Electric vehicle control method, vehicle controller, and electric vehicle

Abstract

Disclosed are an electric vehicle control method, a vehicle controller, and an electric vehicle. The control method is used for controlling an electric vehicle when a blowout occurs at one wheel while the electric vehicle is traveling at a speed greater than a preset vehicle speed. The control method comprises: at a first moment after a blowout occurs at one wheel of an electric vehicle, controlling to reduce the driving torque of the wheel and controlling to reduce the braking force outputted to the wheel by a braking system of the electric vehicle. The control method can quickly adjust the torque and braking force, quickly reset the driving torque and braking force, fully utilize a lateral force friction limit, provide sufficient margin for steering lateral force, and facilitate directional stability control, thereby improving vehicle safety.

Description

Electric vehicle control methods, vehicle controllers and electric vehicles

[0001] This application claims priority to Chinese Patent Application No. 202411926151.X, filed on December 23, 2024, entitled "Electric Vehicle Control Method, Vehicle Controller and Electric Vehicle", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of new energy vehicles, and more specifically, to an electric vehicle control method, a vehicle controller, and an electric vehicle. Background Technology

[0003] With the development of the vehicle industry and the increasing number of vehicles year by year, traffic safety accidents are receiving more and more attention. Tires, as the only key component on a vehicle that directly contacts the ground, have a significant impact on the vehicle's power, braking, ride comfort, and handling stability during operation. A tire blowout in an electric vehicle at high speed can have a significant impact on vehicle stability and safety. A tire blowout can cause a significant deviation in the vehicle's direction and trajectory within a very short time, making it easy for the driver to make incorrect adjustments in a panic, thus increasing the difficulty of vehicle control. At high speeds, and when the driver is not applying steering wheel control, the vehicle's direction and trajectory can deviate unexpectedly, significantly impacting vehicle stability and safety.

[0004] The current mainstream approach is to diagnose tire pressure values ​​to identify rapid pressure loss, slow pressure loss, and tire blowout. Based on this, the electronic stability program (ESC) uses the non-blowout axle to generate yaw moment to control vehicle stability and prevent loss of control from causing safety accidents. However, this method has a long stability control time, low control bandwidth, and cannot quickly control the vehicle.

[0005] Therefore, how to achieve stable control when an electric vehicle experiences a tire blowout is a problem that needs to be solved. Summary of the Invention

[0006] This application provides an electric vehicle control method, a vehicle controller, and an electric vehicle. After detecting a tire blowout in the electric vehicle, the torque is quickly adjusted to rapidly reset the drive torque and braking force of the blown wheel to zero, providing sufficient margin for steering lateral force, making it easier to achieve stable control, and improving the safety and stability of the vehicle.

[0007] In a first aspect, this application provides a control method for an electric vehicle, which is used to control the electric vehicle when a tire blows out while the vehicle is traveling at a speed greater than a preset speed. The control method includes, at the first moment after a tire blowout, controlling the driving torque of the affected wheel to decrease and controlling the braking force output by the vehicle's braking system to decrease the braking force to that wheel.

[0008] The electric vehicle can be an electric vehicle or a hybrid vehicle. It can have a distributed drive motor or a centralized drive motor architecture, possessing multiple drive motors and multiple motor controllers. The drive motors can be wheel-side motors or wheel hub motors, and each drive motor can independently drive one wheel of the vehicle.

[0009] When an electric vehicle experiences a tire blowout while in motion, the blown wheel will produce a blowout braking effect. The sudden increase in drag on the blown wheel reduces its radius, causing unequal forces on the left and right wheels of the drive axle and generating yaw torque. This will cause the vehicle to veer off course, and the electric vehicle will yaw towards the side of the blown wheel. To control yaw caused by a tire blowout in an electric vehicle, it is necessary to ensure that the wheels receive sufficient lateral force. Reducing the torque on the blown wheel can provide sufficient margin for lateral steering force in the electric vehicle.

[0010] The tire blowout detection and control are only initiated when the electric vehicle's speed exceeds a preset speed, preventing misjudgments and erroneous control during vehicle acceleration or low-speed driving. The preset speed can be pre-calibrated based on real-vehicle experiments and / or model calculations, or it can be pre-set considering overall vehicle requirements and performance.

[0011] According to the solution in this application, when an electric vehicle experiences a tire blowout, the torque and braking force are quickly adjusted to rapidly reduce the driving torque and braking force, making full use of the lateral force friction limit, providing sufficient margin for steering lateral force, facilitating directional stability control, and improving vehicle safety.

[0012] In conjunction with the first aspect, in some implementations of the first aspect, the control method specifically includes: after the first moment, controlling the driving torque of one wheel to be reduced to zero and controlling the braking force output by the braking system of the electric vehicle to one wheel to be reduced to zero.

[0013] To control the yaw caused by a tire blowout in an electric vehicle, it is necessary to ensure that the wheel is subjected to sufficient lateral force. By zeroing the torque of the blown tire, a sufficiently large margin can be provided for the steering lateral force of the electric vehicle.

[0014] According to the solution in this application, when an electric vehicle experiences a tire blowout, the torque and braking force are quickly adjusted to zero, making full use of the lateral force friction limit, providing sufficient margin for steering lateral force, facilitating directional stability control, and improving vehicle safety.

[0015] In conjunction with the first aspect, in some implementations of the first aspect, the control method specifically includes: at a second moment after the first moment, the opening of the accelerator pedal of the electric vehicle is greater than a preset accelerator opening, and the driving torque of the wheel on the same side of one wheel is controlled to be greater than the driving torque of the wheel diagonally opposite to one wheel.

[0016] In the first instant, the electric vehicle detects a tire blowout. After resetting the drive torque and braking force of the blown tire to zero, it can generate an asymmetrical yaw moment through the non-blowout axle to suppress the yaw caused by the tire blowout and correct the deviation of the electric vehicle.

[0017] At the second moment, the accelerator pedal of the electric vehicle is opened to a greater degree than the preset accelerator pedal opening. At this time, the driver presses the accelerator pedal, and the drive system of the electric vehicle outputs drive torque to generate unequal drive torque on the left and right wheels of the non-burst axle, thereby achieving yaw suppression.

[0018] It should be understood that the second moment and the first moment can be very close, that is, while controlling the reduction of the driving torque of one wheel and controlling the reduction of the braking force output by the braking system of the electric vehicle to one wheel, the driving torque of the wheel on the same side of one wheel and the driving torque of the wheel diagonally opposite one wheel can be adjusted.

[0019] The two front wheels and the two rear wheels of an electric vehicle are coaxial. The left front wheel and the right rear wheel are diagonally opposite, as are the right front wheel and the left rear wheel. The left front wheel and the left rear wheel are on the same side, as are the right front wheel and the right rear wheel. A wheel on the same side and a wheel diagonally opposite are two wheels on the same axle, neither of which has experienced a tire blowout, and both are located on different axles from the wheel that experienced the blowout.

[0020] The accelerator pedal in this application can also be called the power pedal or throttle pedal. The opening degree of the accelerator pedal indicates the amount of driving force required by the driver. The larger the opening degree of the accelerator pedal, the greater the driver's demand for driving force, and the greater the torque required from the drive motor. The motor controller can control the output torque of the drive motor according to the opening degree of the accelerator pedal. The larger the opening degree of the accelerator pedal, the greater the torque output by the drive motor; the smaller the opening degree of the accelerator pedal, the smaller the torque output by the drive motor. The torque output by the drive motor controlled by the motor controller changes with the change in the opening degree of the accelerator pedal.

[0021] For electric vehicles with multiple drive motors that drive two wheels on the same axle, different magnitudes of drive torque can be generated by controlling one or both drive motors on the left and right sides to work simultaneously. This allows for torque vector control of the two drive motors to generate yaw correction torque, thus suppressing the yaw of the entire vehicle.

[0022] In this application, the driving torque of a wheel can be understood as the torque output by the drive motor used to drive that wheel. Controlling the driving torque of a wheel on the same side as another wheel to be greater than the driving torque of the wheel diagonally opposite the other wheel can be achieved by controlling the driving torque of one wheel to increase while the driving torque of the other wheel remains unchanged or decreases; or by controlling the increase in the driving torque of one wheel to be greater than the increase in the driving torque of the other wheel; or by controlling the decrease in the driving torque of one wheel to decrease while the driving torque of the other wheel remains unchanged; or by controlling the decrease in the driving torque of one wheel to be less than the decrease in the driving torque of the other wheel. It should be understood that when a tire blows out, to ensure the safety of the occupants and the vehicle, the vehicle speed is usually reduced and controlled. Therefore, it is common practice to control the driving torque of one wheel to decrease while the driving torque of the other wheel remains unchanged; or to control the decrease in the driving torque of one wheel to be less than the decrease in the driving torque of the other wheel. This allows the vehicle to reduce speed while reducing yaw.

