Method and system for determining turning angle of steering wheel and vehicle

Abstract

The embodiment of the invention provides a method and system for determining a steering wheel rotation angle and a vehicle, relates to the technical field of vehicles, and can accurately determine the steering wheel rotation angle under complex and changeable road conditions. The method for determining the turning angle of the steering wheel comprises the steps that a current position point is obtained; determining a feedforward preview point and a feedback pre-anchor point corresponding to the current position point in a pre-planned driving track curve; determining a feedforward steering wheel turning angle according to the current position point, the feedforward preview point and the vehicle attribute parameters; determining a driving state deviation according to the current position point and the feedback preview point; feedback adjustment is conducted according to the driving state deviation, and a feedback steering wheel rotation angle is obtained; and determining a target steering wheel rotation angle according to the feedforward steering wheel rotation angle and the feedback steering wheel rotation angle.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a method and system for determining a steering wheel angle, and a vehicle. Background Art

[0002] With the rapid development of intelligent driving technology, vehicle trajectory tracking has become an essential component of autonomous driving. To achieve reliable vehicle trajectory tracking, accurately determining the steering wheel angle under complex and changing road conditions is an urgent problem that needs to be solved. Summary of the Invention

[0003] Embodiments of the present application provide a method, system, and vehicle for determining a steering wheel angle, which can accurately determine the steering wheel angle under complex and changing road conditions.

[0004] In a first aspect, an embodiment of the present application provides a method for determining a steering wheel angle, the method comprising: Get the current location; Determining a feedforward pre-aiming point and a feedback pre-anchor point corresponding to the current position point in a pre-planned driving trajectory curve; Determining a feedforward steering wheel angle according to the current position point, the feedforward preview point, and vehicle attribute parameters; Determining a driving state deviation based on the current position point and the feedback preview point; performing negative feedback adjustment according to the driving state deviation to obtain a feedback steering wheel angle; A target steering wheel angle is determined according to the feedforward steering wheel angle and the feedback steering wheel angle.

[0005] In this embodiment, a feedforward pre-anchor point and a feedback pre-anchor point are determined based on the current position within a pre-planned driving trajectory. Based on this, the feedforward steering wheel angle is accurately determined by combining the current position, the feedforward pre-anchor point, and vehicle attribute parameters. Furthermore, the driving state deviation is accurately determined by combining the current position and the feedback pre-anchor point. Feedback adjustment of the driving state deviation is then performed to obtain the feedback steering wheel angle. Finally, the target steering wheel angle is obtained by combining the feedforward steering wheel angle and the feedback steering wheel angle. This method, on the one hand, can predict in advance the steering wheel angle required to smoothly pass the complex and changeable road ahead (i.e., the feedforward steering wheel angle). This advance response mechanism enables the vehicle to prepare for steering before reaching a specific position, avoiding trajectory deviation caused by reaction lag, and helping to achieve smoother and more accurate trajectory tracking. On the other hand, it can calculate in real time the steering wheel angle used to correct the deviation between the vehicle's actual driving trajectory and the preset driving trajectory (i.e., the feedback steering wheel angle). This ability to correct deviations in real time makes the feedback control highly robust to various uncertainties and unmodeled dynamics, and can ensure that the vehicle tracks the desired trajectory as closely as possible under complex and changeable road conditions.

[0006] Optionally, determining a feedforward pre-aiming point and a feedback pre-anchor point corresponding to the current position point in the pre-planned driving trajectory curve includes: Determining a reference position point in the driving trajectory curve that matches the current position point; The feedforward pre-aiming point and the feedback pre-anchor point corresponding to the reference position point are determined in the driving trajectory curve.

[0007] In an embodiment of the present application, a reference position point that matches the current position is determined on a pre-planned driving trajectory curve, and then the feedforward pre-anchor point and the feedback pre-anchor point can be more accurately determined based on the reference position point.

[0008] Optionally, determining the feedforward preview point corresponding to the reference position point in the driving trajectory curve includes: Obtaining the current vehicle speed, and obtaining the maximum curvature of the driving trajectory curve and the corresponding maximum curvature position point; Determining a first candidate pre-anchor distance according to the current vehicle speed and the first pre-anchor time; In response to the maximum curvature being greater than a set curvature threshold, determining a second candidate pre-anchor distance according to the reference position point and the maximum curvature position point; Determining a feedforward pre-anchor distance based on the first candidate pre-anchor distance and the second candidate pre-anchor distance; In the driving trajectory curve, the feedforward pre-aiming point is determined according to the reference position point and the feedforward pre-anchor distance.

[0009] In the embodiment of the present application, without considering road changes, the first candidate pre-anchor distance is preliminarily determined based on the current vehicle speed and the first pre-anchor duration; taking into account road changes, if a large curve appears at a certain point on the road ahead, the second candidate pre-anchor distance is determined based on the reference position and the location of the large curve. Finally, the feedforward pre-anchor distance is accurately determined based on the first candidate pre-anchor distance and the second candidate pre-anchor distance, and then the corresponding feedforward pre-anchor point is determined. Optionally, before determining the feedforward pre-anchor distance according to the first candidate pre-anchor distance and the second candidate pre-anchor distance, the method includes: Obtaining an average of actual curvatures of a plurality of position points within a preset distance after the reference position point in the driving trajectory curve; According to the correspondence between the mean curvature and the minimum pre-anchor distance, the minimum pre-anchor distance corresponding to the actual mean curvature is determined and used as the third candidate pre-anchor distance; Determining a feedforward pre-anchor distance according to the first candidate pre-anchor distance and the second candidate pre-anchor distance includes: The feedforward pre-anchor distance is determined according to the first candidate pre-anchor distance, the second candidate pre-anchor distance, and the third candidate pre-anchor distance.

[0010] In an embodiment of the present application, before determining the feedforward pre-anchor distance, the corresponding minimum pre-anchor distance can be determined based on the curvature mean of multiple position points within a preset distance after the reference position point, and the minimum pre-anchor distance is used as the third candidate pre-anchor distance. Then, the feedforward pre-anchor distance is determined from the first candidate pre-anchor distance, the second candidate pre-anchor distance and the third candidate pre-anchor distance, so as to avoid the determined feedforward pre-anchor distance being too small.

[0011] Optionally, determining the feedforward pre-anchor distance according to the first candidate pre-anchor distance, the second candidate pre-anchor distance, and the third candidate pre-anchor distance includes: performing a smaller operation on the first candidate pre-anchor distance and the second candidate pre-anchor distance to determine a feedforward candidate pre-anchor distance; A larger operation is performed on the feedforward candidate pre-anchor distance and the third candidate pre-anchor distance to determine the feedforward pre-anchor distance.

[0012] In an embodiment of the present application, by minimizing the first candidate pre-anchor distance and the second candidate pre-anchor distance, the determined feedforward candidate pre-anchor distance can be made applicable to the complex and changeable roads ahead; on this basis, by maximizing the feedforward candidate pre-anchor distance and the third candidate pre-anchor distance, it is possible to avoid making the determined feedforward pre-anchor distance too small, while also being applicable to the complex and changeable roads ahead.

