Electric vehicle and method for tire burst detection control

Abstract

The application provides a kind of electric vehicle and method of tire burst detection control, it is related to new energy vehicle field, can be applied to electric car or hybrid vehicle.In the driving process of the vehicle speed of electric vehicle is greater than the preset vehicle speed, in response to the tire burst of any one of the four wheels, each motor controller is used to send tire burst signal to central controller, and the tire burst signal is used to indicate the wheel position of tire burst.In response to the same wheel position indicated by the four tire burst signals sent by the four motor controllers, the central controller is used to send tire burst control signal to each motor controller, and the tire burst control signal is used to indicate that each motor controller controls the torque output of the corresponding motor.Adjust according to the scheme, use motor speed information, combine the judgment results of multiple motor controllers in the central controller, realize rapid tire burst detection, improve the redundancy of detection system, speed up the detection and positioning speed, improve the reliability and safety of vehicle.

Description

Technical Field

[0001] This application relates to the field of new energy vehicles, and more specifically, to an electric vehicle and method for tire blowout detection and control. 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 approach has long detection times, poor real-time performance, untimely control intervention, and poor stability.

[0004] Therefore, how to quickly detect and control tire blowouts and improve vehicle safety is an urgent problem to be solved. Summary of the Invention

[0005] This application provides an electric vehicle and method for tire blowout detection and control. By comprehensively judging the motor speed and combining the judgment results of multiple motor controllers in the central controller, the system can quickly identify tire blowout faults and locate the faulty wheel, thereby improving the redundancy of the tire blowout detection system, accelerating the detection and location speed, and enhancing the reliability of detection and the safety of the vehicle.

[0006] In a first aspect, this application provides an electric vehicle for tire blowout detection and control, the electric vehicle including a central controller, four motor controllers and four motors, the four motor controllers being used to control the four motors to drive the four wheels of the electric vehicle.

[0007] When the electric vehicle is traveling at a speed greater than the preset speed, in response to a tire blowout at any of the four wheels, each motor controller sends a blowout signal to the central controller, which indicates the position of the wheel that has blown out.

[0008] In response to the four tire blowout signals sent by the four motor controllers indicating the same wheel position, the central controller sends a tire blowout control signal to each motor controller, which instructs each motor controller to adjust the torque output of the corresponding motor.

[0009] The electric 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.

[0010] When a tire blows out on one of the vehicle's wheels, the corresponding motor's speed suddenly increases. This change in speed allows the system to detect the blowout among the four wheels and send a blowout signal to indicate the detection result. This blowout signal can then be sent to the vehicle's central controller or other motor controllers.

[0011] After receiving tire blowout signals from the four motor controllers, the central controller can combine the positions of the wheels that have blown out as indicated by the four blowout signals to make a comprehensive judgment. If the positions of the wheels that have blown out as indicated by the four blowout signals are consistent, it means that the judgment is likely accurate and the wheel can be considered to have blown out.

[0012] The motor controller will only perform tire blowout detection and control when the vehicle speed exceeds the preset speed, to avoid misjudgment when the vehicle starts to accelerate or is driving at low speed.

[0013] According to the solution in this application, the communication latency between motor controllers is low. Multiple motor controllers are used independently for tire blowout detection and tire blowout wheel positioning, improving the redundancy of the tire blowout detection system. By utilizing the speed variation characteristics of distributed motors for wheel blowout detection and identification, and based on speed variation characteristics for blowout detection, the blowout detection time is shortened, allowing for timely intervention and control, reducing the false alarm rate and control difficulty, and improving vehicle safety.

[0014] In conjunction with the first aspect, in some implementations of the first aspect, the central controller, responding to the different wheels indicated by the four tire blowout signals sent by the four motor controllers, outputs torque control signals to the four motor controllers based on the indication of the accelerator pedal. The four motor controllers control the output torque of the four motors according to the indication of the torque control signals.

[0015] After receiving tire blowout signals from the four motor controllers, which have each made their own assessments, the central controller can make a comprehensive judgment based on the location of the blowout wheel indicated by each of the four signals. If the locations of the blowout wheel indicated by the four signals are inconsistent, it indicates a possible misjudgment, and no further blowout control will be implemented. At this point, the central controller determines the required torque output for each motor based on the accelerator pedal and / or brake pedal, and sends a torque control signal to instruct each motor controller to control the output torque of each motor.

[0016] According to the solution in this application, multiple motor controllers are used to perform tire blowout detection and tire blowout wheel positioning independently, which improves the redundancy of the tire blowout detection system and reduces the false judgment rate.

[0017] In conjunction with the first aspect, in some implementations of the first aspect, 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.

[0018] When the central controller detects a tire blowout, it will initiate blowout control. At this time, the torque control of the central controller will be decoupled from the accelerator pedal. The central controller will not determine the torque required for each motor based on the accelerator and / or brake pedals, but will adjust the torque required for each motor based on the blowout control algorithm to control the vehicle's yaw. Therefore, the torque value indicated by the blowout control signal is not determined by the accelerator and / or brake pedals.

[0019] In conjunction with the first aspect, in some implementations of the first aspect, during the driving process of the electric vehicle at a speed less than or equal to a preset speed, the central controller is used to output torque control signals to the four motor controllers according to the indication of the accelerator pedal, and the four motor controllers control the output torque of the four motors according to the indication of the torque control signals.

[0020] The central controller and motor controller will not perform tire blowout detection when the vehicle speed is less than or equal to the preset speed. Instead, they will determine 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 travels at low speed.

[0021] In conjunction with the first aspect, in certain implementations of the first aspect, during the operation of the electric vehicle at a speed exceeding a preset speed, in response to a sudden change in the rotational speed of any one of the four motors, each motor controller outputs a tire blowout signal. This tire blowout signal indicates that the wheel corresponding to the motor with the sudden change in rotational speed has experienced a blowout. Here, a sudden change in the rotational speed of any one of the four motors refers to an increase in the rotational speed of any one of the four motors exceeding the increase in the rotational speed of the other three motors within a preset time period.

[0022] When a tire blows out, the motor speed of the wheel that blows out will suddenly increase due to the braking effect of the blowout. Therefore, the motor controller can determine whether a tire blowout has occurred and locate the wheel that has blown out by using the motor speed of the blown-out wheel and the motor speed of other wheels as the criteria.

