CN107990905B

CN107990905B - Method and device for determining U-turn intersection

Info

Publication number: CN107990905B
Application number: CN201610958202.6A
Authority: CN
Inventors: 王芳
Original assignee: Autonavi Software Co Ltd
Current assignee: Alibaba China Co Ltd
Priority date: 2016-10-27
Filing date: 2016-10-27
Publication date: 2020-04-10
Anticipated expiration: 2036-10-27
Also published as: CN107990905A

Abstract

The application discloses a method and a device for determining a U-turn intersection. In the technical scheme provided by the application, compared with the prior art, the position of the U-turn intersection on the road is determined by extracting the turning point of the track of the user in the navigation process and calculating instead of acquiring information such as images and positions through field investigation and combining with traffic rules, so that a large amount of manpower and material resources are saved.

Description

Method and device for determining U-turn intersection

Technical Field

The application relates to the technical field of data mining, in particular to a method and a device for determining a turning intersection.

Background

With the continuous development and improvement of the traffic network, the traffic network is more and more huge, and people do not need to spend excessive energy to be familiar with the traffic network but use a map navigation service to travel based on a navigation route provided by the traffic network due to the rapid development of a software technology.

A u-turn intersection in a traffic network is indispensable information for a map navigation service as a position allowing a vehicle to turn around. In the prior art, a general method for determining a u-turn intersection is as follows: and manually collecting the turning intersection on the spot through professional equipment. However, the existing traffic network changes very frequently, and only manually collecting the u-turn intersection not only has the problem that the u-turn intersection can not be collected in time, but also has the problem that the cost of manpower and material resources is too high.

Disclosure of Invention

The embodiment of the application provides a method and a device for determining a U-turn intersection, which are used for solving the problems that manpower and material resources are wasted and the collection efficiency of the U-turn intersection is low by manually collecting through professional equipment in the prior art.

On one hand, the embodiment of the application provides a method for determining a u-turn intersection, which includes:

acquiring a yaw track record, wherein more than two track points sequenced in time sequence are recorded in the yaw track record;

acquiring the linear distance from other track points to the track point sequenced at the head;

traversing the linear distance of the trace points according to the sequencing sequence of the trace points, and acquiring the trace points of which the linear distance reaches an extreme value as target trace points;

and screening out target track points meeting the U-turn intersection rule from the target track points as U-turn intersection position points.

On the other hand, the embodiment of the present application provides a method for determining a u-turn intersection, including:

segmenting the more than two track points sequenced according to the time sequence;

the following operations are performed for each segment:

acquiring the linear distance from other track points in the segment to the track point serving as the starting point of the segment;

traversing the linear distance of the track points in the segment, and acquiring the track points of which the linear distance reaches an extreme value as target track points;

and screening out the target track points meeting the U-turn intersection rule in the segmentation as U-turn intersection position points from the target track points.

On the other hand, an embodiment of the present application provides a device for determining a u-turn intersection, including:

the first yaw track record acquisition module is used for acquiring a yaw track record, and the yaw track record records more than two track points sequenced according to time sequence;

the first straight-line distance acquisition module is used for acquiring straight-line distances from other track points to the track points sequenced at the head;

the first traversal module is used for traversing the linear distances of the track points according to the sequencing sequence of the track points and acquiring the track points of which the linear distances reach an extreme value as target track points;

and the first U-turn intersection determining module is used for screening out target track points meeting the U-turn intersection rule from the target track points as U-turn intersection position points.

the second yawing track record obtaining module is used for obtaining a yawing track record, and the yawing track record records more than two track points sequenced according to time sequence;

the segmentation module is used for segmenting the more than two track points sequenced according to the time sequence;

the second straight-line distance acquisition module is used for acquiring the straight-line distance from other track points in the segment to the track point serving as the segment starting point in the segment aiming at each segment;

the second traversal module is used for traversing the linear distance of the track points in each segment to obtain the track point of which the linear distance reaches an extreme value as a target track point;

and the second U-turn intersection determining module is used for screening out target track points which meet the U-turn intersection rule in the segmentation from the target track points as U-turn intersection position points.

The beneficial effect of this application is as follows: in the technical scheme provided by the embodiment of the application, as one yaw track record is obtained, more than two track points sequenced according to time sequence are recorded in the yaw track record; acquiring the linear distance from other track points to the track point sequenced at the head; traversing the linear distance of the trace points according to the sequencing sequence of the trace points, and acquiring the trace points of which the linear distance reaches an extreme value as target trace points; and screening out target track points meeting the U-turn intersection rule from the target track points as U-turn intersection position points. Therefore, the method and the device realize automatic determination of the position of the U-turn intersection based on the data mining technology, and do not need to manually survey and collect the information of the position of the U-turn intersection on the spot through professional equipment. Thereby achieving the purpose of saving manpower and material resources. Meanwhile, the position of the U-turn intersection is automatically excavated, and the determining speed of the position of the U-turn intersection can be improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic flow chart illustrating a method for determining a u-turn intersection according to an embodiment of the present application;

FIG. 2 is a first schematic diagram of a yaw trajectory record provided in an embodiment of the present application;

fig. 3 is a schematic diagram illustrating a variation trend of a straight line distance with a track point according to an embodiment of the present application;

FIG. 4 is a second schematic diagram of a yaw trajectory record provided in the first embodiment of the present application;

FIG. 5 is a schematic diagram illustrating a yaw trajectory record of a curved road segment according to an embodiment of the present application;

FIG. 6 is a schematic view of an included angle provided in an embodiment of the present application;

FIG. 7 is a schematic view of a linear distance diagram including serrations according to an embodiment of the present application;

FIG. 8 is a flow chart of averaging according to an embodiment of the present application;

FIG. 9 is a first schematic diagram illustrating a linear distance and a track distance according to a first embodiment of the present disclosure;

fig. 10 is a schematic diagram of a linear distance and a track distance according to a first embodiment of the present application;

fig. 11 is a schematic flow chart illustrating a method for determining a u-turn intersection according to a second embodiment of the present application;

fig. 12 is a schematic sectional view of a second embodiment of the present invention;

fig. 13 is a schematic sectional view of a second embodiment of the present invention;

fig. 14 is a schematic flow chart illustrating a method for determining a u-turn intersection according to a third embodiment of the present application;

fig. 15 is a schematic structural diagram of a u-turn intersection determination device according to a fourth embodiment of the present application;

fig. 16 is a schematic structural diagram of a u-turn intersection determination device according to a fifth embodiment of the present application;

fig. 17 is a schematic hardware structure diagram of an electronic device that executes a method for determining a u-turn intersection according to a seventh embodiment of the present application.