[0013] Optionally, the feedback pre-anchor point includes a lateral feedback pre-anchor point and a heading feedback pre-anchor point, and determining the feedback pre-anchor point corresponding to the reference position point in the driving trajectory curve includes: determining a fourth candidate pre-anchor distance based on the current vehicle speed and the second pre-anchor time; Determine the lateral deviation corresponding to the reference position point in the driving trajectory curve according to the third candidate pre-anchor distance and the fourth candidate pre-anchor distance and select a pre-anchor point; determining a fifth candidate pre-anchor distance according to the current vehicle speed and a third pre-anchor time, wherein the third pre-anchor time is greater than the second pre-anchor time; Determining a lateral deviation elimination pre-anchor point corresponding to the reference position point in the driving trajectory curve according to the third candidate pre-anchor distance and the fifth candidate pre-anchor distance; The lateral deviation selection pre-anchor point and the lateral deviation elimination pre-anchor point are used as the lateral feedback pre-anchor points; determining a sixth candidate pre-anchor distance based on the current vehicle speed and the fourth pre-anchor time; The heading feedback pre-anchor point corresponding to the reference position point is determined in the driving trajectory curve according to the third candidate pre-anchor distance and the sixth candidate pre-anchor distance.

[0014] In the embodiment of the present application, a lateral feedback pre-anchor point and a heading feedback pre-anchor point are determined in the pre-planned driving trajectory curve, so that the lateral deviation and the heading deviation can be determined more accurately later.

[0015] Optionally, the driving state deviation includes a lateral driving state deviation and a heading driving state deviation, and determining the driving state deviation according to the current position point and the feedback preview point includes: Determining a lateral deviation reference position point corresponding to the lateral deviation selection pre-anchor point in the driving trajectory curve; Determining the lateral driving state deviation between the lateral deviation selection pre-anchor point and the lateral deviation reference position point; In the driving trajectory curve, the heading driving state deviation is determined according to the heading deviations of a plurality of position points between the reference position point and the heading feedback pre-anchor point.

[0016] In an embodiment of the present application, the lateral driving state deviation can be conveniently determined by selecting a pre-anchor point and a lateral deviation reference position point based on the lateral deviation; at the same time, the heading driving state deviation can be jointly determined based on the heading deviations of multiple position points between the reference position point and the heading feedback pre-anchor point, thereby ensuring the determined heading driving state deviation.

[0017] Optionally, performing negative feedback adjustment according to the driving state deviation to obtain a feedback steering wheel angle includes: converting the lateral driving state deviation into a corresponding heading driving state deviation according to the lateral driving state deviation and a pre-anchor distance corresponding to the lateral deviation elimination pre-anchor point; The lateral driving state deviation is converted into a corresponding heading driving state deviation, and the heading driving state deviation is input into a fuzzy PID controller to obtain the feedback steering wheel angle.

[0018] In the embodiment of the present application, the lateral driving state deviation is converted into the corresponding heading driving state deviation and input into the PID controller together with the original heading driving state deviation, so that the feedback steering wheel angle can be accurately obtained.

[0019] Optionally, determining a target steering wheel angle according to the feedforward steering wheel angle and the feedback steering wheel angle includes: Determining the actual feedforward weight corresponding to the actual curvature mean value according to the corresponding relationship between the curvature mean value and the feedforward weight; Determining the actual feedback weight corresponding to the actual curvature mean value according to the corresponding relationship between the curvature mean value and the feedback weight; A weighted sum is performed on the feedforward steering wheel angle and the corresponding feedforward weight, the feedback steering wheel angle and the corresponding feedback weight to determine the target steering wheel angle.

[0020] In an embodiment of the present application, a feedforward weight is assigned to the feedforward steering wheel angle, and at the same time, a feedback weight is assigned to the feedback steering wheel angle. Since the feedforward weight and the feedback weight are both related to the mean curvature of a certain distance ahead, the feedforward weight and the feedback weight can be reasonably set according to the mean curvature of a certain distance ahead, so that the determined target steering wheel angle can be suitable for the complex and changeable road ahead.

[0021] Optionally, the feedforward weight is positively correlated with the mean curvature; and the feedback weight is negatively correlated with the mean curvature.

[0022] In an embodiment of the present application, when the mean value of the curvature within a certain distance ahead is large, it indicates that the curve within a certain distance ahead is large. At this time, the feedforward weight can be set to a larger value and the feedback weight can be set to a smaller value. Then the target steering wheel angle mainly depends on the feedforward steering wheel angle, so that the vehicle can subsequently perform reliable trajectory tracking on a larger curve section; when the mean value of the curvature within a certain distance ahead is small, it indicates that the curve within a certain distance ahead is small. At this time, the feedforward weight can be set to a smaller value and the feedback weight can be set to a larger value. Then the target steering wheel angle mainly depends on the feedback steering wheel angle, so that the vehicle can subsequently perform reliable trajectory tracking on a smaller curve section.

[0023] In a second aspect, an embodiment of the present application provides a device for determining a steering wheel angle, the device comprising: A location acquisition unit, used to obtain the current location point; A pre-anchor point determination unit, configured to determine a feedforward pre-aiming point and a feedback pre-anchor point corresponding to the current position point in a pre-planned driving trajectory curve; a feedforward steering wheel angle determination unit, configured to determine a feedforward steering wheel angle based on the current position point, the feedforward preview point, and vehicle attribute parameters; a driving state deviation determining unit, configured to determine a driving state deviation based on the current position point and the feedback preview point; a feedback steering wheel angle determination unit, configured to perform negative feedback adjustment according to the driving state deviation to obtain a feedback steering wheel angle; The target steering wheel angle determination unit is configured to determine a target steering wheel angle according to the feedforward steering wheel angle and the feedback steering wheel angle.

[0024] Optionally, the pre-anchor point determination unit includes: a reference position point determining unit, configured to determine a reference position point in the driving trajectory curve that matches the current position point; A feedforward / feedback pre-anchor point determination unit is used to determine the feedforward pre-aiming point and the feedback pre-anchor point corresponding to the reference position point in the driving trajectory curve.

[0025] Optionally, the feedforward / feedback pre-anchor point determination unit includes: A vehicle speed acquisition unit, used to obtain the current vehicle speed; a maximum curvature point acquisition unit, configured to acquire the maximum curvature and the corresponding maximum curvature position point in the driving trajectory curve; a candidate pre-anchor distance determining unit, configured to determine a first candidate pre-anchor distance according to the current vehicle speed and the first pre-anchor time length; The candidate pre-anchor distance determining unit is further configured to determine a second candidate pre-anchor distance based on the reference position point and the maximum curvature position point in response to the maximum curvature being greater than a set curvature threshold; a feedforward pre-anchor distance determining unit, configured to determine a feedforward pre-anchor distance based on the first candidate pre-anchor distance and the second candidate pre-anchor distance; A feedforward pre-anchor point determination unit is used to determine the feedforward pre-aiming point in the driving trajectory curve according to the reference position point and the feedforward pre-anchor distance.

[0026] Optionally, the feedforward / feedback pre-anchor point determination unit further includes: a curvature mean value acquisition unit, configured to acquire an actual curvature mean value of a plurality of position points within a preset distance after the reference position point in the driving trajectory curve; The candidate pre-anchor distance determining unit is further configured to: determine, based on a correspondence between the mean curvature and the minimum pre-anchor distance, the minimum pre-anchor distance corresponding to the actual mean curvature, and use the minimum pre-anchor distance as a third candidate pre-anchor distance; The feedforward pre-anchor distance determination unit is specifically configured to: The feedforward pre-anchor distance is determined according to the first candidate pre-anchor distance, the second candidate pre-anchor distance, and the third candidate pre-anchor distance.

