CN104200042B - A Tracking Method of Location Data Trajectory - Google Patents

Abstract

The present invention relates to soft project studying technological domain, a kind of location data trace tracking method is disclosed.In the present invention, comprise the steps of：A. adjacent anchor point P1 and P2 is obtained；B. the road data matched with P1 is obtained, the road key element point set in road data is obtained；C. when the P1 roads matched are curves, along vehicle traveling direction, obtain be located at before P2 successively, and progress point is used as in the point that road key element point is concentrated；D. according to P1, progress point and P2 coordinate track drafting line；Wherein, if the quantity of progress point is more than one, track drafting line is arranged according to acquisition order.Utilize the analysis to adjacent positioned point; choosing road key element point concentrates suitable point to be used as vehicle progress point; the excessively sparse trajectory caused draws untrue between improving adjacent positioned point, and carries out track drafting according to each point, obtains accurate true smooth trajectory.

Description

A Tracking Method of Location Data Trajectory

technical field

The invention relates to the technical field of software engineering research, in particular to a posterior positioning data trajectory tracking method.

Background technique

With the rapid development of my country's economy, automobiles, as a convenient means of transportation, have entered thousands of households, and the ensuing traffic problems have become increasingly serious. Urbanization road construction has developed rapidly in cities at all levels, viaducts, tunnels , mountain tunnels, etc., have solved various traffic problems in this environment.

However, the tracking of special vehicles and the management of emergency vehicles all need to adopt the posterior trajectory tracking method. Inaccurate. The trajectory of the vehicle is multi-possible. On the same road, there may be different trajectories. How to analyze these trajectories to determine the correct trajectory of the vehicle is a relatively complicated part of vehicle trajectory tracking. Areas prone to erroneous statistics and analysis.

Contents of the invention

The purpose of the present invention is to provide a positioning data trajectory tracking method, so that the positioning data can be accurately used to realize posterior vehicle historical trajectory tracking, and an accurate, true and smooth trajectory can be obtained.

In order to solve the above-mentioned technical problems, an embodiment of the present invention provides a positioning data trajectory tracking method, comprising the following steps:

A. Obtain adjacent positioning points P1 and P2;

B. Obtain the road data matched with P1, and obtain the road feature point set in the road data;

C. When the road matched by P1 is a curve, along the direction of travel of the vehicle, sequentially acquire the points located in front of P2 and in the collection of road element points as travel points;

D. Draw trajectory lines according to the coordinates of P1, travel points and P2; wherein, if the number of the travel points is more than one, arrange and draw the trajectory lines according to the order of acquisition.

Compared with the prior art, the main difference and effect of the embodiment of the present invention are: using the analysis of adjacent positioning points, selecting a suitable point in the road element point set as the vehicle travel point, and improving the sparseness between adjacent positioning points The resulting trajectory is unreal, and the trajectory is drawn according to each point to obtain an accurate, true and smooth trajectory. Realize the historical trajectory of the posterior vehicle, which can be widely used in various emergency response, monitoring and management vehicle management and tracking systems in enterprises and institutions that require refined management.

As a further improvement, in the step C, the following sub-steps are included:

If the P1 is on the same road as its previous adjacent positioning point, when obtaining the travel point, start obtaining from the starting point of the road feature point set;

If the P1 is not on the same road as the previous adjacent positioning point, when acquiring the travel point, start from the P1.

By judging the relationship between P1 and its previous adjacent positioning point, the starting position of the traveling point acquisition is determined, so that the position of the traveling point is closer to the real driving trajectory.

As a further improvement, after the step B, the following steps are included: according to the road feature point set, it is judged whether the road matched by the P1 is a straight line; if it is determined that the road matched by the P1 is a straight line, then press Calculate the interval point and its coordinates between P1 and P2 from the average vehicle speed and straight line direction; draw the trajectory line according to the coordinates of P1, interval point and P2;

If it is determined that the road matched by P1 is not a straight line, the steps C to D are executed.