[0023] It should be understood that drive torque can also be negative. A drive motor consists of stator windings and a rotor. By outputting alternating current to the three-phase stator windings, the output torque of the drive motor can be controlled. By adjusting the magnitude of the stator winding current and the phase of the three-phase current through the motor controller, the strength and direction of the stator magnetic field can be changed, thereby altering the interaction force between the stator and rotor, i.e., the motor torque. Changing the phase of the three-phase current output to the motor causes the rotor to cut the magnetic field generated by the stator windings, converting the rotor's kinetic energy into electrical energy that is input into the power battery; in this case, the motor outputs negative torque. Changing the magnitude of the three-phase current output to the motor through the motor controller can increase or decrease the positive or negative torque output of the motor.

[0024] When the driving torque of a wheel is negative, the drive motor driving that wheel outputs a reverse torque to brake that wheel.

[0025] According to the solution of this application, by adjusting the torque output of two drive motors on the non-explosion tire axle, torque vector control is performed to generate yaw moment, reduce the yaw of the whole vehicle, quickly achieve vehicle stability control, effectively control the driving posture of the electric vehicle when a tire blowout occurs, and improve vehicle safety.

[0026] In conjunction with the first aspect, in certain implementations of the first aspect, the control method specifically includes: if the left front tire of the electric vehicle blows out, at a second moment, controlling the driving torque of the left rear tire of the electric vehicle to be greater than the driving torque of the right rear tire; if the right front tire of the electric vehicle blows out, at the second moment, controlling the driving torque of the left rear tire of the electric vehicle to be less than the driving torque of the right rear tire.

[0027] When the left front tire of an electric vehicle blows out, if the driver does not apply steering wheel control, the electric vehicle will generate a yaw moment to the left (counterclockwise relative to the vehicle). At this time, the driving torque of the left rear wheel is greater than that of the right rear wheel, so that the electric vehicle generates a yaw correction moment to the right (clockwise relative to the vehicle), thereby reducing the yaw of the electric vehicle.

[0028] When the right front tire of an electric vehicle blows out, if the driver does not apply steering wheel control, the electric vehicle will generate a yaw moment to the right (clockwise relative to the vehicle). At this time, the driving torque of the right rear wheel is greater than that of the left rear wheel, so that the electric vehicle generates a yaw correction moment to the left (counterclockwise relative to the vehicle), thereby reducing the yaw of the electric vehicle.

[0029] According to the solution in this application, when the left front tire of an electric vehicle blows out, the driving torque of the left rear tire is controlled to be greater than that of the right rear tire, and when the right front tire of an electric vehicle blows out, the driving torque of the right rear tire is controlled to be greater than that of the left rear tire. The difference in driving torque can reduce vehicle yaw, quickly achieve vehicle stability control, and improve vehicle safety.

[0030] In conjunction with the first aspect, in some implementations of the first aspect, the control method specifically includes: at a second moment, controlling the difference between the driving torque of the wheel on the same side of a wheel and the driving torque of the wheel diagonally opposite a wheel to increase as the speed of the electric vehicle increases.

[0031] When an electric vehicle experiences a tire blowout while driving, the higher the vehicle's speed, the greater the yaw rate deviation caused by the blowout, the greater the yaw correction torque required for blowout stability control, and the greater the torque differential output from the left and right drive motors of the non-blowout axle.

[0032] According to the solution in this application, the torque difference between the two drive motors on the rear axle is determined based on the change in yaw rate when a tire blows out. By making full use of torque vector control, vehicle stability control can be quickly achieved, thereby improving vehicle safety.

[0033] In conjunction with the first aspect, in some implementations of the first aspect, the control method further includes: at a third moment after the first moment, the opening degree of the brake pedal of the electric vehicle is greater than the preset brake opening degree, and the braking force output by the braking system to the wheel on the same side of a wheel is less than the braking force output to the wheel diagonally opposite to a wheel.

[0034] At the third moment, the opening of the electric vehicle's brake pedal is greater than the preset braking opening. At this time, the driver presses the brake pedal, controlling the electric vehicle's braking system to output unequal braking forces to the left and right wheels of the non-exploded axle, generating a yaw moment, thereby suppressing the yaw caused by the tire blowout.

[0035] It should be understood that there is usually a period of time between a tire blowout in an electric vehicle and the driver's awareness of it. During this time, the driver maintains their previous driving posture and continues to press the accelerator pedal. When the driver notices the blowout and intervenes, they may continue to press the accelerator pedal to try to maintain speed, or they may press the brake pedal to try to stop the vehicle. Therefore, the second moment usually occurs during the entire blowout stabilization and control process, while the third moment may not occur during the blowout process, and the third moment usually occurs after the second moment.

[0036] The brake pedal in this application can also be referred to as a brake or brake pedal. The opening degree of the brake pedal indicates the amount of braking force required by the driver. The larger the opening degree of the brake pedal, the greater the driver's demand for braking, and the greater the torque required from the braking system. During normal vehicle operation, the braking system outputs the torque indicated by the brake pedal opening degree. The larger the brake pedal opening degree, the greater the braking force output by the braking system; the smaller the brake pedal opening degree, the smaller the braking force output by the braking system. The braking force output by the braking system varies with the opening degree of the brake pedal.

[0037] The braking system may include multiple wheel-end braking devices, with each wheel having at least one wheel-end braking device. The wheel-end braking devices are used to output braking force to the corresponding wheels to brake the electric vehicle. Thus, by controlling one or both wheel-end braking devices on the left and right sides to operate simultaneously, different magnitudes of braking force can be generated, thereby producing a yaw correction torque through asymmetrical braking force and suppressing overall vehicle yaw.

[0038] According to the solution in this application, the braking force output by the braking system to the two wheels of the non-blowout axle is unequal, thereby generating a yaw moment, reducing the yaw of the entire vehicle, quickly achieving vehicle stability control, effectively controlling the driving posture of the electric vehicle when a tire blowout occurs, and improving vehicle safety.

[0039] In conjunction with the first aspect, in certain implementations of the first aspect, the control method specifically includes: if the left front tire of the electric vehicle blows out, at a third moment, controlling the braking force output by the braking system to the left rear tire of the electric vehicle to be less than the braking force output to the right rear tire; if the right front tire of the electric vehicle blows out, at a third moment, controlling the braking force output by the braking system to the left rear tire of the electric vehicle to be greater than the braking force output to the right rear tire.

[0040] When the left front tire of an electric vehicle blows out, if the driver does not apply steering wheel control, the electric vehicle will generate a yaw moment to the left (counterclockwise relative to the vehicle). At this time, the braking force output by the braking system to the left rear wheel is less than the braking force output to the right rear wheel, causing the electric vehicle to generate a yaw correction moment to the right (clockwise relative to the vehicle), thereby reducing the yaw of the electric vehicle.

[0041] When the right front tire of an electric vehicle blows out, if the driver does not apply steering wheel control, the electric vehicle will generate a yaw moment to the right (clockwise relative to the vehicle). At this time, the braking force output by the braking system to the left rear wheel is greater than the braking force output to the right rear wheel, causing the electric vehicle to generate a yaw correction moment to the left (counterclockwise relative to the vehicle), thereby reducing the yaw of the electric vehicle.

[0042] According to the solution in this application, when the left front tire of an electric vehicle blows out, the braking force on the left rear tire is controlled to be less than the driving torque of the right rear tire; when the right front tire of an electric vehicle blows out, the braking force on the left rear tire is controlled to be greater than the driving torque of the right rear tire. The difference in braking force can reduce vehicle yaw, quickly achieve vehicle stability control, and improve vehicle safety.

[0043] In conjunction with the first aspect, in some implementations of the first aspect, the control method specifically includes: at a third moment, the difference between the braking force output by the control braking system to the wheel on the same side of a wheel and the braking force output to the wheel diagonally opposite a wheel increases as the speed of the electric vehicle increases.

[0044] When an electric vehicle experiences a tire blowout while driving, the higher the vehicle's speed, the greater the yaw rate deviation caused by the blowout, the greater the yaw correction torque required for blowout stability control, and the greater the difference in braking force between the left and right wheels of the non-blowout axle.

[0045] According to the solution in this application, the difference in braking force on the two wheels of the rear axle is determined based on the change in yaw rate when a tire blows out, making full use of the braking system control to quickly achieve vehicle stability control and improve vehicle safety.

