CN115771502A

CN115771502A - Method, device, vehicle and storage medium for controlling a flat-tire vehicle

Info

Publication number: CN115771502A
Application number: CN202211590208.4A
Authority: CN
Inventors: 刘泽; 杨鼎晨; 张洪超; 肖柏宏
Original assignee: Weilai Automobile Technology Anhui Co Ltd
Current assignee: Weilai Automobile Technology Anhui Co Ltd
Priority date: 2022-12-12
Filing date: 2022-12-12
Publication date: 2023-03-10

Abstract

The present invention relates to a technique of controlling a punctured vehicle, and particularly to a method for controlling a punctured vehicle, a vehicle control device, a vehicle, and a computer-readable storage medium. The method comprises the following steps: A. receiving vehicle state information, wherein the vehicle state information comprises real-time tire pressure and vehicle speed; B. judging whether the misoperation of a driver occurs or not based on track planning information generated by the vehicle-mounted intelligent driving module and a steering wheel input corner input by the driver under the condition that the tire pressure and the vehicle speed meet specific conditions; and C, if the driver misoperation is determined to occur, generating a first command based on a longitudinal control strategy for braking and decelerating the vehicle to a safe speed to output to a longitudinal actuator and generating a second command based on a transverse control strategy for maintaining the transverse stability of the vehicle to output to a transverse actuator so as to take over the control of the vehicle instead of the driver.

Description

Method, device, vehicle and storage medium for controlling a flat-tire vehicle

Technical Field

The present invention relates to a technique of controlling a vehicle with a flat tire, and particularly to a method for controlling a vehicle with a flat tire, a vehicle control device, a vehicle, and a computer-readable storage medium.

Background

The moment when the tire burst happens when the automobile runs at high speed has high uncertainty, if the driver operates the tire untimely or excessively excited, the automobile can be out of control or even turn over, and the life and property safety of people in the automobile and other vehicles can be seriously threatened.

At present, some prior arts model a dynamic model of tires of some brands after tire burst based on test data, and perform simulation analysis on vehicle kinematic response after tire burst under different working conditions, and the simulation result shows that the tire burst of a front wheel can cause serious yaw in straight-line driving, the tire burst of a rear wheel can cause the tail flicking of a vehicle to be out of control in curve driving, and the violent operation of a driver can bring greater risk. In the aspect of vehicle stability control after tire burst, some prior arts apply an electronic vehicle body stability control (ESC) model, and adjust the yaw resultant moment borne by the vehicle by using wheel braking force in a differential braking manner after the vehicle has a tire burst, so as to avoid the direction from being out of control.

Disclosure of Invention

To solve or at least alleviate one or more of the above problems, the present invention proposes a method for controlling a punctured vehicle, a vehicle control apparatus, a vehicle, and a computer-readable storage medium, which are capable of reducing the vehicle speed and maintaining the vehicle direction stable as soon as possible after the vehicle has punctured, while avoiding potential risks that may be caused by a driver's erroneous operation.

According to a first aspect of the present invention, there is provided a method for controlling a punctured vehicle, characterized by comprising the steps of: A. receiving vehicle state information, wherein the vehicle state information comprises real-time tire pressure and vehicle speed; B. judging whether the misoperation of the driver occurs or not based on the track planning information generated by the vehicle-mounted intelligent driving module and the steering wheel input corner input by the driver under the condition that the tire pressure and the vehicle speed meet specific conditions; and C, if the driver misoperation is determined to occur, generating a first command based on a longitudinal control strategy for braking and decelerating the vehicle to a safe speed to output to a longitudinal actuator and generating a second command based on a transverse control strategy for maintaining the transverse stability of the vehicle to output to a transverse actuator so as to take over the control of the vehicle instead of the driver.

Alternatively or additionally to the above, in a method according to an embodiment of the invention, the longitudinal actuator is a brake of a chassis brake system of the vehicle and the transverse actuator is an electric power steering motor or a steer-by-wire motor.

Alternatively or additionally to the above, in a method according to an embodiment of the invention, in step B, the tire pressure and the vehicle speed satisfying certain conditions includes: a decrease in the tire pressure during a first period is greater than or equal to a first threshold; and the vehicle speed is greater than or equal to a second threshold.

Alternatively or additionally to the above aspect, in a method according to an embodiment of the invention, step B includes performing the following operations in a case where the tire pressure and the vehicle speed satisfy certain conditions: b1, determining an ideal steering wheel rotation angle when the vehicle runs according to a planned track based on the track planning information; b2, determining a difference value between the ideal steering wheel rotating angle and the steering wheel input rotating angle; and B3, if the absolute value of the difference is larger than a third threshold value, judging that misoperation of the driver occurs.

Alternatively or additionally to the above, in a method according to an embodiment of the present invention, step C includes performing the following operation in a case where it is determined that the driver malfunction occurs: c1, if the average value of the lateral acceleration of the vehicle is larger than a fourth threshold value and the average value of the yaw rate is larger than a fifth threshold value during a second period, determining that the vehicle is in a steering state and performing take-over control on the vehicle according to a steering transverse control strategy and a steering longitudinal control strategy; and C2, if the average value of the lateral acceleration is smaller than or equal to the fourth threshold value during the second period of time and the average value of the yaw rate is smaller than or equal to the fifth threshold value, determining that the vehicle is in a straight-ahead state and performing take-over control on the vehicle according to a straight-ahead transverse control strategy and a straight-ahead longitudinal control strategy.

