Vehicle steering control method and system, automatic driving equipment and readable storage medium
By dividing the driving path into multiple segments and calculating the direction vector to correct the vehicle's front wheel speed, the problem of inconsistent vehicle speed during high curvature steering is solved, and the effect of smooth driving and reducing jitter is achieved.
Patent Information
- Application Number
- CN202411918906.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-23
- Publication Date
- 2025-03-14
AI Technical Summary
In the high curvature steering scenario, the actual speed of the vehicle is inconsistent with the planned speed direction, resulting in large shaking of the vehicle body and affecting the driving experience.
By determining the starting point and ending point of the bend in the planned driving path, the driving path is divided into multiple segments, the direction vector of each segment path is calculated, and the vehicle's front wheel speed is determined based on the direction vector, and finally the vehicle's acceleration is controlled based on the vehicle speed to drive smoothly.
The actual vehicle speed is consistent with the planned speed, which reduces the sudden acceleration and deceleration of the vehicle, reduces the shaking range of the vehicle body, and improves the driving experience.
Smart Images
Figure CN119611506A_ABST
Abstract
Description
Technical Field
[0001] Embodiments of the present application relate to the field of vehicle control technology, and in particular, to a vehicle steering control method, system, automatic driving device, and readable storage medium. Background Art
[0002] Autonomous driving technology has become a widely used technology that can assist drivers in controlling vehicles, thereby alleviating the driver's driving burden and improving the safety and stability of vehicles. When the current autonomous driving technology makes a large curvature turn, the actual speed of the vehicle is inconsistent with the planned speed direction. The actual speed of the vehicle will increase or decrease sharply, causing the vehicle body to shake greatly, affecting the driving experience. Summary of the invention
[0003] The embodiments of the present application aim to provide a vehicle steering control method, system, automatic driving device and readable storage medium to solve the technical problem in the prior art that the actual vehicle speed is inconsistent with the planned speed direction in a large curvature steering scenario, resulting in large vehicle body shaking.
[0004] In order to solve the above technical problems, the embodiments of the present application disclose the following technical solutions:
[0005] In a first aspect, an embodiment of the present application provides a vehicle steering control method, comprising:
[0006] Determine the starting and ending points of the curves in the planned driving path;
[0007] Dividing the driving path into a plurality of segments based on the starting point and the ending point;
[0008] Determine the direction vector of each segment path;
[0009] Determine the speed of the front wheels of the vehicle in each segment of the segmented path based on the direction vector;
[0010] determining an acceleration of the vehicle based on the vehicle speed;
[0011] A travel speed of the vehicle while traveling along the curve is controlled based on the acceleration.
[0012] In a second aspect, an embodiment of the present application provides a vehicle steering control system, comprising:
[0013] A planning module, the planning module being configured to determine a starting point and an ending point of a curve in a planned driving path;
[0014] a division module, the division module being configured to divide the driving path into a plurality of segments based on the starting point and the ending point;
[0015] A first operation module, wherein the first operation module is configured to determine a direction vector of each segmented path;
[0016] A second computing module, the second computing module is configured to determine the speed of the front wheels of the vehicle in each segmented path based on the direction vector;
[0017] a third computing module, the third computing module being configured to determine an acceleration of the vehicle based on the vehicle speed;
[0018] A control module is configured to control a driving speed of the vehicle when traveling along the curve based on the acceleration.
[0019] In a third aspect, an embodiment of the present application provides a vehicle steering control system, including:
[0020] Memory, used to store programs;
[0021] A processor, configured to execute a program stored in the memory;
[0022] When the program stored in the memory is executed, the processor performs the vehicle steering control method as described in any one of the first aspects.
[0023] In a fourth aspect, an embodiment of the present application provides an autonomous driving device, which includes a vehicle steering control system as described in the second aspect.
[0024] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores instructions for execution by a computing device. When the computing device executes the instructions, it implements the vehicle steering control method as described in any one of the first aspects.