[0046] In conjunction with the first aspect, in some implementations of the first aspect, the control method further includes: after the first moment, controlling the suspension system of the electric vehicle to adjust the damping of the shock absorber of one wheel to increase.

[0047] The suspension system connects the electric vehicle body to the wheels, providing support, cushioning, and stability during vehicle operation. The suspension system may include shock absorbers. Each wheel can be individually connected to the electric vehicle body via a shock absorber. For suspension systems with adjustable damping shock absorbers, when a tire blowout occurs, a target damping coefficient or target damping level can be sent to the suspension system to adjust the damping of each shock absorber. For the shock absorber of the blown-out wheel, the damping can be increased to ensure wheel contact with the road surface. For other wheels, the damping of the shock absorbers may or may not be changed.

[0048] According to the solution in this application, the performance of the shock absorber can be changed by adjusting the damping force of the shock absorber. When a tire blows out, the damping of the shock absorber on the blown tire is increased to ensure contact between the blown tire and the ground, thereby improving the stability of the vehicle body and the ride comfort.

[0049] In conjunction with the first aspect, in some implementations of the first aspect, the control method further includes: after the first moment, controlling the suspension system of the electric vehicle to adjust the damping of the shock absorber of one wheel to increase to a target damping, the target damping increasing with the increase of the speed of the electric vehicle.

[0050] When an electric vehicle experiences a tire blowout while driving, the higher the vehicle's speed, the greater the force required to stabilize the vehicle. Therefore, adjusting the wheels to the target position with greater damping can provide sufficient support.

[0051] According to the solution in this application, the damping of the shock absorber of the blown tire is determined based on the change in yaw rate during a tire blowout, making full use of the stability control function of the suspension system to quickly achieve vehicle stability control and improve vehicle safety.

[0052] In conjunction with the first aspect, in some implementations of the first aspect, the control method further includes: after the first moment, controlling the suspension system of the electric vehicle to adjust the body height of one wheel to be greater than the body height of the other wheels of the electric vehicle.

[0053] The suspension system can include air suspension or fully active suspension. When an electric vehicle experiences a tire blowout, the suspension system can send a target wheel suspension height signal, allowing adjustment of the suspension height at that wheel. In one implementation, the air suspension can control the lowering of the suspension height at the non-blowout wheel while maintaining a constant suspension height at the blowout wheel, thus ensuring the vehicle's height at the blowout wheel is greater than that of the other wheels. In another implementation, the fully active suspension can control the raising or lowering of the suspension height at each wheel. For the blowout wheel, the fully active suspension can control the raising of the vehicle's height at the blowout wheel, ensuring the blowout wheel's height is greater than that of the other wheels, thereby raising the blowout wheel. For the suspension height of the non-blowout wheels, the fully active suspension can adjust the height according to the balance of the electric vehicle's body posture.

[0054] According to the solution in this application, when an electric vehicle experiences a tire blowout, adjusting the suspension height between the blown-out wheel and other wheels can effectively prevent the vehicle from overturning, reduce yaw caused by the blowout, and improve the vehicle's stability and safety.

[0055] In conjunction with the first aspect, in some implementations of the first aspect, the control method further includes: at a second moment after the first moment, the opening of the accelerator pedal of the electric vehicle is greater than the preset accelerator opening, and the steering system of the electric vehicle is controlled to adjust the steering angle of the two rear wheels.

[0056] The steering system of an electric vehicle can control the steering of the rear wheels. The steering system can change the rotation angle and direction of the two rear wheels, allowing the electric vehicle to effectively adjust its steering and handling characteristics through different steering methods. At low speeds, when the rear wheels steer in the opposite direction to the front wheels, the turning radius can be reduced, improving the overall handling and agility of the vehicle. At higher speeds, when the rear wheels steer in the same direction as the front wheels, the yaw moment generated by steering operations can be effectively reduced, enhancing vehicle stability.

[0057] When an electric vehicle experiences a tire blowout while in motion, the blown wheel will exhibit a blowout braking effect, causing a sudden increase in wheel speed and a veer in the vehicle's direction of travel. The vehicle will yaw towards the side of the blown-out wheel. To ensure the safety of the driver and the vehicle, the rear-wheel steering system can adjust the steering of the two rear wheels to generate a yaw control torque. This yaw control torque can then counteract the yaw caused by the tire blowout, reducing the magnitude of the yaw.

[0058] According to the solution in this application, the yaw caused by tire blowout in electric vehicles is suppressed by adjusting the rear wheel steering angle, thereby quickly achieving vehicle stability control, effectively controlling the driving posture of electric vehicles when a tire blowout occurs, and improving vehicle safety.

[0059] In conjunction with the first aspect, in some implementations of the first aspect, the control method specifically includes: if the left front tire of the electric vehicle blows out, at a second moment, controlling the steering system of the electric vehicle to adjust the two rear wheels to turn to the left; if the right front tire of the electric vehicle blows out, at a second moment, controlling the steering system of the electric vehicle to adjust the two rear wheels to turn to the right.

[0060] When the left front tire of an electric vehicle blows out, if the driver does not apply steering wheel control, the electric vehicle will generate a yaw moment to the left (counterclockwise relative to the vehicle). If the rear wheel steering system is turned to the left, this leftward steering will generate a yaw control moment to the right (clockwise relative to the vehicle). The yaw moment and the yaw control moment cancel each other out, reducing the yaw rate of the electric vehicle. Conversely, when the right front tire of an electric vehicle blows out, if the driver does not apply steering wheel control, the electric vehicle will generate a yaw moment to the right (clockwise relative to the vehicle). If the rear wheel steering system is turned to the right, this rightward steering will generate a yaw control moment to the left (counterclockwise relative to the vehicle). The yaw moment and the yaw control moment cancel each other out, reducing the yaw rate of the electric vehicle.

[0061] According to the solution in this application, rear-wheel steering can effectively reduce vehicle yaw during a tire blowout, quickly achieve vehicle stability control, and improve vehicle safety.

[0062] In conjunction with the first aspect, in some implementations of the first aspect, the control method specifically includes: at a second moment, controlling the steering system of the electric vehicle to adjust the steering angle of the two rear wheels to decrease as the speed of the electric vehicle increases.

[0063] The faster the vehicle speed, the higher the risk of a tire blowout, and the greater the impact on the vehicle's attitude and trajectory. At this time, the yaw control torque applied by steering will also be greater, and the danger will also be greater. The higher the speed, the easier it is to lose control. Therefore, the higher the speed, the smaller the steering angle of the rear wheel steering system.

[0064] According to the solution in this application, when a tire blows out at different vehicle speeds, the vehicle controller adjusts the steering angle of the rear wheels according to the different vehicle driving conditions, reducing the risk of loss of vehicle control and effectively improving vehicle safety.

[0065] In conjunction with the first aspect, in some implementations of the first aspect, the control method further includes: at a second moment after the first moment, when the opening of the accelerator pedal of the electric vehicle is greater than a preset accelerator opening and the change in steering wheel angle is greater than a steering threshold, controlling the steering system of the electric vehicle to adjust the steering angle of the two front wheels to be less than the steering angle indicated by the steering wheel angle.

[0066] When a tire blows out in an electric vehicle, if the driver is pressing the accelerator pedal and the vehicle is still moving, the driver may make a sharp steering correction upon sensing the blowout. This action could exacerbate the safety risk of the blowout. Therefore, when the steering wheel angle exceeds a certain threshold, appropriate suppression strategies are needed to control the steering system to suppress changes in the front wheel steering angle and limit the steering wheel rotation rate to prevent risks caused by sudden steering wheel movements.

[0067] According to the solution proposed in this application, when an electric vehicle experiences a tire blowout, it inhibits the driver from making large steering wheel movements, thereby reducing the risk of the electric vehicle losing control and improving the vehicle's stability and safety.

[0068] In conjunction with the first aspect, in some implementations of the first aspect, the control method further includes: at a second moment, when the opening of the accelerator pedal of the electric vehicle is greater than a preset accelerator opening and the change in steering wheel angle is greater than a direction threshold, controlling the steering system to adjust the two rear wheels to turn in the opposite direction to the steering angle indicated by the steering wheel angle.

[0069] When a tire blows out in an electric vehicle, the driver may make a sharp steering correction as soon as they perceive the blowout. This operation may exacerbate the safety risk of the blowout. Therefore, when the steering wheel angle exceeds the steering threshold, the steering system will be controlled to suppress the change in the front wheel steering angle and use the rear wheel steering to assist the driver in achieving the steering purpose. The direction of the rear wheel steering is opposite to the direction of the front wheel steering, and the direction of the rear wheel steering is opposite to the direction of the steering wheel steering.

