy backup.

[0164] In one embodiment, the vehicle controller is specifically configured to: after the second time, the yaw angular velocity of the electric vehicle is greater than a preset yaw angular velocity, the sum of the torque output by the drive system to one left wheel and the torque output to one right wheel decreases with the increase of the yaw angular velocity of the electric vehicle; the yaw angular velocity of the electric vehicle is less than or equal to the preset yaw angular velocity, the sum of the torque output by the drive system to one left wheel and the torque output to one right wheel does not change with the increase of the yaw angular velocity of the electric vehicle.

[0165] In the embodiment, after the electric vehicle enters the emergency return-to-straight condition, the vehicle controller controls the sum of the torque output by the driving system to a left wheel and the torque output to a right wheel according to the yaw rate. When the yaw rate is greater than a preset yaw rate, i.e., the electric vehicle is likely to spin, the acceleration of the electric vehicle is reduced by reducing the sum of the torques of the coaxial left and right wheels of the electric vehicle, the original yaw trend caused by the inertia of the vehicle body is reduced, the spin of the electric vehicle is inhibited, and the stability of the electric vehicle is avoided. Moreover, by reducing the sum of the torques of the coaxial left and right wheels of the electric vehicle, the original yaw trend caused by the inertia of the vehicle body is reduced, the resistance of the inertia of the vehicle body to the correction of the vehicle body posture is weakened, and the response speed of the vehicle to the emergency return-to-straight is improved.

[0166] Similarly, the vehicle controller can be a motor controller or a vehicle controller.

[0167] It can be understood that all related contents involved in the above method embodiments can be cited into the embodiments of the controller, and details are not described herein again.

[0168] In another embodiment of the application, an electric vehicle is also provided, which comprises a driving system and wheels, and the driving system comprises a vehicle controller configured to control the torque output by the driving system to the wheels.

[0169] The vehicle controller is specifically configured to: during the driving process of the electric vehicle turning left, control the torque output by the driving system to a left wheel to be less than the torque output to a right wheel after a first time when the steering wheel starts to turn left and before a second time when the steering wheel starts to turn right; and after the second time, when the angular velocity of the steering wheel turning right is greater than a preset angular velocity threshold, control the torque output by the driving system to the left wheel to be greater than the torque output to the right wheel, and control the torque difference between the torque output to the left wheel and the torque output to the right wheel to increase with the increase of the angular velocity of the steering wheel turning right.

[0170] It can be understood that all related contents involved in the above method embodiments and vehicle controller embodiments can be cited into the embodiments of the electric vehicle, and details are not described herein again.

[0171] Finally, it should be noted that: the above is only a specific implementation of the present application, but the protection scope of the present application is not limited to this, any change or replacement within the technical scope disclosed in the present application should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A control method of an electric vehicle passing a curve, characterized by, The control method is used for controlling the drive system of the electric vehicle to adjust the torques output to a left wheel and a right wheel coaxial with each other to improve the cornering stability of the electric vehicle during cornering driving of the electric vehicle, and the control method comprises: during the cornering driving of the electric vehicle to the left, after a first time when the steering wheel starts to turn to the left and before a second time when the steering wheel starts to turn to the right, controlling the torque output to the left wheel by the drive system to be less than the torque output to the right wheel; after the second time, the angular velocity of the steering wheel to the right is greater than a preset angular velocity threshold, the torque output to the left wheel by the drive system is controlled to be greater than the torque output to the right wheel, and the torque difference between the torque output to the left wheel and the torque output to the right wheel is controlled to increase with the increase of the angular velocity of the steering wheel to the right.

2. The control method according to claim 1, characterized by, The control method specifically comprises: after the second time, the yaw angular velocity of the electric vehicle is greater than a preset yaw angular velocity, the sum of the torque output to the left wheel and the torque output to the right wheel by the drive system is controlled to decrease with the increase of the yaw angular velocity; the yaw angular velocity of the electric vehicle is less than or equal to the preset yaw angular velocity, and the sum of the torque output to the left wheel and the torque output to the right wheel by the drive system is not controlled to change with the increase of the yaw angular velocity.

3. The control method according to claim 1, characterized by, The control method specifically comprises: after the second time, the torque difference between the torque output to the left wheel and the torque output to the right wheel by the drive system is controlled to be less than or equal to a torque difference threshold.

4. The control method according to any one of claims 1 to 3, characterized by, The control method specifically comprises: after the second time, the angular velocity of the steering wheel to the right is less than a first preset angular velocity, the torque difference between the torque output to the left wheel and the torque output to the right wheel by the drive system is controlled to increase with the increase of the angular velocity of the steering wheel to the right; the angular velocity of the steering wheel to the right is greater than or equal to the first preset angular velocity, and the torque difference between the torque output to the left wheel and the torque output to the right wheel by the drive system is not controlled to change with the increase of the angular velocity of the steering wheel to the right.