Further judge whether the road where the vehicle is traveling is a straight line, and when it is not a straight line, that is, when it is confirmed as a curve, execute the method described in steps C to D, and when it is a straight line, use the calculated interval points to insert points method of drawing. When the route of the vehicle is a straight line, there is no intermediate point available for interpolation in the road feature point set, so it is necessary to perform interpolation drawing through the calculated interval points; and when the vehicle travel route is a curve, there are enough points in the road feature point set The point can be used as the traveling point in the middle of the vehicle's traveling process, making the route drawing more accurate. Specifically distinguish the travel route, so that the route drawing can speed up the drawing speed under the premise of ensuring the accuracy.

As a further improvement, after the step of determining that the road matched by P1 is a straight line, it is judged whether the distance between P1 and P2 is greater than the preset distance; The step of calculating the interval point and its coordinates between P1 and P2 in the direction; when it is determined that the distance is less than or equal to the preset distance, draw the trajectory line according to the coordinates of P1 and P2.

When the vehicle travels on a straight line, further distinguish whether the distance between the positioning points is too long. If the time is too long, you can insert interval points to smooth the trajectory. The interval points can be calculated according to the average vehicle speed and the direction of the line, which is fast and accurate; A long, direct connection between P1 and P2 is also accurate, and much faster.

As a further improvement, the number of the interval points is greater than one; each of the interval points is acquired at a first preset time interval; in the step of drawing a trajectory line according to the coordinates of P1, interval points and P2, the interval Points are listed in order of acquisition. Using the fixed time to calculate the interval point is not only easy to calculate, but also makes the route smoother.

As a further improvement, in the step of judging whether the road matched by P1 is a straight line, the judging method is: judge according to the quantity of the road feature point set; or, according to the starting point of the road feature point set, It is judged whether the middle point and the end point are on the same straight line.

The method of judging whether the road is a straight line is further refined to make the judgment fast and accurate.

As a further improvement, after the step B, the following steps are included: according to the road data, it is judged whether the P2 is on the same road as the P1; if the judgment is yes, the steps C to D are executed.

By judging whether P2 matches the road data, it can be known whether the vehicle is still on the original road after traveling from P1 to P2, and corresponding operations are performed to make trajectory drawing more realistic and accurate.

As a further improvement, after the step of judging whether the P2 and the P1 are on the same road according to the road data, the following step is further included: when the judgment is no, judging whether the acquisition time interval between the P1 and P2 is greater than The second preset time; when it is determined that the acquisition time is less than or equal to the second preset time, along the direction of vehicle travel, obtain the end point P3 of the road feature point set, and draw a trajectory line according to the coordinates of P1, P3 and P2 .

On the premise that P2 is no longer on the road matched by P1, the end point P3 of the road matched by P1 is obtained as the inflection point of the vehicle, so that the route drawing is more accurate.

As a further improvement, in the step of drawing trajectory lines according to the coordinates of P1, P3 and P2, the following sub-steps are also included:

Judging whether the distance between P1 and P2 is greater than the preset distance;

When it is determined that the distance is greater than the preset distance, the first interval point between P1 and P3 and its coordinates, the second interval point between P2 and P3 and its coordinates are calculated respectively according to the average vehicle speed and the straight line direction;

Draw a trajectory line according to the coordinates of P1, the first interval point, P3, the second interval point, and P2.

Further judge the distance between P1 and P2. If the distance is too long, you still need to obtain the distance points between P1 and P3, and between P2 and P3 to insert the drawing. If the distance is not long, you can draw a straight line. On the premise of accurately drawing the trajectory, speed up Draw speed, improve real-time performance.

