Steering control method and device when autonomous driving takes over

Abstract

The application provides a steering control method and device when automatic driving is taken over, and relates to the technical field of automatic driving. The method comprises the following steps: acquiring a steering force applied on a steering column by a steering machine when a driver takes over; and controlling a power-assisted system to apply a resistance force decreasing over time on the steering machine, so that the steering machine releases the steering force under the action of the resistance force. The application avoids the problem of poor vehicle lateral stability caused by the sudden release of the steering force by the steering machine.

Description

Technical Field

[0001] This invention relates to the field of autonomous driving technology, and in particular to a steering control method and apparatus for autonomous driving takeover. Background Technology

[0002] During autonomous driving, if the autonomous driving system or driver assistance system encounters a situation that it cannot handle, the driver needs to actively take over the system. This takeover can be achieved by pressing the brake pedal or by directly turning the steering wheel. In classic driver assistance systems, lateral steering control is achieved through an electronically controlled steering gear. Under the control of the driver assistance system, the electronically controlled steering gear applies steering control force to the steering wheel to achieve automatic lateral steering. During automatic lateral control, if the driver forcibly takes over, whether by pressing the brake pedal or forcibly turning the steering wheel, the steering system will immediately release the stress applied to the steering column, returning control to the driver.

[0003] Specifically, when taking over steering, if the control force previously applied to the steering wheel was to the left, but the driver actually applies control force to the right, the steering system will detect the reverse of the control torque and determine that the driver has taken over. After taking over, under the control of the driver assistance system, the steering system will remove the original control force. Losing its proper balance, the steering gear will turn sharply to the right, greatly increasing the likelihood of oversteer. The driver will then adjust the steering wheel left and right until the vehicle stabilizes, which can create safety hazards at high speeds. The same applies to left turns.

[0004] When the brake pedal is used to take over, if the system previously had left-direction control, pressing the brake pedal will disengage the left-direction control. If the driver does not maintain control of the steering wheel at this point, the steering wheel will naturally release and move towards the zero position, causing vehicle sway and affecting high-speed driving safety. The same applies to right turns.

[0005] Therefore, regardless of the method of takeover, if the steering system immediately releases the stress applied to the steering column, it will cause the vehicle body to sway and the vehicle's lateral stability to be poor. Summary of the Invention

[0006] This invention provides a steering control method and apparatus for autonomous driving takeover, which solves the problems of vehicle body swaying and poor lateral stability when the vehicle is taken over in the prior art.

[0007] This invention provides a steering control method during autonomous driving takeover, comprising:

[0008] When the driver takes over, the steering force applied to the steering column by the steering gear is obtained;

[0009] The power steering system applies a resistance to the steering gear that decreases over time, so that the steering gear releases the steering force under the action of the resistance.

[0010] According to a steering control method for automatic driving takeover provided by the present invention, the control assist system applies a resistance to the steering gear that decreases over time, comprising:

[0011] The initial resistance is initialized to the magnitude of the steering force, and its direction is the same as that of the steering force;

[0012] Starting from time 0, the real-time resistance is calculated based on the relationship between the initial resistance and the preset resistance decreasing over time, and the power assist system is controlled to apply the real-time resistance to the steering gear.

[0013] According to the steering control method for automatic driving takeover provided by the present invention, the relationship between the decrease of resistance and time is as follows:

[0014] N(t) = N0 - α·t

[0015] N0 = F

[0016] Where t is time, N(t) is real-time resistance, N0 is initial resistance, F is steering force, α is time coefficient, and α>0.

[0017] According to the present invention, a steering control method for automatic driving takeover further includes: acquiring the lateral acceleration of the vehicle when the driver takes over, wherein the control assist system applies a resistance to the steering gear that decreases over time, including:

[0018] The initial resistance is initialized to the magnitude of the steering force, and its direction is the same as that of the steering force;

[0019] Starting from time 0, the real-time resistance is calculated based on the initial resistance, the lateral acceleration, and the preset relationship between the resistance and time, and the power assist system is controlled to apply the real-time resistance to the steering gear.

[0020] According to the steering control method for automatic driving takeover provided by the present invention, the relationship between the decrease of resistance and time is as follows:

[0021]

[0022] Where A(t) is the lateral acceleration, β is the proportionality coefficient, and β>0.

[0023] According to the present invention, a steering control method for automatic driving takeover is provided, wherein β satisfies 1 < β < 20.

[0024] The steering control method for automatic driving takeover provided by the present invention further includes: adjusting the β value in real time according to the change of the lateral acceleration, such that the smaller the lateral acceleration, the larger the β value, and the larger the lateral acceleration, the smaller the β value.