[0023] The wheel corresponding to the motor can be understood as the wheel being driven by the motor. Similar expressions in this application can be understood in this way, and will not be repeated hereafter.

[0024] 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 motor controllers, or a set period of time as needed. A short preset duration is preferable; if the motor speed increases rapidly while the speeds of other motors remain relatively constant, a tire blowout may occur.

[0025] According to the solution in this application, the difference in the speed of multiple motors is considered to make a judgment, which improves the reliability of the detection results and reduces the false judgment rate. The motor controller performs tire blowout detection based on the motor speed detected by the resolver sensor. The sampling rate is high and the communication latency between motor controllers is low, which shortens the tire blowout detection time.

[0026] In conjunction with the first aspect, in some implementations of the first aspect, the sudden change in the speed of any one of the four motors further includes, within a preset time period, the speed increase of the motor whose speed changes is greater than the first amplitude, and the speed increase of the other three motors is less than the second amplitude, wherein the first amplitude is greater than the second amplitude.

[0027] The first and second amplitude values ​​can be set as needed. Different amplitude settings can adjust the sensitivity and false alarm rate of the motor controller's tire blowout detection.

[0028] In conjunction with the first aspect, in some implementations of the first aspect, the sudden change in the rotational speed of any one of the four motors further includes the change in the output torque of the motor whose rotational speed changes being greater than the third amplitude within a preset time period and increasing after the preset time period.

[0029] The torque of a tire that has blown out will experience a significant, step-like fluctuation within a short period, followed by a substantial increase in torque value after stabilization. This characteristic can be used to further assess tire blowout detection. The motor controller can combine motor speed and the output torque of the drive motor as judgment criteria. After a tire blowout is detected based on speed, the output torque of the motor corresponding to that wheel can be assessed. If the output torque of the motor corresponding to that wheel changes significantly within a short period and then stabilizes, exceeding the output torque before the significant change, then a tire blowout can be confirmed. While motor speed can be measured, output torque is more difficult to measure. Output torque can be observed using a load monitoring device. By measuring the motor speed, the output torque can be calculated, thus enabling the observation of the output torque.

[0030] According to the solution in this application, tire blowout detection is performed based on motor speed and output torque, avoiding misjudging tire slippage or free spin as a tire blowout. The tire blowout detection time is short, the reliability is high, and the misjudgment rate is low.

[0031] In conjunction with the first aspect, in certain implementations of the first aspect, the central controller sends a first tire blowout control signal to a motor controller corresponding to the wheel on the same axle as the wheel that experienced the blowout, a second tire blowout control signal to a motor controller corresponding to the diagonally opposite wheel of the wheel that experienced the blowout, and a third tire blowout control signal to a motor controller corresponding to the wheel on the same side of the wheel that experienced the blowout. The first tire blowout control signal instructs the motor corresponding to the wheel on the same axle of the wheel that experienced the blowout to reduce torque output. The second tire blowout control signal instructs the motor corresponding to the diagonally opposite wheel of the wheel that experienced the blowout to reduce torque output. The third tire blowout control signal instructs the motor corresponding to the wheel on the same side of the wheel that experienced the blowout to increase torque output. The two left wheels or the two right wheels of the electric vehicle are on the same side; the two front wheels or the two rear wheels of the electric vehicle are on the same axle; the left front wheel and the right rear wheel of the electric vehicle are diagonally opposite wheels; or the right front wheel and the left rear wheel of the electric vehicle are diagonally opposite wheels.

[0032] 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. When the wheel corresponding to the motor with a sudden change in speed and the wheel corresponding to the motor are on opposite sides, the tire blowout control signal is used to instruct the control of one motor to increase the reverse torque output; wherein, the direction of the reverse torque is opposite to the direction of the motor's rotational speed.

[0033] The four wheels consist of two wheels on the left and two wheels on the right. The motor controller is used to control the motor to reduce positive torque output or output negative torque when the wheel that experienced a tire blowout is on a different side from another wheel. When the wheel that experienced a blowout is on the same side as another wheel, the motor controller controls the motor to increase positive torque output. The direction of positive torque is the same as the direction of motor rotation speed, while the direction of negative torque is opposite to the direction of motor rotation speed.

[0034] An electric motor consists of a stator winding and a rotor. The motor controller controls the motor's output torque by outputting alternating current to the three-phase stator windings. By adjusting the magnitude and phase of the stator winding current, the motor controller can change the strength and direction of the stator magnetic field, thereby altering the interaction force between the stator and rotor, i.e., the motor torque. Changing the phase of the three-phase current output to the motor causes the rotor to cut the magnetic field generated by the stator windings, converting the rotor's kinetic energy into electrical energy that is input into the power battery; in this case, the motor outputs negative torque. Changing the magnitude of the three-phase current output to the motor increases or decreases the motor's output positive or negative torque.

[0035] According to the scheme of this application, a step-by-step control strategy is adopted, and the motor is controlled step by step according to a certain priority. Through precise and efficient control of the motor drive system, the vehicle body posture can be quickly and effectively adjusted, thereby improving vehicle safety.

[0036] In conjunction with the first aspect, in some implementations of the first aspect, the motor corresponding to the wheel on the same axle as the wheel that experienced the tire blowout first reduces its torque output. The motor corresponding to the diagonally opposite wheel of the wheel that experienced the tire blowout then reduces its torque output. Finally, the motor corresponding to the wheel on the same side of the wheel that experienced the tire blowout increases its torque output.

[0037] 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 control priority for wheels in different positions differs. During blowout control, torque reduction control is prioritized, followed by torque increase control. Wheels on the same axle as the blown wheel but on the opposite side have higher control priority than other motors. Wheels on the opposite side of the blown wheel can be subject to 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 be subject to torque increase control, i.e., increasing the positive torque output of the motor.

[0038] In conjunction with the first aspect, in some implementations of the first aspect, the electric vehicle includes four resolver sensors, each used to detect the rotational speed of one of the four motors. Each of the four motor controllers receives a rotational speed signal from one of the four resolver sensors, and this rotational speed signal indicates the rotational speed of one of the four motors. A sudden change in the rotational speed of any of the other three motors refers to an increase in the rotational speed indicated by the corresponding resolver sensor of any of the other three motors exceeding the increase in the rotational speed indicated by the corresponding resolver sensor of any of the other three motors within a preset time period.