Alternatively or additionally to the above, in a method according to an embodiment of the invention, in step C1, the taking over control of the vehicle according to the steering lateral control strategy comprises: determining a time domain function of an ideal yaw rate for imparting a uniform deceleration profile motion to the vehicle; determining a mathematical analytic expression of a lane central line where the vehicle is located; substituting the time domain function and the mathematical analytic expression into a single-point preview driver model to obtain a preview deviation between a preview point and the lane center line; and inputting the preview deviation as a feedback quantity into a closed-loop controller, so that the preview deviation is zero and outputting a target steering wheel rotation angle under the preview deviation as the second instruction to the transverse actuator.

Alternatively or additionally to the above, in a method according to an embodiment of the invention, in step C1, the taking over control of the vehicle according to the steering longitudinal control strategy comprises: determining location information of a tire burst based on the tire pressure collected by a tire pressure sensor; if the front wheel on the outer side of the vehicle in the steering direction is flat, applying a first proportion of critical braking pressure to the front wheel on the inner side, applying the critical braking pressure to the rear wheel on the outer side, and determining the braking pressure of the rear wheel on the inner side according to the vertical wheel-load ratio of the rear wheel on the outer side to the rear wheel on the inner side; applying a second proportion of the critical braking pressure to the outboard front wheel and applying the minimum of the critical braking pressure of the outboard rear wheel and the critical braking pressure of the inboard rear wheel to the outboard rear wheel and the inboard rear wheel if the inboard front wheel in the vehicle's steering direction is flat; if the outer rear wheel in the vehicle steering direction is flat, applying a third proportion of the critical braking pressure to the inner front wheel, determining the braking pressure of the outer front wheel according to the vertical wheel-load ratio of the inner front wheel to the outer front wheel, and applying the critical braking pressure to the inner rear wheel; if the inner rear wheel in the vehicle steering direction is flat, applying the critical braking pressure of the inner rear wheel to the outer rear wheel, and applying the minimum value of the critical braking pressure of the outer front wheel and the critical braking pressure of the inner front wheel to the outer front wheel and the inner front wheel; wherein a respective wheel enters a locked state if a brake pressure applied to the respective wheel exceeds its critical brake pressure.

Alternatively or additionally to the above, in a method according to an embodiment of the invention, in step C2, the taking over control of the vehicle according to the straight-ahead lateral control strategy comprises: calculating a first steering wheel corner for keeping the vehicle on the lane center line by using a single-point preview driver model based on the vehicle speed, the lateral displacement of the vehicle center of mass from the lane center line, the center of mass slip angle and the yaw angle; performing closed-loop control on the deviation of the yaw rate from a preset yaw rate to obtain a second steering wheel angle; calculating the sum of the first steering wheel angle and the second steering wheel angle as a target steering wheel angle; and outputting the target steering wheel angle to the lateral actuator as the second instruction.

Alternatively or additionally to the above, in a method according to an embodiment of the invention, in step C2, the taking over control of the vehicle according to the straight-ahead longitudinal control strategy comprises: determining location information of a tire burst based on the tire pressure acquired by a tire pressure sensor; if one of the two rear wheels is flat, applying the critical braking pressure to the rear wheel which is not flat, applying the critical braking pressure to the front wheel on the same side as the flat rear wheel, and determining the braking pressure of the front wheel on the same side as the flat rear wheel according to the vertical wheel-to-load ratio of the two front wheels; if one of the two front wheels is flat, applying the critical braking pressure to the front wheel without flat tire, applying the critical braking pressure to the rear wheel at the same side as the front wheel with flat tire, and determining the braking pressure of the rear wheel at the same side as the front wheel without flat tire according to the vertical wheel-load ratio of the two rear wheels; wherein the respective wheel enters a locking state if the brake pressure applied to the respective wheel exceeds its critical brake pressure.

Alternatively or additionally to the above, a method according to an embodiment of the invention further comprises: D. and when the vehicle speed is less than or equal to the safe speed, the control of the take-over is quitted.

According to a second aspect of the present invention, there is provided a vehicle control apparatus comprising: a memory; a processor; and a computer program stored on the memory and executable on the processor, the execution of the computer program causing the method according to any embodiment of the first aspect of the present invention to be performed.

According to a third aspect of the present invention, there is provided a vehicle comprising: a vehicle-mounted sensor for collecting vehicle state information; and a vehicle control apparatus according to any one of the embodiments of the second aspect of the invention.

According to a fourth aspect of the present invention, there is provided a computer readable storage medium having stored thereon program instructions executable by a processor, the program instructions, when executed by the processor, performing a method according to any of the embodiments of the first aspect of the present invention.

According to the scheme for controlling the tire burst vehicle, the vehicle is subjected to take-over control under the condition that the misoperation of the driver is judged, so that potential risks caused by over-excitation operation of the driver in response to tire burst are avoided. In addition, the scheme for controlling the tire burst vehicle provided by the invention utilizes a longitudinal control strategy to quickly brake and decelerate the tire burst vehicle to a safe speed and utilizes a transverse control strategy to maintain the transverse stability of the tire burst vehicle, so that the movement direction of the tire burst vehicle is stable and the tire burst vehicle can be stopped as soon as possible, the condition that the direction of the vehicle is out of control, the vehicle suddenly changes a lane and collides with other vehicles or obstacles is prevented, and the life and property threats of personnel caused by accidental tire burst are greatly reduced.