[0025] The present invention also provides a steering control device for automatic driving takeover, comprising:

[0026] The steering force acquisition module is used to acquire the steering force applied to the steering column by the steering gear when the driver takes over.

[0027] A resistance application module is used to control the power assist system to apply a resistance that decreases over time to the steering gear, so that the steering gear releases the steering force under the action of the resistance.

[0028] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steering control method for automatic driving takeover as described above.

[0029] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steering control method for automatic driving takeover as described above.

[0030] The present invention provides a steering control method and apparatus for automatic driving takeover, which obtains the steering force applied to the steering column by the steering gear when the driver takes over; controls the power assist system to apply a resistance that decreases over time to the steering gear, so that the steering gear releases the steering force under the action of the resistance, thereby avoiding the problem of vehicle body swaying and poor lateral stability caused by the steering gear suddenly releasing the steering force or the driver applying a reverse steering force at the same time as releasing the steering force. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0032] Figure 1 This is a flowchart illustrating the steering control method for autonomous driving takeover provided by the present invention;

[0033] Figure 2 This is a schematic diagram of the steering control device for automatic driving takeover provided by the present invention;

[0034] Figure 3This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0036] The steering control method for automatic driving takeover in this embodiment of the invention, such as... Figure 1 As shown, it includes:

[0037] Step S110: Obtain the steering force applied to the steering column by the steering gear when the driver takes over. When the driver takes over the vehicle, whether by taking over the steering wheel or by pressing the brake pedal, a relevant takeover signal will be sent to the automatic driving system. After receiving the takeover signal, the automatic driving system will collect the steering information fed back by the steering gear and obtain the steering force from the steering information.

[0038] Step S120: The power steering system applies a resistance that decreases over time to the steering gear, causing the steering gear to release the steering force under the action of the resistance. The power steering system can be an electronic power steering system or a hydraulic power steering system; most vehicles currently use one of these two systems. Whether the steering wheel is released during manual driving or the driver takes over in autonomous driving mode, when the steering system removes the steering force applied to the steering column by controlling the power steering system, the steering column will quickly reverse under the action of the return force. Furthermore, during the takeover, the larger the steering angle, the greater the return force and the faster the reversal speed. Therefore, the vehicle body will sway laterally during the takeover. In this step, the resistance can be understood as a force in the same direction as the steering force that gradually decreases. Therefore, this resistance prevents the steering gear from immediately releasing the steering force applied during autonomous driving during the takeover. Instead, it gradually releases the steering force with the resistance, avoiding a sudden release of the steering force during the takeover, or a situation where the driver applies a counter-steering force while the steering force is being released, causing the steering column to quickly return to center under the action of the return force, resulting in a sudden lateral sway of the vehicle body.

[0039] In the steering control method for autonomous driving takeover in this embodiment, the steering gear releases the steering force under the aforementioned resistance, avoiding vehicle swaying and poor lateral stability caused by the sudden release of steering force. This steering control method for autonomous driving takeover in this embodiment is particularly suitable for situations where the autonomous vehicle takes over while turning. When the autonomous vehicle is traveling in a straight line, the method of this embodiment is not executed when taking over.

[0040] In step S120, the control assist system applies a resistance to the steering gear that decreases over time, including:

[0041] The initial resistance is initialized to the magnitude of the steering force, and its direction is the same as the steering force. That is, when taking over the steering gear, the initial resistance N0 is set as the steering force F. At the same time as the steering gear releases the steering force F, this initial resistance is applied to the steering gear by the power steering system.

[0042] Starting from time 0, the real-time resistance is calculated based on the relationship between the initial resistance and the preset resistance decreasing over time, and the power assist system is controlled to apply the real-time resistance to the steering gear.

[0043] It should be noted that the initial resistance applied by the power steering system can be the original steering force. In this step, the real-time resistance is calculated according to the relationship between the initial resistance and the preset resistance decreasing over time, and the power steering system is controlled to apply the real-time resistance to the steering gear. This power steering system can also be understood as an additional power steering system. For example, if the steering column is equipped with friction plates, in this step, the additional power steering system can be controlled to adjust the pressure on the friction plates to achieve the magnitude of the initial resistance and the real-time resistance.

[0044] In this embodiment, the relationship between the decrease in resistance and time can be expressed as follows:

[0045] N(t) = N0 - α·t

[0046] N0 = F

[0047] Where t is time, N(t) is real-time resistance, N0 is initial resistance, F is steering force, and α is a time coefficient, α>0. It can be seen that as time t increases, α·t increases, and the real-time resistance N(t) gradually decreases until it reaches 0, thus causing the steering force F to gradually decrease to 0, rather than suddenly decreasing to 0.

