CN116729392A

CN116729392A - Vehicle escape auxiliary system and control unit thereof

Info

Publication number: CN116729392A
Application number: CN202311021798.3A
Authority: CN
Inventors: 杨苏; 姚红立
Original assignee: Bosch Automotive Products Suzhou Co Ltd
Current assignee: Bosch Automotive Products Suzhou Co Ltd
Priority date: 2023-08-15
Filing date: 2023-08-15
Publication date: 2023-09-12
Anticipated expiration: 2043-08-15
Also published as: CN116729392B

Abstract

The invention provides a vehicle escape auxiliary system and a control unit thereof. The control unit includes: an acquisition module configured to acquire information related to a running state of the vehicle; a first judging module configured to judge whether a current state of the vehicle is a diagonal wheel unstable state based on the acquired information; the second judging module is configured to judge whether the current state of the vehicle is a collapse state or not based on the acquired information; and a decision module configured to: when the first judging module judges that the current state of the vehicle is an unstable state of the diagonal wheel and the second judging module judges that the current state of the vehicle is a collapse state, a getting-out strategy under the unstable state of the diagonal wheel is decided.

Description

Vehicle escape auxiliary system and control unit thereof

Technical Field

The present invention relates generally to the field of vehicle control. In particular, the present invention relates to a vehicle escape assist system and a control unit thereof.

Background

During the running process of the vehicle, complex and variable road conditions often cause the vehicle to collapse. In this case, an auxiliary tool such as a traction tool may be employed to assist in the escape of the vehicle. However, once the auxiliary tool cannot help the vehicle get stuck, a rescue needs to be requested. This is not an economical and efficient solution and also affects the driving experience.

Disclosure of Invention

Against this background, the present invention aims to provide a solution for vehicle escape that is able to provide a control strategy that assists vehicle escape.

According to an embodiment of the present invention, there is provided a control unit for assisting in vehicle escape, including: an acquisition module configured to acquire information related to a running state of a vehicle, comprising: vehicle speed, wheel speed of each wheel, vehicle body yaw rate, and accelerator pedal depth; a first determination module configured to perform one-sided instability determination, comprising: judging whether the current state of the vehicle is a one-sided unstable state or not based on the acquired information, and judging that the current state of the vehicle is the one-sided unstable state when one of the following conditions is satisfied: 1) One or both of the left front wheel and the left rear wheel of the vehicle are non-stabilizing wheels, and the right front wheel and the right rear wheel of the vehicle are stabilizing wheels; and 2) one or both of the front right wheel and the rear right wheel of the vehicle are non-stabilizing wheels, and the front left wheel and the rear left wheel of the vehicle are both stabilizing wheels, wherein the stabilizing wheels refer to wheels with a wheel speed less than a wheel speed threshold, and the non-stabilizing wheels refer to wheels with a wheel speed not less than the wheel speed threshold; a second determination module configured to perform a sag determination, comprising: judging whether the current state of the vehicle is a collapse state or not based on the acquired information, and judging that the current state of the vehicle is the collapse state when all the following conditions are satisfied: 1) The driving force difference between the driving force of the at least one stabilizing wheel and the driving force of the whole vehicle obtained based on the vehicle mass and acceleration is greater than a driving force difference threshold; 2) The vehicle speed is less than a vehicle speed threshold; 3) The vehicle body yaw rate is less than a vehicle body yaw rate threshold; 4) The depth of the accelerator pedal is greater than the depth threshold of the accelerator pedal; and a decision module configured to decide a getting rid of poverty strategy in case of single-sided instability, comprising: when the first judging module judges that the current state of the vehicle is a unilateral unstable state and the second judging module judges that the current state of the vehicle is a collapse state, determining whether the current state of the vehicle is a single-shaft unstable state or a double-shaft unstable state based on the acquired information, wherein the single-shaft unstable state refers to a state that one of two axles is a stable shaft and the other is an unstable shaft, and the double-shaft unstable state refers to a state that both axles are unstable shafts; and when the determining module determines that the current state of the vehicle is a single-axis unstable state, deciding the following escape strategy: 1) A ratio value of the driving torque allocated to the stable shaft to the driving torque allocated to the unstable shaft is greater than 1; 2) Controlling the driving torque of the stabilizing shaft to increase in a predetermined manner; 3) Increasing the target slip rate of the unstable axis; 4) Increasing braking force to the unstable wheel, and when the current state of the vehicle is determined to be a biaxial unstable state, deciding a escaping strategy as follows: 1) When the gradient of the vehicle running road is zero, uniform driving torque is distributed to the front axle and the rear axle of the vehicle; 2) When the gradient of the vehicle running road is not zero, the axle closer to the center of gravity of the vehicle is assigned a larger driving torque than the axle farther from the center of gravity of the vehicle.

In one example of this embodiment, the ratio value of the driving torque allocated to the stable shaft to the driving torque allocated to the unstable shaft increases as the slip ratio of the unstable shaft increases.

In one example of this embodiment, increasing the target slip rate of the unstable axis includes: increasing the target slip rate of the unstable shaft and making the target slip rate of the unstable shaft inversely related to the vehicle speed; and increasing the target slip rate of the unstable shaft to 2-4 times of the target slip rate of the axle under the normal running condition of the vehicle.

In one example of this embodiment, controlling the drive torque of the stabilizing shaft to increase in a predetermined manner includes: when the increasing speed of the depth of the accelerator pedal is lower than the pedal speed threshold value, the increasing speed of the driving torque of the stable shaft is positively related to the increasing speed of the depth of the accelerator pedal; and limiting the rate of increase of the drive torque of the steady shaft to a current value when the rate of increase of the accelerator pedal depth is not lower than the pedal rate threshold.

In one example of this implementation, the decision module is configured to: when the first judging module judges that the current state of the vehicle is the single-wheel unstable state only based on the acquired information and the second judging module judges that the current state of the vehicle is the collapse state based on the acquired information, the escaping strategy under the single-wheel stable state only is decided.