[0039] The motor controller receives detection signals from the resolver sensor and speed signals from other motor controllers in the vehicle via a signal interface. The resolver sensor detects the motor speed, the detection signal indicates the motor speed, and the speed signals indicate the speeds of other motors in the vehicle. The motor controller can detect the wheel that has blown out among the four wheels based on the speed of the motor and the speeds of other motors.

[0040] The resolver sensor is responsible for monitoring and extracting the motor speed, featuring a high sampling rate, and sends the sampled motor speed to the motor controller. Multiple motor controllers in the vehicle can be connected via a CAN bus, LIN bus, or hardwired connection, exchanging signals through these connections. Each motor controller can obtain the motor speed from the resolver sensor of its corresponding motor. This controller can also receive speed signals from other motor controllers via the CAN bus, LIN bus, or hardwired connection, thus enabling it to obtain the speeds of all motors in the vehicle.

[0041] According to the solution in this application, the difference in the speed of multiple motors is considered for judgment, which improves the reliability of the detection results and reduces the false judgment rate. The motor controller performs tire blowout detection based on the motor speed detected by the resolver sensor. The sampling rate is high and the communication delay between motor controllers is low, which shortens the tire blowout detection time. At the same time, both tire blowout detection and tire blowout control can be completed in the motor, resulting in higher stability of the control system, timely intervention control, reduced control torque value required to achieve vehicle attitude and trajectory control, reduced control difficulty, and improved vehicle safety.

[0042] Secondly, this application provides a tire blowout detection method for an electric vehicle. The electric vehicle includes four motor controllers and four motors, each controlling one of the four motors to drive one of the four wheels of the electric vehicle. The method includes, during operation at a speed exceeding a preset speed, in response to a tire blowout at any one of the four wheels, each motor controller outputs a tire blowout signal indicating the position of the blowout wheel. In response to the four tire blowout signals from the four motor controllers indicating the same wheel position, a tire blowout control signal is sent to each motor controller, instructing each motor controller to adjust the torque output of its corresponding motor.

[0043] In conjunction with the second aspect, in some implementations of the second aspect, each motor controller is used to send a tire blowout signal based on the speed changes of the four motors. Specifically, this includes responding to a sudden change in the speed of any one of the four motors by outputting a tire blowout signal. The tire blowout signal is used to indicate that the wheel corresponding to the motor with the sudden speed change has blown out. Here, a sudden change in the speed of any one of the four motors means that within a preset time period, the increase in the speed of any one of the four motors is greater than the increase in the speed of the other three motors.

[0044] In conjunction with the second aspect, in some implementations of the second aspect, the sudden change in the speed of any one of the four motors further includes, within a preset time period, the speed increase of the motor whose speed changes is greater than the first amplitude, and the speed increase of the other three motors is less than the second amplitude, wherein the first amplitude is greater than the second amplitude.

[0045] In conjunction with the second aspect, in some implementations of the second aspect, the sudden change in the rotational speed of any one of the four motors further includes the decrease in the output torque of the motor whose rotational speed changes within a preset time period being greater than the third amplitude and increasing after the preset time period.

[0046] In conjunction with the second aspect, in some implementations of the second aspect, sending a tire blowout control signal to each motor controller includes sending a first tire blowout control signal to a motor controller corresponding to the same axle of the wheel where the blowout occurred, sending a second tire blowout control signal to a motor controller corresponding to the diagonal wheel of the wheel where the blowout occurred, and sending a third tire blowout control signal to a motor controller corresponding to the same side of the wheel where the blowout occurred. The first tire blowout control signal is used to instruct the motor corresponding to the same axle of the wheel where the blowout occurred to reduce torque output. The second tire blowout control signal is used to instruct the motor corresponding to the diagonal wheel of the wheel where the blowout occurred to reduce torque output. The third tire blowout control signal is used to instruct the motor corresponding to the wheel on the same side of the wheel where the blowout occurred to increase torque output. The two left wheels of the electric vehicle are on the same side, or the two right wheels of the electric vehicle are on the same side; the two front wheels of the electric vehicle are on the same axle, or the two rear wheels of the electric vehicle are on the same axle; the left front wheel and right rear wheel of the electric vehicle are diagonal wheels, or the right front wheel and left rear wheel of the electric vehicle are diagonal wheels.

[0047] Thirdly, this application provides a motor controller for a vehicle. The motor controller controls the output torque of one of a plurality of motors in the vehicle, and one motor drives one of the four wheels of the vehicle. During vehicle operation, the motor controller detects a blowout at one of the four wheels based on the rotational speeds of the plurality of motors and sends a blowout signal to indicate the wheel that has blown out.

[0048] In conjunction with the third aspect, in some implementations of the third aspect, the motor controller is used to send a tire blowout signal in response to the fact that within a preset time period, the increase in the rotational speed of the first motor is greater than a first amplitude, the change in the actual output torque is greater than a third amplitude, and the increase in the rotational speed of other motors in the vehicle is less than a second amplitude, and the actual output torque increases after the preset time period; the tire blowout signal is used to indicate that a tire blowout has occurred at the wheel corresponding to the first motor.

[0049] In conjunction with the third aspect, in some implementations of the third aspect, the motor controller is used to send a tire blowout signal in response to the fact that the actual output torque of the first motor is greater than the third amplitude within a preset time period, and the actual output torque increases after the preset time period; the tire blowout signal is used to indicate that the wheel corresponding to the first motor has blown out.

[0050] In some possible embodiments, the motor controller can determine a tire blowout by outputting torque. The torque of a wheel that has blown out will experience a large, step-like fluctuation in a short period of time, and the torque value will increase significantly after stabilization. This characteristic can be used for tire blowout detection.

[0051] In conjunction with the third aspect, in some implementations of the third aspect, the motor controller is used to detect the wheel among the four wheels that has blown out when the vehicle speed is greater than a preset speed.

[0052] In conjunction with the third aspect, in some implementations of the third aspect, the four wheels include two wheels on the left and two wheels on the right. The motor controller is used to control a motor to reduce positive torque output or control a motor to output negative torque when the wheel that has blown out is on a different side from another wheel; and to control a motor to increase positive torque output when the wheel that has blown out is on the same side as another wheel. The direction of positive torque is the same as the direction of rotation of a motor, and the direction of negative torque is opposite to the direction of rotation of a motor.

