Vehicle controller for tire burst detection, electric vehicle for tire burst control and method

Abstract

The application provides a vehicle controller for tire burst detection, an electric vehicle for tire burst control and a method, and relates to the field of new energy vehicles. The electric vehicle comprises a driving system and a braking system. In a driving process in which the vehicle speed of the electric vehicle is greater than a preset vehicle speed, a tire burst occurs in any one of the four wheels. In response to a sudden change in the wheel speed of any one of the four wheels, the vehicle controller is configured to control the driving system to adjust the driving force or control the braking system to adjust the braking force. The sudden change in the wheel speed of any one of the four wheels refers to that, within a preset time length, the wheel speed increase value of any one of the four wheels is greater than the wheel speed increase values of the other three wheels. According to the scheme, the tire burst is detected based on the rotational speeds of the multiple wheels, the tire burst fault can be quickly detected, the faulty wheel can be positioned, the misjudgment rate is reduced, the control intervention is timely, the control difficulty is reduced, and the vehicle safety is improved.

Description

Technical Field

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

[0002] With the development of the automotive industry and the increasing number of cars year by year, traffic safety accidents are receiving more and more attention. Tires, as the only key component of a car that directly contacts the ground, have a significant impact on the vehicle's power, braking, ride comfort, and handling stability during driving. When a tire blows out at high speed, its dynamic characteristics change drastically, disrupting the vehicle's balance and causing it to deviate from its original trajectory. If the driver panics and takes incorrect actions, the vehicle will directly lose stability, potentially overturning and causing extremely serious consequences. High-speed tire blowouts are one of the main causes of vehicle loss of control and serious traffic accidents. Because most drivers lack experience in handling tire blowout accidents, and may even take inappropriate actions under the influence of external environmental factors and psychological factors, about one-third of traffic accidents on Chinese highways are caused by tire blowouts. In reality, serious high-speed tire blowout accidents often occur within 0.1 seconds, leaving drivers and vehicles with very little time to react and control.

[0003] Tire blowout fault identification and detection, as well as blowout safety control technologies, can greatly improve vehicle driving safety. Currently, the mainstream methods for tire blowout detection and control mainly involve identifying and locating the blowout through tire pressure or wheel speed monitoring, and then using the braking system to control the entire vehicle after the blowout. However, this method has a long detection time, poor real-time performance, untimely control intervention, and poor stability.

[0004] Therefore, improving the speed and accuracy of tire blowout detection and enhancing vehicle safety are urgent issues that need to be addressed. Summary of the Invention

[0005] This application provides a vehicle controller for tire blowout detection, an electric vehicle for tire blowout control, and a method thereof. The vehicle controller detects tire blowout based on the rotational speed of multiple wheels and controls the vehicle in a timely manner. It has high reliability, a lower false alarm rate, can quickly detect tire blowout faults, locate the faulty wheel, and intervene in control in a timely manner, thus reducing the difficulty of control.

[0006] Firstly, this application provides a vehicle controller for tire blowout detection. The vehicle controller is applied to an electric vehicle, which includes a drive system and a braking system. The drive system provides driving force to the four wheels of the electric vehicle, and the braking system provides braking force to the four wheels. When the electric vehicle is traveling at a speed exceeding a preset speed, a tire blowout occurs at any one of the four wheels. In response to this sudden change in wheel speed at any one of the four wheels, the vehicle controller controls the drive system to adjust the driving force or controls the braking system to adjust the braking force. Specifically, a sudden change in wheel speed at any one of the four wheels refers to an increase in the wheel speed of any one of the four wheels exceeding the increase in the wheel speed of the other three wheels within a preset time period.

[0007] The vehicle can have a distributed motor or centralized motor architecture, with multiple motors and multiple motor controllers, where any one of the multiple motor controllers can be used. The motors can be wheel-side motors or wheel hub motors, and each motor can independently drive one wheel of the vehicle.

[0008] The vehicle controller will only perform tire blowout detection and control when the vehicle speed exceeds the preset speed, in order to avoid misjudgment when the vehicle starts to accelerate or is driving at low speed.

[0009] The preset duration can be the sampling time of the wheel speed sensor, the signal interaction time between the vehicle controller and the wheel speed sensor, or a period of time set as needed. The preset duration can be a relatively short period of time. If the rotational speed of one wheel increases rapidly in a short period of time while the wheel speed of other wheels remains relatively constant, a tire blowout may occur.

[0010] When a tire blows out, the wheel's rotational speed suddenly increases due to the braking effect. Therefore, the vehicle controller can determine whether a tire blowout has occurred and locate the wheel that has blown out by using the rotational speed of the blown-out wheel and the rotational speed of other wheels as criteria.

[0011] The vehicle controller connects to the vehicle's four wheel speed sensors via a CAN bus, LIN bus, or hardwired connection. Each wheel speed sensor detects the speed of its corresponding wheel and sends the detected speed data to the vehicle controller. During vehicle operation, if any one of the four wheels experiences a tire blowout, the blown wheel will experience a blowout braking effect, causing a sudden increase in wheel speed and a directional swerve. To ensure driver and vehicle safety, the vehicle's direction needs to be adjusted. Upon detecting a tire blowout, the vehicle controller can control the drive or braking system to apply blowout control based on the required yaw moment, sending a blowout control signal or a blowout braking signal to adjust the vehicle's direction. When the required torque is small, the vehicle controller can send a blowout control signal to the drive system, adjusting the torque output of each drive motor to the three normal wheels. This coordinated torque output to the three normal wheels generates lateral torque, thus controlling the vehicle laterally. When a large torque is required, the vehicle controller can send a tire blowout braking signal to the braking system, thereby controlling the braking force output to the normal wheels.

[0012] According to the solution in this application, the difference in the rotational speed of multiple wheels is considered to improve the reliability of the detection results and reduce the false judgment rate. The rotational speed signals of multiple wheel speed sensors are used for tire blowout detection, which improves the redundancy of the tire blowout detection system, reduces communication latency, shortens the tire blowout detection time, allows for timely intervention and control, reduces control difficulty, and improves vehicle safety.

[0013] In conjunction with the first aspect, in some implementations of the first aspect, the wheel speed of any one of the four wheels suddenly changes, specifically including within a preset time period, the wheel speed increase of any one of the four wheels is greater than a first amplitude, while the wheel speed increase of the other three wheels is less than a second threshold, and the first amplitude is greater than the second amplitude.

[0014] The preset duration can be the sampling period of the resolver sensor, i.e., the time interval between one sample and the next. It can also be the signal interaction time between controllers, or a period of time set as needed. The preset duration can be a relatively short period of time. If the rotational speed of one wheel increases rapidly in a short period of time while the rotational speed of other wheels remains relatively constant, a tire blowout may occur.

[0015] The first and second amplitude values ​​can be set as needed. Different amplitude settings can adjust the sensitivity and false alarm rate of the vehicle controller's tire blowout detection.

[0016] In conjunction with the first aspect, in some implementations of the first aspect, the sudden change in wheel speed of any one of the four wheels also includes the decrease in the driving torque of the wheel whose wheel speed suddenly changes within a preset time period being greater than the third amplitude, and the increase in the driving torque of the wheel whose wheel speed suddenly changes after the preset time period.

[0017] The torque of a wheel that experiences a tire blowout will fluctuate dramatically in a short period of time, and then stabilize with a significant increase in torque value. This characteristic can be used to further determine the cause of the blowout. The vehicle controller can combine wheel speed and the actual torque it receives as judgment criteria. After determining that a wheel with a sudden change in wheel speed has blown out based on its speed, the controller can determine the actual torque received by the wheel with the sudden change in wheel speed. If the torque corresponding to the wheel with the sudden change in wheel speed changes dramatically in a short period of time, then stabilizes and is greater than the torque before the dramatic change (i.e., greater than the third amplitude value), and the driving torque increases after a preset time, then it can be confirmed that the wheel with the sudden change in wheel speed has blown out.

[0018] While the actual torque experienced by a vehicle is difficult to measure, it can be calculated by the vehicle controller. Based on wheel speed, force analysis can be performed using tire kinematic equations for different tires, such as driving or driven tires, to obtain the variation characteristics of the actual tire torque.

[0019] According to the solution in this application, tire blowout detection is performed based on wheel speed and torque information, avoiding misjudging tire slippage or spinning as a blowout. The blowout detection time is short, the reliability is high, and the misjudgment rate is low.

[0020] In conjunction with the first aspect, in some implementations of the first aspect, the four wheels include two wheels on the left and two wheels on the right. Controlling the braking system to adjust the braking force includes, when the wheel whose wheel speed changes abruptly is a left wheel, controlling the braking system to output braking force to at least one of the two right wheels of the electric vehicle. When the wheel whose wheel speed changes abruptly is a right wheel, controlling the braking system to output braking force to at least one of the two left wheels of the electric vehicle.