[0027] Optionally, the feedforward pre-anchor distance determination unit is specifically configured to: performing a smaller operation on the first candidate pre-anchor distance and the second candidate pre-anchor distance to determine a feedforward candidate pre-anchor distance; A larger operation is performed on the feedforward candidate pre-anchor distance and the third candidate pre-anchor distance to determine the feedforward pre-anchor distance.

[0028] Optionally, the feedback pre-anchor point includes a lateral feedback pre-anchor point and a heading feedback pre-anchor point, and the feedforward / feedback pre-anchor point determination unit includes: a candidate pre-anchor distance determining unit, configured to determine a fourth candidate pre-anchor distance based on the current vehicle speed and the second pre-anchor time; a lateral deviation selection pre-anchor point determination unit, configured to determine a lateral deviation selection pre-anchor point corresponding to the reference position point in the driving trajectory curve according to the third candidate pre-anchor distance and the fourth candidate pre-anchor distance; The candidate pre-anchor distance determining unit is further configured to determine a fifth candidate pre-anchor distance based on the current vehicle speed and a third pre-anchor time length, wherein the third pre-anchor time length is greater than the second pre-anchor time length; a lateral deviation elimination pre-anchor point determining unit, configured to determine, in the driving trajectory curve, a lateral deviation elimination pre-anchor point corresponding to the reference position point based on the third candidate pre-anchor distance and the fifth candidate pre-anchor distance; a lateral feedback pre-anchor point determining unit, configured to use the lateral deviation selection pre-anchor point and the lateral deviation elimination pre-anchor point as the lateral feedback pre-anchor point; The candidate pre-anchor distance determining unit is further configured to determine a sixth candidate pre-anchor distance based on the current vehicle speed and the fourth pre-anchor duration; A heading feedback pre-anchor point determining unit is configured to determine, in the driving trajectory curve, the heading feedback pre-anchor point corresponding to the reference position point according to the third candidate pre-anchor distance and the sixth candidate pre-anchor distance.

[0029] Optionally, the driving state deviation includes a lateral driving state deviation and a heading driving state deviation, and the driving state deviation determining unit is specifically configured to: Determining a lateral deviation reference position point corresponding to the lateral deviation selection pre-anchor point in the driving trajectory curve; Determining the lateral driving state deviation between the lateral deviation selection pre-anchor point and the lateral deviation reference position point; In the driving trajectory curve, the heading driving state deviation is determined according to the heading deviations of a plurality of position points between the reference position point and the heading feedback pre-anchor point.

[0030] Optionally, the feedback steering wheel angle determination unit is specifically used to: converting the lateral driving state deviation into a corresponding heading driving state deviation according to the lateral driving state deviation and a pre-anchor distance corresponding to the lateral deviation elimination pre-anchor point; The lateral driving state deviation is converted into a corresponding heading driving state deviation, and the heading driving state deviation is input into a fuzzy PID controller to obtain the feedback steering wheel angle.

[0031] Optionally, the target steering wheel angle determination unit is specifically configured to: Determining the actual feedforward weight corresponding to the actual curvature mean value according to the corresponding relationship between the curvature mean value and the feedforward weight; Determining the actual feedback weight corresponding to the actual curvature mean value according to the corresponding relationship between the curvature mean value and the feedback weight; A weighted sum is performed on the feedforward steering wheel angle and the corresponding feedforward weight, the feedback steering wheel angle and the corresponding feedback weight to determine the target steering wheel angle.

[0032] Optionally, the feedforward weight is positively correlated with the mean curvature; and the feedback weight is negatively correlated with the mean curvature.

[0033] In a third aspect, an embodiment of the present application provides an electric power steering system, which includes a memory for storing computer program instructions and a processor for executing program instructions, wherein when the computer program instructions are executed by the processor, the electric power steering system is triggered to execute the steps of the method described in any embodiment of the first aspect.

[0034] In a fourth aspect, an embodiment of the present application provides a vehicle, which includes the electric power steering system in the embodiment of the third aspect.

[0035] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium, which is used to store computer instructions. When the computer is running, the computer instructions enable the computer to execute the steps of the method described in any embodiment of the first aspect.

[0036] It should be understood that the second to fifth aspects of the embodiments of the present application are consistent with the technical solutions of the first aspect of the embodiments of the present application, and the beneficial effects achieved by each aspect and the corresponding feasible implementation methods are similar and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0038] Figure 1 A schematic flow chart of a method for determining a steering wheel angle provided in an embodiment of the present application; Figure 2 A flow chart of a method for determining a feedforward pre-anchor point and a feedback pre-anchor point provided in an embodiment of the present application; Figure 3 A schematic diagram of a flow chart of a method for determining a feedforward pre-anchor point provided in an embodiment of the present application; Figure 4 A flowchart of another method for determining a feedforward pre-anchor point provided in an embodiment of the present application; Figure 5 A schematic diagram of a flow chart of a method for determining a feedforward pre-anchor distance provided in an embodiment of the present application; Figure 6 A schematic diagram of determining a vehicle feedforward steering wheel angle provided in an embodiment of the present application; Figure 7 A flowchart of a method for determining a feedback pre-anchor point provided in an embodiment of the present application; Figure 8 A flowchart of a method for determining a driving state deviation provided in an embodiment of the present application; Figure 9 A schematic diagram of a flow chart of a method for obtaining a feedback steering wheel angle provided in an embodiment of the present application; Figure 10 A schematic flow chart of a method for determining a target steering wheel angle provided in an embodiment of the present application; Figure 11 A schematic structural diagram of a device for determining a steering wheel angle provided in an embodiment of the present application; Figure 12A schematic structural diagram of an electric power steering system provided in an embodiment of the present application; Figure 13 A schematic structural diagram of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] In order to better understand the technical solutions of this specification, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0040] It should be clear that the embodiments described are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this specification.

[0041] The terms used in the examples of this application are for the purpose of describing specific embodiments only and are not intended to limit this specification. The singular forms "a," "an," "the," and "the" used in the examples of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0042] With the rapid development of intelligent driving technology, vehicle trajectory tracking has become a crucial component in achieving autonomous driving. This technology requires intelligent vehicles to accurately and stably follow pre-planned trajectories, whether on straight roads, curved roads, or in complex and changing road environments. To achieve this goal, accurately determining the steering wheel angle under complex and changing road conditions is a pressing challenge.

[0043] In view of this, an embodiment of the present application provides a method for determining a steering wheel angle. In this method, a feedforward steering wheel angle that can cope with the complex and changeable road ahead, and a feedback steering wheel angle that can correct the deviation between the vehicle's actual driving trajectory and the preset driving trajectory are determined. On this basis, the target steering wheel angle is determined jointly by the feedforward steering wheel angle and the feedback steering wheel angle. The target steering wheel angle then combines the characteristics of the feedforward steering wheel angle and the feedback steering wheel angle, thereby enabling the vehicle to achieve reliable trajectory tracking.

[0044] The technical solution protected by this application is described in detail below with reference to the accompanying drawings.

[0045] See Figure 1 , is a flow chart of a method for determining a steering wheel angle provided in an embodiment of the present application. The method is applied to an Electric Power Steering (EPS) system. The flow of the method is described as follows: Step 101: Get the current location.

[0046] In an embodiment of the present application, the vehicle can obtain the current position point in real time during driving. It should be understood that the current position point here can be considered as the current position coordinates. For example, the current position point obtained is (X1, Y1), where X1 can represent longitude and Y1 can represent latitude.

