Dynamic critical zone division method for intersection and electronic device

Abstract

The application discloses a dynamic critical area division method for an intersection and an electronic device, belongs to the field of automatic driving, and aims to solve the driving planning problem of a vehicle passing through an intersection and be applicable to a complex intersection. The method comprises the following steps: acquiring a virtual path according to a starting lane and a destination lane; acquiring an actual path according to the virtual path; and acquiring a virtual critical area sequence according to the actual path, wherein the virtual critical area sequence is an area that needs to be occupied by the vehicle when passing through the intersection. The method has the effect that the virtual critical area sequence is acquired according to the actual path, the vehicle is driven according to the planned virtual critical area sequence, the non-standard intersection can be adapted to by means of sequence division, and the vehicle driving path planning of the application can be applied to the complex intersection.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of automatic driving, and relates to a dynamic critical area division method for an intersection, in particular to a division method capable of intelligently generating a dynamic critical area according to intersection conditions and vehicle types. BACKGROUND

[0002] With the rapid development of economy and the continuous acceleration of urbanization, the number of cars and the amount of road traffic are increasing rapidly, and traffic problems such as traffic congestion, driving safety and environmental pollution are becoming increasingly serious. Using technologies such as Internet of Vehicles, vehicle-road / vehicle-cloud and traffic big data to alleviate traffic congestion has become an important technical direction and development trend in the field of transportation.

[0003] As an important hub of the road traffic network, the intersection is the most congested and complex scene in road traffic, and the traffic dispersal capacity directly affects the overall traffic efficiency and safety of the road. Therefore, even if the vehicle can improve the traffic efficiency in normal road driving, if it cannot achieve efficient use of road resources in the intersection area, the entire traffic system will be trapped in the "barrel effect", and congestion will still form in a specific area, thereby reducing the overall traffic efficiency. In view of the intersection congestion problem, many researchers have made targeted research.

[0004] The document "Research on QoS-oriented continuous critical area unmanned vehicle cooperative scheduling mechanism[D]. Yang Ansheng. Northwestern Polytechnical University, 2017." studies an intersection scheduling scheme based on static critical area. However, it only proposes a critical area division scheme for standard crossroads, and uses a coarse-grained critical area, which has a low road utilization rate. The document "Research on unmanned vehicle intersection scheduling strategy for intelligent driving[D]. Mo Yang'an. Harbin Institute of Technology, 2020." proposes a scheduling scheme in a standard intersection connected by four two-way two-lane roads. However, its scheme also lacks universality and is difficult to apply to a large number of non-standard intersections. At the same time, the above-mentioned schemes cannot adjust the vehicle path according to the vehicle attributes and real-time conditions, which has a relatively large limitation. SUMMARY

[0005] In order to solve the problem that the driving planning of the vehicle passing through the intersection can be applied to complex intersections, the dynamic critical area division method for an intersection according to some embodiments of the application comprises

[0006] S100. obtaining a virtual path VP according to a starting lane SL and a destination lane AL;

[0007] S200. obtaining an actual path AP according to the virtual path VP;

[0008] S300. Obtain a virtual critical area VCA sequence according to the actual path AP, the virtual critical area VCA sequence being an area that needs to be occupied by the vehicle when passing through the intersection.

[0009] The method for dividing dynamic critical areas of an intersection according to some embodiments of the present application, the method for obtaining a virtual path VP according to a starting lane SL and a destination lane AL in step S100, comprises

[0010] S110. Determine whether the starting lane center line CL SL and the destination lane center line CL AL are on the same straight line to determine the method for generating the virtual path VP;

[0011] If the starting lane center line CL SL and the destination lane center line CL AL are on the same straight line, generate the virtual path VP in a first method, and execute step S120;

[0012] If the starting lane center line CL SL and the destination lane center line CL AL are not on the same straight line, generate the virtual path VP in a second method, and execute step S130;

[0013] S120. Generate the virtual path VP in the first method: the starting lane center line CL SL and the connection point CP SL of the intersection, the destination lane center line CL AL and the connection point CP AL of the intersection, and the connection line between the connection point CP SL and the connection point CP AL is the virtual path VP;

[0014] S130. Generate the virtual path VP in the second method:

[0015] S131. Calculate the coordinates of control points P1 and P2, the control point P1 being a point on the extension line of the starting lane center line CL SL towards the inside of the intersection and having a distance D1 from the connection point CP SL , and the control point P2 being a point on the extension line of the destination lane center line CL AL towards the inside of the intersection and having a distance D2 from the connection point CP AL ;

[0016] S132. Take the connection point CP SL , the control point P1, the control point P2, and the connection point CP ALa third order Bezier curve is drawn, the Bezier curve being a virtual path VP.

[0017] According to the dynamic critical area division method of the intersection according to some embodiments of the present application, the actual path AP is a polyline connected by a plurality of line segments whose start points and end points are on the virtual path VP or the destination lane center line CL AL k k The length of the line segment PSL k k is a positive integer. k The length of the line segment PSL k k is a positive integer.

[0018] The method for obtaining the actual path AP according to the virtual path VP in step S200 comprises:

[0019] S210. Taking the connection point CP SL as the start point of the kth line segment PS k of the actual path AP, at this time, k = 1.

[0020] S220. Calculating the length PSL k of the kth line segment PS k of the actual path AP.

[0021] S230. Finding a point on the virtual path VP in the positive direction of the virtual path VP and having a distance PSL k from the start point of the kth line segment PS k of the actual path AP.

[0022] If the point exists, step S240 is performed.

[0023] If the point does not exist, step S250 is performed.

[0024] S240. Taking the point in step S230 as the end point of the kth line segment PS k of the actual path AP, taking the end point of the kth line segment PS k of the actual path AP as the start point of the (k+1)th line segment PS k+1 of the actual path AP, increasing k by 1, and performing step S220.

[0025] S250. Judging whether the start point of the kth line segment PS k of the actual path AP coincides with the connection point CP AL .

[0026] ​​If we determine that the k-th line segment PS constitutes the actual path AP k The starting point and the connection point CP AL Overlapping, the actual path AP is from PS1 to PS k-1 The actual path AP has been generated;

[0027] If we determine that the k-th line segment PS constitutes the actual path AP k The starting point and the connection point CP AL Not overlapping, on the center line CL of the destination lane AL Find the k-th line segment PS that forms the actual path AP. k The starting distance is PSL k The point is used as the k-th line segment PS that constitutes the actual path AP. k The destination, the actual path AP is from PS1 to PS k The actual path AP has been generated.

[0028] According to some embodiments of the dynamic critical section division method for intersections in this application, the virtual path VP is determined by, for example...

[0029] The following formula represents B(t), which denotes a cubic Bézier curve:

[0030] B(t)=(1-t) 3 P0+3t(1-t) 2 P1+3t 2 (1-t)P2+t 3 P3

[0031] Where t takes values ​​in the range [0, 1], and P0 represents the connection point CP. SL P1 represents control point P1, P2 represents control point P2, and P3 represents connection point CP. AL The positions of P1 and P2 are changed by adjusting the distances D1 and D2.

[0032] According to the dynamic critical zone division method of intersections in some embodiments of this application, the k-th line segment PS constitutes the actual path AP. k Length of PSL k It can be expressed by the following formula:

[0033]

[0034] β0 is a positive floating-point number, β1 is a positive constant, and P k For PS k The starting point is C(P), which is the curvature of the virtual path VP at point P, and VL represents the vehicle length.

[0035] According to the dynamic critical zone division method for intersections in some embodiments of this application, the i-th virtual critical zone generated along the positive direction of the actual path AP is denoted as VCA. i Where i is a positive integer, the area occupied by the vehicle body is approximately a rectangle RA, the length VL of rectangle RA represents the vehicle length, and the width VW of rectangle RA represents the vehicle width. The rectangle RA is the initial virtual critical region VCA. i ;

[0036] The initial virtual critical section VCA i The long VL extends the safety distance SD in front of the vehicle. Head The wide VW extends the safety distance SD on both sides of the vehicle. Side The resulting new rectangle is the virtual critical region VCA. i Safe distance SD Side If the value is positive, the safety distance SD Side The maximum value is half the difference between the lane width and the width VW, and the safety distance SD is... Head The initial virtual critical section VCA is a non-negative number. i MP is the midpoint of the leading edge in the vehicle direction. Head MP is located at the midpoint of the trailing edge in the vehicle direction. Back ;

[0037] The method for obtaining the virtual critical section (VCA) sequence based on the actual path AP in step S300 includes:

[0038] S310. PS is the kth line segment that constitutes the actual path AP. k The connection point CP at the starting point SL It serves as the initial virtual critical section VCA i MP at the midpoint of the trailing edge in the vehicle direction Back At this point, i = 1, k = 1;

[0039] S320. Find the k-th line segment PS that constitutes the actual path AP. k Positive direction, destination lane centerline CL AL Above and the initial virtual critical section VCA i MP at the midpoint of the trailing edge in the vehicle direction Back A point at a distance of VL,

[0040] If found, proceed to step S330;

[0041] If not found, increment k by 1 and repeat step S320;

[0042] S330. Using the point mentioned above as the initial virtual critical region VCA i MP at the midpoint of the leading edge in the vehicle direction Head According to the initial virtual critical section VCAi MP at the midpoint of the trailing edge in the vehicle direction Back and at the midpoint of the leading edge in the vehicle direction MP Head The location is used to generate the initial virtual critical section VCA. i The initial virtual critical section VCA i It is a safe distance SD Head Safe distance SD Side Virtual critical section VCA with a value of 0 i ;

[0043] S340. Determine the initial virtual critical section (VCA). i MP at the midpoint of the leading edge in the vehicle direction Head Is it on the center line CL of the destination lane? AL superior,

[0044] If the initial virtual critical section VCA sequence has been generated, proceed to step S360.

[0045] If not, proceed to step S350;

[0046] S350. Initial Virtual Critical Section VCA i MP at the midpoint of the leading edge in the vehicle direction Head As the initial virtual critical section VCA i+1 MP at the midpoint of the trailing edge in the vehicle direction Back Increment i by 1 and execute step S320;

[0047] S360. Let i = 1;

[0048] S370. Calculate the initial virtual critical section VCA i Safe distance SD Head According to the safety distance SD Head Generate Virtual Critical Section (VCA) i ;

[0049] S380. Determine the initial virtual critical section (VCA) i Is this the last initial virtual critical section (VCA)?

[0050] If not, increment i by 1 and proceed to step S370;

[0051] If so, the virtual critical section (VCA) sequence has been generated.

[0052] According to the dynamic critical zone division method for intersections in some embodiments of this application, the safety distance SD Head It can be expressed by the following formula:

[0053]

[0054] wherein θ is the angle between the leading edge of the initial virtual critical area VCA i and the trailing edge of the initial virtual critical area VCA i+1 , the safety distance SD i of the last initial virtual critical area VCA Head is 0.

[0055] According to the dynamic critical area division method of the intersection of some embodiments of the present application, if the obstruction is in the first virtual critical area of the virtual critical area VCA sequence allocated to the first vehicle, a temporary virtual critical area is allocated to the first vehicle for driving and stopping, which does not contain the obstruction, occupies part of the first virtual critical area and the previous virtual critical area of the first virtual critical area in the virtual critical area VCA sequence allocated to the first vehicle, and does not overlap with the virtual critical area in the virtual critical area VCA sequence allocated to other vehicles, if there is a gap between the temporary virtual critical area and the first critical area, a corresponding safety distance SD Head is added to the temporary virtual critical area to fill the gap, and if there is no gap between the temporary virtual critical area and the first critical area, the value of the safety distance SD Head is 0.

[0056] According to the dynamic critical area division method of the intersection of some embodiments of the present application, the obstruction includes a second vehicle, the virtual critical area VCA sequence allocated to the first vehicle has partial overlap with one virtual critical area in the virtual critical area VCA sequence allocated to the second vehicle, the virtual critical area in the virtual critical area VCA sequence of the first vehicle with the overlap is the first virtual critical area, and the virtual critical area in the virtual critical area sequence of the second vehicle with the overlap is the second virtual critical area, if the second vehicle stops in the second virtual critical area, a temporary virtual critical area is allocated to the first vehicle to completely drive and stop in the temporary virtual critical area, the temporary virtual critical area occupies part of the first virtual critical area and the previous virtual critical area of the first virtual critical area, but does not overlap with the second virtual critical area, if there is a gap between the temporary virtual critical area and the first critical area, a corresponding safety distance SD Head is added to the temporary virtual critical area to fill the gap, and if there is no gap between the temporary virtual critical area and the first critical area, the value of the safety distance SD Head is 0.

[0057] The electronic device includes one or more processors, a memory, and one or more programs; the one or more programs are stored in the memory, and the one or more programs include instructions, which, when executed by the electronic device, cause the electronic device to perform any possible technical solutions related to the embodiments of the present application.

[0058] The technical effects of each aspect in the above-mentioned second aspect and each aspect can be achieved are described above in relation to the technical effects that can be achieved by the various possible solutions of the first aspect, and will not be repeated here.

[0059] Advantages of the present application:

[0060] In the first aspect, the virtual critical area VCA sequence is obtained according to an actual path, so that the vehicle travels according to the planned virtual critical area VCA sequence, and through the sequence division manner, the non-standard intersection can be adapted, so that the present application can be applied to the complex intersection for vehicle driving path planning.

[0061] In the second aspect, compared with the existing way of planning a vehicle driving path by dividing a road into zones, the present application takes the vehicle as an object, draws a cubic Bezier curve through the connection point CP SL , the control point P1, the control point P2 and the connection point CP AL , uses the vehicle as a planning object, and makes the planned virtual path dynamic through the variability of the control points P1 and P2, and can also eliminate or reduce the conflict area, thereby improving the traffic efficiency.

[0062] In the third aspect, in order to improve the applicability of the virtual path VP, the way of generating the virtual path VP is determined according to the intersection condition, the virtual path is obtained in different ways for different applicable situations, so that the virtual path generation is targeted and accurate.

[0063] In the fourth aspect, the present application considers the complexity of Bezier curve calculation, especially the existing planning system generally uses a special computer set at the intersection, and the operation ability of the special computer is limited due to the current technical level, therefore, the present application realizes the virtual path VP to obtain the actual path AP through the line segment fitting Bezier curve manner, so that the virtual critical area VCA sequence of the present application is realized on the basis of the line segment fitting Bezier curve manner, compared with the curve calculation, the calculation complexity can be reduced.

[0064] In the fifth aspect, the present application is based on the line segment fitting Bezier curve method for forming the virtual critical area. In the first stage, a temporary virtual critical area sequence is generated. On this basis, a safety distance is further set for each temporary virtual critical area, and then a virtual critical area sequence is generated. Therefore, the temporary virtual critical area sequence of the present application can plan a feasible path, and on this basis, the included angle between the front edge and the rear edge of two temporary virtual critical areas can be accurately obtained. The safety distance is accurately defined through the included angle, and the gap between different temporary virtual critical areas can be more accurately avoided, thereby eliminating the safety hazard.

[0065] In the sixth aspect, in the use of the present application, the dynamic critical area division of the present application further considers the case that a vehicle or other object stays in the virtual critical area sequence of the vehicle. For vehicle stopping, it should generally stop in the RA area in a certain VCA allocated to it to release other VCAs and provide passing space for the remaining vehicles. However, if an obstacle is detected in the front VCA during passing, in order to avoid collision, it often needs to stay at a temporary position, which often occupies two VCAs, causing waste of the intersection area. In order to avoid this situation, a driving and stopping position that will not cause collision is calculated by the vehicle or other responsible scheduling device, and then a temporary virtual critical area TVCA is generated at the position. After the vehicle stops inside the TPCA, other VCAs can be released for other vehicles to pass. BRIEF DESCRIPTION OF DRAWINGS

[0066] Figure 1 The points used in the present application include the connection points CP, the control points P1 and P2, the lane center line CL, the distribution of the generated VCA sequence in a standard cross intersection, and the effect diagram of the VCA.

[0067] Figure 2 The schematic diagram of various virtual paths VP generated in a special-shaped intersection.

[0068] Figure 3 The flowchart of the dynamic critical area proposed in the present application.

[0069] Figure 4 The schematic diagram of the temporary virtual critical area of the present application. DETAILED DESCRIPTION

[0070] The embodiments of the present application are described in detail below with reference to the accompanying drawings, examples of which are shown in the drawings. The present application provides a method and an electronic device to solve the problem that the driving planning of vehicles passing through an intersection can be applied to complex intersections. The method, device, and computer readable storage medium are based on the same technical concept. Since the principles of solving the problem are similar, the embodiments can be referred to each other, and the repeated parts will not be described again.

[0071] This invention provides a method for dynamically defining critical zones at intersections. For ease of description, the starting lane is abbreviated as starting lane SL, and the centerline of the starting lane is abbreviated as CL. SL , CL SL The connection point with the intersection is named CP. SL The destination lane AL is abbreviated as AL, and the center line of the destination lane AL is abbreviated as CL. AL , CL AL The connection point with the intersection is named CP. AL It should be emphasized that this method only considers a small section of road connecting to an intersection, whose centerline can be approximated as a straight line.

[0072] In this invention, an intersection refers to a planar intersection, that is, a location where two or more roads intersect on the same plane. A virtual path VP is defined, which serves as the basis for calculating the actual path. Since this method uses a cubic Bézier curve as the virtual path VP, the subsequent calculation of the vehicle critical zone is computationally intensive. Therefore, an actual path AP is generated based on the virtual path VP for actual vehicle travel. The actual path AP is a polyline consisting of several paths whose starting and ending points are both on the virtual path VP or CL. AL The virtual path (P) is formed by connecting line segments, and these line segments are named PS (PolylineSegment). The length of each line segment is named P (Initial Lane SL). The vehicle's direction of travel is defined as the positive direction of both the virtual path (VP) and the actual path (AP).

[0073] In this invention, the area occupied by a vehicle when passing through an intersection is called the virtual critical area sequence. The basic unit of this sequence is the virtual critical area (VCA). The specific details of the virtual critical area (VCA) are as follows: the area occupied by the vehicle body is approximated as a rectangle and named RA (Real Area). Its length is the vehicle length (VL), and its width is the vehicle width (VW). Based on this, the virtual critical area (VCA) is defined by adding a safety distance (SD) on both sides of the RA. Side (SafeDistance), and add a safe distance SD in front of the vehicle. Head It needs to be emphasized that SD Side It is a positive number, with a maximum value of half the difference between the lane width and VW. SD Head It is a non-negative number. Adding a safety distance ensures that the vehicle remains within the virtual critical zone (VCA) sequence during travel, thus preventing collisions. For ease of explanation later, RA is named MP based on the midpoint of its leading edge in the vehicle's direction. Head The midpoint of the trailing edge is named MP.Back As shown in Figure 1 .

[0074] For the convenience of description, some terms used below are explained:

[0075] PS k : that is, the kth line segment of the actual path AP, k is a positive integer.

[0076] PSL k : that is, the length of the PS k , k is a positive integer.

[0077] VCA i : that is, the ith virtual critical area VCA generated in the positive direction of the actual path AP, i is a positive integer.

[0078] The dynamic critical area division process in the present application is divided into three parts, which will be briefly described as follows:

[0079] First step: generating a virtual path VP according to the conditions of the starting lane SL and the AL:

[0080] First, before starting to generate the virtual path VP, the information of the starting lane center line CL SL , the connection point CP SL of the starting lane center line CL SL and the intersection, the destination lane center line CL AL and the connection point CP AL of the destination lane center line CL AL and the intersection needs to be known. In this method, according to the conditions of the starting lane SL and the destination lane AL AL and the relationship between them, the virtual path VP generation method is divided into the following two types:

[0081] 1. If CL SL and CL AL are on the same straight line, it is the first type of passing mode, and the virtual path VP is the connecting line of CP SL and CP AL .

[0082] 2. Otherwise, it belongs to the second type of passing mode, and the virtual path VP is a cubic Bezier curve drawn with four control points of P1, P2 and CP AL , which are points on the extension line of CP SL , CL SL towards the inside of the intersection with a distance D1 from CP SL , CL AL towards the inside of the intersection with a distance D2 from CP AL and CP AL . The curve is the virtual path VP.

[0083] where the cubic Bezier curve formula is:

[0084] B(t) = (1-t) 3 P0+3t(1-t) 2 P1+3t 2 (1-t)P2+t 3 P3

[0085] In the formula, the value range of t is [0, 1]. P0 to P3 are four control points.

[0086] The positions of P1 and P2 used in the generation process of the second type of virtual path VP can be changed by adjusting the sizes of D1 and D2. This is to adapt to the traffic demand of different vehicles and to realize conflict avoidance when different vehicles pass through the intersection.

[0087] Second, generate the actual path AP according to the virtual path VP and the attributes of the passing vehicles:

[0088] After the virtual path VP is determined, the second step of generating the actual path AP is started.

[0089] CP SL As the starting point of the first PS, generate a sequence of line segments connected at both ends along the virtual path VP, i.e., the actual path AP. The starting point and the ending point of each line segment need to be on the virtual path VP or CL AL above. During the generation process, if it is found that the ending point of a newly generated line segment is on CL AL , then this line segment is the last line segment constituting the actual path AP.

[0090] The length of the line segment is calculated by the formula:

[0091]

[0092] β0 is a positive floating point number, β1 is a normal number, P i is the starting point of the PS i , and C(P) is the curvature of the virtual path VP at point P.

[0093] Third, generate the virtual critical area VCA sequence according to the actual path AP:

[0094] After the actual path AP is generated, the last step of generating the virtual critical area VCA sequence needs to be performed. Similar to the second step, the third step takes CP SL as the MP Back of the first virtual critical area VCA, generates the MP Head of the previous virtual critical area VCA along the actual path AP, and generates the MP BackOverlapping virtual critical section (VCA) sequences, MP of each virtual critical section (VCA) Head and MP Back Both AP and CL need to be in the actual path. AL Up. If a newly generated virtual critical section VCA's MP is found... Head In CL AL If the above is true, then this virtual critical section VCA is the last virtual critical section VCA of the sequence. At this point, the SD of all generated virtual critical sections VCAs... Head All are 0. To avoid gaps between virtual critical regions (VCAs), the required SD for each virtual critical region VCA is calculated. Head And add it to the corresponding virtual critical section VCA.

[0095] SD Head The specific calculation formula is as follows:

[0096]

[0097] Where θ is VCA i Leading edge and VCA i+1 The included angle at the trailing edge. As for the first and last virtual critical zones (VCA), since the gap between this critical zone and AL is unlikely to be occupied by vehicles from other lanes, the corresponding SD... Head Set to 0.

[0098] This method considers the situation where vehicles may need to temporarily stop inside an intersection due to obstacles or other reasons, potentially occupying two Virtual Critical Areas (VCAs) and thus affecting the traffic efficiency of other vehicles. To mitigate this problem, a temporary virtual critical area is defined. When a vehicle needs to stop inside the intersection for some reason, a temporary virtual critical area is generated based on its stopping position. At this time, it can choose to release all other virtual critical area VCAs it occupies, making them available for other vehicles. If the vehicle needs to continue moving, it must reapply for virtual critical area VCAs.

[0099] like Figure 4, assuming VCA2, VCA3, VCA4 are part of the VCA sequence assigned to vehicle A, vehicle B stops at VCA1 for some reason, and VCA1 overlaps with VCA3, therefore when vehicle A finds that it is possible to have a collision when entering VCA3, it can choose to stay at VCA4 or stay at the junction of VCA3 and VCA4. Choosing to stay at VCA4 can release a part of the road area, but the area in VCA3 that does not overlap with VCA1 is likely to be wasted. Staying at the junction of VCA3 and VCA4 will result in both VCA3 and VCA4 being unable to release, also wasting a lot of road area. Therefore, a temporary virtual critical area TVCA scheme is proposed, after the vehicle finds a parking position close to but not colliding according to the ranging device or positioning, a TVCA is generated according to the position, and after vehicle A stays inside the TPCA, other VCAs can be released. If there is a gap between TVCA and VCA2, a safety distance SD Head is added to fill the gap. If there is no gap between TVCA and VCA2, the value of safety distance SD Head is 0.

[0100] As shown in Figure 4 , for the temporary virtual critical area TVCA1 as a temporary virtual critical area, compared to taking the virtual critical area VCA4 as a virtual critical area for driving and stopping, part of the virtual critical area VCA4 in the vehicle VCA sequence is released, which can to some extent more reasonably utilize the planning space and ensure the implementation of the dynamic planning method of the present application.

[0101] The specific technical solutions are as follows:

[0102] The method is not only suitable for standard crossroads and special-shaped intersections shown in the drawings, but also suitable for T-shaped, Y-shaped and various other shaped intersections, and various road types that can be simplified and decomposed into multiple intersections, such as roundabouts. With appropriate scheduling schemes, the method is also suitable for critical area division at the intersection of ramps and main roads.

[0103] The temporary virtual critical area proposed in the method is specially used in the case of encountering a vehicle that needs to stop in the middle of the road due to various unexpected reasons. Because the virtual critical areas VCA generated in the method can overlap with each other, it is easy to have a stopped vehicle occupying two critical areas. Generating a temporary virtual critical area according to the vehicle position and releasing the originally occupied virtual critical area VCA can create good conditions for other vehicles to adjust the trajectory to avoid the stopped vehicle.

[0104] The scheduling process of the present application will be described in detail below in combination with the drawings and embodiments:

[0105] Step A: initialization

[0106] First, initialize the vehicle information and intersection information. This includes vehicle information such as vehicle length (VL) and width (VW), and safety distance (SD). Side and the starting lane centerline CL of the road information SL The starting lane centerline CL SL Connection point CP of the intersection SL CL, the center line of the destination lane AL and the center line of the destination lane CL AL Connection point CP of the intersection AL .

[0107] The basic information required by this method is only the information of the lane the vehicle is about to leave and the lane it is about to enter. This expands the scope of application of this method, making it not limited to a few common intersections.

[0108] Step B: Generate Virtual Path (VP)

[0109] Step B1: According to CL SL and CL AL Choose the virtual path (VP) generation method based on the following conditions: Determine CL SL and CL AL Check if they are on the same straight line. If they are on the same straight line, proceed to step B2; otherwise, proceed to step B3.

[0110] Step B2: Generation of the first type of virtual path (VP): CP SL With CP AL The connecting line is the virtual path VP. Then proceed to step C.

[0111] According to the above scheme, when CL SL and CL AL When the lines are on the same straight line, use the simplest calculation method to reduce the computational burden.

[0112] Step B3: Generation of the second type of virtual path (VP):

[0113] Step B3.1: Calculate the coordinates of control points P1 and P2: Calculate CL SL Extending the line into the intersection and CP SL Points P1 and CL are distances from D1 AL Extending the line into the intersection and CP AL Find the coordinates of point P2, which is a distance from D2. Proceed to step B3.2. In this step, adjust CP... SL Distances D1 and CP from point P1 AL The distance D2 from point P2 can be used to adjust the positions of the two control points P1 and P2, thereby controlling the shape and position of the generated VL. This can eliminate conflicts or reduce the conflict area, thus improving traffic efficiency.

[0114] Step B3.2: Draw a cubic Bezier curve: draw a cubic Bezier curve with CP SL , P1, P2 and CP AL as control points. The curve is the virtual path VP. Perform step C.

[0115] Step C: Generate the actual path AP. In this step, the purpose of generating the actual path AP is to reduce the amount of calculation. Since this method uses a lot of cubic Bezier curves, calculating the actual path AP first and then calculating the virtual critical area VCA sequence based on the actual path AP can significantly reduce the amount of calculation. If the computing capacity is sufficient, the virtual critical area VCA sequence can also be calculated directly based on the virtual path VP.

[0116] Step C1: Prepare to generate the first PS: let k = 1, take CP SL as the starting point of PS k , and perform step C2.

[0117] Step C2: Calculate PSL k : Calculate the length PSL k of PS k , and perform step C3.

[0118] Obviously, the smaller the average of P starting lane SL, the more the polyline sequence conforms to the virtual path VP, the more natural the vehicle trajectory, and the more the amount of calculation. The larger the average of P starting lane SL, the greater the deviation of the polyline sequence from the virtual path VP, the less natural the vehicle trajectory, and the smaller the amount of calculation. When a large number of P starting lanes SL are too small, the function of reducing the amount of calculation is lost. When a large number of P starting lanes SL are too large, it will cause the angle between two adjacent PSs to become large, which is not conducive to vehicle traffic. Therefore, this method introduces curvature and VL when calculating PSL k , and adjusts the parameters to achieve the effect of generating a smaller PS length in the part of the virtual path VP with a large degree of curvature and a larger PS length in the part with a small degree of curvature, while also reducing the calculation pressure.

[0119] Step C3: Find the end point of PS k : find a point on the virtual path VP in the positive direction that is PSL k away from the starting point of PS k . If such a point exists, perform step C4. If not, perform step C5.

[0120] Step C4: Generate PS k and prepare to generate PS k+1

[0121] Take the point as the end point of PS k ​The endpoint, PS k The endpoint as PS k+1 Find the starting point, and then increment k by 1. Execute step C2.

[0122] Step C5: Determine whether the actual path AP has been generated and take appropriate action: Determine the PS k Is the starting point related to CP? AL If they overlap, the actual path AP is generated, and step D is executed. If they do not overlap, proceed to step CL. AL Searching for PS k Starting point distance from PSL k Points as PS k The endpoint. Then proceed to step D.

[0123] Step D: Generate the virtual critical section (VCA) sequence:

[0124] Step D1: Prepare to generate the first virtual critical section (VCA): Let i = 1, k = 1. Using CP... SL That is, PS k The starting point is the MP of the first virtual critical section VCA. Back .

[0125] Step D2: According to MP Back Looking for MP Head In PS k Positive direction and CL AL Search for the MP Back Find the point at distance VL. If found, proceed to step D3. If not found, increment k by 1 and repeat this step.

[0126] Step D3: Generate VCA i Take this point as the VCA i MP Head According to VCA i MP Back and MP Head Location generation SD Head VCA of 0 i .

[0127] Step D4: Determine if the next virtual critical section (VCA) needs to be generated: Determine the VCA i MP Head Is it in CL? AL Above. If in CL AL The virtual critical section (VCA) sequence has been generated. Proceed to step D6. If not, proceed to step D5.

[0128] Step D5: Initialize VCA i+1 VCA i MPHead As VCA i+1 MP Back Increment i by 1. Execute step D2.

[0129] Step D6: Start adding SD cards Head Let i = 1, then execute step D7.

[0130] Step D7: Calculate VCA i Required SD Head : Calculate the SD of the virtual critical section VCA Head Proceed to step D8.

[0131] Step D8: Add the corresponding SD card Head : for VCA i Add the corresponding SD card Head Proceed to step D9.

[0132] The SD card added in this step Head This is to fill the gaps in the virtual critical zone (VCA) sequence, thereby ensuring that the vehicle remains within the critical zone during travel to avoid collisions. The gaps between the first virtual critical zone (VCA) and the starting lane (SL), and the gaps between the last virtual critical zone (VCA) and the lane (AL), are not filled because these locations are unlikely to conflict with vehicles in other lanes.

[0133] Step D9: Determine if traversal is complete: Check VCA i Is this the last virtual critical section (VCA)? If not, increment i by 1 and execute step D7. If yes, the process ends.

[0134] According to the above plan:

[0135] Firstly, the present invention obtains the virtual critical zone (VCA) sequence based on the actual path, enabling vehicles to travel according to the planned virtual critical zone (VCA) sequence. Through the sequence division method, it can adapt to non-standard intersections, making the present invention applicable to vehicle travel path planning at complex intersections.

[0136] Secondly, compared to existing methods that plan vehicle travel routes by dividing roads into zones, this invention focuses on vehicles and uses connection points CP. SL Control point P1, control point P2, and connection point CP AL By drawing cubic Bézier curves and using vehicles as the planning objects, the virtual path can be made dynamic through the variability of control points P1 and P2. This can also eliminate conflicts or reduce conflict areas, thereby improving traffic efficiency.

[0137] In a third aspect, the present application improves the applicability of the virtual path VP by determining the way of generating the virtual path VP according to the intersection condition, and obtaining the virtual path in different ways for different applicable situations, so that the virtual path generation is targeted and accurate.

[0138] In a fourth aspect, the present application considers the complexity of the Bezier curve calculation, and the existing planning system generally uses a special computer arranged at the intersection, and other computers with strong computing power are difficult to deploy, and the computing power of the special computer is not strong. Therefore, the present application realizes the virtual critical area VCA sequence based on the way of fitting the Bezier curve by the line segment, so that compared with the curve calculation, the calculation complexity can be reduced.

[0139] In a fifth aspect, the present application is based on the way of fitting the Bezier curve by the line segment in forming the virtual critical area, generates a temporary virtual critical area sequence in the first stage, further sets a safety distance for each temporary virtual critical area based on the temporary virtual critical area sequence, and generates a virtual critical area sequence. Therefore, the temporary virtual critical area sequence of the present application can plan a feasible path, and can accurately obtain the included angle between the leading edge and the trailing edge of two temporary virtual critical areas, accurately define the safety distance through the included angle, and more accurately avoid the gap between different temporary virtual critical areas.

[0140] In a sixth aspect, the temporary virtual critical area TVCA scheme of the present application generates a TVCA according to the position after the vehicle finds a parking position close to but without collision according to the ranging device or positioning, and releases other VCA after staying in the TVCA. That is, the present application divides the virtual critical area for the vehicle, and if the virtual critical area where the vehicle stops has an overlapping part with the virtual critical area of other vehicles, in order to avoid collision, other vehicles cannot drive according to the divided virtual critical area sequence, that is, other vehicles cannot pass through the virtual critical area with the overlapping part in the virtual critical area sequence of the vehicle itself, and in some cases, other vehicles should stop driving. Considering safety, other vehicles can stop at the previous virtual critical area of the virtual critical area with the overlapping part in the virtual critical area sequence, but this also leads to the virtual critical area with the overlapping part of the stopped other vehicle being empty. The present application allocates a temporary virtual critical area, and limits the temporary virtual critical area between the virtual critical area VCA3 and the virtual critical area VCA4, so as to avoid the virtual critical area VCA1 with the overlapping part, and release part of the VCA4 region, and reduce the empty space.

[0141] Based on the above embodiments, the present application further provides a computer program, which, when running on a computer, enables the computer to execute the method provided in the above embodiments.

[0142] Based on the above embodiments, the embodiments of the present application further provide a computer storage medium, which stores a computer program. The computer program is executed by a computer, so that the computer executes the method provided by the above embodiments.

[0143] The storage medium can be any available medium that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Computer-readable media can further include, but are not limited to, bus- based memory cores, program

[0144] Based on the above embodiments, the embodiments of the present application further provide a chip for reading a computer program stored in a memory, and implementing the method provided by the above embodiments.

[0145] Based on the above embodiments, the embodiments of the present application provide a computer program product. When the computer program product is run on an electronic device, the method provided by the above embodiments is implemented.

[0146] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage devices, etc.) containing computer-usable program code.

[0147] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, as well as a combination of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing apparatus to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing apparatus produce a device that implements the functions specified in the flowcharts and / or block diagrams. Figure 1 The functions specified in a flow or multiple flows and / or blocks Figure 1 The functions specified in a flow or multiple flows and / or blocks

[0148] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the flow Figure 1 The flow or flows and / or blocks Figure 1 The flow or flows and / or blocks

[0149] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions that execute on the computer or other programmable apparatus provide steps for implementing the flow Figure 1 The flow or flows and / or blocks Figure 1 The flow or flows and / or blocks

[0150] Obviously, numerous modifications and variations of the present application are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims and their equivalents, the application can be practiced otherwise than as specifically described.

Claims

1. A method of dynamic critical area division of an intersection, characterized by, comprising S100. obtaining a virtual path VP according to a start lane SL and a destination lane AL; S200. obtaining an actual path AP according to the virtual path VP; S300. obtaining a virtual critical area VCA sequence according to the actual path AP, the virtual critical area VCA sequence being an area that a vehicle needs to occupy when passing through an intersection; the method of obtaining the virtual critical area VCA sequence according to the actual path AP in the step S300, comprising S310. the connection point that constitutes the kth line segment of the actual path AP as the starting point of the initial virtual critical zone in the rear edge midpoint of the vehicle direction At this time, i = 1, k = 1; S320. Find the kth line segment constituting the actual path AP positive direction, destination lane center line upper and initial virtual critical region point in the rear edge midpoint in the vehicle direction point at a distance VL, if found, performing a step S330; if not found, increasing k by 1 and repeating the step S320; S330. generating an initial virtual critical zone with the point as an initial virtual critical zone a leading edge midpoint in the vehicle direction , generating an initial virtual critical zone according to the position of the leading edge midpoint in the vehicle direction a trailing edge midpoint in the vehicle direction and the leading edge midpoint in the vehicle direction , the initial virtual critical zone is a virtual critical zone with a safety distance , a virtual critical zone with a safety distance of 0; S340. Determine if the initial virtual critical zone has a leading edge midpoint in the vehicle direction that is on the destination lane centerline , if yes, the initial virtual critical area VCA sequence is generated, and a step S360 is performed; if no, a step S350 is performed; S350. the initial virtual critical zone the leading edge midpoint in the vehicle direction as the initial virtual critical zone the trailing edge midpoint in the vehicle direction i is incremented by 1, and step S320 is executed. S360. i = 1; S370. Calculate initial virtual critical zone of safety distance , generate virtual critical zone according to the safety distance ; S380. Determine if the initial virtual critical section is the last one ,​ if no, increasing i by 1 and performing a step S370; if yes, the virtual critical area VCA sequence is generated.

2. The method of claim 1, wherein, the method of obtaining the virtual path VP according to the start lane SL and the destination lane AL in the step S100, comprising S110. with the start lane centerline and the destination lane centerline whether the virtual path VP is generated in the same straight line If the starting lane centerline is determined and the center line of the destination lane If they are on the same straight line, generate the virtual path VP in the first way and execute step S120; If it is judged that the start lane center line and the destination lane center line are not on the same straight line, the virtual path VP is generated in the second way, and step S130 is executed. S120. generating the virtual path VP in a first way: starting with the lane center line of the origin connection point to the intersection , the lane center line of the destination connection point to the intersection , the connection line of the connection point to the connection point is the virtual path VP; S130. generating the virtual path VP in a second way: S131. Calculate control points and The coordinates of the control point It is the center line of the starting lane. The connection point on the extension line extending into the intersection Distance is The point, the control point The center line of the destination lane The connection point on the extension line extending into the intersection Distance is point; S132. drawing a cubic Bezier curve with the control points , the control points , the control points , and the connection points drawing a cubic Bezier curve with the control points 3. The method of claim 2, wherein, The actual path AP is a broken line formed by a plurality of line segments with both start points and end points on the virtual path VP or the center line of the target lane The length of each line segment is , and the driving direction of the vehicle is the positive direction of the virtual path VP and the actual path AP. represents the kth line segment of the actual path AP, represents the length of the kth line segment of the actual path AP , and k is a positive integer. the method of obtaining the actual path AP according to the virtual path VP in the step S200, comprising: S210. at the connection point as a starting point of the kth line segment of the actual path AP, where k = 1. S220. Calculate the length of the kth line segment constituting the actual path AP ;​ S230. Looking for a point in the virtual path VP positive direction which constitutes the kth line segment of the actual path AP The origin distance is the point, if the point exists, performing a step S240; if the point does not exist, performing a step S250; S240. Take the point mentioned in step S230 as the kth line segment constituting the actual path AP. The endpoint is the k-th line segment that constitutes the actual path AP. The endpoint is used as the (k+1)th line segment that constitutes the actual path AP. Starting from the beginning, increment k by 1 and execute step S220; S250. determining whether the origin of the kth line segment constituting the actual path AP coincides with the connection point S260. determining whether the end of the kth line segment constituting the actual path AP coincides with the connection point​ If we determine the kth line segment that constitutes the actual path AP The starting point and the connection point Overlapping, the actual path AP is from arrive The actual path AP has been generated; If it is judged that the start point of the kth line segment constituting the actual path AP does not coincide with the connection point , a point on the target lane center line which is a distance from the start point of the kth line segment constituting the actual path AP is sought as the end point of the kth line segment constituting the actual path AP , and the actual path AP is constituted by to , and the actual path AP is generated.

4. The method of claim 3, wherein, The virtual path VP is represented by the equation represents a cubic Bezier curve: wherein t is in the range [0, 1], denotes the connection point , denotes the control point , denotes the control point , denotes the connection point , and the position of the point is changed by adjusting the distance to the distance .

5. The method of claim 3, wherein, the kth line segment of the actual path AP length is represented by the following equation: is a positive floating point number, is a positive floating point number, is C(P) is the curvature of the virtual path VP at point P, and VL represents the vehicle length.

6. The method of claim 4, wherein, The i-th virtual critical zone generated in the positive direction of the actual path AP is represented as , i is a positive integer, the area occupied by the vehicle body is approximately a rectangle RA, the length VL of the rectangle RA represents the vehicle length, the width VW of the rectangle RA represents the vehicle width, and the rectangle RA is the initial virtual critical zone ; The initial virtual critical section The long VL increases the safe distance in front of the vehicle. The wide VW extends the safety distance on both sides of the vehicle. The resulting new rectangle is a virtual critical region. safe distance The safe distance is a positive number. The maximum value is half the difference between the lane width and the width (VW), and the safety distance is... Non-negative numbers, initial virtual critical section At the midpoint of the leading edge in the direction of the vehicle At the midpoint of the rear edge in the direction of the vehicle .

7. The method of claim 6, wherein, The safety distance is represented by the following equation: in, Initial virtual critical section Leading edge and initial virtual critical section The included angle of the trailing edge, the last initial virtual critical region safe distance It is 0.

8. The method of claim 6, wherein, the obstruction is in a first virtual critical area of a sequence of virtual critical areas VCA assigned to the first vehicle, a temporary virtual critical area is assigned to the first vehicle, the temporary virtual critical area does not contain the obstruction, occupies part of the first virtual critical area and a previous virtual critical area of the sequence of virtual critical areas VCA assigned to the first vehicle, and does not have overlap with virtual critical areas of sequences of virtual critical areas VCA assigned to other vehicles, a safety distance is added to the temporary virtual critical area if there is a gap between the temporary virtual critical area and the first virtual critical area a value of 0 if there is no gap between the temporary virtual critical area and the first virtual critical area ​ 9. The method of claim 8, wherein, The obstruction comprises a second vehicle, the virtual critical area VCA sequence assigned to the first vehicle has a partial overlap with one of the virtual critical area VCA sequences assigned to the second vehicle, the virtual critical area in the virtual critical area VCA sequence of the first vehicle having the overlap is a first virtual critical area, the virtual critical area in the virtual critical area sequence of the second vehicle having the overlap is a second virtual critical area, if the second vehicle is parked in the second virtual critical area, a temporary virtual critical area is assigned to the first vehicle for it to be parked completely within the temporary virtual critical area, the temporary virtual critical area occupies part of the first virtual critical area and a previous virtual critical area of the first virtual critical area, but does not overlap with the second virtual critical area, if there is a gap between the temporary virtual critical area and the first critical area, a corresponding safety distance is added to the temporary virtual critical area to fill the gap, if there is no gap between the temporary virtual critical area and the first critical area, the safety distance has a value of 0.

10. An electronic device, comprising: one or more processors, a memory, and one or more programs; wherein the one or more programs are stored in the memory and comprise instructions which, when executed by the electronic device, cause the electronic device to perform any one of the methods of claims 1-9.

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