Detailed Description

After deviating from the navigation route, the navigation user often selects a proper position to turn around and returns to the navigation route again. The navigation terminal generates a yaw track record after determining that the user deviates from the navigation route. The yaw track record records more than two track points sequenced according to time sequence, and is used for describing a section of user track after the user deviates from the navigation route. For example, the yaw trajectory record may record the user trajectory within a preset time period from the start of the user's deviation from the navigation route, or the user trajectory within a preset trajectory distance from the start of the user's deviation from the navigation route. In general, after deviating from the navigation route, the user is used to turn around and return to the navigation route again, so the yaw trajectory record necessarily includes the position where the user turns around, i.e., the position of the turn-around intersection.

Based on the principle, the embodiment of the application provides a method and a device for determining a U-turn intersection. In the technical scheme provided by the embodiment of the application, as one yaw track record is obtained, more than two track points sequenced according to time sequence are recorded in the yaw track record; acquiring the linear distance from other track points to the track point sequenced at the head; traversing the linear distance of the trace points according to the sequencing sequence of the trace points, and acquiring the trace points of which the linear distance reaches an extreme value as target trace points; and screening out target track points meeting the U-turn intersection rule from the target track points as U-turn intersection position points. Therefore, the automatic determination of the turning intersection position based on the data mining technology is realized. Therefore, the information of the turn-around intersection position is investigated and collected on the spot without manually passing through professional equipment, and the purpose of saving manpower and material resources is achieved. Meanwhile, the position of the U-turn intersection is automatically excavated, and the determining speed of the position of the U-turn intersection can be improved.

In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be described in further detail with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The first embodiment is as follows:

as shown in fig. 1, a schematic flow chart of a method for determining a u-turn intersection provided in the embodiment of the present application is shown, where the method includes the following steps:

step 101: and acquiring a yaw track record, wherein more than two track points sequenced according to time sequence are recorded in the yaw track record.

In one embodiment, after a user deviates from a navigation route, a navigation terminal generates a yaw log in which a track point sequence for representing a yaw track record is recorded. In particular embodiments, a yaw trajectory record may be obtained from the yaw log. Of course, the yaw trajectory record may also be determined according to the prior art, which is not limited in the embodiment of the present application.

It should be further noted that the execution subject in the embodiment of the present application may be a navigation terminal or a navigation server. In specific implementation, the determination can be made according to actual needs, and the application does not limit the determination.

Step 102: and acquiring the linear distance from other track points to the track point sequenced at the head.

As shown in fig. 2, a schematic diagram of a yaw trajectory record is shown, where point a is a trajectory point sorted at the head and point E is a trajectory point sorted at the end. And the point B, the point C and the point D are track points positioned between the point A and the point E in the yaw track record. L1 is the straight-line distance between point C and point a (i.e., trace point C to trace point a ordered at the top).

Step 103: and traversing the linear distance of the trace points according to the sequencing sequence of the trace points, and acquiring the trace points of which the linear distance reaches an extreme value as target trace points.

Wherein the extreme value may be at least one of a maximum value and a minimum value.

Wherein, the target track point contains the turning intersection position point. Here, for convenience of understanding, the principle that the trace point at which the linear distance reaches the extreme value is taken as the target trace point in the embodiment of the present application is explained, which includes the following two parts, that is, the description that the trace point at which the linear distance reaches the maximum value is taken as the target trace point, and that the trace point at which the linear distance reaches the minimum value is taken as the target trace point.

1. Explanation of the principle of using the maximum value point as the target track point:

continuing with the example shown in FIG. 2, point C is the U-turn intersection location point; before the vehicle turns around, namely before the vehicle drives from the point A to the point C, the linear distance from the track point to the track point A sequenced at the head gradually increases; after turning around, the straight line distance is gradually reduced, so that the straight line distance is the maximum value at the turning around intersection position point. The trend of the straight-line distance with the track point calculated from the yaw-track recording of fig. 2 can be represented by fig. 3. Before the point O (i.e., the maximum point), the linear distance is continuously increased, and after the point O, the linear distance is continuously decreased, so the point O corresponds to the point C in fig. 2, and the trace point corresponding to the maximum point such as the point O is used as the target trace point.

2. Explanation of the principle of the minimum point as the target trace point:

as shown in fig. 4, point F is another turning intersection position point, the straight-line distance of the vehicle gradually decreases before turning around, and the straight-line distance gradually increases after turning around. Based on the similar reason, the track point corresponding to the minimum value point can be used as the target track point.

Step 104: and screening out target track points meeting the U-turn intersection rule from the target track points as U-turn intersection position points.

For convenience of understanding, the following further description of the method for determining a u-turn intersection provided in the embodiments of the present application may include the following:

in one embodiment, some roads are curved in nature, and a curved road segment may include exactly one target track point. Such target track points cannot be used as turning intersection position points. Taking fig. 5 as an example, the yaw trajectory records MN is a curved road segment (which can be regarded as a roundabout road segment), M is a track point ordered at the head, and N is a track point ordered at the end. And traversing the linear distance of the track points according to the sequencing sequence of the track points, wherein the point Q is the track point of which the linear distance reaches an extreme value, but the point Q does not meet the turning intersection rule. Therefore, a target track point such as the Q point cannot be used as a u-turn intersection position point. In this embodiment of the application, in order to make the determined u-turn intersection position point more accurate, step 104 (i.e., screening out the target track points satisfying the u-turn intersection rule as the u-turn intersection position points) may execute the following operations for each target track point:

step A1: and respectively acquiring a track point with the minimum difference between the linear distance to the target track point and a preset linear distance threshold value from the track points sequenced before and after the target track point.