[0021] When a tire blows out, the vehicle's direction of travel will deviate. To control the vehicle's direction, a lateral torque opposite to the direction of deviation needs to be applied to the vehicle through the normal wheels, thereby adjusting the vehicle's direction. The vehicle controller can calculate the yaw control torque required to adjust the vehicle's direction using input information such as vehicle speed, steering angle, yaw rate, and sideslip angle.

[0022] If the yaw control torque calculated by the vehicle controller to adjust the vehicle's direction of travel is greater than the control threshold, then the motor controller cannot fully control the vehicle's deviation simply by adjusting the output torque of the drive motor. In this case, the vehicle controller needs to send a tire blowout braking signal to output braking force to the corresponding wheels, so that the force on each wheel forms a yaw braking torque. When the yaw braking torque is equal to the deflection torque generated by the tire blowout, and the direction of the yaw braking torque is opposite to the direction of the deflection torque generated by the tire blowout, then the vehicle's direction of travel can be effectively controlled.

[0023] When a tire on a vehicle blows out, a yawing torque is generated in the direction of that wheel. Therefore, it is necessary to control the braking of the wheel on the opposite side of the blown wheel, thereby generating a yaw braking torque in the opposite direction of the yawing torque. The magnitude of the yaw braking torque can be controlled to output braking force to one or both wheels on the opposite side.

[0024] In conjunction with the first aspect, in certain implementations of the first aspect, controlling the braking system to adjust the braking force specifically includes, when the wheel with the sudden change in wheel speed is the left wheel, first controlling the braking system to output braking force to the wheel of the electric vehicle coaxial with the wheel with the sudden change in wheel speed; then controlling the braking system to output braking force to the other right wheel of the electric vehicle. When the wheel with the sudden change in wheel speed is the right wheel, first controlling the braking system to output braking force to the wheel of the electric vehicle coaxial with the wheel with the sudden change in wheel speed; then controlling the braking system to output braking force to the other left wheel of the electric vehicle. The wheel coaxial with the wheel with the sudden change in wheel speed and the wheel with the sudden change in wheel speed are used to drive the two front wheels or the two rear wheels of the electric vehicle.

[0025] When a tire blows out, different control methods can be applied to the normal wheels in different positions. It should be understood that a vehicle typically has four wheels, which can be divided into two wheels on the left and two wheels on the right, and also into two wheels on the front axle and two wheels on the rear axle. When a tire blows out, the wheels in different positions are controlled with different priorities. When applying brakes to a blowout, the wheels on the same axle as the blown wheel but opposite to it have higher control priority than other wheels. When braking two wheels is required, the wheels on the same axle as the blown wheel but opposite to it can be braked first. When braking two wheels is required, the two wheels opposite to the blown wheel should be braked first.

[0026] According to the scheme of this application, a step-by-step control strategy is adopted, and the wheel braking is controlled step by step according to a certain priority. Through precise and efficient control, the vehicle body posture is quickly and effectively adjusted, thereby improving vehicle safety.

[0027] In conjunction with the first aspect, in some implementations of the first aspect, the drive system includes four powertrains, each used to drive one of the four wheels. The two powertrains driving the two left wheels are on the same side, and the two powertrains driving the two right wheels are also on the same side. Controlling the drive system to adjust the driving force specifically includes controlling the powertrain on the side opposite to the wheel with the sudden change in wheel speed to reduce its driving force output; and controlling the powertrain on the same side as the wheel with the sudden change in wheel speed to increase its driving force output.

[0028] When controlling a tire blowout, torque reduction control is prioritized over torque increase control. Wheels on the same axle as the wheel that experienced the blowout but on the opposite side have higher control priority than other motors. Wheels on the opposite side of the blowout wheel can be subject to torque reduction control, i.e., reducing the motor's positive torque output or making the motor output negative torque. Wheels on the opposite side of the blowout wheel can be subject to torque increase control, i.e., increasing the motor's positive torque output.

[0029] It should be understood that during vehicle operation, the amount of torque that the drive motor can increase or decrease on the normal wheels is limited. Therefore, there is an upper limit to the yaw torque that the drive motor of the normal wheels can apply to the vehicle. This upper limit of the yaw torque applied to the vehicle is the control threshold. When the yaw control torque required to adjust the vehicle's direction, calculated by the vehicle controller, is less than or equal to the control threshold, the vehicle controller sends a tire blowout control signal, instructing the drive system to adjust the output torque, specifically the yaw control torque for each wheel. When the yaw control torque equals the deflection torque generated by a tire blowout, and the direction of the yaw control torque is opposite to the direction of the deflection torque generated by a tire blowout, then the vehicle's direction of travel can be effectively controlled.

[0030] In conjunction with the first aspect, in some implementations of the first aspect, the two powertrains driving the two front wheels are coaxial powertrains, and the two powertrains driving the two rear wheels are coaxial powertrains. Controlling the drive system to adjust the driving force sequentially includes first controlling the powertrain coaxial with the wheel corresponding to the wheel with the sudden change in wheel speed to reduce its driving force output; then controlling the powertrain on a different axle and side from the wheel corresponding to the wheel with the sudden change in wheel speed to reduce its driving force output; and finally controlling the powertrain on the same side as the wheel corresponding to the wheel with the sudden change in wheel speed to increase its driving force output.

[0031] Based on the calculated yaw torque required to adjust the vehicle's direction and the magnitude of the maximum yaw control torque of each motor, control is applied step by step to all drive motors. When the output torque of the drive motors is insufficient to adjust the vehicle's direction, braking is applied through the braking system.

[0032] According to the scheme of this application, the control process is divided into two levels based on the required control quantity: motor drive control and braking system control. The first level improves the overall vehicle control effect through the drive system. The required yaw control torque value is used as a reference quantity, and control signals are gradually applied to all motors according to a certain priority. The second level triggers the braking system to intervene when necessary to ensure the reliability of the control system and the safety of the vehicle.

[0033] In conjunction with the first aspect, in some implementations of the first aspect, each of the four powertrains includes a motor controller and a motor, wherein the motor controller controls the output torque of the motor to drive a wheel. A vehicle controller is used to send a torque signal to the motor controller of each powertrain, the torque signal instructing the motor controller to control the output torque of the motor as indicated by the torque signal.

[0034] Secondly, this application provides an electric vehicle with tire blowout control. The electric vehicle includes a drive system and a braking system. The drive system provides driving force to the four wheels of the electric vehicle, and the braking system provides braking force to the four wheels. When the electric vehicle is traveling at a speed greater than a preset speed, if any one of the four wheels experiences a tire blowout, in response to the sudden change in wheel speed of any one of the four wheels, the electric vehicle controls the drive system to adjust the driving force or controls the braking system to adjust the braking force. The sudden change in wheel speed of any one of the four wheels refers to a situation where, within a preset time period, the increase in wheel speed of the wheel with the sudden change is greater than a first threshold, while the increase in wheel speed of the other three wheels is less than a second threshold, where the first threshold is greater than the second threshold.

[0035] In conjunction with the second aspect, in some implementations of the second aspect, the sudden change in wheel speed of any one of the four wheels also includes the decrease in the driving torque of the wheel whose wheel speed suddenly changes within a preset time period being greater than the third amplitude, and the increase in the driving torque of the wheel whose wheel speed suddenly changes after the preset time period.

[0036] In conjunction with the second aspect, in some implementations of the second aspect, the drive system includes three motors. One of the three motors drives the two front wheels, and each of the other two motors drives one of the two rear wheels. Controlling the drive system to adjust the drive force output specifically includes, when the wheel with the sudden change in wheel speed is a front wheel, first controlling one motor to reduce its torque output, then controlling the motor corresponding to the rear wheel on the opposite side of the wheel with the sudden change in wheel speed to reduce its torque output, and then controlling the motor corresponding to the rear wheel on the same side as the wheel with the sudden change in wheel speed to increase its torque output. When the wheel with the sudden change in wheel speed is a rear wheel, first controlling one motor to reduce its torque output, and then controlling the motor corresponding to the rear wheel on the opposite side of the wheel with the sudden change in wheel speed to reduce its torque output.

[0037] In conjunction with the second aspect, in some implementations of the second aspect, the drive system includes three motors, one of which drives the two front wheels, and each of the other two motors drives one of the two rear wheels. The four wheels include two wheels on the left and two wheels on the right. The control braking system adjusts the braking force, specifically including, when the wheel with the abrupt change in wheel speed is a front wheel, the control braking system outputs braking force to a rear wheel on the opposite side of the wheel with the abrupt change in wheel speed. When the wheel with the abrupt change in wheel speed is a rear wheel, the control braking system outputs braking force to the other rear wheel on the opposite side of the wheel with the abrupt change in wheel speed.