Drawings

The above and/or other aspects and advantages of the present invention will become more apparent and more readily appreciated from the following description of the various aspects taken in conjunction with the accompanying drawings, in which like or similar elements are designated with like reference numerals. The drawings include:

FIG. 1 shows a schematic flow diagram of a method 10 for control of a flat-tire vehicle according to one embodiment of the present invention;

FIG. 2 shows a schematic flow diagram of a method 20 for flat tire vehicle control according to one embodiment of the present invention;

FIG. 3 shows the simulation result of the centroid movement locus under the condition of tire burst of the right front wheel when the vehicle runs straight;

FIG. 4 shows the simulation results of yaw rate under the condition of tire burst of the right front wheel when the vehicle is running straight; and

FIG. 5 shows the simulation result of the vehicle speed under the condition of the right front wheel flat tire when the vehicle is running straight.

Detailed Description

In this specification, the invention is described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. The embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

It should be noted that the terms "first", "second", and the like herein are used for distinguishing similar objects, and are not necessarily used for describing a sequential order of the objects in terms of time, space, size, and the like. Furthermore, unless specifically stated otherwise, the terms "comprising," "including," and the like, herein are intended to mean non-exclusive inclusion.

The term "vehicle" or other similar terms herein include motor vehicles in general, such as passenger cars (including sport utility vehicles, buses, trucks, etc.), various commercial vehicles, and the like, and includes hybrid cars, electric cars, plug-in hybrid electric vehicles, and the like. A hybrid vehicle is a vehicle having two or more power sources, such as gasoline powered and electric vehicles.

Hereinafter, exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

Referring now to FIG. 1, FIG. 1 is a schematic flow diagram of a method 10 for flat tire vehicle control in accordance with one embodiment of the present invention. As shown in fig. 1, the method 10 includes the following steps.

In step S110, vehicle state information is received. For example, the vehicle state information may include one or more of tire pressure of a vehicle, vehicle speed, steering wheel input angle input by a driver, lateral acceleration, yaw rate, lane line information where the vehicle is located, and the like. The vehicle state information may be from various onboard sensors in the vehicle (e.g., a tire pressure sensor, an inertial measurement unit IMU, a millimeter wave radar, a lidar, a monocular/binocular camera), a controller in the vehicle (e.g., an electronic control unit ECU), or a cloud server, etc.

In step S120, in the case where the tire pressure and the vehicle speed satisfy the specific condition, it is determined whether a driver malfunction occurs based on the trajectory planning information generated by the in-vehicle intelligent driving module and the steering wheel input rotation angle input by the driver.

Illustratively, whether a tire burst occurs or not is judged according to the amount of change in tire pressure collected by the tire pressure sensor. In one example, if a sharp or slow drop in tire pressure occurs, for example, if the amount of decrease in tire pressure during the first period is greater than or equal to a first threshold value, it is determined that a tire burst occurs in the corresponding tire. In another example, if the tire pressure at a certain time is too low, for example, the tire pressure is less than or equal to the safe tire pressure, it may also be considered that a tire burst has occurred. Further, if it is determined that the tire burst occurs in the vehicle according to the tire pressure, it is continuously determined whether the vehicle with the burst tire is in a high-speed driving state, for example, whether the vehicle speed collected by the speed sensor is greater than or equal to a second threshold value. It is understood that when the flat tire vehicle is in a high-speed driving state, a greater safety risk is caused if a driver malfunction occurs, and therefore it is necessary to further monitor whether the driver malfunction occurs. Because the head of a vehicle in a high-speed running state usually deflects to a certain direction after a tire burst, the vehicle is out of control, and a typical misoperation of a driver shows that a steering wheel is turned at a large angle. It is understood that even a normal vehicle slamming on the steering wheel at high speed can cause a tail flick, slip or rollover, not to mention a blown-out vehicle. Therefore, whether the driver misoperation occurs after the tire burst can be judged according to the input steering angle of the steering wheel of the driver after the tire burst.

Alternatively, in step S120, the following operations are performed in the case where the tire pressure and the vehicle speed satisfy certain conditions: determining an ideal steering wheel angle for driving the vehicle according to the planned track based on the track planning information; determining a difference between the ideal steering wheel angle and the steering wheel input angle; and if the absolute value of the difference is larger than the third threshold, determining that the misoperation of the driver occurs.

For example, if it is determined that the flat-tire vehicle is in a high-speed driving state, the trajectory planning information generated by the vehicle-mounted intelligent driving module (e.g., advanced Driving Assistance System (ADAS)) according to the flat-tire condition is received from the vehicle-mounted intelligent driving module, and the ideal steering wheel rotation angle when the flat-tire vehicle is driven according to the planned trajectory is calculated according to the trajectory planning information

. Next, based on the ideal steering wheel angle

With steering wheel input angle input by driver

The magnitude relationship therebetween determines whether a driver malfunction occurs. It can be understood that if the driver turns the steering wheel at a large angle after tire burst, the ideal steering wheel turning angle for ensuring the vehicle to run according to the safe track is ensured at the moment

From actual steering wheel input angle

The difference in (c) will suddenly become larger. If the driver inputs the steering wheel angle

Angle of rotation from ideal steering wheel

The difference value exceeds a previously set third threshold value

I.e. by

And judging that the driver operates by mistake and further taking over control over the vehicle by the controller instead of the driver.

In step S130, if it is determined that the driver malfunction has occurred, a first command is generated to be output to a longitudinal actuator based on a longitudinal control strategy for braking and decelerating the vehicle to a safe speed and a second command is generated to be output to a lateral actuator based on a lateral control strategy for maintaining lateral stability of the vehicle, in place of the driver taking over control of the vehicle.

As described in the background section, some prior arts adjust the yaw moment applied to the vehicle by using the wheel braking force in a differential braking manner after the vehicle has a tire burst, so as to avoid the direction runaway. The invention creatively provides a longitudinal control strategy which can lead a vehicle running at high speed to be stopped as soon as possible after an accidental tire burst happens, and simultaneously applies a transverse control strategy to limit the motion trail of the vehicle not to exceed the original running lane line, thereby keeping the stability of the running direction after the tire burst and avoiding the possibility of colliding other vehicles or pedestrians by suddenly changing the lane.

Optionally, the longitudinal actuator in step S130 is a brake of a vehicle chassis braking system, and the transverse actuator is an electric power steering motor or a steer-by-wire motor. The electronic power-assisted steering motor which is widely used in recent years is used as an actuator to achieve a better vehicle motion track control effect, active steering can be achieved by applying a steer-by-wire technology, and the steering efficiency and stability are further improved, so that potential hazards caused by violent misoperation of a driver after tire burst are avoided.

Alternatively, the method 10 according to one or more embodiments of the present invention applies different control strategies to the vehicle traveling straight at high speed and the vehicle traveling steered at high speed, that is, the straight-ahead lateral control strategy and the straight-ahead longitudinal control strategy to the vehicle traveling straight at high speed, and the steering lateral control strategy and the steering longitudinal control strategy to the vehicle traveling steered at high speed.

Alternatively, it may be determined that the vehicle is in a straight-ahead state or a turning state based on the vehicle lateral acceleration and the yaw rate collected by the on-vehicle inertial measurement unit IMU. Exemplarily, if the mean value of the lateral acceleration of the vehicle is greater than the fourth threshold value and the mean value of the yaw rate is greater than the fifth threshold value during the second period, determining that the vehicle is in a turning state and taking over control of the vehicle according to the lateral steering control strategy and the longitudinal steering control strategy; and if the average value of the lateral acceleration is less than or equal to a fourth threshold value and the average value of the yaw rate is less than or equal to a fifth threshold value during the second period, determining that the vehicle is in a straight-ahead state and taking over control of the vehicle according to a straight-ahead lateral control strategy and a straight-ahead longitudinal control strategy. The following describes a steering lateral control strategy, a steering longitudinal control strategy, a straight-ahead lateral control strategy, and a straight-ahead longitudinal control strategy, respectively, in accordance with one or more embodiments of the present invention.

Alternatively, in step S130, if it is determined that the vehicle is steering at a high speed, the vehicle is subjected to take-over control according to the following steering lateral control strategy: determining a time domain function of an ideal yaw rate for enabling the vehicle to perform uniform deceleration curve motion; determining a mathematical analytic expression of a lane central line where a vehicle is located; substituting the time domain function and the mathematical analytic expression into a single-point pre-aiming driver model to obtain the pre-aiming deviation between a pre-aiming point and a lane center line; and inputting the preview deviation as a feedback quantity into a closed-loop controller so that the preview deviation is zero and outputting a target steering wheel rotation angle under the preview deviation as a second instruction to a transverse actuator.

As described above, the lateral control strategies (i.e., the steering lateral control strategy and the straight-ahead lateral control strategy) according to one or more embodiments of the present invention are intended to control a vehicle after a tire burst inside a lane in which the vehicle was located before the tire burst, so as to prevent the vehicle from being out of control in direction after the tire burst, and from suddenly changing lanes to hit another vehicle or an obstacle. First, when the steering driving is unexpectedly blown out, it is desirable that the vehicle be stably decelerated in the current lane. Assuming a constant turning radius of the curve, the ideal yaw rate is a decreasing function over time. This function can be used as a target value for the ideal yaw rate, at which time it is ensured that the vehicle is in motion in a uniform deceleration curve. Secondly, a mathematical analytic expression for calculating the center line of the three-dimensional lane where the vehicle is located can be determined based on the existing computer vision technology. The analytic expression can be used as an ideal motion track, and the preview deviation from a preview point to the track can be calculated after the ideal motion track is brought into a single-point preview driver model. In summary, the lane center deviation closed-loop control can be performed by using two conditions, i.e., the time domain function of the ideal yaw angular velocity and the mathematical analytic expression of the lane center line, that is, the preview deviation is input to the closed-loop controller as a feedback quantity, the preview deviation is adjusted to zero by adjusting parameters, and the target steering wheel rotation angle under the preview deviation is output to a transverse actuator (e.g., an electronic power steering motor or a steer-by-wire motor) as a second instruction, so as to ensure that the vehicle is kept in the lane center line during steering.

Alternatively, in step S130, if it is determined that the vehicle is traveling in a high-speed steering, the vehicle is subjected to take-over control according to the following steering longitudinal control strategy: determining location information of a punctured tire based on the tire pressure collected by the vehicle-mounted sensor; applying a first proportion of the critical braking pressure (e.g., 80% of the critical braking pressure of the inner front wheel) to the inner front wheel if the outer front wheel in the vehicle steering direction is flat, applying the critical braking pressure to the outer rear wheel, and determining the braking pressure of the inner rear wheel according to the vertical wheel-to-load ratio of the outer rear wheel to the inner rear wheel; applying a second proportion of its critical braking pressure (e.g., 70% of the critical braking pressure of the outboard front wheel) to the outboard front wheel and applying the minimum of the critical braking pressure of the outboard rear wheel and the critical braking pressure of the inboard rear wheel to the outboard rear wheel and the inboard rear wheel if the inboard front wheel in the vehicle's direction of steering is flat; if the outer rear wheel in the vehicle steering direction is flat, applying a third proportion of the critical braking pressure (for example, 70% of the critical braking pressure of the inner front wheel) to the inner front wheel, determining the braking pressure of the outer front wheel according to the vertical wheel-load ratio of the inner front wheel to the outer front wheel, and applying the critical braking pressure to the inner rear wheel; when the inner rear wheel in the vehicle steering direction is punctured, the critical braking pressure is applied to the outer rear wheel, and the minimum value of the critical braking pressure of the outer front wheel and the critical braking pressure of the inner front wheel is applied to the outer front wheel and the inner front wheel.

It should be noted that the first ratio, the second ratio, and the third ratio mentioned herein are the same value or different values greater than 0 and less than 100%. Preferably, the first proportion, the second proportion and the third proportion are the same value or different values which are greater than 0 and less than or equal to 80%.

It should also be noted that the critical brake pressure mentioned herein approaches the maximum brake pressure at which the wheel reaches the lock-up state at the present moment indefinitely, i.e. if the brake pressure applied to the respective wheel exceeds its critical brake pressure, the respective wheel enters the lock-up state. The critical brake pressure is the brake pressure applied by the brakes and is calculated by the vehicle controller or the anti-lock braking system (ABS) based on the road adhesion coefficient and the vertical wheel load of the respective wheels.

In one example, if the vehicle is turning right and the outer front wheel (i.e., the left front wheel) in the direction of steering is flat, its critical brake pressure is applied to the inner front wheel (i.e., the right front wheel) according to the steering longitudinal control strategy described above

80% of the brake fluid, apply its critical brake pressure to the outboard rear wheel (i.e., the left rear wheel)

And determines the brake pressure of the inner rear wheel based on the vertical wheel-to-load ratio of the outer rear wheel to the inner rear wheel (i.e., the right rear wheel). In this example, if the outboard rear wheel has a vertical wheel load of

The vertical wheel load of the inner rear wheel is

The brake pressure of the inner rear wheel is

. Similarly, in the case of a tire burst of the outer rear wheel in the steering direction of the vehicle, the brake pressure of the outer front wheel can be determined in a similar manner from the vertical wheel-to-load ratio of the two wheels of the front axle.

Alternatively, in step S130, if it is determined that the vehicle is traveling straight at a high speed, the vehicle is subjected to take-over control according to the following straight-ahead lateral control strategy: based on the vehicle speed, the transverse displacement of the center of mass of the vehicle from the center line of the lane, the side slip angle of the center of mass and the yaw angle, calculating a first steering wheel turning angle for keeping the vehicle on the center line of the lane by using a single-point pre-aiming driver model; performing closed-loop control on the deviation of the yaw velocity and the preset yaw velocity to obtain a second steering wheel angle; calculating the sum of the first steering wheel angle and the second steering wheel angle as a target steering wheel angle; and outputting the target steering wheel angle as a second command to the lateral actuator.

In order to control the vehicle after tire burst in the lane where the vehicle is located during tire burst, the transverse displacement of the center of mass of the vehicle, which is generated by vehicle-mounted intelligent driving and deviates from the center line of the lane, is received, the side deviation angle and the yaw angle of the center of mass, which are acquired by inertial navigation, and the vehicle speed information, which is acquired by a vehicle speed sensor, can be acquired, and a first steering wheel corner, which is required for controlling the vehicle in the lane after tire burst, is calculated by using a single-point pre-aiming driver model on the basis of the information

. Further, in order to take comfort into consideration, closed-loop control of yaw rate is introduced, that is, after comparing the yaw rate acquired by inertial navigation with a preset yaw rate and forming a deviation, the yaw rate is inputted to a closed-loop controller (for example, a PID controller), and the control effect is adjusted based on a lag-lead correction to obtain a second steering wheel angle required for reducing the yaw rate

Thereby avoiding the driver from being confused and uncomfortable caused by excessive yaw rate. Finally, the target steering wheel angle is obtained by adding the first steering wheel angle and the second steering wheel angle

And is output as a control command to a lateral actuator (e.g., an electric power steering motor or a steer-by-wire motor).

Alternatively, in step S130, if it is determined that the vehicle is traveling straight at a high speed, the vehicle is subjected to take-over control according to the following straight-ahead longitudinal control strategy: determining location information of a punctured tire based on the tire pressure collected by the vehicle-mounted sensor; if one of the two rear wheels is flat, applying the critical braking pressure to the rear wheel without flat tire, applying the critical braking pressure to the front wheel at the same side as the flat rear wheel, and determining the braking pressure of the front wheel at the same side as the flat rear wheel according to the vertical wheel-load ratio of the two front wheels; if one of the two front wheels is flat, applying the critical braking pressure to the front wheel without flat tire, applying the critical braking pressure to the rear wheel at the same side as the flat front wheel, and determining the braking pressure of the rear wheel at the same side as the flat front wheel according to the vertical wheel-load ratio of the two rear wheels.

When the vehicle runs in a straight line, after the tire bursts, the vehicle wheel is in a suspended state due to lack of air pressure support, and cannot provide vertical force. The sum of the loads at the wheel diagonals at which the wheel is located will drop significantly. Since the total mass of the vehicle is constant, the sum of the loads of the other diagonal lines increases at this time. Just like a table with four supports suddenly breaks with one support, the table will tilt with the line connecting the grounding points of the two supports beside the broken support as the rotation axis. The straight-ahead longitudinal control strategy according to one or more embodiments of the invention applies corresponding brake pressure to the wheel according to the vertical wheel load ratio of the coaxial two wheels, so as to prevent the wheel from locking while ensuring the braking efficiency. According to the characteristics of the tire, the wheel with higher vertical wheel load can generate higher longitudinal adhesion, so that the wheel with larger vertical wheel load after tire burst can be fully utilized to generate enough braking force to help the vehicle to decelerate faster. On the other hand, for a wheel with reduced vertical wheel load, the brake pressure should be reduced appropriately to prevent the wheel from locking, and to avoid losing steering ability or drifting. For a wheel with a burst tire, braking pressure is not applied to the wheel, so that potential safety hazards caused by the fact that the tire is taken off from a rim are avoided.

In one example, if the right front wheel is punctured when the vehicle is traveling straight, the wheel load on the diagonal of the left front-right rear wheels increases after the tire is punctured, and thus the right rear wheel is subjected to its critical brake pressure

Left rear wheel according to the ratio of vertical loads of the left rear wheel and the right rear wheel

Applying brake pressure

. Similarly, under other working conditions of straight-ahead tire burst of the vehicle, the braking pressure can be determined according to the vertical wheel load ratio of two coaxial wheels in a similar manner.

Alternatively, in order to avoid sudden changes in the driver command to the controller command after a tire burst, which may cause a potential safety hazard, the brake pressure and the steering wheel angle may be gradually established in a short time, i.e., the vehicle is gradually taken over, in step S130. In addition, considering that a mechanical system has certain inertia in practical application, if the steering wheel angle changes too fast, excessive dynamic load and inertia force are brought to the steering system, so that the mechanical structure can be damaged, and therefore amplitude limit control and slope limit control can be added to the steering wheel angle control command.

Optionally, the method 10 further includes step S140: if it is determined in step S120 that the driver malfunction has not occurred, a first command is generated to be output to a longitudinal actuator based on a longitudinal control strategy for braking and decelerating the vehicle to a safe speed. If the driver does not operate the steering wheel by mistake after the tire burst of the vehicle running at high speed, the lateral control of the vehicle by the driver can be continued, namely, the vehicle can be controlled based on the steering wheel input steering angle input by the driver. However, since the conventional brake control strategy does not provide an efficient braking effect after a tire burst, and also introduces an additional overall vehicle yaw moment, exacerbating the vehicle yaw, the longitudinal control strategy (e.g., steering longitudinal control strategy, straight-ahead longitudinal control strategy) according to the present invention is immediately enabled whenever a high-speed tire burst condition occurs.

Optionally, the method 10 further includes step S150: and when the vehicle speed is less than or equal to the safe speed, the take-over control is quitted. In consideration of actual driving road conditions, in order to avoid the influence of the vehicle with the tire burst on road resources, the driver can timely recover the control on the vehicle after the vehicle speed is reduced to the safe speed, and the driver can conveniently move the vehicle with the tire burst to the roadside. Since the vehicle speed is low at this time, the object of greatly reducing the risk of collision has already been achieved.

The method 10 according to one or more embodiments avoids potential risks from over-activation of the driver in response to a tire burst by taking over control of the vehicle in the event of a determination that driver malfunction has occurred. In addition, the method 10 according to one or more embodiments utilizes a longitudinal control strategy to rapidly brake and decelerate the punctured vehicle to a safe speed and utilizes a lateral control strategy to maintain the lateral stability of the punctured vehicle, thereby ensuring that the moving direction of the punctured vehicle is stable and the vehicle can stop as soon as possible, preventing the vehicle from losing control of direction, suddenly changing lanes and colliding other vehicles or obstacles, and greatly reducing the life and property threats to people caused by accidental tire burst.

With continued reference to FIG. 2, FIG. 2 is a schematic flow chart of a method 20 for control of a flat-tire vehicle, according to one embodiment of the present invention. As shown in fig. 2, the method 20 includes the following steps.

In step S201, it is determined whether a tire burst has occurred in the vehicle based on the tire pressure information. For example, if the amount of decrease in the tire pressure during the first period is greater than or equal to the first threshold value, it is determined that a tire burst occurs in the corresponding tire. If the tire burst is determined, continuing to step S203; otherwise, the tire pressure is continuously monitored.

In step S203, it is determined whether the vehicle is traveling at a high speed based on the vehicle speed information. Illustratively, it is determined whether the vehicle speed collected by the speed sensor is greater than or equal to a second threshold. If it is determined that the vehicle is traveling at a high speed, step S205 is continued; otherwise, return to step S201.

In step S205, it is determined whether or not a driver malfunction has occurred and it is determined that the vehicle is in a straight-ahead state or a turning state. For the determination process of the driver misoperation, reference may be made to the above description about step S120, which is not repeated herein. The above description of step S130 can be referred to for the judgment flow of the vehicle running state, and the details are not repeated herein.

If it is determined in step S205 that the driver' S erroneous operation has occurred and it is determined that the vehicle is in the straight-ahead state, step S207 is continued. In step S207, a first command is generated to be output to the longitudinal actuator based on the straight-ahead longitudinal control strategy for brake-decelerating the vehicle to a safe speed and a second command is generated to be output to the lateral actuator based on the straight-ahead lateral control strategy for maintaining the lateral stability of the vehicle, in place of the driver' S take-over control of the vehicle.

If it is determined in step S205 that the driver has made a wrong operation and it is determined that the vehicle is in the turning state, step S209 is continued. In step S209, a first command is generated to be output to the longitudinal actuator based on a steering longitudinal control strategy for braking and decelerating the vehicle to a safe speed and a second command is generated to be output to the lateral actuator based on a steering lateral control strategy for maintaining lateral stability of the vehicle, in place of the driver' S take-over control of the vehicle.

If it is determined in step S205 that the driver' S erroneous operation has not occurred and it is determined that the vehicle is in the straight-ahead state, step S211 is continued. In step S211, a first command is generated for output to the longitudinal actuator based on a straight-ahead longitudinal control strategy for decelerating the vehicle brake to a safe speed.

If it is determined in step S205 that the driver' S erroneous operation has not occurred and it is determined that the vehicle is in the turning state, step S213 is continued. In step S213, a first command is generated for output to a longitudinal actuator based on a steering longitudinal control strategy for braking deceleration of the vehicle to a safe speed.

For the specific implementation of the straight-ahead longitudinal control strategy, the straight-ahead lateral control strategy, the steering longitudinal control strategy, and the steering lateral control strategy, reference may be made to the description about step S130, and details are not repeated here.

3-5 show simulation results of a right front wheel flat tire condition when the vehicle is traveling straight. The simulation results shown in fig. 3-5 all list the effects of vehicle control under the following conditions: method 10 or method 20 for applying after a flat tire; the tyre is not burst; no operation is performed after the tire burst; and the driver blindly operates the tire after the tire burst. The driver's blind operation means that the braking strategy proposed by the present invention is not applied, only the maximum pressure at the time of emergency braking of the conventional brake is used as an input, and the braking pressure of the punctured wheel is zero, and the steering wheel is returned to the positive state immediately after the occurrence of the tire burst.

As can be seen from FIG. 3, the vehicle using the

control method

10 or 20 of the present invention can control the maximum lateral distance of the center of mass from the original trajectory to be within 0.015m after the tire is blown out, which can prevent the vehicle from deviating from the original linear trajectory seriously after the tire is blown out and colliding against a guardrail or other vehicles. As can be seen from fig. 4, the

control method

10 or 20 of the present invention greatly reduces the fluctuation range of the yaw rate after the tire burst, improving the comfort of the occupant. As can be seen from fig. 5, the

longitudinal control method

10 or 20 of the present invention can effectively brake and decelerate a flat-tire vehicle quickly to a safe vehicle speed.

According to a second aspect of the present invention, there is provided a vehicle control apparatus comprising: a memory; a processor; and a computer program stored on the memory and executable on the processor, the execution of the computer program causing the method 10 as shown in fig. 1 or the method 20 as shown in fig. 2 to be performed.

According to a fourth aspect of the present invention, there is also provided a computer readable storage medium, on which a computer program is stored, which program, when executed by a processor, performs the method 10 as shown in fig. 1 or the method 20 as shown in fig. 2. The computer-readable storage medium may include Random Access Memory (RAM), such as Synchronous Dynamic Random Access Memory (SDRAM), read-only memory (ROM), non-volatile random access memory (NVRAM), electrically erasable programmable read-only memory (EEPROM), flash memory, other known storage media, and the like.

It is to be understood that some of the block diagrams shown in the figures of the present invention are functional entities and do not necessarily correspond to physically or logically separate entities. These functional entities may be implemented in the form of software, or in one or more hardware modules or integrated circuits, or in different networks and/or processor means and/or microcontroller means.

It should also be understood that in some alternative embodiments, the functions/steps included in the foregoing methods may occur out of the order shown in the flowcharts. For example, two functions/steps shown in succession may be executed substantially concurrently or even in the reverse order. Depending on the functions/steps involved.

In addition, it is easily understood by those skilled in the art that the method for providing driving assistance information provided by one or more embodiments of the present invention described above may be implemented by a computer program. For example, when a computer storage medium (e.g., a USB flash drive) storing the computer program is connected to a computer, the computer program can be executed to perform the method of one or more embodiments of the present invention.

Although only a few embodiments of the present invention have been described in detail above, those skilled in the art will appreciate that the present invention may be embodied in many other forms without departing from the spirit or scope thereof. Accordingly, the present examples and embodiments are to be considered as illustrative and not restrictive, and various modifications and substitutions may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims.

Claims

1. A method for controlling a flat-tire vehicle, comprising the steps of:

A. receiving vehicle state information, wherein the vehicle state information comprises real-time tire pressure and vehicle speed;

B. judging whether misoperation of a driver occurs or not based on track planning information generated by the vehicle-mounted intelligent driving module and a steering wheel input corner input by the driver under the condition that the tire pressure and the vehicle speed meet specific conditions; and

C. and if the driver misoperation is determined to occur, generating a first command based on a longitudinal control strategy for braking and decelerating the vehicle to a safe speed to output to a longitudinal actuator and generating a second command based on a transverse control strategy for maintaining the transverse stability of the vehicle to output to a transverse actuator so as to take over the control of the vehicle instead of the driver.

2. The method of claim 1, wherein the longitudinal actuator is a brake of a vehicle chassis braking system and the lateral actuator is an electric power steering motor or a steer-by-wire motor.

3. The method according to claim 1, wherein, in step B, the tire pressure and the vehicle speed satisfying a certain condition includes:

an amount of decrease in the tire pressure during the first period is greater than or equal to a first threshold value; and

the vehicle speed is greater than or equal to a second threshold.

4. The method according to claim 1, wherein step B includes performing the following operations if the tire pressure and the vehicle speed satisfy a certain condition:

b1, determining an ideal steering wheel rotation angle when the vehicle runs according to a planned track based on the track planning information;

b2, determining a difference value between the ideal steering wheel rotating angle and the steering wheel input rotating angle; and

and B3, if the absolute value of the difference is larger than a third threshold, judging that misoperation of the driver occurs.

5. The method according to claim 1, wherein step C comprises performing the following operations in the event that it is determined that a driver malfunction has occurred:

c1, if the average value of the lateral acceleration of the vehicle is larger than a fourth threshold value and the average value of the yaw rate is larger than a fifth threshold value during a second period, determining that the vehicle is in a steering state and performing take-over control on the vehicle according to a steering transverse control strategy and a steering longitudinal control strategy; and

and C2, if the average value of the lateral acceleration is less than or equal to the fourth threshold value during a second period, and the average value of the yaw rate is less than or equal to a fifth threshold value, determining that the vehicle is in a straight-ahead state, and performing take-over control on the vehicle according to a straight-ahead transverse control strategy and a straight-ahead longitudinal control strategy.

6. The method of claim 5, wherein in step C1, taking over control of the vehicle according to the steer lateral control strategy comprises:

determining a time domain function of an ideal yaw rate for imparting a uniform deceleration profile motion to the vehicle;

determining a mathematical analytic expression of a lane central line where the vehicle is located;

substituting the time domain function and the mathematical analytic expression into a single-point preview driver model to obtain a preview deviation between a preview point and the lane center line; and

and inputting the preview deviation as a feedback quantity into a closed-loop controller so that the preview deviation is zero and outputting a target steering wheel rotation angle under the preview deviation as the second instruction to the transverse actuator.

7. The method according to claim 5, wherein, in step C1, taking over control of the vehicle according to the steering longitudinal control strategy comprises:

determining location information of a tire burst based on the tire pressure acquired by a tire pressure sensor;

if the front wheel on the outer side of the vehicle in the steering direction is flat, applying a first proportion of critical braking pressure to the front wheel on the inner side, applying the critical braking pressure to the rear wheel on the outer side, and determining the braking pressure of the rear wheel on the inner side according to the vertical wheel-load ratio of the rear wheel on the outer side to the rear wheel on the inner side;

applying a second proportion of the critical braking pressure to the outboard front wheel and applying the minimum of the critical braking pressure of the outboard rear wheel and the critical braking pressure of the inboard rear wheel to the outboard rear wheel and the inboard rear wheel if the inboard front wheel in the vehicle steering direction is flat;

if the outer rear wheel in the vehicle steering direction is flat, applying a third proportion of the critical braking pressure to the inner front wheel, determining the braking pressure of the outer front wheel according to the vertical wheel-load ratio of the inner front wheel to the outer front wheel, and applying the critical braking pressure to the inner rear wheel;

if the inner rear wheel in the vehicle steering direction is flat, applying the critical braking pressure of the inner rear wheel to the outer rear wheel, and applying the minimum value of the critical braking pressure of the outer front wheel and the critical braking pressure of the inner front wheel to the outer front wheel and the inner front wheel;

wherein a respective wheel enters a locked state if a brake pressure applied to the respective wheel exceeds its critical brake pressure.

8. The method of claim 5, wherein in step C2, taking over control of the vehicle according to the straight-ahead lateral control strategy comprises:

calculating a first steering wheel corner for keeping the vehicle on the lane center line by using a single-point preview driver model based on the vehicle speed, the lateral displacement of the vehicle center of mass from the lane center line, the center of mass slip angle and the yaw angle;

performing closed-loop control on the deviation of the yaw velocity and a preset yaw velocity to obtain a second steering wheel angle;

calculating the sum of the first steering wheel angle and the second steering wheel angle as a target steering wheel angle; and

outputting the target steering wheel angle to the lateral actuator as the second instruction.

9. The method of claim 5, wherein in step C2, taking over control of the vehicle according to the straight-ahead longitudinal control strategy comprises:

determining location information of a tire burst based on the tire pressure collected by a tire pressure sensor;

if one of the two rear wheels is flat, applying the critical braking pressure to the rear wheel which is not flat, applying the critical braking pressure to the front wheel on the same side as the flat rear wheel, and determining the braking pressure of the front wheel on the same side as the flat rear wheel according to the vertical wheel-to-load ratio of the two front wheels;

if one of the two front wheels is flat, applying the critical braking pressure to the front wheel with the flat tire, applying the critical braking pressure to the rear wheel on the same side as the flat tire front wheel, and determining the braking pressure of the rear wheel on the same side as the flat tire front wheel according to the vertical wheel-to-load ratio of the two rear wheels;

10. The method of claim 1, wherein the method further comprises:

D. and when the vehicle speed is less than or equal to the safe speed, the control of the take-over is quitted.

11. A vehicle control device, characterized by comprising: a memory; a processor; and a computer program stored on the memory and executable on the processor, the execution of the computer program causing the method according to any one of claims 1-10 to be performed.

12. A vehicle, characterized in that the vehicle comprises:

a vehicle-mounted sensor for collecting vehicle state information; and

the vehicle control apparatus according to claim 11.

13. A computer-readable storage medium having instructions stored therein, which when executed by a processor, cause the processor to perform the method of any one of claims 1-10.