Description of drawings

Fig. 1 is a flow chart of a method for tracking a location data track according to a first embodiment of the present invention;

Fig. 2 is a flow chart of a positioning data trajectory tracking method according to a second embodiment of the present invention;

Fig. 3a is a flowchart of a method for judging a straight line of a road according to a second embodiment of the present invention;

Fig. 3b is a flow chart of another method for judging a straight road according to the second embodiment of the present invention;

Fig. 4 is a flow chart of a positioning data trajectory tracking method according to a third embodiment of the present invention;

5 is a flow chart of a curve tracking method in a positioning data trajectory tracking method according to a fourth embodiment of the present invention;

Fig. 6a and Fig. 6b are position relationship diagrams of the positioning points P0 and P1 according to the fourth embodiment of the present invention, respectively.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, various embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. However, those of ordinary skill in the art can understand that, in each implementation manner of the present invention, many technical details are provided for readers to better understand the present application. However, even without these technical details and various changes and modifications based on the following implementation modes, the technical solution claimed in each claim of the present application can be realized.

The first embodiment of the present invention relates to a positioning data trajectory tracking method, the process of which is shown in Figure 1, specifically as follows:

Step 101, acquiring adjacent positioning points P1 and P2.

Specifically, in this embodiment, two adjacent positioning points P1 and P2 may be sequentially acquired from the GPS positioning data received by the vehicle. That is to say, the vehicle is driving from point P1 to point P2, that is, the subsequent drawing starts with P1 as the starting point of the vehicle.

Step 102, obtain the road data matched with P1, and obtain the road feature point set in the road data.

Specifically, the road on which the vehicle travels itself has a GIS (Geographic Information System) data map, and in the GIS data, a collection of points on the centerline of the road is used to form a road feature point set.

In this embodiment, P1 is used to match the road centerline in the GIS data to obtain the matched road centerline. The road centerline is the road data, and the road feature point set of the road is obtained according to the road data. , that is, the set of point coordinates obtained directly from the centerline. It should also be noted that the matching method of the positioning point and the road center line is obtained according to the GIS spatial topology algorithm, that is, the spatial proximity relationship between the point and the line is obtained, and the point and the line are spatially matched within a certain error range , to obtain road data.

It is worth mentioning that in this embodiment, the road line matched by point P2 is the same as point P1 by default, that is, the vehicle travels from P1 to P2 on the same road line. In addition, if the vehicle turns to other roads during driving, etc., it is not within the scope of consideration of this embodiment.

Step 103 , along the traveling direction of the vehicle, sequentially acquire the points located in front of P2 and in the collection of road feature points as traveling points.

Specifically, when the road matched by P1 is a curve, the required points are taken from the road feature point set and inserted into P2, which effectively improves the trajectory line distortion caused by too sparse positioning points. At the same time, because it is obtained sequentially, and the point where the road feature points are concentrated is used as the travel point, it is fast and accurate. The travel point is equivalent to the intermediate process point of the vehicle, which fully expresses the real route of the vehicle between P1 and P2.

It should be noted that one or more travel points can be selected. Due to the complex road conditions, especially when it is a curve, there is not only one inflection point. The more travel points are taken, the more accurate and smooth the trajectory line can be drawn. , but taking too many points will also affect the speed of trajectory line drawing. Specifically, in this embodiment, travel points are taken at intervals of a fixed time (such as 5 seconds), and the drawing speed is taken into account while ensuring the accuracy of the trajectory.

Step 104, use P1, travel point and P2 to draw.

Specifically, the trajectory line is drawn according to the coordinates of P1, the traveling point, and P2.

It should also be noted that if the number of travel points is greater than one, the trajectory lines are arranged and drawn according to the order in which they are obtained.

Compared with the prior art, the main difference and effect of this embodiment are: using the analysis of adjacent positioning points, selecting a suitable point in the road element point set as the vehicle travel point, and improving the problem caused by the sparseness between adjacent positioning points. The trajectory of the vehicle is not real, and the road matching and identification of vehicle trajectory under complex road conditions is realized, and the trajectory is drawn according to each point to obtain an accurate, true and smooth trajectory. It can quickly and accurately realize the historical trajectory of the posterior vehicle, and can be widely used in various emergency response, monitoring and management vehicle management and tracking systems in enterprises and institutions that require refined management.