[0038] Thirdly, this application provides a method for tire blowout control in an electric vehicle. The electric vehicle includes four motor controllers and four motors. The four motors drive the four wheels of the electric vehicle, and each of the four motor controllers controls the output torque of one of the four motors. The method includes, during the electric vehicle's operation at a speed exceeding a preset speed, if a tire blowout occurs at any one of the four wheels, in response to the sudden change in wheel speed at any one wheel, the motors corresponding to the other three wheels adjust their torque output. The sudden change in wheel speed at any one wheel refers to an increase in the wheel speed of any one wheel exceeding the increase in the wheel speed of the other three wheels within a preset time period.

[0039] In conjunction with the third aspect, in some implementations of the third aspect, the sudden change in the wheel speed of any one of the four wheels further includes, within a preset time period, the increase in the wheel speed of the wheel with the sudden change being greater than a first threshold, while the increase in the wheel speed of the other three wheels being less than a second threshold, wherein the first threshold is greater than the second threshold.

[0040] In conjunction with the third aspect, in some implementations of the third aspect, the torque output adjustment of the motors corresponding to the other three wheels sequentially includes: the motor coaxial with the motor corresponding to the wheel with the sudden change in wheel speed first reducing its torque output; the motor not coaxial with and on the opposite side of the motor corresponding to the wheel with the sudden change in wheel speed then reducing its torque output; and the motor on the same side of the motor corresponding to the wheel with the sudden change in wheel speed then increasing its torque output. Specifically, the motor corresponding to the wheel with the sudden change in wheel speed and the coaxial motor are used to drive the two front wheels of the electric vehicle or the two rear wheels of the electric vehicle; the motor corresponding to the wheel with the sudden change in wheel speed and the motor on the same side are used to drive the two left wheels of the electric vehicle or the two right wheels of the electric vehicle.

[0041] Specifically, other beneficial effects can be referred to the beneficial effects described in the first aspect, and will not be repeated here. Attached Figure Description

[0042] Figure 1 This is an architectural diagram of the vehicle provided in the embodiments of this application;

[0043] Figure 2 This is another vehicle architecture schematic diagram provided in the embodiments of this application;

[0044] Figure 3 This is a schematic diagram of a vehicle signal connection provided in an embodiment of this application;

[0045] Figure 4 This is a schematic diagram of the tire blowout process provided in an embodiment of this application;

[0046] Figure 5 This is another schematic diagram of a tire blowout process provided in an embodiment of this application;

[0047] Figure 6 This is a schematic diagram of tire blowout control provided in an embodiment of this application;

[0048] Figure 7 This is another schematic diagram of tire blowout control provided in an embodiment of this application;

[0049] Figure 8 This is another schematic diagram of tire blowout control provided in an embodiment of this application;

[0050] Figure 9 This is another schematic diagram of tire blowout control provided in an embodiment of this application;

[0051] Figure 10 This is another schematic diagram of tire blowout control provided in an embodiment of this application;

[0052] Figure 11 This is another schematic diagram of tire blowout control provided in an embodiment of this application;

[0053] Figure 12 This is another schematic diagram of tire blowout control provided in an embodiment of this application;

[0054] Figure 13 This is a schematic diagram of a tire blowout control method provided in an embodiment of this application. Detailed Implementation

[0055] 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.

[0056] High-speed tire blowouts are a major cause of vehicle loss of control and serious traffic accidents. As the only critical component of a car in direct contact with the ground, tires significantly impact a vehicle's power, braking, ride comfort, and handling stability. At high speeds, a tire blowout drastically alters the vehicle's dynamic characteristics, disrupting its balance and causing it to deviate from its original trajectory. In reality, severe high-speed tire blowouts often occur within 0.1 seconds, leaving drivers and vehicles with extremely limited reaction and control time. Therefore, developing rapid and efficient tire blowout detection and control technologies can significantly improve vehicle stability and controllability after a blowout, ensuring driving safety.

[0057] In one possible implementation, a direct detection method based on tire pressure sensors can be used to detect the wheel that has blown out, and control can be implemented through the braking system. Wireless tire pressure sensors monitor the tire pressure of each tire in real time, and based on the tire pressure, determine whether a blowout has occurred for each tire. Wheel speed signals collected by wheel speed sensors are then transmitted to the central control module. Finally, the anti-lock braking system (ABS) / electronic stability program (ESP) is used to control the entire vehicle after the blowout.

[0058] It should be understood that tire pressure sensor-based detection methods, where the tire pressure sensor is installed in the tire, are limited by their own accuracy and energy source, resulting in a low sampling rate, long detection time, and poor real-time performance. Furthermore, tire pressure sensor-based detection methods require wireless signal transmission between different control units, leading to long system links, low reliability, and a tendency for false alarms. Tire pressure detection systems require 1-6 seconds for detection; ABS / ESP systems have long braking response delays; vehicle control based on the braking system can easily cause significant changes in vehicle speed, which is detrimental to maintaining the current driving state and can easily lead to secondary accidents in certain driving scenarios; tire blowout detection relies on tire pressure sensor signals, while blowout control depends on the motor drive system and vehicle braking system, requiring signal transmission and real-time interaction between different modules, resulting in long control signal transmission links and potential system stability issues; controlling only a single wheel's drive or braking force limits the overall vehicle yaw control.

[0059] This application provides a vehicle controller for tire blowout detection, an electric vehicle for tire blowout control, and a method thereof. The vehicle controller can detect tire blowout by combining multiple wheel speeds, thereby improving the tire blowout detection speed, enabling the control system to intervene earlier, reducing control difficulty, and responding to tire blowouts.

[0060] Figure 1 and Figure 2This is a schematic diagram of the architecture of the electric vehicle 10 provided in the embodiments of this application.

[0061] The electric vehicle 10 includes a drive system and a braking system. The drive system provides driving force to the four wheels of the electric vehicle, and the braking system provides braking force to the four wheels.

[0062] In one embodiment, combined with Figure 1 and Figure 2 The drive system includes four powertrains, each powertrain including a motor controller and a motor. The electric vehicle 10 includes four wheels, four motor controllers, four motors, a vehicle controller 60, a brake controller 70, and four brakes.

[0063] like Figure 1 As shown in (a), the electric vehicle 10 can be a wheel-side four-motor drive architecture, with the motors mounted on the sides of the driving wheels and controlled by separate motor controllers. The electric vehicle 10 can be as follows: Figure 1 The centralized four-motor drive architecture shown in (b) has two motors set together to drive either the two front wheels or the two rear wheels.

[0064] The four motor controllers include motor controller 21, motor controller 22, motor controller 23, and motor controller 24. The four motors include motor 31, motor 32, motor 33, and motor 34. Motor controller 21 controls motor 31 to drive wheel 41, motor controller 22 controls motor 32 to drive wheel 42, motor controller 23 controls motor 33 to drive wheel 43, and motor controller 24 controls motor 34 to drive wheel 44.

[0065] 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 share the same axle and are connected via the front axle, while the left and right rear wheels share the same axle and are connected via the rear axle. Based on their location, the left front and left rear wheels are on the same side (left side), while the right front and right rear wheels are on the same side (right side).

[0066] Similarly, of the four motors, the two motors driving the two front wheels are coaxial, and the two motors driving the two front wheels are also coaxial. Of the four motors, the two motors driving the two left wheels are on the same side, and the two motors driving the two right wheels are also on the same side.

[0067] In one embodiment, the electric vehicle 10 may also be as follows: Figure 1 As shown in (c), one motor drives the two front wheels of the electric vehicle 10, and two motors drive the two rear wheels of the electric vehicle 10 respectively.

[0068] In one embodiment, the electric vehicle 10 also includes four wheel speed sensors, each used to detect the rotational speed of one wheel. For example, wheel speed sensor 81 is used to detect the left front wheel 41, wheel speed sensor 82 is used to detect the right front wheel 42, wheel speed sensor 83 is used to detect the left rear wheel 43, and wheel speed sensor 84 is used to detect the right rear wheel 45.

[0069] Figure 3 The signal connections of the vehicle controller 60 of the electric vehicle 10 are shown.

[0070] In one embodiment, the vehicle controller 60 is connected to wheel speed sensors via a signal interface. The wheel speed sensors detect the rotational speeds of the four wheels, and the vehicle controller 60 receives signals from the wheel speed sensors to obtain the rotational speeds of the four wheels. The vehicle controller 60 is also connected to the motor controller and brake controller of the electric vehicle 10, so that after a tire blowout is detected, it can send control signals to the drive system and braking system of the vehicle 10 to control the drive system to adjust the driving force or control the braking system to adjust the braking force.

