Parking path processing method and device, electronic equipment and storage medium

Abstract

The invention relates to a parking path processing method and device, electronic equipment and a storage medium, and the method comprises the steps: determining a driving action sequence based on the driving action of a vehicle in an initial parking path, and carrying out the processing of a parking path under the condition that the current parking path is determined to be a one-step parking path based on the driving action sequence; an arc curve needing to be processed is determined on the basis of a curvature sudden change point, the arc curve is processed into a clothoid-arc-clothoid form with continuous curvature, and a final parking path is determined by combining a straight line part in an initial parking path, so that the control precision can be improved, in-situ steering of tires can be effectively avoided, and the parking efficiency is improved. And abrasion of tires in the parking process is reduced.

Description

Technical Field

[0001] This application relates to the technical field of automatic parking, and particularly to a parking path processing method, apparatus, electronic device, and storage medium. Background Art

[0002] With the continuous development of intelligent vehicle technology, automatic parking has become an indispensable part of intelligent vehicle autonomous driving. Among them, parking path planning plays the most important role. The existing parking path planning methods generally include geometric methods and search methods.

[0003] However, whether it is a geometric method or a search method, a combination splicing method of straight line - arc is used to obtain the parking path. This parking path often has a sudden change in curvature at the splicing of arc - straight line or arc - arc, resulting in poor control effect and the situation of the tire turning in place. Summary of the Invention

[0004] This application provides a parking path processing method, apparatus, electronic device, and storage medium, which can improve the control accuracy, effectively avoid the tire turning in place, and reduce the wear of the tire during parking.

[0005] In a first aspect, this application provides a parking path processing method, including:

[0006] Obtain the initial parking path of the vehicle, and determine the driving action sequence of the initial parking path, where the driving action sequence includes the driving actions corresponding to each path node in the initial parking path;

[0007] In the case where the initial parking path is determined to be a one - step parking path based on the driving action sequence, determine the arc curve in the initial parking path according to the curvature of each path node in the initial parking path;

[0008] Process the arc curve into a combination of a first clothoid - target arc - second clothoid, where the first endpoint of the first clothoid is the first endpoint of the arc curve, and the instantaneous radius of the first clothoid at the second endpoint meets the equal - condition with the radius of the target arc; the first clothoid and the second clothoid are symmetric about the connection line between the mid - point of the target arc and the center of the circle where the target arc is located;

[0009] Determine the final parking path according to the combination of the first clothoid - target arc - second clothoid and the straight - line part in the initial parking path.

[0010] In a second aspect, an embodiment of this application provides a parking path processing apparatus, including:

[0011] A driving action determination module, configured to obtain an initial parking path of a vehicle and determine a driving action sequence of the initial parking path, where the driving action sequence includes driving actions corresponding to each path node in the initial parking path;

[0012] An arc curve determination module, configured to determine an arc curve in the initial parking path according to the curvature of each path node in the initial parking path when it is determined that the initial parking path is a one-step parking path based on the driving action sequence;

[0013] An arc curve processing module, configured to process the arc curve into a combination of a first clothoid - target arc - second clothoid, where a first end point of the first clothoid is a first end point of the arc curve, and an instantaneous radius of the first clothoid at a second end point is equal to a radius of the target arc; the first clothoid and the second clothoid are symmetric about a connection line between a midpoint of the target arc and a center of a circle where the target arc is located;

[0014] A final parking path determination module, configured to determine a final parking path according to the combination of the first clothoid - target arc - second clothoid and a straight - line part in the initial parking path.

[0015] In a third aspect, an embodiment of the present application provides an electronic device, including:

[0016] A memory, configured to store a computer program;

[0017] A processor, configured to execute the computer program stored in the memory, and when the computer program is executed, implement the method provided by the embodiment of the present application.

[0018] In a fourth aspect, an embodiment of the present application provides a computer - readable storage medium, on which a computer program is stored, and characterized in that when the computer program is executed by a processor, the method provided by the embodiment of the present application is implemented.

[0019] The above technical solutions provided by the embodiments of the present application have the following advantages compared with the prior art: For the method provided by the embodiments of the present application, by determining a driving action sequence based on the driving actions of the vehicle in the initial parking path, when it is determined that the current initial parking path is a one-step parking path based on the driving action sequence, an arc curve to be processed is determined based on the curvature mutation point, the above arc curve is processed into a form of a clothoid-arc-clothoid with continuous curvature, and the final parking path is determined in combination with the straight line part in the initial parking path. Thereby, the control accuracy can be improved, the in-situ steering of the tire can be effectively avoided, the wear of the tire during the parking process can be reduced, and this is a post-processing operation step for the initial parking path, which does not affect the front-end planning of the initial parking path, can be decoupled from the front-end planning algorithm of the initial parking path, and is compatible with the front-end planning algorithms of any combination of arcs and straight lines, with strong compatibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present application and, together with the specification, are used to explain the principles of the present application.

[0021] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the accompanying drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] One or more embodiments are exemplarily illustrated by the pictures in the corresponding accompanying drawings. These exemplary illustrations do not limit the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements, unless otherwise stated, and the drawings in the drawings do not constitute a proportional limitation.

[0023] Figure 1 is a schematic diagram of a parking scenario;

[0024] Figure 2 is Figure 1 a schematic diagram of the path curvature change curve of the parking scenario shown;

[0025] Figure 3 is a schematic diagram of another parking scenario;

[0026] Figure 4 is Figure 3 a schematic diagram of the path curvature change curve of another parking scenario shown;

[0027] Figure 5 is a schematic diagram of yet another parking scenario;

[0028] Figure 6 isFigure 5 Schematic diagram of the path curvature change curve of another parking scenario shown;

[0029] Figure 7 It is a schematic diagram of a clothoid;

[0030] Figure 8 It is a flowchart of a parking path processing method provided by an embodiment of the present application;

[0031] Figure 9 It is Figure 1 Schematic diagram of the final parking path obtained after processing the initial parking path shown in;

[0032] Figure 10 It is Figure 9 Schematic diagram of the path curvature change of the final parking path shown;

[0033] Figure 11 It is Figure 3 Schematic diagram of the final parking path obtained after processing the initial parking path shown in;

[0034] Figure 12 It is Figure 11 Schematic diagram of the path curvature change of the final parking path shown;

[0035] Figure 13 It is Figure 5 Schematic diagram of the final parking path obtained after processing the initial parking path shown in;

[0036] Figure 14 It is Figure 13 Schematic diagram of the path curvature change of the final parking path shown;

[0037] Figure 15 It is a flowchart of a method for determining a driving action sequence of an initial parking path provided by an embodiment of the present application;

[0038] Figure 16 It is a flowchart of a method for determining an arc curve in an initial parking path according to the curvature of each path node in the initial parking path provided by an embodiment of the present application;

[0039] Figure 17 It is a flowchart of a method for processing each arc curve into a combination of a first clothoid - target arc - second clothoid provided by an embodiment of the present application;

[0040] Figure 18 It is a schematic diagram of the processing process of the arc curve in the initial parking path;

[0041] Figure 19It is a flowchart of a method provided by an embodiment of the present application for performing a symmetry operation on a target curve based on the connection line between the midpoint of a target arc and a target intersection point to obtain a combination of a first clothoid - target arc - second clothoid;

[0042] Figure 20 It is a flowchart for processing an arc curve in an initial parking path;

[0043] Figure 21 It is a structural block diagram of a parking path processing device provided by an embodiment of the present application;

[0044] Figure 22 It is a structural block diagram of an electronic device provided by an embodiment of the present application. Detailed implementation manners

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some but not all of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0046] The following disclosure provides many different embodiments or examples for implementing different structures of the present application. To simplify the disclosure of the present application, components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present application. In addition, the present application may repeat reference numerals and / or letters in different examples. This repetition is for the purpose of simplification and clarity and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0047] See Figure 1 , Figure 1 It is a schematic diagram of a parking scenario. As Figure 1 shown, the vehicle starts from point A and reverses along an arc curve AB with a fixed turning radius to point B to the right, maintains the reverse gear at point B, and then travels along the path straight line BC to point C to complete parking.

[0048] The above - mentioned parking path consists of an arc curve AB and a straight line BC, and the connection point is point B. The curve of the path curvature k with respect to the path length s is as Figure 2 shown. Among them, in the above - mentioned parking path, at the connection between the arc curve and the straight line, that is, at point B, the curvature changes suddenly, which is likely to cause poor control effect and there is a situation where the tire turns in place.