In one example of this implementation, the decision module is configured to: when the first judgment module judges that the current state of the vehicle is the unstable state of the diagonal wheels based on the acquired information and the second judgment module judges that the current state of the vehicle is the collapse state based on the acquired information, a getting-out strategy under the unstable state of the diagonal wheels is decided.

According to another embodiment of the present invention, there is provided a control unit for assisting in getting rid of a vehicle, including: an acquisition module configured to acquire information related to a running state of a vehicle, comprising: vehicle speed, wheel speed of each wheel, vehicle body yaw rate, and accelerator pedal depth; a first determination module configured to perform only a single round of stability determination, comprising: judging whether the current state of the vehicle is a single-wheel-only stable state based on the acquired information, and judging that the current state of the vehicle is an unstable state when one of the following conditions is satisfied: 1) The left front wheel and the right front wheel are all non-stable wheels, and only one of the left rear wheel and the right rear wheel is a stable wheel; 2) The left rear wheel and the right rear wheel are both non-stabilizing wheels, and only one of the left front wheel and the right front wheel is a stabilizing wheel; a second determination module configured to perform a sag determination, comprising: judging whether the current state of the vehicle is a collapse state based on the acquired information, and judging that the current state of the vehicle is a collapse state when all the following conditions are satisfied: 1) The driving force difference between the driving force of the at least one stabilizing wheel and the driving force of the whole vehicle obtained based on the vehicle mass and acceleration is greater than a driving force difference threshold; 2) The vehicle speed is less than a vehicle speed threshold; 3) The vehicle body yaw rate is less than a vehicle body yaw rate threshold; 4) The depth of the accelerator pedal is greater than the depth threshold of the accelerator pedal; and a decision module configured to decide a getting rid of the problem strategy in a single-round unstable situation only, comprising: when the first judging module judges that the current state of the vehicle is an unstable state and the second judging module judges that the current state of the vehicle is a collapse state, the following escape strategy is decided, wherein the escape strategy comprises the following steps: 1) Allocating less drive torque to the axle coupling both wheels to the non-stabilizing wheel than to the axle coupling one stabilizing wheel and one non-stabilizing wheel; 2) Reducing a target slip ratio of an axle for which both wheels are coupled as unstable wheels; 3) Controlling the driving torque of an axle coupled to one of the stabilizing wheels to increase in a predetermined manner; 4) Increasing a target slip ratio for an axle coupled to one stable wheel and one unstable wheel; 5) The braking force is increased for the non-stationary wheel to which the axle coupling one stationary wheel and one non-stationary wheel is coupled.

In one example of this embodiment, increasing the target slip ratio for the axle coupling one stable wheel and one unstable wheel includes: and increasing the target slip rate of the axle to 2-4 times of the target slip rate of the axle when the vehicle normally runs.

In one example of this embodiment, increasing the braking force for an unstable wheel coupled to an axle coupling one stable wheel and one unstable wheel includes: and increasing the braking force applied to the wheels to be 2-4 times of the braking force applied to the wheels under the condition of normal running of the vehicle.

In one example of this embodiment, controlling the drive torque of an axle coupled to a stabilizing wheel to increase in a predetermined manner includes: when the increase rate of the accelerator pedal depth is lower than the pedal rate threshold value, the increase rate of the driving torque of the axle is positively correlated with the increase rate of the accelerator pedal depth; and limiting the rate of increase of the drive torque of the axle to a current value when the rate of increase of the accelerator pedal depth is not lower than the pedal rate threshold.

In one example of this embodiment, reducing the target slip ratio for the axle where both wheels coupled are unstable wheels includes: and reducing the target slip rate of the axle to 1/4-1/2 of the target slip rate of the axle when the vehicle runs normally.

In one example of this implementation, the decision module is configured to: when the first judging module judges that the current state of the vehicle is a unilateral unstable state based on the acquired information and the second judging module judges that the current state of the vehicle is a collapse state based on the acquired information, a getting-out strategy under the unilateral unstable condition is decided.

According to still another embodiment of the present invention, there is provided a control unit for assisting in getting rid of a vehicle, including: an acquisition module configured to acquire information related to a running state of a vehicle, comprising: vehicle speed, wheel speed of each wheel, vehicle body yaw rate, and accelerator pedal depth; a first determination module configured to perform a diagonal wheel instability determination, comprising: judging whether the current state of the vehicle is a diagonal wheel unstable state based on the sensor information, and judging that the current state of the vehicle is a diagonal wheel unstable state when one of the following conditions is satisfied: 1) The left front wheel and the right rear wheel are unstable wheels, and the right front wheel and the left rear wheel are stable wheels; and 2) the right front wheel and the left rear wheel are non-stabilizing wheels, and the left front wheel and the right rear wheel are stabilizing wheels; a second determination module configured to perform a sag determination, comprising: judging whether the current state of the vehicle is a collapsed state based on the sensor information, and judging that the current state of the vehicle is a collapsed state when all of the following conditions are satisfied: 1) The driving force difference between the driving force of the at least one stabilizing wheel and the driving force of the whole vehicle obtained based on the vehicle mass and acceleration is greater than a driving force difference threshold; 2) The vehicle speed is less than a vehicle speed threshold; 3) The vehicle body yaw rate is less than a vehicle body yaw rate threshold; 4) The depth of the accelerator pedal is greater than the depth threshold of the accelerator pedal; and a decision module configured to: when the first judging module judges that the current state of the vehicle is an unstable state of the diagonal wheel and the second judging module judges that the current state of the vehicle is a collapse state, the following escape strategy is decided: 1) Controlling the driving torque of the front axle and the rear axle of the vehicle to be increased according to a preset mode; 2) Increasing the target slip rate of the stabilizing wheel; 3) The braking force on the non-stationary wheel is increased.

In one example of this embodiment, increasing the target slip rate of the stabilizing wheel includes: and increasing the target slip rate to be 2-4 times of the target slip rate of the wheels when the vehicle normally runs.