Step A2: and calculating the value of an included angle formed by the two obtained track points and the target track point by taking the target track point as an angular vertex.

Continuing with the example of fig. 2, as shown in fig. 6, point C is the target track point, point B is the track point with the smallest difference between the linear distance to point C sorted before point C and the preset linear distance threshold, point D is the track point with the smallest difference between the linear distance to point C sorted after point C and the preset linear distance threshold, point ∠ m is the angle formed by point C and point B and point D, and the angle is an angle smaller than 180 °.

Step A3: and judging whether the value of the included angle meets the preset included angle value range of the U-turn intersection, and if so, regarding the target track point as the position point of the U-turn intersection.

In practice, the traveling directions of the vehicles are opposite and approach to 180 degrees before and after the U-turn intersection. As such, the included angle determined according to step a2 at the u-turn intersection location is approximately 0 °. Therefore, in specific implementation, the range of the angle value of the preset u-turn intersection is, for example, a range composed of a smaller angle, for example, 1 ° to 10 °, and in specific implementation, the angle value can be set according to actual needs, which is not limited in the embodiment of the present application.

Therefore, according to the characteristic of the included angle at the position of the U-turn intersection, the target track point meeting the rule of the U-turn intersection is screened out to be used as the position point of the U-turn intersection, so that the determined position point of the U-turn intersection is more accurate.

In one embodiment, the driving track of the vehicle is an uneven curve because the acquired track points are not very accurate. In addition, the road itself may be curved, and so on, which may cause the straight distance to fluctuate before and after the u-turn intersection. As shown in fig. 7, the straight distance has a sawtooth-like fluctuation. Therefore, in the embodiment of the present application, in order to make the determined turn-around intersection location point more accurate, before step 103 (i.e., traversing the straight-line distances of the trace points in the sorting order of the trace points), as shown in fig. 8, the following steps are performed:

step B1: and obtaining the mean value of the linear distances of the ith, the (i + 1) th and the (i + 2) th track points, and taking the mean value as the linear distance used for traversing the (i + 1) th track point.

For example, the method comprises the following steps:

wherein, f (i) is the straight line distance of the ith track point, and so on.

The mean value of the straight-line distances of the ith, the (i + 1) th and the (i + 2) th track points is obtained.

Step B2: and judging whether the (i + 2) th track point is the last track point in the yaw track record, if not, determining that i is i +1, returning to the step of obtaining the mean value of the linear distances of the (i) th, the (i + 1) th and the (i + 2) th track points, wherein the initial value of i is any natural number.

By the method of averaging, the curve can be smooth, invalid target track points are filtered, and the determined turning intersection position points are more accurate.

In one embodiment, in order to prevent the determined u-turn intersection position point from being repeated, before step 104 (i.e. screening out the target track point satisfying the u-turn intersection rule as the u-turn intersection position point), the following steps may be performed:

step C1: and obtaining the track distance between two adjacent target track points in the target track points.

Step C2: and judging whether the track distance is smaller than a set track distance threshold value, if so, deleting any one of the two target track points.

Wherein in one embodiment the change in the linear distance is slow at curved road sections. And the track distance from the track point to the track point sequenced at the head is continuously increased, and the increase amplitude is larger than the change amplitude of the straight-line distance. As shown in fig. 9, for a curved road segment at a non-u-turn intersection, the straight-line distance corresponding to each track point is not greater than the track distance. Before the target track point (i.e., point P in fig. 9) of the curved road segment, the straight-line distance corresponding to the track point is smaller than the track distance. At the u-turn intersection, as shown in fig. 10, the straight-line distance is substantially the same as the track distance before the R point (i.e., the target track point). Based on the difference between the u-turn intersection and the curved road segment, the embodiment of the present application may perform the following steps before step 104 (i.e., screening out the target track point satisfying the u-turn intersection rule as the u-turn intersection position point):

step D1: and acquiring the track distance from the target track point to the track point sequenced at the head.

Step D2: and calculating the difference value between the linear distance and the track distance of the target track point, and deleting the target track point if the difference value is greater than the preset distance difference value.

Therefore, the extreme point in the curved road section of the non-U-turn intersection is equivalently eliminated, so that the finally obtained U-turn intersection position point is more accurate.

In the specific implementation, the steps a1-A3, C1-C2 and D1-D2 can be executed before the step 104, and the execution sequence is not limited; the method may also be implemented as three embodiments of step 104, which is not limited in this application.

In summary, in the method for determining a u-turn intersection provided in the embodiment of the present application, a yaw trajectory record is obtained, where the yaw trajectory record records more than two trajectory points sequenced in time sequence; acquiring the linear distance from other track points to the track point sequenced at the head; traversing the linear distance of the trace points according to the sequencing sequence of the trace points, and acquiring the trace points of which the linear distance reaches an extreme value as target trace points; and screening out target track points meeting the U-turn intersection rule from the target track points as U-turn intersection position points. Therefore, the method and the device realize automatic determination of the position of the U-turn intersection based on the data mining technology, and do not need to manually survey and collect the information of the position of the U-turn intersection on the spot through professional equipment. Thereby achieving the purpose of saving manpower and material resources. Meanwhile, the position of the U-turn intersection is automatically excavated, and the determining speed of the position of the U-turn intersection can be improved.

Example two:

as shown in fig. 11, a schematic flow chart of a method for determining a u-turn intersection provided in the embodiment of the present application includes the following steps:

step 1101: and acquiring a yaw track record, wherein more than two track points sequenced according to time sequence are recorded in the yaw track record.

Step 1102: and segmenting the more than two track points sequenced according to the time sequence.

Because there are multiple intercommunicating routes between cities and between different urban areas in the cities, there are multiple intercommunicating routes even between different points of interest. Therefore, the number of yaw trajectory records is very large, resulting in a large amount of data required to determine the turn-around intersection position. In the embodiment of the application, in order to improve the speed of determining the position of the U-turn intersection, the track points sequenced by more than two time sequences can be segmented.

Step 1103: and acquiring the straight-line distance from other track points in each segment to the track point serving as the starting point of the segment in the segment.

