Control method for an electric vehicle, vehicle controller and electric vehicle

Abstract

The application discloses a control method for reducing cornering roll, a vehicle controller and an electric vehicle, relates to the field of new energy vehicles, and can be applied to pure electric vehicles and hybrid vehicles. The control method comprises the following steps: increasing the steering wheel angle of the electric vehicle from zero at a first time, increasing the output torque of the active lateral stabilizer of the electric vehicle, and increasing the difference between the driving torque of a left wheel and the driving torque of a right wheel of the electric vehicle. At a second time after the first time, the steering wheel angle of the electric vehicle is increased from less than a preset steering angle to equal to or greater than the preset steering angle, the output torque of the active lateral stabilizer is reduced, and the difference between the driving torque of the left wheel and the driving torque of the right wheel is reduced. According to the scheme, the roll angle of the vehicle body during cornering can be reduced, the vehicle body control capability is improved, the system robustness is improved, and the driving experience and safety of the vehicle are improved.

Description

Technical Field

[0001] This application relates to the field of new energy vehicles, and more specifically, to a control method for reducing cornering roll, a vehicle controller, and an electric vehicle. Background Technology

[0002] Excessive lateral swaying or rolling of the vehicle during operation can cause discomfort to passengers. Severe body roll, such as during sharp turns at high speeds, can trigger a rollover, resulting in injury or death. When making sharp turns at intersections, significant body roll occurs, causing occupants to lean and impacting driving comfort and confidence. On wet or slippery surfaces, sharp turns at intersections can lead to wheel slippage, causing the vehicle to fishtail and wobble. Large axle load transfer results in tire friction loss, particularly lateral force loss, affecting steering performance, increasing driver input frequency, reducing lateral acceleration limits, and ultimately decreasing safety margins.

[0003] Existing stabilizer bars typically include passive and active stabilizers. However, passive stabilizers cannot be actively adjusted, and body roll cannot be optimized. Active stabilizers control body roll based on the roll angle, but sampling and estimating the roll angle using body roll sensors are difficult, resulting in inaccurate system control and poor robustness.

[0004] Therefore, how to reduce the body roll of electric vehicles when turning is a problem that needs to be solved. Summary of the Invention

[0005] This application provides a control method for reducing cornering roll. The vehicle controller and electric vehicle reduce the body roll angle during cornering by coordinating active lateral stabilizer bar control with yaw rate stabilization control, greatly improving vehicle control capability, maximizing tire lateral force, providing directional stability, enhancing system robustness, and improving the driving experience and safety of the vehicle.

[0006] Firstly, this application provides a control method for an electric vehicle, used to control the electric vehicle to reduce cornering roll during cornering. The control method includes, at a first moment, increasing the steering wheel angle of the electric vehicle from zero, increasing the torque output of the active anti-roll bar, and increasing the difference between the drive torque of one left wheel and the drive torque of one right wheel on the same axle. At a second moment after the first moment, the steering wheel angle of the electric vehicle increases from less than a preset angle to equal to or greater than a preset angle, decreasing the torque output of the active anti-roll bar, and decreasing the difference between the drive torque of one left wheel and the drive torque of one right wheel.

[0007] This electric vehicle is equipped with an active stabilizer bar. The active stabilizer bar includes an actuator and a stabilizer bar; the actuator supplies torque to the stabilizer bar to cause it to twist. The electric vehicle includes multiple drive motors, each driving multiple wheels.

[0008] When an electric vehicle is turning, it experiences lateral acceleration, causing the vehicle to tilt around its lateral axis and creating a height difference between the left and right sides. Excessive lateral swaying or rolling can cause discomfort to the driver and passengers, while significant body roll will cause the occupants to lean with the vehicle, affecting driving comfort and confidence.

[0009] In vehicles with traditional passive anti-roll bars, the roll moment is borne by the passive anti-roll bar and springs. When turning, the outer spring is compressed and the inner spring is stretched. The outer rocker arm of the passive anti-roll bar is thus pressed down, and the resulting torque is transmitted to the inner rocker arm, pulling the inner side of the body down as well, thereby reducing the body roll to the outside.

[0010] Compared to passive stabilizer bars, active roll control (ARC) adds actuators, allowing for the adjustment of vehicle attitude through active control of these actuators. The actuators can be hydraulic or electric. The stabilizer bar can consist of one or more components. Active roll control can generate a real-time adjustable anti-roll torque through active actuation. For example, when an electric vehicle turns left, due to centrifugal force, the vehicle body tilts outward (to the right). The actuators of the active roll control output torque, causing equal and opposite torques to be generated on both the left and right sides of the stabilizer bar, collectively producing a counter-clockwise anti-roll torque on the vehicle body, thereby reducing body roll. This application does not specifically limit the structural form, power source, or installation method of the active roll control.

[0011] It should be understood that the control of the active lateral stabilizer bar can be performed by the motor controller, vehicle controller, or other separately configured controllers with control capabilities. These controllers can be connected to the active lateral stabilizer bar via a controller area network (CAN) bus, local interconnect network (LIN) bus, high-speed fault-tolerant network protocol (FlexRay) bus, or other wired or wireless connection methods, and exchange signals.

[0012] The coaxial left and right wheels in this application can be left and right side wheels and right rear wheel, or left front wheel and right front wheel.

[0013] When an electric vehicle is in motion, as the steering wheel angle increases and the vehicle turns, it experiences lateral acceleration. Lateral acceleration refers to the acceleration component perpendicular to the vehicle's velocity direction when turning; it can also be called transverse acceleration.

[0014] When electric vehicles turn at high speeds or large angles, the centrifugal force caused by the turn results in a roll angle, which leads to load transfer. Significant load transfer results in tire friction limit circle loss, particularly lateral force loss, affecting steering performance. Simultaneously, the adjustment of the roll angle by the active stabilizer bar alters the vertical load on the tires, indirectly affecting the vehicle's yaw stability.

[0015] Yaw acceleration is the acceleration of an electric vehicle's body around its vertical axis during cornering. Yaw acceleration is affected by the vehicle's speed and cornering angle. As speed increases, the vehicle needs to generate greater centrifugal force to overcome inertia during cornering, resulting in a corresponding increase in yaw acceleration. Yaw acceleration is generally proportional to lateral acceleration. To ensure lateral force on the tires and provide directional stability, yaw control can be achieved by generating a torque vector through the drive motor.

[0016] Yaw control can be achieved through a motor controller or a vehicle controller. The motor controller can be applicable to electric or hybrid vehicles, where the electric vehicle can have a distributed or centralized motor architecture with multiple drive motors and multiple motor controllers, which can be any one of the multiple motor controllers. The vehicle controller can send torque signals to multiple motor controllers, thereby controlling the drive motors to output the torque indicated by the torque signal.

[0017] When the torque output by the drive motor driving the left wheel is different from the torque output by the drive motor driving the right wheel, the electric vehicle will generate a lateral force due to the torque. The difference between the torque output by the drive motor driving the left wheel and the torque output by the drive motor driving the right wheel can be controlled by adjusting the torque output by the multiple drive motors.