In one example of this embodiment, increasing the braking force on the non-stabilized wheel includes: and increasing the braking force to be 2-4 times of the braking force applied to the wheels under the normal running condition of the vehicle.

In one example of this embodiment, controlling the driving torque of both the front axle and the rear axle of the vehicle to be increased in a predetermined manner includes: when the increasing speed of the depth of the accelerator pedal is lower than the pedal speed threshold value, the increasing speeds of the driving torque of the front axle and the rear axle of the vehicle are positively correlated with the increasing speed of the depth of the accelerator pedal; and limiting the rate of increase of the driving torque of the front axle and the rear axle of the vehicle to the current value when the rate of increase of the accelerator pedal depth is not lower than the pedal rate threshold.

In one example of this implementation, the decision module is configured to: when the first judgment module judges that the current state of the vehicle is the single-wheel-only stable state based on the acquired information and the second judgment module judges that the current state of the vehicle is the collapse state based on the acquired information, a getting-out strategy under the single-wheel-only stable condition is decided.

In the examples of the above embodiments, the accelerator pedal depth is obtained based on the accelerator pedal force applied by the driver when the vehicle is in the driver driving mode; or the accelerator pedal depth is calculated by the automatic driving system of the vehicle when the vehicle is in the automatic driving mode.

In the examples of the embodiments described above, in the case where a vehicle axle is coupled with one stable wheel and one unstable wheel, the differential lock on the axle is locked.

In the examples of the above embodiments, the control unit further includes a parking module configured to: detecting whether the driver releases the accelerator pedal based on the acquired information; in response to detecting that the driver releases the accelerator pedal, calculating a driving force capable of stopping the vehicle on the current running ramp; and applying the calculated driving force to the stabilizing wheel and/or the stabilizing axle of the vehicle.

According to yet another aspect of the present invention, there is provided a vehicle escape assist system including: a sensor unit for collecting information related to a running state of a vehicle, comprising: vehicle speed, wheel speed of each wheel, vehicle body yaw rate, and accelerator pedal depth; the control unit is used for deciding a getting rid of the vehicle strategy based on the acquired information; and the execution unit is used for executing the decision-made escape strategy.

The foregoing presents a simplified summary of the primary aspects of the invention in order to provide a basic understanding of such aspects. This summary is not intended to describe key or critical elements of all aspects of the invention nor is it intended to limit the scope of any or all aspects of the invention. The purpose of this summary is to present some implementations of these aspects in a simplified form as a prelude to the more detailed description that is presented later.

Drawings

The technical solution of the present invention will be more apparent from the following detailed description with reference to the accompanying drawings. It is to be understood that these drawings are solely for purposes of illustration and are not intended as a definition of the limits of the invention.

Fig. 1 is a schematic block diagram of a vehicle escape assistance system according to an embodiment of the present invention.

Fig. 2 is a flowchart of a vehicle escape assisting method according to an embodiment of the present invention.

Fig. 3 is a flowchart of a vehicle escape assisting method according to another embodiment of the present invention.

Fig. 4 is a flowchart of a vehicle escape assisting method according to still another embodiment of the present invention.

Detailed Description

The embodiment of the invention relates to a solution for vehicle getting rid of poverty, which can timely and accurately identify different unstable situations of a vehicle, judge whether the vehicle is out of trap after the unstable situations of the vehicle are identified, and execute getting rid of poverty auxiliary operation corresponding to the current condition of the vehicle under the condition that the vehicle is judged to be out of trap.

The vehicle escape assisting scheme provided by the embodiment of the invention is suitable for a driver driving mode and is also suitable for an automatic driving mode. Here, the automatic driving mode includes different levels of automatic driving modes, such as assisted driving, semi-automatic driving, and fully automatic driving.

Herein, the vehicle refers to a four-wheeled vehicle, that is, a vehicle including left and right front wheels coupled to a front axle of the vehicle and left and right rear wheels coupled to a rear axle of the vehicle.

Herein, the unstable situations of the vehicle include: single-side instability (i.e., one or two wheels on the left of the vehicle are unstable and two wheels on the right are stable, or one or two wheels on the right of the vehicle are unstable and two wheels on the left are stable), single-wheel instability only (i.e., one of the four wheels is unstable), and diagonal wheel instability (i.e., two wheels on the diagonal).

Before describing the embodiments of the present invention, some terms that will appear hereinafter are first defined.

Herein, "stabilizing wheel" or "stabilizing wheel" refers to a wheel having a wheel speed less than a wheel speed threshold. In other words, when the wheel speed of a wheel is less than the wheel speed threshold, the vehicle is a stable wheel.

Herein, "unstable wheel" or "unstable wheel" refers to a wheel having a wheel speed not less than the wheel speed threshold. In other words, a wheel is an unstable wheel when the wheel speed of the wheel is not less than the wheel speed threshold.

Here, the wheel speed threshold is predetermined based on real-vehicle experiments and/or model calculations. For example, the wheel speed threshold is predetermined in consideration of the overall vehicle plant requirements and vehicle performance. Furthermore, the wheel speed threshold can also be adjusted according to the specific application scenario. For example, an optimum value is adjusted upward or downward based on a predetermined wheel speed threshold, the direction of adjustment and the optimum value being determined according to the particular application scenario.

Herein, "stable axle" or "stable axle" refers to an axle in which both wheels coupled to the axle are stable wheels.

Herein, "unstable axle" or "unstable axle" refers to an axle in which at least one of the two wheels coupled to the axle is an unstable wheel.

It is noted that various thresholds are employed in embodiments of the present invention, such as wheel speed threshold, vehicle body yaw rate threshold, etc., which may be calculated based on actual vehicle test results and/or models. The invention is not limited to their specific values.

In the following, embodiments of the invention are described with reference to the accompanying drawings.

Fig. 1 shows a vehicle escape assistance system 100 according to an embodiment of the invention, comprising a sensor unit 10, a control unit 20 and an execution unit 30.

The sensor unit 10 is used to provide vehicle running state related information, i.e., sensor information for obtaining a vehicle running state. The sensor unit 10 may include an in-vehicle sensor for sensing a running state of the vehicle, for example, including: a sensor for sensing a vehicle speed, a sensor for sensing a wheel speed of each wheel, a sensor for sensing a lateral acceleration and a longitudinal acceleration of the vehicle, and a sensor for sensing a yaw rate of the vehicle body. It will be appreciated that a variety of vehicle conditions may be obtained directly from the sensor information or indirectly by calculating one or more sensor information. The sensor unit 10 may further include a sensor for receiving information related to a vehicle running state, for example, receiving vehicle running state related information from an edge cloud or cloud server via V2X communication, and obtaining a vehicle running state based on the received vehicle running state related information.

The control unit 20 is communicatively connected to the sensor unit 10 to receive information about the running state of the vehicle and to determine the current state of the vehicle, such as vehicle speed, wheel speed, acceleration and yaw rate of the vehicle body, based on the received information. Next, the control unit 20 determines whether the current state of the vehicle is an unstable state. When it is determined that the current state of the vehicle is an unstable state, the control unit 20 further determines whether the current state of the vehicle is a collapse state. When the current state of the vehicle is determined to be a collapse state, a trapping strategy corresponding to the current state of the vehicle is determined.

Such a control strategy is advantageous because there is a problem in that it is not possible to know in time that the vehicle is in an unstable state, and there is a case in which the vehicle is not subject to collapse although the vehicle is unstable. According to the control strategy provided by the embodiment of the invention, the unstable situation of the vehicle can be timely and accurately judged, the vehicle escaping operation can be ensured to be applied under the condition that the vehicle is in a collapse state, and the false triggering situation that the vehicle escaping operation is applied without the collapse state can not occur, so that the accuracy and the reliability of the vehicle control are improved.

In one embodiment, the control unit 20 includes an acquisition module 21, a first determination module 22, a second determination module 23, a decision module 24, and a parking module 25. It will be appreciated that the naming of these modules is functional and is not intended to limit their implementation or physical location. For example, the modules may be implemented on the same chip or circuit, or may be implemented on different chips or circuits.

The control unit 20 may be implemented in hardware or software or a combination of software and hardware. For portions implemented in hardware, it may be implemented in one or more Application Specific Integrated Circuits (ASICs), digital Signal Processors (DSPs), data Signal Processing Devices (DSPDs), programmable Logic Devices (PLDs), field Programmable Gate Arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, electronic units designed to perform their functions, or a combination thereof. For portions implemented in software, they may be implemented by means of microcode, program code or code segments, which may also be stored in a machine-readable storage medium, such as a storage component.

In one embodiment, the control unit 20 may be provided in an Electronic Control Unit (ECU) of the vehicle, may be provided in a body controller (VCU) of the vehicle, and may be provided in a domain controller of the vehicle.

In one embodiment, the control unit 20 is implemented to include a memory and a processor. The memory contains instructions that, when executed by the processor, cause the processor to perform a method of getting rid of the stuck in accordance with an embodiment of the present invention.

The execution unit 30 is communicatively connected to the control unit 20 for executing a trapping strategy for assisting the trapping of the vehicle, which is decided by the control unit 20. The execution unit 30 comprises, for example, a brake system of the vehicle for executing a brake actuation decided by the control unit 20. The execution unit 30 also comprises, for example, the power system of the vehicle for executing the driving maneuvers decided by the control unit 20.

The vehicle escape assistance solution according to an embodiment of the invention is described below for various vehicle instability situations.

Single side instability

Fig. 2 illustrates a method 200 for vehicle escape assistance in accordance with an embodiment of the present invention. The method 200 may be performed by the control unit 20 described above. The method 200 is designed for a one-sided instability situation of a vehicle.

Referring to fig. 2, at block 210, the acquisition module 21 acquires information related to a vehicle running state, which includes: vehicle speed, wheel speed of each wheel, vehicle body yaw rate, and accelerator pedal depth.

At block 220, the first determination module 22 determines whether the current state of the vehicle is a one-sided unstable state based on the acquired information (e.g., wheel speeds of the wheels). The one-sided unstable state of the vehicle includes two cases (i.e., the following two judgment conditions): 1) One or two wheels on the left side of the vehicle are unstable, and two wheels on the right side of the vehicle are stable; and 2) one or both wheels on the right side of the vehicle are unstable and both wheels on the left side of the vehicle are stable. The definition of the stable wheel and the unstable wheel is referred to the definition of the above terms, and is not repeated.

In one embodiment, determining whether the current state of the vehicle is a one-sided unstable state includes determining whether the following conditions are satisfied based on the received information, and determining that the current state of the vehicle is a one-sided unstable state when one of the following conditions is satisfied: 1) One or two wheels on the left side of the vehicle are unstable, and two wheels on the right side of the vehicle are stable; and 2) one or both wheels on the right side of the vehicle are unstable and both wheels on the left side of the vehicle are stable. In addition, when none of the above conditions is satisfied, the first determination module 22 determines that the current state of the vehicle does not belong to the one-sided unstable state.

At block 230, the second determination module 23 determines whether the current state of the vehicle is a stuck state. The collapse state of the vehicle includes, for example, the following scenarios: the wheels spin at a speed but the vehicle speed is almost zero because the vehicle is trapped and cannot move despite the rapid wheel spin.

In one embodiment, determining whether the current state of the vehicle is a collapsed state includes determining whether the following conditions are satisfied, and determining that the current state of the vehicle is a collapsed state when the following conditions are both satisfied: 1) The driving force difference between the driving force of the at least one stabilizing wheel and the driving force of the entire vehicle based on the vehicle mass and acceleration is greater than a driving force difference threshold; 2) The vehicle speed is less than a vehicle speed threshold; 3) The vehicle body yaw rate is less than a vehicle body yaw rate threshold; 4) The accelerator pedal depth is greater than an accelerator pedal depth threshold. In addition, it is determined that the current state of the vehicle does not belong to the collapse state when at least one of the above conditions is not satisfied.

In general, the above-described conditions for judging the vehicle sag are designed to describe the situation/scenario of the vehicle sag, and when these conditions are satisfied, it may be judged that the vehicle sag. The above-described condition for judging the vehicle sag will be specifically described below.

1) The driving force of the stabilizing wheel refers to the driving force provided to the stabilizing wheel, which can be obtained, for example, by a signal on the vehicle bus. The vehicle driving force based on the vehicle mass and the acceleration may be understood as a vehicle model driving force, which may be obtained by the formula f=m×a, where F represents the vehicle driving force, m represents the vehicle mass, and a represents the acceleration in the vehicle traveling direction. Here, in the case where there are a plurality of wheels, the driving force difference between the driving force of each of the plurality of wheels and the driving force of the entire vehicle may be determined to obtain a plurality of driving force differences. The second determination module 23 determines that the condition is satisfied when at least one of the driving force differences is greater than the driving force difference threshold.

2) If the vehicle is stuck, the vehicle speed should be a small value close to zero because the vehicle is stuck and cannot move. When the vehicle speed obtained from the received information is less than the vehicle speed threshold, the second judgment module 23 judges that the condition is satisfied.

3) If the vehicle is stuck, the body yaw rate should be a small value close to zero because the vehicle is stuck and cannot yaw. When the vehicle body yaw rate obtained based on the sensor information is smaller than the vehicle body yaw rate threshold, the second judgment module 23 judges that the condition is satisfied.

4) When the vehicle is stuck, if the vehicle is in the driver driving mode, the driver may hard step on the accelerator pedal in an attempt to assist the vehicle in getting stuck; if the vehicle is in an autopilot mode, the autopilot system generates a larger accelerator pedal depth command in an attempt to assist in vehicle escape. Therefore, the second determination module 23 determines that the condition is satisfied when the accelerator pedal depth is greater than the accelerator pedal depth threshold, regardless of whether the vehicle is in the driver driving mode or the automatic driving mode.

At block 240, when the first determination module 22 determines that the current state of the vehicle is a unilateral unstable state and the second determination module 23 determines that the current state of the vehicle is a collapsed state, the decision module 24 determines whether the current state of the vehicle is a unilateral unstable state or a biaxial unstable state. The single-axis unstable state refers to a state in which one axle of the vehicle is a stable axis and the other axle is an unstable axis. The biaxial unstable state refers to a state in which both axles of the vehicle are unstable axles. For the definition of axle stability and axle instability, please refer to the above definition section, and the description is omitted.

At block 250, the decision module 24 decides the corresponding escape strategy for the single axis unstable state and the double axis unstable state, respectively.

At block 251, the decision module 24 decides the following escape strategy as determined that the current state of the vehicle is a single-axis unstable state: 1) Distributing a greater driving torque to the stable shaft than the unstable shaft; 2) Controlling the increase rate of the driving torque of the stable shaft to conform to a predetermined curve; 3) Increasing the target slip rate of the unstable axis; 4) The braking force on the non-stationary wheel is increased.

In general, the escape strategy in block 251 is decided for the specific situation in which the vehicle is currently trapped to precisely assist in escaping the vehicle. The escape strategy of each item in block 251 is specifically described below.

1) A larger drive torque is allocated to the stable shaft and a smaller drive torque is allocated to the unstable shaft. That is, the ratio between the driving torque allocated to the stable shaft and the driving torque allocated to the unstable shaft is greater than 1. This ratio increases as the slip ratio of the unstable axis increases. In other words, the ratio is positively correlated with the slip ratio of the unstable axis. The more severe the non-stationary shaft slip, the greater the drive torque allocated to the stationary shaft. The slip ratio of the unstable axle may be determined based on the slip ratio of the two wheels to which the axle is coupled, for example, taking an average of the slip ratios of the two wheels to which the axle is coupled as the slip ratio of the axle.

2) According to the embodiment of the invention, the driving torque increasing rate of the stabilizing shaft is controlled, and the driving torque of the stabilizing shaft is increased to a larger value at a controlled increasing rate. In order to control the driving torque of the stabilizing shaft to increase in a predetermined manner, the rate of increase thereof may be controlled to conform to a predetermined curve. For example, a curve representing the change with time of the driving torque of the stable shaft is plotted, which expresses: when the increasing speed of the depth of the accelerator pedal is lower than the pedal speed threshold value, the increasing speed of the driving torque of the stable shaft is positively related to the increasing speed of the depth of the accelerator pedal; and limiting the rate of increase of the driving torque of the steady shaft to a current value when the rate of increase of the accelerator pedal depth is not lower than the pedal rate threshold, that is, keeping the current value unchanged and prohibiting the rate of increase of the driving torque from continuously becoming larger. Thus, by controlling the rate of increase of the driving torque of the stabilizing shaft to vary according to the plotted curve, it is possible to achieve that the rate of increase of the driving torque of the stabilizing shaft is controlled and conforms to a predetermined control strategy (i.e., plotted curve).

3) The control of the target slip ratio for the unstable axis includes: the target slip ratio of the unstable axis is inversely related to the vehicle speed, i.e., the lower the vehicle speed is, the greater the target slip ratio of the unstable axis is. And, the target slip ratio of the unstable shaft may be increased within a predetermined range, for example, the target slip ratio of the unstable shaft is increased to 2 to 4 times the target slip ratio of the axle under the normal running condition of the vehicle.

4) In order to control the unstable wheel in a high-speed rotation state, braking force is increased thereto. In one embodiment, the braking force of the non-stationary wheel may be increased within a predetermined range, for example, by 2 to 4 times the braking force applied to the wheel in the case of normal running of the vehicle.

At block 252, the decision module 24 decides the following escape strategy as determined that the current state of the vehicle is a two-axis unstable state: 1) When the gradient of the vehicle running road is zero (i.e., a flat road surface), equal driving torque is distributed to the front axle and the rear axle of the vehicle; 2) When the gradient of the vehicle running road is greater than zero (i.e., a non-flat road surface), more driving torque is distributed to the axles closer to the center of gravity.

In general, the escape strategy in block 252 is decided for the specific situation in which the vehicle is currently trapped. Each of the escape strategies in block 252 are described in detail below.

1) The gradient of the vehicle running road may be obtained based on the sensor information. When the gradient of the vehicle running road is zero, that is, the vehicle is running on a flat road surface, the drive torque of the front axle and the drive torque of the rear axle are equally distributed.

2) When the gradient of the vehicle running road is not zero, that is, the vehicle is running on a road surface having a gradient, a larger driving torque is allocated to an axle closer to the center of gravity of the vehicle. In one embodiment, when the vehicle is on an uphill road, the center of gravity of the vehicle is offset toward the rear axle, i.e., the center of gravity of the vehicle is closer to the rear axle than the front axle, the rear axle is assigned a greater drive torque than the front axle. Also, the larger the gradient, the larger the ratio between the drive torque allocated to the rear axle and the drive torque allocated to the front axle, that is, the larger the gradient, the larger the drive torque allocated to the rear axle. In another embodiment, when the vehicle is on a downhill road, the center of gravity of the vehicle is offset toward the front axle, i.e., the center of gravity of the weight is closer to the front axle than the rear axle, the front axle is assigned a greater drive torque than the rear axle. Further, the larger the gradient, the larger the ratio between the drive torque allocated to the front axle and the drive torque allocated to the rear axle, that is, the larger the gradient, the larger the drive torque allocated to the front axle.

Single wheel only stabilization

Fig. 3 illustrates a vehicle escape assistance method 300 according to another embodiment of the invention. The method 300 may be performed by the control unit 20 described above. The method 300 is designed for a single wheel only stabilization situation of a vehicle.

Referring to fig. 3, at block 310, the acquisition module 21 acquires information related to the vehicle running state, which includes: vehicle speed, wheel speed of each wheel, vehicle body yaw rate, and accelerator pedal depth.

At block 320, the first determination module 22 determines whether the current state of the vehicle is a single wheel only steady state based on the received information (e.g., wheel speeds of the wheels). The single-wheel-only steady state of the vehicle includes two cases (i.e., the following two judgment conditions): 1) The left front wheel and the right front wheel are unstable, and only one wheel of the left rear wheel and the right rear wheel is stable; 2) The left and right rear wheels are unstable, and only one of the left and right front wheels is stable. The definition of wheel stability and wheel instability is given in the definition section of the above terms, and is not repeated.

In one embodiment, determining whether the current state of the vehicle is a single-wheel-only steady state comprises: judging whether the following conditions are satisfied based on the received information, and judging that the current state of the vehicle is a single-wheel-only stable state when one of the following conditions is satisfied: 1) The left front wheel and the right front wheel are unstable, and only one wheel of the left rear wheel and the right rear wheel is stable; 2) The left and right rear wheels are unstable, and only one of the left and right front wheels is stable. The definition of stabilizing wheels and non-stabilizing wheels is given in the definition section of the above terms. In addition, when none of the above conditions is satisfied, the first determination module 22 determines that the current state of the vehicle does not belong to the single-wheel-only steady state.

At block 330, the second determination module 23 determines whether the current state of the vehicle is a stuck state. The determination method in the block 330 is referred to the above description about the block 230, that is, the description of the block 230 is also applicable to this, and is not repeated here.

At block 340, when the first determination module 22 determines that the current state of the vehicle is unstable for only one wheel and the second determination module 23 determines that the current state of the vehicle is a stuck state, the decision module 24 decides a stuck-free strategy as follows: 1) Distributing less drive torque to an axle coupled to two non-stationary wheels than to an axle coupled to one stationary wheel and one non-stationary wheel; 2) For an axle coupled to two non-stationary wheels, decreasing its target slip ratio and for an axle coupled to one stationary wheel and one non-stationary wheel increasing its target slip ratio; 3) Controlling the driving torque of an axle coupled to a stabilizing wheel and an unstable wheel to conform to a predetermined curve; 4) For an unstable wheel on an axle coupled to one stable wheel and one unstable wheel, the braking force is increased.

In general, the escape strategy in block 340 is decided for the specific situation in which the vehicle is currently trapped. The escape strategy of each of the blocks 340 is specifically described below.

1) In the single-wheel-only stabilization case, one of the two axles of the vehicle is an axle coupling two non-stabilized wheels, and the other is an axle coupling one stabilized wheel and one non-stabilized wheel. In this case, the drive torque allocated to the axle coupled to one stable wheel and one unstable wheel is larger than the drive torque allocated to the axle coupled to two unstable wheels, that is, the axle coupled to one stable wheel and one unstable wheel is made to obtain more driving force.

2) The target slip ratio of the axle coupled to the two unstable wheels is reduced, for example, by 1/4 to 1/2 of the target slip ratio of the axle when the vehicle is running normally. Further, the target slip ratio of the axle coupled to one stable wheel and one unstable wheel is increased, for example, by 2 to 4 times the target slip ratio of the axle when the vehicle is running normally.

3) According to the embodiment of the present invention, the rate of increase of the driving torque of the stabilizing shaft is controlled, and the driving torque of the stabilizing shaft is caused to increase to a larger value in a manner that the rate of increase is controlled. For a description of this manipulation, please refer to the description of the manipulation 2) in the box 251, that is, the description of the manipulation 2) in the box 251 is also applicable here, and is not repeated.

4) For an axle coupled to one stable wheel and one unstable wheel, the braking force on the unstable wheel on the axle is increased. Because the wheel speed difference of the two wheels coupled is too large for the axle, i.e. the non-stationary wheel rotates at a high speed and the stationary wheel rotates at a relatively much lower wheel speed, which can cause mechanical damage to the axle. In this regard, increasing the braking force on the non-stationary wheel to which the axle is coupled can reduce mechanical damage to the axle caused by wheel speed differences. For example, the braking force of the unstable wheel coupled to the axle is increased by 2 to 4 times the braking force applied to the wheel in the normal running situation of the vehicle.

Unstable diagonal wheel

Fig. 4 illustrates a vehicle escape assistance method 400 according to yet another embodiment of the invention. The method 400 may be performed by the control unit 20 described above. The method 400 is designed for a diagonal wheel instability situation of a vehicle.

Referring to fig. 4, at block 410, the acquisition module 21 acquires information related to the vehicle running state, which includes: vehicle speed, wheel speed of each wheel, vehicle body yaw rate, and accelerator pedal depth.

At block 420, the first determination module 22 determines whether the current state of the vehicle is a diagonal wheel unstable state based on the received information (e.g., wheel speeds of the wheels). The wheel-setting unstable state of the vehicle includes two cases (i.e., the following two judgment conditions): 1) The left front wheel and the right rear wheel are unstable, and the right front wheel and the left rear wheel are stable; and 2) the right front wheel and the left rear wheel are unstable, and the left front wheel and the right rear wheel are stable. The definition of wheel stability and wheel instability is given in the definition section of the above terms, and is not repeated.

In one embodiment, determining whether the current state of the vehicle is a diagonal wheel unstable state based on the received information includes determining whether the following conditions are met based on the sensor information, and determining that the current state of the vehicle is a diagonal wheel unstable state when one of the following conditions is met: 1) The left front wheel and the right rear wheel are unstable, and the right front wheel and the left rear wheel are stable; and 2) the right front wheel and the left rear wheel are unstable, and the left front wheel and the right rear wheel are stable. When none of the above conditions is satisfied, it is determined that the current state of the vehicle does not belong to the caster unstable state.

At block 430, the second determination module 23 determines whether the current state of the vehicle is a stuck state. The determination method in the block 430 is referred to the above description about the block 230, that is, the description of the block 230 is also applicable to this, and is not repeated here.

At block 440, when the first determination module 22 determines that the current state of the vehicle is a diagonal wheel unstable state and the second determination module 23 determines that the current state of the vehicle is a stuck state, the decision module 24 decides a stuck-at-prevention strategy as follows: 1) Controlling the increase rates of the driving torque of the front axle and the driving torque of the rear axle of the vehicle to meet a preset curve; 2) Increasing the target slip rate of the stabilizing wheel; 3) The braking force on the unstable wheel is increased.

In general, the escape strategy in block 440 is decided for the specific situation in which the vehicle is currently trapped. The escape strategy of each of the blocks 440 is described in detail below.

1) In this case, both the driving torque of the front axle and the driving torque of the rear axle are caused to increase to a larger value at a controlled rate of increase. The control of the rate of increase of the driving torque of the front axle and the control of the rate of increase of the driving torque of the rear axle can be referred to the description of the manipulation 2) in the block 251, i.e., the description of the manipulation 2) in the block 251 is equally applicable thereto, and is not repeated.

2) In this case, the front and rear axles are both: coupled to a stabilizing wheel and an non-stabilizing wheel. The slip ratio of the non-stabilized wheel is relatively large and the slip ratio of the stabilized wheel is relatively small. At this time, increasing the target slip rate of the stabilizing wheel can bring the slip amounts of the two wheels coupled by the same axle closer to each other rather than the gap being larger and larger, thereby causing mechanical damage to the axle.

3) In this case, the front and rear axles are both: coupled to a stabilizing wheel and an non-stabilizing wheel. The wheel speed of the non-stabilized wheel is relatively large, while the wheel speed of the stabilized wheel is relatively small. At this time, increasing the braking force on the unstable wheel can make the wheel speeds of the two wheels coupled by the same axle more similar, rather than the difference being larger and larger, thereby causing mechanical damage to the axle.

It is to be understood that, in the control policy of each scenario described above, the order of the judgment performed by the first judgment module and the judgment performed by the second judgment module is not limited. In other words, the two judgment modules may be judged simultaneously, or there may be a sequence. In addition, when at least one of the first judging module and the second judging module judges that the judging result is negative, the corresponding escaping decision is not executed. For example, for a one-sided unstable scenario, if the first determination module determines that the current state of the vehicle does not belong to a one-sided unstable state or the second determination module determines that the current state of the vehicle does not belong to a collapsed state, then a tie-down policy for one-sided unstable state decisions is not executed.

In addition, according to embodiments of the present invention, for axles coupled to one stabilizing wheel and one non-stabilizing wheel, the following maneuvers may also be decided: locking the differential on the axle. This is advantageous, for example, in that the drive capacity of the stabilizing wheels can be utilized to a maximum extent and also in that excessive wheel speed differences can be avoided leading to damage to the differential lock.

The manipulation of this embodiment is applicable to the scenes/embodiments described above. That is, regardless of the unstable condition or the unstable condition of the current condition of the vehicle, once an axle is coupled to one stable wheel and one unstable condition occurs, a decision is made to lock the differential lock on the axle, and thus a manipulation to lock the differential lock is performed.

According to an embodiment of the present invention, the vehicle escape assistance system 100 further comprises a parking module 25 for assisting in parking the vehicle. Considering that there may be a stop-and-go situation when the vehicle is traveling on an off-road, for example, when the vehicle is traveling on a narrow mountain road, the driver may need to temporarily stop and go out of the window to observe the surrounding environment and then start the vehicle. For such a scenario, the parking module 25 provides a control strategy that assists the vehicle in parking so that the driver is relaxed.

In one embodiment, the parking module 25 detects whether the driver releases the accelerator based on the sensor information, calculates a driving force capable of stopping the vehicle on the current travel ramp upon detecting that the driver releases the accelerator pedal, and causes the driving force to be applied to the stabilizing wheels and/or stabilizing axle of the vehicle, thereby controlling the parking of the vehicle. According to this embodiment, the signal indicating that the driver releases the accelerator pedal is a trigger signal that triggers the vehicle to stop, and the stop module executes the above-described stop control strategy in response to the trigger signal.

The present invention also provides in a further aspect a machine readable storage medium storing executable instructions that when executed cause one or more processors to perform a vehicle escape assistance method as described above.

It should be noted that all operations in the methods described above are merely exemplary, and the present disclosure is not limited to any operations in the methods or the order of such operations, but rather should cover all other equivalent variations under the same or similar concepts.

It should be noted that the processor may use any combination of one or more of the following: suitable central processing units, CPUs, multiprocessors, single chip microcomputer, digital signal processors, DSPs, application specific integrated circuits, etc. are capable of executing software instructions of a computer program stored in a memory. Thus, the memory may be considered as part of or form part of a computer program product. The processor may be configured to execute a computer program stored therein to cause the controller to perform the required steps.

It should be noted that software should be construed broadly to mean instructions, instruction sets, code segments, program code, programs, subroutines, software modules, applications, software packages, routines, subroutines, objects, threads of execution, procedures, functions, and the like. The software may reside in a computer readable medium. Computer-readable media may include, for example, memory, which may be, for example, a magnetic storage device (e.g., hard disk, floppy disk, magnetic strips), optical disk, smart card, flash memory device, random Access Memory (RAM), read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically Erasable PROM (EEPROM), registers, or removable disk. Although the memory is shown separate from the processor in various aspects presented in this disclosure, the memory may also be located internal to the processor (e.g., in a cache or register).

The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Accordingly, the claims are not intended to be limited to the aspects shown herein. All structural and functional equivalents to the elements of the various aspects described herein that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims.

Claims

1. A control unit for assisting in vehicle escape, comprising:

an acquisition module configured to acquire information related to a running state of a vehicle, comprising: vehicle speed, wheel speed of each wheel, vehicle body yaw rate, and accelerator pedal depth;

a first determination module configured to perform a diagonal wheel instability determination, comprising: judging whether the current state of the vehicle is a diagonal wheel unstable state based on the sensor information, and judging that the current state of the vehicle is a diagonal wheel unstable state when one of the following conditions is satisfied: 1) The left front wheel and the right rear wheel are unstable wheels, and the right front wheel and the left rear wheel are stable wheels; and 2) the right front wheel and the left rear wheel are non-stabilizing wheels, and the left front wheel and the right rear wheel are stabilizing wheels;

A second determination module configured to perform a sag determination, comprising: judging whether the current state of the vehicle is a collapsed state based on the sensor information, and judging that the current state of the vehicle is a collapsed state when all of the following conditions are satisfied: 1) The driving force difference between the driving force of the at least one stabilizing wheel and the driving force of the whole vehicle obtained based on the vehicle mass and acceleration is greater than a driving force difference threshold; 2) The vehicle speed is less than a vehicle speed threshold; 3) The vehicle body yaw rate is less than a vehicle body yaw rate threshold; 4) The depth of the accelerator pedal is greater than the depth threshold of the accelerator pedal; and

a decision module configured to: when the first judging module judges that the current state of the vehicle is an unstable state of the diagonal wheel and the second judging module judges that the current state of the vehicle is a collapse state, the following escape strategy is decided: 1) Controlling the driving torque of the front axle and the rear axle of the vehicle to be increased according to a preset mode; 2) Increasing the target slip rate of the stabilizing wheel; 3) The braking force on the non-stationary wheel is increased.

2. The control unit of claim 1, wherein increasing the target slip rate of the stabilizing wheel comprises: and increasing the target slip rate to be 2-4 times of the target slip rate of the wheels when the vehicle normally runs.

3. The control unit of claim 1, wherein increasing the braking force on the non-stabilized wheel comprises: and increasing the braking force to be 2-4 times of the braking force applied to the wheels under the normal running condition of the vehicle.

4. The control unit according to claim 1, wherein controlling the driving torque of both the front axle and the rear axle of the vehicle to be increased in a predetermined manner includes:

when the increasing speed of the depth of the accelerator pedal is lower than the pedal speed threshold value, the increasing speeds of the driving torque of the front axle and the rear axle of the vehicle are positively related to the increasing speed of the depth of the accelerator pedal; and

when the rate of increase of the accelerator pedal depth is not lower than the pedal rate threshold value, the rate of increase of the drive torque of both the front axle and the rear axle of the vehicle is limited to the current value.

5. The control unit of claim 1, wherein the accelerator pedal depth is obtained based on a driver applied accelerator pedal force when the vehicle is in a driver driving mode; or alternatively

The accelerator pedal depth is calculated from an automatic driving system of the vehicle when the vehicle is in an automatic driving mode.

6. The control unit of claim 1, wherein the decision module is configured to:

when the first judging module judges that the current state of the vehicle is a unilateral unstable state based on the acquired information and the second judging module judges that the current state of the vehicle is a collapse state based on the acquired information, a getting-out strategy under the unilateral unstable condition is decided.

7. The control unit of claim 1, wherein the decision module is configured to:

when the first judgment module judges that the current state of the vehicle is the single-wheel-only stable state based on the acquired information and the second judgment module judges that the current state of the vehicle is the collapse state based on the acquired information, a getting-out strategy under the single-wheel-only stable condition is decided.

8. The control unit of any one of claims 1-7, wherein a differential lock on an axle is locked with the axle coupled to a stabilizing wheel and an non-stabilizing wheel.

9. The control unit of any of claims 1-7, further comprising: a parking module configured to:

detecting whether the driver releases the accelerator pedal based on the acquired information;

in response to detecting that the driver releases the accelerator pedal, calculating a driving force capable of stopping the vehicle on the current running ramp; and

the calculated driving force is applied to the stabilizer wheel and/or the stabilizer shaft of the vehicle.

10. A vehicle escape assist system comprising:

a sensor unit for collecting information related to a running state of a vehicle, comprising: vehicle speed, wheel speed of each wheel, vehicle body yaw rate, and accelerator pedal depth;

The control unit of any one of claims 1-9, configured to determine a vehicle's stay-away strategy based on the obtained information; and

and the execution unit is used for executing the decision-made escape strategy.