5. The control method according to any one of claims 1 to 3, characterized by, The control method specifically comprises: after the first time and before the second time, the opening degree of an accelerator pedal of the electric vehicle is a first accelerator pedal opening degree, and the torque sum output to the electric vehicle by the drive system is a first torque sum; after the second time, the opening degree of the accelerator pedal is the first accelerator pedal opening degree, and the torque sum output to the electric vehicle by the drive system is controlled to decrease to be less than the first torque sum.

6. The control method according to claim 5, characterized by The control method specifically comprises: after the second time, the greater the first accelerator pedal opening degree, the greater the amount of decrease of the torque sum output to the electric vehicle by the drive system.

7. The control method according to any one of claims 1 to 3, characterized by, The control method specifically comprises: After the second time, the yaw angular velocity of the electric vehicle is a first yaw angular velocity, and a torque difference between a torque output by the drive system to the one left-side wheel or a torque output by the drive system to the one right-side wheel and a torque indicated by an opening degree of an accelerator pedal is a first torque difference; The yaw angular velocity is a second yaw angular velocity greater than the first yaw angular velocity, and a torque difference between a torque output by the drive system to the one left-side wheel or a torque output by the drive system to the one right-side wheel and a torque indicated by the opening degree of the accelerator pedal is a second torque difference, the second torque difference being greater than the first torque difference.

8. The control method according to any one of claims 1 to 3, characterized by, The control method specifically comprises: After the second time, the drive system is controlled to increase the torque output to the one left-side wheel or to decrease the torque output to the one right-side wheel.

9. The control method according to any one of claims 1 to 3, characterized by, The control method specifically comprises: After the second time, the greater the turning angle of the steering wheel to the left, the greater the torque difference between the torque output by the drive system to the one left-side wheel and the torque output by the drive system to the one right-side wheel.

10. The control method according to any one of claims 1 to 3, characterized by, The control method specifically comprises: After the second time, the greater the vehicle speed of the electric vehicle, the greater the torque difference between the torque output by the drive system to the one left-side wheel and the torque output by the drive system to the one right-side wheel.

11. A vehicle controller characterized by comprising: The vehicle controller is configured to control a drive system of an electric vehicle, and the vehicle controller is configured to: During left turning of the electric vehicle, after a first time when a steering wheel starts to turn to the left and before a second time when the steering wheel starts to turn to the right, a torque output by the drive system to one left-side wheel is less than a torque output by the drive system to one right-side wheel, the one left-side wheel and the one right-side wheel being coaxial wheels; After the second time, when an angular velocity of the steering wheel to the right is greater than a preset angular velocity threshold, the torque output by the drive system to the one left-side wheel is greater than the torque output by the drive system to the one right-side wheel, and a torque difference between the torque output to the one left-side wheel and the torque output to the one right-side wheel is controlled to increase with an increase of the angular velocity of the steering wheel to the right.

12. The vehicle controller of claim 11, wherein, The vehicle controller is specifically configured to: After the second time, when a yaw angular velocity of the electric vehicle is greater than a preset yaw angular velocity, a sum of the torque output by the drive system to the one left-side wheel and the torque output by the drive system to the one right-side wheel is controlled to decrease with an increase of the yaw angular velocity of the electric vehicle; When the yaw angular velocity of the electric vehicle is less than or equal to the preset yaw angular velocity, the sum of the torque output by the drive system to the one left-side wheel and the torque output by the drive system to the one right-side wheel is not controlled to change with an increase of the yaw angular velocity of the electric vehicle.

13. An electric vehicle characterized by comprising: The electric vehicle comprises a drive system and wheels, the drive system comprising a vehicle controller configured to control torque output by the drive system to the wheels, and the vehicle controller is specifically configured to: In the driving process of the electric vehicle turning left, after a first moment when the steering wheel starts to turn left, before a second moment when the steering wheel starts to turn right, the control system controls the driving system to output a torque to a left wheel smaller than a torque output to a right wheel, the left wheel and the right wheel being coaxial wheels; After the second moment, the angular velocity of the steering wheel to the right is greater than a preset angular velocity threshold, the control system controls the driving system to output a torque to the left wheel greater than a torque output to the right wheel, and controls the torque difference between the torque output to the left wheel and the torque output to the right wheel to increase with the increase of the angular velocity of the steering wheel to the right.

Images