Step 1104: and traversing the linear distance of the track points in the segment, and acquiring the track point of which the linear distance reaches an extreme value as a target track point.

Step 1105: and screening out the target track points meeting the U-turn intersection rule in the segmentation as U-turn intersection position points from the target track points.

in one embodiment, in order to implement reasonable segmentation, step 1102 (i.e. segmenting the two or more track points ordered in chronological order) may be implemented as the following steps:

step E1: and acquiring the track points serving as the segmentation starting points from the more than two track points sequenced in time sequence.

Step E2: and acquiring the track distance from the track point sequenced after the starting point of the segment to the starting point of the segment.

Step E3: and if the currently acquired track distance reaches a preset segmentation track distance threshold value, dividing the track point which is taken as the segmentation starting point, the track point of which the track distance reaches the preset segmentation track distance threshold value and the track points between the track points into one section.

In specific implementation, a preset number of track points can be divided into a group, and a road section corresponding to each group of track points is a subsection; alternatively, the segmentation may be performed according to a linear distance, in addition to the above-described trajectory distance segmentation. The method comprises the steps of obtaining the linear distance from a track point sequenced after a segmentation starting point to the segmentation starting point, and dividing the track point as the segmentation starting point to the track point with the linear distance reaching the preset segmentation linear distance threshold value and the track points between the track point and the track point into a section if the currently obtained linear distance reaches the preset segmentation linear distance threshold value.

In one embodiment, when the track points are processed in a segmented manner, the turn-around intersection position point may be right at the joint of two adjacent track segments, so that the turn-around intersection position point is omitted when data is processed. Taking fig. 12 as an example, fig. 12 shows (1) one segment and (2) another segment. And the point C is a U-turn intersection position point and is positioned at the joint of the two sections (1) and (2). Thus, when step 1104 (a trace point at which the straight line distance reaches the extreme value is acquired as a target trace point), point C is left out.

Therefore, in the embodiment of the present application, in order to not omit the u-turn intersection location point, the step E1 may specifically perform the following steps:

step F1: and for the first segment, determining the track point at the head position in the more than two track points sequenced according to the time sequence as the segment starting point.

Step F2: and for the segments after the first segment, calculating the track distance from the track point in the previous segment of the current segment to the starting point of the previous segment, and acquiring the track point with the minimum difference between the track distance and a preset track distance threshold of the starting point of the segment as the starting point of the segment of the current segment.

In specific implementation, for a segment after the first segment, the track distance from the track point in the previous segment of the current segment to the end point of the previous segment may be calculated, and the track point with the minimum difference between the track distance and the preset segment end point track distance threshold is obtained as the segment start point of the current segment.

In this way, a partial overlap between adjacent segments can be achieved. Taking fig. 13 as an example, there is a partial overlap between the segment (3) and the segment (4), and the u-turn intersection position point C is on the overlapping portion of the segment (3) and the segment (4). Because the adjacent track segments are partially overlapped during the segmentation, when the target track point is obtained in the step 1104, the point C, that is, the turning intersection position point, is not missed.

In one embodiment, for similar reasons as those in the first embodiment of the present application, which is performed in steps B1-B2, the following steps are performed before step 1104 (i.e., traversing the straight-line distance of the trace point in the segment) in the first embodiment of the present application:

step G1: and obtaining the mean value of the linear distances of the ith, ith +1 and ith +2 track points in the segment, and taking the mean value as the linear distance used for traversing the ith +1 track point.

Step G2: and judging whether the (i + 2) th track point is the last track point in the segment, if not, determining that i is i +1, returning to the step of obtaining the mean value of the linear distances of the (i + 1) th, i + 2) th track points in the segment, wherein the initial value of i is any natural number.

In one embodiment, due to the partial overlapping between the adjacent track segments, the u-turn intersection position point at the overlapped part is repeatedly calculated, so that the finally obtained u-turn intersection position point is repeated. Taking fig. 13 as an example, the u-turn intersection position point C is determined once in the track segment (3) and once in the track segment (4). In view of this, in the embodiment of the present application, before step 1105 (that is, screening out the target track point satisfying the u-turn intersection rule in the segment as the u-turn intersection position point), the repeated u-turn intersection position point may be eliminated by the following steps:

step H1: and obtaining the track distance between two adjacent target track points in the target track points.

Step H2: and judging whether the track distance is smaller than a set track distance threshold value, if so, deleting any one of the two target track points from the target track points.

Thus, by eliminating repeated target track points, repeated turning intersection position points are eliminated.

In one embodiment, for reasons similar to the reason for executing steps D1-D2 in the first embodiment of the present application, the first embodiment of the present application executes step N1 before step 1105 (i.e., filters out the target track point satisfying the u-turn intersection rule in the segment as the u-turn intersection location point): and acquiring a difference value between a linear distance from the target track point to the starting point of the segment to which the target track point belongs and the track distance, and deleting the target track point if the difference value is greater than a preset distance difference value.

In one embodiment, for reasons similar to the execution of a1-A3 in the first embodiment of the present application, in the present embodiment of the present application, step 1105 (i.e., filtering out the target track point satisfying the u-turn intersection rule in the segment as the u-turn intersection position point) may perform the following operations for each target track point:

step I1: and respectively acquiring a track point with the minimum difference between the linear distance to the target track point and a preset linear distance threshold value from track points which are sequenced in front of and behind the target track point in the yaw track record.

Step I2: and calculating the value of an included angle formed by the two obtained track points and the target track point by taking the target track point as an angular vertex.

Step I3: and judging whether the value of the included angle meets the preset included angle condition of the U-turn intersection, and if so, regarding the target track point as the position point of the U-turn intersection.

Therefore, according to the characteristic of the included angle at the position point of the U-turn intersection, the target track point meeting the rule of the U-turn intersection is screened out to be used as the position point of the U-turn intersection, so that the determined position of the U-turn intersection is more accurate.

Therefore, the finally obtained turning intersection position point is more accurate.