[0025] One of the above technical solutions has the following advantages or beneficial effects:
[0026] The embodiment of the present application provides a vehicle steering control method, including: determining the starting point and the ending point of the curve in the planned driving path; dividing the driving path into multiple segments based on the starting point and the ending point; determining the direction vector of each segmented path; determining the speed of the front wheels of the vehicle in each segmented path based on the direction vector; determining the acceleration of the vehicle based on the speed; and controlling the driving speed of the vehicle along the curve based on the acceleration. The vehicle steering control method provided by the present application calculates the direction vector of each segmented path in the curve, and corrects the speed of the front wheels of the vehicle according to the direction vector, so that the actual speed of the vehicle is consistent with the planned speed, the actual speed of the vehicle is smoothly controlled, the sudden acceleration and deceleration of the vehicle is reduced, the vibration amplitude of the vehicle body is reduced, and the driving experience is improved.
[0027] The embodiment of the present application also provides a vehicle steering control system, including: a planning module, the planning module is configured to determine the starting point and the end point of the curve in the planned driving path; a division module, the division module is configured to divide the driving path into multiple segments based on the starting point and the end point; a first operation module, the first operation module is configured to determine the direction vector of each segmented path; a correction module, the correction module is configured to determine the speed of the front wheels of the vehicle in each segmented path based on the direction vector; a second operation module, the second operation module is configured to determine the acceleration of the vehicle based on the speed; a control module, the control module is configured to control the driving speed of the vehicle when driving along the curve based on the acceleration. The vehicle steering control system provided by the present application calculates the direction vector of each segmented path in the curve, and corrects the speed of the front wheels of the vehicle according to the direction vector, so that the actual speed of the vehicle is consistent with the planned speed, the actual speed of the vehicle is controlled smoothly, the sudden acceleration and deceleration of the vehicle is reduced, the vibration amplitude of the vehicle body is reduced, and the driving experience is improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The technical solution and other beneficial effects of the present application will be made apparent by describing in detail the specific implementation methods of the present application in conjunction with the accompanying drawings.
[0029] Figure 1 A schematic diagram of the steps of a vehicle steering control method provided in an embodiment of the present application;
[0030] Figure 2 A schematic diagram of a segmented driving path provided in an embodiment of the present application;
[0031] Figure 3 A schematic diagram of the direction vector of the driving path provided in the embodiment of the present application;
[0032] Figure 4 A schematic diagram of a vehicle speed planning structure provided in an embodiment of the present application;
[0033] Figure 5 This is an equivalent schematic diagram of vehicle speed planning provided in an embodiment of the present application;
[0034] Figure 6 A schematic diagram of a vehicle driving path structure provided in an embodiment of the present application;
[0035] Figure 7 A schematic diagram of a vehicle driving path structure provided for some embodiments of the present application;
[0036] Figure 8 A schematic diagram of a module of a vehicle steering control system provided in an embodiment of the present application;
[0037] Fig. 9 A block diagram of the vehicle system module of the vehicle provided in an embodiment of the present application.
[0038] The reference numerals are as follows:
[0039] 100-vehicle, 200-driving path, 300-target stop location. DETAILED DESCRIPTION
[0040] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. In the description of the present application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.
[0041] The relevant technical personnel of this application have noticed that in the existing autonomous driving, there are many solutions for speed planning, which are generally the following: 1) Use third-order, fifth-order, and seventh-order polynomials to fit the speed, acceleration, and acceleration curves, and obtain the unknown coefficients of the polynomials by setting different initial and final boundary conditions, so as to obtain a smooth speed curve. 2) Construct a position and time graph (ST graph), project the obstacles (including vehicles) into the ST graph, and then scatter the position and time to find a series of discrete points that bypass all obstacles through dynamic programming. 3) On the basis of dynamic programming as a rough solution, by using the discrete points in the ST graph found, a quadratic optimization problem that satisfies its first-order and second-order smoothness is constructed, and a continuous and smooth speed curve is obtained by solving the quadratic optimization problem. Similarly, on the basis of the discrete points obtained by dynamic programming, a nonlinear optimization problem that satisfies the first-order and second-order smoothness of the curve is constructed, and a continuous and smooth speed curve is obtained by solving a nonlinear optimization problem.