[0047] Step 102: Determine the feedforward pre-aiming point and feedback pre-anchor point corresponding to the current position point in the pre-planned driving trajectory curve.

[0048] In an embodiment of the present application, before the vehicle starts driving, the navigation application can pre-plan a corresponding driving trajectory curve based on the starting point and end point input by the user, and then determine the feedforward pre-anchor point and feedback pre-anchor point corresponding to the current position point from the driving trajectory curve.

[0049] In some embodiments, considering that the actual driving trajectory of the vehicle may not be consistent with the pre-planned driving trajectory, the current position of the vehicle may not be on the pre-planned driving trajectory curve. If the current position is directly used as a reference to find the feedforward pre-anchor point and the feedback pre-anchor point on the pre-planned driving trajectory curve, the accuracy may be poor.

[0050] See Figure 2 , which is a flow chart of a method for determining a feedforward pre-anchor point and a feedback pre-anchor point provided in an embodiment of the present application. Step 102 can be implemented by executing sub-steps 1021 to 1022: Step 1021: Determine a reference position point in the driving trajectory curve that matches the current position point.

[0051] Step 1022: Determine the feedforward pre-aiming point and the feedback pre-anchor point corresponding to the reference position point in the driving trajectory curve.

[0052] In an embodiment of the present application, a reference position point that matches the current position point can be determined on the pre-planned driving trajectory curve, and then the feedforward pre-anchor point and the feedback pre-anchor point can be more accurately determined based on the reference position point.

[0053] For example, the pre-planned driving trajectory curve can be considered to be composed of a large number of discrete position points. Then the relative distance between the current position point and each discrete position point in the pre-planned driving trajectory curve can be calculated, and then the discrete position point with the smallest relative distance is used as the position point matching the current position point, that is, the reference position point.

[0054] For another example, an objective function based on the relative distance between the current location and any point on the pre-planned driving trajectory can be constructed, and then the reference location can be determined with the goal of minimizing the objective function. Of course, the reference location can also be determined by other methods, and this application does not impose any particular restrictions on this.

[0055] The following describes in detail how to determine the feedforward pre-anchor point and the feedback pre-anchor point.

[0056] First: determine the feedforward pre-anchor point.

[0057] See Figure 3 , which is a flow chart of a method for determining a feedforward pre-anchor point according to an embodiment of the present application. Step 1022 can be implemented by executing sub-steps 201 to 205: Step 201: Obtain the current vehicle speed, and obtain the maximum curvature in the driving trajectory curve and the corresponding maximum curvature position point.

[0058] Step 202: Determine a first candidate pre-anchor distance based on the current vehicle speed and the first pre-anchor duration.

[0059] Step 203: In response to the maximum curvature being greater than the set curvature threshold, a second candidate pre-anchor distance is determined based on the reference position point and the maximum curvature position point.

[0060] Step 204: Determine a feedforward pre-anchor distance based on the first candidate pre-anchor distance and the second candidate pre-anchor distance.

[0061] Step 205: In the driving trajectory curve, determine the feedforward pre-aiming point according to the reference position point and the feedforward pre-anchor distance.

[0062] In this embodiment, without considering road variations, a first candidate pre-anchor distance is initially determined based on the current vehicle speed and the first pre-anchor duration. Taking road variations into account, if a significant curve appears at a certain point on the road ahead, a second candidate pre-anchor distance is determined based on the reference position and the location of the significant curve. Finally, the feedforward pre-anchor distance is accurately determined based on the first and second candidate pre-anchor distances, and the corresponding feedforward pre-anchor point is then determined.

[0063] In some embodiments, if the selected feedforward pre-anchor point is close to the reference position point, the subsequently calculated feedforward steering wheel angle may be too large, or the feedforward steering wheel angles calculated in adjacent cycles may differ greatly, making it impossible to control the vehicle well.

[0064] See Figure 4 , which is a flow chart of another method for determining a feedforward pre-anchor point provided by an embodiment of the present application. Before executing step 204, you can also continue to execute steps 301 to 302: Step 301: Obtain the actual curvature average of multiple position points within a preset distance after a reference position point in the driving trajectory curve.

[0065] Step 302: According to the correspondence between the mean curvature and the minimum pre-anchor distance, the minimum pre-anchor distance corresponding to the actual mean curvature is determined and used as the third candidate pre-anchor distance.

[0066] In the embodiment of the present application, the corresponding relationship between the mean curvature and the minimum pre-anchor distance is shown in Table 1: Table 1

[0067] It can be seen from Table 1 that within a certain range of curvature mean values, there is a negative correlation between the curvature mean value and the minimum pre-anchor distance, that is, the larger the curvature mean value, the smaller the minimum pre-anchor distance; conversely, the smaller the curvature mean value, the larger the minimum pre-anchor distance.

[0068] For example, if the mean curvature of multiple discrete points within 4 meters of the reference position is 0.05, then according to Table 1, the minimum pre-anchor distance is 3 meters, that is, the third candidate pre-anchor distance is 3 meters.

[0069] Step 204 can be specifically implemented by executing sub-step 303: Step 303: Determine a feedforward pre-anchor distance according to the first candidate pre-anchor distance, the second candidate pre-anchor distance, and the third candidate pre-anchor distance.

[0070] In an embodiment of the present application, before determining the feedforward pre-anchor distance, the corresponding minimum pre-anchor distance can be determined based on the curvature mean of multiple position points within a preset distance after the reference position point, and the minimum pre-anchor distance is used as the third candidate pre-anchor distance. Then, the feedforward pre-anchor distance is determined from the first candidate pre-anchor distance, the second candidate pre-anchor distance and the third candidate pre-anchor distance, so as to avoid the determined feedforward pre-anchor distance being too small.

[0071] See Figure 5 , which is a flow chart of a method for determining a feedforward pre-anchor distance provided in an embodiment of the present application. Step 303 can be implemented by executing sub-steps 3031 to 3032: Step 3031: perform a smaller operation on the first candidate pre-anchor distance and the second candidate pre-anchor distance to determine the feedforward candidate pre-anchor distance.

[0072] Step 3032: Perform a larger operation on the feedforward candidate pre-anchor distance and the third candidate pre-anchor distance to determine the feedforward pre-anchor distance.

[0073] In an embodiment of the present application, by performing a smaller operation on the first candidate pre-anchor distance and the second candidate pre-anchor distance, the determined feedforward candidate pre-anchor distance can be made applicable to the complex and changeable roads ahead; on this basis, the feedforward candidate pre-anchor distance and the third candidate pre-anchor distance are maximized, that is, when the feedforward candidate pre-anchor distance is less than the third candidate pre-anchor distance, the third candidate pre-anchor distance is used as the feedforward pre-anchor distance; conversely, when the feedforward candidate pre-anchor distance is greater than the third candidate pre-anchor distance, the feedforward candidate pre-anchor distance is used as the feedforward pre-anchor distance, which can avoid making the determined feedforward pre-anchor distance too small, and can also be applicable to the complex and changeable roads ahead.

[0074] Step 103: Determine the feedforward steering wheel angle according to the current position point, the feedforward preview point and the vehicle attribute parameters.

[0075] In the embodiment of the present application, the vehicle attribute parameters include the wheelbase (L) and the front wheel angle transmission ratio (Ratio). The following describes in detail how to determine the feedforward steering wheel angle.

