Vehicle steering control method, device and vehicle

Abstract

The embodiment of the application relates to the technical field of vehicles, and discloses a vehicle steering control method, a vehicle steering control device and a vehicle, the vehicle steering control method comprising the following steps: determining a target steering style of a vehicle based on steering wheel angle information of the vehicle; determining a steering ratio of the vehicle based on the target steering style; determining a target steering angle of the vehicle based on driving state information of the vehicle and the steering ratio; and performing steering control on the vehicle based on the target steering angle. The steering wheel angle information is used to represent the rotation amplitude, rotation speed and rotation intensity of the steering wheel angle. The technical scheme provided by the embodiment of the application can improve the flexibility and accuracy of steering control and improve the driving experience of a user.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, specifically to a vehicle steering control method, device, and vehicle. Background Technology

[0002] Steering control equipment is a device that controls the steering of a vehicle.

[0003] In related technologies, steering control devices include mechanical steering devices, hydraulic steering devices, and steer-by-wire devices. The steering ratio of mechanical and hydraulic steering devices is limited by their mechanical structure, making them inflexible and difficult to adapt to different vehicle driving scenarios. Steer-by-wire devices offer a relatively simple method for adjusting the steering ratio, similarly failing to match actual vehicle driving conditions and thus unable to meet the driver's needs. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this application is to provide a vehicle steering control method, device and vehicle, which improves the flexibility and accuracy of steering control, thereby improving the user's driving experience.

[0005] In a first aspect, embodiments of this application provide a vehicle steering control method, the method comprising: determining a target steering style of the vehicle based on steering wheel angle information; determining a steering ratio of the vehicle based on the target steering style; determining a target steering angle of the vehicle based on the vehicle's driving state information and the steering ratio; and performing steering control on the vehicle based on the target steering angle. The steering wheel angle information is used to characterize the rotation amplitude, rotation speed, and degree of rotation intensity of the steering wheel angle.

[0006] The technical solution provided in this application determines the driver's steering style through steering wheel angle information, and then determines the steering ratio based on the steering style. Steering control based on the steering ratio determined by the steering style can better match the driver's driving habits and meet the driver's driving needs, resulting in a better user driving experience. Simultaneously, by combining driving state parameters and steering ratio to determine the target steering angle, compared to a simple one-to-one correspondence between steering ratio and steering angle, the obtained target steering angle is more accurate and more closely reflects actual vehicle driving scenarios.

[0007] One possible implementation method, which determines the vehicle's target steering style based on the vehicle's steering wheel angle information, can be specifically implemented as follows: based on the steering wheel angle information, a preset fuzzy rule algorithm is used to determine the target steering style. Here, the preset fuzzy rule algorithm represents the mapping relationship between the vehicle's steering wheel angle information and the vehicle's steering style.

[0008] The above technical solution determines the steering style through a preset fuzzy rule algorithm, which can integrate multiple features for fuzzy inference. It has strong scalability while the judgment result is not easily affected by noise, and the determined steering style is more stable and reliable. Moreover, the amount of data required for inference based on preset fuzzy rules is small, which can reduce the time and resources consumed in the calculation process.

[0009] One possible implementation involves a predefined fuzzy rule algorithm that specifies at least one range for reflecting the steering wheel angle's rotation amplitude, at least one range for reflecting the steering wheel angle's rotation speed, and at least one range for reflecting the steering wheel angle's rotation intensity. Based on the steering wheel angle information, the target steering style is determined using the predefined fuzzy rule algorithm. Specifically, this can be achieved by determining the target steering style based on the membership degrees of the rotation amplitude, rotation speed, and rotation intensity in each range, as well as the predefined fuzzy rules. Here, the predefined fuzzy rules represent the fuzzy correspondence between the combination of the rotation amplitude, rotation speed, and rotation intensity ranges in the predefined fuzzy rule algorithm and each steering style of the vehicle.

[0010] The above technical solution uses a membership function to characterize the strength of data belonging to different intervals, achieving a smooth transition in judgment and switching between different intervals, avoiding abrupt changes and misjudgments, and making the determined steering style more continuous and stable.

[0011] One possible implementation, determining the vehicle's steering ratio based on the target steering style, can be specifically implemented as follows: determining the steering ratio based on a first mapping relationship between the vehicle speed and the target steering style. Here, the first mapping relationship characterizes the correspondence between vehicle speed and vehicle steering ratio.

[0012] The above technical solution assigns different first mapping relationships to different steering styles, and then determines the steering ratio based on the corresponding first mapping relationship. The resulting steering ratio is more in line with the driver's driving habits and actual driving scenarios.

[0013] One possible implementation, determining the vehicle's steering ratio based on a target steering style, can be specifically implemented as follows: determining the vehicle's driving mode, and then determining the steering ratio based on a second mapping relationship between the vehicle speed, driving mode, and target steering style. The driving modes include parking mode and track mode. The second mapping relationship characterizes the correspondence between the combination of vehicle speed and driving mode and the vehicle's steering ratio. Under the same vehicle speed, the steering ratio corresponding to parking mode is higher than that corresponding to track mode.

[0014] The above technical solution allows for a higher vehicle steering ratio in parking mode compared to track mode, which reduces the number of steering wheel turns in parking mode while improving driving stability in track mode.