[0070] According to the solution in this application, when an electric vehicle experiences a tire blowout, the driver is prevented from making large steering wheel movements, while the rear wheel steering assists in steering the electric vehicle, thereby improving the operability of the electric vehicle, reducing the risk of loss of control, and enhancing the stability and safety of the vehicle.

[0071] 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 first time point, the opening degree of the brake pedal of the electric vehicle is greater than a preset brake opening degree, and the difference between the driving torque of the wheel on the same side of one wheel and the driving torque of the wheel diagonally opposite to one wheel is reduced to zero. At a fourth time point after the first time point, in response to the electric vehicle speed being less than a safety threshold, the difference between the braking force output by the braking system to the wheel on the same side of one wheel and the braking force output to the wheel diagonally opposite to one wheel is reduced to zero.

[0072] At the third moment, the driver depresses the brake pedal, at which point the difference in control drive torque decreases to zero. At the fourth moment, the electric vehicle's speed decreases to a safe range or has come to a stop, at which point the difference in control drive torque decreases to zero, and the difference in braking force between the left and right wheels also decreases to zero.

[0073] According to the solution in this application, when the electric vehicle decelerates to a safe range, the output of yaw torque stops, thus ensuring the safety of the vehicle.

[0074] In conjunction with the first aspect, in certain implementations of the first aspect, a tire blowout of one wheel of an electric vehicle includes a load torque of one wheel exceeding a preset value, and / or a tire pressure of one wheel falling below a pressure threshold, and / or a wheel speed increase of one wheel exceeding the wheel speed increase of other wheels within a preset time period.

[0075] Electric vehicles can obtain signals representing the vehicle's driving status, such as vehicle speed, steering wheel angle, yaw rate, and tire pressure, from vehicle sensors such as vehicle speed sensors, steering wheel angle sensors, inertial sensors, and tire pressure sensors, and complete tire blowout detection and tire blowout wheel positioning based on these signals.

[0076] The load torque of a tire that has blown out increases dramatically, exhibiting a large, step-like fluctuation within a short period, followed by a significant increase in torque value after stabilization. The resistance experienced by the blown-out wheel also increases rapidly; for example, rolling resistance can be 20-30 times greater than that of a normal tire. This characteristic can be used to detect tire blowouts. Load torque can be observed using a load monitoring device. By measuring the drive motor speed through a resolver signal, the load torque can be calculated, thus enabling the monitoring of load torque.

[0077] When a tire blows out on a vehicle, the corresponding drive motor's speed suddenly increases. This change in drive motor speed or wheel speed allows detection of the blown-out wheel among the four. When a tire blows out, the tire pressure drops; if the tire pressure falls below a certain threshold, a blowout can be identified.

[0078] According to the solution in this application, tire blowout detection and identification are performed by utilizing the characteristics of distributed motor speed change and load torque change. This shortens the tire blowout detection time, allows for timely intervention and control, reduces the false judgment rate and control difficulty, and improves vehicle safety.

[0079] Secondly, this application provides a vehicle controller for tire blowout stability control, which is used to execute the control methods described in the first aspect and its various implementations.

[0080] The vehicle controller in this application can be a motor controller for an electric vehicle, a vehicle controller, or a separately configured controller with control capabilities. This vehicle controller is applicable to electric or hybrid vehicles, where the electric vehicle can have a distributed motor or centralized motor architecture, possessing multiple drive motors and multiple motor controllers. The vehicle controller can be any one of these multiple motor controllers.

[0081] Thirdly, this application provides an electric vehicle including a vehicle controller, a braking system, an accelerator pedal, a brake pedal, and a steering wheel as described in the second aspect, wherein the accelerator pedal is used to indicate the output of driving torque to the wheels of the electric vehicle, the brake pedal is used to indicate the output of braking force to the wheels of the electric vehicle, and the steering wheel angle is used to indicate the steering angle of the two front wheels.

[0082] Other beneficial effects can be found in the description of the first aspect, and will not be repeated here. Attached Figure Description

[0083] Figure 1 is a schematic diagram of a scenario where an electric vehicle experiences a tire blowout, as provided in an embodiment of this application.

[0084] Figure 2 is a schematic diagram of an electric vehicle provided in an embodiment of this application;

[0085] Figure 3 is a schematic diagram of the architecture of an electric vehicle provided in an embodiment of this application;

[0086] Figure 4 is a schematic diagram of the electric vehicle tire blowout stability control process provided in an embodiment of this application;

[0087] Figure 5 is a schematic diagram of tire blowout stability control for an electric vehicle provided in an embodiment of this application;

[0088] Figure 6 is a schematic diagram of another electric vehicle tire blowout stability control provided in an embodiment of this application;

[0089] Figure 7 is a schematic diagram of another electric vehicle tire blowout stability control provided in an embodiment of this application;

[0090] Figure 8 is a schematic diagram of another electric vehicle tire blowout stability control provided in an embodiment of this application;

[0091] Figure 9 is a schematic diagram of the vehicle controller architecture provided in an embodiment of this application;

[0092] Figure 10 is a schematic diagram of signal interaction for tire blowout stability control of the vehicle controller provided in an embodiment of this application.

[0093] Figure 11 is a schematic flowchart of the vehicle controller tire blowout stability control provided in an embodiment of this application. Detailed Implementation

[0094] 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.

[0095] Tire blowouts at high speeds are a major cause of vehicle loss of control and serious traffic accidents. As the only critical component of a vehicle in direct contact with the ground, tires significantly impact a vehicle's power, braking performance, ride comfort, and handling stability. As shown in Figure 1, when a tire blows out at high speeds, its dynamic characteristics change drastically, disrupting the vehicle's balance and causing it to deviate from its original trajectory, significantly affecting its stability and safety. Therefore, tire blowout detection and stability control are essential.

[0096] In one possible implementation, a tire pressure sensor is used to detect tire blowouts. The sensor monitors tire pressure in real time via Bluetooth, diagnoses the pressure values, and identifies rapid pressure loss, slow pressure loss, and blowouts. Upon detecting a blowout, the Electronic Stability Control (ESC) system controls vehicle stability to prevent loss of control and potential accidents.

[0097] It should be understood that tire pressure-based blowout detection is a second-level signal, slow and with a long detection time, typically 1-3 seconds. This creates a "vacuum period" for vehicle stability intervention. During this time, the vehicle veers towards the blown tire, and as tire pressure drops rapidly, the lateral deviation worsens, causing driver panic. With the second-level delay in tire pressure-based blowout detection, the vehicle has already veered off course, and an ESC system with a 100ms closed-loop cycle cannot quickly and accurately correct the vehicle's movement. Using a single ESC for stability control results in a long control time and low control bandwidth, requiring the driver to quickly perceive the vehicle's state and make adjustments. Novice drivers often struggle with steering corrections and deceleration, and excessive corrections can easily lead to accidents.

[0098] To address the aforementioned issues, this application provides an electric vehicle control method, vehicle controller, and electric vehicle for tire blowout stability control. Upon detecting a tire blowout in the electric vehicle, the method rapidly adjusts the torque, quickly clearing the drive torque and braking force of the blown wheel to zero, providing sufficient margin for steering lateral force, making it easier to achieve stable control, and improving the vehicle's safety and stability.

[0099] Figures 2 and 3 are schematic diagrams of the architecture of the electric vehicle 10 provided in the embodiments of this application.

[0100] As shown in Figure 2, the electric vehicle 10 includes a vehicle controller 20, a drive motor 30, a motor controller 40, a braking system 60, a power battery (not shown in the figure), and multiple wheels. The motor controller 40 is used to output current to the drive motor 30 to control the output torque of the drive motor 30 to drive the electric vehicle 10.

[0101] 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.

[0102] Among them, electric vehicles 10 include, but are not limited to, pure electric vehicles (battery electric vehicles, pure EVs / battery EVs), hybrid electric vehicles (HEVs), range-extended electric vehicles (REEVs), plug-in hybrid electric vehicles (PHEVs), and new energy vehicles (NEVs).

[0103] The power battery in this application embodiment 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 to any particular type. The power battery can also supply power to other electrical components in the vehicle, such as the vehicle's air conditioning system and in-vehicle media player.

[0104] The electric vehicle 10 can be a distributed four-motor drive architecture, with the drive motors positioned beside the driving wheels and controlled by individual motor controllers 40. Alternatively, the electric vehicle can have a centralized drive motor architecture, where the drive motors for the two front wheels or two rear wheels are grouped 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.