[0076] See Figure 6 , is a schematic diagram of determining a vehicle feedforward steering wheel angle provided by an embodiment of the present application. Figure 6 As shown, the position point of the vehicle's rear wheel is A, the position point of the vehicle's front wheel is B, and the longitudinal body of the vehicle is the tangent. By controlling the front wheel steering angle, the vehicle's rear wheel A can travel along an arc passing through the feedforward pre-anchor point C. Line segment AC represents the line between the rear wheel position point A and the feedforward pre-anchor point C.

[0077] Because △AOC is an isosceles triangle, in △AOB, AB⊥OA, then ∠AOC is as shown in formula (1): (1) Where α represents the angle between the longitudinal body tangent and line segment AC In order to make the rear wheel of the vehicle track the arc dotted line trajectory to reach the feedforward pre-anchor point C, the sine theorem relationship that needs to be satisfied in △AOC is shown in formula (2): (2) Among them, R represents the radius of the vehicle's rear wheel when it follows the arc dotted line trajectory, l d Represents the length of line segment AC.

[0078] Simplifying the above formula (2), we can get formula (3): (3) According to the relationship between radius R and curvature k, formula (3) can be further converted into formula (4): (4) Wherein, k represents the curvature of the rear wheel of the vehicle when tracking the arc dotted line trajectory.

[0079] Since the current position point A of the rear wheel and the position coordinates of the feedforward pre-anchor point C are known, l can be calculated. d At the same time, within △ACD, the angle α can be calculated by the inverse tangent function. On this basis, l d Substituting α into formula (4), the curvature k can be calculated.

[0080] The calculation formula of the front wheel angle is shown in (5): (5) in, represents the front wheel turning angle, and L represents the vehicle wheelbase.

[0081] At a known front wheel angle , can be combined with the front wheel angle transmission ratio The feedforward steering wheel angle is determined as shown in formula (6): (6) in, represents the feedforward steering wheel angle.

[0082] Second: Determine the feedback pre-anchor point See Figure 7 , which is a flow chart of a method for determining a feedback pre-anchor point according to an embodiment of the present application. Step 1022 can be implemented by executing sub-steps 206 to 212: Step 206: Determine a fourth candidate pre-anchor distance based on the current vehicle speed and the second pre-anchor time.

[0083] In the embodiment of the present application, the product of the current vehicle speed and the second pre-anchor time length can be calculated to determine the fourth candidate pre-anchor distance.

[0084] Step 207: Determine the lateral deviation corresponding to the reference position point in the driving trajectory curve according to the third candidate pre-anchor distance and the fourth candidate pre-anchor distance, and select a pre-anchor point.

[0085] In this embodiment of the present application, since the third candidate pre-anchor distance is the minimum pre-anchor distance corresponding to the mean curvature within a preset distance from the reference position, a larger operation can be performed on the third candidate pre-anchor distance and the fourth candidate pre-anchor distance. That is, when the third candidate pre-anchor distance is greater than the fourth candidate pre-anchor distance, the result of the larger operation is the third candidate pre-anchor distance; conversely, when the third candidate pre-anchor distance is less than the fourth candidate pre-anchor distance, the result of the larger operation is the fourth candidate pre-anchor distance. The lateral deviation pre-anchor point corresponding to the reference position is then determined in the driving trajectory curve based on the result of this larger operation. This avoids the situation where the determined lateral deviation pre-anchor point is too close to the reference position, which could lead to inaccurate lateral deviations subsequently determined based on the lateral deviation pre-anchor point.

[0086] It should be noted that when the third candidate pre-anchor distance is greater than the fourth candidate pre-anchor distance, in addition to determining the lateral deviation selection pre-anchor point by taking the larger operation, the lateral deviation selection pre-anchor point can also be determined based on the sum of the third candidate pre-anchor distance and the fourth candidate pre-anchor distance; conversely, when the third candidate pre-anchor distance is less than the fourth candidate pre-anchor distance, in addition to determining the lateral deviation selection pre-anchor point by taking the larger operation, the lateral deviation selection pre-anchor point can also be determined based on the sum of the third candidate pre-anchor distance and the fourth candidate pre-anchor distance, or, the lateral deviation selection pre-anchor point can be determined based on the average value of the third candidate pre-anchor distance and the fourth candidate pre-anchor distance.

[0087] Step 208: Determine a fifth candidate pre-anchor distance based on the current vehicle speed and the third pre-anchor time, wherein the third pre-anchor time is greater than the second pre-anchor time.

[0088] In this embodiment of the present application, the product of the current vehicle speed and the third pre-anchor duration can be calculated to determine the fifth candidate pre-anchor distance. Since the third pre-anchor duration is greater than the second pre-anchor duration, the fifth candidate pre-anchor distance should be greater than the fourth candidate pre-anchor distance.

[0089] Step 209: Determine a lateral deviation elimination pre-anchor point corresponding to the reference position point in the driving trajectory curve according to the third candidate pre-anchor distance and the fifth candidate pre-anchor distance.

[0090] In this embodiment of the present application, since the third candidate pre-anchor distance is the minimum pre-anchor distance corresponding to the mean curvature within a preset distance from the reference position, a larger operation can be performed on the third candidate pre-anchor distance and the fifth candidate pre-anchor distance. That is, when the third candidate pre-anchor distance is greater than the fifth candidate pre-anchor distance, the larger operation results in the third candidate pre-anchor distance; conversely, when the third candidate pre-anchor distance is less than the fifth candidate pre-anchor distance, the larger operation results in the fifth candidate pre-anchor distance. The lateral deviation elimination pre-anchor point corresponding to the reference position is then determined within the driving trajectory curve based on the larger operation result. This avoids the situation where the determined lateral deviation elimination pre-anchor point is too close to the reference position, requiring urgent correction of the vehicle's lateral deviation within a shorter distance.

[0091] It should be noted that, based on the known third candidate pre-anchor distance and the fifth candidate pre-anchor distance, the lateral deviation elimination pre-anchor point can be determined by other methods, which can be referred to step 207 and will not be described in detail here.

[0092] Step 210: The lateral deviation selection pre-anchor point and the lateral deviation elimination pre-anchor point are used as lateral feedback pre-anchor points.

[0093] Step 211: Determine a sixth candidate pre-anchor distance based on the current vehicle speed and the fourth pre-anchor duration.

[0094] In the embodiment of the present application, the product of the current vehicle speed and the fourth pre-anchor time length can be calculated to determine the sixth candidate pre-anchor distance.

[0095] Step 212: Determine a heading feedback pre-anchor point corresponding to the reference position point in the driving trajectory curve according to the third candidate pre-anchor distance and the sixth candidate pre-anchor distance.

[0096] In this embodiment of the present application, since the third candidate pre-anchor distance is the minimum pre-anchor distance corresponding to the mean curvature within a preset distance from the reference position, a larger operation can be performed on the third candidate pre-anchor distance and the sixth candidate pre-anchor distance. That is, when the third candidate pre-anchor distance is greater than the sixth candidate pre-anchor distance, the larger operation results in the third candidate pre-anchor distance; conversely, when the third candidate pre-anchor distance is less than the sixth candidate pre-anchor distance, the larger operation results in the sixth candidate pre-anchor distance. The heading feedback pre-anchor point corresponding to the reference position is then determined in the driving trajectory curve based on the larger operation result, thereby avoiding the situation where the determined heading feedback pre-anchor point is too close to the reference position, which would result in a lower accuracy of the heading deviation subsequently determined based on the heading feedback pre-anchor point.