[0049] See Figure 3 , Figure 3 It is a schematic diagram of another parking scenario. AsFigure 3 As shown, the vehicle starts from point A and moves forward along the arc curve AB with a fixed turning radius to the left until it reaches point B. At point B, it maintains the forward gear and then travels along the straight path BC to point C to complete parking.

[0050] The above parking path consists of the arc curve AB and the straight line BC, and the connection point is point B. The curve of the path curvature k with respect to the path length s is as Figure 4 shown. Among them, in the above parking path, at the connection between the arc curve and the straight line, that is, at point B, the curvature undergoes a sudden change, which is likely to result in poor control effect and the situation of the tire turning in place.

[0051] See Figure 5 , Figure 5 which is a schematic diagram of another parking scenario. As Figure 5 shown, the vehicle starts from point A and reverses along the arc curve AB with a fixed turning radius to the right until it reaches point B. At point B, it maintains the reverse gear and then reverses along the arc curve BC with a fixed turning radius to the left until it reaches point C to complete parking.

[0052] The above parking path consists of the arc curve AB and the arc curve BC, and the connection point is point B. The curve of the path curvature k with respect to the path length s is as Figure 6 shown. Among them, in the above parking path, at the connection between the arc curve and the straight line, that is, at point B, the curvature undergoes a sudden change, which is likely to result in poor control effect and the situation of the tire turning in place.

[0053] The above scenarios are only examples, and other scenarios are similar and will not be elaborated here.

[0054] In order to solve the technical problems of poor control effect caused by the sudden change of curvature in the existing parking path and the situation of the tire turning in place, the present application provides a parking path processing method, device, electronic device and storage medium. By using a clothoid to process the arc curve in the parking path, the parking path can be transformed into a path with continuous curvature, improving the control accuracy, effectively avoiding the in-situ turning of the tire, and reducing the wear of the tire during parking. Among them, the clothoid can refer to the solid line part in Figure 7 , with O0 as the starting point and the curvature being 0, extending with a variable curvature to the point (x t , y t ) where the minimum turning radius R of the vehicle is reached min , and the instantaneous center of curvature is o t (x ot , y ot ). At this time, the path length traveled is L min . Among them, the formula of the clothoid curve is:

[0055] A 2 = RL

[0056] Among them, L is the arc length, R is the turning radius at the position where the arc length is L, and A characterizes the curvature characteristics of the spiral curve.

[0057] Figure 8 It is a flowchart of a parking path processing method provided by an embodiment of the present application. As Figure 8 shown, the method includes the following steps:

[0058] Step 801: Obtain the initial parking path of the vehicle and determine the driving action sequence of the initial parking path.

[0059] In the technical solution of the embodiment of the present application, the initial parking path can be a parking path planned by a geometric algorithm in the early stage. The initial parking path usually includes an arc curve part and / or a straight line part. For example, as Figure 1 and Figure 3 shown, the initial parking path includes the arc curve AB and the straight line BC. As Figure 3 shown, the initial parking path includes the arc curve AB and the arc curve BC.

[0060] The driving action sequence of the initial parking path includes the driving actions corresponding to each path node in the initial parking path. Among them, the driving action corresponding to a path node refers to the driving-related actions at this path node during the parking process, including but not limited to gear shifting actions, direction adjustment actions, etc. For example, in Figure 1 the shown scenario, the driving action corresponding to the path node A is: reverse gear and turn right, and the driving action corresponding to the path node B is: reverse gear and straighten the direction. In Figure 3 the shown scenario, the driving action corresponding to the path node A is: forward gear and turn left, and the driving action corresponding to the path node B is: forward gear and straighten the direction. In Figure 5 the shown scenario, the driving action corresponding to the path node A is: reverse gear and turn right, and the driving action corresponding to the path node B is: reverse gear and turn left.

[0061] Step 802: When it is determined that the initial parking path is a one-step parking path based on the driving action sequence, determine the arc curve in the initial parking path according to the curvature of each path node in the initial parking path.

[0062] In the technical solution of the embodiment of the present application, a one-step parking path refers to a driving path that does not require gear shifting during the parking process. Simply put, if only the reverse gear or only the forward gear is used throughout the parking process, it is regarded as a "one-step parking path". For example, Figure 1 , Figure 3 and Figure 5 the parking paths in the shown scenarios are all one-step parking paths, where Figure 1 and Figure 5The reverse gear is used throughout the parking path in the shown scenario. Figure 3 The forward gear is used throughout the parking path in the shown scenario.

[0063] For the case where the initial parking path is a one-step parking path, the initial parking path is regarded as a whole, and according to the curvature of each path node in the initial parking path, the circular arc curve in the initial parking path is determined.

[0064] For example, as Figure 1 or Figure 3 shown, the circular arc curve in the initial parking path A - B - C is the circular arc curve AB. As Figure 3 shown, the circular arc curves in the initial parking path A - B - C include the circular arc curve AB and the circular arc curve BC.

[0065] It can be seen from this that for the case where the initial parking path is a one-step parking path, regarding the initial parking path as a whole to determine the circular arc curve in the initial parking path does not mean that there is only one circular arc curve in the initial parking path. In fact, there are also cases where there are two or more circular arc curves.

[0066] Step 803: Process the circular arc curve into a combination of a first clothoid - target circular arc - second clothoid, where the first endpoint of the first clothoid is the first endpoint of the circular arc curve, and the instantaneous radius of the first clothoid at the second endpoint meets the equal condition with the radius of the target circular arc; the first clothoid and the second clothoid are symmetric about the connection line between the midpoint of the target circular arc and the center of the circle where the target circular arc is located.

[0067] The above first endpoint can be the starting point, and the corresponding second endpoint is the ending point, or the above first endpoint can be the ending point, and the corresponding second endpoint is the starting point. For the convenience of calculation, it can be considered that the first endpoint is the starting point and the second endpoint is the ending point.

[0068] Specifically, for each circular arc curve, the first endpoint of the circular arc curve can be used as the first endpoint of the first clothoid curve. By means of a calculation method, the second endpoint of the first clothoid curve is continuously explored until the second endpoint of the first clothoid curve is determined. Specifically, the second endpoint of the first clothoid curve can be continuously explored by comparing the instantaneous radius of the first clothoid curve at the second endpoint with the radius of the target circular arc until the instantaneous radius of the first clothoid curve at the second endpoint meets the equal condition with the radius of the target circular arc. The second endpoint of the first clothoid curve in this case is used as the second endpoint of the first clothoid curve that really needs to be found. After determining the second endpoint of the first clothoid curve, the first clothoid curve is determined. By using a calculation method, the midpoint of the target circular arc can be calculated. In the target circular arc, the circular arc from the second endpoint of the first clothoid curve to this midpoint can be used as the first circular arc. The combined curve formed by the first clothoid curve and the first circular arc is symmetrically operated based on the connection line between the midpoint of the target circular arc and the center of the circle where the target circular arc is located, obtaining a second circular arc symmetric to the first circular arc and a second clothoid curve symmetric to the first clothoid curve. Thus, the first clothoid curve, the first circular arc, the second circular arc, and the second clothoid curve are combined to obtain a combination of the first clothoid curve - target circular arc - second clothoid curve. Among them, the first circular arc and the second circular arc are combined to form the target circular arc.

[0069] Step 804: Determine the final parking path according to the combination of the first clothoid curve - target circular arc - second clothoid curve and the straight-line part in the initial parking path.

[0070] Specifically, each circular arc curve corresponds to a combination of the first clothoid curve - target circular arc - second clothoid curve. In the initial parking path, each circular arc curve is replaced with the corresponding combination of the first clothoid curve - target circular arc - second clothoid curve to obtain the final parking path. Exemplarily, as Figure 9 shown, Figure 9 corresponding to Figure 1 the final one-step parking path obtained after processing the one-step parking path in Figure 1 The final one-step parking path can be the solid line part formed by ABC, where the dashed line part is Figure 1 the circular arc curve part in the initial one-step parking path in Figure 9 After processing the circular arc curve part in the initial one-step parking path in Figure 10 the curvatures of points A, B, and C in the final one-step parking path in are continuously smooth. As shown in the schematic diagram of the curvature change of the one-step parking path after processing in It gradually increases to 0 at point B, and the curvature from point B to point C remains unchanged, achieving curvature continuity at the geometric connection point. Figure 10 The solid line part in Figure 9 corresponds to the curvature change of the one-step parking path of the solid line part after processing in Figure 10 The dotted line part in is the curvature of the circular arc section from point A to point B of the initial one-step parking path before processing. It can be seen that the curvature of the circular arc section from point A to point B of the one-step parking path before processing remains unchanged, and the curvature from point B to point C undergoes a sudden change. However, for the one-step parking path after processing, the curvature of the circular arc section from point A to point B remains unchanged, and the curvature from point B to point C gradually increases to 0, with continuous curvature and no sudden change. There is no problem of sudden change in curvature.