[0048] In practical applications, the lateral sway of a vehicle is related to the change in the vehicle's lateral acceleration. In order to more effectively suppress the lateral sway of the vehicle body, based on the above embodiment, the time coefficient α is associated with the vehicle's lateral acceleration A(t).

[0049] Another embodiment of the steering control method for automatic driving takeover of the present invention further includes: acquiring the lateral acceleration A(t) of the vehicle when the driver takes over, wherein the control assist system applies a resistance to the steering gear that decreases with time, including:

[0050] The initial resistance is initialized to the magnitude of the steering force, and its direction is the same as that of the steering force.

[0051] Starting from time 0, the real-time resistance is calculated based on the initial resistance, the lateral acceleration, and the preset relationship between the resistance and time, and the power assist system is controlled to apply the real-time resistance to the steering gear.

[0052] Specifically, α is designed to be a variable value that is inversely proportional to the magnitude of the real-time measured lateral acceleration A(t) of the vehicle body. The lateral acceleration changes with time t, and the inverse relationship is as follows:

[0053] α=β / |A(t)|

[0054] Intuitively, if the body sways more, the body is less stable, and α needs to be smaller so that the real-time resistance decreases more slowly over time, thus preventing the driver from oversteering.

[0055] Therefore, the relationship between resistance and time is:

[0056]

[0057] Where A(t) is the lateral acceleration, β is the proportionality coefficient, β>0, and || represents the absolute value operation.

[0058] In this embodiment, β satisfies 1<β<20. β is set according to the different vehicle conditions. For example, the smaller the mass of the vehicle, the smaller β is, because the smaller the mass of the vehicle, such as a sedan, the smaller the inertia. After the steering force is suddenly released, it is easier to sway laterally. That is, the larger A(t) is, the smaller β is, so that the real-time resistance changes less over time.

[0059] To better prevent lateral swaying of the vehicle, the method in this embodiment further includes: adjusting the β value in real time according to the change in lateral acceleration, so that the smaller the lateral acceleration, the larger the β value, and vice versa. That is, the β value in the above formula is not a constant value, but varies with the lateral acceleration of the vehicle. If the lateral acceleration A(t) of the vehicle is larger, the body sway amplitude is usually larger, the β value is smaller, and α is smaller, resulting in a smaller change in real-time resistance over time. Conversely, if the lateral acceleration A(t) of the vehicle is smaller, the body sway amplitude is usually smaller, the β value is larger, and α is larger, resulting in a larger change in real-time resistance over time.

[0060] The steering control device for automatic driving takeover provided by the present invention is described below. The steering control device for automatic driving takeover described below can be referred to in correspondence with the steering control method for automatic driving takeover described above.

[0061] like Figure 2 As shown, the steering control device for automatic driving takeover of the present invention includes:

[0062] Steering force acquisition module 210 is used to acquire the steering force applied to the steering column by the steering gear when the driver takes over.

[0063] The resistance application module 220 is used to control the power assist system to apply a resistance that decreases over time to the steering gear, so that the steering gear releases the steering force under the action of the resistance.

[0064] In this embodiment, when the autonomous driving system takes over, the steering control device releases the steering force under the aforementioned resistance, thus avoiding the problem of vehicle body swaying and poor lateral stability caused by the steering gear suddenly releasing the steering force or the driver applying a reverse steering force at the same time as releasing the steering force.

[0065] Optionally, the resistance application module 220 includes:

[0066] The resistance initialization module is used to initialize the initial resistance to the magnitude of the steering force, and the direction is the same as the steering force.

[0067] The real-time resistance application module is used to calculate the real-time resistance starting from time 0, based on the initial resistance and the preset relationship between the resistance and the decrease over time, and to control the power assist system to apply the real-time resistance to the steering gear.

[0068] Optionally, the relationship between the decrease in resistance and time is:

[0069] n(t) = N0 - α·t

[0070] N0 = F

[0071] Where t is time, N(t) is real-time resistance, N0 is initial resistance, F is steering force, α is time coefficient, and α>0.

[0072] Optionally, the steering control device for automatic driving takeover of the present invention further includes:

[0073] The lateral acceleration acquisition module is used to acquire the vehicle's lateral acceleration when the driver takes over.

[0074] The resistance application module 220 includes:

[0075] The resistance initialization module is used to initialize the initial resistance to the magnitude of the steering force, and the direction is the same as the steering force.

[0076] The real-time resistance application module is used to calculate the real-time resistance starting from time 0, based on the initial resistance, the lateral acceleration, and a preset formula for the relationship between the resistance and the decrease over time, and to control the power assist system to apply the real-time resistance to the steering gear.