[0105] In one embodiment, as shown in FIG3(a), the electric vehicle 10 may be a distributed four-motor drive architecture, with the drive motors positioned beside the driving wheels and controlled by separate motor controllers. Alternatively, the electric vehicle 10 may be a centralized four-motor drive architecture, as shown in FIG3(b), where two drive motors for driving the two front wheels or the two rear wheels are positioned together.

[0106] 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 31, drive motor 32, drive motor 33, and drive motor 34. Motor controller 41 controls drive motor 31 to drive wheel 51, motor controller 42 controls drive motor 32 to drive wheel 52, motor controller 43 controls drive motor 33 to drive wheel 53, and motor controller 44 controls drive motor 34 to drive wheel 54.

[0107] Based on their position, the wheels can be divided into left front wheels, right front wheels, left rear wheels, and right rear wheels. According to axle arrangement, the left and right front wheels are on the same axle and connected via the front axle, while the left and right rear wheels are on the same axle and connected via the rear axle. According to their position, the left and left rear wheels are on the same side (left side), and the right front and right rear wheels are on the same side (right side). In other words, in the electric vehicle 10, the left and right front wheels are co-axled, the left and right rear wheels are co-axled; the left and left rear wheels are on the same side, the right and right rear wheels are on the same side; the left and right rear wheels are diagonally opposite each other, and the right and left rear wheels are diagonally opposite each other. For example, if the left front tire blows out while the electric vehicle is in motion, the tire on the same side as the tire that blows out is the left rear tire, the tire on the opposite side of the tire that blows out is the right front tire and the right rear tire, the tire on the same axle as the tire that blows out is the right front tire, and the tire diagonally opposite the tire that blows out is the right front tire.

[0108] Similarly, of the four drive motors, the two motors driving the two front wheels are coaxial, and the two drive motors driving the two front wheels are also coaxial. Of the four drive motors, the two motors driving the two left wheels are on the same side, and the two drive motors driving the two right wheels are also on the same side.

[0109] In one embodiment, the electric vehicle 10 may also be a centralized drive motor architecture as shown in Figure 3(c), with one drive motor driving the two front wheels of the electric vehicle 10 and two drive motors driving the two rear wheels of the electric vehicle 10 respectively.

[0110] In one embodiment, the various architectures mentioned above can also be combined, for example, the front drive adopts a distributed drive motor architecture and the rear drive adopts a centralized drive motor architecture.

[0111] In one embodiment, the braking system 60 includes a brake controller and a plurality of wheel-end braking devices, the brake controller being signal-connected to the brake pedal. The brake controller can be used to determine the braking force based on the opening degree of the brake pedal. During driving, when the electric vehicle 10 needs to brake, the driver depresses the brake pedal. The brake controller receives the brake pedal signal from the brake pedal and outputs a braking force distribution signal to the wheel-end braking devices. The wheel-end braking devices receive the braking force distribution signal and output clamping force to the brake disc according to the indication of the braking force distribution signal, thereby generating frictional braking force, causing the electric vehicle 10 to brake.

[0112] The vehicle controller provided in this application can be any one of multiple motor controllers.

[0113] The electric vehicle 10 also includes an accelerator pedal, a brake pedal, and a steering wheel. The accelerator pedal is used to indicate the torque output to the wheels of the electric vehicle 10. The brake pedal is used to indicate the braking force output to the wheels of the electric vehicle 10, and the steering wheel angle is used to indicate the steering angle of the two front wheels.

[0114] 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.

[0115] 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.

[0116] In one embodiment, the vehicle controller 20 is connected to the brake pedal via a signal interface. The vehicle controller 20 calculates the vehicle braking demand based on the brake pedal opening of the electric vehicle 10 during driving and sends a braking signal to the brake controller based on the vehicle braking demand. The brake controller controls the corresponding wheel-end braking device to output braking force to brake the corresponding wheel according to the indication of the braking signal.

[0117] In one embodiment, the vehicle controller 20 can also be directly connected to the brake pedal and control the wheel-end braking device to output braking force according to the opening degree of the brake pedal.

[0118] In one embodiment, each motor controller 40 uses a resolver sensor via a signal interface. The resolver sensor detects the rotational speed of the drive motor 30 controlled by the motor controller 40, and the motor controller 40 receives signals from the resolver sensor. The motor controller 40 can also generate a rotational speed signal based on the signals from the resolver sensor and send the rotational speed signal to the other three motor controllers 40. Similarly, each motor controller 40 also receives rotational speed signals from the other three motor controllers 40.

[0119] The resolver sensor can accurately detect the position, direction and speed of the motor rotor, and is responsible for monitoring and extracting the rotational speed of the drive motor. It has a high sampling rate and is directly connected to the motor controller 40, resulting in short signal transmission time and higher stability.

[0120] In one embodiment, the motor controller 40 also acquires vehicle signals from the vehicle controller 20 or other sensors of the electric vehicle 10 via a signal interface. The vehicle signals are used to indicate the speed, yaw rate, and tire pressure of each wheel of the electric vehicle 10.

[0121] In one embodiment, the electric vehicle 10 also includes a rear-wheel steering system for controlling the steering angle of the rear wheels of the electric vehicle 10. The rear-wheel steering system can change the rotation angle and orientation of the two rear wheels, thereby effectively adjusting the vehicle's steering and handling characteristics through different steering methods. At low vehicle speeds, when the rear wheels are steered in the opposite direction to the front wheels, the turning radius can be reduced, improving the overall handling and agility of the vehicle. At higher vehicle speeds, when the rear wheels are steered in the same direction as the front wheels, the yaw moment generated by steering operations can be effectively reduced, enhancing vehicle stability.

[0122] Rear-wheel steering provides vehicles with greater control margins, improving handling and agility at low speeds while enhancing stability at high speeds and reducing the risk of loss of control.

[0123] In one embodiment, the suspension system of the electric vehicle 10 includes a variable damping shock absorber. The variable damping shock absorber is a damper that can adjust the damping force of the shock absorber according to the vehicle's driving conditions through an electronically controlled method, for example, by changing the flow resistance of the fluid inside the shock absorber to adjust the damping force, thereby changing the response characteristics of the suspension system.

[0124] In one embodiment, the suspension system of the electric vehicle 10 includes air springs, which can adjust the vehicle height by inflating and deflating the air springs to provide a comfortable ride and good handling performance.

[0125] In one embodiment, the motor controller 40 can connect to the vehicle controller 20, the suspension system, and the steering system via a controller area network (CAN) bus, a local interconnect network (LIN) bus, a high-speed fault-tolerant network protocol (FlexRay), or other types of connection methods, and exchange signals.

[0126] To facilitate understanding of the control method and vehicle controller for reducing cornering roll provided in the embodiments of this application, the control method and vehicle controller for tire blowout stability control provided in the embodiments of this application will be described below with reference to Figure 4 at the first time t1, the second time t2, the third time t3, and the fourth time t4 after a tire blowout of an electric vehicle.

[0127] 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.

[0128] While the electric vehicle 10 is traveling at a speed exceeding a preset speed, one of its wheels experiences a tire blowout. At the first moment t1, the electric vehicle 10 detects that one of its wheels has blown out.

[0129] In one embodiment, a tire blowout occurs on one wheel of the electric vehicle 10, including when the load torque of one wheel is greater than a preset value, and / or when the tire pressure of one wheel is less than a pressure threshold, and / or when the wheel speed of one wheel increases more than the wheel speed of other wheels within a preset time period.

[0130] The electric vehicle 10 can obtain signals representing the vehicle's driving status, such as vehicle speed, steering wheel angle, yaw rate, and tire pressure, from vehicle sensors such as vehicle speed sensor, steering wheel angle sensor, inertial sensor, and tire pressure sensor, and complete tire blowout detection and tire blowout wheel positioning based on these signals.

[0131] In this embodiment, load torque refers to the torque applied to the drive motor by an external load. It is the torque that the drive motor needs to overcome in order to move the vehicle or maintain its motion. Load torque includes rolling resistance, air resistance, gradient resistance, and the additional torque required for acceleration.

[0132] The load torque of a tire that has blown out increases dramatically, exhibiting a large step fluctuation within a short period, followed by a significant increase in torque value after stabilization. This characteristic can be used to detect tire blowouts. Load torque can be observed using a load monitor. By measuring the drive motor speed through a resolver signal, the load torque can be calculated, thus enabling the observation of load torque.

[0133] When a tire blows out on one of the vehicle's wheels, the speed of the corresponding drive motor will suddenly increase. By observing the changes in the drive motor speed or the wheel speed, the wheel that has blown out can be detected.

[0134] Load observation based on the resolver signal from the resolver sensor and the output torque signal from the drive motor can achieve tire blowout detection at the microsecond (µs) level. This allows for precise determination of tire load changes based on the resolver signal and drive torque of the drive motor, thus enabling tire blowout detection.