It is worth mentioning that the positioning data trajectory tracking method in this embodiment is only based on the analysis of a group of adjacent positioning points (equivalent to "data pairs") and road data, and the trajectory line drawing is carried out. After completing P1 and P2 After the drawing of the interval, it will return to step 101 by using the iterative method of traveling, change P2 into the first positioning point P1 in this embodiment, and then obtain the next positioning point P' as the second positioning in this embodiment At point P2, repeat the positioning data trajectory tracking method in this embodiment. That is to say, in practical applications, it is only necessary to use the iterative method during travel, that is, by repeating this process, the trajectory of the vehicle can be continuously drawn according to the positioning data during the travel of the vehicle.

In addition, this embodiment can be further optimized. Before the process enters the next cycle, it can also be added to determine whether there are other vehicle positioning trigger conditions, and if so, it can be transferred to process other trigger events. The trigger event may include: 1. Trigger the display of the surrounding area of the power station (for example, within a radius of 1 km) according to the user-set conditions, and display a button to ask whether to calculate the optimal route. 2. When the power is insufficient, trigger the display button to ask whether to calculate the optimal path. 3. Other extended processing can be performed as required. Of course, the trigger event here can be set to not execute the trigger function by default, because the trigger condition will occupy resources.

The second embodiment of the present invention also relates to a positioning data trajectory tracking method. The second embodiment is further improved on the basis of the first embodiment. The main improvement is that in the first embodiment, appropriate points are selected from the road feature point set and inserted between adjacent anchor points. However, in the second embodiment of the present invention, a method of selecting a suitable intermediate point when the vehicle is driving on a straight road is newly added. When drawing a straight line trajectory, more interpolation methods are provided, so that the positioning data trajectory tracking method in this embodiment is faster.

Specifically, the flow chart of the positioning data trajectory tracking method in this embodiment is as shown in Figure 2, specifically as follows:

Steps 201 to 202 are similar to steps 101 to 102 in the first embodiment, and will not be repeated here.

Similarly, if the vehicle turns to other roads during the driving process from P1 to P2, it is not within the scope of consideration of this embodiment.

Step 203, judging whether the road matched by P1 is a straight line; if yes, execute step 106; if not, execute step 104.

Specifically, since the traveling route of the vehicle may be a straight line or a curved line, it is analyzed and differentiated to implement different trajectory drawing methods, so that the drawing of the trajectory line is not only accurate, but also faster.

It should also be noted that, in this embodiment, it is judged whether the road is a straight line according to the number of road element points, and the judgment process is as shown in Figure 3a, specifically as follows:

In step 301, it is judged whether the number of point-concentrated points exceeds two; if so, it is judged that the road is a curve; if not, it is judged that the road is a straight line.

The inventors of the present invention found that, generally, when the road is a straight line, only two points of the starting point and the ending point are collected in the collection of road feature points. That is to say, when the number of decision point sets does not exceed two, it is regarded as a straight line, and if it exceeds two, it is regarded as a curve. The method is simple and practical, and the judgment is quick.

In addition, in practical applications, the actual road often has an approximate straight line, that is, although there is an inflection point, the direction change is small, and the overall road can still be approximated as a straight line for trajectory drawing. In this case, it can be judged according to whether the starting point, middle point and end point of the road feature points are on the same straight line. The coordinates of the end point Pc are (X1, Y1), the coordinates of the end point Pc are (X2, Y2), and the coordinates of the middle point Pb are (X, Y). The judgment function of the point on the line is as follows:

Specifically, if the calculated minimum distance from the Pb point to the straight line formed by the Pa and Pc points in the above function is smaller than the preset value, it can be judged that the road line is a straight line.

It is worth mentioning that, on the premise that the road line matched by P1 is not a straight line, it can be known that the road line is a curve, and P1 and P2 may be at the two ends of the turning point of the curve. If the line is drawn directly, the trajectory line will be distorted. Therefore, using the intermediate interpolation method from step 204 to step 205 can greatly improve the distortion of the trajectory. In practical applications, even if the road matched by P1 is a straight line, the method of obtaining the traveling point mentioned in step 204 can also be used to interpolate between P1 and P2 by using the traveling point. High, on the premise of ensuring the accuracy, it is also necessary to ensure the drawing speed, so using the method of this step, the drawing speed is greatly accelerated.