[0053] 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

[0054] Figure 1 This is an architectural diagram of the vehicle provided in the embodiments of this application;

[0055] Figure 2 This is another vehicle architecture schematic diagram provided in the embodiments of this application;

[0056] Figure 3 This is a schematic diagram of a vehicle signal connection provided in an embodiment of this application;

[0057] Figure 4 This is a schematic diagram of the tire blowout process provided in an embodiment of this application;

[0058] Figure 5 This is another schematic diagram of a tire blowout process provided in an embodiment of this application;

[0059] Figure 6 This is another schematic diagram of tire blowout control provided in an embodiment of this application;

[0060] Figure 7 This is another schematic diagram of tire blowout control provided in an embodiment of this application;

[0061] Figure 8 This is a schematic diagram of a tire blowout control method provided in an embodiment of this application. Detailed Implementation

[0062] 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.

[0063] 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 intended trajectory. In reality, severe high-speed tire blowouts often occur within 0.1 seconds, leaving drivers and the vehicle with extremely limited reaction and control time. Therefore, developing rapid and efficient tire blowout control technologies can significantly improve vehicle stability and controllability after a blowout, ensuring driving safety.

[0064] In one possible implementation, tire blowout detection and control can locate the blowout through tire pressure identification. 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 in each tire. Wheel speed signals collected by wheel speed sensors are then transmitted to the central control module.

[0065] 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 misjudgments.

[0066] In another possible implementation, tire blowout detection and control can identify and locate the blowout by monitoring wheel speed. The control module determines that a tire blowout has occurred when it detects that the rotational speed of one wheel is lower than the rotational speed of any other wheel by a preset ratio.

[0067] It should be understood that the indirect detection method based on wheel speed sensors relies solely on single wheel speed difference information for tire blowout identification, which has a relatively limited application scenario and is very prone to misjudgment.

[0068] Based on the above problems, this application proposes an electric vehicle and method for tire blowout detection and control. The method utilizes a motor resolver sensor to collect the motor speed signal in real time. The central controller, in conjunction with the individual motor controllers, performs signal processing and calculation to identify the results and make a judgment. This method can quickly detect tire blowout faults, locate the faulty wheel, and control it.

[0069] Figure 1 and Figure 2 This is a schematic diagram of the architecture of the electric vehicle 10 provided in an embodiment of this application. (In conjunction with...) Figure 1 and Figure 2 The electric vehicle 10 includes four wheels, four motor controllers, four motors, a central controller 60, a brake controller 70, and four brakes.

[0070] 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.

[0071] 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.

[0072] Based on their position, the wheels can be divided into left front wheels, right front wheels, left rear wheels, and right rear wheels. According to axle arrangement, the left and right front wheels are on the same axle and connected via the front axle, while the left and right rear wheels are on the same axle and connected via the rear axle. According to their position, the left and left rear wheels are on the same side (left side), and the right front and right rear wheels are on the same side (right side). In other words, in the electric vehicle 10, the left and right front wheels are co-axled, the left and right rear wheels are co-axled; the left and left rear wheels are on the same side, the right and right rear wheels are on the same side; the left and right rear wheels are diagonally opposite each other, and the right and left rear wheels are diagonally opposite each other. For example, if the left front tire blows out while the electric vehicle is in motion, the tire on the same side as the tire that blows out is the left rear tire, the tire on the opposite side of the tire that blows out is the right front tire and the right rear tire, the tire on the same axle as the tire that blows out is the right front tire, and the tire diagonally opposite the tire that blows out is the right front tire.

[0073] 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.

[0074] Figure 3 The signal connections between the four motor controllers of the electric vehicle 10 and the central controller 60 are shown.

[0075] In one embodiment, each motor controller includes a signal interface, and each motor controller connects to three other motor controllers through the signal interface, thereby enabling signal interaction between the four motor controllers. The signals exchanged between the four motor controllers include motor speed signals, which indicate the speed of the motor corresponding to each motor controller. In one embodiment, each motor controller can also send torque control signals to the other three motor controllers, which instruct the other three motor controllers to control the output torque of their respective motors. For example, motor controller 21 can send motor speed signals to the other three motor controllers, which indicate the speed of motor 31.

[0076] In one embodiment, each motor controller connects to a resolver sensor via a signal interface. The resolver sensor detects the rotational speed of the motor controlled by the motor controller. The motor controller receives signals from the resolver sensor, generates a rotational speed signal based on the signals, and sends the rotational speed signal to the other three motor controllers. Similarly, each motor controller also receives rotational speed signals from the other three motor controllers. For example, motor controller 21 connects to resolver sensor 51 via signal interface 211. This resolver sensor detects the rotational speed of the motor 31 controlled by motor controller 21. Motor controller 21 receives signals from resolver sensor 51, generates a rotational speed signal based on the signals, and sends the rotational speed signal to the other three motor controllers. Similarly, motor controller 21 also receives rotational speed signals from the other three motor controllers.

[0077] The resolver sensor can accurately detect the position, direction, and speed of the motor rotor, and is responsible for monitoring and extracting the motor's rotational speed. It has a high sampling rate and is directly connected to the motor controller. The motor controller 21 can perform tire blowout detection based on the speed of the four motors. Compared with tire pressure sensor signals, tire blowout detection based on the resolver sensor by the motor controller reduces signal transmission and real-time interaction between different modules, shortens the signal transmission link, and improves the tire blowout detection speed. Both tire blowout detection and control can be completed within the motor system, resulting in higher stability of the control system.

[0078] According to the solution in this application, compared with tire pressure sensor signals via wireless means, tire blowout detection using a motor controller based on a resolver sensor reduces signal transmission and real-time interaction between different modules, shortens the signal transmission link, and improves the tire blowout detection speed. The central controller 60 can receive tire blowout signals from multiple motor controllers after detecting a blowout and can perform consistency verification between the blowout signals output by multiple motor controllers and the wheel where the blowout occurred, reducing the false positive rate.

[0079] Continue reading Figure 2In 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.

[0080] In one embodiment, the central controller 60 is connected to the accelerator pedal. The central controller 60 calculates the 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 of the four motor controllers according to the vehicle torque demand. Each motor controller controls the corresponding motor to output torque to drive the corresponding wheel according to the torque control signal.