[0097] It should be noted that, based on the known third candidate pre-anchor distance and the sixth candidate pre-anchor distance, the lateral deviation elimination pre-anchor point can be determined by other methods, which can be referred to step 207 and will not be described in detail here.

[0098] Step 104: Determine the driving state deviation based on the current position point and the feedback preview point.

[0099] In the embodiment of the present application, the driving state deviation includes a lateral driving state deviation and a heading driving state deviation. The following is a detailed description of how to determine the driving state deviation.

[0100] See Figure 8 , which is a flow chart of a method for determining a driving state deviation provided in an embodiment of the present application. Step 104 can be implemented by executing sub-steps 1041 to 1043: Step 1041: Determine a lateral deviation reference position point corresponding to a lateral deviation selection pre-anchor point in the driving trajectory curve.

[0101] In the embodiment of the present application, the method of determining the reference position point of the current position point in the driving trajectory curve mentioned above can be referred to to determine the lateral deviation reference position point corresponding to the lateral deviation selection pre-anchor point, which will not be repeated here.

[0102] Step 1042: Determine the lateral driving state deviation between the lateral deviation selection pre-anchor point and the lateral deviation reference position point.

[0103] Step 1043: In the driving trajectory curve, determine the heading driving state deviation according to the heading deviations of multiple position points between the reference position point and the heading feedback pre-anchor point.

[0104] In the embodiment of the present application, the average value of the heading deviations of multiple position points between the reference position point and the heading feedback pre-anchor point can be calculated as the heading driving state deviation.

[0105] Step 105: Perform negative feedback adjustment according to the driving state deviation to obtain a feedback steering wheel angle.

[0106] In the embodiment of the present application, negative feedback adjustment is performed for the purpose of minimizing the driving state deviation (lateral driving state deviation and heading driving state deviation), so that the feedback steering wheel angle can be obtained.

[0107] It should be noted that the lateral driving state deviation and the heading driving state deviation are two independent parameters.

[0108] In some embodiments, the heading driving state deviation may be converted into the heading driving state deviation to participate in the above-mentioned negative feedback regulation.

[0109] See Figure 9 , which is a flow chart of a method for obtaining a feedback steering wheel angle according to an embodiment of the present application. Step 105 can be implemented by executing sub-steps 1051 to 1052: Step 1051: According to the lateral driving state deviation and the pre-anchor distance corresponding to the lateral deviation elimination pre-anchor point, the lateral driving state deviation is converted into a corresponding heading driving state deviation.

[0110] Step 1052: Convert the lateral driving state deviation into the corresponding heading driving state deviation, and input the heading driving state deviation into the fuzzy PID controller to obtain a feedback steering wheel angle.

[0111] In the embodiment of the present application, the lateral driving state deviation is converted into the corresponding heading driving state deviation, as shown in formula (7): (7) in, Indicates the lateral driving state deviation, represents the lateral deviation elimination pre-anchor distance, that is, the larger operation result between the third candidate pre-anchor distance and the fifth candidate pre-anchor distance, Indicates the corresponding heading driving state deviation after the lateral driving state deviation is converted.

[0112] After converting the lateral driving state deviation into the corresponding heading driving state deviation, it is input into the PID controller together with the original heading driving state deviation to accurately obtain the feedback steering wheel angle.

[0113] Step 106: Determine a target steering wheel angle according to the feedforward steering wheel angle and the feedback steering wheel angle.

[0114] In the embodiments of the present application, on the one hand, the steering wheel angle required to smoothly pass the complex and changeable road ahead (i.e., the feedforward steering wheel angle) is predicted in advance. This advance response mechanism enables the vehicle to prepare for steering before reaching a specific position, avoiding trajectory deviation caused by reaction lag, and helping to achieve smoother and more accurate trajectory tracking. On the other hand, the steering wheel angle used to correct the deviation between the vehicle's actual driving trajectory and the preset driving trajectory (i.e., the feedback steering wheel angle) is calculated in real time. This ability to correct the deviation in real time makes the feedback control highly robust to various uncertainties and unmodeled dynamics, and can ensure that the vehicle tracks the desired trajectory as closely as possible under complex and changeable road conditions. Therefore, the target steering wheel angle determined based on the feedforward steering wheel angle and the feedback steering wheel angle can be considered to have the respective characteristics of the feedforward steering wheel angle and the feedback steering wheel angle, thereby achieving reliable vehicle trajectory tracking.

[0115] In some embodiments, considering that the target steering wheel angle is jointly determined by the feedforward steering wheel angle and the feedback steering wheel angle, and under different road conditions, the respective advantages of the feedforward steering wheel angle and the feedback steering wheel angle are different, therefore, in an embodiment of the present application, different degrees of influence can be given to the feedforward steering wheel angle and the feedback steering wheel angle under different road conditions, so that under certain road conditions, the size of the target steering wheel angle mainly depends on the feedforward steering wheel angle, so that it can respond in advance; under certain road conditions, the size of the target steering wheel angle mainly depends on the feedback steering wheel angle, so that it can correct the deviation in real time.

[0116] See Figure 10 , which is a flow chart of a method for determining a target steering wheel angle provided in an embodiment of the present application. Step 106 can be implemented by executing sub-steps 1061 to 1063: Step 1061: According to the corresponding relationship between the mean curvature value and the feedforward weight, determine the actual feedforward weight corresponding to the actual mean curvature value.

[0117] Step 1062: According to the corresponding relationship between the mean curvature value and the feedback weight, determine the actual feedback weight corresponding to the actual mean curvature value.

[0118] Step 1063: Perform weighted summation on the feedforward steering wheel angle and the corresponding actual feedforward weight, the feedback steering wheel angle and the corresponding actual feedback weight to determine the target steering wheel angle.

[0119] In an embodiment of the present application, a feedforward weight is assigned to the feedforward steering wheel angle, and at the same time, a feedback weight is assigned to the feedback steering wheel angle. Since the feedforward weight and the feedback weight are both related to the mean curvature of a certain distance ahead, the feedforward weight and the feedback weight can be reasonably set according to the mean curvature of a certain distance ahead, so that the determined target steering wheel angle can be suitable for the complex and changeable road ahead.

[0120] The corresponding relationship between the feedforward weight and the curvature mean is shown in Table 2:

[0121] The corresponding relationship between feedback weight and curvature mean is shown in Table 3:

[0122] As shown in Table 2, within a certain range, the feedforward weight and the mean curvature are positively correlated. As shown in Table 3, within a certain range, the feedback weight and the mean curvature are negatively correlated. Specifically, when the mean curvature within a certain distance ahead is large, it indicates a larger curve ahead. In this case, the feedforward weight can be set larger and the feedback weight smaller. The target steering wheel angle then primarily depends on the feedforward steering wheel angle, allowing the vehicle to maneuver in advance and subsequently ensure reliable trajectory tracking on larger curves. When the mean curvature within a certain distance ahead is small, it indicates a smaller curve ahead. In this case, the feedforward weight can be set smaller and the feedback weight larger. The target steering wheel angle then primarily depends on the feedback steering wheel angle, allowing the vehicle to subsequently rely primarily on corrective action on smaller curves for reliable trajectory tracking.

[0123] See Figure 11 , is a schematic diagram of the structure of a device for determining a steering wheel angle provided in an embodiment of the present application. The device includes: Position acquisition unit 401, used to acquire the current position point; A pre-anchor point determination unit 402 is used to determine a feedforward pre-aiming point and a feedback pre-anchor point corresponding to the current position point in the pre-planned driving trajectory curve; A feedforward steering wheel angle determination unit 403 is configured to determine a feedforward steering wheel angle based on the current position point, the feedforward preview point, and vehicle attribute parameters; A driving state deviation determining unit 404 is configured to determine a driving state deviation based on the current position point and the feedback preview point; A feedback steering wheel angle determination unit 405 is configured to perform negative feedback adjustment according to a driving state deviation to obtain a feedback steering wheel angle; The target steering wheel angle determination unit 406 is configured to determine a target steering wheel angle according to the feedforward steering wheel angle and the feedback steering wheel angle.

[0124] Optionally, the pre-anchor point determining unit 402 includes: a reference position point determining unit, configured to determine a reference position point in the driving trajectory curve that matches the current position point; A feedforward / feedback pre-anchor point determination unit is used to determine the feedforward pre-aiming point and the feedback pre-anchor point corresponding to the reference position point in the driving trajectory curve.

[0125] Optionally, a feedforward / feedback pre-anchor point determination unit includes: A vehicle speed acquisition unit, used to obtain the current vehicle speed; A maximum curvature point acquisition unit is used to obtain the maximum curvature in the driving trajectory curve and the corresponding maximum curvature position point; a candidate pre-anchor distance determining unit, configured to determine a first candidate pre-anchor distance based on a current vehicle speed and a first pre-anchor duration; The candidate pre-anchor distance determining unit is further configured to determine a second candidate pre-anchor distance based on the reference position point and the maximum curvature position point in response to the maximum curvature being greater than a set curvature threshold; a feedforward pre-anchor distance determining unit, configured to determine a feedforward pre-anchor distance based on the first candidate pre-anchor distance and the second candidate pre-anchor distance; The feedforward pre-anchor point determination unit is used to determine the feedforward pre-aiming point in the driving trajectory curve according to the reference position point and the feedforward pre-anchor distance.

[0126] Optionally, the feedforward / feedback pre-anchor point determination unit further includes: a curvature mean value acquisition unit, configured to acquire an actual curvature mean value of a plurality of position points within a preset distance after a reference position point in a driving trajectory curve; The candidate pre-anchor distance determining unit is further configured to: determine, based on a correspondence between the mean curvature and the minimum pre-anchor distance, the minimum pre-anchor distance corresponding to the actual mean curvature, and use the minimum pre-anchor distance as the third candidate pre-anchor distance; The feedforward pre-anchor distance determination unit is specifically used to: The feedforward pre-anchor distance is determined according to the first candidate pre-anchor distance, the second candidate pre-anchor distance, and the third candidate pre-anchor distance.

[0127] Optionally, the feedforward pre-anchor distance determination unit is specifically configured to: Taking the smaller of the first candidate pre-anchor distance and the second candidate pre-anchor distance to determine the feedforward candidate pre-anchor distance; The feedforward candidate pre-anchor distance and the third candidate pre-anchor distance are taken to be larger to determine the feedforward pre-anchor distance.

[0128] Optionally, the feedback pre-anchor point includes a lateral feedback pre-anchor point and a heading feedback pre-anchor point, and the feedforward / feedback pre-anchor point determination unit includes: a candidate pre-anchor distance determining unit, configured to determine a fourth candidate pre-anchor distance based on the current vehicle speed and the second pre-anchor time duration; a lateral deviation selection pre-anchor point determination unit, configured to determine a lateral deviation selection pre-anchor point corresponding to a reference position point in a driving trajectory curve according to a third candidate pre-anchor distance and a fourth candidate pre-anchor distance; The candidate pre-anchor distance determining unit is further configured to determine a fifth candidate pre-anchor distance based on the current vehicle speed and the third pre-anchor time length, wherein the third pre-anchor time length is greater than the second pre-anchor time length; a lateral deviation elimination pre-anchor point determining unit, configured to determine a lateral deviation elimination pre-anchor point corresponding to a reference position point in a driving trajectory curve based on the third candidate pre-anchor distance and the fifth candidate pre-anchor distance; a lateral feedback pre-anchor point determination unit, configured to use the lateral deviation selection pre-anchor point and the lateral deviation elimination pre-anchor point as lateral feedback pre-anchor points; The candidate pre-anchor distance determining unit is further configured to determine a sixth candidate pre-anchor distance based on the current vehicle speed and the fourth pre-anchor time duration; The heading feedback pre-anchor point determination unit is used to determine a heading feedback pre-anchor point corresponding to the reference position point in the driving trajectory curve according to the third candidate pre-anchor distance and the sixth candidate pre-anchor distance.

[0129] Optionally, the driving state deviation includes a lateral driving state deviation and a heading driving state deviation, and the driving state deviation determining unit 404 is specifically configured to: Determining a lateral deviation reference position point corresponding to a lateral deviation selection pre-anchor point in the driving trajectory curve; Determine the lateral driving state deviation between the lateral deviation selection pre-anchor point and the lateral deviation reference position point; In the driving trajectory curve, the heading driving state deviation is determined based on the heading deviations of multiple position points between the reference position point and the heading feedback pre-anchor point.

[0130] Optionally, the feedback steering wheel angle determination unit 405 is specifically configured to: According to the lateral driving state deviation and the pre-anchor distance corresponding to the pre-anchor point of the lateral deviation elimination, the lateral driving state deviation is converted into the corresponding heading driving state deviation; The lateral driving state deviation is converted into the corresponding heading driving state deviation, and the heading driving state deviation is input into the fuzzy PID controller to obtain the feedback steering wheel angle.

[0131] Optionally, the target steering wheel angle determination unit 406 is specifically configured to: According to the corresponding relationship between the mean curvature and the feedforward weight, the actual feedforward weight corresponding to the actual curvature mean is determined; According to the corresponding relationship between the mean curvature value and the feedback weight, the actual feedback weight corresponding to the actual mean curvature value is determined; The target steering wheel angle is determined by performing a weighted summation of the feedforward steering wheel angle and the corresponding feedforward weight, the feedback steering wheel angle and the corresponding feedback weight.

[0132] Optionally, the feedforward weight is positively correlated with the mean curvature; and the feedback weight is negatively correlated with the mean curvature.

[0133] See Figure 12 , a schematic structural diagram of an electric power steering system provided in an embodiment of the present application, the electric power steering system includes at least one processor 501, the processor 501 is used to execute a computer program stored in a memory, and implement the embodiment of the present application as provided in the following Figure 1-Figure 5 or Figure 7-10 Schematic flow chart of the method for determining the steering wheel angle shown.

[0134] Optionally, the processor 501 may specifically be a central processing unit, a specific ASIC, or one or more integrated circuits for controlling program execution.

[0135] Optionally, the electric power steering system may further include a memory 502 connected to the at least one processor 501. The memory 502 may include ROM, RAM, and disk storage. The memory 502 is used to store data required by the processor 501 when it is running, that is, it stores instructions that can be executed by the at least one processor 501. The at least one processor 501 executes the instructions stored in the memory 502 to execute the following steps: Figure 1-Figure 5 or Figure 7-10 The method shown in FIG. 1 . The number of the memory 502 is one or more. The number of the memory 502 is one or more.

[0136] See Figure 13 The embodiment of the present application further provides a vehicle, which at least includes Figure 12 The electric power steering system shown, the vehicle can be a pure electric vehicle, a plug-in hybrid vehicle, or an extended-range vehicle.