[0077] Optionally, the relationship between the decrease in resistance and time is:

[0078]

[0079] Where A(t) is the lateral acceleration, β is the proportionality coefficient, β>0, and || represents the absolute value operation.

[0080] Optionally, β satisfies 1 < β < 20.

[0081] Optionally, the real-time resistance application module is also used to adjust the β value in real time according to the change in the lateral acceleration, so that the smaller the lateral acceleration, the larger the β value, and the larger the lateral acceleration, the smaller the β value.

[0082] Figure 3 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 3 As shown, the electronic device may include: a processor 310, a communication interface 320, a memory 330, and a communication bus 340, wherein the processor 310, the communication interface 320, and the memory 330 communicate with each other via the communication bus 340. The processor 310 can call logical instructions in the memory 330 to execute a steering control method during automatic driving takeover, the method including:

[0083] When the driver takes over, the steering force applied to the steering column by the steering gear is obtained.

[0084] The power steering system applies a resistance to the steering gear that decreases over time, so that the steering gear releases the steering force under the action of the resistance.

[0085] Furthermore, the logical instructions in the aforementioned memory 330 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0086] On the other hand, the present invention also provides a computer program product, the computer program product comprising a computer program that can be stored on a non-transitory computer-readable storage medium, wherein when the computer program is executed by a processor, the computer is able to execute the steering control method for automatic driving takeover provided by the above methods, the method comprising:

[0087] When the driver takes over, the steering force applied to the steering column by the steering gear is obtained.

[0088] The power steering system applies a resistance to the steering gear that decreases over time, so that the steering gear releases the steering force under the action of the resistance.

[0089] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to perform the steering control method for automatic driving takeover provided by the methods described above, the method comprising:

[0090] When the driver takes over, the steering force applied to the steering column by the steering gear is obtained.

[0091] The power steering system applies a resistance to the steering gear that decreases over time, so that the steering gear releases the steering force under the action of the resistance.

[0092] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0093] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A steering control method for automatic driving takeover, characterized in that, include: When the driver takes over, the steering force applied to the steering column by the steering gear is obtained; The power steering system applies a resistance that decreases over time to the steering gear, so that the steering gear releases the steering force under the action of the resistance; The method further includes: acquiring the lateral acceleration of the vehicle when the driver takes over, wherein the control assist system applies a time-decreasing resistance to the steering gear, including: The initial resistance is initialized to the magnitude of the steering force, and its direction is the same as that of the steering force; Starting from time 0, the real-time resistance is calculated based on the initial resistance, the lateral acceleration, and the preset relationship between the resistance and time. The power assist system is then controlled to apply the real-time resistance to the steering gear. The greater the lateral acceleration, the slower the real-time resistance decreases over time. The relationship between the decrease in resistance and time is: ； in, For time, For real-time resistance, As the initial resistance, For the lateral acceleration, This is the proportionality coefficient. | represents absolute value operation; The method further includes: adjusting the lateral acceleration in real time based on the change in lateral acceleration. The smaller the value, the smaller the lateral acceleration. The larger the value, the greater the lateral acceleration. The smaller the value.

2. The steering control method for automatic driving takeover according to claim 1, characterized in that, The β Satisfy 1< β <20.

3. A steering control device for automatic driving takeover, characterized in that, include: The steering force acquisition module is used to acquire the steering force applied to the steering column by the steering gear when the driver takes over. A resistance application module is used to control the power assist system to apply a resistance that decreases over time to the steering gear, so that the steering gear releases the steering force under the action of the resistance; The device further includes: a lateral acceleration acquisition module for acquiring the lateral acceleration of the vehicle when the driver takes over; The resistance application module includes: The resistance initialization module is used to initialize the initial resistance to the magnitude of the steering force, and the direction is the same as the steering force. The real-time resistance application module is used to calculate the real-time resistance starting from time 0, based on the initial resistance, the lateral acceleration, and a preset relationship between the resistance and the decrease over time, and to control the power assist system to apply the real-time resistance to the steering gear. The greater the lateral acceleration, the slower the real-time resistance decreases over time. The relationship between the decrease in resistance and time is: ； in, For time, For real-time resistance, As the initial resistance, For the lateral acceleration, This is the proportionality coefficient. | represents absolute value operation; The real-time resistance application module is also used to adjust the [something] in real time according to the change in lateral acceleration. The smaller the value, the smaller the lateral acceleration. The larger the value, the greater the lateral acceleration. The smaller the value.

4. An electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steering control method for automatic driving takeover as described in any one of claims 1 to 2.

5. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steering control method for automatic driving takeover as described in any one of claims 1 to 2.

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