[0071] Similarly, Figure 11 is Figure 3 a schematic diagram of the one-step parking path with continuous curvature obtained after processing the initial one-step parking path in Figure 11 The dotted line part in Figure 3 corresponds to the circular arc section AB in the initial one-step parking path in Figure 11 The solid line part in Figure 3 is the final parking path with continuous curvature obtained after processing the initial one-step parking path in Figure 12 is Figure 11 a schematic diagram of the curvature change corresponding to the final parking path of the solid line part in

[0072] Figure 13 is Figure 5 a schematic diagram of the final parking path obtained after processing the initial one-step parking path in Figure 13 The dotted line part in Figure 5 corresponds to the circular arc section AB and the circular arc section BC in the initial one-step parking path in Figure 13 The solid line part in Figure 5 is the final parking path with continuous curvature obtained after processing the initial one-step parking path in Figure 14 is Figure 13 a schematic diagram of the curvature change corresponding to the final parking path of the solid line part in

[0073] The technical solution provided by the embodiment of the present application obtains the initial parking path of the vehicle. When it is determined that the initial parking path is a one-step parking path, the circular arc curves in the initial parking path are determined according to the curvature of each path node in the initial parking path. Each circular arc curve in the initial parking path is processed into a combination of a first clothoid curve - target circular arc - second clothoid curve, and each circular arc curve can be processed into a curve with continuous curvature. Specifically, by using the first endpoint of the first clothoid curve as the first endpoint of the circular arc curve, and making the instantaneous radius of the first clothoid curve at the second endpoint equal to the radius of the target circular arc, the first clothoid curve and the target circular arc can be made to have continuous curvature at the second endpoint of the first clothoid curve. Through the second clothoid curve symmetric to the first clothoid curve, the connection point between the target circular arc and the second clothoid curve can be made to have continuous curvature, ensuring that the combination of the first clothoid curve - target circular arc - second clothoid curve formed by each circular arc has continuous curvature. Thus, the parking path can be transformed into a path with continuous curvature, improving the control accuracy, effectively avoiding the in-situ steering of the tires, and reducing the wear of the tires during parking.

[0074] In the prior art, in the post-processing solution for the parking path, most use numerical optimization methods to obtain a parking path with continuous curvature. However, because this method involves solving non-linear optimization problems, the solution efficiency is low, it is difficult to implement in engineering, and usually, a non-linear problem needs to be modeled during the initial parking path planning at the front end. Therefore, the path planning of the initial parking path at the front end and the back-end processing cannot be well decoupled. The technical solution provided by the present application is a post-processing of the initial parking path, which does not affect the planning of the initial parking path at the front end, can be decoupled from the planning algorithm of the initial parking path at the front end, is compatible with any front-end planning algorithm composed of circular arcs and straight lines, has strong compatibility, and does not change the positions of the endpoints of any circular arc curves in the initial parking path, can maintain the shift points of the initial parking path planned at the front end, and is consistent with the decision-making at the front end, with high reliability.

[0075] Figure 15 It is a flowchart of a method for determining the driving action sequence of the initial parking path provided by the embodiment of the present application. Figure 15 The process shown in Figure 8 On the basis of the process shown, this process includes the following steps:

[0076] Step 1501: Obtain the path parameters of each path node in the initial parking path, where the path parameters include coordinate information and heading angle.

[0077] In one embodiment, the coordinate information of a path node refers to the abscissa and ordinate of the path node in an absolute coordinate system, which means that each path node in the initial parking path has a clear position description information relative to a certain fixed reference point. In addition to the coordinate information, the heading angle is also one of the key information, and the heading angle describes the driving direction of the vehicle at each path node.

[0078] When planning the initial parking path through a path planning algorithm, such as a geometric algorithm, the coordinate information and the heading angle of each path node will be determined to ensure that the vehicle can park smoothly along this path.

[0079] Step 1502: For each path node in the initial parking path, based on the path parameters of the path node and the path parameters of its next path node, determine the moving direction angle of the next path node relative to the path node.

[0080] Step 1503: For each path node in the initial parking path, determine the driving gear corresponding to the path node based on the moving direction angle corresponding to the path node.

[0081] As an alternative implementation, for each path node in the initial parking path, determining the driving gear corresponding to the path node based on the moving direction angle corresponding to the path node includes:

[0082] Determine the driving gear corresponding to the path node based on the following formula:

[0083]

[0084] where S i is the driving gear corresponding to the i-th path node, 1 represents reverse gear, and 0 represents forward gear;

[0085] θ r is the moving direction angle, x i and y i are the abscissa and ordinate of the i-th path node respectively, and x i+1 and y i+1 are the abscissa and ordinate of the (i + 1)-th path node respectively.

[0086] Step 1504: According to the sequence of multiple path nodes, sort the driving gears corresponding to the multiple path nodes to obtain the driving action sequence of the initial parking path.

[0087] Step 1505: Determine that the initial parking path is a one-step parking path based on the driving action sequence.

[0088] As an alternative implementation, the driving gears corresponding to multiple path nodes are sorted in the order of the path nodes to obtain a driving action sequence. When the driving gears of all path nodes in the entire driving action sequence are the same, the initial parking path is determined to be a one-step parking path. Herein, the driving gears include forward gear and reverse gear.

[0089] As another alternative implementation, it is also possible to determine whether the driving gears of every two adjacent path nodes are the same by means of formula calculation. When the driving gears of every two adjacent path nodes are the same, it indicates that the driving gears of all path nodes throughout the parking path are the same, that is, when the vehicle parks using this parking path, no gear shifting is required throughout the process.

[0090] Specifically, when the following formula holds, the initial parking path is determined to be a one-step parking path:

[0091]

[0092] where N is the number of path nodes, and S i+1 is the driving gear corresponding to the (i + 1)-th path node.

[0093] The calculation logic of the above formula (2) is as follows: The consistency of the gear actions of every two adjacent path nodes is determined by the calculation method of |S i - S i+1 |. Among them, |S i - S i+1 | = 0 means that the gear actions of two adjacent path nodes are the same. Then, the consistency of the gear actions of all path nodes throughout the process is determined by cumulatively summing the calculation results of the consistency of the gear actions of every two adjacent path nodes. Among them, if it means that the gear actions of all path nodes throughout the parking path are the same, that is, the gear actions throughout the parking path are the same and there is no gear shifting behavior.

[0094] For example, referring to the initial parking path in the scenario shown in Figure 1 , this parking path includes path node A, path node B, and path node C. Among them, the driving gear of path node A is reverse gear, that is, S A = 1; the driving gear of path node B is reverse gear, that is, S B = 1; the driving gear of path node C is reverse gear, that is, S C = 1; the driving gears of these path nodes can all be determined based on the above formula (1) according to their respective moving direction angles, which will not be elaborated here. Therefore, the driving action sequence of the ABC section of the parking path composed of the above path nodes A, B, and C is {S A= 1, S B = 1, S C = 1}, calculate the consistency of the gear shifting actions between any two adjacent nodes based on the above formula (2): |S A - S B | = 0, |S B - S C | = 0, |S A - S B | +

[0095] |S B - S C | = 0, and obtain the result by calculating the cumulative sum of the calculation results of the gear shifting action consistency between adjacent two path nodes. The result is 0, which means that the gear shifting actions of all path nodes throughout the process are consistent and there is no gear shifting behavior. It can be seen that Figure 2 the driving gear throughout the corresponding initial parking path remains consistent and there is no gear shifting behavior. Therefore, it can be determined that this initial parking path is the one-step parking path.

[0096] Refer to Figure 3 the initial parking path in the shown scenario. This parking path includes path node A, path node B, and path node C. Among them, the driving gear of path node A is forward gear 0, that is, S A = 0; the driving gear of path node B is forward gear 0, that is, S B = 0; the driving gear of path node C is forward gear 0, that is, S C = 0; the driving gears of these path nodes can all be determined based on their respective moving direction angles according to the above formula (1), which will not be elaborated here. Therefore, the driving action sequence of the ABC section of the parking path composed of the above path nodes A, path node B, and path node C is {S A = 0, S B = 0, s C = 0}, calculate the consistency of the gear shifting actions between any two adjacent nodes based on the above formula (2): |S A - S B | = 0, |S B - S C | = 0, |S A - S B | +

[0097] |S B - S C | = 0, and obtain the result by calculating the cumulative sum of the calculation results of the gear shifting action consistency between adjacent two path nodes. The result is 0, which means that the gear shifting actions of all path nodes throughout the process are consistent and there is no gear shifting behavior. It can be seen that Figure 4In the corresponding initial parking path, the driving gear remains the same throughout the whole process and there is no gear shifting behavior. Therefore, it can be determined that this initial parking path is a one-step parking path.

[0098] See Figure 5 the initial parking path in the shown scenario. This parking path includes path node A, path node B, and path node C. Among them, the driving gear of path node A is reverse gear, i.e., S A = 1; the driving gear of path node B is reverse gear, i.e., S B = 1; the driving gear of path node C is reverse gear 1, i.e., S C = 1; the driving gears of these path nodes can all be determined based on their respective moving direction angles according to the above formula (1), which will not be elaborated here. Therefore, the driving action sequence of the ABC section of the parking path composed of the above path node A, path node B, and path node C is {S A = 1, S B = 1, S C = 1}. Based on the above formula (2), calculate the consistency of the gear actions between any two adjacent nodes: |S A -S B | = 0, |S B -S C | = 0, |S A -S B | + |S B -S C | = 0. The calculation method of accumulating and summing the calculation results of the gear action consistency between adjacent two path nodes gets the result 0, that is, the gear actions of all path nodes throughout the whole process are consistent and there is no gear shifting behavior. It can be seen that Figure 6 in the corresponding initial parking path, the driving gear remains the same throughout the whole process and there is no gear shifting behavior. Therefore, it can be determined that this initial parking path is a one-step parking path.

[0099] By determining the driving gear of the vehicle under this path node based on the moving direction angle of the vehicle in the initial parking path, and determining the driving action sequence of the initial parking path according to the driving gear of the vehicle under each path node, and further determining whether the initial parking path is a one-step parking path according to the driving action sequence, the calculation method is simple, which is convenient for the vehicle to quickly identify the current parking path. Further, post-processing the current parking path to obtain a final parking path with continuous curvature can improve the control of the vehicle steering wheel during parking, avoid tire wear, and at the same time avoid the vehicle deviating from the parking path.

[0100] Figure 16 is a flowchart of a method for determining the arc curve in the initial parking path according to the curvature of each path node in the initial parking path provided by an embodiment of the present application. Figure 16 The process shown in Figure 8Based on the process shown, the process includes the following steps:

[0101] Step 1601: For non-first path nodes in the initial parking path, determine whether the curvature of a path node and the curvature of its previous path node satisfy a preset equality condition.

[0102] Step 1602: In the case where the curvature of a path node and the curvature of its previous path node do not satisfy the equality condition, determine the path node as a curvature mutation point.

[0103] In the technical solution of the embodiment of the present application, the preset equality condition does not mean that the curvatures are exactly the same, but allows a certain difference in the curvatures of two adjacent path nodes, as long as this difference is within an acceptable range. That is to say, the preset equality condition is actually a tolerance range for determining whether the curvatures of two adjacent nodes are "close enough" to maintain the smoothness of the path.

[0104] Based on this, as an optional implementation manner, it can be determined whether the curvatures of adjacent path nodes satisfy the preset equality condition by judging whether the absolute value of the difference in curvatures of adjacent path nodes exceeds a set threshold. Among them, if the absolute value of the difference in curvatures of adjacent path nodes exceeds the set threshold, it means that the preset equality condition is not satisfied; if the absolute value of the difference in curvatures of adjacent path nodes does not exceed the set threshold, it means that the preset equality condition is satisfied.

[0105] Furthermore, based on the above description, in the case where the curvature of a path node and the curvature of its previous path node do not satisfy the equality condition, determine the path node as a curvature mutation point.

[0106] For example, Figure 1 in the shown scenario, referring to Figure 2 the curvature change diagram of the initial parking path shown, it can be known that the curvature of path node B is 0, while the curvature of path node A is The absolute value of the difference in curvatures between path node A and path node B is Assume the preset threshold is Then it shows that the absolute value of the difference in curvatures between path node A and path node B exceeds the set threshold, which means that the difference in curvatures between path node A and path node B is very large and not "close enough", so path node B is determined as a curvature mutation point.

[0107] Figure 3 in the shown scenario, referring to Figure 4 the curvature change diagram of the initial parking path shown, it can be known that the curvature of path node B is 0, while the curvature of path node A is The absolute value of the difference in curvatures between path node A and path node B is Assume that the preset threshold is It indicates that the absolute value of the difference in curvature between path node A and path node B exceeds the set threshold, which means that the curvature difference between path node A and path node B is very large and not "sufficiently close", so path node B is determined as the curvature mutation point.

[0108] Figure 5 In the shown scenario, referring to Figure 6 the curvature change diagram of the initial parking path shown, it can be known that the curvature of path node B is while the curvature of path node A is The absolute value of the difference in curvature between path node A and path node B is Assume that the preset threshold is It indicates that the absolute value of the difference in curvature between path node A and path node B exceeds the set threshold, which means that the curvature difference between path node A and path node B is very large and not "sufficiently close", so path node B is determined as the curvature mutation point.

[0109] Step 1603: Determine the non-straight path segment between the curvature mutation point and its adjacent path nodes as the arc curve in the initial parking path.

[0110] The initial parking path includes but is not limited to curves, straight lines, etc. When the curvature mutation point in the initial parking path is determined, the path segment composed of the path nodes adjacent to the curvature mutation point is not necessarily a curve and may also be a straight line. Therefore, the non-straight path segment between the curvature mutation point and its adjacent path nodes is determined as the arc curve in the initial parking path.

[0111] Referring to Figure 1 the shown scenario, based on the above steps, it is determined that Figure 1 path node B shown in is the curvature mutation point. There are two path nodes adjacent to path node B: path node A and path node C. However, the path segment BC composed of path node B and path node C is a straight path segment. Therefore, the path segment AB composed of path node B and path node A is determined as the arc curve in the initial parking path.

[0112] Referring to Figure 3 the shown scenario, based on the above steps, it is determined that Figure 3 path node B shown in is the curvature mutation point. There are two path nodes adjacent to path node B: path node A and path node C. However, the path segment BC composed of path node B and path node C is a straight path segment. Therefore, the path segment AB composed of path node B and path node A is determined as the arc curve in the initial parking path.

[0113] Referring to Figure 5 the shown scenario, based on the above steps, it is determined thatFigure 5 The path node B shown in Figure 5 is a curvature mutation point. There are two path nodes adjacent to the path node B: the path node A and the path node C. And the path segment BC formed by the path node B and the path node C is a non-straight path segment, and the path segment AB formed by the path node B and the path node A is also a non-straight path segment. Therefore, both the path segment AB and the path segment BC are determined as the circular arc curves in the initial parking path.

[0114] Through Figure 16 the process shown in Figure 16 , the curvature mutation point is determined according to the curvature of the path node, and the circular arc curve that needs to be processed is found based on the curvature mutation point. This method can help the vehicle quickly find the circular arc curve that needs to be processed and improve the processing efficiency of the vehicle for the circular arc curve.

[0115] Figure 17 FIG. 10 is a flowchart of a method provided by an embodiment of the present application for processing each circular arc curve into a combination of a first clothoid curve - target circular arc - second clothoid curve. Figure 17 The process shown in Figure 17 is based on the process shown in Figure 8 . This process includes the following steps: Figure 8 On the basis of the process shown in Figure 8 , this process includes the following steps:

[0116] Step 1701: For each circular arc curve, determine the center of the circle where the circular arc curve is located and determine the target straight line passing through the center of the circle where the circular arc curve is located and the target midpoint, where the target midpoint is the midpoint of the line segment formed by the two endpoints of the circular arc curve.

[0117] As an alternative implementation, determining the center of the circle where the circular arc curve is located includes: determining the center of the circle where the circular arc curve is located based on the following formula:

[0118]

[0119] where x c and y c are respectively the abscissa and ordinate of the center of the circle where the circular arc curve is located; x1, y1, and θ1 are respectively the abscissa, ordinate, and heading angle of the first endpoint of the circular arc curve; x2, y2, and θ2 are respectively the ordinates of the second endpoint of the circular arc curve. Wherein, for illustration with reference to Figure 18 , the center of the circle where the circular arc curve is located is determined according to the two endpoints of the circular arc curve. As shown in Figure 18 , the two endpoints on the circular arc curve are respectively p1(x1, y1, θ1) and p2(x2, y2, θ2); Figure 18 For illustration with reference to Figure 18 , the center of the circle where the circular arc curve is located is determined according to the two endpoints of the circular arc curve. As shown in Figure 18 , the two endpoints on the circular arc curve are respectively p1(x1, y1, θ1) and p2(x2, y2, θ2); Figure 18 For the circular arc curve to be processed, the center c(x For the circular arc curve to be processed, the center c(x of the circle where the circular arc curve is located is calculated according to the above formula (1). c , y c) It should be noted that when calculating the coordinates of the center of the circular arc curve, for the convenience of calculation, the coordinate system can be first transformed from the absolute coordinate system to the coordinate system with the first endpoint p1(x1, y1, θ1) of the circular arc curve as the vertex, and then the calculation can be carried out. As Figure 18 shown, the target midpoint is the midpoint of the line segment formed by the two endpoints of the circular arc curve , that is, the midpoint of the line segment p1p2, which is point m. The target line passing through the center c point of the circle where the circular arc curve is located and the target midpoint m is the line cm.

[0120] Step 1702: Take the first endpoint of the circular arc curve as the first endpoint of the first clothoid curve.

[0121] Refer to Figure 18 for illustration. As Figure 18 shown, the first endpoint (point p1) of the circular arc curve is taken as the first endpoint of the first clothoid curve.

[0122] Step 1703: Preset the arc length of the first clothoid curve as the current preset arc length, and determine the initial second endpoint of the first clothoid curve based on the current preset arc length.

[0123] As an optional implementation manner, determining the initial second endpoint of the first clothoid curve based on the current preset arc length includes: determining the initial second endpoint of the first clothoid curve based on the following formula:

[0124]

[0125] where x, y, and θ are the abscissa, ordinate, and heading angle of the initial second endpoint of the first clothoid curve in the coordinate system with the first endpoint of the circular arc curve as the vertex;

[0126] where A is the parameter of the first clothoid curve, where

[0127] where V max is the maximum vehicle speed during parking, D max is the maximum steering wheel angle, O max is the maximum angular velocity of the steering wheel, s ′ ∈[0, L min , is the current preset arc length, and R min is the minimum turning radius.

[0128] Refer to Figure 18 for illustration. As Figure 18 shown, the other endpoint of the first clothoid curve with the current preset arc length of s ′ is point c1, which is used as the initial second endpoint of the first clothoid curve, where, asFigure 18 As shown, the first clothoid is the solid line curve from point p1 to point c1. The coordinates of the initial second endpoint c1 of the first clothoid and the course angle θ can be calculated through the above formula (4). A characterizes the curvature characteristic of the first clothoid and can be calculated through the above formula (5).

[0129] Step 1704: Determine the intersection point of the normal line passing through the initial second endpoint and the target line as the target intersection point, and determine the length between the target intersection point and the initial second endpoint as the radius of the target arc.

[0130] Refer to Figure 18 for illustration. As Figure 18 shown, the intersection point of the normal line passing through the initial second endpoint (point c1) and the target line (line cm) is point o, that is, the target intersection point is point o. The length between the target intersection point and the initial second endpoint is the length from point o to point c1, that is, the length of line segment oc1. The length of oc1 is actually the radius R of the target arc (the arc from c1 to c2, and the coordinates of point c2 are unknown at this time). cc .

[0131] As an alternative implementation, determining the intersection point of the normal line passing through the initial second endpoint and the target line includes: determining the intersection point of the normal line of the initial second endpoint and the target line based on the following formula:

[0132]

[0133] where x o , y o are respectively the abscissa and ordinate of the target intersection point in the coordinate system with the first endpoint of the circular arc curve as the vertex;

[0134] where

[0135] where k s is the slope of the target line; x m , y m are respectively the abscissa and ordinate of the target midpoint in the coordinate system with the first endpoint of the circular arc curve as the vertex; x c , y c are respectively the abscissa and ordinate of the center of the circle where the circular arc curve is located in the coordinate system with the first endpoint of the circular arc curve as the vertex.

[0136] As an alternative implementation, determining the length between the target intersection point and the initial second endpoint includes: determining the length between the target intersection point and the initial second endpoint based on the following formula:

[0137]

[0138] wherein, R cc is the length between the target intersection point and the initial second endpoint, serving as the radius of the target arc; x o , y o are respectively the abscissa and ordinate of the target intersection point in the coordinate system with the first endpoint of the arc curve as the vertex, and x and y are respectively the abscissa and ordinate of the initial second endpoint in the coordinate system with the first endpoint of the arc curve as the vertex.

[0139] wherein, referring to Figure 18 , k s is the slope of the straight line cm, which can be calculated through the above formula (7), that is, calculated through the coordinates of point c and point m; the coordinates of the intersection point (point o) of the normal line passing through the initial second endpoint (point c1) and the target straight line (cm) can be calculated through the above formula (6), and the length R of oc1 cc can be calculated through the above formula (8), which is also the radius of the target arc c1c2. It should be noted that at this time, the first endpoint c1 of the target arc is determined, and the second endpoint c2 of the target arc is not determined yet. Here, c2 is introduced for the convenience of description and understanding, and the coordinates of c2 are not introduced in the calculation of the above formulas.

[0140] Step 1705: Determine whether the radius of the target arc is equal to the instantaneous radius of the first clothoid at the initial second endpoint.

[0141] In the technical solution of the embodiment of the present application, in step 1705, by determining whether the difference between the radius of the target arc and the instantaneous radius of the first clothoid at the initial second endpoint is less than a preset error value. If so, it is determined that the two meet the equal condition; if not, it is determined that the two do not meet the equal condition. This preset threshold can be obtained based on the test data during the actual operation of the vehicle.

[0142] In the technical solution of the embodiment of the present application, if it is determined that the radius of the target arc and the instantaneous radius of the first clothoid at the initial second endpoint do not meet the equal condition, execute 1706; if they meet the equal condition, execute 1707.

[0143] In an alternative embodiment, it is determined whether the radius of the target arc and the instantaneous radius meet the equal condition based on the following formula:

[0144]

[0145] wherein, R cc is the radius of the target arc, ε is the preset error value, and r c is the instantaneous radius.

[0146] Refer to Figure 18 for description. For example, Figure 18As shown, when the radius of the target circular arc c1c2 (the length of the line segment oc1, R cc ) is equal to the instantaneous radius r of the first clothoid p1c1 at point c1 c , it indicates that the curvature of the first clothoid p1c1 and the target circular arc c1c2 is continuous at point c1. Therefore, it is necessary to determine whether the radius of the target circular arc c1c2 is equal to the instantaneous radius r of the first clothoid p1c1 at point c1 c to understand whether the curvature of the first clothoid p1c1 and the target circular arc c1c2 is continuous at point c1.

[0147] Step 1706: Change the current preset arc length, use the changed arc length as the current preset arc length, and return to Step 1703.

[0148] Step 1707: Use the last initial second endpoint as the second endpoint of the first clothoid.

[0149] As an alternative implementation, the bisection method can be used to change the current preset arc length, return to Step 1703, and repeat Steps 1703 - 1705. Use the last initial second endpoint as the second endpoint of the first clothoid. The specific method of using the bisection method to change the current preset arc length is to divide the current preset arc length into two parts. According to the comparison result of the target length and the instantaneous radius, determine whether to select the length of the changed arc length in the first half or the second half of the current preset arc length. After determining the changed arc length, return to Step 1703 until the radius of the target circular arc is equal to the instantaneous radius. Refer to Figure 18 , as Figure 18 shown, when the length of the line segment oc1 is equal to the instantaneous radius r of the first clothoid p1c1 at point c1 c , use the obtained point c1 at this time as the second endpoint of the final first clothoid.

[0150] Step 1708: Determine the midpoint of the target circular arc; where, the center of the circle where the target circular arc is located is the target intersection point, and the first endpoint of the target circular arc is the second endpoint of the first clothoid.

[0151] As an alternative implementation, determining the midpoint of the target circular arc includes: determining the midpoint of the target circular arc based on the following formula:

[0152]

[0153] where α is the semi - central angle of the target circular arc; x h , y h and θ hThey are respectively the abscissa, ordinate and heading angle of the midpoint of the target circular arc in the coordinate system with the first endpoint of the circular arc curve as the vertex. is the vector from the target intersection point to the target midpoint, is the vector from the target intersection point to the second endpoint of the first clothoid curve.

[0154] Reference Figure 18 For illustration, by continuously determining the second endpoint of the first clothoid curve p1c1, the finally obtained c1 point is used as the second endpoint of the first clothoid curve. The first endpoint of the target circular arc c1c2 is the second endpoint of the first clothoid curve p1c1, that is, the c1 point. The center of the circle where the target circular arc c1c2 is located is the o point, and the radius of the circle is the line segment oc1. The h point is the midpoint of the target circular arc.

[0155] Calculate the midpoint of the target circular arc c1c2 through the above formula (10), is is α is the semi-central angle of the target circular arc c1c2.

[0156] Step 1709: Perform a symmetry operation on the target curve based on the line connecting the midpoint of the target circular arc to the target intersection point to obtain a combination of the first clothoid curve - target circular arc - second clothoid curve; wherein, the target curve is a curve obtained by combining the first clothoid curve and the first circular arc based on the first endpoint and the second endpoint of the first clothoid curve; the first circular arc is the circular arc between the second endpoint of the first clothoid curve and the midpoint of the target circular arc in the target circular arc.

[0157] Reference Figure 18 For illustration, as Figure 18 shown, the target curve is the curve p1c1h formed by the first clothoid curve p1c1 and the first circular arc c1h. By performing a symmetry operation on the curve p1c1h based on the line segment oh, a combination of the first clothoid curve - target circular arc - second clothoid curve can be obtained, thereby transforming the circular arc curve into the curve p1c1hc2p2.

[0158] Figure 19 is a flowchart of a method for performing a symmetry operation on a target curve based on the line connecting the midpoint of the target circular arc to the target intersection point to obtain a combination of the first clothoid curve - target circular arc - second clothoid curve provided by an embodiment of the present application. Figure 19 The process shown in Figure 17 is based on the process shown in

[0159] Step 1901: Determine the symmetric point of the second endpoint of the first clothoid curve symmetric about the target symmetry line; wherein, the target symmetry line is the line connecting the midpoint of the target circular arc to the target intersection point.

[0160] As an alternative implementation, determining the symmetric point of the second endpoint of the first clothoid curve that is symmetric about the target symmetry line includes:

[0161] Determining the symmetric point based on the following formula:

[0162]

[0163] where and are respectively the abscissa and ordinate of the symmetric point in the coordinate system with the first endpoint of the circular arc curve as the vertex. In the above formula (11), d x , d y and l are intermediate quantities in the calculation process. Referring to Figure 18 , the symmetric point of the second endpoint c1 of the first clothoid curve p1c1 that is symmetric about the target symmetry line oh is c2, and the coordinates of the symmetric point c2 can be calculated through the above formula (11). The reason for calculating the symmetric point c2 first in this application is to find the segmentation point of the target circular arc and the second clothoid curve, so as to make the symmetric operation more efficient.

[0164] Step 1902: Between the symmetric point and the second endpoint of the circular arc curve, determine the second clothoid curve of the first clothoid curve that is symmetric about the target symmetry line.

[0165] Step 1903: Between the midpoint of the target circular arc and the symmetric point, determine the second circular arc of the first circular arc that is symmetric about the target symmetry line.

[0166] Step 1904: The first clothoid curve, the first circular arc, the second circular arc, and the second clothoid curve form a combination of the first clothoid curve - target circular arc - second clothoid curve.

[0167] For a unified description of steps 1902 - 1904, in step 1902, discrete points are selected on the first clothoid curve, these discrete points are symmetric about the target symmetry line, the corresponding symmetric points are found, and the symmetric point of the second endpoint of the first clothoid curve, the symmetric points corresponding to these discrete points, and the second endpoint of the circular arc curve are connected in sequence to obtain the second clothoid curve. Referring to Figure 18 , discrete points are selected on the first clothoid curve p1c1, these discrete points are symmetric about the line segment oh, a series of corresponding symmetric points are obtained, and the point c2, a series of symmetric points corresponding to these discrete points, and the point p2 are connected in sequence to obtain the second clothoid curve c2p2.

[0168] In step 1903, discrete points are selected on the first circular arc. These discrete points are symmetrically based on the target symmetric point to find the corresponding symmetric points. The midpoint of the target circular arc, the symmetric points corresponding to these discrete points, and the symmetric point of the second endpoint of the first clothoid are connected in sequence to obtain the second circular arc. Refer to Figure 18 , discrete points are selected on the first circular arc c1h. These discrete points are symmetrically based on the line segment oh to obtain a series of corresponding symmetric points; the point h, a series of symmetric points corresponding to these discrete points, and the point c2 are connected in sequence to obtain the second circular arc hc2.

[0169] In step 1904, refer to Figure 18 , the first clothoid p1c1, the first circular arc c1h, the second circular arc hc2, and the second clothoid c2p2 are combined to obtain the curve p1c1hc2p2, that is, the combination of the first clothoid - target circular arc - second clothoid.

[0170] Among them, the process of processing the circular arc curve in the initial parking path provided in this embodiment can refer to Figure 20 , and the electronic device obtains the final parking path by executing the process shown in Figure 20 .

[0171] The technical solution provided in the embodiment of the present application processes each circular arc curve in the initial parking path through a geometric algorithm to obtain a curve with continuous curvature. Using the geometric algorithm, the calculation efficiency is high, the practicability is strong, and it is suitable for engineering implementation.

[0172] Figure 21 is a structural block diagram of a parking path processing device provided in the embodiment of the present application. As shown in Figure 21 , it includes:

[0173] A driving action determination module 2110, configured to obtain the initial parking path of the vehicle and determine the driving action sequence of the initial parking path. The driving action sequence includes the driving actions corresponding to each path node in the initial parking path;

[0174] A circular arc curve determination module 2120, configured to determine the circular arc curve in the initial parking path according to the curvature of each path node in the initial parking path when it is determined that the initial parking path is a one-step parking path based on the driving action sequence;

[0175] An arc curve processing module 2130 is configured to process the arc curve into a combination of a first clothoid curve - a target arc - a second clothoid curve, where a first endpoint of the first clothoid curve is the first endpoint of the arc curve, and an instantaneous radius of the first clothoid curve at a second endpoint is equal to the radius of the target arc; the first clothoid curve and the second clothoid curve are symmetric about a line connecting the midpoint of the target arc and the center of the circle where the target arc is located.

[0176] A final parking path determining module 2140 is configured to determine a final parking path according to the combination of the first clothoid curve - the target arc - the second clothoid curve and a straight-line part in the initial parking path.

[0177] In a possible implementation manner, the driving action determining module 2110 includes:

[0178] A path parameter determining unit is configured to obtain path parameters of each path node in the initial parking path, where the path parameters include coordinate information and a heading angle.

[0179] A path node processing unit is configured to perform the following processing on each path node in the initial parking path:

[0180] A moving direction angle determining unit is configured to determine a moving direction angle of the next path node relative to the path node based on the path parameters of the path node and the path parameters of its next path node.

[0181] A driving gear determining unit is configured to determine a driving gear corresponding to the path node based on the moving direction angle.

[0182] A driving action sequence determining unit is configured to sort the driving gears corresponding to multiple path nodes in the order of the multiple path nodes to obtain a driving action sequence of the initial parking path.