[0015] One possible implementation involves using driving status information including steering wheel angle and steering wheel speed. Determining the target steering angle based on the vehicle's driving status information and steering ratio can be specifically implemented as follows: determining the initial steering angle based on the steering wheel angle and steering ratio, determining the steering gain coefficient based on the steering wheel speed, and determining the target steering angle based on the steering gain coefficient and the initial steering angle. The steering gain coefficient is used to enhance the vehicle's steering response speed.

[0016] The above technical solution adjusts the initial steering angle by using a steering gain coefficient determined by the steering wheel rotation speed. The determined steering angle is more in line with the steering wheel angle change trend, which improves the vehicle's emergency steering response speed and enables it to pass ASIL-D safety certification.

[0017] One possible implementation is that the driving state information also includes yaw rate and / or lateral acceleration. Determining the target steering angle based on the steering gain coefficient and the initial steering angle can be specifically implemented as follows: determining a first steering angle based on the steering gain coefficient and the initial steering angle; determining the vehicle's feedback compensation steering angle based on the yaw rate and / or lateral acceleration; and determining the target steering angle based on the first steering angle and the feedback compensation steering angle.

[0018] The above technical solution adjusts the first steering angle based on the yaw rate and / or lateral acceleration, taking into account the vehicle's driving stability during steering, resulting in better vehicle stability and user experience.

[0019] One possible implementation is to determine the first steering angle based on the steering gain coefficient and the initial steering angle. Specifically, this can be achieved by multiplying the steering gain coefficient and the initial steering angle to determine the first steering angle.

[0020] One possible implementation is to determine the vehicle's feedback compensation steering angle based on the yaw rate, which can be specifically implemented as: determining the feedback compensation steering angle based on the deviation between the yaw rate and the target yaw rate.

[0021] The above technical solution uses the target yaw rate to adjust the steering angle, ensuring that the vehicle's yaw rate always follows the target yaw rate. This reduces the tracking error of the yaw rate in high-speed corners and enables it to pass ASIL-D safety certification.

[0022] One possible implementation, the vehicle steering control method provided in this application embodiment, further includes: when the target steering angle is greater than a preset steering angle safety threshold, updating the target steering angle to be less than or equal to the preset steering angle safety threshold, and performing vehicle steering control based on the updated target steering angle.

[0023] The above technical solution is updated and adjusted when the target steering angle is too high, so as to avoid safety hazards caused by oversteering.

[0024] One possible implementation, the vehicle steering control method provided in this application embodiment, further includes: in the event of a failure to perceive steering wheel angle information and / or driving status information, performing steering control on the vehicle according to the most recently determined target steering angle. After the completion time of performing steering control on the vehicle according to the most recently determined target steering angle reaches a preset time, controlling the vehicle's wheels to return to center at a preset return rate.

[0025] The above technical solution, in the event of a communication failure, uses the most recently determined target steering angle for steering control and automatically returns the wheels to center, thus avoiding steering control failure and continuous steering issues in the event of a communication failure.

[0026] One possible implementation is to represent the rotation amplitude in the steering wheel angle information using the standard deviation of the steering wheel angle within the sliding window. The rotation speed in the steering wheel angle information is represented by the peak angular velocity of the steering wheel within the sliding window. The intensity of the rotation in the steering wheel angle information is represented by the mean angular acceleration of the steering wheel within the sliding window.

[0027] Secondly, this application provides a vehicle steering control device, including a processing module and a control module.

[0028] The aforementioned processing module is used to determine the vehicle's target steering style based on the vehicle's steering wheel angle information.

[0029] The aforementioned processing module is also used to determine the vehicle's steering ratio based on the target steering style.

[0030] The aforementioned processing module is also used to determine the target steering angle of the vehicle based on the vehicle's driving status information and steering ratio.

[0031] The aforementioned control module is used to control the vehicle's steering based on the target steering angle.

[0032] Among them, the steering wheel angle information is used to characterize the steering wheel angle's rotation amplitude, rotation speed, and degree of rotation intensity.

[0033] One possible implementation is that the aforementioned processing module is specifically used to: determine the target steering style based on the steering wheel angle information using a preset fuzzy rule algorithm. The preset fuzzy rule algorithm represents the mapping relationship between the vehicle's steering wheel angle information and its steering style.

[0034] One possible implementation involves a predefined fuzzy rule algorithm that specifies at least one range for reflecting the steering wheel angle's rotation amplitude, at least one range for reflecting the steering wheel angle's rotation speed, and at least one range for reflecting the steering wheel angle's rotation intensity. Specifically, the processing module is used to: determine the target steering style based on the membership degrees of the rotation amplitude, rotation speed, and rotation intensity in each range and the predefined fuzzy rules. The predefined fuzzy rules characterize the fuzzy correspondence between the combination of the rotation amplitude, rotation speed, and rotation intensity ranges in the predefined fuzzy rule algorithm and each steering style of the vehicle.

[0035] One possible implementation is that the aforementioned processing module is specifically used to: determine the steering ratio based on a first mapping relationship between the vehicle speed and the target steering style. The first mapping relationship characterizes the correspondence between vehicle speed and vehicle steering ratio.

[0036] One possible implementation is that the aforementioned processing module is specifically used to: determine the vehicle's driving mode, and determine the steering ratio based on a second mapping relationship corresponding to the vehicle speed, driving mode, and target steering style. The driving modes include parking mode and track mode. The second mapping relationship characterizes the correspondence between the combination of vehicle speed and driving mode and the vehicle steering ratio. In the second mapping relationship, when the vehicle speed is the same, the steering ratio corresponding to parking mode is higher than that corresponding to track mode.