It should be noted that, in the specific implementation, steps H1-H2, steps I1-I3, and step N1 may be performed before step 1105, and the execution order is not limited; the method may be implemented as three embodiments of step 1105, which is not limited in this application.

In summary, in the technical solution provided in the embodiment of the present application, a yaw trajectory record is obtained, where the yaw trajectory record records more than two trajectory points ordered in time sequence; segmenting the more than two track points sequenced according to the time sequence; for each segment, acquiring the linear distance from other track points in the segment to the track point serving as the starting point of the segment in the segment; traversing the linear distance of the track points in the segment, and acquiring the track points of which the linear distance reaches an extreme value as target track points; and screening out the target track points meeting the U-turn intersection rule in the segmentation as U-turn intersection position points from the target track points. Therefore, the method and the device realize automatic determination of the position of the U-turn intersection based on the data mining technology, and do not need to manually survey and collect the information of the position of the U-turn intersection on the spot through professional equipment. Thereby achieving the purpose of saving manpower and material resources. Meanwhile, the position of the U-turn intersection is automatically excavated, and the determining speed of the position of the U-turn intersection can be improved.

EXAMPLE III

For convenience of understanding, the method for determining a u-turn intersection provided in the embodiment of the present application is further described, as shown in fig. 14, which is a schematic flow chart of the method, and includes the following steps:

step 1401: and acquiring a yaw track record, wherein more than two track points sequenced according to time sequence are recorded in the yaw track record.

Step 1402: and segmenting the more than two track points sequenced according to the time sequence.

Step 1403: and for each segment, acquiring the straight-line distance from other track points in the segment to the track point serving as the segment starting point in the segment.

Step 1404: and obtaining the mean value of the linear distances of the ith, ith +1 and ith +2 track points in the segment, and taking the mean value as the linear distance used for traversing the ith +1 track point.

Step 1405: judging whether the (i + 2) th track point is the last track point in the segment, if not, executing a step 1406; if yes, go to step 1407.

Step 1406: i +1 and returns to step 1404.

Step 1407: and traversing the linear distance of the track points in the segment, and acquiring the track point of which the linear distance reaches an extreme value as a target track point.

Step 1408: and obtaining the track distance between two adjacent target track points in the target track points.

Step 1409: judging whether the track distance is smaller than a set track distance threshold value, if so, executing a step 1410; if not, go to step 1411.

Step 1410: and deleting any one of the two target track points from the target track points.

Step 1411: and acquiring the difference value between the linear distance from the target track point to the starting point of the segment to which the target track point belongs and the track distance.

Step 1412: judging whether the difference is larger than a preset distance difference, if so, executing a step 1413; if not, go to step 1414.

Step 1413: and deleting the target track point.

Step 1414: and aiming at each target track point, sequencing track points before and after the target track point from the yaw track record, and respectively acquiring a track point with the minimum difference between the linear distance to the target track point and a preset linear distance threshold value.

Step 1415: and calculating the value of an included angle formed by the two obtained track points and the target track point by taking the target track point as an angular vertex.

Step 1416: judging whether the value of the included angle meets a preset included angle condition of the U-turn intersection, if so, executing a step 1417; if not, the process is ended.

Step 1417: and regarding the target track point as a turning intersection position point.

In summary, in the method provided in the embodiment of the present application, a yaw trajectory record is obtained, where the yaw trajectory record records more than two trajectory points ordered in time sequence; segmenting the more than two track points sequenced according to the time sequence; for each segment, acquiring the linear distance from other track points in the segment to the track point serving as the starting point of the segment in the segment; traversing the linear distance of the track points in the segment, and acquiring the track points of which the linear distance reaches an extreme value as target track points; and screening out the target track points meeting the U-turn intersection rule in the segmentation as U-turn intersection position points from the target track points. Therefore, the method and the device realize automatic determination of the position of the U-turn intersection based on the data mining technology, and do not need to manually survey and collect the information of the position of the U-turn intersection on the spot through professional equipment. Thereby achieving the purpose of saving manpower and material resources. Meanwhile, the position of the U-turn intersection is automatically excavated, and the determining speed of the position of the U-turn intersection can be improved.

Example four:

based on the same inventive concept, the embodiment of the present application further provides a u-turn intersection determination device, and the determination principle of the u-turn intersection of the device is similar to that of the u-turn intersection determination method in the first embodiment. For details, reference may be made to the contents of the above-mentioned methods, which are not described herein in detail.

As shown in fig. 15, which is a schematic structural diagram of the apparatus, the apparatus includes:

a first yaw trajectory record obtaining module 1501, configured to obtain a yaw trajectory record, where the yaw trajectory record records more than two trajectory points sorted in time sequence;

a first straight-line distance obtaining module 1502, configured to obtain straight-line distances from other track points to the track point ordered at the head;

the first traversal module 1503 is used for traversing the linear distances of the track points according to the sequencing order of the track points, and acquiring the track points of which the linear distances reach an extreme value as target track points;

and a first u-turn intersection determining module 1504, configured to screen out, from the target track points, a target track point that meets a u-turn intersection rule as a u-turn intersection position point.

In one embodiment, the first u-turn intersection determining module includes:

the first track point acquisition unit is used for respectively acquiring a track point with the minimum difference between the linear distance to the target track point and a preset linear distance threshold from track points sequenced before and after the target track point aiming at each target track point;

the first included angle calculating unit is used for calculating the value of an included angle formed by the two acquired track points and each target track point by taking the target track point as an angular vertex for each target track point;

and the first included angle judging unit is used for judging whether the included angle value meets the preset included angle value range of the U-turn intersection or not, and if so, the target track point is regarded as the position point of the U-turn intersection.

Wherein, in one embodiment, the apparatus further comprises:

the first mean value acquisition module is used for acquiring the mean values of the straight line distances of the ith, the (i + 1) th and the (i + 2) th track points before the first traversal module traverses the straight line distances of the track points, and taking the mean values as the straight line distances of the (i + 1) th track points for traversal;

and the first judgment module is used for judging whether the (i + 2) th track point is the last track point in the yaw track record, if not, i is equal to i +1, the step of obtaining the mean value of the linear distances of the (i + 1) th, i + 2) th track points is returned, and the initial value of i is any natural number.