Steps 204 to 205 are similar to steps 103 to 104 in the first embodiment, and will not be repeated here.

Step 206, judging whether the distance between P1 and P2 is greater than the preset distance; if yes, execute step 208; if not, execute step 207.

According to the characteristics of a straight line, two points can confirm the route, and in this embodiment, in order to avoid the route distortion due to the distance between adjacent positioning points being too far away, a further judgment is made on the distance between P1 and P2, that is, the distance between P1 and P2 Whether the distance exceeds the preset distance is judged. If it exceeds, it is judged as too far;

Step 207, use P1 and P2 to draw.

Specifically, on the premise that P1 and P2 are on a straight line and the distance is relatively close, an accurate trajectory can be drawn by directly connecting two points, that is, using the coordinates of P1 and P2 to draw the trajectory .

Step 208, calculate the interval point and its coordinates between P1 and P2 according to the average vehicle speed and the straight line direction.

Specifically, using interval points to insert P1 and P2 can make the points denser when drawing, and improve the trajectory line distortion caused by too sparse positioning points.

It is worth mentioning that the average speed here can be the average speed of the vehicle between P1 and P2, or it can be the vehicle speed obtained last time. Generally, there will be no large error, and it can also be adjusted according to actual needs during design. Sure.

It should be noted that there may be multiple interval points, and the interval calculation is done at the first preset time, and the interval points calculated by using a fixed time are not only easy to calculate, but also make the route smoother. For example, 5 seconds can be set as the time interval.

Step 209, use P1, interval points and P2 to draw.

Specifically, the trajectory line is drawn according to the coordinates of P1, interval points and P2.

It should be noted that if there are multiple interval points at this time, they need to be arranged according to the order in which each interval point is obtained when drawing.

The third embodiment of the present invention relates to a positioning data trajectory tracking method. The third embodiment is further improved on the basis of the second embodiment, and the main improvement is that in the second embodiment, adjacent positioning points can only be on the same road line. In the second embodiment of the present invention, adjacent positioning points may not be on the same road line, so that when the trajectory is drawn, more interpolation methods are provided, so that the positioning data trajectory tracking method in this embodiment is more in line with reality. Draw a more realistic and accurate route trajectory based on the changing situations encountered.

The flowchart in this embodiment is shown in Figure 4, specifically as follows:

Steps 401 to 402 are similar to steps 101 to 102 in the first embodiment, and will not be repeated here.

Step 403, determine whether P2 is on the road matched by P1; if yes, execute step 404; if not, execute step 411.

Specifically, through the matching of P2 and the road centerline in the GIS data, it is judged whether P2 matches the road data matched by P1, that is to say, whether the positioning point P2 and the current road element are on the same line , that is, to determine whether P2 and P1 are on the same road.

More specifically, if the determination is yes, it is determined that P2 is on the road matched by P1, that is, P2 and P1 are on the same straight line, so it is determined that P2 is a continuation point of P1 rather than a new point; if If the judgment is no, it is judged that P2 is not on the road matched by P1, that is, it is judged that the positioning point P2 and P1 are not on the same straight line, but whether P1 is a new point needs to be further judged in the subsequent step 411 .

Steps 404 to 410 are similar to steps 103 to 109 in the first embodiment, and will not be repeated here.

Step 411, judging whether the acquisition time interval of P1 and P2 is greater than the second preset time; if yes, execute step 412; if not, end the process.

Specifically, P1 and P2 are not on the same road line, and two situations may occur, which may be that the vehicle encounters a corner of the road, or the vehicle travels to another route. By judging the acquisition time interval between P1 and P2, if the acquisition time interval between P1 and P2 is too long, it means that the vehicle has gone to another route at P2, that is, P2 is a new point, not a continuation point, and P1 has no connection, then use P2 as the starting point, and start drawing after combining the received positioning points. After the two situations are distinguished, different drawing methods can be carried out respectively to realize accurate drawing of the vehicle trajectory.