[0071] Continue reading Figure 2 In one embodiment, the electric vehicle 10 further includes a braking system, which includes a brake controller 70 and four brakes, namely brake 71, brake 72, brake 73, and brake 74. The brake controller 70 is used to control the four brakes to output braking force to the four wheels of the electric vehicle 10 to brake the electric vehicle 10.

[0072] In one embodiment, the vehicle controller 60 is connected to the accelerator pedal. The vehicle controller 60 calculates the overall vehicle torque demand based on the accelerator pedal opening during the driving process of the electric vehicle 10 and sends a torque control signal to each motor controller according to the overall vehicle torque demand. Each motor controller controls the corresponding motor to output torque to drive the corresponding wheel according to the torque control signal.

[0073] In one embodiment, the vehicle controller 60 is connected to the brake pedal. The vehicle controller 60 calculates the braking demand of the entire vehicle based on the brake pedal opening during the driving process of the electric vehicle 10 and sends a braking signal to the brake controller 70 according to the braking demand. The brake controller 70 controls the corresponding brake to brake the corresponding wheel according to the indication of the braking signal.

[0074] If any one of the four wheels of the electric vehicle 10 blows out while it is in motion, the blown wheel will experience a blowout braking effect, causing a sudden increase in wheel speed and a deviation in the direction of travel of the electric vehicle 10. To ensure the safety of the driver and the electric vehicle 10, it is necessary to adjust the direction of travel of the electric vehicle 10. The vehicle controller provided in this application can detect a tire blowout and control the vehicle in response to the blowout. With the coordination of torque or braking force output to the three normal wheels, it can generate lateral torque in the electric vehicle 10, thereby enabling the electric vehicle 10 to be controlled laterally.

[0075] The vehicle controller provided in this application can simultaneously perform tire blowout detection and tire blowout control functions.

[0076] The tire blowout detection function of the vehicle controller 60 provided in this application embodiment will be described in detail below.

[0077] If a tire blows out while the electric vehicle 10 is traveling at a speed greater than a preset speed, the vehicle controller 60 determines that a tire blowout has occurred in response to the sudden change in the wheel speed of any one of the four wheels. Here, a sudden change in the wheel speed of any one of the four wheels refers to an increase in the wheel speed of any one of the four wheels exceeding the increase in the wheel speed of the other three wheels within a preset time period.

[0078] The tire blowout detection function provided in this embodiment only activates when the speed of the electric vehicle 10 exceeds a preset speed. In other words, the vehicle controller 60 only detects and locates the blowout wheel by using the rotational speed of the wheel with the blowout as a criterion when the electric vehicle's speed exceeds the preset speed. This is to avoid misjudgments during acceleration or low-speed driving of the electric vehicle 10, thereby improving the accuracy of tire blowout detection. For example, the preset speed can be 15 km / h or 20 km / h.

[0079] Due to the braking effect of a blowout, the speed of the motor corresponding to the blowout wheel will suddenly increase. Therefore, the vehicle controller 60 can determine whether a blowout has occurred and locate the wheel that has blown out by using the motor speed of the blowout wheel and the motor speeds of other wheels as criteria.

[0080] In one embodiment, a sudden change in the wheel speed of any one of the four wheels specifically includes, within a preset time period, the wheel speed increase of any one of the four wheels being greater than a first amplitude, while the wheel speed increase of the other three wheels being less than a second threshold, wherein the first amplitude is greater than the second amplitude.

[0081] The vehicle controller 60 responds to the following: the vehicle speed of the electric vehicle 10 is greater than a preset speed, the speed increase of any one of the four wheels is greater than a first amplitude within a preset time period, and the speed increase of the other three wheels is less than a second threshold within the preset time period. The vehicle controller 60 then determines that the wheel with the speed increase greater than the first amplitude has blown out.

[0082] Figure 4 A schematic diagram illustrating the wheel speed at which a tire blowout occurs in electric vehicle 10 is provided. Figure 4 As shown, during the time period from 0 to t0, the electric vehicle 10 did not experience a tire blowout, and the rotational speeds of the four wheels of the electric vehicle 10 were basically the same. At time t0, the rotational speed of wheel 42 changed abruptly. During the time period from t0 to t1, the change in rotational speed of wheel 42 was greater than the first amplitude, while the change in rotational speed of the other three wheels besides wheel 42 was less than the second amplitude. This indicates that wheel 42 experienced a tire blowout.

[0083] According to the solution in this application, tire blowout detection and identification are directly performed by utilizing the changing characteristics of multiple wheel rotation speeds; this improves the speed of tire blowout detection, enabling earlier control of tire blowouts and reducing the difficulty of control.

[0084] In one embodiment, a sudden change in the wheel speed of any one of the four wheels also includes a decrease in the driving torque of the wheel whose wheel speed changed within a preset time period being greater than a third amplitude, and an increase in the driving torque of the wheel whose wheel speed changed after the preset time period.

[0085] The vehicle controller 60 responds to the following: the vehicle speed of the electric vehicle 10 is greater than a preset speed; the change in rotational speed of any one of the four wheels is greater than a first amplitude within a preset time period; the change in load torque corresponding to that wheel is greater than a third amplitude within a preset time period and increases after the preset time period; and the change in rotational speed of the other three wheels is less than a second amplitude within the preset time period. The vehicle controller 60 then determines that the wheel with the change in rotational speed greater than the first amplitude has blown out.

[0086] The preset duration can be the sampling time of the resolver sensor, the signal interaction time, or a set period of time as needed. The first and second amplitudes can be set as needed; different amplitude settings can adjust the sensitivity and false alarm rate of the vehicle controller's tire blowout detection.

[0087] The torque output of the motor corresponding to the wheel that experiences a tire blowout will fluctuate significantly in a short period of time, and then stabilize with a noticeable increase in torque value. This characteristic can be used to further determine the cause of the blowout. The vehicle controller 60 can combine wheel speed and load torque as judgment criteria. After determining that a wheel has blown out based on its speed, it can determine the load torque of the motor corresponding to the located blown-out wheel. If the load torque corresponding to that wheel changes significantly in a short period of time and then stabilizes and is greater than the load torque before the significant change, then it can be confirmed that the wheel has blown out.

[0088] Load torque is the actual torque output by the motor, or it can be the actual torque experienced by the corresponding wheel. While motor speed can be measured, load torque is more difficult to measure. Load torque can be observed using a load torque observer. By measuring the motor speed, the load torque can be calculated, thus enabling the observation of the load torque.

[0089] According to the solution in this application, tire blowout detection is performed based on wheel speed and load torque information, avoiding misjudging tire slippage or spinning as a blowout. The blowout detection time is short, the reliability is high, and the misjudgment rate is low.

[0090] Figure 5 A schematic diagram illustrating the load torque change of the wheel in the event of a tire blowout in an electric vehicle 10 is provided. Figure 5 As shown, the change in driving torque corresponding to the wheel whose rotational speed changes abruptly is greater than the third amplitude within a preset time period and increases after the preset time period.

[0091] The following is a detailed description of the specific operation mode of the vehicle controller 60 provided in this application for tire blowout control.

[0092] During the driving process of electric vehicle 10 at a speed less than or equal to a preset speed, vehicle controller 60 outputs torque control signals to four motor controllers according to the accelerator pedal indication, and the four motor controllers control the output torque of the four motors according to the indication of the torque control signals.

[0093] When the speed of electric vehicle 10 is less than or equal to the preset speed, the tire blowout detection function is not triggered, and the vehicle controller 60 will not perform tire blowout detection and control. Therefore, the vehicle controller 60 determines the torque that each motor needs to output based on the accelerator pedal and / or brake pedal to avoid misjudgment when the vehicle starts to accelerate or drives at low speed.

[0094] If a tire blows out during vehicle operation, 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. To ensure the safety of the driver and the vehicle, the vehicle's direction of travel needs to be adjusted. The vehicle controller 60 can detect a tire blowout using the aforementioned method and adjust the torque output to the normal wheels based on the blowout control signal. With the torque output to the three normal wheels working in coordination, lateral torque can be generated in the vehicle, thereby enabling lateral control.

[0095] At this time, the torque control of the vehicle controller will be decoupled from the accelerator pedal. Since the vehicle controller 60 performs torque control according to the tire blowout control algorithm, the torque output by the four motors controlled by the vehicle controller 60 will be different from the torque indicated by the accelerator pedal. Therefore, in one embodiment, the torque output by the four motors indicated by the tire blowout control signal is different from the torque output by the four motors indicated by the accelerator pedal.