[0081] In one embodiment, the central controller 60 is connected to the brake pedal. The central 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.

[0082] 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 central controller and motor controller provided in this application can detect a tire blowout and adjust the torque output to the normal wheels according to the blowout control signal. With the torque output to the three normal wheels working in coordination, the electric vehicle 10 can generate lateral torque, thereby enabling the electric vehicle 10 to be controlled laterally.

[0083] The motor controller provided in this application can simultaneously perform tire blowout detection and tire blowout control functions. It should be emphasized that the motor controller referred to here specifically refers to... Figure 1 (a) or Figure 1 Any one of the four motor controllers shown in (b), that is to say... Figure 1 (a) or Figure 1 (b) Any one of the four motor controllers can implement the tire blowout detection function and tire blowout control function mentioned in the embodiments of this application. Motor controller 21, motor controller 22, motor controller 23 and the fourth motor controller 24 all have the same structure and function. The following embodiment uses motor controller 21 as an example to illustrate the tire blowout detection function.

[0084] The tire blowout detection function of the central controller 60 and motor controller 21 provided in the embodiments of this application will be described in detail below.

[0085] During the operation of the electric vehicle 10, the motor controller 21 is used to detect the wheel among the four wheels that has experienced a tire blowout based on the rotational speed of the four motors. When the electric vehicle 10 is traveling at a speed greater than a preset speed, the motor controller 21 is used to send a tire blowout signal to the central controller 60 in response to any tire blowout at any of the four wheels. The tire blowout signal is used to indicate the wheel that has experienced a tire blowout.

[0086] The central controller 60 receives four tire blowout signals from four motor controllers, including the motor controller 21. Each tire blowout signal indicates the location of the wheel where the blowout occurred.

[0087] Each motor controller in vehicle 10 can perform tire blowout detection independently, resulting in high system redundancy.

[0088] The central controller 60 receives tire blowout signals from the four motor controllers and makes judgments on them. It can also make a comprehensive judgment based on the positions of the wheels that have blown out, as indicated by the four tire blowout signals. If the positions of the wheels that have blown out, as indicated by the four tire blowout signals, are consistent, the judgment is considered correct. If the positions of the wheels that have blown out, as indicated by the four tire blowout signals, are inconsistent, a misjudgment is considered to have occurred.

[0089] According to the scheme of this application, the communication latency between motor controllers is low, and multiple motor controllers are used to perform tire blowout detection and tire blowout wheel positioning independently, thereby improving the redundancy of the tire blowout detection system. By utilizing the speed variation characteristics of distributed motors for wheel blowout detection and identification, the tire blowout detection method based on speed variation characteristics shortens the blowout detection time, allows for timely intervention and control, reduces the false alarm rate and control difficulty, and improves vehicle safety.

[0090] In one embodiment, while the electric vehicle 10 is traveling at a speed greater than a preset speed, in response to a sudden change in the rotational speed of any one of the four motors, the motor controller 21 sends a tire blowout signal. This tire blowout signal indicates that the wheel corresponding to the motor whose rotational speed changed has blown out. Here, a sudden change in the rotational speed of any one of the other four motors means that the increase in the rotational speed of any one of the four motors is greater than the increase in the rotational speed of the other three motors within a preset time period.

[0091] 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 motor controller 21 only detects and locates the blowout wheel by using the rotational speed of the wheel with the blowout and the rotational speeds of other wheels as criteria 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.

[0092] Due to the braking effect of a blowout, the speed of the motor corresponding to the blowout wheel will suddenly increase. Therefore, the motor controller 21 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 speed of other wheels as the judgment criteria.

[0093] In one embodiment, the sudden change in the rotational speed of any one of the four motors further includes, within a preset time period, the increase in rotational speed of the motor whose rotational speed changed is greater than a first amplitude, while the increase in rotational speed of the other three motors is less than a second amplitude, wherein the first amplitude is greater than the second amplitude.

[0094] In response to the electric vehicle 10 having a speed greater than a preset speed, and the speed increase of any one of the four motors being greater than a first amplitude within a preset time period, and the speed increase of the other three motors being less than a second amplitude within the preset time period, the motor controller 21 determines that the wheel corresponding to the motor with the speed increase greater than the first amplitude has blown out.

[0095] Figure 4 A schematic diagram illustrating the motor 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 speeds of the four motors of the electric vehicle 10 were basically the same. At time t0, the speed of motor 32 changed abruptly. During the time period from t0 to t1, the increase in the speed of motor 32 was greater than the first amplitude, while the increase in the speeds of the other three motors was less than the second amplitude. This indicates that the wheel 42 corresponding to motor 32 experienced a tire blowout.

[0096] 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.

[0097] In one embodiment, the rotational speed of any one of the four motors changes abruptly, further including that the change in output torque of the motor whose rotational speed changes abruptly is greater than a third amplitude within a preset time period and increases after the preset time period.

[0098] In response to the following conditions: the speed of the electric vehicle 10 is greater than a preset speed; the speed increase of any one of the four motors is greater than a first amplitude within a preset time period; the change in the output torque of that motor is greater than a third amplitude within a preset time period and increases after the preset time period; and the speed increase of the other three motors is less than a second amplitude within the preset time period, the motor controller 21 determines that the wheel corresponding to the motor whose speed increase is greater than the first amplitude has blown out.

[0099] In one embodiment, the preset duration is less than or equal to the sampling period of the resolver sensor, where the resolver sensor period refers to the interval between two sampling times of the resolver sensor. In another embodiment, the preset duration is the signal interaction time between the four motor controllers, i.e., the preset duration refers to the time period from when motor controller 21 collects the data output by the resolver sensor to when the other three motor controllers receive the speed signals output by motor controller 21. In yet another embodiment, the preset duration is a period of time set as needed. A relatively short preset duration may indicate a tire blowout if the speed of the first wheel motor increases rapidly while the speeds of the other motors remain relatively constant. The first and second amplitude values ​​can be set as needed; different amplitude settings can adjust the sensitivity and false positive rate of the tire blowout detection by motor controller 21.