Step 412 , along the traveling direction of the vehicle, acquire the end point P3 in the set of road feature points.

Specifically, since the time interval between P1 and P2 is not too long, it can be known that P1 and P2 are not on the same road line because the vehicle has passed the inflection point, that is, P2 at this time is the continuation point of P1, and If it is not a new point, then the simplest drawing operation at this time can directly perform coordinate drawing in the order of P1-P3-P2.

It is worth mentioning that since the road line itself is a vector line, it also has an end point, but the end point here refers to the end point determined according to the traveling direction of the vehicle, not the end point of the road line itself.

Step 413 , judging whether the distance between P1 and P2 is greater than the preset distance; if yes, execute step 409 ; if not, execute step 414 .

Specifically, this step is similar to the judgment in step 106 in the first embodiment, and will not be repeated here. It is worth mentioning that in the programming of such similar steps in the whole process, the "private member" design method can be used to reduce the amount of calculation and power consumption.

In this embodiment, in order to make the trajectory drawing more real and accurate, this step is used to further distinguish and judge, that is, to judge whether the distance between P1 and P2 is too sparse, and whether interpolation encryption is required in the middle.

Step 414, use P1, P2 and P3 to draw.

Specifically, the trajectory line is drawn according to the coordinates of P1, P3 and P2.

The fourth embodiment of the present invention relates to a positioning data trajectory tracking method. The fourth embodiment is further improved on the basis of the first embodiment. The main improvement is that in the first embodiment, when it is determined that the road line matched by P1 is a curve, the method of obtaining the travel point is directly used. method for interpolation drawing, and in this embodiment, a further judgment is made on the approximate position of P2 on the road line, so as to further distinguish the direction and order when obtaining the traveling point, so that the obtaining of the traveling point is faster and further Speed up the drawing speed of the trajectory line in the positioning data trajectory tracking method in this embodiment.

In this embodiment, the tracking method when the road line is a curve is to further refine the judgment of step 104 in the first embodiment. As shown in Figure 5, specifically, the starting point PP1 and the ending point PP2 are taken out from the road feature point set, compared with P1 respectively, and the index search is started from the end point closer to P1, and all points between P1 and P2 are obtained As an intermediate process point where the vehicle travels.

It is worth mentioning that in step 501 and step 502 in this embodiment, it is also possible to further judge whether P1 and the last adjacent positioning point of P1 are on the same road, specifically, if they are on the same road, obtain the travel point , start from the starting point in the road feature point set; if not on the same road, start from P1 when obtaining the traveling point. For example, if the last adjacent positioning point of P1 is P0, the road line A-PP1 is a straight line, PP1-PP2 is a curve, and P1 is on the curve PP1-PP2, there are two situations for the position of P0, as follows:

If the position of P0 is shown in Figure 6a, and P0 and P1 are not on the same line, then P1 is the positioning point obtained for the first time after the vehicle travels to the curve. When obtaining the traveling point, it needs to be obtained from the starting point PP1 of the road , in case the trajectory is inaccurate because the middle of the PP1-P1 segment is too sparse.

If the position of P0 is shown in Figure 6b, and P0 and P1 are on the same line, then P1 is the positioning point not obtained for the first time after the vehicle travels to the curve. When obtaining the traveling point, it only needs to be obtained from P0. The trajectory of the PP1-P0 segment has been drawn in the trajectory drawing of the previous cycle.

The division of steps in the above methods is only for the sake of clarity of description. During implementation, they can be combined into one step or some steps can be split and decomposed into multiple steps. As long as they contain the same logical relationship, they are all within the scope of protection of this patent. ; Adding insignificant modifications or introducing insignificant designs to the algorithm or process, but not changing the core design of the algorithm and process are all within the scope of protection of this patent.