[0096] If a tire blows out during the operation of an electric vehicle at a speed greater than the preset speed, the vehicle controller 60 responds to the sudden change in wheel speed of any of the four wheels by controlling the drive system to adjust the driving force or controlling the braking system to adjust the braking force.

[0097] In one embodiment, the vehicle controller 60 controls the drive system to adjust the driving force, specifically by controlling the powertrain on the side of the powertrain corresponding to the wheel with the sudden change in wheel speed to reduce the driving force output; and controlling the powertrain on the same side of the powertrain corresponding to the wheel with the sudden change in wheel speed to increase the driving force output.

[0098] After determining the location of the tire blowout through the tire blowout detection described above, the vehicle controller 60 adjusts the torque output of the four motors to maintain vehicle stability. For example, if the speed change of wheel 42 is greater than the first amplitude within a preset time period and the speed change of other wheels is less than the second amplitude within the preset time period, the vehicle controller 60 determines that wheel 42 has blown out. The vehicle controller 60 then instructs the motor controller to adjust the torque output of the motors to maintain vehicle stability via a tire blowout control signal.

[0099] The following explanation uses the example of motor controller 21 receiving a tire blowout control signal and controlling motor 31. The control process of other motor controllers and motors can be referred to motor controller 21 and motor 31.

[0100] If wheel 41 experiences a tire blowout, the torque output of motors other than motor 31 will be adjusted to maintain vehicle stability. If a tire other than wheel 41 experiences a blowout, motor controller 21 will control motor 31 to adjust its torque output to maintain vehicle stability.

[0101] The vehicle controller 60 sends a tire blowout control signal to the motor controller 21 and three other motor controllers. The tire blowout control signal is used to instruct the four motor controllers to adjust the torque output of the four motors.

[0102] In one embodiment, the four wheels include two wheels on the left and two wheels on the right. The wheel that experiences a tire blowout and the motor 31 are on opposite sides, that is, the wheel that experiences a tire blowout and the wheel driven by the motor 31 are on the left and the right respectively. The tire blowout control signal is used to control the motor 31 to reduce the torque output.

[0103] If the wheel that experiences a tire blowout and the wheel corresponding to motor 31 are on the same side, that is, if the wheel that experiences a tire blowout and the wheel driven by motor 31 are both on the left or both on the right, the tire blowout control signal is used to control motor 31 to increase torque output.

[0104] For example, wheel 41 is the left front wheel. If the right front wheel blows out, the blowout control signal is used to control motor 31 to reduce torque output. If the left rear wheel blows out, the blowout control signal is used to control motor 31 to increase torque output.

[0105] In one embodiment, if the wheel that experiences a tire blowout and the wheel corresponding to a motor are on opposite sides, the tire blowout control signal is used to control the motor 31 to increase the reverse torque output. The direction of the reverse torque is opposite to the rotational speed direction of the motor 31.

[0106] When the wheel that experiences a tire blowout is on a different side from wheel 41, the blowout control signal controls the motor to reduce its positive torque output or controls motor 31 to output negative torque. When the wheel that experiences a tire blowout is on the same side as wheel 41, the blowout control signal controls the motor to increase its positive torque output. The direction of the positive torque is the same as the rotational speed of motor 31, while the direction of the negative torque is opposite to the rotational speed of motor 31. In other words, the positive torque causes the wheel to generate a force that maintains the direction of travel of the electric vehicle 10; the negative torque is the force generated by the wheel that brakes the electric vehicle 10, and is opposite to the direction of travel of the electric vehicle 10.

[0107] like Figure 6 As shown, in Figure 6 In (a), wheel 42 experiences a tire blowout. Wheel 42 and wheel 41 corresponding to motor controller 21 are on opposite sides. At this time, the tire blowout control signal instructs motor 31 to reduce torque output. In addition, the tire blowout control signal controls motor 33 to increase torque output, and the tire blowout control signal controls motor 34 to increase torque output.

[0108] exist Figure 6In (b), wheel 43 experiences a tire blowout. Wheel 43 and the wheel 41 corresponding to motor controller 21 are on the same side. At this time, the tire blowout control signal controls motor 31 to increase torque output. In addition, the tire blowout control signal controls motor 32 to decrease torque output, and the tire blowout control signal controls motor 34 to decrease torque output.

[0109] As mentioned above, the electric vehicle 10 includes two axles, one axle for connecting two front wheels and the other axle for connecting two rear wheels. In response to the two wheels on the same axle as wheel 41 that have experienced a tire blowout, the motor controller 21 controls the motor 31 to adjust the torque output before the two motors corresponding to the other axle adjust the torque output.

[0110] In one embodiment, the two powertrains driving the two front wheels are coaxial, and the two powertrains driving the two rear wheels are also coaxial. Controlling the drive system to adjust the driving force sequentially includes first controlling the powertrain coaxial with the wheel corresponding to the wheel with the sudden change in wheel speed to reduce its driving force output; then controlling the powertrain on a different axle and side from the wheel corresponding to the wheel with the sudden change in wheel speed to reduce its driving force output; and finally controlling the powertrain on the same side as the wheel corresponding to the wheel with the sudden change in wheel speed to increase its driving force output.

[0111] When a tire blows out in electric vehicle 10, different control methods can be used for the normal wheels in different positions. The control priority for wheels in different positions differs. During tire blowout control, vehicle controller 60 prioritizes torque reduction control followed by torque increase control. The motor control priority for the wheel coaxial with the blown wheel but on the opposite side is higher than other motors. Wheels on the opposite side of the blown wheel can undergo torque reduction control, i.e., reducing the positive torque output of the motor or making the motor output negative torque. Wheels on the opposite side of the blown wheel can undergo torque increase control, i.e., increasing the positive torque output of the motor.

[0112] For example, wheel 41 is the left front wheel, wheel 42 is the right front wheel, wheel 43 is the left rear wheel, and wheel 44 is the right rear wheel. If wheel 42 blows out, the vehicle controller 60 first controls motor 31 to reduce torque output, then controls motor 33 to reduce torque output, and finally controls motor 34 to increase torque output.

[0113] Figure 7 This diagram illustrates the tiered adjustments made by the four motor controllers when an electric vehicle 10 experiences a tire blowout. Figure 7As shown, during the operation of the electric vehicle 10, wheel 42 experiences a tire blowout. Wheel 41, corresponding to motor controller 21, is coaxial with wheel 42 but on opposite sides. Therefore, the blowout control signal first instructs motor controller 21 to control motor 31 to reduce torque output. Then, the blowout control signal instructs motor controller 23, corresponding to wheel 43 (which is on opposite sides and not on the same axle as wheel 42), to control motor 33 to reduce torque output. Finally, the blowout control signal instructs motor controller 24, corresponding to wheel 44 (which is on the same side and not on the same axle as wheel 42), to control motor 34 to reduce torque output.

[0114] In one embodiment, the vehicle controller 60 is used to determine the torque output by the motors driving the four wheels respectively based on the status signal of the electric vehicle 10. The status signal of the electric vehicle 10 includes the speed, steering angle, yaw rate and center of gravity sideslip angle of the electric vehicle 10. The torque output by the motors driving the four wheels respectively forms a yaw control torque. The yaw control torque is used to control the driving direction of the electric vehicle 10. The yaw control torque is equal to the deflection torque generated by the tire blowout of the electric vehicle 10. The direction of the yaw control torque is opposite to the direction of the deflection torque generated by the tire blowout of the electric vehicle 10. The deflection torque is less than or equal to a control threshold.

[0115] In one embodiment, the vehicle controller 60 sends a tire blowout control signal to the brake controller 70. The torque indicated by the tire blowout control signal and the torque used to drive other wheels form a yaw control torque. The yaw control torque is used to control the driving direction of the electric vehicle 10. The yaw control torque is equal to the deflection torque generated by the tire blowout of the electric vehicle 10. The direction of the yaw control torque is opposite to the direction of the deflection torque generated by the tire blowout of the electric vehicle 10. The deflection torque is less than or equal to a control threshold.

[0116] It should be understood that during vehicle operation, the amount of torque that a motor can increase or decrease on normal wheels is limited. Therefore, there is an upper limit to the yaw torque that the motor on normal wheels can apply to the vehicle. This upper limit of the yaw torque applied to vehicle 10 is the control threshold. When the calculated yaw control torque required to adjust the vehicle's direction of travel is less than or equal to the control threshold, the motor controller adjusts the output torque to control the tire blowout. When the yaw control torque is equal to the lateral torque generated by the tire blowout, and the direction of the yaw control torque is opposite to the direction of the lateral torque generated by the tire blowout, then the vehicle's direction of travel can be effectively controlled. If the calculated yaw control torque required to adjust the vehicle's direction of travel is greater than the control threshold, then the vehicle controller 60 cannot fully control the vehicle's lateral torque by simply controlling the motor to adjust the output torque.

[0117] The electric vehicle 10 also includes a braking system. When a tire blowout occurs during the operation of the electric vehicle, the vehicle controller 60 sends a tire blowout braking signal. The tire blowout braking signal indicates the braking force output by the braking system to each wheel of the vehicle. The braking force output by the braking system to each wheel of the vehicle forms a yaw braking torque. The yaw braking torque is used to control the direction of the vehicle's travel. The yaw braking torque is equal to the eccentric torque generated by the tire blowout. The direction of the yaw braking torque is opposite to the direction of the eccentric torque generated by the tire blowout. The eccentric torque is greater than the control threshold.

[0118] In one embodiment, the vehicle controller 60 controls the braking system to output braking force to at least one of the two right-side wheels of the electric vehicle 10. When the wheel with a sudden change in wheel speed is the right-side wheel, the braking system is controlled to output braking force to at least one of the two left-side wheels of the electric vehicle 10.

[0119] In one embodiment, the vehicle controller 60 controls the braking system to adjust the braking force. Specifically, when the wheel with the sudden change in wheel speed is the left wheel, the braking system first outputs braking force to the wheel of the electric vehicle that is coaxial with the wheel with the sudden change in wheel speed; then, the braking system outputs braking force to the other right wheel of the electric vehicle. When the wheel with the sudden change in wheel speed is the right wheel, the braking system first outputs braking force to the wheel of the electric vehicle that is coaxial with the wheel with the sudden change in wheel speed; then, the braking system outputs braking force to the other left wheel of the electric vehicle. The wheel coaxial with the wheel with the sudden change in wheel speed and the wheel with the sudden change in wheel speed are used to drive the two front wheels or the two rear wheels of the electric vehicle.

[0120] For example, the four wheels include a first wheel and a second wheel on the same axle, and a third wheel and a fourth wheel on the same axle. The first wheel and the third wheel are located on the same side. When the first wheel experiences a tire blowout, the vehicle controller 60 controls the drive system to reduce the positive torque output to the second wheel when the eccentricity torque is less than or equal to a first limit; controls the drive system to reduce the positive torque output to the second wheel and the fourth wheel when the eccentricity torque is greater than the first limit and less than or equal to a second limit; controls the drive system to output negative torque to the third wheel and reduce the positive torque output to the fourth wheel when the eccentricity torque is greater than the second limit and less than or equal to a third limit; and controls the drive system to output negative torque to the third wheel and reduce the positive torque output to the fourth wheel when the eccentricity torque is greater than the second limit and less than or equal to a third limit. When the torque is greater than the third limit and less than or equal to the fourth limit, the drive system is controlled to output negative torque to the second and fourth wheels; when the bias torque is greater than the fourth limit and less than or equal to the control threshold, the drive system is controlled to output negative torque to the second and fourth wheels and increase the positive torque output to the third wheel; when the bias torque is greater than the control threshold and less than or equal to the fifth limit, the braking system is controlled to output braking force to the second wheel; when the bias torque is greater than the fifth limit, the braking system is controlled to output braking force to the second and fourth wheels; wherein, the direction of positive torque is the same as the direction of wheel rotation, and the direction of negative torque is opposite to the direction of wheel rotation.

[0121] Based on the calculated yaw torque required to adjust the vehicle's direction and the magnitude of the maximum yaw control torque of each motor, control is applied step by step to all drive motors. When the output torque of the drive motors is insufficient to adjust the vehicle's direction, braking is applied through the braking system.

[0122] According to the scheme of this application, the control process is divided into two levels based on the required control quantity: motor drive control and braking system control. The first level improves the overall vehicle control effect through the drive system. The required yaw control torque value is used as a reference quantity, and control signals are gradually applied to all motors according to a certain priority. The second level triggers the braking system to intervene when necessary to ensure the reliability of the control system and the safety of the vehicle.

[0123] The following example, a tire blowout on the left front wheel of a four-motor electric vehicle, illustrates the drive and braking control processes of an electric vehicle:

[0124] A blowout of the left front wheel will cause the front of the vehicle to yaw to the left. The lateral torque generated by the blowout is to the left, so a yaw torque to the right needs to be applied to the electric vehicle 10. Depending on the required yaw torque, the motor output torque can be adjusted step-by-step according to the priority of different wheels. When the required yaw torque is less than or equal to the control threshold, drive control is initiated through the drive system.

[0125] like Figure 8 As shown in (a), the positive torque output by the drive motor driving the right front wheel can be reduced preferentially.

[0126] like Figure 8 As shown in (b), if the positive torque output by the drive motor driving the right front wheel is reduced to near 0, and the yaw control torque requirement is not met, the positive torque output by the drive motor driving the right rear wheel is further reduced.

[0127] like Figure 8 As shown in (c), if the positive torque output by the drive motor driving the right rear wheel decreases to near 0 and the yaw control torque requirement is not met, then the drive motor driving the right front wheel is controlled to output negative torque.

[0128] like Figure 8 As shown in (d), if the negative torque output of the drive motor driving the right front wheel reaches its maximum and still does not meet the yaw control torque requirement, then the drive motor driving the right rear wheel is controlled to output negative torque.

[0129] like Figure 8 As shown in (e), if the negative torque output of the drive motor driving the right front wheel reaches its maximum and still does not meet the yaw control torque requirement, then the positive torque output of the drive motor driving the left rear wheel is increased.

[0130] When the required yaw moment is greater than the control threshold, braking control can be achieved through the braking system.

[0131] like Figure 9 As shown in (a), the braking system preferentially applies braking force to the wheel on the opposite side of the left front wheel that has blown out, namely the right front wheel.

[0132] like Figure 9 As shown in (b), when the braking force of the right front tire is applied to the maximum, but the yaw braking torque requirement is still not met, the braking force is further applied to the right rear tire.

[0133] According to the scheme of this application, the drive / braking system is controlled in a hierarchical manner. The control process is divided into two levels: motor drive control and braking system control, based on the required control quantity. The hierarchical control is adopted. The first level improves the overall vehicle control effect through the electric drive system, and the second level triggers the braking system to intervene when necessary, so as to ensure the reliability of the control system and the safety of the vehicle.

[0134] In another embodiment, the drive system includes three motors. One of the motors drives the two front wheels, and each of the other two motors drives one of the two rear wheels. Controlling the drive system to adjust the drive force output specifically includes, when the wheel with the abrupt change in wheel speed is a front wheel, first controlling one motor to reduce its torque output, then controlling the motor corresponding to the rear wheel on the opposite side of the wheel with the abrupt change to reduce its torque output, and then controlling the motor corresponding to the rear wheel on the same side as the wheel with the abrupt change to increase its torque output. When the wheel with the abrupt change in wheel speed is a rear wheel, first controlling one motor to reduce its torque output, and then controlling the motor corresponding to the rear wheel on the opposite side of the wheel with the abrupt change to reduce its torque output.

[0135] In another embodiment, the drive system includes three motors, one of which drives the two front wheels, and each of the other two motors drives one of the two rear wheels. The four wheels include two wheels on the left and two wheels on the right. The braking system adjusts the braking force, specifically by applying braking force to a rear wheel on the opposite side of the wheel experiencing a sudden change in wheel speed when the wheel with the sudden change in wheel speed is a front wheel. Similarly, when the wheel with the sudden change in wheel speed is a rear wheel, the braking system applies braking force to the other rear wheel on the opposite side of the wheel with the sudden change in wheel speed.

[0136] Three-motor vehicles include those with a single motor on the front axle and dual motors on the rear axle. Since the front axle only has one drive motor powering the left and right wheels, the tire blowout control method differs slightly from that of four-motor vehicles. Certain adjustments need to be made to the method described above for these types of vehicles. The tire blowout control process is largely the same for three-motor and four-motor vehicles; the similarities will not be repeated here. The differences will be described instead.

[0137] Because the front axle wheels are driven by a single drive motor, the output torque cannot be controlled individually during operation.

[0138] The following explanation uses the example of a tire blowout in the left front wheel of a three-motor electric vehicle on its front axle:

[0139] like Figure 10 As shown in (a), a tire blowout on the left front wheel causes the front of the car to yaw to the left. At this time, a yaw control torque needs to be applied to the right. This can be achieved by first reducing the positive torque output of the drive motors on the entire front axle, and at the same time reducing the positive torque output of the drive motors driving the right rear wheel.

[0140] like Figure 10 As shown in (b), if the positive torque output by the drive motor driving the right rear wheel decreases to near 0 and the yaw control torque requirement is not met, then the drive motor driving the right rear wheel is controlled to output negative torque.

[0141] like Figure 10 As shown in (c), if the negative torque output of the drive motor driving the right front wheel reaches its maximum and still does not meet the yaw control torque requirement, then the positive torque output of the drive motor driving the left rear wheel is increased.

[0142] The following explanation uses the example of a three-motor electric vehicle experiencing a tire blowout in the left rear wheel of the front axle as an illustration:

[0143] like Figure 11 As shown in (a), a tire blowout on the left rear wheel causes the front of the car to yaw to the left. At this time, a yaw control torque needs to be applied to the right. First, reduce the positive torque output of the drive motor of the entire front axle, and at the same time reduce the positive torque output of the drive motor that drives the right rear wheel.

[0144] like Figure 11 As shown in (b), if the positive torque output by the drive motor driving the right rear wheel decreases to near 0 and the yaw control torque requirement is not met, then the drive motor driving the right rear wheel is controlled to output negative torque.

[0145] The following example illustrates the braking control of a three-motor electric vehicle 10 when its left front and left rear tires burst:

[0146] like Figure 12 As shown in (a), a tire blowout on the left front wheel causes the front of the vehicle to yaw to the left. At this time, the positive torque output of the drive motor on the front axle is reduced, and the braking system needs to apply braking force to the right rear wheel of the vehicle to give the vehicle a yaw control torque to the right.

[0147] like Figure 12As shown in (b), the left rear tire of the vehicle blows out. At this time, the positive torque output of the drive motor of the front axle is reduced. Similarly, the braking system needs to apply braking force to the right rear wheel of the vehicle to give the vehicle a yaw control torque to the right.

[0148] According to the scheme of this application, the drive / braking system is controlled in a hierarchical manner. The control process is divided into two levels: motor drive control and braking system control, based on the required control quantity. The hierarchical control is adopted. The first level improves the overall vehicle control effect through the electric drive system, and the second level triggers the braking system to intervene when necessary, so as to ensure the reliability of the control system and the safety of the vehicle.

[0149] This application provides a method for controlling tire blowout. The method includes:

[0150] When the electric vehicle 10 is traveling at a speed less than or equal to a preset speed, the four motors are controlled to output torque according to the torque signal indication.

[0151] If a tire blows out while the electric vehicle 10 is traveling at a speed exceeding a preset speed, the motors corresponding to the other three wheels will adjust their torque output in response to the sudden change in wheel speed of the one wheel. Here, a sudden change in wheel speed refers to an increase in the wheel speed of the one wheel exceeding the increase in the wheel speed of the other three wheels within a preset time period.

[0152] The vehicle tire blowout control method provided in this application embodiment sets a preset vehicle speed, i.e., a lower limit V for tire blowout detection speed. min When the vehicle speed exceeds the limit, the tire blowout detection function is enabled to avoid misjudgment when the electric vehicle starts accelerating or is driving at low speed.

[0153] After a tire blows out in electric vehicle 10, a "blowout braking effect" occurs, causing a sudden step increase in wheel speed. Utilizing this change characteristic, the ratio of the blowout wheel speed to the speed of other normal tires can be used as a key indicator for judging a blowout.

[0154] In one embodiment, the sudden change in wheel speed of any one of the four wheels further includes, within a preset time period, the increase in wheel speed of the wheel with the sudden change in wheel speed being greater than a first threshold, while the increase in wheel speed of the other three wheels being less than a second threshold, wherein the first threshold is greater than the second threshold.

[0155] In one embodiment, the torque output adjustment of the motors corresponding to the other three wheels sequentially includes: the motor coaxial with the motor corresponding to the wheel with the sudden change in wheel speed first reducing its torque output; the motor on the opposite side and not coaxial with the motor corresponding to the wheel with the sudden change in wheel speed then further reducing its torque output; and the motor on the same side as the motor corresponding to the wheel with the sudden change in wheel speed then increasing its torque output. The motor corresponding to the wheel with the sudden change in wheel speed and the coaxial motor are used to drive the two front wheels or the two rear wheels of the electric vehicle; the motor corresponding to the wheel with the sudden change in wheel speed and the motor on the same side are used to drive the two left wheels or the two right wheels of the electric vehicle.

[0156] Except for the motor on the wheel side where the tire bursts, the other three motors are used according to the required yaw control torque ΔM. z The size is controlled step by step based on ΔM. z The direction determines the torque change pattern (increasing or decreasing torque) of the left and right motors. The maximum torque change of each motor under the current pattern is determined, and the maximum yaw control torque achievable by each motor is calculated. During tire blowout control, the control priority of the three motors is: decreasing torque control > increasing torque control, with the motor on the opposite side of the blown tire on the same axle having a higher priority than other motors. In actual control, based on ΔM... z The maximum yaw control torque of each motor is controlled step by step, and control signals are gradually applied to all motors.

[0157] Figure 13 Apart from the flowchart illustrating the vehicle tire blowout control method provided in the embodiments of this application, the specific details of the vehicle tire blowout control method provided in the embodiments of this application are as described above, and will not be repeated here.

[0158] In this embodiment, after a tire blowout occurs, the electric vehicle 10 adopts a tiered control strategy to improve the safety of tire blowout control. Specifically, the vehicle controller 60 calculates the yaw control torque ΔM required for the current control using signals such as the electric vehicle 10's speed, front wheel steering angle, yaw rate, and sideslip angle input from the electric vehicle 10's sensors. z and the set control threshold ΔM c Compare ΔM c Related to the motor's torque output capability, it is generally greater than or equal to the upper limit of the yaw moment that a motor on the normal tire side can apply. If ΔM z <ΔM c If the condition is met, a tire blowout control signal is output, and the four motors are used to control the tire blowout and distribute the drive control torque; otherwise, a tire blowout braking signal is directly output to activate the braking system for differential braking control.

[0159] According to the scheme of this application, the drive / braking system is controlled in a hierarchical manner. The control process is divided into two levels: motor drive control and braking system control, based on the required control quantity. The hierarchical control is adopted. The first level improves the overall vehicle control effect through the electric drive system, and the second level triggers the braking system to intervene when necessary, so as to ensure the reliability of the control system and the safety of the electric vehicle 10.

[0160] In the embodiments of this application, the words "exemplary," "for example," etc., are used to indicate that they are examples, illustrations, or descriptions. Any embodiment or design that is described as "exemplary" in this application should not be construed as being more preferred or advantageous than other embodiments or design options. Specifically, the use of the term "exemplary" is intended to present the concept in a concrete manner.

[0161] It should be understood that the term "embodiment" used throughout this specification means that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, various embodiments throughout this specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments.

[0162] It should also be understood that in this application, "when," "if," "in the circumstances of," and "if" all refer to a situation where a corresponding action will be taken under certain objective circumstances, and are not time-limited. They do not require the device to perform a judgment action, nor do they imply any other limitations. Furthermore, in this application, the descriptions of conditions such as "when," "if," "in the circumstances of," and "if" can be understood as necessary conditions, without limiting whether the condition is a sufficient condition or a necessary and sufficient condition. For example, "in the case of A, execute B" can be understood as "if at least A is satisfied, execute B."

[0163] Furthermore, in the various embodiments of this application, "B corresponding to A" means that B is associated with A, and B can be determined based on A. However, it should also be understood that determining B based on A does not mean that B is determined solely based on A; B can also be determined based on A and / or other information.

[0164] "At least one" refers to one or more, while "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, "at least one of A, B, or C" includes A, B, C, AB, AC, BC, or ABC; "at least one of A, B, and C" can also be understood as including A, B, C, AB, AC, BC, or ABC. Furthermore, unless otherwise specified, the ordinal numbers such as "first" and "second" mentioned in the embodiments of this application are used to distinguish multiple objects and are not used to limit the order, sequence, priority, or importance of multiple objects.

[0165] 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 vehicle controller for tire blowout detection, characterized in that, The vehicle controller is applied to an electric vehicle, which includes a drive system and a braking system. The drive system provides driving force to the four wheels of the electric vehicle, and the braking system provides braking force to the four wheels. The vehicle controller is used for: If, during the operation of the electric vehicle at a speed greater than a preset speed, any one of the four wheels experiences a tire blowout and the wheel speed changes abruptly, and the yaw moment of the electric vehicle is less than or equal to a control threshold after any one wheel blows out, the drive system is controlled to reduce the driving force of the wheel on the same side as the wheel that blows out and to increase the driving force of the wheel on the same side as the wheel that blows out. When any wheel blows out, the yaw moment of the electric vehicle exceeds the control threshold, the drive system is controlled to adjust the driving force and the braking system is controlled to adjust the braking force. Wherein, the sudden change in wheel speed of any one wheel means that within a preset time period, the wheel speed increase of the wheel that has blown out is greater than a first amplitude, the wheel speed increase of the other three wheels is less than a second amplitude, and the driving torque of the wheel with the sudden change in wheel speed decreases within the preset time period and increases after the preset time period, with the first amplitude being greater than the second amplitude.