Wherein, in one embodiment, the apparatus further comprises:

the first track distance acquisition module is used for acquiring the track distance between two adjacent target track points in the target track points before the target track points meeting the turn-around intersection rule are screened out by the first turn-around intersection determination module to serve as turn-around intersection position points;

and the second judgment module is used for judging whether the track distance is smaller than a set track distance threshold value, and if so, deleting any one of the two target track points.

Wherein, in one embodiment, the apparatus further comprises:

the second track distance acquisition module is used for acquiring the track distance from the target track point to the track point sequenced at the head before the first U-turn intersection determination module screens out the target track point meeting the U-turn intersection rule in the segment as the U-turn intersection position point;

and the difference value calculating module is used for calculating the difference value between the linear distance and the track distance of the target track point, and deleting the target track point if the difference value is greater than the preset distance difference value.

In summary, in the device for determining a u-turn intersection provided in the embodiment of the present application, the first yaw trajectory record obtaining module obtains one yaw trajectory record; the first linear distance acquisition module acquires linear distances from other track points to the track points sequenced at the head; the first traversal module traverses the straight-line distances of the track points according to the sequencing sequence of the track points, and obtains the track points of which the straight-line distances reach an extreme value as target track points; and the first U-turn intersection determining module screens out target track points meeting the U-turn intersection rule from the target track points as U-turn intersection position points. Therefore, the method and the device realize automatic determination of the position of the U-turn intersection based on the data mining technology, and do not need to manually survey and collect the information of the position of the U-turn intersection on the spot through professional equipment. Thereby achieving the purpose of saving manpower and material resources. Meanwhile, the position of the U-turn intersection is automatically excavated, and the determining speed of the position of the U-turn intersection can be improved.

Example five:

based on the same inventive concept, the embodiment of the application also provides a device for determining the u-turn intersection, and the determination principle of the u-turn intersection of the device is similar to that of the method for determining the u-turn intersection in the second embodiment. For details, reference may be made to the contents of the above-mentioned methods, which are not described herein in detail.

As shown in fig. 16, which is a schematic structural diagram of the apparatus, the apparatus includes:

a second yaw trajectory record obtaining module 1601, configured to obtain a yaw trajectory record, where the yaw trajectory record records more than two trajectory points ordered in time sequence;

a segmenting module 1602, configured to segment the more than two track points ordered according to the chronological order;

a second straight-line distance obtaining module 1603, configured to, for each segment, obtain straight-line distances from other track points in the segment to a track point serving as a segment start point in the segment;

the second traversal module 1604 is configured to traverse, for each segment, the linear distance of the trace point in the segment, and obtain a trace point of which the linear distance reaches an extreme value as a target trace point;

and a second u-turn intersection determining module 1605, configured to screen out, from the target track points, a target track point that meets the u-turn intersection rule in the segment as a u-turn intersection position point.

Wherein, in one embodiment, the segmentation module 1602 includes:

the track point determining unit is used for acquiring track points serving as segmentation starting points from the more than two track points sequenced in time sequence;

a track distance obtaining unit, configured to obtain a track distance from a track point ordered after a segment start point to the segment start point;

and the track segment determining unit is used for dividing the track point serving as the segmentation starting point to the track point of which the track distance reaches the preset segmentation track distance threshold value and the track points between the track points into one segment if the currently acquired track distance reaches the preset segmentation track distance threshold value.

In one embodiment, the track point determination unit that the segments are sorted at the top includes:

the track point determining subunit is used for determining the track point at the head of the more than two track points sequenced according to the time sequence as the starting point of the first segment;

and the track point determining subunit is used for calculating the track distance from the track point in the previous segment of the current segment to the starting point of the previous segment for the segments after the first segment, and acquiring the track point with the minimum difference between the track distance and a preset segment starting point track distance threshold as the segment starting point of the current segment.

Wherein, in one embodiment, the apparatus further comprises:

the second mean value acquisition module is used for acquiring the mean value of the straight line distances of the ith, the (i + 1) th and the (i + 2) th track points in the segment before the second traversal module traverses the straight line distances of the track points in the segment, and taking the mean value as the straight line distance for traversing the (i + 1) th track point;

and the third judging module is used for judging whether the (i + 2) th track point is the last track point in the segment, if not, the i is equal to i +1, the step of obtaining the mean value of the straight-line distances of the (i + 1) th, i + 2) th track points in the segment is returned, and the initial value of the i is any natural number.

Wherein, in one embodiment, the apparatus further comprises:

a third track distance acquisition module, configured to acquire a track distance between two adjacent target track points in the target track points before the second u-turn intersection determination module selects, as u-turn intersection position points, target track points that satisfy u-turn intersection rules in the segment;

and the fourth judging module is used for judging whether the track distance is smaller than a set track distance threshold value, and if so, deleting any one of the two target track points from the target track points. Wherein, in one embodiment, the apparatus further comprises:

and the difference value acquisition module is used for acquiring the difference value between the linear distance from the target track point to the segment starting point of the segment to which the target track point belongs and the track distance before the second U-turn intersection determination module screens out the target track point meeting the U-turn intersection rule in the segment as the U-turn intersection position point, and deleting the target track point if the difference value is greater than the preset distance difference value.

Wherein, in one embodiment, the second u-turn intersection determining module 1605 includes:

the second track point acquisition unit is used for sequencing track points before and after each target track point from the yaw track record aiming at each target track point, and respectively acquiring a track point with the minimum difference between the linear distance to the target track point and a preset linear distance threshold value;

the second included angle calculating unit is used for calculating the value of an included angle formed by the two acquired track points and the target track point by taking the target track point as an angular vertex;

and the second included angle judging unit is used for judging whether the included angle value meets the preset included angle condition of the U-turn intersection or not, and if so, the target track point is regarded as the position point of the U-turn intersection.