Those of ordinary skill in the art can understand that the above-mentioned embodiments are specific examples for realizing the present invention, and in practical applications, various changes can be made to it in form and details without departing from the spirit and spirit of the present invention. scope.

Claims (9)

1. A positioning data track tracking method, is characterized in that, comprises the following steps: A. Obtain adjacent positioning points P1 and P2; B. Obtain the road data matched by P1, and obtain the road feature point set in the road data; C. When the road matched by P1 is a curve, along the direction of travel of the vehicle, sequentially acquire the points located in front of P2 and in the collection of road element points as travel points; D. Draw the trajectory line according to the coordinates of P1, the traveling point and P2; wherein, if the number of the traveling points is greater than one, arrange and draw the trajectory line according to the order of acquisition; Wherein, in the step C, the following sub-steps are included: If the P1 is on the same road as its previous adjacent positioning point, when obtaining the travel point, start obtaining from the starting point of the road feature point set; If the P1 is not on the same road as the previous adjacent positioning point, when acquiring the travel point, start from the P1. 2. The positioning data track tracking method according to claim 1, characterized in that, after the step B, the following steps are included: According to the set of road feature points, it is judged whether the road matched by P1 is a straight line; When judging that the road matched by said P1 is a straight line, then calculate the interval point and coordinates thereof between P1 and P2 according to the average vehicle speed and the straight line direction; draw the trajectory line according to the coordinates of P1, interval point and P2; If it is determined that the road matched by P1 is not a straight line, the steps C to D are executed. 3. The positioning data trajectory tracking method according to claim 2, wherein the number of the interval points is greater than one; each of the interval points is acquired with a first preset time interval; In the step of drawing the trajectory line according to the coordinates of P1, interval points and P2, the interval points are arranged in order of acquisition. 4. The positioning data trajectory tracking method according to claim 2, characterized in that, after the step of determining that the road matched by P1 is a straight line, it is judged whether the distance between P1 and P2 is greater than a preset distance; When it is determined that the distance is greater than the preset distance, the step of calculating the interval point and its coordinates between P1 and P2 according to the average vehicle speed and the straight line direction is executed; When it is determined that the distance is less than or equal to the preset distance, the trajectory line is drawn according to the coordinates of P1 and P2. 5. The positioning data trajectory tracking method according to claim 2, wherein, in the step of determining whether the road matched by the P1 is a straight line, the method for judging is: Judging according to the quantity of the road feature point set; or, Judgment is made according to whether the start point, intermediate point and end point of the set of road feature points are on the same straight line. 6. The positioning data trajectory tracking method according to claim 1, characterized in that, after the step B, comprising the following steps: judging whether the P2 is on the same road as the P1 according to the road data; When the judgment is yes, the steps C to D are executed. 7. The positioning data trajectory tracking method according to claim 6, characterized in that, after the step of judging whether said P2 is on the same road as said P1 according to said road data, the following steps are also included: When the judgment is no, it is judged whether the acquisition time interval of P1 and P2 is greater than the second preset time; When it is determined that the acquisition time is less than or equal to the second preset time, along the traveling direction of the vehicle, the end point P3 in the set of road feature points is acquired, and a trajectory line is drawn according to the coordinates of P1, P3 and P2. 8. The positioning data trajectory tracking method according to claim 7, wherein, in the step of drawing trajectory lines according to the coordinates of P1, P3 and P2, the following sub-steps are also included: Judging whether the distance between P1 and P2 is greater than the preset distance; When it is determined that the distance is greater than the preset distance, the first interval point between P1 and P3 and its coordinates, the second interval point between P2 and P3 and its coordinates are calculated according to the average vehicle speed and the straight line direction; Draw a trajectory line according to the coordinates of P1, the first interval point, P3, the second interval point, and P2. 9. The positioning data trajectory tracking method according to claim 8, wherein the number of the interval points is greater than one; each of the interval points is acquired at a first preset time interval; In the step of drawing the trajectory line according to the coordinates of P1, the first interval point, P3, the second interval point and P2, the first interval point and the second interval point are arranged in order of acquisition.