[0100] The torque output of the motor corresponding to the wheel that has experienced a tire blowout will fluctuate significantly in a short period of time, and then the torque value will increase significantly after stabilization. This characteristic can be used to further determine the cause of the tire blowout. The motor controller 21 can combine the motor speed and the motor output torque as judgment criteria. After determining that a tire blowout has occurred based on the speed, it can judge the output torque of the motor corresponding to the located blown-out wheel. If the output torque of the wheel changes significantly in a short period of time and then stabilizes and is greater than the output torque before the significant change, then it can be confirmed that the wheel has experienced a tire blowout.

[0101] Output torque refers to 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, output torque is more difficult to measure. Output torque can be observed using a motor load monitor. By measuring the motor speed, the output torque can be calculated, thus enabling the monitoring of the output torque.

[0102] According to the solution in this application, tire blowout detection is performed based on motor speed and output torque information, avoiding misjudging tire slippage or freewheeling as tire blowout. The tire blowout detection time is short, the reliability is high, and the misjudgment rate is low.

[0103] Figure 5A schematic diagram illustrating the change in motor output torque corresponding to the wheel that experiences a tire blowout in an electric vehicle 10 is provided. Figure 5 As shown, the change in output torque of a motor whose speed changes abruptly is greater than the third amplitude within a preset time period and increases after the preset time period.

[0104] The following is a detailed description of the specific operation mode of the central controller 60 and motor controller 21 provided in this application for tire blowout control.

[0105] During the driving process of electric vehicle 10 at a speed less than or equal to a preset speed, the central controller 60 outputs torque control signals to the 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.

[0106] When the speed of the electric vehicle 10 is less than or equal to the preset speed, the tire blowout detection function is not triggered, and the central controller 60 will not perform tire blowout detection and control. Therefore, the central 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 travels at low speed.

[0107] In one possible embodiment, the central controller 60 responds to the four tire blowout signals sent by the four motor controllers indicating different wheels. The central controller 60 is used to output torque control signals to the four motor controllers according to the indication of the accelerator pedal. The four motor controllers control the output torque of the four motors according to the indication of the torque control signals.

[0108] After receiving tire blowout signals from the four motor controllers, the central controller can make a comprehensive judgment based on the positions of the wheels where the blowout occurred indicated by the four blowout signals. If the positions of the wheels where the blowout occurred are inconsistent among the four blowout signals, it indicates a false judgment, and no further blowout control is performed. At this time, the central controller 60 determines the torque required to be output by each motor based on the accelerator pedal and / or brake pedal, and sends a torque control signal to instruct each motor controller to control the output torque of each motor.

[0109] In one possible embodiment, the central controller 60 responds to the four tire blowout signals sent by the four motor controllers indicating the same wheel position. The central controller 60 is used to send a tire blowout control signal to each motor controller, which instructs each motor controller to control the corresponding motor to adjust the torque output.

[0110] 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 central controller 60 can detect a tire blowout 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, thereby enabling lateral control of the vehicle.

[0111] At this time, the torque control of the central controller will be decoupled from the accelerator pedal. Since the central controller 60 performs torque control according to the tire blowout control algorithm, the torque output by the four motors controlled by the central 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.

[0112] After determining the location of the tire blowout through the tire blowout detection described above, the central controller 60 adjusts the torque output of the four motors to maintain vehicle stability. For example, if the increase in the rotational speed of motor 32 is greater than the first amplitude within a preset time period, and the increase in the rotational speeds of motors 31, 33, and 34 is less than the second amplitude within the preset time period, the central controller 60 determines that wheel 42 has blown out. The central controller 60 then instructs the motor controller 21 to adjust the torque output of motor 31 to maintain vehicle stability via a tire blowout control signal.

[0113] 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.

[0114] After determining that a tire blowout has occurred, the motor controller 21 sends a blowout signal to the central controller 60. After verifying that the blowout signal matches the blowout signals sent by other motor controllers, the central controller 60 sends a blowout control signal to the motor controller 21 and the other three motor controllers. The blowout control signal is used to instruct the four motor controllers to adjust the torque output of the four motors. Alternatively, the central controller 60 sends a blowout braking signal to the brake controller 70. Under the instruction of the blowout braking signal, the brake controller 70 controls the four brakes to output braking force to maintain vehicle stability.

[0115] In one embodiment, the four wheels include two wheels on the left and two wheels on the right. The motor and motor 31 corresponding to the wheel that blows out are on opposite sides, that is, the wheel that blows out and the wheel driven by motor 31 are on the left and the right respectively. The blowout control signal is used to control motor 31 to reduce torque output.

[0116] If the wheel that has blown out has a motor and motor 31 on opposite sides, that is, the wheel that has blown out and the wheel driven by motor 31 are both on the left or both on the right. The blowout control signal is used to control motor 31 to increase torque output.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] exist Figure 6 In (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.

[0122] 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.

[0123] When an electric vehicle 10 experiences a tire blowout, different control methods can be applied to the normal wheels in different positions. The control priority varies depending on the wheel's location. During blowout control, the central 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 motor's positive torque output 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 motor's positive torque output.

[0124] The central controller 60 sends a first tire blowout control signal to a motor controller corresponding to the wheel on the same axle as the wheel that has blown out. The first tire blowout control signal is used to instruct the motor corresponding to the wheel on the same axle as the wheel that has blown out to reduce its torque output.

[0125] The central controller 60 sends a second tire blowout control signal to a motor controller corresponding to the diagonal wheel of the wheel that has blown out. The second tire blowout control signal is used to instruct the motor corresponding to the diagonal wheel of the wheel that has blown out to reduce the torque output.

[0126] The central controller 60 sends a third tire blowout control signal to a motor controller corresponding to the wheel on the same side as the wheel that has blown out. The third tire blowout control signal is used to instruct the corresponding motor of the wheel on the same side as the wheel that has blown out to increase the torque output.

[0127] 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 has a tire blowout, the central 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.

[0128] 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, 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. During the operation of the electric vehicle 10, wheel 42 experiences a tire blowout. Wheel 41 is the wheel on the same axle as wheel 42, wheel 43 is the diagonal wheel of wheel 42, and wheel 44 is the wheel on the same side as wheel 42. Therefore, firstly, the tire blowout control signal instructs motor controller 21 to control motor 31 to reduce torque output. Then, the tire blowout control signal instructs motor controller 23, corresponding to wheel 43 (which is on a different axle and side from wheel 42), to control motor 33 to reduce torque output. Finally, the tire blowout control signal instructs motor controller 24, corresponding to wheel 44 (which is on the same side and on a different axle from wheel 42), to control motor 34 to reduce torque output.

[0129] In one embodiment, the central 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 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 the control amplitude.

[0130] The status signal of the electric vehicle 10 can be from the sensors of the electric vehicle 10.

[0131] In one embodiment, the central 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 the control amplitude.

[0132] 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 amplitude. When the calculated yaw control torque required to adjust the vehicle's direction of travel is less than or equal to the control amplitude, the motor controller adjusts the output torque to control tire blowout. When the yaw control torque is equal to 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, 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 amplitude, the central controller 60 cannot fully control the vehicle's deviation by simply controlling the motor to adjust the output torque.

[0133] The electric vehicle 10 also includes a braking system. When a tire blowout occurs during the operation of the electric vehicle, the central 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 amplitude.

[0134] This application provides a method for detecting tire blowouts. The method includes:

[0135] 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.

[0136] During the operation of the electric vehicle 10 at a speed exceeding a preset speed, each motor controller sends a tire blowout signal based on the rotational speed changes of the four motors. The tire blowout signal indicates the position of the wheel where the blowout occurred. In response to the four tire blowout signals from the four motor controllers indicating the same wheel position, a tire blowout control signal is sent to each motor controller. The tire blowout control signal instructs each motor controller to adjust the torque output of the corresponding motor.

[0137] During the operation of the electric vehicle 10 at a speed exceeding a preset speed, in response to a sudden change in the speed of any one of the four motors, the torque output of the other three motors is adjusted. A sudden change in the speed of any one of the four motors refers to a situation where, within a preset time period, the increase in the speed of any one of the four motors is greater than the increase in the speed of the other three motors.

[0138] 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.

[0139] When a tire on a vehicle blows out, a "blowout braking effect" occurs, causing a sudden, step-like increase in wheel speed. Utilizing this characteristic, the ratio of the blown-out wheel's speed to that of the other normal tires can be used as a key indicator for diagnosing a blowout. In other words, if the speed increase of any one of the four motors exceeds a first threshold within a preset time period, and the speed increases of the other three motors within the preset time period are all less than a second threshold, it indicates that the wheel corresponding to that motor has blown out. At this point, the other three motors adjust their torque output to maintain vehicle stability.

[0140] For example, if the increase in the speed of motor 32 is greater than the first amplitude within a preset time period and the increase in the speed of motors 31, 33, and 34 is less than the second amplitude within the preset time period, the motor controller 21 determines that wheel 42 has blown out, and motors 31, 33, and 34 adjust their torque output to maintain vehicle stability.

[0141] In one embodiment, the sudden change in the rotational speed of any one of the four motors further includes, within a preset time period, the increase in rotational speed of the motor with the sudden change in rotational speed being greater than a first amplitude, while the increase in rotational speed of the other three motors being less than a second amplitude, wherein the first amplitude is greater than the second amplitude.

[0142] In one embodiment, in response to the electric vehicle 10 having a speed greater than a preset speed, the increase in rotational speed of any one of the four motors being greater than a first amplitude within a preset time period, the change in output torque of that motor being greater than a third amplitude within a preset time period and the output torque of that motor continuing to increase after the preset time period, and the increase in rotational speed of the other three motors being less than a second amplitude within the preset time period, the three motors adjust their torque output.

[0143] The vehicle tire blowout control method provided in this application also includes a blowout misjudgment function. Specifically, after a tire blowout, the motor speed will increase in a step, and the torque of the blown wheel will also fluctuate significantly in a short period of time, and the torque value will increase significantly after stabilization. By utilizing this change characteristic of the blown wheel, the system can further observe the change characteristics of the tire output torque to eliminate situations where tire slippage or spinning is mistakenly judged as a blowout.

[0144] In one embodiment, the torque output adjustment of the other three motors sequentially includes: the motor coaxial with the motor experiencing the speed change first reducing its torque output; the motor not coaxial with and on the opposite side of the motor experiencing the speed change then reducing its torque output; and the motor on the same side as the motor experiencing the speed change then increasing its torque output. The motor experiencing the speed change and the coaxial motor are used to drive the two front wheels or the two rear wheels of the electric vehicle 10, while the motor experiencing the speed change and the motor on the same side are used to drive the two left wheels or the two right wheels of the electric vehicle 10.

[0145] The motor coaxial with the motor driving the wheel that suffered the tire blowout first reduces its torque output, and then the remaining two of the three motors adjust their torque output.

[0146] 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. zThe 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.

[0147] The tire blowout control signal is used to instruct each motor controller to adjust the torque output of the corresponding motor. This includes sequentially outputting a first tire blowout control signal, a second tire blowout control signal, and a third tire blowout control signal. Specifically, the method includes outputting the first tire blowout control signal to the motor controller corresponding to the motor coaxial with the motor whose speed changes abruptly. This first tire blowout control signal instructs the motor coaxial with the motor whose speed changes abruptly to reduce its torque output. The second tire blowout control signal is output to the motor controller corresponding to the motor not coaxial with the motor whose speed changes abruptly and on the opposite side. This second tire blowout control signal instructs the motor not coaxial with the motor whose speed changes abruptly and on the opposite side to reduce its torque output. The third tire blowout control signal is output to the motor controller corresponding to the motor on the same side as the motor whose speed changes abruptly. This third tire blowout control signal instructs the motor on the same side as the motor whose speed changes abruptly to increase its torque output. The motor whose speed changes abruptly and the coaxial motor are used to drive the two front wheels or the two rear wheels of the electric vehicle. The motor whose speed changes abruptly and the motor on the same side are used to drive the two left wheels or the two right wheels of the electric vehicle.

[0148] Figure 8 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.

[0149] 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 amplitude 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 torque that a motor on the normal tire side can apply. If ΔM z <ΔM cIf 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.

[0150] 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.

[0151] In the several embodiments provided in this application, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0152] 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. An electric vehicle with tire blowout detection and control, characterized in that, The electric vehicle includes a central controller, four motor controllers, and four motors. The four motor controllers are used to control the four motors to drive the four wheels of the electric vehicle. Each motor controller is used for: During the operation of the electric vehicle at a speed greater than a preset speed, in response to a sudden change in the rotational speed of any one of the four motors and a corresponding tire blowout, a tire blowout signal is sent to the central controller. The tire blowout signal is used to indicate that the tire corresponding to the motor with the sudden change in rotational speed has blown out. The sudden change in the rotational speed of any one of the four motors means that the increase in the rotational speed of any one of the four motors is greater than the increase in the rotational speed of the other three motors within a preset time period, and the change in the output torque of the motor with the sudden change in rotational speed is greater than the third value within the preset time period and increases after the preset time period. The central controller is used for: In response to the fact that the four tire blowout signals sent by the four motor controllers indicate the same wheel position, a tire blowout control signal is sent to each motor controller, the tire blowout control signal being used to instruct each motor controller to control the corresponding motor to adjust the torque output; In response to the four tire blowout signals sent by the four motor controllers indicating different wheels, the four motor controllers are controlled to output the torque that drives the four motors according to the accelerator pedal indication.

2. The electric vehicle according to claim 1, characterized in that, 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.

3. The electric vehicle according to claim 1 or 2, characterized in that, The central controller is used for: During the operation of the electric vehicle at a speed less than or equal to the preset speed, a torque control signal is output to the 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 signal.

4. The electric vehicle according to claim 1, characterized in that, The sudden change in speed of any one of the four motors further includes: Within a preset time period, the speed increase of the motor whose speed changes abruptly is greater than the first amplitude, while the speed increase of the other three motors is less than the second amplitude, and the first amplitude is greater than the second amplitude.

5. The electric vehicle according to claim 1, characterized in that, The central controller sends a first tire blowout control signal to a motor controller corresponding to the same axle wheel of the wheel that has blown out, a second tire blowout control signal to a motor controller corresponding to the diagonal wheel of the wheel that has blown out, and a third tire blowout control signal to a motor controller corresponding to the same side wheel of the wheel that has blown out. The first blowout control signal is used to instruct the corresponding motor of the wheel on the same axle as the wheel that has blown out to reduce torque output. The second blowout control signal is used to instruct the motor corresponding to the diagonal wheel of the wheel that has blown out to reduce torque output; The third tire blowout control signal is used to instruct the corresponding motor of the wheel on the same side as the wheel that has blown out to increase torque output. The two left wheels of the electric vehicle are wheels on the same side, or the two right wheels of the electric vehicle are wheels on the same side; the two front wheels of the electric vehicle are wheels on the same axle, or the two rear wheels of the electric vehicle are wheels on the same axle; the left front wheel and right rear wheel of the electric vehicle are diagonal wheels, or the right front wheel and left rear wheel of the electric vehicle are diagonal wheels.

6. The electric vehicle according to claim 5, characterized in that, The motor corresponding to the wheel on the same axle as the wheel that experienced the tire blowout first reduces its torque output. The motor corresponding to the diagonal wheel of the wheel that experienced the tire blowout will further reduce its torque output. The motor corresponding to the wheel on the same side as the wheel that experienced the tire blowout will eventually increase its torque output.

7. The electric vehicle according to claim 1, characterized in that, The electric vehicle includes four resolver sensors, which are used to detect the rotational speed of the four motors respectively. Each of the four motor controllers is used to receive the rotational speed signal from one of the four resolver sensors, and the rotational speed signal is used to indicate the rotational speed of one of the four motors. The sudden change in speed of any of the other three motors refers to the increase in speed indicated by a resolver sensor corresponding to any of the other three motors being greater than the increase in speed indicated by a resolver sensor corresponding to the motor within a preset time period.

8. A method for detecting tire blowout, characterized in that, The method is used for electric vehicles, which include four motor controllers and four motors, wherein the four motor controllers are respectively used to control the four motors to drive the four wheels of the electric vehicle. The method includes: During the operation of the electric vehicle at a speed greater than a preset speed, in response to a sudden change in the rotational speed of any one of the four motors and a corresponding tire blowout, each motor controller is used to output a tire blowout signal. The tire blowout signal is used to indicate that the wheel corresponding to the motor with the sudden change in rotational speed has blown out. The sudden change in rotational speed of any one of the four motors means that the increase in the rotational speed of any one of the four motors is greater than the increase in the rotational speed of the other three motors within a preset time period, and the decrease in the output torque of the motor with the sudden change in rotational speed within the preset time period is greater than the third amplitude and increases after the preset time period. In response to the fact that the four tire blowout signals sent by the four motor controllers indicate the same wheel position, a tire blowout control signal is sent to each motor controller, the tire blowout control signal being used to instruct each motor controller to control the corresponding motor to adjust the torque output; In response to the four tire blowout signals sent by the four motor controllers indicating different wheels, the four motor controllers are controlled to drive the four motors to output torque according to the accelerator pedal indication.

9. The method according to claim 8, characterized in that, The sudden change in speed of any one of the four motors further includes: Within a preset time period, the speed increase of the motor whose speed changes abruptly is greater than the first amplitude, while the speed increase of the other three motors is less than the second amplitude, and the first amplitude is greater than the second amplitude.

10. The method according to claim 8, characterized in that, Sending a tire blowout control signal to each of the motor controllers includes: A first tire blowout control signal is sent to a motor controller corresponding to the wheel on the same axle as the wheel that has blown out; a second tire blowout control signal is sent to a motor controller corresponding to the wheel diagonally opposite the wheel that has blown out; and a third tire blowout control signal is sent to a motor controller corresponding to the same side of the wheel that has blown out. The first blowout control signal is used to instruct the corresponding motor of the wheel on the same axle as the wheel that has blown out to reduce torque output. The second blowout control signal is used to instruct the motor corresponding to the diagonal wheel of the wheel that has blown out to reduce torque output; The third tire blowout control signal is used to instruct the corresponding motor of the wheel on the same side as the wheel that has blown out to increase torque output. The two left wheels of the electric vehicle are wheels on the same side, or the two right wheels of the electric vehicle are wheels on the same side; the two front wheels of the electric vehicle are wheels on the same axle, or the two rear wheels of the electric vehicle are wheels on the same axle; the left front wheel and right rear wheel of the electric vehicle are diagonal wheels, or the right front wheel and left rear wheel of the electric vehicle are diagonal wheels.

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