[0183] In a possible implementation manner, the driving gear determining unit includes:

[0184] Determine the driving gear corresponding to the path node based on the following formula:

[0185]

[0186] where S i is the driving gear corresponding to the i-th path node, 1 represents reverse gear, and 0 represents forward gear;

[0187] θ r is the moving direction angle, x i 、y iare the abscissa and ordinate of the i-th path node, x i+1 , y i+1 are the abscissa and ordinate of the (i + 1)-th path node respectively.

[0188] When the following formula holds, determine that the initial parking path is a one-step parking path:

[0189]

[0190] where N is the number of path nodes, and S i+1 is the driving gear corresponding to the (i + 1)-th path node.

[0191] In a possible implementation, the circular arc curve determination module 2120 includes:

[0192] For non-first path nodes in the initial parking path, determine whether the curvature of the path node satisfies a preset equal condition with the curvature of its previous path node;

[0193] When the curvature of the path node does not satisfy the equal condition with the curvature of its previous path node, determine the path node as a curvature mutation point;

[0194] Determine the non-straight path segment between the curvature mutation point and its adjacent path node as the circular arc curve in the initial parking path.

[0195] In a possible implementation, the circular arc curve processing module 2130 includes:

[0196] The first determination unit is used to, for each circular arc curve, determine the center of the circle where the circular arc curve is located and determine the target line passing through the center of the circle where the circular arc curve is located and the target midpoint, where the target midpoint is the midpoint of the line segment formed by the two endpoints of the circular arc curve;

[0197] The second determination unit is used to use the first endpoint of the circular arc curve as the first endpoint of the first clothoid curve, preset the arc length of the first clothoid curve as the current preset arc length, and determine the initial second endpoint of the first clothoid curve based on the current preset arc length;

[0198] The third determination unit is used to determine the intersection point of the normal line passing through the initial second endpoint and the target line as the target intersection point, and determine the length between the target intersection point and the initial second endpoint as the radius of the target circular arc;

[0199] The judgment unit is used to judge whether the radius of the target circular arc meets the equal condition with the instantaneous radius of the first clothoid curve at the initial second endpoint;

[0200] A return unit, for if not, changing the current preset arc length, using the changed arc length as the current preset arc length, returning the preset arc length of the first clothoid as the current preset arc length, and performing an operation of determining the initial second end point of the first clothoid based on the current preset arc length until the radius of the target circular arc is equal to the instantaneous radius, and using the last initial second end point as the second end point of the first clothoid;

[0201] A fourth determination unit, for determining the midpoint of the target circular arc; wherein, the center of the circle where the target circular arc is located is the target intersection point, and the first end point of the target circular arc is the second end point of the first clothoid;

[0202] A symmetry unit, for performing a symmetry operation on the target curve based on the connection line between the midpoint of the target circular arc and the target intersection point to obtain a combination of a first clothoid - target circular arc - second clothoid; wherein, the target curve is a curve obtained by combining a first clothoid and a first circular arc based on the first end point and the second end point of the first clothoid; the first circular arc is the circular arc between the second end point of the first clothoid and the midpoint of the target circular arc in the target circular arc.

[0203] In a possible implementation manner, the first determination unit is specifically configured to:

[0204] Determine the center of the circle where the circular arc curve is located based on the following formula:

[0205]

[0206] where x c and y c are respectively the abscissa and ordinate of the center of the circle where the circular arc curve is located; x1, y1 and θ1 are respectively the abscissa, ordinate and course angle of the first end point of the circular arc curve; x2, y2 and θ2 are respectively the ordinates of the second end point of the circular arc curve.

[0207] In a possible implementation manner, the second determination unit is specifically configured to:

[0208] Determine the initial second end point of the first clothoid based on the following formula:

[0209]

[0210] where x, y and θ are respectively the abscissa, ordinate and course angle of the initial second end point of the first clothoid in the coordinate system with the first end point of the circular arc curve as the vertex;

[0211] where A is a parameter of the first clothoid, where,

[0212] Among them, V max is the maximum vehicle speed during parking, D max is the maximum steering wheel angle during parking, O max is the maximum angular speed of the steering wheel during parking, s′ ∈ [0, L min , is the current preset arc length, R min is the minimum turning radius during parking.

[0213] In a possible implementation manner, the third determination unit is specifically configured to:

[0214] Determine the intersection point of the normal line of the initial second endpoint and the target line based on the following formula:

[0215]

[0216] Among them, x o , y o are respectively the abscissa and ordinate of the target intersection point in the coordinate system with the first endpoint of the circular arc curve as the vertex;

[0217] Among them, k s is the slope of the target line; x m , y m are respectively the abscissa and ordinate of the target midpoint in the coordinate system with the first endpoint of the circular arc curve as the vertex.

[0218] In a possible implementation manner, the third determination unit is specifically configured to:

[0219] Determine the length between the target intersection point and the initial second endpoint based on the following formula:

[0220]

[0221] Among them, R cc is the length between the target intersection point and the initial second endpoint, and is used as the radius of the target circular arc.

[0222] In a possible implementation manner, the judgment unit is specifically configured to:

[0223] Judge whether the radius of the target circular arc and the instantaneous radius meet the equal condition based on the following formula:

[0224]

[0225] Among them, ε is a preset error value, r c is the instantaneous radius.

[0226] In a possible implementation manner, the fourth determination unit is specifically configured to:

[0227] Determine the midpoint of the target arc based on the following formula:

[0228]

[0229] where α is the semi-central angle of the target arc; x h , y h and θ h are respectively the abscissa, ordinate and heading angle of the midpoint of the target arc in a coordinate system with the first endpoint of the arc curve as the vertex; is the vector from the target intersection point to the target midpoint, is the vector from the target intersection point to the second endpoint of the first clothoid.

[0230] In a possible implementation manner, the symmetry unit is specifically configured to:

[0231] Determine the symmetric point of the second endpoint of the first clothoid symmetric about the target symmetry line; wherein, the target symmetry line is the connection line between the midpoint of the target arc and the target intersection point;

[0232] Determine the second clothoid symmetric about the target symmetry line between the symmetric point and the second endpoint of the arc curve;

[0233] Determine the second arc symmetric about the target symmetry line between the midpoint of the target arc and the symmetric point;

[0234] The first clothoid, the first arc, the second arc and the second clothoid form a combination of the first clothoid - target arc - second clothoid.

[0235] In a possible implementation manner, determining the symmetric point of the second endpoint of the first clothoid symmetric about the target symmetry line includes:

[0236] Determine the symmetric point based on the following formula:

[0237]

[0238] where, and are respectively the abscissa and ordinate of the symmetric point in a coordinate system with the first endpoint of the arc curve as the vertex.

[0239] As Figure 22As shown in the figure, an embodiment of the present application provides an electronic device, including a processor 111, a communication interface 112, a memory 113, and a communication bus 114. Among them, the processor 111, the communication interface 112, and the memory 113 complete communication with each other through the communication bus 114.

[0240] The memory 113 is used to store computer programs.

[0241] In an embodiment of the present application, when the processor 111 is used to execute the program stored on the memory 113, it implements the parking path processing method provided in any of the foregoing method embodiments, including:

[0242] Obtain the initial parking path of the vehicle, and determine the driving action sequence of the initial parking path, where the driving action sequence includes the driving actions corresponding to each path node in the initial parking path;

[0243] When it is determined based on the driving action sequence that the initial parking path is a one-step parking path, determine the circular arc curve in the initial parking path according to the curvature of each path node in the initial parking path;

[0244] Process the circular arc curve into a combination of a first clothoid - target circular arc - second clothoid, where the first endpoint of the first clothoid is the first endpoint of the circular arc curve, and the instantaneous radius of the first clothoid at the second endpoint is equal to the radius of the target circular arc; the first clothoid and the second clothoid are symmetric about the connection line between the midpoint of the target circular arc and the center of the circle where the target circular arc is located;

[0245] Determine the final parking path according to the combination of the first clothoid - target circular arc - second clothoid and the straight-line part in the initial parking path.

[0246] An embodiment of the present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the steps of the parking path processing method provided in any of the foregoing method embodiments.

[0247] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated. The components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0248] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a general hardware platform, and of course, it can also be implemented by hardware. Based on such an understanding, the essence of the above technical solution, or the part that contributes to the related technology, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0249] It should be understood that the terms used herein are for the purpose of describing specific example embodiments only and are not intended to be limiting. Unless the context clearly indicates otherwise, as used herein, the singular forms "a", "an", and "the" may also include the plural forms. The terms "comprising", "including", "containing", and "having" are inclusive and thus specify the presence of the stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or their combinations. The method steps, processes, and operations described herein are not to be construed as necessarily requiring them to be performed in the particular order described or illustrated, unless the order of performance is explicitly stated. It should also be understood that additional or alternative steps may be used.