[0135] When a tire blows out, the tire pressure will drop. When the tire pressure is lower than the pressure threshold, it can be determined that the tire has blown out.

[0136] The tire blowout detection and control are only performed when the speed of the electric vehicle 10 exceeds the preset speed, to avoid misjudgment and miscontrol during vehicle start-up acceleration or low-speed driving. The preset speed can be pre-calibrated based on actual vehicle experiments and / or model calculations, or it can be preset by comprehensively considering the overall vehicle requirements and performance.

[0137] As shown in Figure 4, at the first moment t1, the wheel speed of the tire that bursts undergoes a sudden change. If the increase in wheel speed within a preset time period is greater than the increase in wheel speed of other wheels, then it can be determined that a tire burst has occurred.

[0138] At the first moment t1, the driving torque of one wheel is reduced and the braking force output by the braking system 60 of the electric vehicle 10 to one wheel is reduced.

[0139] In one embodiment, after a first moment t1, the driving torque of one wheel is reduced to zero and the braking force output by the braking system 60 of the electric vehicle 10 to one wheel is reduced to zero.

[0140] A tire blowout will produce a blowout braking effect, causing a sudden increase in rolling resistance, a decrease in wheel radius, and unequal forces on the left and right wheels of the drive axle. This generates yaw torque, causing the vehicle's direction of travel to veer, and the electric vehicle 10 will yaw towards the side of the blown tire. To control the yaw caused by the tire blowout, it is necessary to ensure that the wheels receive sufficient lateral force. Resetting the torque of the blown tire to zero can provide sufficient margin for the electric vehicle 10's steering lateral force.

[0141] According to the solution of this application, when the electric vehicle 10 experiences a tire blowout, the torque and braking force are quickly adjusted to zero, making full use of the lateral force friction limit, providing sufficient margin for steering lateral force, facilitating directional stability control, and improving vehicle safety.

[0142] In one embodiment, the control method further includes: after a first moment t1, controlling the suspension system of the electric vehicle 10 to adjust the damping of the shock absorber of one wheel to increase.

[0143] The suspension system connects the electric vehicle 10 body to the wheels, providing support, cushioning, and stability during the electric vehicle 10's operation. The suspension system may include shock absorbers. Each wheel can be individually connected to the electric vehicle body via a shock absorber. For suspension systems with adjustable damping shock absorbers, when a tire blowout occurs in the electric vehicle 10, a target damping coefficient or target damping level can be sent to the suspension system to adjust the damping of each shock absorber. For the shock absorber of the blown-out wheel, the damping of the shock absorber can be increased; by applying stronger damping, the wheel's contact with the road surface is maintained. For other wheels, the damping of the shock absorbers may or may not be changed.

[0144] In one embodiment, the control method specifically includes: after a first moment t1, controlling the suspension system of the electric vehicle 10 to adjust the damping of the shock absorber of one wheel to increase to a target damping, the target damping increasing as the speed of the electric vehicle 10 increases.

[0145] When an electric vehicle experiences a tire blowout while driving, the higher the vehicle's speed, the greater the force required to stabilize the vehicle. Therefore, adjusting the wheels to the target position with greater damping can provide sufficient support.

[0146] In one embodiment, the control method further includes: after a first moment t1, controlling the suspension system of the electric vehicle 10 to adjust the body height of one wheel to be greater than the body height of the other wheels of the electric vehicle 10.

[0147] The suspension system can include air suspension or fully active suspension. When an electric vehicle experiences a tire blowout, the suspension system can send a target wheel suspension height signal, allowing adjustment of the suspension height at that wheel. In one implementation, the air suspension can control the lowering of the suspension height at the non-blowout wheel while maintaining a constant suspension height at the blowout wheel, thus ensuring the vehicle's height at the blowout wheel is greater than that of the other wheels. In another implementation, the fully active suspension can control the raising or lowering of the suspension height at each wheel. For the blowout wheel, the fully active suspension can control the raising of the vehicle's height at that wheel, ensuring it is greater than the height of the other wheels, thereby elevating the blowout wheel. For the suspension height of the non-blowout wheels, the fully active suspension can adjust the height according to the balance of the electric vehicle's body posture.

[0148] Referring to Figure 4, at the second time t2 after the first time t1, the accelerator pedal of the electric vehicle 10 is opened to a greater degree than the preset accelerator pedal opening.

[0149] The control method specifically includes: controlling the driving torque of the wheel on the same side of a wheel to be greater than the driving torque of the wheel diagonally opposite the wheel of a wheel.

[0150] At the second moment t2, the driver presses the accelerator pedal. At this time, the drive system controlling the electric vehicle 10 outputs drive torque to generate unequal drive torque on the left and right wheels of the non-exploded axle, thereby achieving yaw suppression.

[0151] It should be understood that the second moment t2 and the first moment t1 can be very close. In the process of controlling the driving torque of one wheel to be reduced to zero and controlling the braking force output by the braking system of the electric vehicle to one wheel to be zero, the driving torque of the wheel on the same side of one wheel and the driving torque of the wheel diagonally opposite one wheel can be adjusted.

[0152] By controlling one or both of the two drive motors on the left and right sides to work simultaneously, different magnitudes of drive torque are generated. This allows for torque vector control of the two drive motors to generate yaw correction torque, thereby suppressing the yaw of the entire vehicle.

[0153] In one embodiment, the control method specifically includes: when the left front wheel of the electric vehicle 10 blows out, at a second time t2, controlling the driving torque of the left rear wheel of the electric vehicle 10 to be greater than the driving torque of the right rear wheel.

[0154] When the right front tire of the electric vehicle 10 blows out, at the second moment, the driving torque of the left rear wheel of the electric vehicle is reduced to that of the right rear wheel.

[0155] For example, as shown in Figure 5, when the right front tire of the electric vehicle 10 blows out, the right front tire will produce a blowout braking effect. If the driver does not apply steering wheel control, the electric vehicle 10 will generate a yaw moment to the right (clockwise relative to the vehicle). At this time, the electric vehicle 10 detects that the driver has pressed the accelerator pedal at the second time t2, and controls the driving torque of the right rear wheel to be greater than the driving torque of the left rear wheel, so that the electric vehicle 10 generates a yaw correction moment to the left (counterclockwise relative to the vehicle), thereby reducing the yaw of the electric vehicle 10.

[0156] In one embodiment, the control method specifically includes: at a second time t2, controlling the difference between the driving torque of a wheel on the same side of a wheel and the driving torque of a wheel diagonally opposite a wheel to increase as the speed of the electric vehicle 10 increases.

[0157] When a tire blows out during the operation of the electric vehicle 10, the greater the speed of the electric vehicle 10, the greater the yaw rate deviation caused by the tire blowout, the greater the yaw correction torque required for tire blowout stability control, and the greater the torque differential output of the left and right drive motors of the non-blowout axle.

[0158] In one embodiment, the control method further includes: at a second time t2, when the opening of the accelerator pedal of the electric vehicle 10 is greater than a preset accelerator opening, controlling the steering system of the electric vehicle 10 to adjust the steering angle of the two rear wheels.

[0159] The steering system of the electric vehicle 10 can control the steering of the rear wheels. The steering system can change the rotation angle and orientation of the two rear wheels, allowing the electric vehicle 10 to effectively adjust its steering and handling characteristics through different steering methods. When the electric vehicle 10 is in motion, if one front tire blows out, the blown wheel will experience a blowout braking effect, causing a sudden increase in wheel speed and a veer in the vehicle's direction of travel. The electric vehicle 10 will yaw towards the side of the blown front wheel. To ensure the safety of the driver and the vehicle, the rear-wheel steering system can adjust the steering of the two rear wheels to generate a yaw control torque. This yaw control torque counteracts the yaw caused by the tire blowout, reducing the vehicle's yaw amplitude.

[0160] In one embodiment, the control method specifically includes: when the left front wheel of the electric vehicle 10 blows out, at a second moment t2, controlling the steering system of the electric vehicle 10 to adjust the two rear wheels to turn to the left.

[0161] The right front tire of electric vehicle 10 blows out. At the second moment t2, the steering system of electric vehicle 10 is controlled to adjust the two rear wheels to turn to the right.

[0162] For example, as shown in Figure 6, when the right front tire of electric vehicle 10 blows out, if the driver does not apply steering wheel control, the electric vehicle will generate a yaw moment to the right (clockwise relative to the vehicle). At this time, electric vehicle 10 detects that the driver has pressed the accelerator pedal at the second moment t2 and controls the rear wheel steering system to turn to the right. The rightward steering of the rear wheels can cause electric vehicle 10 to generate a yaw control moment to the left (counterclockwise relative to the vehicle). The yaw moment and the yaw control moment cancel each other out, and the yaw amplitude of electric vehicle 10 is reduced.

[0163] In one embodiment, the control method specifically includes: at a second time t2, controlling the steering system of the electric vehicle 10 to adjust the steering angle of the two rear wheels to decrease as the speed of the electric vehicle 10 increases.

[0164] The faster the vehicle speed, the higher the risk of a tire blowout, and the greater the impact on the vehicle's attitude and trajectory. At this time, the yaw control torque applied by steering will also be greater, and the danger will also be greater. The higher the speed, the easier it is to lose control. Therefore, the higher the speed, the smaller the steering angle of the rear wheel steering system.

[0165] In one embodiment, the control method further includes: at a second time t2, when the opening of the accelerator pedal of the electric vehicle 10 is greater than a preset accelerator opening and the change in steering wheel angle is greater than a steering threshold, controlling the steering system of the electric vehicle 10 to adjust the steering angle of the two front wheels to be less than the steering angle indicated by the steering wheel angle.

[0166] In one embodiment, the control method further includes: at a second time t2, when the opening of the accelerator pedal of the electric vehicle 10 is greater than a preset accelerator opening and the change in steering wheel angle is greater than a direction threshold, controlling the steering system to adjust the two rear wheels to turn in the opposite direction to the steering angle indicated by the steering wheel angle.

[0167] When a tire blows out in electric vehicle 10, if the driver presses the accelerator pedal and the vehicle is still moving, the driver may make a sharp steering correction upon sensing the blowout. This action could exacerbate the safety risk of the blowout. Therefore, when the steering wheel angle exceeds a certain threshold, appropriate suppression strategies are needed to control the steering system, suppress changes in the front wheel steering angle, limit the steering wheel rotation rate, and prevent risks caused by sudden steering. Rear wheel steering is then used to assist the driver in achieving the steering objective; the direction of rear wheel steering is opposite to that of the front wheels and the direction of the steering wheel.

[0168] For example, as shown in Figure 7, when the right front tire of electric vehicle 10 blows out, the electric vehicle will generate a yaw moment to the right (clockwise relative to the vehicle). At this time, electric vehicle 10 detects at the second moment t2 that the driver has pressed the accelerator pedal and the driver has turned the steering wheel sharply to the left. At this time, the steering system controls the rate of change of the front wheel steering angle to the left and controls the two rear wheels to turn to the right. The rightward turning of the rear wheels can cause electric vehicle 10 to generate a yaw control moment to the left (counterclockwise relative to the vehicle), and assist the driver in changing lanes to the left.

[0169] Referring to Figure 4, at the third time t3 after the first time t1, the opening of the brake pedal of the electric vehicle 10 is greater than the preset brake opening.

[0170] The control method also includes controlling the braking force output by the braking system 60 to the wheel on the same side of a wheel to be less than the braking force output to the wheel diagonally opposite to a wheel.

[0171] At the third moment t3, the opening of the brake pedal of the electric vehicle 10 is greater than the preset braking opening. At this time, the driver presses the brake pedal, controlling the braking system 60 of the electric vehicle 10 to output unequal braking forces to the left and right wheels of the non-exploded axle, generating yaw moment, thereby suppressing the yaw caused by the tire blowout.

[0172] It should be understood that there is usually a period of time between the occurrence of a tire blowout in the electric vehicle 10 and the driver's awareness of the blowout. During this time, the driver maintains the previous driving posture and continues to press the accelerator pedal. When the driver notices the blowout and intervenes, they may continue to press the accelerator pedal to try to maintain the vehicle speed, or they may press the brake pedal to try to stop the vehicle. Therefore, the second moment t2 usually occurs during the entire blowout stabilization and control process, while the third moment t3 may not occur during the blowout process, and the third moment t3 usually occurs after the second moment t2.

[0173] In one embodiment, the control method specifically includes: when the left front wheel of the electric vehicle 10 blows out, at a third moment t3, controlling the braking force output by the braking system 60 to the left rear wheel of the electric vehicle 10 to be less than the braking force output to the right rear wheel.

[0174] The right front tire of electric vehicle 10 blows out. At the third moment t3, the braking force output by the control braking system 60 to the left rear wheel of electric vehicle 10 is greater than the braking force output to the right rear wheel.

[0175] For example, as shown in Figure 8, when the right front tire of the electric vehicle 10 blows out, if the driver does not apply steering wheel control, the electric vehicle 10 will generate a yaw moment to the right (clockwise relative to the vehicle). At this time, the electric vehicle 10 detects that the driver has pressed the brake pedal at the third moment t3, and controls the braking system 60 to output a greater braking force to the left rear wheel than to the right rear wheel, causing the electric vehicle to generate a yaw correction moment to the left (counterclockwise relative to the vehicle), thereby reducing the yaw of the electric vehicle.

[0176] In one embodiment, the control method specifically includes: at a third time t3, controlling the difference between the braking force output by the braking system 60 to the wheel on the same side of a wheel and the braking force output to the wheel diagonally opposite a wheel to increase with the increase of the speed of the electric vehicle 10.

[0177] When an electric vehicle 10 experiences a tire blowout while driving, the higher the speed of the electric vehicle 10, the greater the yaw rate deviation caused by the tire blowout, the greater the yaw correction torque required for tire blowout stability control, and the greater the difference in braking force between the left and right wheels of the non-blowout axle.

[0178] In one embodiment, at a third time t3, the opening of the brake pedal of the electric vehicle 10 is greater than a preset braking opening, and the difference between the driving torque of the wheel on the same side of one wheel and the driving torque of the wheel diagonally opposite to one wheel is reduced to zero.

[0179] Referring to Figure 4, at the fourth time t4 after the first time t1, the speed of electric vehicle 10 is less than the safety threshold.

[0180] The control method includes: in response to the electric vehicle 10's speed being less than a safety threshold, controlling the braking system 60 to reduce the difference between the braking force output to the wheel on the same side of a wheel and the braking force output to the wheel diagonally opposite a wheel to zero.

[0181] At the fourth moment t4, the speed of electric vehicle 10 is reduced to a safe range or has stopped. At this time, the difference in control drive torque is reduced to zero, and the difference in control braking force between the left and right wheels is also reduced to zero.

[0182] According to the solution in this application, by precisely calculating the timing of torque intervention required by the motor controller 40, the torque output of the drive motor 30 is instantaneously adjusted, quickly clearing the drive torque and braking force to zero, providing sufficient margin for steering lateral force, and facilitating directional stability control. Based on the principle of minimizing the time delay of multi-component coordination, the generation of vehicle yaw torque is achieved, suppressing yaw caused by axle blowout and stabilizing the vehicle's posture.

[0183] The control architecture of the vehicle controller and the control signal for tire blowout stability control provided in the embodiments of this application will be described below with reference to Figures 9, 10 and 11.

[0184] The vehicle controller comprises two parts: tire blowout detection and coordinated control.

[0185] As shown in Figures 9 and 11, during tire blowout detection, the vehicle controller receives resolver signals from the resolver sensor, accelerator pedal opening signals, brake pedal opening signals, and drive torque signals. By calculating the road surface adhesion conditions of the front and rear wheels, it identifies the tire blowout scenario and locates the blown-out wheel. Once a tire blowout is detected, a blowout signal is sent to multiple systems and components, indicating the location of the blown-out wheel and the location of the blown-out tire.

[0186] As shown in Figures 10 and 11, after determining a tire blowout, the vehicle controller sends a blowout signal and a torque distribution signal to multiple motor controllers. The drive torque of the motor driving the blown tire is limited, and the other drive motors are controlled to apply yaw correction torque.

[0187] The vehicle controller sends a tire blowout signal and a brake force distribution signal to the braking system 60. Braking force is limited on the blown tire, while yaw correction torque is applied to the non-blowout tires to keep the vehicle from veering off course.

[0188] For vehicles with adjustable damping shock absorbers, the vehicle controller sends a tire blowout signal and provides a target damping coefficient or target damping level setting. For systems with air springs, it sends a tire blowout signal, adjusts the air spring of the blown wheel, and provides a target height adjustment setting to raise the height of the blown wheel; for non-blowout wheel air spring adjustments, it provides a target height adjustment setting based on the vehicle's attitude balance.

[0189] The vehicle controller sends a tire blowout signal to the steering system and limits the steering wheel rotation rate to prevent risks caused by sudden steering wheel movements. For the rear-wheel steering system, it sends a tire blowout signal and provides the rear wheel steering angle.

[0190] Referring to Figure 4, in one embodiment, the vehicle controller calculates the road surface adhesion of the front and rear drives based on the resolver signal from the resolver sensor, identifies the tire blowout, locates the blown wheel, and sends a blowout signal to multiple systems and components. The blowout signal indicates the location of the blown wheel and the blown tire. At the first time t1, the vehicle controller sends a torque signal to the drive system and a braking force distribution signal to the braking system. The torque signal controls the drive torque of the blown tire to be reduced to zero, and the braking force distribution signal controls the braking force output by the braking system to one wheel to be zero, thereby providing a margin for vehicle control. At the second time t2, the accelerator pedal opening is greater than the preset accelerator pedal opening. The torque signal controls the drive torque of the wheel on the same side as the blown tire to be greater than the drive torque of the wheel diagonally opposite the blown tire. The difference in drive torque between the left and right sides suppresses the yaw caused by the blowout. When the steering wheel angle change is greater than a steering threshold, the vehicle controller also sends a steering signal to the steering system to control the electric vehicle's steering system to adjust the steering angle of the two front wheels to be less than the steering angle indicated by the steering wheel angle, and controls the steering system to adjust the steering angle of the two rear wheels. This suppresses sharp steering wheel movements by the driver and utilizes rear-wheel steering to assist the electric vehicle's steering, improving its maneuverability and reducing the risk of loss of control. At the third moment t3, the brake pedal opening is greater than the preset brake opening, and the braking force distribution signal controls the braking force output by the braking system 60 to the wheel on the same side as the blown tire to be less than the braking force output to the diagonally opposite wheel. The torque signal controls the difference between the driving torque of the wheel on the same side as the blown tire and the driving torque of the diagonally opposite wheel to reduce it to zero. After the first moment t1, the vehicle controller sends a target damping coefficient or target height adjustment signal to the suspension system to control the suspension system to either increase the damping of the shock absorber on the blown tire or adjust the vehicle height of the blown tire to be greater than the vehicle height of the other wheels of the electric vehicle. At the fourth moment t4, the electric vehicle's speed is less than the safety threshold, and the braking force distribution signal controls the difference between the braking force output by the braking system 60 to the wheel on the same side as the blown tire and the braking force output to the diagonally opposite wheel to reduce it to zero.

[0191] According to the solution in this application, tire blowout detection is achieved based on the load observation of the drive motor, without relying on tire pressure sensors, significantly accelerating the detection cycle from seconds to milliseconds. Upon detecting a blowout, the system actively reduces torque, achieving rapid torque adjustment and increasing the safety threshold. The system controls a multi-motor distributed drive architecture, braking system, rear-wheel steering system, and suspension system, achieving multi-system corrective joint control to ensure vehicle stability. This can suppress safety risks caused by driver error while simultaneously achieving the driver's driving objectives safely through the intervention of other systems.

[0192] 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 when one wheel of the electric vehicle occurs tire burst during driving process with vehicle speed greater than preset vehicle speed, and the control method comprises: At a first time after the one wheel of the electric vehicle occurs tire burst, the control method comprises:

2. The control method according to claim 1, characterized by, Controlling the driving torque of the one wheel to decrease and controlling the braking force outputted by the braking system of the electric vehicle to the one wheel to decrease. The control method specifically comprises:

3. The control method according to claim 1 or 2, characterized by, After the first time, the control method comprises: Controlling the driving torque of the one wheel to decrease to zero and controlling the braking force outputted by the braking system of the electric vehicle to the one wheel to decrease to zero.

4. The control method according to claim 3, characterized by, The control method specifically comprises: At a second time after the first time, the control method comprises: The opening degree of the accelerator pedal of the electric vehicle is greater than preset accelerator opening degree, and the control method comprises:

5. The control method according to claim 3 or 4, characterized by, Controlling the driving torque of the same side wheel of the one wheel to be greater than the driving torque of the diagonal wheel of the one wheel. The control method specifically comprises:

6. The control method according to any one of claims 1 to 5, characterized by, When the left front wheel of the electric vehicle occurs tire burst, at the second time, the control method comprises: Controlling the driving torque of the left rear wheel of the electric vehicle to be greater than the driving torque of the right rear wheel; 7. The control method according to claim 6, characterized by When the right front wheel of the electric vehicle occurs tire burst, at the second time, the control method comprises: Controlling the driving torque of the left rear wheel of the electric vehicle to be less than the driving torque of the right rear wheel. The control method specifically comprises:

8. The control method according to claim 6 or 7, characterized by, At the second time, the control method comprises: Controlling the difference between the driving torque of the same side wheel of the one wheel and the driving torque of the diagonal wheel of the one wheel to increase with the increase of the vehicle speed of the electric vehicle.

9. The control method according to any one of claims 1 to 8, characterized by, The control method further comprises: At a third time after the first time, the control method comprises:

10. The control method according to claim 9, characterized by, The opening degree of the brake pedal of the electric vehicle is greater than preset brake opening degree, and the control method comprises: Controlling the braking force outputted by the braking system to the same side wheel of the one wheel to be less than the braking force outputted to the diagonal wheel of the one wheel.

11. The control method according to any one of claims 1 to 8, characterized by, The control method specifically comprises: When the left front wheel of the electric vehicle occurs tire burst, at the third time, the control method comprises:

12. The control method according to any one of claims 1-11, characterized by, Controlling the braking force outputted by the braking system to the left rear wheel of the electric vehicle to be less than the braking force outputted to the right rear wheel; When the right front wheel of the electric vehicle occurs tire burst, at the third time, the control method comprises: Controlling the braking force outputted by the braking system to the left rear wheel of the electric vehicle to be greater than the braking force outputted to the right rear wheel. The control method specifically comprises: At the third time, the control method comprises: Controlling the difference between the braking force outputted by the braking system to the same side wheel of the one wheel and the braking force outputted to the diagonal wheel of the one wheel to increase with the increase of the vehicle speed of the electric vehicle. The control method further comprises: After the first time, the control method comprises: Controlling the suspension system of the electric vehicle to adjust the damping of the shock absorber of the one wheel to increase. The control method further comprises: After the first time, the control method comprises: Controlling a suspension system of the electric vehicle to adjust a body height of the one wheel to be greater than a body height of other wheels of the electric vehicle. The control method further comprises: At a second time after the first time, an opening degree of an accelerator pedal of the electric vehicle is greater than a preset accelerator opening degree, and the control method further comprises:

13. The control method according to claim 12, characterized by, The control method specifically comprises: At the second time, a left front wheel of the electric vehicle has a tire burst, and the control method further comprises: At the second time, a right front wheel of the electric vehicle has a tire burst, and the control method further comprises:

14. The control method according to claim 12 or 13, characterized by, The control method specifically comprises: At the second time, the control method further comprises:

15. The control method according to any one of claims 1-11, characterized by, At a second time after the first time, an opening degree of an accelerator pedal of the electric vehicle is greater than a preset accelerator opening degree and a steering wheel angle change is greater than a steering threshold, and the control method further comprises: At the second time, the opening degree of the accelerator pedal of the electric vehicle is greater than the preset accelerator opening degree and the steering wheel angle change is greater than the steering threshold, and the control method further comprises:

16. The control method according to claim 15, characterized by At the second time, the opening degree of the accelerator pedal of the electric vehicle is greater than the preset accelerator opening degree and the steering wheel angle change is greater than the steering threshold, and the control method further comprises: At a third time after the first time, an opening degree of a brake pedal of the electric vehicle is greater than a preset brake opening degree, and the control method further comprises:

17. The control method according to any one of claims 6-8, characterized by, At a fourth time after the first time, in response to a vehicle speed of the electric vehicle being less than a safety threshold, the control method further comprises: The one wheel of the electric vehicle has a tire burst, including: The load torque of the one wheel is greater than a preset value, and / or the tire pressure of the one wheel is less than a pressure threshold, and / or an increase in a wheel speed of the one wheel within a preset time length is greater than an increase in a wheel speed of other wheels.

18. The control method according to claim 1, characterized by, The vehicle controller is configured to perform the control method according to any one of claims 1 to 18. The electric vehicle comprises the vehicle controller according to claim 19, a brake system, an accelerator pedal, a brake pedal and a steering wheel, the accelerator pedal being configured to indicate output of a drive torque to a wheel of the electric vehicle, the brake pedal being configured to indicate output of a brake force to the wheel of the electric vehicle, and a steering wheel angle of the steering wheel being configured to indicate a steering angle of two front wheels.

19. A vehicle controller characterized by comprising: ​ 20. An electric vehicle characterized by comprising: ​

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