[0037] One possible implementation involves using steering wheel angle and steering wheel speed as the driving status information. Specifically, the aforementioned processing module is used to: determine the initial steering angle of the vehicle based on the steering wheel angle and steering ratio; determine the vehicle's steering gain coefficient based on the steering wheel speed; and determine the target steering angle based on the steering gain coefficient and the initial steering angle. The steering gain coefficient is used to enhance the vehicle's steering response speed.

[0038] One possible implementation is that the driving state information further includes yaw rate and / or lateral acceleration. Specifically, the aforementioned processing module is used to: determine a first steering angle based on the steering gain coefficient and the initial steering angle; determine the vehicle's feedback compensation steering angle based on the yaw rate and / or lateral acceleration; and determine a target steering angle based on the first steering angle and the feedback compensation steering angle.

[0039] One possible implementation is that the above processing module is specifically used to: determine the steering gain coefficient and the initial steering angle as the first steering angle.

[0040] One possible implementation is that the aforementioned processing module is specifically used to: determine the feedback compensation steering angle based on the deviation between the yaw rate and the target yaw rate.

[0041] In one possible implementation, the processing module is further configured to: update the target steering angle to be less than or equal to the preset steering angle safety threshold when the target steering angle is greater than the preset steering angle safety threshold. The control module is further configured to: perform vehicle steering control based on the updated target steering angle.

[0042] In one possible implementation, the control module is further configured to: control the vehicle's steering according to the most recently determined target steering angle when the perception of steering wheel angle information and / or driving status information fails; and after the completion time of steering control according to the most recently determined target steering angle reaches a preset duration, control the vehicle's wheels to return to center at a preset return rate.

[0043] One possible implementation is to represent the rotation amplitude in the steering wheel angle information using the standard deviation of the steering wheel angle within the sliding window. The rotation speed in the steering wheel angle information is represented by the peak angular velocity of the steering wheel within the sliding window. The intensity of the rotation in the steering wheel angle information is represented by the mean angular acceleration of the steering wheel within the sliding window.

[0044] The technical effects of any implementation method in the second aspect can be found in the technical effects of any implementation method in the first aspect mentioned above, and will not be repeated here.

[0045] Thirdly, this application provides a vehicle. The vehicle includes the vehicle steering control device in any embodiment of the second aspect described above, or the vehicle implements steering control using the vehicle steering control method in any embodiment of the first aspect described above.

[0046] Fourthly, this application provides a computer-readable storage medium storing at least one computer program, which is loaded and executed by a processor to implement the vehicle steering control method in any of the embodiments of the first aspect described above.

[0047] Fifthly, this application provides a computer program product, which includes a computer program or instructions that, when executed by a processor, implement the vehicle steering control method in any of the embodiments of the first aspect described above.

[0048] The solutions provided in the third to fifth aspects above can realize the vehicle steering control method in any embodiment of the first aspect above, and their specific implementations will not be described in detail here. The technical effects corresponding to any implementation of the solutions provided in the third to fifth aspects above can be found in the technical effects corresponding to any implementation of the first aspect above, and will not be described in detail here.

[0049] It should be noted that any of the possible implementations of any of the above aspects can be combined, provided that the solutions do not contradict each other. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the embodiments of this application or the background art, the accompanying drawings used in the embodiments of this application will be described below.

[0051] Figure 1 This is a schematic diagram of the structure of a steering control device disclosed in an embodiment of this application; Figure 2 This is a schematic flowchart of a vehicle steering control method disclosed in an embodiment of this application; Figure 3 This is a schematic diagram of the architecture of another vehicle steering control method disclosed in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of a vehicle steering control device disclosed in an embodiment of this application.

[0052] Explanation of reference numerals in the attached figures: 100 - Sensor; 200 - Controller; 300 - Steering motor. Detailed Implementation

[0053] To enable those skilled in the art to better understand the technical solutions of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0054] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0055] In the embodiments of this application, the words "exemplary," "for example," or "e.g.," are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplary," "for example," or "e.g.," in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the words "exemplary," "for example," or "e.g.," is intended to present the relevant concepts in a specific manner.

[0056] The embodiments of this application are described below with reference to the accompanying drawings.

[0057] This application provides a vehicle.

[0058] Alternatively, a vehicle may also be referred to as a vehicle, mobile carrier, electric vehicle (EV), hybrid electric vehicle (HEV), plug-in hybrid electric vehicle (PHEV), fuel cell vehicle (FCV), autonomous vehicle, intelligent and connected vehicle (ICV), driverless vehicle, new energy vehicle, etc.

[0059] In this application's embodiments, the vehicle can be a sedan, a sport utility vehicle (SUV), a truck, an electric vehicle, a motorcycle, a tricycle, a special vehicle (such as an ambulance, fire truck, police car, etc.), a driverless taxi, an intelligent connected bus, an autonomous logistics vehicle, an electric truck, etc. The method provided in this application's embodiments is also applicable to various special-purpose vehicles, such as agricultural vehicles, mining vehicles, forestry vehicles, airport vehicles, port vehicles, etc., and this application does not impose specific limitations on them. For example, the vehicle can be an electric sport utility vehicle (SUV) including a hub motor, kingpin steering, fully active air suspension, and EMB.

[0060] In some embodiments, the vehicle includes a steering control device. The steering control device is a device that controls the steering of the vehicle.

[0061] Optionally, steering control equipment includes mechanical steering equipment (such as steering column, steering gear and steering transmission mechanism), hydraulic steering equipment (such as hydraulic pump, oil pipe, control valve and hydraulic cylinder) and steer-by-wire equipment (such as sensor, controller and steering motor).

[0062] Among them, the steering ratio (the ratio of the steering wheel rotation angle to the wheel rotation angle) of mechanical and hydraulic steering systems is limited by their mechanical structure and cannot be flexibly adjusted. This makes it difficult to balance the agility of the vehicle at low speeds with the stability at high speeds. For example, in low-speed parking scenarios, a high steering ratio requires more steering wheel rotations compared to a low steering ratio, making it less flexible and convenient. While the steering ratio of steer-by-wire systems can be preset, the adjustment method is relatively simple (e.g., determining the steering ratio solely based on vehicle speed), making it difficult to adapt to actual driving scenarios and the driver's needs.

[0063] Based on this, embodiments of this application provide a vehicle steering control method and apparatus that can improve the flexibility and accuracy of steering control, thereby enhancing the user's driving experience. The method can be applied to, for example... Figure 1 The rotation control device shown, or applied to other devices capable of achieving steering control functions.

[0064] For example, please refer to Figure 1 , Figure 1 This is a schematic diagram of a steering control device provided in an embodiment of this application. The steering control device provided in this embodiment includes a sensor 100, a controller 200, and a steering motor 300.

[0065] Among them, sensor 100 is used to collect steering wheel angle information such as steering wheel angle amplitude and rotation speed, and also to collect vehicle driving status information such as vehicle speed, yaw rate, and lateral acceleration. For example: Figure 3 As shown, the input layer (including sensors) acquires steering wheel angle information, driving status information, and driving mode.

[0066] Optionally, sensor 100 includes an angle sensor, a torque sensor, a speed sensor, etc.

[0067] The controller 200 is used to determine the target steering angle of the vehicle based on steering wheel angle information and driving status information. For example: Figure 3As shown, the target steering style is determined based on a preset fuzzy rule algorithm and the steering wheel angle information from the input layer. Further, the control layer (including the controller) determines the initial steering angle based on the target steering style, and adjusts the initial steering angle based on the steering wheel rotation speed and yaw rate to obtain the target steering angle. Optionally, the controller 200 includes an electronic control unit (ECU), a domain controller (DCU), a microcontroller unit (MCU), etc.

[0068] For example, controller 200 includes a main controller and a backup controller, wherein steering control is performed by the backup controller in the event of a failure of the main controller.

[0069] The steering motor 300 is used to control the vehicle wheels to steer according to the target steering angle. For example: Figure 3 As shown, the execution layer (including the steering motor) controls the vehicle's wheel steering based on the target steering angle calculated by the control layer. For example, the steering motor 300 is a dual-winding steering motor, with both windings working together to output greater torque and higher power density. Furthermore, if one winding fails, steering control is achieved through the other winding, ensuring uninterrupted steering function.

[0070] For example, please refer to Figure 2 The vehicle steering control method provided in this application includes: Step S201: The steering control device determines the target steering style of the vehicle based on the vehicle's steering wheel angle information.

[0071] Target steering style characterizes a driver's steering preferences and habits when steering the vehicle. For example, the faster a driver turns the steering wheel, the more aggressive their steering style.

[0072] Optionally, the driver's steering style can be aggressive, smooth, or hesitant.

[0073] Steering wheel angle information is used to characterize the steering wheel's rotation amplitude, rotation speed, and intensity.

[0074] For example, the rotation amplitude in the steering wheel angle information is represented by the standard deviation of the steering wheel angle within a sliding window (e.g., a 2.5-second sliding time window). The rotation speed in the steering wheel angle information is represented by the peak value of the steering wheel's angular velocity within the sliding window. The intensity of the rotation in the steering wheel angle information is represented by the mean value of the steering wheel's angular acceleration within the sliding window.

[0075] For example, within a 2.5-second sliding time window (corresponding to 250 data points), the corner... Perform a first-order difference to obtain the angular velocity. =( - 100*, unit: degrees / second. Angular velocity. By performing a first-order difference, the angular acceleration is obtained. (i)=( - *100, unit: degrees / second². Based on the turning angle. Calculate the average angle Then, the standard deviation of the steering wheel angle is calculated based on the average steering angle. The calculation formula is as follows:

[0076]

[0077] in, Indicates the first There are N data points, where N represents the number of data points. Indicates the first The corner of each data point This represents the average angle. This represents the standard deviation of the steering wheel angle.

[0078] Peak angular velocity and mean angular acceleration The calculation formula is expressed as:

[0079]

[0080] in, Indicates the peak angular velocity. Indicates the first angular velocity of each data point This represents the mean angular acceleration, and N represents the number of data points. Indicates the first Angular acceleration of each data point.

[0081] In some embodiments, a preset fuzzy rule algorithm is used to determine the target steering style based on steering wheel angle information.

[0082] The preset fuzzy rule algorithm represents the mapping relationship between vehicle steering wheel angle information and vehicle steering style. The preset fuzzy rule algorithm is an algorithm that performs inference through preset fuzzy rules. Specifically, precise input quantities (such as peak angular velocity) are transformed into fuzzy quantities (such as fast or slow), and then the fuzzy quantities are inferred according to the preset fuzzy rules to obtain fuzzy outputs (such as aggressive or smooth). Finally, the precise output (such as the target steering style) is determined based on the fuzzy output.

[0083] For example, the preset fuzzy rule algorithm defines at least one rotation amplitude range to reflect the rotation amplitude of the steering wheel angle, at least one rotation speed range to reflect the rotation speed of the steering wheel angle, and at least one rotation intensity range to reflect the intensity of the steering wheel angle rotation. Based on the membership degree of the rotation amplitude in each rotation amplitude range, the membership degree of the rotation speed in each rotation speed range, the membership degree of the rotation intensity in each rotation intensity range, and the preset fuzzy rules, the target steering style is determined.

[0084] Among them, the preset fuzzy rule represents the fuzzy correspondence between the combination of rotation amplitude range, rotation speed range, and rotation intensity range in the preset fuzzy rule algorithm and each steering style of the vehicle.

[0085] For example, the rotation amplitude range includes "small", "medium", and "large", with a universe of discourse of [0, 5]. The membership function for "small" is: small = trimf(x; 0, 0, 10), for "medium" it is: medium = trimf(x; 5, 12.5, 20), and for "large" it is: large = trimf(x; 15; 25; 25). The rotation speed range includes "slow", "medium", and "fast", with a universe of discourse of [0, 200]. The membership function for "slow" is: slow = trimf(x; 0, 0, 80), for "medium" it is: medium = trimf(x; 50, 100, 150), and for "fast" it is: fast = trimf(x; 120, 200, 200). The intensity range of rotation includes "slow", "moderate" and "rapid". The domain of rotation intensity range is [0, 150]. The membership function corresponding to "slow" is: slow = trimf(x; 0, 0, 60), the membership function corresponding to "moderate" is: moderate = trimf(x; 30, 75, 120), and the membership function corresponding to "rapid" is: rapid = trimf(x; 90, 150, 150).

[0086] Calculated using membership function Membership degree in each rotation range Membership degree in each rotational speed range and Membership degree in each range of rotation intensity. For example: in =18, =165, In the case of =110, The membership degree of belonging to large (L) is 0.6, and the membership degree of belonging to medium (M) is 0.4. The membership degree of Fast is 0.9, and the membership degree of Medium is 0.1. The membership degree for Abrupt is 0.67, and the membership degree for Moderate is 0.33.

[0087] Then, according to Membership degree in each rotation range Membership degree in each rotational speed range The membership degree and preset fuzzy rules in each range of rotation intensity are used to determine... =18, =165, The trigger strength of each preset fuzzy rule when the value is 110. The preset fuzzy rules are shown in Table 1, but are not limited to this.

[0088] Table 1: Preset Fuzzy Rules

[0089] For example: in =18, =165, When the value is 110, Rule1 and Rule2 are the main triggers. The minimum value of the trigger strength zone membership of Rule1 and Rule2 is min(0.6, 0.9, 0.67) = 0.6, and the trigger strength of Rule2 is min(0.6, 0.9, 0.33) = 0.33.

[0090] Next, based on the trigger strength of each preset fuzzy rule, the steering style index is calculated using methods such as the centroid method, area center method, or maximum value averaging method. The target steering style is then determined based on the steering style index. For example, the universe of discourse for the steering style index (SI) is a continuous value [0, 10]. The membership function corresponding to a stationary steering style is: Calm = trimf(SI, 0, 0, 4); the membership function corresponding to a hesitant steering style is: Hesitant = trimf(SI; 2, 5, 8); and the membership function corresponding to an aggressive steering style is: Aggressive = trimf(SI; 6, 10, 10). Using the centroid method, the inference results (trigger strengths) of Rule 1 and Rule 2 are aggregated, resulting in a steering style index SI = 7.8. When the steering style index SI ∈ [0, 3.5], the target steering style is stationary. When the steering style index SI ∈ (3.5, 6.5), the target steering style is hesitant. When the steering style index SI ∈ [6.5, 10], the target steering style is aggressive. Therefore, when the steering style index SI = 7.8, the target steering style is determined to be aggressive.

[0091] Step S202: The steering control device determines the vehicle's steering ratio based on the target steering style.

[0092] Steering ratio is the ratio of the steering wheel rotation angle to the vehicle's wheel rotation angle. With the same wheel rotation angle, a larger steering ratio requires a larger steering wheel rotation angle. Therefore, a larger steering ratio makes the vehicle more stable during steering and less prone to veering off course at high speeds. A smaller steering ratio makes steering control more flexible and precise, and is more suitable for low-speed driving scenarios such as maneuvering and U-turns.

[0093] For example, the steering ratio is determined based on a first mapping relationship between the vehicle speed and the target steering style.

[0094] The first mapping relationship is used to characterize the correspondence between vehicle speed and vehicle steering ratio. Different steering styles correspond to different first mapping relationships, in order to determine a steering ratio that better suits the driver's steering habits and improves the driver's driving experience.

[0095] For example, the driving mode of the vehicle is determined, and the steering ratio is determined based on a second mapping relationship between the vehicle speed, driving mode, and target steering style.

[0096] The second mapping relationship characterizes the correspondence between the combination of vehicle speed and driving mode and the vehicle steering ratio. Different steering styles correspond to different second mapping relationships.

[0097] Optionally, driving modes include: parking mode, track mode, and snow / ice mode. Driving modes can be manually set by the driver, such as by receiving a mode selection command from the driver, or they can be automatically switched based on driving status parameters, such as automatically switching to parking mode when the vehicle speed is less than 5 km / h and the gear is in reverse (R).

[0098] In the second mapping relationship, under the same vehicle speed, the steering ratio corresponding to parking mode is higher than that corresponding to track mode. For example, the steering ratio K_park ≥ 20 in parking mode, while the steering ratio 8 ≤ K_track ≤ 10 in track mode. Determining the steering ratio based on the driving mode reduces the number of steering wheel turns in low-speed parking scenarios, making it easier for the driver to operate. In icy and snowy road conditions, a lower steering ratio reduces the risk of oversteer, balancing handling agility, stability, and the driver's individual needs.

[0099] Step S203: The steering control device determines the target steering angle of the vehicle based on the vehicle's driving status information and steering ratio.

[0100] Optionally, the driving status information includes steering wheel angle, steering wheel speed, yaw rate, and lateral acceleration.

[0101] In some embodiments, the initial steering angle of the vehicle is determined based on the steering wheel angle and steering ratio, and the steering gain coefficient of the vehicle is determined based on the steering wheel rotation speed. The target steering angle is then determined based on the steering gain coefficient and the initial steering angle.

[0102] The initial steering angle is the product of the steering wheel angle and the reciprocal of the steering ratio. For example, if the steering wheel angle is 120° and the steering ratio is 10:1, then the initial steering angle is 12°.

[0103] Steering gain coefficient is used to enhance the steering response speed of a vehicle. When the steering wheel is continuously turned, adjusting the initial steering angle according to the steering wheel rotation speed ensures that the initial steering angle follows changes in the steering wheel angle promptly, avoiding problems such as the initial steering angle failing to match the actual steering wheel angle due to excessive steering wheel rotation speed or communication delays. For example, the steering gain coefficient K_ω = 1 + k·|ω|, where k represents the preset calibration coefficient and ω represents the steering wheel rotation speed.

[0104] Furthermore, when |ω| is lower than the first preset threshold ω1, K_ω=1. When |ω| is higher than the second preset threshold ω2, the maximum value of K_ω is K_max (1.5≤K_max≤2.5). When ω1<|ω|<ω2, K_ω=1+k(|ω|-ω1).

[0105] For example, a first steering angle is determined based on the steering gain coefficient and the initial steering angle. A feedback-compensated steering angle is determined based on the yaw rate and / or lateral acceleration. A target steering angle is determined based on the first steering angle and the feedback-compensated steering angle.

[0106] For example, the product of the steering gain coefficient and the initial steering angle is determined as the first steering angle. The formula for calculating the first steering angle is: δ_temp = δ_base × K_ω, where K_ω represents the steering gain coefficient, δ_base represents the initial steering angle, and δ_temp represents the first steering angle.

[0107] For example, the feedback compensation steering angle is determined based on the deviation between the yaw rate and the target yaw rate. For instance, the yaw rate and the target yaw rate are input into a closed-loop controller, such as a proportional-integral-derivative (PID) controller. The PID controller outputs the feedback compensation steering angle Δδ = Kp·Δγ + Ki·∫Δγdt + Kd·d(Δγ) / dt, where Δγ = γ_target - γ_actual, γ_target represents the target yaw rate, and γ_actual represents the yaw rate.

[0108] The formula for calculating γ_target is as follows:

[0109]

[0110] in, Indicates the target's yaw rate. Indicates the vehicle's longitudinal speed. Indicates the vehicle's wheelbase. K represents the front wheel steering angle, K represents the stability factor, and m represents the mass. This indicates the lateral stiffness of the rear wheel. This indicates the lateral stiffness of the front wheel. This indicates the distance between the vehicle's center of gravity and the front axle. This indicates the distance between the vehicle's center of gravity and the rear axle.

[0111] In some embodiments, if the main controller for determining the target steering angle fails, the target steering angle is determined by a backup controller.

[0112] For example, if the main controller that determines the target steering angle fails, the backup controller determines the target steering angle using a preset vehicle speed-steering ratio mapping relationship or vehicle speed-steering angle mapping relationship.

[0113] Step S204: The steering control device performs steering control on the vehicle based on the target steering angle.

[0114] For example, a dual-winding steering motor receives a target steering angle and drives the wheels to steer to the target steering angle.

[0115] In some embodiments, if the target steering angle is greater than a preset steering angle safety threshold, the target steering angle is updated to be less than or equal to the preset steering angle safety threshold, and vehicle steering control is performed based on the updated target steering angle. For example, if the target steering angle is greater than the preset steering angle safety threshold, the target steering angle is updated to a safe steering angle δ_safe = δ_max·sign(θ). Here, δ_max represents the preset steering angle safety threshold, and θ represents the target steering angle. Another example is... Figure 3 As shown, the safety monitoring layer performs fault detection. When the target steering angle is greater than the preset steering angle safety threshold, it outputs a safe steering angle to the steering motor so that the steering motor controls the vehicle's wheel steering according to the safe steering angle.

[0116] In some embodiments, if the steering wheel angle information and / or driving status information sensing fails, the vehicle is steering controlled according to the most recently determined target steering angle. After a preset time has elapsed since the vehicle steering control according to the most recently determined target steering angle was completed, the vehicle wheels are controlled to return to center at a preset return rate.

[0117] For example, in the event of a communication failure between the controller and the sensor, the vehicle is steering controlled based on the latest target steering angle stored locally by the controller.

[0118] For example, if the communication time between the controller and the sensor exceeds the preset communication time, the target steering angle is determined as δ_safe=c·v·θ, where c represents the preset proportional coefficient, v represents the vehicle speed, and θ represents the steering wheel angle.

[0119] As an example, vehicle steering control methods in high-speed emergency obstacle avoidance scenarios include: Step S401: Obtain driving status parameters.

[0120] For example, the steering wheel angle θ: 120°, the vehicle speed v: 100km / h, the steering wheel rotation speed ω: 400° / s, the yaw rate γ: 15° / s, and the target yaw rate 12° / s.

[0121] Step S402: Calculate the initial steering angle.

[0122] For example, by querying the first mapping table between vehicle speed and steering ratio, the steering ratio is determined to be 10:1 when v=100km / h, and then the initial steering angle is calculated to be 12°.

[0123] Step S403: Calculate the first steering angle.

[0124] For example, the steering gain coefficient (preset k=0.002) calculated based on ω=400° / s is K_ω=1+0.002×|400|=1.8. Based on the steering gain coefficient and the initial steering angle, the first steering angle δ_temp=δ_base×K_ω=12°×1.8=21.6° is calculated. Compared with the traditional steering scheme (directly outputting 12°), the response delay of steering control is reduced.

[0125] Step S404: Calculate the target turning angle.

[0126] For example, the yaw rate deviation Δγ = 12° / s - 15° / s = -3° / s (oversteer), the feedback compensation steering angle output by the PID controller (proportional coefficient Kp = 0.5) Δδ = Kp × Δγ = 0.5 × (-3°) = -1.5°, then the target steering angle δ_final = δ_temp + Δδ = 21.6° - 1.5° = 20.1°, which suppresses the risk of oversteer and reduces the vehicle's sideslip.

[0127] Step S405: δ_final = 20.1°, which does not exceed the preset steering angle safety threshold of 25°. Control wheel steering based on 20.1°.

[0128] In some embodiments, in the event of a main controller failure, a fixed steering ratio of 10:1 is determined using a pre-stored calibration mapping relationship at v=100km / h, and the target steering angle at this time is determined to be 130° (current steering wheel angle) / 10=13°. The wheel angle is then adjusted from 20.1° to 13° at a gradual rate of 10° / s to avoid sudden steering changes.

[0129] Through experiments, the technical solution provided in this application, compared with the traditional technical solution that relies solely on vehicle speed to determine the steering ratio, has the technical effects shown in Table 2: Table 2

[0130] This application also provides a vehicle steering control device; please refer to [link / reference]. Figure 4 This application provides a vehicle steering control device including a processing module 401 and a control module 402. The processing module 401 is used to execute... Figure 2The operations of steps S201, S202, and S203 in the illustrated method are executed by the control module 402. Figure 2 The illustrated method includes step S204.

[0131] The foregoing mainly describes the solutions provided by the embodiments of this application from the perspective of methods and apparatus. To achieve the above functions, the vehicle steering control device includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily recognize that, in conjunction with the units and algorithm steps of the various examples described in the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0132] This application embodiment can, based on the above-described vehicle steering control method, exemplarily divide the vehicle steering control device into functional modules. For example, the vehicle steering control device may include functional modules corresponding to each functional division, or two or more functions may be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. It should be noted that the module division in this application embodiment is illustrative and only represents one logical functional division; in actual implementation, there may be other division methods.

[0133] This application also provides a computer-readable storage medium storing at least one computer program, which is loaded and executed by a processor to implement the vehicle steering control method provided in the above-described method embodiments.

[0134] Optionally, the computer-readable storage medium may be a non-transitory computer-readable storage medium, such as a read-only memory (ROM), random access memory (RAM), magnetic tape, floppy disk, and optical data storage device.

[0135] This application also provides a computer program product, which includes a computer program or instructions. When the computer program or instructions are executed by a processor, they implement the vehicle steering control method provided in the above-described method embodiments.

[0136] It should be noted that when one or more instructions in the computer-readable storage medium or computer program product are executed by the processor of a computing device, they implement the various processes of the above-described method embodiments and achieve the same technical effects as the above-described methods. To avoid repetition, they will not be described again here.

[0137] Through the above description of the embodiments, those skilled in the art can clearly understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0138] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another apparatus, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0139] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0140] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solutions of the embodiments of this application, essentially, or the parts that contribute to the prior art, or all or part of the technical solutions, can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0141] It should be understood that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims. Those skilled in the art can understand that implementing all or part of the processes of the above embodiments and making equivalent changes according to the claims of this application still fall within the scope of this application.

Claims

1. A vehicle steering control method, characterized in that, The vehicle steering control method includes: Based on the vehicle's steering wheel angle information, the target steering style of the vehicle is determined; wherein, the steering wheel angle information is used to characterize the steering wheel angle's rotation amplitude, rotation speed, and degree of rotation intensity. Based on the target steering style, the steering ratio of the vehicle is determined; Based on the vehicle's driving status information and the steering ratio, the target steering angle of the vehicle is determined; Based on the target steering angle, the vehicle is steering controlled.

2. The vehicle steering control method according to claim 1, characterized in that, The determination of the target steering style of the vehicle based on the vehicle's steering wheel angle information includes: Based on the steering wheel angle information, a preset fuzzy rule algorithm is used to determine the target steering style; The preset fuzzy rule algorithm represents the mapping relationship between vehicle steering wheel angle information and vehicle steering style.

3. The vehicle steering control method according to claim 2, characterized in that, The preset fuzzy rule algorithm specifies at least one rotation amplitude range for reflecting the rotation amplitude of the steering wheel angle, at least one rotation speed range for reflecting the rotation speed of the steering wheel angle, and at least one rotation intensity range for reflecting the rotation intensity of the steering wheel angle. The step of determining the target steering style based on the steering wheel angle information using a preset fuzzy rule algorithm includes: The target steering style is determined based on the membership degree of the rotation amplitude in each rotation amplitude interval, the membership degree of the rotation speed in each rotation speed interval, the membership degree of the rotation intensity in each rotation intensity interval, and a preset fuzzy rule. The preset fuzzy rule represents the fuzzy correspondence between the combination of the rotation amplitude range, the rotation speed range, and the rotation intensity range in the preset fuzzy rule algorithm and each steering style of the vehicle.

4. The vehicle steering control method according to any one of claims 1-3, characterized in that, Determining the vehicle's steering ratio based on the target steering style includes: The steering ratio is determined based on a first mapping relationship between the vehicle speed and the target steering style; wherein the first mapping relationship is used to characterize the correspondence between vehicle speed and vehicle steering ratio.

5. The vehicle steering control method according to any one of claims 1-3, characterized in that, Determining the vehicle's steering ratio based on the target steering style includes: Determine the driving mode of the vehicle, wherein the driving mode includes: parking mode and track mode; The steering ratio is determined based on a second mapping relationship between the vehicle speed, the driving mode, and the target steering style; wherein the second mapping relationship is used to characterize the correspondence between the combination of vehicle speed and vehicle driving mode and the vehicle steering ratio; in the second mapping relationship, when the vehicle speed is the same, the vehicle steering ratio corresponding to the parking mode is higher than the vehicle steering ratio corresponding to the track mode.

6. The vehicle steering control method according to any one of claims 1-3, characterized in that, The driving status information includes: steering wheel angle and steering wheel speed; Determining the target steering angle of the vehicle based on the vehicle's driving status information and the steering ratio includes: Based on the steering wheel angle and the steering ratio, the initial steering angle of the vehicle is determined; Based on the steering wheel rotation speed, the steering gain coefficient of the vehicle is determined; wherein, the steering gain coefficient is used to enhance the steering response speed of the vehicle; The target steering angle is determined based on the steering gain coefficient and the initial steering angle.

7. The vehicle steering control method according to claim 6, characterized in that, The driving status information also includes: yaw rate and / or lateral acceleration; Determining the target steering angle based on the steering gain coefficient and the initial steering angle includes: The first steering angle is determined based on the steering gain coefficient and the initial steering angle; The feedback compensation steering angle of the vehicle is determined based on the yaw rate and / or the lateral acceleration. The target steering angle is determined based on the first steering angle and the feedback compensation steering angle.

8. The vehicle steering control method according to claim 7, characterized in that, Determining the first steering angle based on the steering gain coefficient and the initial steering angle includes: The product of the steering gain coefficient and the initial steering angle is determined as the first steering angle; And, based on the yaw rate, determining the feedback compensation steering angle of the vehicle includes: The feedback compensation steering angle is determined based on the deviation between the yaw rate and the target yaw rate.

9. The vehicle steering control method according to claim 7, characterized in that, The vehicle steering control method further includes: If the target steering angle is greater than a preset steering angle safety threshold, the target steering angle is updated to be less than or equal to the preset steering angle safety threshold. The vehicle is steering controlled based on the updated target steering angle.

10. The vehicle steering control method according to claim 7, characterized in that, The vehicle steering control method further includes: If the steering wheel angle information and / or the driving status information fail to be perceived, the vehicle shall be steering controlled according to the most recently determined target steering angle; And, after the completion time of steering control of the vehicle according to the most recently determined target steering angle reaches a preset time, the wheels of the vehicle are controlled to return to center at a preset return rate. The rotation amplitude in the steering wheel angle information is represented by the standard deviation of the steering wheel angle within a sliding window; The rotation speed in the steering wheel angle information is represented by the peak angular velocity of the steering wheel within the sliding window; The degree of rotation intensity in the steering wheel angle information is represented by the average angular acceleration of the steering wheel within the sliding window.

11. A vehicle steering control device, characterized in that, include: The processing module is used to determine the target steering style of the vehicle based on the vehicle's steering wheel angle information; wherein the steering wheel angle information is used to characterize the steering wheel angle's rotation amplitude, rotation speed, and degree of rotation intensity. The processing module is also used to determine the steering ratio of the vehicle based on the target steering style; The processing module is also used to determine the target steering angle of the vehicle based on the vehicle's driving status information and the steering ratio; The control module is used to perform steering control on the vehicle based on the target steering angle.

12. A vehicle, characterized in that, Includes the vehicle control device as described in claim 11.

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