[0250] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but rather will be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A parking path processing method, characterized in that, Including: Obtain an initial parking path of a vehicle and determine a driving action sequence of the initial parking path, where the driving action sequence includes driving actions corresponding to each path node in the initial parking path; When it is determined that the initial parking path is a one-step parking path based on the driving action sequence, determine an arc curve in the initial parking path according to the curvature of each path node in the initial parking path; Process the arc curve into a combination of a first clothoid - target arc - second clothoid, where a first endpoint of the first clothoid is a first endpoint of the arc curve, and an instantaneous radius of the first clothoid at a second endpoint is equal to the radius of the target arc; the first clothoid and the second clothoid are symmetric about a line connecting the midpoint of the target arc and the center of the circle where the target arc is located; Determine a final parking path according to the combination of the first clothoid - target arc - second clothoid and a straight-line part in the initial parking path.

2. The method according to claim 1, wherein The determining the driving action sequence of the initial parking path includes: Obtain path parameters of each path node in the initial parking path, where the path parameters include coordinate information and a heading angle; Perform the following processing for each path node in the initial parking path: Based on the path parameters of the path node and the path parameters of its next path node, determine a moving direction angle of the next path node relative to the path node; Determine a driving gear corresponding to the path node based on the moving direction angle; Sort the driving gears corresponding to multiple path nodes in the order of the multiple path nodes to obtain the driving action sequence of the initial parking path.

3. The method according to claim 2, wherein The determining the driving gear corresponding to the path node based on the moving direction angle includes: Determine the driving gear corresponding to the path node based on the following formula: where S i is the driving gear corresponding to the i-th path node, 1 represents reverse gear, and 0 represents forward gear; θ r is the moving direction angle, x i , y i are respectively the abscissa and ordinate of the i-th path node, x i+1 , y i+1 are respectively the abscissa and ordinate of the (i + 1)-th path node.

4. The method according to claim 3, characterized in that, The determining that the initial parking path is a one-step parking path based on the driving action sequence includes: When the following formula holds, determine that the initial parking path is a one-step parking path: where N is the number of the path nodes, and S i+1 is the driving gear corresponding to the (i + 1)-th path node.

5. The method according to claim 1, characterized in that, The determining the arc curve in the initial parking path according to the curvature of each path node in the initial parking path includes: For a non-first path node in the initial parking path, determine whether the curvature of the path node and the curvature of its previous path node satisfy a preset equal condition; When the curvature of the path node and the curvature of its previous path node do not satisfy the equal condition, determine the path node as a curvature mutation point; Determine a non-straight path segment between the curvature mutation point and its adjacent path node as the arc curve in the initial parking path.

6. The method according to claim 1, wherein The processing each arc curve into a combination of a first clothoid - target arc - second clothoid includes: For each arc curve, determine the center of the circle where the arc curve is located and determine a target line passing through the center of the circle where the arc curve is located and a target midpoint, where the target midpoint is the midpoint of a line segment formed by two endpoints of the arc curve; Take the first endpoint of the arc curve as the first endpoint of the first clothoid curve, and preset the arc length of the first clothoid curve as the current preset arc length. Based on the current preset arc length, determine the initial second endpoint of the first clothoid curve; Determine the intersection point of the normal line passing through the initial second endpoint and the target straight line as the target intersection point, and determine the length between the target intersection point and the initial second endpoint as the radius of the target arc; Judge whether the radius of the target arc and the instantaneous radius of the first clothoid curve at the initial second endpoint meet the equal condition; If not, change the current preset arc length, take the changed arc length as the current preset arc length, and return to the operation of presetting the arc length of the first clothoid curve as the current preset arc length and determining the initial second endpoint of the first clothoid curve based on the current preset arc length until the radius of the target arc and the instantaneous radius meet the equal condition, and take the last initial second endpoint as the second endpoint of the first clothoid curve; Determine the midpoint of the target arc; wherein, the center of the circle where the target arc is located is the target intersection point, and the first endpoint of the target arc is the second endpoint of the first clothoid curve; Perform a symmetry operation on the target curve based on the connection line between the midpoint of the target arc and the target intersection point to obtain a combination of the first clothoid curve - target arc - second clothoid curve; wherein, the target curve is a curve obtained by combining the first clothoid curve and the first arc based on the first endpoint and the second endpoint of the first clothoid curve; the first arc is the arc between the second endpoint of the first clothoid curve and the midpoint of the target arc in the target arc.

7. The method according to claim 6, wherein The determining the initial second endpoint of the first clothoid curve based on the current preset arc length includes: Determine the initial second endpoint of the first clothoid curve based on the following formula: wherein, x, y and θ are respectively the abscissa, ordinate and heading angle of the initial second endpoint of the first clothoid curve in the coordinate system with the first endpoint of the arc curve as the vertex; where A is the parameter of the first clothoid, where Among them, V max is the maximum vehicle speed during parking, D max is the maximum steering wheel angle during parking, O max is the maximum angular speed of the steering wheel during parking, s ′ ∈[0, L min , is the current preset arc length, R min is the minimum turning radius during parking.

8. The method according to claim 6, wherein The judging whether the difference between the radius of the target arc and the instantaneous radius of the first clothoid curve at the initial second endpoint meets the equal condition includes: Judge whether the radius of the target arc and the instantaneous radius meet the equal condition based on the following formula: where R cc is the radius of the target circular arc, ε is a preset error value, r c is the instantaneous radius, and A is a parameter of the first clothoid, where, Among them, V max is the maximum vehicle speed during parking, D max is the maximum steering wheel angle during parking, O max is the maximum angular speed of the steering wheel during parking, s ′ ∈[0, L min , is the current preset arc length, R min is the minimum turning radius during parking.

9. The method according to claim 6, wherein The performing a symmetry operation on the target curve based on the connection line between the midpoint of the target arc and the target intersection point to obtain a combination of the first clothoid curve - target arc - second clothoid curve includes: Determine the symmetric point of the second endpoint of the first clothoid curve symmetric about the target symmetry line; wherein, the target symmetry line is the connection line between the midpoint of the target arc and the target intersection point; Determine the second clothoid curve symmetric about the target symmetry line of the first clothoid curve between the symmetric point and the second endpoint of the arc curve; Determine the second arc symmetric about the target symmetry line of the first arc between the midpoint of the target arc and the symmetric point; The first clothoid, the first circular arc, the second circular arc, and the second clothoid form a combination of a first clothoid - target circular arc - second clothoid.

10. The method according to claim 9, wherein Determining the symmetric point of the second endpoint of the first clothoid symmetric with respect to the target symmetry line includes: Determining the symmetric point based on the following formula: wherein, and are respectively the abscissa and ordinate of the symmetric point in a coordinate system with the first endpoint of the circular arc curve as the vertex.

11. A parking path processing device, characterized in that, Including: A driving action determination module, configured to obtain an initial parking path of a vehicle and determine a driving action sequence of the initial parking path, where the driving action sequence includes driving actions corresponding to each path node in the initial parking path; A circular arc curve determination module, configured to, when it is determined based on the driving action sequence that the initial parking path is a one-step parking path, determine a circular arc curve in the initial parking path according to the curvature of each path node in the initial parking path; A circular arc curve processing module, configured to process the circular arc curve into a combination of a first clothoid - target circular arc - second clothoid, where a first endpoint of the first clothoid is a first endpoint of the circular arc curve, and an instantaneous radius of the first clothoid at a second endpoint meets an equal condition with the radius of the target circular arc; the first clothoid and the second clothoid are symmetric based on a connection line between the midpoint of the target circular arc and the center of the circle where the target circular arc is located; A final parking path determination module, configured to determine a final parking path according to the combination of the first clothoid - target circular arc - second clothoid and a straight-line part in the initial parking path.

12. An electronic device, characterized in that, Including: A memory, configured to store a computer program; A processor, configured to execute the computer program stored in the memory, and when the computer program is executed, implement the method according to any one of claims 1 - 10 above.

13. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, implement the method according to any one of claims 1 - 10 above.

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