[0018] At the second moment, when the steering wheel angle of the electric vehicle stabilizes during cornering, the torque output of the active stabilizer bar actuator reaches its peak, and the difference between the drive torque of the left and right wheels also reaches its peak. During cornering, roll angle overshoot occurs. Overshoot refers to a change in roll angle exceeding its final stable value, followed by a return to and stabilization near that value. This can cause passenger discomfort and even affect vehicle stability and safety. Roll angle overshoot typically occurs at the moment the steering wheel angle stabilizes, i.e., the second moment. Therefore, by adjusting the torque of the stabilizer bar actuator and the yaw torque of the drive motor to reach their peak at the second moment, roll angle overshoot can be effectively suppressed, improving passenger comfort.

[0019] According to the solution in this application, the torque vector generated by the actuator of the active lateral stabilizer bar is controlled in coordination with the drive motor to reduce the roll angle of the vehicle body, maximize the lateral force of the tires, provide directional stability, and improve the driving experience and safety of the vehicle.

[0020] In conjunction with the first aspect, in some implementations of the first aspect, the control method further includes, at a third time point after the second time point, when the steering wheel angle is less than the steering wheel angle at the second time point, controlling the active lateral stabilizer to output reverse torque. At a fourth time point after the third time point, when the steering wheel angle decreases to less than a second preset angle, controlling the active lateral stabilizer to reduce the reverse torque output.

[0021] When the active lateral stabilizer bar outputs reverse torque, the stabilizer bar twisting direction is different, that is, the stabilizer bar twisting direction is different when the actuator outputs torque and when it outputs reverse torque.

[0022] At the third moment, the steering wheel begins to straighten, and the roll angle of the electric vehicle begins to decrease. At the fourth moment, the steering wheel is fully straightened, but roll overshoot can occur, causing discomfort to the occupants. By controlling the active stabilizer bar to output counter-torque starting at the third moment, the change in the electric vehicle's roll angle is mitigated. At the fourth moment, the counter-torque output by the active stabilizer bar reaches its peak, effectively suppressing roll overshoot and improving occupant comfort.

[0023] After the fourth moment, once the steering wheel is straightened, the electric vehicle ends the turn and begins to go straight. At this point, the roll angle of the electric vehicle gradually decreases and approaches zero degrees. The torque output by the active lateral stabilizer bar gradually decreases, causing the roll angle of the electric vehicle to decrease slowly.

[0024] According to the solution in this application, by controlling the magnitude and direction of the output torque of the active lateral stabilizer bar, the overshoot of the roll angle is suppressed, the drastic change of the roll angle is reduced, and the driving experience and safety of the vehicle are improved.

[0025] In conjunction with the first aspect, in some implementations of the first aspect, the control method further includes reducing the torque output of the active lateral stabilizer bar to zero between the second and third time points.

[0026] At the second moment, the steering wheel angle of the electric vehicle stabilizes during the turn, and remains unchanged between the second and third moments. If the active stabilizer bar continues to increase or maintain a large torque output, the roll angle of the electric vehicle will remain unchanged or decrease. Since the electric vehicle is still turning, if the driver cannot feel the change in roll angle during a large turning angle, it will result in a lack of control over the turn, affecting the driving experience. This may cause the driver to continuously increase the turning angle, potentially damaging the electric vehicle's hardware. Therefore, the vehicle controller gradually reduces the torque output of the active stabilizer bar. At this time, the roll angle of the electric vehicle 10 increases slowly, with the roll angle increasing in a preset relationship with lateral acceleration. This avoids excessive suppression of roll angle changes, providing the driver with an appropriate driving feel, preventing excessive suppression from affecting vehicle safety, and improving the comfort of the occupants, thus enhancing the vehicle's overall comfort.

[0027] According to the solution in this application, by controlling the reduction of the torque output of the active lateral stabilizer bar, the driving experience is improved while reducing drastic changes in roll angle, thereby enhancing the driving experience and safety of the vehicle.

[0028] In conjunction with the first aspect, in some implementations of the first aspect, the control method specifically includes, between the first moment and the second moment, controlling the torque output of the active lateral stabilizer bar of the electric vehicle to increase as the height difference between a left wheel and a right wheel increases.

[0029] It should be understood that, in this application, the height difference between a left wheel and a right wheel of an electric vehicle refers to the difference between the distance between the vehicle body and the left wheel and the distance between the vehicle body and the right wheel, or the difference between the distance between the vehicle body at the left wheel and the ground and the distance between the vehicle body at the right wheel and the ground. This difference can be detected by a height sensor of the electric vehicle, which can be installed in the suspension system or on the vehicle body to monitor changes in the height difference between the tires and the vehicle body in real time.

[0030] When the roll angle of an electric vehicle changes, the height difference between the vehicle body and the left and right wheels also changes. Therefore, the roll angle of the electric vehicle at this time can be obtained by the height difference between the left and right wheels indicated by the height sensor. However, because it is difficult for the roll angle sensor of an electric vehicle to directly sample and estimate the roll angle, controlling the active lateral stabilizer bar based on the roll angle sensor signal suffers from inaccurate system control and poor robustness. In contrast, the difference between the heights of the left and right wheels indicated by the height sensor can more accurately and quickly determine the change in the roll angle of the electric vehicle.

[0031] According to the scheme of this application, closed-loop control is adopted using wheel height difference. The torque output of the active lateral stabilizer bar is controlled in conjunction with the torque vector generated by the drive motor to reduce the roll angle of the vehicle body, maximize the lateral force of the tires, provide directional stability, improve the robustness of the system, and enhance the driving experience and safety of the vehicle.

[0032] In conjunction with the first aspect, in some implementations of the first aspect, the control method specifically includes controlling the difference between the driving torque of a left wheel and the driving torque of a right wheel to increase as the steering wheel angle increases between the first moment and the second moment.

[0033] The motor controller or vehicle controller determines the yaw torque required for the electric vehicle to turn based on steering wheel commands and the vehicle's attitude information. This allows them to adjust the difference between the drive torque applied to the left and right wheels. The motor controller or vehicle controller outputs the target yaw rate via steering wheel commands and performs closed-loop control with the vehicle's actual yaw rate to output the vehicle's yaw torque.

[0034] According to the solution in this application, the difference between the driving torque of the left wheel and the driving torque of the right wheel is adjusted according to the steering wheel command, which effectively controls the vehicle's yaw and suppresses the roll angle, thereby improving the vehicle's driving experience and safety.

[0035] In conjunction with the first aspect, in some implementations of the first aspect, the control method further includes, between the second and third time points, keeping the steering wheel angle constant and controlling the difference between the driving torque of a left wheel and the driving torque of a right wheel to be reduced to zero.

[0036] At the second moment, the steering wheel angle of the electric vehicle stabilizes during the turn, and the torque output by the active lateral stabilizer bar reaches its peak. Therefore, by adjusting the yaw torque of the drive motor to reach its peak at the second moment, the overshoot of the roll angle can be effectively suppressed. Between the second and third moments, the steering wheel angle remains unchanged, and the yaw torque required for the electric vehicle to turn gradually decreases. Therefore, the difference between the drive torque of the left wheel and the drive torque of the right wheel is reduced to zero.

[0037] According to the solution in this application, torque vectoring is generated by controlling the drive motor to suppress yaw while ensuring the lateral force of the tires, thereby improving the driving experience and safety of the vehicle.

[0038] In conjunction with the first aspect, in some implementations of the first aspect, the control method specifically includes: at a first moment, the steering angle of the electric vehicle's steering wheel increases from zero to the left, and the driving torque of one left wheel is controlled to be less than the driving torque of one right wheel. At the first moment, the steering angle of the electric vehicle's steering wheel increases from zero to the right, and the driving torque of one left wheel is controlled to be greater than the driving torque of one right wheel.

[0039] When an electric vehicle turns left, the driving torque of the left wheel is controlled to be less than that of the right wheel. When an electric vehicle turns right, the driving torque of the left wheel is controlled to be greater than that of the right wheel, thereby generating a vector torque that suppresses vehicle yaw.

[0040] According to the solution in this application, the torque vector generated by the drive motor is controlled. When turning in different directions, the magnitude of the drive torque on the left and right sides is controlled to be different. While ensuring the lateral force of the tires, the yaw is suppressed, thereby improving the driving experience and safety of the vehicle.

[0041] In conjunction with the first aspect, in some implementations of the first aspect, the control method further includes controlling the driving torque of any wheel to decrease in response to an increase in the slip ratio of any wheel during the turning of the electric vehicle.

[0042] When making sharp turns on wet or slippery surfaces, the wheels are more prone to slippage due to lower friction and load transfer in electric vehicles. This can cause the vehicle to fishtail and wobble, making it difficult for the driver to control and increasing the risk of accidents.

[0043] When an electric vehicle begins to turn, the traction force on the tires fluctuates in real time due to changes in road surface adhesion. As the traction force changes, the tire's slip ratio also changes. Therefore, when the slip ratio of one wheel of an electric vehicle increases, the electric vehicle may slip, requiring control.

[0044] It should be understood that when the adhesion between the wheel and the road surface changes, the speed and torque of the drive motor used to drive the wheel will also change. Therefore, the motor controller can sense and observe the change in road surface adhesion by detecting the change in the speed of the drive motor through the resolver sensor. Thus, the motor controller can actively adjust the actual output torque of the drive motor according to the resolver signal of the drive motor, thereby accurately controlling the slip ratio of the tire.

[0045] According to the scheme of this application, based on the active lateral stabilizer bar control, slip and rotation are observed by the short detection cycle of the resolver sensor near the drive motor, and torque closed-loop adjustment is performed to achieve rapid control of the slip ratio. This solves the problems of slippage and vehicle body swaying in large turns by integrating longitudinal and vertical directions.

[0046] In conjunction with the first aspect, in some implementations of the first aspect, the control method further includes, between the first moment and the second moment, controlling both the driving torque of a left wheel and the driving torque of a right wheel to decrease and controlling the difference between the driving torque of a left wheel and the driving torque of a right wheel to increase.

[0047] Between the first and second moments, the steering wheel angle is large, causing the electric vehicle to turn to one side. Both yaw rate and lateral acceleration increase. Due to the increased roll angle, the lateral force on the tires changes, potentially causing the electric vehicle to slip. Therefore, it's necessary to control the slip ratio while simultaneously controlling the yaw moment to ensure coordinated stability of longitudinal and lateral control. To suppress roll angle and yaw, it's necessary to increase the difference between the drive torque of one left wheel and the drive torque of the right wheel. Simultaneously, to suppress slippage, the drive torque needs to be reduced.

[0048] According to the scheme of this application, based on the lateral stabilizer bar control and the drive motor near-end slip closed-loop control, in coordination with the drive system, the torque vector generated by the electric drive is used for feedforward control. By adjusting the longitudinal force, the lateral force of the tire is guaranteed to the maximum extent, thus providing directional stability.

[0049] In conjunction with the first aspect, in certain implementations of the first aspect, the control method specifically includes controlling the torque output of the active stabilizer bar of the electric vehicle to increase as the height difference between a left wheel and a right wheel increases when the lateral acceleration of the electric vehicle is less than an acceleration threshold. When the lateral acceleration of the electric vehicle is greater than or equal to the acceleration threshold, the active stabilizer bar of the electric vehicle is controlled to adjust its output torque so that the height difference between a left wheel and a right wheel is reduced to a preset value, which increases as the lateral acceleration of the electric vehicle increases.

[0050] When an electric vehicle travels at low speeds or with small steering wheel angles, it experiences minimal lateral acceleration. Therefore, the goal of controlling the roll angle is to minimize it, thereby enhancing passenger safety and improving vehicle comfort. Consequently, when the lateral acceleration is below a threshold, the active stabilizer bar increases its output torque. This torque increases with the difference in height between the left and right wheels, ensuring that the stabilizer bar's torque increases with the vehicle's roll angle. This, in turn, increases the anti-roll moment generated by the stabilizer bar, further reducing the vehicle's roll angle.

[0051] When an electric vehicle travels at high speeds or with large steering wheel angles, it experiences significant lateral acceleration. The target for controlling the roll angle should be a linear relationship between the roll angle and lateral acceleration, avoiding excessive suppression of roll angle changes. This provides the driver with a suitable driving experience, prevents excessive suppression from affecting vehicle safety, and enhances passenger comfort, thus improving overall vehicle comfort. Therefore, when the lateral acceleration is greater than or equal to a threshold acceleration value, the active stabilizer bar adjusts its output torque. The torque output by the active stabilizer bar controls the roll angle of the electric vehicle to increase with increasing lateral acceleration, thereby increasing the anti-roll moment generated by the active stabilizer bar to adjust the rate of change of the roll angle. This preset relationship between the value and the lateral acceleration can be pre-defined.

[0052] According to the scheme of this application, lateral acceleration feedforward is adopted, and closed-loop control is carried out in conjunction with wheel height difference. The output torque of the active lateral stabilizer bar is controlled to reduce the roll angle of the vehicle body. This avoids the inaccuracy of control caused by the difficulty in measuring and estimating the roll angle of the vehicle body, improves the robustness of the system, and enhances the driving experience and safety of the vehicle.

[0053] Secondly, this application provides a vehicle controller for cornering control of an electric vehicle, the electric vehicle including an active stabilizer bar. During the operation of the electric vehicle, when the steering wheel angle increases and the lateral acceleration of the electric vehicle is less than an acceleration threshold, the vehicle controller controls the output torque of the active stabilizer bar to increase with the increase of the height difference between a left and right wheel on the same axle of the electric vehicle. The difference between the drive torque of a left wheel and the drive torque of a right wheel increases with the increase of the steering wheel angle. When the lateral acceleration of the electric vehicle is greater than or equal to the acceleration threshold, the active stabilizer bar adjusts its output torque to make the height difference between a left and right wheel on the same axle of the electric vehicle reach a preset value.

[0054] The vehicle controller can be the vehicle controller or motor controller of an electric vehicle, or a separately configured controller with control capabilities.

[0055] In conjunction with the second aspect, in some implementations of the second aspect, the vehicle controller is also used to control the torque output of the active lateral stabilizer bar to decrease and control the difference between the drive torque of a left wheel and the drive torque of a right wheel to decrease when the steering wheel angle of the electric vehicle increases to be equal to or greater than a preset angle.

[0056] In conjunction with the second aspect, in some implementations of the second aspect, the vehicle controller is also used to control the active lateral stabilizer to output reverse torque when the steering wheel angle of the electric vehicle decreases. When the steering wheel angle of the electric vehicle decreases to less than a second preset angle, the active lateral stabilizer is controlled to reduce the reverse torque output. The difference between the drive torque of one left wheel and the drive torque of one right wheel is controlled to decrease to zero.

[0057] In conjunction with the second aspect, in some implementations of the second aspect, the vehicle controller is also used to control the driving torque of any wheel to decrease in response to an increase in the slip ratio of any wheel during the turning of the electric vehicle.

[0058] Thirdly, this application provides an electric vehicle including a vehicle controller and an active lateral stabilizer bar. The vehicle controller is used to perform the methods described in the first aspect and its various implementations. The active lateral stabilizer bar includes an actuator and a stabilizer bar. The actuator is used to output torque to the stabilizer bar to cause the stabilizer bar to twist.

[0059] Other beneficial effects can be found in the description of the first aspect, and will not be repeated here. Attached Figure Description

[0060] Figure 1 This is a schematic diagram of an electric vehicle turning according to an embodiment of this application;

[0061] Figure 2 This is a schematic diagram of an electric vehicle provided in an embodiment of this application;

[0062] Figure 3 This is a schematic diagram of the architecture of an electric vehicle provided in an embodiment of this application;

[0063] Figure 4 This is a schematic diagram of the vehicle body roll angle control process provided in the embodiments of this application;

[0064] Figure 5 This is a schematic diagram of the vehicle body roll angle control architecture provided in the embodiments of this application;

[0065] Figure 6 This is a schematic diagram of the vehicle body cooperative control process provided in the embodiments of this application;

[0066] Figure 7 This is a schematic diagram of the vehicle body cooperative control results provided in the embodiments of this application. Detailed Implementation

[0067] The technical solutions in this application will now be described in conjunction with the accompanying drawings. The detailed descriptions and drawings of the following embodiments are used to exemplarily illustrate the principles of this application, but should not be used to limit the scope of this application; that is, this application is not limited to the described embodiments.

[0068] The safety of a car's operation largely depends on the control of its roll motion. For example... Figure 1 As shown in (a), in a scenario where a car makes a sharp turn at an intersection on a slippery surface, the vehicle will behave as follows: Figure 1 In (b), significant vehicle body roll occurs, causing the occupants to lean with the vehicle, affecting driving comfort and confidence. During sharp turns, the large axle load transfer leads to tire friction limit loss, particularly lateral force loss, impacting steering performance, increasing driver input frequency, and reducing the maximum lateral acceleration. For example... Figure 1 As shown in (c), lateral force loss can also easily cause wheel slippage, leading to vehicle fishtailing and swaying, making it difficult for the driver to control and easily causing safety accidents.

[0069] In one possible implementation, a passive lateral stabilizer bar is used to control the roll angle of the vehicle body when cornering.

[0070] Understandably, the passive stabilizer bar cannot be actively adjusted, and body roll cannot be further optimized. When encountering road undulations that impact one side of the wheels and body, the torque generated by the passive stabilizer bar will be transmitted to the other side of the wheels and body, causing discomfort to the occupants.

[0071] To address the aforementioned issues, this application provides a control method for reducing cornering roll. The vehicle controller and electric vehicle, through active lateral stabilizer bar control and coordinated yaw rate stabilization control, reduce the body roll angle during cornering, significantly improving vehicle control capabilities, maximizing tire lateral force, providing directional stability, enhancing system robustness, and improving the driving experience and safety of the vehicle.

[0072] Figure 2 and Figure 3 This is a schematic diagram of the architecture of the electric vehicle 10 provided in the embodiments of this application.

[0073] like Figure 2 As shown, the electric vehicle 10 includes a vehicle controller 20, a motor controller 40, a power battery (not shown), and multiple wheels. The motor controller 40 is used to output current to the drive motor to control the output torque of the drive motor to drive the electric vehicle 10.

[0074] The vehicle controller in this application may be the motor controller 40 of the electric vehicle 10, or the vehicle controller 20, or a separately configured controller with control capabilities.

[0075] Understandably, the electric vehicle 10 in this application embodiment can be any type of vehicle such as a sedan, truck, or bus, or it can be a tricycle, two-wheeled vehicle, train, or other transportation device for carrying passengers or goods, or other types of vehicles powered by a power battery. This application embodiment does not limit this. The vehicle includes, but is not limited to, pure electric vehicles (pure EV / battery EV), hybrid electric vehicles (HEV), range-extended electric vehicles (REEV), plug-in hybrid electric vehicles (PHEV), and new energy vehicles (NEV).

[0076] It is understood that the power battery in the embodiments of this application can be a lithium-ion battery, lithium metal battery, lead-acid battery, nickel-cadmium battery, nickel-metal hydride battery, lithium-sulfur battery, lithium-air battery, or sodium-ion battery, etc., and this application does not limit it. In terms of scale, the power battery in the embodiments of this application can be a single cell, a battery module, or a battery pack. The power battery can also power other electrical devices in the vehicle, such as the in-vehicle air conditioner and in-vehicle media player.

[0077] The electric vehicle 10 can be a wheel-side four-motor drive architecture, with the drive motors mounted on the sides of the driving wheels and controlled by individual motor controllers 40. Alternatively, the electric vehicle can have a centralized drive motor architecture, where two drive motors for driving the two front wheels or the two rear wheels are mounted together. There can be one or more motor controllers 40. A one-to-one correspondence can exist between the motor controller 40 and the drive motors, or one motor controller 40 can correspond to multiple drive motors. The motor controller 40 controls the output torque of one or more drive motors to drive the electric vehicle 10.

[0078] In one embodiment, such as Figure 3 As shown in (a), the electric vehicle 10 can be a wheel-side four-drive motor drive architecture, with the drive motors mounted on the sides of the driving wheels and controlled by separate motor controllers. The electric vehicle 10 can also be as follows: Figure 3The centralized four-motor drive architecture shown in (b) has two drive motors for driving the two front wheels or the two rear wheels set together.

[0079] For example, the electric vehicle 10 includes four motor controllers: motor controller 41, motor controller 42, motor controller 43, and motor controller 44. The four motors include drive motor 51, drive motor 52, drive motor 53, and drive motor 54. Motor controller 41 controls drive motor 51 to drive one wheel, motor controller 42 controls drive motor 52 to drive one wheel, motor controller 43 controls drive motor 53 to drive one wheel, and motor controller 44 controls drive motor 54 to drive one wheel.

[0080] In one embodiment, the electric vehicle 10 may also be as follows: Figure 3 As shown in (c), one drive motor drives the two front wheels of the electric vehicle 10, and two drive motors drive the two rear wheels of the electric vehicle 10 respectively.

[0081] In one embodiment, the various architectures mentioned above can also be combined, for example, the front drive adopts a wheel-side drive motor architecture, and the rear drive adopts a centralized drive motor architecture.

[0082] The vehicle controller provided in this application can be any one of multiple motor controllers.

[0083] The electric vehicle 10 also includes an accelerator pedal and a steering wheel. The accelerator pedal is used to indicate the torque output to the wheels of the electric vehicle 10.

[0084] In one embodiment, the motor controller 40 includes a signal interface, through which the motor controller 40 is connected to the vehicle controller 20 and other motor controllers 40. The vehicle controller 20 is signal-connected to the accelerator pedal, and calculates the vehicle torque demand based on the accelerator pedal opening during the operation of the electric vehicle 10, and sends a torque signal to the motor controllers 40 according to the vehicle torque demand. Each motor controller 40 controls the corresponding drive motor to output torque to drive the corresponding wheel according to the torque signal indication.

[0085] In one embodiment, each motor controller 40 may also be directly connected to the accelerator pedal and control the corresponding motor output torque according to the torque signal output by the accelerator pedal.

[0086] The electric vehicle 10 also includes an active lateral stabilizer bar 30.

[0087] The active lateral stabilizer bar 30 can be one or more. For example... Figure 2An active stabilizer bar 30 is installed on each of the front and rear axles. The active stabilizer bar 30 includes an actuator 31 and a stabilizer bar. The actuator 31 outputs torque to the stabilizer bar to cause it to twist. Compared to a passive stabilizer bar, the active stabilizer bar 30 adds an actuator 31, allowing for active control of vehicle attitude adjustment through the output torque of the actuator 31. The actuator 31 can be hydraulic or electric. The stabilizer bar may include one or more components. The active stabilizer bar 30 can generate a real-time adjustable anti-roll torque through active actuation. For example, when an electric vehicle turns left, due to centrifugal force, the vehicle body tilts outward (to the right). The actuator 31 of the active stabilizer bar 30 outputs torque, causing equal and opposite torques on the left and right sides of the stabilizer bar, collectively generating a counter-clockwise anti-roll torque on the vehicle body, thereby reducing body roll. This application does not specifically limit the structural form, power source, or installation method of the active stabilizer bar.

[0088] In one embodiment, the motor controller 40 can connect to the sensors, vehicle controller 20, and active lateral stabilizer bar 30 via a controller area network (CAN) bus, local interconnect network (LIN) bus, high-speed fault-tolerant network protocol (FlexRay), or other types of connection methods, and exchange signals.

[0089] To facilitate understanding of the control method and vehicle controller for reducing cornering roll provided in the embodiments of this application, the following is combined with... Figure 4 The control method and vehicle controller for reducing cornering roll provided in this application are described at the first time t1, the second time t2, the third time t3, and the fourth time t4 during the turning process of an electric vehicle.

[0090] It should be understood that the vehicle controller provided in this application can be a vehicle controller 20, a motor controller 40, or other separately configured controllers with control capabilities.

[0091] like Figure 4 As shown, at the first moment t1, the steering wheel angle of the electric vehicle 10 increases from zero. The vehicle controller controls the increase of the torque output by the active lateral stabilizer bar 30 of the electric vehicle 10 and controls the increase of the difference between the driving torque of the left wheel and the right wheel of the electric vehicle 10 on the same axle.

[0092] At the first moment t1, the driver begins to turn the steering wheel, increasing the steering wheel angle, and the electric vehicle 10 begins to turn, at which point the vehicle body tilts. When the electric vehicle 10 turns at a high speed or a large angle, the centrifugal force caused by the turn results in a roll angle. This roll angle leads to load transfer in the electric vehicle 10, and a large load transfer results in tire friction limit circle loss, especially lateral force loss, affecting steering performance. The vehicle controller increases the output torque by controlling the active lateral stabilizer bar 30, which can effectively reduce the vehicle's roll angle.

[0093] When the active stabilizer bar 30 outputs torque to adjust the roll angle, it changes the vertical load on the tires, thus indirectly affecting the vehicle's yaw stability. Yaw acceleration is the acceleration of the electric vehicle 10's body rotation around its vertical axis during cornering. Yaw acceleration is affected by the electric vehicle 10's speed and cornering angle. As the speed increases, the vehicle needs to generate a greater centrifugal force to overcome the inertial force during cornering, and the yaw acceleration will also increase accordingly. Yaw acceleration is generally proportional to lateral acceleration.

[0094] To ensure lateral tire force and provide directional stability, the vehicle controller can control yaw rate by controlling one or more drive motors to generate a torque vector. When the drive torque of a left wheel on the same axle differs from that of a right wheel, the electric vehicle 10 will generate lateral force due to the unequal left and right drive torques, thus affecting the yaw rate. Therefore, the vehicle controller can adjust the torque output of one or more drive motors to control the difference between the drive torque of a left wheel and the drive torque of a right wheel.

[0095] When the electric vehicle 10 begins to turn, the roll angle begins to increase, and the vehicle yaws. The vehicle controller increases the difference between the output torque and the left and right drive torque by coordinating with the active lateral stabilizer bar 30. This suppresses the roll angle while performing yaw stabilization control, reducing the roll angle at the start of the turn and improving yaw stability.

[0096] In one embodiment, the control method includes: at a first time t1, the steering angle of the electric vehicle 10 to the left increases from zero, and the vehicle controller controls the driving torque of one left wheel to be less than the driving torque of one right wheel. At the first time t1, the steering angle of the electric vehicle 10 to the right increases from zero, and the vehicle controller controls the driving torque of one left wheel to be greater than the driving torque of one right wheel.

[0097] When the electric vehicle 10 turns left, the vehicle controller controls the driving torque of the left wheel of the electric vehicle 10 to be less than the driving torque of the right wheel. When the electric vehicle turns right, the vehicle controller controls the driving torque of the left wheel of the electric vehicle 10 to be greater than the driving torque of the right wheel, thereby generating a vector torque to control the yaw stability of the vehicle.

[0098] In one embodiment, the control method specifically includes: between a first time t1 and a second time t2, the vehicle controller controls the torque output by the active lateral stabilizer bar 30 of the electric vehicle 10 to increase as the height difference between a left wheel and a right wheel increases.

[0099] Between the first moment t1 and the second moment t2, the steering wheel angle increases, the roll angle of the electric vehicle 10 changes, and the height difference between the vehicle body and the left and right side tires also changes. Therefore, the roll angle of the electric vehicle 10 can be obtained by the height difference between the left and right wheels indicated by the height sensor.

[0100] Because it is difficult for the roll angle sensor of electric vehicle 10 to directly sample and estimate the roll angle, controlling the active lateral stabilizer bar 30 based on the roll angle sensor signal suffers from inaccurate control and poor robustness. However, the difference between the height of the left and right wheels indicated by the height sensor can more accurately and quickly determine the change in roll angle of electric vehicle 10.

[0101] According to the scheme of this application, closed-loop control is adopted using wheel height difference. By controlling the output torque of the active lateral stabilizer bar 30 in conjunction with the torque vector generated by the drive motor, the roll angle of the vehicle body is reduced, the lateral force of the tires is maximized, the directional stability is provided, the robustness of the system is improved, and the driving experience and safety of the vehicle are enhanced.

[0102] In one embodiment, the control method specifically includes: between a first time t1 and a second time t2, the vehicle controller controls the difference between the driving torque of a left wheel and the driving torque of a right wheel to increase as the steering wheel angle increases.

[0103] The vehicle controller determines the yaw torque required for the electric vehicle 10 to turn based on steering wheel commands and the vehicle's attitude information. It then adjusts the difference between the drive torque applied to the left and right wheels based on this required yaw torque. The motor controller or vehicle controller outputs the target yaw rate via steering wheel commands and performs closed-loop control with the actual yaw rate to output the vehicle's yaw torque. Between the first time t1 and the second time t2, as the steering wheel angle increases, the yaw torque required for the electric vehicle 10 to turn also increases. Therefore, the difference in drive torque between the left and right wheels controlled by the vehicle controller increases with the increase in steering wheel angle.

[0104] In one embodiment, the control method further includes: in response to an increase in the slip ratio of any wheel during a turn of the electric vehicle 10, the vehicle controller controls a decrease in the drive torque of any wheel.

[0105] If a sharp turn is made on a wet and slippery surface, the wheels are more likely to slip due to the lower friction and the load transfer of the electric vehicle 10. If slippage control is not applied, the electric vehicle 10 will fishtail and wobble, making it difficult for the driver to control and potentially causing a safety accident.

[0106] Starting from moment t1, when electric vehicle 10 begins to turn, the adhesion force on its tires fluctuates in real time due to changes in road surface adhesion. As the road surface adhesion changes, the tire slip ratio also changes. Therefore, when the slip ratio of one wheel of electric vehicle 10 increases, the electric vehicle 10 may slip, requiring slip control. The vehicle controller needs to reduce the drive torque of that wheel to decrease its slip ratio and prevent slippage. Because of the road-tire slippage, the wheel speed increases, and the drive motor speed increases. Therefore, the longitudinal torque of the drive motor is reduced to suppress tire slippage.

[0107] It should be understood that when the adhesion between the wheel and the road surface changes, the speed and torque of the drive motor used to drive the wheel will also change. Therefore, the vehicle controller can sense and observe the change in road surface adhesion by detecting the change in the speed of the drive motor through the resolver sensor. Thus, the vehicle controller can actively adjust the actual output torque of the drive motor according to the resolver signal of the drive motor, thereby accurately controlling the slip ratio of the tire and preventing the electric vehicle from slipping.

[0108] In one embodiment, the control method further includes: between a first time t1 and a second time t2, the vehicle controller controls both the driving torque of a left wheel and the driving torque of a right wheel to decrease and controls the difference between the driving torque of a left wheel and the driving torque of a right wheel to increase.

[0109] See you again Figure 4 The changes in longitudinal torque and yaw torque of the vehicle occur between the first time t1 and the second time t2. During this period, the steering wheel angle is large, and the electric vehicle 10 turns to one side, increasing both yaw rate and lateral acceleration. Due to the increased roll angle, the lateral force on the tires changes, potentially causing the electric vehicle 10 to slip, increasing the wheel slip ratio. Therefore, it is necessary to control the slip ratio while controlling the yaw torque to ensure coordinated stability of longitudinal and lateral control. To suppress roll angle and yaw, it is necessary to increase the difference between the drive torque of one left wheel and the drive torque of the right wheel. Simultaneously, to suppress slippage, it is necessary to reduce the longitudinal drive torque of the electric vehicle 10.

[0110] See also Figure 4 At the second time t2 after the first time t1, the steering wheel angle of the electric vehicle 10 increases from less than the preset angle to equal to or greater than the preset angle, the torque output of the active lateral stabilizer bar 30 decreases, and the difference between the driving torque of one left wheel and the driving torque of one right wheel decreases.

[0111] At the second moment t2, during the turning process of electric vehicle 10, the driver's steering wheel angle stabilizes. At this time, the torque output by the active lateral stabilizer bar 30 reaches its peak, and the difference between the drive torque of the left and right wheels also reaches its peak. During turning, electric vehicle 10 experiences roll angle overshoot, where the roll angle changes beyond its final stable value before returning to and stabilizing near that value. This roll angle overshoot can cause discomfort to passengers and affect vehicle stability and safety. Roll angle overshoot typically occurs when the steering wheel angle increases or decreases to a stable value, such as at the second moment t2. Therefore, by adjusting the torque output by the lateral stabilizer bar 30 and the yaw torque of the left and right drive motors to reach their peak values ​​at the second moment, the vehicle controller can effectively suppress roll angle overshoot and improve passenger comfort.

[0112] In one embodiment, the control method further includes: between a second time t2 and a third time t3, the vehicle controller controls the torque output by the active lateral stabilizer bar 30 to decrease to zero.

[0113] At the second time t2, the steering wheel angle of the electric vehicle 10 stabilizes during the turn. Between the second time t2 and the third time t3, the steering wheel angle remains unchanged. If the vehicle controller continues to increase or maintain a large torque output from the active lateral stabilizer bar 30, the roll angle of the electric vehicle 10 will remain unchanged or decrease. Since the electric vehicle 10 is still turning, if the driver cannot feel the change in roll angle during a large turn, it will result in a lack of control over the turn, affecting the driving experience. This could potentially lead the driver to continuously increase the turn angle, causing damage to the hardware of the electric vehicle 10. Therefore, the vehicle controller gradually decreases the torque output from the active lateral stabilizer bar 30. At this time, the roll angle of the electric vehicle 10 increases slowly, with the roll angle increasing in a preset relationship with lateral acceleration. This avoids excessive suppression of roll angle changes, providing the driver with an appropriate driving experience, preventing excessive suppression of the roll angle from affecting vehicle safety, and improving the comfort of the occupants.

[0114] In one embodiment, the control method specifically includes: when the lateral acceleration of the electric vehicle 10 is less than an acceleration threshold, controlling the torque output of the active lateral stabilizer bar 30 of the electric vehicle 10 to increase as the height difference between a left wheel and a right wheel increases. When the lateral acceleration of the electric vehicle 10 is greater than or equal to the acceleration threshold, controlling the active lateral stabilizer bar 30 of the electric vehicle 10 to adjust the output torque so that the height difference between a left wheel and a right wheel is reduced to a preset value, the preset value increasing as the lateral acceleration of the electric vehicle 10 increases.

[0115] When the electric vehicle 10 is traveling at a low speed or with a small steering wheel angle, the lateral acceleration generated by the electric vehicle 10 is relatively small. The control objective for the roll angle of the electric vehicle 10 should be to minimize the roll angle, thereby ensuring the safety of the occupants and improving vehicle comfort. Therefore, when the lateral acceleration is less than the acceleration threshold, the vehicle controller controls the active lateral stabilizer bar 30 to increase its output torque. The torque output by the active lateral stabilizer bar 30 increases with the increase of the difference in height between the left and right wheels, so that the torque output by the active lateral stabilizer bar 30 increases with the increase of the roll angle of the electric vehicle. This increases the anti-roll moment generated by the active lateral stabilizer bar 30 to reduce the roll angle of the electric vehicle 10.

[0116] When the electric vehicle 10 travels at a high speed or has a large steering wheel angle, it generates a large lateral acceleration. The control objective for the roll angle of the electric vehicle 10 should be a linear increase in the roll angle with lateral acceleration, thus avoiding excessive suppression of roll angle changes, providing the driver with appropriate handling, preventing excessive suppression from affecting vehicle safety, and improving passenger comfort. Therefore, when the lateral acceleration is greater than or equal to the acceleration threshold, the vehicle controller controls the active lateral stabilizer bar 30 to adjust its output torque. The torque output by the active lateral stabilizer bar 30 controls the roll angle of the electric vehicle to increase with increasing lateral acceleration, thereby increasing the anti-roll moment generated by the active lateral stabilizer bar 30 to adjust the rate of change of the roll angle of the electric vehicle 10. This preset value and its correspondence with lateral acceleration can be preset.

[0117] According to the scheme of this application, lateral acceleration feedforward is adopted, and closed-loop control is carried out in conjunction with wheel height difference. The torque of the actuator of the active lateral stabilizer bar is controlled to reduce the roll angle of the vehicle body. This avoids the inaccuracy of control caused by the difficulty in measuring and estimating the roll angle of the vehicle body, improves the robustness of the system, and enhances the driving experience and safety of the vehicle.

[0118] In one embodiment, the control method further includes: between a second time t2 and a third time t3, keeping the steering wheel angle constant, and controlling the difference between the driving torque of a left wheel and the driving torque of a right wheel to be reduced to zero.

[0119] At the second time t2, during the turning process of electric vehicle 10, the steering wheel angle stabilizes, and the steering wheel angle of electric vehicle 10 increases to be equal to or greater than the preset angle. At this time, the torque output by the active lateral stabilizer bar 30 reaches its peak. The vehicle controller adjusts the yaw torque of the left and right drive motors to reach its peak at the second time t2, which can effectively suppress the overshoot of the roll angle. Between the second time t2 and the third time t3, the steering wheel angle remains unchanged, and the yaw torque required for electric vehicle 10 to turn gradually decreases. The difference between the drive torque of one left wheel and the drive torque of one right wheel controlled by the vehicle controller is reduced to zero.

[0120] In one embodiment, the vehicle controller controls the drive torque of a left wheel and the drive torque of a right wheel to increase as the slip rate of one wheel of the electric vehicle 10 decreases.

[0121] Between the second time t2 and the third time t3, the wheels no longer slip, and the wheel slip ratio decreases. At this time, the vehicle controller can increase the longitudinal torque. Throughout the turning process, the vehicle controller performs closed-loop control based on the speed of the drive motor. When the speed of the drive motor decreases, it indicates that the wheel slip ratio of the electric vehicle 10 decreases, the road surface adhesion increases, and the output torque of the drive motor can be increased.

[0122] See also Figure 4 The control method also includes: at the third time t3 after the second time t2, the steering wheel angle is smaller than the steering wheel angle at the second time t2, and the vehicle controller is used to control the active lateral stabilizer bar 30 to output reverse torque.

[0123] When the active lateral stabilizer bar 30 outputs reverse torque, the stabilizer bar torsion direction of the active lateral stabilizer bar 30 is different, that is, the stabilizer bar torsion direction is different when the active lateral stabilizer bar 30 outputs torque and when it outputs reverse torque.

[0124] At the third moment t3, the steering wheel begins to straighten, the steering wheel angle decreases, and the roll angle of the electric vehicle 10 begins to decrease. In order to prevent the roll angle from decreasing too quickly and causing discomfort to the driver and passengers, the vehicle controller controls the active lateral stabilizer bar 30 to output reverse torque to suppress the speed of roll angle reduction.

[0125] At the fourth time t4, following the third time t3, the steering wheel angle decreases to less than the second preset angle, and the vehicle controller controls the active lateral stabilizer bar 30 to reduce the reverse torque output.

[0126] At the fourth moment t4, the steering wheel returns to center, at which point roll overshoot occurs, causing discomfort to the occupants. The vehicle controller controls the active lateral stabilizer bar 30 to output reverse torque starting from the third moment t3, mitigating the change in the electric vehicle's roll angle. The reverse torque output reaches its peak at the fourth moment t4, effectively suppressing roll overshoot and improving occupant comfort.

[0127] In one embodiment, at a fourth time t4, when the steering wheel angle of the electric vehicle 10 decreases to less than a second preset angle, the vehicle controller controls the difference between the driving torque of a left wheel and the driving torque of a right wheel to decrease to zero.

[0128] During the process of straightening the steering wheel, the yaw rate of the electric vehicle 10 decreases, thus reducing the required yaw torque. The vehicle controller actively adjusts the difference between the drive torque for the left wheel and the drive torque for the right wheel to zero.

[0129] According to the scheme of this application, lateral acceleration feedforward is adopted, and closed-loop control is carried out in conjunction with wheel height difference. The torque vector generated by the actuator torque of the active lateral stabilizer bar is controlled by controlling the torque vector of the drive motor, thereby reducing the roll angle of the vehicle body, maximizing the lateral force of the tires, providing directional stability, improving system robustness, and enhancing the driving experience and safety of the vehicle.

[0130] The following is combined with Figure 5 and Figure 6The architecture and process of the roll angle controller for the electric vehicle 10 and vehicle controller provided in the embodiments of this application are described.

[0131] like Figure 5 As shown, the cornering roll angle coordinated control of electric vehicle 10 is mainly divided into three parts: lateral stability control, yaw control and slip control.

[0132] Lateral stability control primarily controls the vehicle's roll angle through the active lateral stabilizer bar 30. Yaw control mainly controls the vehicle's yaw moment through the torque distribution of the drive motor. Slip control primarily identifies the wheel slip rate by detecting the drive motor speed at the near end, thereby controlling the torque accordingly.

[0133] like Figure 5 As shown, the vehicle controller obtains vehicle status information such as lateral acceleration, longitudinal acceleration, yaw rate, tire and vehicle height of the electric vehicle 10 through the vehicle's sensors. Based on the obtained vehicle status information, the lateral stability control forms feedforward through lateral acceleration, considers the suppression of electric vehicle disturbances, adds roll angle closed-loop control, and determines the torque output of the active lateral stabilizer bar.

[0134] Yaw feedforward control outputs the target angular velocity through steering wheel commands and performs closed-loop control with the vehicle's actual yaw angular velocity to output the vehicle's yaw torque. When distributing torque between the left and right drive motors, the results of slip control's observation of tire slippage and lock-up and torque adjustment are used as distribution constraints to ensure that the lateral force of a single wheel is maximized.

[0135] Slip control uses the resolver signal from the resolver sensor and the torque of the drive motor to form a near-end closed loop, which can identify wheel slippage and lock-up, and quickly adjust the torque.

[0136] It should be understood that lateral stability control can be performed by the vehicle controller 20, the motor controller 40, or other separately configured controllers with control capabilities. Yaw control can be performed by the vehicle controller 20 or the motor controller 40. Slip control can be performed by the motor controller 40.

[0137] like Figure 6 As shown, the sensors first collect vehicle attitude information for vehicle control. The required signals may include vehicle speed signals from the vehicle speed sensor, lateral acceleration, longitudinal acceleration, and yaw rate from the inertial measurement unit (IMU), the height difference between the tires and the vehicle body from the height sensor, and resolver signals from the resolver sensor, etc.

[0138] The vehicle controller calculates the torque required by the active stabilizer bar 30, the yaw torque required by the vehicle body, the slip rate of each tire, and the torque distribution of each drive motor based on the vehicle body attitude information.

[0139] The vehicle controller determines whether lateral stability adjustment is needed based on vehicle attitude information, including lateral acceleration and the height difference between the left and right tires; whether yaw adjustment is needed based on the target angular velocity and the current yaw rate; and whether slip control is needed based on the wheel slip rate. It then adjusts the torque output of the active lateral stabilizer bar 30 and the torque output of each drive motor according to the aforementioned control methods.

[0140] Finally, the vehicle controller outputs torque signals to each drive motor, controlling the torque output of each drive motor. The active lateral stabilizer bar 30 outputs a predetermined torque to achieve coordinated control and suppress the roll angle of the electric vehicle 10.

[0141] Control results for example Figure 7 As can be seen from the graph showing the relationship between the height difference between the left and right tires and time, compared with traditional non-cooperative control, the solution proposed in this application significantly reduces the height difference between the left and right tires, thereby reducing body roll and improving the comfort and driving confidence of the driver and passengers.

[0142] It should be understood that Figure 7 The values ​​shown are for illustrative purposes only and do not represent specific values; they may contain some deviations. The trends shown are only used to illustrate the control changes in this application and do not limit the deviations in the actual control process.

[0143] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A control method of an electric vehicle, characterized by, The control method is used for controlling the electric vehicle to reduce roll during cornering of the electric vehicle, and comprises: at a first time instant when a steering wheel angle of the electric vehicle increases from zero, increasing a torque output by an active roll stabilizer of the electric vehicle and increasing a difference between a driving torque of a left wheel and a driving torque of a right wheel of the electric vehicle; at a second time instant after the first time instant when the steering wheel angle increases from less than a preset angle to equal to or greater than the preset angle, decreasing the torque output by the active roll stabilizer and decreasing the difference between the driving torque of the left wheel and the driving torque of the right wheel.

2. The control method according to claim 1, characterized by, The control method further comprises: at a third time instant after the second time instant when the steering wheel angle is less than the steering wheel angle at the second time instant, controlling the active roll stabilizer to output a reverse torque; at a fourth time instant after the third time instant when the steering wheel angle decreases to less than a second preset angle, controlling the active roll stabilizer to decrease the reverse torque output.

3. The control method according to claim 2, characterized by, The control method further comprises: between the second time instant and the third time instant, controlling the torque output by the active roll stabilizer to decrease to zero.

4. The control method according to claim 1, characterized by, The control method specifically comprises: between the first time instant and the second time instant, controlling the torque output by the active roll stabilizer of the electric vehicle to increase with an increase in a height difference between the left wheel and the right wheel.

5. The control method according to claim 1, characterized by, The control method specifically comprises: between the first time instant and the second time instant, controlling the difference between the driving torque of the left wheel and the driving torque of the right wheel to increase with an increase in the steering wheel angle.

6. The control method according to claim 2, characterized by The control method further comprises: between the second time instant and the third time instant, the steering wheel angle remaining unchanged, and controlling the difference between the driving torque of the left wheel and the driving torque of the right wheel to decrease to zero.

7. The control method according to claim 1, characterized by, The control method specifically comprises: at a first time instant when a steering wheel angle of the electric vehicle to the left increases from zero, controlling the driving torque of the left wheel to be less than the driving torque of the right wheel; at a first time instant when a steering wheel angle of the electric vehicle to the right increases from zero, controlling the driving torque of the left wheel to be greater than the driving torque of the right wheel.

8. The control method according to claim 1 or 2, characterized by, The control method further comprises: in response to an increase in a slip ratio of any one wheel of the electric vehicle during cornering of the electric vehicle, controlling the driving torque of the any one wheel to decrease.

9. The control method according to claim 8, characterized by, The control method further comprises: between the first time instant and the second time instant, controlling the driving torque of the left wheel and the driving torque of the right wheel to both decrease and controlling the difference between the driving torque of the left wheel and the driving torque of the right wheel to increase.

10. The control method according to claim 4, characterized by The control method specifically comprises: when a lateral acceleration of the electric vehicle is less than an acceleration threshold, controlling a torque output by an active roll stabilizer of the electric vehicle to increase with an increase in a height difference between the left wheel and the right wheel; When the lateral acceleration of the electric vehicle is greater than or equal to the acceleration threshold, the active roll stabilizer of the electric vehicle is controlled to adjust the output torque so that the height difference between the one left wheel and the one right wheel of the electric vehicle reaches a preset value, the preset value increasing with the increase of the lateral acceleration of the electric vehicle.

11. A vehicle controller for reducing cornering roll of an electric vehicle, characterized by, The electric vehicle comprises an active roll stabilizer; the vehicle controller is configured to: When the steering wheel angle of the electric vehicle increases during the driving of the electric vehicle, When the lateral acceleration of the electric vehicle is less than the acceleration threshold, the torque output by the active roll stabilizer is controlled to increase with the increase of the height difference between the one left wheel and the one right wheel of the electric vehicle; the difference between the driving torque of the one left wheel and the driving torque of the one right wheel is controlled to increase with the increase of the steering wheel angle; When the lateral acceleration of the electric vehicle is greater than or equal to the acceleration threshold, the active roll stabilizer of the electric vehicle is controlled to adjust the output torque so that the height difference between the one left wheel and the one right wheel of the electric vehicle reaches a preset value, the preset value increasing with the increase of the lateral acceleration of the electric vehicle.

12. The vehicle controller of claim 11, wherein, The vehicle controller is further configured to: When the steering wheel angle of the electric vehicle increases to be equal to or greater than a preset angle, the torque output by the active roll stabilizer is controlled to decrease and the difference between the driving torque of the one left wheel and the driving torque of the one right wheel is controlled to decrease.

13. The vehicle controller of claim 11, wherein, The vehicle controller is further configured to: When the steering wheel angle of the electric vehicle decreases, the active roll stabilizer is controlled to output a reverse torque; When the steering wheel angle of the electric vehicle decreases to be less than a second preset angle, the active roll stabilizer is controlled to decrease the reverse torque output; the difference between the driving torque of the one left wheel and the driving torque of the one right wheel is controlled to decrease to zero.

14. The vehicle controller of claim 11, wherein, The vehicle controller is further configured to: In response to the slip ratio of any one wheel of the electric vehicle increasing during the turning of the electric vehicle, the driving torque of the any one wheel is controlled to decrease.

15. An electric vehicle characterized by comprising: The electric vehicle comprises a vehicle controller and an active roll stabilizer, the vehicle controller is configured to perform the method of any one of claims 1-10, and the active roll stabilizer comprises an actuator and a stabilizer, the actuator is configured to output torque to the stabilizer to twist the stabilizer.

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