2. The vehicle controller according to claim 1, characterized in that, The vehicle controller is used for: The braking system is controlled to output braking force to at least one of the two wheels opposite the wheel that has blown out.

3. The vehicle controller according to claim 2, characterized in that, The four wheels include two wheels on the left and two wheels on the right, and the vehicle controller is specifically used for: When the wheel that blows out is the left wheel, the braking system is controlled to output braking force to at least one of the two right wheels of the electric vehicle. When the tire blows out on the right-hand wheel, the braking system is controlled to output braking force to at least one of the two wheels on the left side of the electric vehicle.

4. The vehicle controller according to claim 2, characterized in that, The vehicle controller is specifically used for: First, control the braking system to output braking force to the wheel on the same axle as the wheel with the blown tire, and then control the braking system to output braking force to the wheel diagonally opposite any of the blown tires.

5. The vehicle controller according to claim 4, characterized in that, The vehicle controller is specifically used for: When the wheel that blows out is the left wheel, first control the braking system to output braking force to the wheel of the electric vehicle that is on the same axle as the wheel whose wheel speed suddenly changed, and then control the braking system to output braking force to the other right wheel of the electric vehicle. When the tire blowout occurs on the right-hand wheel, the braking system is first controlled to output braking force to the wheel of the electric vehicle that is on the same axle as the wheel whose wheel speed suddenly changed, and then the braking system is controlled to output braking force to the other left-hand wheel of the electric vehicle; wherein, The wheel coaxial with the wheel that experienced the tire blowout and the wheel whose wheel speed suddenly changed are used to drive the two front wheels or the two rear wheels of the electric vehicle.

6. The vehicle controller according to any one of claims 1-5, characterized in that, The vehicle controller is specifically used for: The drive system is controlled to increase the driving force output to the wheel on the same side as the wheel that experienced the tire blowout.

7. The vehicle controller according to any one of claims 1-5, characterized in that, The vehicle controller is specifically used for: The drive system is controlled to reduce the driving force output to the wheels on the different sides of the wheel that has blown out.

8. The vehicle controller according to claim 1, characterized in that, The two powertrains used to drive the two front wheels are two powertrains on the same axis, and the two powertrains used to drive the two rear wheels are two powertrains on the same axis. The process of controlling the drive system to adjust the drive force includes, in sequence: First, control the powertrain coaxial with the wheel that experienced the tire blowout to reduce the driving force output; Then control the powertrain on the different axle and side of the powertrain corresponding to the wheel that suffered the tire blowout to reduce the driving force output; Then, control the powertrain on the same side as the wheel that experienced the tire blowout to increase the driving force output.

9. The vehicle controller according to claim 8, characterized in that, Each powertrain includes a motor controller and a motor, wherein the motor controller controls the output torque of the motor to drive a wheel; The vehicle controller is used to send a torque signal to the motor controller of each powertrain, the torque signal being used to instruct the motor controller to control the motor to output the torque indicated by the torque signal.

10. An electric vehicle with tire blowout control, characterized in that, The electric vehicle includes a drive system and a braking system. The drive system provides driving force to the four wheels of the electric vehicle, and the braking system provides braking force to the four wheels. The electric vehicle is used for: If, during the operation of the electric vehicle at a speed greater than a preset speed, any one of the four wheels experiences a tire blowout and the wheel speed changes abruptly, and the yaw moment of the electric vehicle is less than or equal to a control threshold after any one wheel blows out, the drive system is controlled to reduce the driving force of the wheel on the same side as the wheel that blows out and to increase the driving force of the wheel on the same side as the wheel that blows out. When any wheel blows out, the yaw moment of the electric vehicle exceeds the control threshold, the drive system is controlled to adjust the driving force and the braking system is controlled to adjust the braking force. Wherein, a sudden change in wheel speed of any one of the four wheels means that within a preset time period, the increase in wheel speed of the wheel with the sudden change in wheel speed is greater than a first amplitude, the increase in wheel speed of the other three wheels is less than a second amplitude, and the driving torque of the wheel with the sudden change in wheel speed decreases within the preset time period and increases after the preset time period, with the first amplitude being greater than the second amplitude.

11. The electric vehicle according to claim 10, characterized in that, The electric vehicle is used for: The braking system is controlled to output braking force to at least one of the two wheels opposite the wheel that has blown out.

12. The electric vehicle according to claim 11, characterized in that, The four wheels include two wheels on the left and two wheels on the right, and the electric vehicle is specifically used for: When the wheel that blows out is the left wheel, the braking system is controlled to output braking force to at least one of the two right wheels of the electric vehicle. When the tire blows out on the right-hand wheel, the braking system is controlled to output braking force to at least one of the two wheels on the left side of the electric vehicle.

13. The electric vehicle according to any one of claims 10-12, characterized in that, The electric vehicle is specifically used for: First, control the braking system to output braking force to the wheel on the same axle as the wheel with the blown tire, and then control the braking system to output braking force to the wheel diagonally opposite any of the blown tires.

14. The electric vehicle according to claim 10, characterized in that, The drive system includes three motors, one of which drives the two front wheels, and each of the other two motors drives one of the two rear wheels. The control of the drive system to adjust the drive force output specifically includes: When the tire blowout occurs on a front wheel, first control the motor to reduce torque output, then control the motor corresponding to the rear wheel on the opposite side of the wheel whose wheel speed changed abruptly to reduce torque output, and then control the motor corresponding to the rear wheel on the same side of the wheel whose speed changed abruptly to increase torque output. When the tire blowout occurs on a rear wheel, first control one motor to reduce torque output, then control the motor corresponding to the rear wheel on the opposite side of the wheel whose wheel speed changed abruptly to reduce torque output.

15. The electric vehicle according to claim 10, characterized in that, The drive system includes three motors, one of which drives the two front wheels, and each of the other two motors drives one of the two rear wheels; the four wheels include two wheels on the left and two wheels on the right. Controlling the braking system to adjust the braking force specifically includes: When the wheel whose wheel speed changes abruptly is a front wheel, the braking system is controlled to output braking force to a rear wheel on the opposite side of the wheel whose wheel speed changes abruptly. When the wheel whose wheel speed suddenly changes is a rear wheel, the braking system is controlled to output braking force to another rear wheel on a different side from the wheel whose wheel speed suddenly changes.

16. A method for controlling tire blowout in an electric vehicle, characterized in that, The electric vehicle includes four motor controllers and four motors, each of which drives one of the four wheels of the electric vehicle. Each of the four motor controllers controls the output torque of one of the four motors. The method includes: If, during the operation of the electric vehicle at a speed exceeding a preset speed, any one of the four wheels experiences a tire blowout, resulting in a sudden change in wheel speed, When any wheel blows out, the yaw moment of the electric vehicle is less than or equal to the control threshold. The motors corresponding to the other three wheels reduce the driving force of the wheel on the side opposite to the wheel that has blown out and increase the driving force of the wheel on the same side as the wheel that has blown out. When any wheel experiences a tire blowout, the yaw moment of the electric vehicle exceeds the control threshold. The drive system is then controlled to reduce the driving force of the wheel on the opposite side of the blowout wheel and increase the driving force of the wheel on the same side as the blowout wheel. The braking system is also controlled to adjust the braking force. Specifically, a sudden change in wheel speed for any of the four wheels refers to a situation where, within a preset time period, the increase in wheel speed of the wheel with the sudden change is greater than a first amplitude, the increase in wheel speed of the other three wheels is less than a second amplitude, and the driving torque of the wheel with the sudden change in wheel speed decreases within the preset time period and increases after the preset time period. The first amplitude is greater than the second amplitude.

17. The method according to claim 16, characterized in that, The torque output adjustment of the motors corresponding to the other three wheels includes, in order: The motor coaxial with the motor corresponding to the wheel whose wheel speed suddenly changes reduces its torque output first. The motors on different shafts and sides of the motors corresponding to the wheels with sudden speed changes further reduce their torque output; The motor on the same side as the motor corresponding to the wheel whose wheel speed suddenly changes increases its torque output; The motor corresponding to the wheel with the sudden change in wheel speed and the coaxial motor are used to drive the two front wheels of the electric vehicle or the two rear wheels of the electric vehicle. The motor corresponding to the wheel with the sudden change in wheel speed and the motor on the same side are used to drive the two left wheels of the electric vehicle or the two right wheels of the electric vehicle.

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