[0137] The embodiment of the present application also provides a computer storage medium, wherein the computer storage medium stores computer instructions, which, when executed on a computer, cause the computer to execute the following Figure 1-Figure 5 or Figure 7-10 method.

[0138] The computer-readable storage medium may be any combination of one or more computer-readable media. The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: an electrical connection having one or more conductors, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM) or flash memory, optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0139] A computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, which carries computer-readable program code. Such a propagated data signal may take a variety of forms, including, but not limited to, electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transport a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0140] Program code embodied on a computer-readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, radio frequency (RF), etc., or any suitable combination of the foregoing.

[0141] Computer program code for performing the operations of this specification may be written in one or more programming languages, or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may execute entirely on the user's computer, partially on the user's computer, as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on the remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., through the Internet using an Internet service provider).

[0142] The foregoing description of this specification describes specific embodiments. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in an order different from that described in the embodiments and still achieve the desired results. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the specific order shown or the sequential order to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0143] In the several embodiments provided in this specification, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed may be through some interface, indirect coupling or communication connection of devices or units, which may be electrical, mechanical or other forms.

[0144] In addition, the functional units in the various embodiments of this specification may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or hardware plus software functional units.

[0145] The above description is only a preferred embodiment of this specification and is not intended to limit this specification. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this specification should be included in the scope of protection of this specification.

Claims

1. A method for determining a steering wheel angle, characterized in that: The method comprises: Get the current location; Determining a feedforward pre-aiming point and a feedback pre-anchor point corresponding to the current position point in a pre-planned driving trajectory curve; Determining a feedforward steering wheel angle according to the current position point, the feedforward preview point, and vehicle attribute parameters; Determining a driving state deviation based on the current position point and the feedback preview point; Performing negative feedback adjustment according to the driving state deviation to obtain a feedback steering wheel angle; A target steering wheel angle is determined according to the feedforward steering wheel angle and the feedback steering wheel angle.

2. The method according to claim 1, characterized in that Determining a feedforward pre-aiming point and a feedback pre-anchor point corresponding to the current position point in a pre-planned driving trajectory curve includes: Determining a reference position point in the driving trajectory curve that matches the current position point; The feedforward pre-aiming point and the feedback pre-anchor point corresponding to the reference position point are determined in the driving trajectory curve.

3. The method according to claim 2, characterized in that Determining the feedforward preview point corresponding to the reference position point in the driving trajectory curve includes: Obtaining the current vehicle speed, and obtaining the maximum curvature of the driving trajectory curve and the corresponding maximum curvature position point; Determining a first candidate pre-anchor distance according to the current vehicle speed and the first pre-anchor time; In response to the maximum curvature being greater than a set curvature threshold, determining a second candidate pre-anchor distance according to the reference position point and the maximum curvature position point; Determining a feedforward pre-anchor distance based on the first candidate pre-anchor distance and the second candidate pre-anchor distance; In the driving trajectory curve, the feedforward pre-aiming point is determined according to the reference position point and the feedforward pre-anchor distance.

4. The method according to claim 3, characterized in that Before determining a feedforward pre-anchor distance based on the first candidate pre-anchor distance and the second candidate pre-anchor distance, the method includes: Obtaining an average value of actual curvature of a plurality of position points within a preset distance after the reference position point in the driving trajectory curve; According to the correspondence between the mean curvature and the minimum pre-anchor distance, the minimum pre-anchor distance corresponding to the actual mean curvature is determined and used as the third candidate pre-anchor distance; Determining a feedforward pre-anchor distance according to the first candidate pre-anchor distance and the second candidate pre-anchor distance includes: The feedforward pre-anchor distance is determined according to the first candidate pre-anchor distance, the second candidate pre-anchor distance, and the third candidate pre-anchor distance.

5. The method according to claim 4, characterized in that Determining the feedforward pre-anchor distance according to the first candidate pre-anchor distance, the second candidate pre-anchor distance, and the third candidate pre-anchor distance includes: performing a smaller operation on the first candidate pre-anchor distance and the second candidate pre-anchor distance to determine a feedforward candidate pre-anchor distance; A larger operation is performed on the feedforward candidate pre-anchor distance and the third candidate pre-anchor distance to determine the feedforward pre-anchor distance.

6. The method according to claim 4, characterized in that The feedback pre-anchor point includes a lateral feedback pre-anchor point and a heading feedback pre-anchor point. Determining the feedback pre-anchor point corresponding to the reference position point in the driving trajectory curve includes: determining a fourth candidate pre-anchor distance based on the current vehicle speed and the second pre-anchor time; Determine the lateral deviation corresponding to the reference position point in the driving trajectory curve according to the third candidate pre-anchor distance and the fourth candidate pre-anchor distance and select a pre-anchor point; determining a fifth candidate pre-anchor distance according to the current vehicle speed and a third pre-anchor time, wherein the third pre-anchor time is greater than the second pre-anchor time; Determining a lateral deviation elimination pre-anchor point corresponding to the reference position point in the driving trajectory curve according to the third candidate pre-anchor distance and the fifth candidate pre-anchor distance; The lateral deviation selection pre-anchor point and the lateral deviation elimination pre-anchor point are used as the lateral feedback pre-anchor points; determining a sixth candidate pre-anchor distance based on the current vehicle speed and the fourth pre-anchor time; The heading feedback pre-anchor point corresponding to the reference position point is determined in the driving trajectory curve according to the third candidate pre-anchor distance and the sixth candidate pre-anchor distance.

7. The method according to claim 6, characterized in that The driving state deviation includes a lateral driving state deviation and a heading driving state deviation. The driving state deviation is determined according to the current position point and the feedback preview point, including: Determining a lateral deviation reference position point corresponding to the lateral deviation selection pre-anchor point in the driving trajectory curve; Determining the lateral driving state deviation between the lateral deviation selection pre-anchor point and the lateral deviation reference position point; In the driving trajectory curve, the heading driving state deviation is determined according to the heading deviations of a plurality of position points between the reference position point and the heading feedback pre-anchor point.

8. The method according to claim 7, characterized in that Performing negative feedback adjustment according to the driving state deviation to obtain a feedback steering wheel angle includes: converting the lateral driving state deviation into a corresponding heading driving state deviation according to the lateral driving state deviation and a pre-anchor distance corresponding to the lateral deviation elimination pre-anchor point; The lateral driving state deviation is converted into a corresponding heading driving state deviation, and the heading driving state deviation is input into a fuzzy PID controller to obtain the feedback steering wheel angle.

9. The method according to claim 4, characterized in that Determining a target steering wheel angle according to the feedforward steering wheel angle and the feedback steering wheel angle includes: Determining the actual feedforward weight corresponding to the actual curvature mean value according to the corresponding relationship between the curvature mean value and the feedforward weight; Determining the actual feedback weight corresponding to the actual curvature mean value according to the corresponding relationship between the curvature mean value and the feedback weight; A weighted sum is performed on the feedforward steering wheel angle and the corresponding feedforward weight, the feedback steering wheel angle and the corresponding feedback weight to determine the target steering wheel angle.

10. The method according to claim 9, characterized in that There is a positive correlation between the feedforward weight and the mean curvature; there is a negative correlation between the feedback weight and the mean curvature.

11. An electric power steering system, characterized in that: comprising a memory and a processor, wherein: The memory is used to store computer programs; The processor is configured to execute the computer program to implement the method for determining the steering wheel angle according to any one of claims 1 to 10.

12. A vehicle, characterized in that: The vehicle includes the electric power steering system according to claim 11.

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