In summary, in the u-turn intersection determining device provided in the embodiment of the present application, the second yaw trajectory record obtaining module obtains one yaw trajectory record; the segmentation module segments the more than two track points sequenced according to the time sequence; the second straight-line distance acquisition module acquires the straight-line distance from other track points in the segment to the track point serving as the segment starting point in the segment aiming at each segment; the second traversal module traverses the straight-line distance of the track points in the segment, and obtains the track points of which the straight-line distance reaches an extreme value as target track points; and the second U-turn intersection determining module screens out the target track points meeting the U-turn intersection rule in the segmentation from the target track points as U-turn intersection position points. Therefore, the method and the device realize automatic determination of the position of the U-turn intersection based on the data mining technology, and do not need to manually survey and collect the information of the position of the U-turn intersection on the spot through professional equipment. Thereby achieving the purpose of saving manpower and material resources. Meanwhile, the position of the U-turn intersection is automatically excavated, and the determining speed of the position of the U-turn intersection can be improved.

With regard to the apparatus in the above-described embodiment, the specific manner in which each module performs the operation has been described in detail in the embodiment related to the method, and will not be elaborated here.

EXAMPLE six

The sixth embodiment of the present application provides a non-volatile computer storage medium, where the computer storage medium stores computer-executable instructions, and the computer-executable instructions may execute the method for determining a u-turn intersection in any of the above method embodiments.

EXAMPLE seven

Fig. 17 is a schematic diagram of a hardware structure of an electronic device for executing a method for determining a u-turn intersection according to a seventh embodiment of the present application, and as shown in fig. 17, the electronic device includes:

one or more processors 1710, and a memory 1720, with one processor 1710 being illustrated in fig. 17. The electronic device executing the method for determining a u-turn intersection may further include: an input device 1730 and an output device 1740.

The processor 1710, memory 1720, input device 1730, and output device 1740 may be connected by a bus or other means, such as being connected by a bus in fig. 17.

The memory 1720 may be used as a non-volatile computer-readable storage medium to store non-volatile software programs, non-volatile computer-executable programs, and modules, such as program instructions/modules corresponding to the method for determining a u-turn intersection in the embodiment of the present application (for example, the first yaw trajectory record obtaining module 1501, the first straight-line distance obtaining module 1502, the first traversal module 1503, and the first u-turn intersection determining module 1504 shown in fig. 15). The processor 1710 executes various functional applications and data processing of the server by running the nonvolatile software program, instructions and modules stored in the memory 1720, that is, the method for determining the u-turn intersection according to the above method embodiment is implemented.

The memory 1720 may include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required for at least one function; the storage data area may store data created from use of the u-turn intersection determination device, and the like. Further, the memory 1720 may include high-speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 1720 may optionally include a memory remotely located from the processor 1710, and these remote memories may be connected to the u-turn intersection determination device via a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.

The input device 1730 may receive input numeric or character information and generate key signal inputs related to user settings and function control of the u-turn intersection determination device. The output device 1740 may include a display device such as a display screen.

The one or more modules are stored in the memory 1720 and when executed by the one or more processors 1710 perform the method for determining a u-turn intersection in any of the above method embodiments.

The product can execute the method provided by the embodiment of the application, and has the corresponding functional modules and beneficial effects of the execution method. For technical details that are not described in detail in this embodiment, reference may be made to the methods provided in the embodiments of the present application.

The electronic device of the embodiments of the present application exists in various forms, including but not limited to:

(1) mobile communication devices, which are characterized by mobile communication capabilities and are primarily targeted at providing voice and data communications. Such terminals include smart phones (e.g., iphones), multimedia phones, functional phones, and low-end phones, among others.

(2) The ultra-mobile personal computer equipment belongs to the category of personal computers, has calculation and processing functions and generally has the characteristic of mobile internet access. Such terminals include PDA, MID, and UMPC devices, such as ipads.

(3) Portable entertainment devices such devices may display and play multimedia content. Such devices include audio and video players (e.g., ipods), handheld game consoles, electronic books, as well as smart toys and portable car navigation devices.

(4) The server is similar to a general computer architecture, but has higher requirements on processing capability, stability, reliability, safety, expandability, manageability and the like because of the need of providing highly reliable services.

(5) And other electronic devices with data interaction functions.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, apparatus (device), or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (devices) and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may 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 instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may 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 which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

While the preferred embodiments of the present application have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all alterations and modifications as fall within the scope of the application.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

Claims

1. A method for determining a U-turn intersection is characterized by comprising the following steps:

traversing the straight-line distance from the track points to the track points sequenced at the head according to the sequencing sequence of the track points, and acquiring the track points of which the straight-line distance reaches an extreme value as target track points;

2. The method according to claim 1, wherein screening out target track points satisfying a u-turn intersection rule from the target track points as u-turn intersection position points comprises:

for each target track point, the following operations are executed:

respectively acquiring a track point with the minimum difference between the linear distance to the target track point and a preset linear distance threshold from the track points sequenced before and after the target track point;

calculating the value of an included angle formed by the two obtained track points and the target track point by taking the target track point as an angular vertex;

and judging whether the value of the included angle meets the preset included angle value range of the U-turn intersection, and if so, regarding the target track point as the position point of the U-turn intersection.

3. The method of claim 1 or 2, wherein prior to traversing the straight-line distance of a trace point to a trace point ordered at the top, the method further comprises:

obtaining the mean value of the linear distances from the ith, the (i + 1) th and the (i + 2) th track points to the track points sequenced at the head, and taking the mean value as the linear distance used for traversing the (i + 1) th track point;

and judging whether the (i + 2) th track point is the last track point in the yaw track record, if not, determining that i is i +1, returning to the step of obtaining the mean value of the straight-line distances from the (i) th, the (i + 1) th and the (i + 2) th track points to the track point sequenced at the head, wherein the initial value of i is any natural number.

4. The method according to claim 1 or 2, wherein before the target track points satisfying the u-turn intersection rule are screened out from the target track points as u-turn intersection position points, the method further comprises:

acquiring a track distance between two adjacent target track points in the target track points;

and judging whether the track distance is smaller than a set track distance threshold value, if so, deleting any one of the two target track points.