[0042] The current speed planning mainly takes the longitudinal axis of the vehicle as the positive direction, that is, the longitudinal speed of the vehicle is planned. This speed planning is mostly used in scenarios where the vehicle is driving in a straight line or turning with a small curvature, but it is not completely applicable to scenarios where the vehicle is turning with a large curvature. In large curvature turning, the planned speed direction, that is, the longitudinal axis direction of the vehicle, is inconsistent with the tangent direction of the driving path point and the rotation direction of the tire.
[0043] This results in the vehicle's actual speed being inconsistent with the planned speed direction, making it difficult to reach the planned target speed. In addition, in large curvature turns, the planned speed direction also changes due to the continuous change of curvature, which makes it even more difficult for the actual speed to follow the planned speed.
[0044] Especially in low-speed scenarios with large curvature turns, the sudden increase and decrease in vehicle speed will be very obvious, and can be easily perceived by the driver, causing discomfort.
[0045] The application scenario of this application is mainly for the large curvature path scenario during parking. Since the overall vehicle speed is low during parking, the slight speed fluctuation is very easy to be perceived by the driver. Therefore, this application has a significant improvement on the speed abnormality during this period. For the large curvature path scenario of the high-speed scene.
[0046] In the embodiments of the present application, the vehicle can be used to represent a device equipped with autonomous driving technology, including a two-wheeled vehicle, a three-wheeled vehicle or a unicycle.
[0047] The specific implementation methods of the present application are described below by way of examples:
[0048] like Figures 1 to 5 As shown, an embodiment of the present application provides a vehicle steering control method, comprising:
[0049] S1: Determine the starting point and the ending point of the curve in the planned driving path.
[0050] like Figure 2 and Figure 3 As shown, the specific method includes the following steps:
[0051] Select multiple pre-selected points on the driving path; construct a Cartesian coordinate system based on the driving path to determine the coordinates of the multiple pre-selected points; determine the curvature of the multiple pre-selected points based on the coordinates. Specifically, multiple pre-selected points can be selected on the driving path in a random manner or with a certain length, and the slope of each pre-selected point is calculated according to the coordinate value of each pre-selected point. It is determined whether the driving path enters a curve according to the change in the slope. When the curvature of the multiple pre-selected points increases, the pre-selected point where the curvature changes is used as the starting point P. 1 ; When the curvature of multiple pre-selected points decreases, the pre-selected point where the curvature changes is taken as the end point P n .
[0052] In the embodiment of the present application, the driving path planning method includes: determining the current position and target parking position of the vehicle; determining the current position of the vehicle through the vehicle's built-in positioning sensor, and identifying the parking space information through the vehicle's built-in camera, ultrasonic sensor, millimeter wave radar, laser radar, infrared sensor and parking space sensor, and projecting or displaying the identified parking space on the car screen. The owner can select the corresponding parking space by touching the car screen or the car system selects the corresponding parking space to determine the target parking position of the vehicle. Before the vehicle stops, the surrounding environment is detected by the vehicle's built-in camera, ultrasonic sensor, millimeter wave radar, laser radar, infrared sensor and parking space sensor to confirm that there are no people, animals, vehicles or other obstacles in the surrounding environment. Thereby avoiding accidents such as collision or scratching of the vehicle during the parking process to improve the safety of vehicle parking. Before the vehicle stops, it is also necessary to determine the body state of the vehicle according to the shape and geographical location of the target parking position. For example, the shape of the target parking position is a parking space in an inclined direction or a narrow parking space, or the target parking position is not suitable for reverse entry or it is inconvenient to drive out directly after reverse entry. The vehicle is then adjusted to reverse into the target parking position or drive directly into the target parking position so that subsequent vehicles can drive out safely. After determining the vehicle's current position, target parking position and body status. The vehicle computer system takes the vehicle's current position as the starting point and the target parking position as the end point, and plans the vehicle's driving path based on the body status. The vehicle computer system controls the vehicle to move according to the driving path to complete the vehicle's parking task. It is worth noting that the vehicle computer can plan multiple driving paths, and the owner can choose according to actual conditions. If the owner does not make a choice within a certain period of time, the vehicle computer defaults to the first driving path as the parking path.
[0053] It can be understood that through the matching control of the vehicle's own multiple sensors and the vehicle-computer system, the vehicle can independently select the target parking position, which improves the convenience of the vehicle when parking; at the same time, the vehicle can also confirm the safety of the surrounding environment, which improves the safety of the vehicle when parking; the vehicle can also take into account the body status in combination with the target parking position, and take into account the departure of subsequent vehicles, which improves the vehicle's predictability of future events and improves the humanization of the vehicle-computer system.
[0054] S2: Divide the driving route into multiple segments based on the starting point and the ending point.
[0055] like Figure 3 As shown, the specific method includes the following steps:
[0056] Determine multiple segmentation points on the driving path, such as Figure 2 P shown in 1 ~P n , P 1 ~P nThe coordinates of are {(x p1 ,y p1 ),(x p2 ,y p2 ),···,(x pn ,y pn )}; Based on the starting point, the ending point and multiple segmentation points, the driving path is divided into multiple segments; wherein the segmentation step between each segmentation point and the adjacent previous segmentation point is determined according to the curvature value of the adjacent previous segmentation point, the segmentation step between the first segmentation point and the starting point is determined according to the curvature value of the starting point, and the last segmentation point coincides with the ending point. Specifically, determine the starting point P 1 The first curvature value k 1 ; Starting point P 1 Take a small arc length ds as the center; calculate the angle change corresponding to the small arc length The first curvature value k can be calculated by finding the angle between the tangent direction of the curve at this point and the tangent direction of the curve at the small arc length ds. 1 , which is the first curvature value Based on the first curvature value k 1 Determine the first segment step size s 1 The formula is:
[0057] s n =s 0 -κ n β,(n=1);
[0058] In the above formula, s 0 represents the current position, and β is the curvature gain coefficient.
[0059] Based on the first segment step size s 1 Determine the first segmentation point P on the driving path 2 . Starting point P 1 As the center of the circle, with the first segment step length s 1 Draw an arc with the radius along the moving direction of the driving path, and take the intersection of the arc and the driving path as the first segmentation point P 2 The first segmentation point P is determined in the same way. 2 The second curvature value k 2 ; and combine the first curvature value k with the same formula 1 and the second curvature value k 2 Determine the second segment step size s 2 ; The calculation formula is:
[0060] s n =s n-1 -(κ n -κ n-1 )γ,n>1; in the above formula, γ is the curvature gain coefficient.
[0061] Then take the first segment point P 2 As the center of the circle, with the second segment step length s 2 Draw an arc with the radius along the moving direction of the driving path, and use the intersection of the arc and the driving path as the second segmentation point P 3 ; And so on, until the last segmentation point and the end point P n Overlap, that is Figure 2 and Figure 3 As shown, the final set of all points is {P 1 ,P 2 ,P 3 …,P 13 ,…,P n}, thereby obtaining n-1 segmented paths {S 1 ,S 2 ,S 3 …,S 12 ,…,S n-1}.
[0062] It can be understood that by segmenting the curves in the driving path, the speed control of the large curvature curve is refined into the speed control of multiple small curvature paths, thereby realizing multi-point speed control of the curve, so as to facilitate the planning of the vehicle speed, so that the planned speed and actual speed of the vehicle can maintain the same direction and size, thereby reducing the sudden increase or decrease of the vehicle speed due to speed mismatch, making the vehicle speed more continuous and reducing the shaking of the vehicle body.
[0063] S3: Determine the direction vector of each segment path.
[0064] like Figures 1 to 5 As shown, the specific method includes the following steps:
[0065] Determine the coordinate values of the two endpoints of each segment path; such as the first segment step length s 1 The coordinates of the two endpoints are the starting point P 1 and the first segment point P 2 , whose coordinates are (x p1 ,y p1 ) and (x p2 ,y p2 );Subtract the coordinate values of the two endpoints to obtain the difference vector; 2 minus the starting point P 1 The coordinates are obtained by the difference vector; the difference vector is divided by the segmented step size corresponding to the segmented path to obtain the direction vector of the segmented path; the difference vector is divided by the first segmented step size s 1 Get the direction vector The same operation is performed on other segmented paths to obtain the direction vector of each segmented path. Finally, {P 1 ,P 2 ,P 3 …,P 13 ,…,P n The direction vectors of} are Specifically, the direction vector is the set speed of the vehicle when the vehicle passes through each segmentation point. By setting the speed, the speed and speed direction of the vehicle when it safely passes through each segmentation point can be determined.
[0066] It can be understood that by solving the direction vector of each segment point, the set value of the vehicle speed when the vehicle passes each segment point is determined, thereby ensuring that the vehicle can smoothly pass through the curve. At the same time, after determining the vehicle speed setting direction, it can also assist in controlling the actual speed of the vehicle, thereby improving the consistency between the actual speed of the vehicle and the planned speed.
[0067] S4: Determine the speed of the front wheels of the vehicle in each segmented path based on the direction vector.
[0068] like Figures 1 to 5 As shown, the specific method includes the following steps:
[0069] The center point of the front axle of the vehicle is selected as the reference point. Specifically, since the two wheels of the vehicle are respectively on the inside and outside of the curve when turning, the forces on the two wheels are inconsistent when turning. Therefore, the dual-track model of the vehicle is converted into a single-track model, that is, the two wheels are regarded as one wheel and converged to the center point of the front axle of the vehicle, and the center point of the front axle is used as a reference point for analysis; in response to the overlap of the reference point with the starting point or the segmentation point of the segmented path, the steering angle of the front wheel of the vehicle and the angle between the direction vector and the longitudinal axis of the vehicle are determined; when the reference point overlaps with the starting point or the segmentation point, it means that the wheel is passing through the starting point or the segmentation point. At this time, the steering angle δ of the front wheel of the vehicle is confirmed and converted into the wheel steering angle δ′ under the single-track model. At the same time, it is also necessary to confirm the angle θ between the direction vector of the starting point or the segmentation point and the longitudinal axis of the vehicle; based on the direction vector, the angle and the steering angle, the speed of the front wheel of the vehicle is determined as the first speed. The specific steps are: determine the set speed V of the direction vector set ; Based on the product of the set speed and the cosine value of the angle, the second speed of the longitudinal axis of the vehicle is obtained; based on the product of the second speed and the cosine value of the steering angle, the first speed is obtained. The specific calculation formula is:
[0070]
[0071] Where V setNew is the first speed, and α is the adjustment coefficient, which is used to correct the speed deviation between the front wheels of the vehicle and the longitudinal axis of the vehicle.
[0072] It can be understood that by correcting the speed of the vehicle's front wheels, the speed of the vehicle when passing each segmented point can be effectively controlled, thereby reducing the deviation between the actual speed of the vehicle's front wheels and the planned speed of the vehicle, thereby reducing the sudden increase or decrease in the vehicle speed due to speed mismatch, making the vehicle speed more continuous and reducing the shaking of the vehicle body.
[0073] S5: Determine the acceleration of the vehicle based on the vehicle speed.
[0074] The specific method includes the following steps:
[0075] Determine the initial speed of the vehicle before it enters the starting point. Determine the first speed of the vehicle at each segment point; based on the relationship between the initial speed, the first speed and the acceleration, obtain the relationship between the acceleration and the duration; based on the segment step size, the first speed and the relationship between the acceleration and the duration, obtain the acceleration and duration of the vehicle at each waypoint.
[0076] Specifically, a fifth-order polynomial function is used as the highest-order function to describe the segmented step length s, while the speed v is described by its reduced fourth-order function, the acceleration a is a third-order function, and the jerk j is a second-order function. Thus, the trajectory equation of the vehicle planning can be obtained as:
[0077]
[0078] In the above formula, s 0 Indicates the current position, v 0 Indicates the current vehicle speed, a 0 represents the current acceleration, j 0 Indicates the current acceleration;
[0079] The starting boundary conditions are:
[0080]
[0081] End boundary conditions:
[0082]
[0083] The coefficient c is adjusted by setting different time parameters t 3 ,c 4 ,c 5 The accurate solution of the acceleration curve is obtained to obtain a continuous acceleration curve.
[0084] It is understandable that by controlling the magnitude of the vehicle's acceleration, the vehicle can be controlled to actively accelerate and decelerate, thereby controlling the vehicle to pass through a curve at a certain speed along the driving path. Therefore, by calculating the acceleration of the vehicle when passing through multiple segmented paths, the vehicle speed can be accurately controlled when passing through a curve, avoiding the vehicle body from shaking due to excessive speed or too slow speed, thereby improving the comfort of the driver and passengers.
[0085] S6: Controlling the driving speed of the vehicle along a curve based on the acceleration.
[0086] The specific method includes the following steps:
[0087] The driving speed of the vehicle passing each segment point is controlled based on acceleration and duration. Specifically, when the acceleration magnitude and duration of the vehicle passing each segment point are determined, the vehicle speed can be accurately controlled by determining the position of the reference point and the starting point or segment point, so that the vehicle can pass the curve according to the planned speed and driving path, improving the stability and smoothness of the vehicle.
[0088] like Figure 8 As shown, an embodiment of the present application provides a vehicle steering control system, including: a planning module, a division module, a first operation module, a second operation module, a third operation module and a control module; the planning module is configured to determine the starting point and the end point of the curve in the planned driving path.
[0089] Specifically, the current position of the vehicle is determined by the vehicle's built-in positioning sensor, and the parking space information is identified by the vehicle's built-in camera, ultrasonic sensor, millimeter-wave radar, laser radar, infrared sensor and parking space sensor, and the identified parking space is projected or displayed on the vehicle screen. The owner can select the corresponding parking space by touching the vehicle screen or the vehicle system can select the corresponding parking space to determine the target parking position of the vehicle. Before the vehicle stops, the surrounding environment is detected by the vehicle's built-in camera, ultrasonic sensor, millimeter-wave radar, laser radar, infrared sensor and parking space sensor to confirm that there are no people, animals, vehicles or other obstacles in the surrounding environment. This avoids accidents such as collisions or scratches during the parking process to improve the safety of vehicle parking. Before the vehicle stops, the vehicle's body state needs to be determined according to the shape and geographical location of the target parking position. For example, the shape of the target parking position is a parking space in an inclined direction or a narrow parking space, or the target parking position is not suitable for reverse entry or it is inconvenient to drive out directly after reverse entry. The vehicle is then adjusted to reverse into the target parking position or drive directly into the target parking position so that subsequent vehicles can drive out safely. After determining the vehicle's current position, target parking position and body status. The vehicle computer system takes the vehicle's current position as the starting point and the target parking position as the end point, and plans the vehicle's driving path based on the body status. The vehicle computer system controls the vehicle to move according to the driving path to complete the vehicle's parking task. It is worth noting that the vehicle computer can plan multiple driving paths, and the owner can choose according to actual conditions. If the owner does not make a choice within a certain period of time, the vehicle computer defaults to the first driving path as the parking path.
[0090] In the embodiment of the present application, the division module is configured to divide the driving path into multiple segments based on the starting point and the end point. By segmenting the curves in the driving path, the speed control of the curve with large curvature is refined into the speed control of multiple paths with small curvatures, thereby realizing multi-point speed control of the curve, so as to plan the vehicle speed, so that the planned speed and the actual speed of the vehicle can maintain the same direction and size, thereby reducing the sudden increase or decrease of the vehicle speed due to speed mismatch, making the vehicle speed more continuous and reducing the shaking of the vehicle body.
[0091] In the embodiment of the present application, the first operation module is configured to determine the direction vector of each segmented path. Specifically, the direction vector of each segment point is obtained by solving to determine the set value of the vehicle speed when the vehicle passes each segment point, thereby ensuring that the vehicle can smoothly pass through the curve. At the same time, after determining the vehicle speed setting direction, it can also assist in controlling the actual speed of the vehicle, thereby improving the consistency between the actual speed of the vehicle and the planned speed.
[0092] In the embodiment of the present application, the second operation module is configured to correct the speed of the front wheels of the vehicle in each segmented path based on the direction vector. Specifically, by correcting the speed of the front wheels of the vehicle, the speed of the vehicle when passing each segment point can be effectively controlled, thereby reducing the deviation between the actual speed of the front wheels of the vehicle and the planned speed of the vehicle, thereby reducing the sudden increase or decrease of the vehicle speed due to speed mismatch and reducing the shaking of the vehicle body.
[0093] In an embodiment of the present application, the third operation module is configured to determine the acceleration of the vehicle based on the vehicle speed. Specifically, by determining the initial velocity of the vehicle before entering the starting point, the first velocity of the vehicle passing through each segmented point; and based on the relationship between the initial velocity, the first velocity and the acceleration, the relationship between the acceleration and the duration is obtained; based on the segmented step size, the first velocity and the relationship between the acceleration and the duration, the acceleration and duration of the vehicle at each passing point are obtained. By controlling the magnitude of the vehicle's acceleration, the vehicle can be controlled to actively accelerate and decelerate, thereby controlling the vehicle to pass through the curve at a certain speed along the driving path. Therefore, by calculating the acceleration of the vehicle when passing through multiple segmented paths, the speed of the vehicle can be accurately controlled when passing through the curve, avoiding the vehicle's body shaking due to the vehicle's speed being too fast or too slow, thereby improving the comfort of the driver and passengers.
[0094] In the embodiment of the present application, the control module is configured to control the driving speed of the vehicle when it is driving along a curve based on acceleration. Specifically, when the magnitude of acceleration and the duration of acceleration when the vehicle passes each segmentation point are determined, the speed of the vehicle can be accurately controlled by determining the position of the reference point and the starting point or the segmentation point, so that the vehicle can pass through the curve according to the planned speed and driving path, thereby improving the stability and smoothness of the vehicle.
[0095] An embodiment of the present application provides a vehicle steering control system, including a memory and a processor; the memory is used to store a computer program; the processor is used to implement a vehicle steering control method provided in any of the above embodiments when executing the computer program.
[0096] like Fig. 9As shown, the embodiment of the present application provides an automatic driving device, including a fisheye camera, an automotive digital cockpit unit (ADCU) and a car bus; wherein the automotive digital cockpit unit includes a perception module, a positioning module, a slot planning module, a behavior planning module and a wheel motion control module; the perception module is used to obtain image data collected by the fisheye camera, and analyze the image data to obtain the protruding parts therein; the positioning module is used to construct a coordinate system and further determine the current position of the vehicle and the position of the protruding parts, the behavior planning module is used to plan the behavior of the vehicle, the vehicle motion control module is used to control the moving speed, acceleration and other data of the vehicle, and the slot planning module is used to plan the state of the slot in the vehicle, thereby outputting the corresponding data to the car bus, and the car bus is used to connect the automotive digital cockpit unit and the microcomputer, and is used to transmit data to the response components of the vehicle, thereby controlling the movement of the vehicle. The vehicle provided in the present application is controlled by the vehicle steering control method provided in any of the above embodiments, or the vehicle includes the vehicle steering control system provided in the above embodiments.
[0097] An embodiment of the present application provides a computer-readable storage medium, which stores instructions for execution by a computing device. When the computing device executes the instructions, the vehicle steering control method provided in any of the above embodiments is implemented.
[0098] The above is a detailed introduction to a vehicle steering control method, system, automatic driving device and readable storage medium provided in the embodiments of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solutions and core ideas of the present application. Ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.
Claims
1. A vehicle steering control method, characterized in that: include: Determine the starting and ending points of the curves in the planned driving path; Dividing the driving path into a plurality of segments based on the starting point and the ending point; Determine the direction vector of each segment path; Determine the speed of the front wheels of the vehicle in each segment of the segmented path based on the direction vector; determining an acceleration of the vehicle based on the vehicle speed; A travel speed of the vehicle while traveling along the curve is controlled based on the acceleration.
2. The vehicle steering control method according to claim 1, characterized in that: The method for dividing the driving path into multiple segments based on the starting point and the ending point comprises: Determine a plurality of segmentation points on the driving path; Divide the driving path into multiple segments based on the starting point, the ending point and the multiple segmentation points; Among them, the segmentation step between each segmentation point and the adjacent previous segmentation point is determined according to the curvature value of the adjacent previous segmentation point, the segmentation step between the first segmentation point and the starting point is determined according to the curvature value of the starting point, and the last segmentation point coincides with the ending point.
3. The vehicle steering control method according to claim 1, characterized in that: The method for determining the speed of the front wheels of the vehicle in each segmented path based on the direction vector comprises: Selecting the center point of the front axle of the vehicle as a reference point; In response to the reference point overlapping the starting point or the segmented point of the segmented path, determining the steering angle of the front wheels of the vehicle and the angle between the direction vector and the longitudinal axis of the vehicle; Based on the direction vector, the included angle and the steering angle, a speed of the front wheels of the vehicle is determined to be a first speed.
4. The vehicle steering control method according to claim 3, characterized in that: The method for determining the speed of the front wheels of the vehicle as a first speed based on the direction vector, the included angle and the steering angle includes: determining a set speed of the direction vector; Obtaining a second speed of the longitudinal axis of the vehicle based on the product of the set speed and the cosine value of the angle; The first speed is obtained based on the product of the second speed and the cosine value of the steering angle.
5. The vehicle steering control method according to claim 4, characterized in that: The method for determining the acceleration of the vehicle based on the vehicle speed includes: Determining the initial velocity of the vehicle before entering the starting point; Determining the first speed of the vehicle passing through each of the segmented points; Based on the relationship between the initial velocity, the first velocity and the acceleration, obtaining a relationship between the acceleration and the duration; Based on the segmented step size, the first speed, and the relationship between the acceleration and the duration, the acceleration and the duration of the vehicle at each waypoint are obtained.
6. The vehicle steering control method according to claim 5, characterized in that: The method for controlling the driving speed of the vehicle when driving along the curve based on the acceleration includes: A travel speed of the vehicle passing each of the segment points is controlled based on the acceleration and the duration.
7. The vehicle steering control method according to claim 1, characterized in that: The driving path planning method further includes: Determining a current position and a target parking position of the vehicle; A driving path is planned based on the current position and the target stop position.
8. The vehicle steering control method according to claim 1, characterized in that: The method for determining the starting point and the ending point of the curve in the planned driving path includes: Selecting a plurality of preselected points in the driving path; determining the curvature of the plurality of preselected points; When the curvature of the plurality of pre-selected points increases, the pre-selected point where the curvature changes is taken as a starting point; When the curvature of the plurality of preselected points decreases, the preselected point where the curvature changes is taken as the termination point.
9. The vehicle steering control method according to claim 1, characterized in that: The method for determining the direction vector of each segmented path comprises: Determine the coordinate values of two endpoints of each segment path; Subtract the coordinate values of the two endpoints to obtain a difference vector; The quotient of the difference vector and the segment step length corresponding to the segment path is determined as the direction vector corresponding to the segment path.
10. A vehicle steering control system, characterized in that: include: A planning module, the planning module being configured to determine a starting point and an ending point of a curve in a planned driving path; a division module, the division module being configured to divide the driving path into a plurality of segments based on the starting point and the ending point; A first operation module, wherein the first operation module is configured to determine a direction vector of each segmented path; A second operation module, the second operation module is configured to correct the speed of the front wheels of the vehicle in each segmented path based on the direction vector; a third computing module, the third computing module being configured to determine an acceleration of the vehicle based on the vehicle speed; A control module is configured to control a driving speed of the vehicle when traveling along the curve based on the acceleration.
11. A vehicle steering control system, characterized in that: include: Memory, used to store programs; A processor, configured to execute a program stored in the memory; When the program stored in the memory is executed, the processor executes the vehicle steering control method according to any one of claims 1 to 9.
12. An automatic driving device, characterized in that: The automatic driving device includes a vehicle steering control system as described in claim 10.
13. A computer-readable storage medium, characterized in that: The computer-readable medium stores instructions for execution by a computing device, and when the computing device executes the instructions, the vehicle steering control method according to any one of claims 1 to 9 is implemented.