5. The method according to claim 1 or 2, wherein before the target track points satisfying the u-turn intersection rule are screened out from the target track points as u-turn intersection position points, the method further comprises:

acquiring the track distance from the target track point to the track point sequenced at the head;

and calculating the difference value between the linear distance from the target track point to the track point sequenced at the head and the track distance, and deleting the target track point if the difference value is greater than the preset distance difference value.

6. A method for determining a U-turn intersection is characterized by comprising the following steps:

the following operations are performed for each segment:

traversing the straight-line distance from the track point in the segment to the segment starting point, and acquiring the track point of which the straight-line distance reaches an extreme value as a target track point;

7. The method of claim 6, wherein segmenting the two or more chronological trajectory points comprises:

acquiring track points serving as segmentation starting points from the more than two track points sequenced in time sequence;

acquiring the track distance from the track point sequenced after the segmentation starting point to the segmentation starting point;

and if the currently acquired track distance reaches a preset segmentation track distance threshold value, dividing the track point which is taken as the segmentation starting point, the track point of which the track distance reaches the preset segmentation track distance threshold value and the track points between the track points into one section.

8. The method according to claim 7, wherein obtaining the track point as a segmentation starting point from the more than two track points ordered in chronological order comprises:

for the first segment, determining the track point at the head position in the more than two track points sequenced according to the time sequence as a segment starting point;

and for the segments after the first segment, calculating the track distance from the track point in the previous segment of the current segment to the starting point of the previous segment, and acquiring the track point with the minimum difference between the track distance and a preset track distance threshold of the starting point of the segment as the starting point of the segment of the current segment.

9. The method of any one of claims 6-8, wherein before traversing the straight-line distance of a locus point in the segment to the start of the segment, the method further comprises:

obtaining the mean value of the linear distances from the ith, the (i + 1) th and the (i + 2) th track points in the segment to the starting point of the segment, and taking the mean value as the linear distance used for traversing the (i + 1) th track point;

and judging whether the (i + 2) th track point is the last track point in the segment, if not, determining that i is i +1, returning to the step of obtaining the mean value of the straight-line distances from the ith, the (i + 1) th and the (i + 2) th track points in the segment to the starting point of the segment, wherein the initial value of i is any natural number.

10. The method according to any one of claims 6 to 8, wherein before the target track points satisfying the u-turn intersection rule in the segment are screened out from the target track points as u-turn intersection position points, the method further comprises:

and judging whether the track distance between two adjacent target track points in the target track points is smaller than a set track distance threshold value, if so, deleting any one of the two target track points from the target track points.

11. The method according to claim 7 or 8, wherein before the target track points satisfying the u-turn intersection rule in the segment are screened out from the target track points as u-turn intersection position points, the method further comprises:

and acquiring a difference value between a linear distance from the target track point to the starting point of the segment to which the target track point belongs and the track distance, and deleting the target track point if the difference value is greater than a preset distance difference value.

12. The method according to any one of claims 6 to 8, wherein screening out target track points satisfying a u-turn intersection rule in the segment from the target track points as u-turn intersection position points comprises:

for each target track point, the following operations are executed:

sequencing track points before and after the target track point from the yaw track record, and respectively acquiring a track point with the minimum difference between the linear distance to the target track point and a preset linear distance threshold;

and judging whether the value of the included angle meets the preset included angle condition of the U-turn intersection, and if so, regarding the target track point as the position point of the U-turn intersection.

13. A u-turn intersection determination device, comprising:

the first traversal module is used for traversing the straight-line distance from the track points to the track points sequenced at the head according to the sequencing sequence of the track points, and acquiring the track points with the straight-line distance reaching an extreme value as target track points;

14. The apparatus of claim 13, wherein the first u-turn intersection determining module comprises:

15. The apparatus of claim 13 or 14, further comprising:

the first mean value acquisition module is used for acquiring the mean values of the straight line distances of the ith, ith +1 and ith +2 track points before the first traversal module traverses the straight line distances from the track points to the track points sequenced at the head, and taking the mean values as the straight line distances for traversing the ith +1 track points;

and the first judgment module is used for judging whether the (i + 2) th track point is the last track point in the yaw track record, if not, i is equal to i +1, the step of obtaining the mean value of the straight line distances from the ith, the (i + 1) th and the (i + 2) th track points to the track points sequenced at the head is returned, and the initial value of i is any natural number.

16. The apparatus of claim 13 or 14, further comprising:

17. The apparatus of claim 13 or 14, further comprising:

the second track distance acquisition module is used for acquiring the track distance from the target track point to the track points sequenced at the head position before the target track point meeting the turn-around intersection rule is screened out by the first turn-around intersection determination module to be used as the turn-around intersection position point;

and the difference value calculating module is used for calculating the difference value between the linear distance from the target track point to the track point sequenced at the head and the track distance, and deleting the target track point if the difference value is greater than the preset distance difference value.

18. A device for determining a u-turn intersection, comprising:

the second traversal module is used for traversing the linear distance from the track point in each segment to the segment starting point to obtain a track point of which the linear distance reaches an extreme value as a target track point;

19. The apparatus of claim 18, wherein the segmentation module comprises:

20. The apparatus of claim 19, wherein the trace point determination unit that sequences the segment at the top comprises:

21. The apparatus according to any one of claims 18-20, further comprising:

the second mean value acquisition module is used for acquiring the mean value of the straight-line distances from the ith, ith +1 and ith +2 track points in the segment to the segment starting point before the second traversal module traverses the straight-line distances from the track points in the segment to the segment starting point, and taking the mean value as the straight-line distance for traversing the ith +1 track point;

and the third judging module is used for judging whether the (i + 2) th track point is the last track point in the segment, if not, the i is equal to i +1, the step of obtaining the mean value of the straight line distances from the ith, the (i + 1) th and the (i + 2) th track points in the segment to the segment starting point is returned, and the initial value of the i is any natural number.

22. The apparatus according to any one of claims 18-20, further comprising:

and the fourth judging module is used for judging whether the track distance between two adjacent target track points in the target track points is smaller than a set track distance threshold value or not, and if so, deleting any one of the two target track points from the target track points.

23. The apparatus of claim 19 or 20, further comprising:

24. The apparatus according to any one of claims 18-20, wherein the second u-turn intersection determining module comprises: