CN108259463B

CN108259463B - Fusion compression method and system for positioning track and driving path

Info

Publication number: CN108259463B
Application number: CN201711268792.0A
Authority: CN
Inventors: 郭胜敏; 韩兴广; 杨珍珍; 夏曙东
Original assignee: Beijing Palmgo Information Technology Co ltd
Current assignee: Beijing Palmgo Information Technology Co ltd
Priority date: 2017-12-05
Filing date: 2017-12-05
Publication date: 2020-08-14
Anticipated expiration: 2037-12-05
Also published as: CN108259463A

Abstract

The invention provides a fusion compression method and a fusion compression system for a positioning track and a driving path, wherein the fusion compression method comprises the following steps: inserting the end points of the driving path into the GPS sequence; and carrying out differential compression on the GPS sequence. The inserting the end points of the driving path into the GPS sequence comprises the following steps: and inserting the end point of the driving path between two adjacent GPS points in the GPS sequence to obtain a new GPS sequence, and recording the subscript value of the inserted end point in the new GPS sequence. The invention has better compression effect than independent compression and storage by integrally expressing and storing the GPS off-line data and the driving path data, and is more convenient to use.

Description

Fusion compression method and system for positioning track and driving path

Technical Field

The invention relates to the field of computer technology and intelligent transportation, in particular to a method for expressing and compressing a moving position data track and a driving path.

Background

With the popularization of mobile Location terminals such as smartphones, a large number of Location-Based services (LBS) such as mobile phone maps, mobile phone navigation, shared travel, etc. have emerged. In the LBS service providing process, a service provider collects a large amount of positioning track data such as high-frequency GPS and Beidou, and the current mainstream positioning frequency is 1-5 seconds. The new concepts of space intelligence, knowledge discovery driven by large space data and the like, which are aroused in recent years, further mine around mass mobile position data and realize the maximization of the value of the data. Therefore, the mobile location data becomes the most important data asset of the LBS service provider, but the mobile location data is generated all the time, and how to effectively organize and store massive data becomes a difficult problem which is urgently needed to be solved by the industry.

The mobile location data is time-varying and discrete, and in order to effectively extract the spatial semantic information, the mobile location data is often mapped onto a road network based on Map Matching operation to form a traveling path of a mobile entity.

Fig. 1 is a technical route diagram of conventional processing of mobile location data in the current intelligent transportation field, as shown in fig. 1, a real-time GPS data stream is calculated by a Map Matching engine to generate a travel path of a mobile entity; meanwhile, after the real-time GPS data stream passes through the storage engine, offline GPS data is generated.

Generally, Map Matching is a process with certain technical difficulty and large calculation amount, so that the off-line GPS data is stored, and meanwhile, the driving path data of the mobile entity is also stored, so as to avoid repeating the Map Matching calculation process.

As shown in fig. 1, the conventional method stores GPS data and travel path data of a mobile entity independently. The position data collected by the mobile position subject in a certain period of time is defined as:

wherein,

uniquely identifying a mobile position entity, wherein N is the number of mobile positions collected in a time period; moving the position data from N position points

Composition, the attribute collected by each position point comprises time

And position coordinates

Wherein j is more than or equal to 1 and less than or equal to N.

The driving path generated after Map Matching operation is set as

The representation is made up of M road segments that are topologically connected in a road network.

Wherein

Is that

A road segment in the driving path ordered according to topology,

and

is mobile entity entering and exiting

The time of day.

Due to the fact that

Therefore, it is not only easy to use

The expression of (a) can be simplified as:

the traditional method stores GPS offline data and a driving path independently, and has the following problems:

(1) when the vehicle-mounted GPS data acquisition system is used, GPS offline data and driving path data are respectively extracted and are associated based on the vehicle entity ID, so that the use is inconvenient;

(2) under the assistance of a road network, the GPS data has strong correlation with a driving path, the expressed information has certain redundancy, and the compression efficiency has a further improved space; for example, both the off-line GPS data and the travel route have time information stored therein, but in the context of high frequency data, the time of the vehicle entering and exiting the travel route is necessarily related to the GPS data at a certain time.

Disclosure of Invention

In order to solve the problems, the invention takes GPS data storage as a main body, and the information of the driving path is mixed in the process of GPS storage, and integrated expression and compression are carried out.

Specifically, according to an aspect of the present invention, there is provided a method for fusing and compressing a positioning track and a driving path, including:

inserting the end points of the driving path into the GPS sequence;

and carrying out differential compression on the GPS sequence.

Preferably, the inserting the end point of the travel path into the GPS sequence includes: and inserting the end point of the driving path between two adjacent GPS points in the GPS sequence to obtain a new GPS sequence, and recording the subscript value of the inserted end point in the new GPS sequence.

More preferably, the method for restoring the new GPS sequence includes:

taking out an end point sequence according to the recorded subscript value;

establishing an index relation between a road section starting point and a road section ending point and a road section entity;

and taking the time of a GPS point at the upper stream of the subscript value of the endpoint as the time of the mobile entity driving away from the road section, and restoring complete driving path data.

Preferably, the differential compression is a binary compression storage.

According to another aspect of the present invention, there is also provided a fusion compression system for locating a track and a travel path, including:

the inserting module is used for inserting the end points of the driving path into the GPS sequence;

and the differential compression module is used for carrying out differential compression on the GPS sequence.

The invention has the advantages that: the invention has better compression effect than independent compression and storage by integrally expressing and storing the GPS off-line data and the driving path data, and is more convenient to use.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

FIG. 1 is a technical roadmap for conventional processing of mobile location data in the field of intelligent transportation in the prior art;

FIG. 2 is a schematic diagram of a preferred embodiment of the present invention;

FIG. 3 is a schematic diagram of a binary format storage definition according to the present invention;

FIG. 4 is a roadmap for an optimized mobile location data representation and storage technique;

FIG. 5 is a flowchart of a fusion compression method of a positioning track and a driving path according to the present invention;

FIG. 6 is a block diagram of a fusion compression system for positioning track and driving path according to the present invention.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

As shown in figure 2 of the drawings, in which,

is a mobile entity with 21 GPS points and the driving path is

Specifically, as shown in fig. 5, the method for fusing and compressing the positioning track and the driving path of the present invention includes the following steps:

in step S1, the end point of the travel path is inserted into the GPS sequence.

Of the original GPS sequence of

After the sequence of the road section end points is inserted into the GPS sequence, the following steps are carried out:

wherein f is_iAnd o_iRespectively corresponding to the road sections e_iThe start point and the end point of (c).

The original GPS sequence is 21 points, the original GPS sequence is changed into 26 points after the road section end points are inserted, and subscript values of the inserted end points in the new sequence are recorded.

The method for reducing the new sequence is the reverse operation:

the endpoint sequence can be extracted according to the recorded endpoint subscript value as follows:

f₁→o₁→o₄→o₆→o₈

establishing an index relation between a road section starting point and a road section ending point and a road section entity:

f₁→o₁can take out e₁，o₁→o₄Can take out e₄In the same way, the driving path can be restored to e₁→e₄→e₆→e₈；

And taking the time of a GPS point at the upstream of the end point subscript as the time of the mobile entity driving away from the road section, the complete driving path data can be restored:

step S2, the GPS sequence is differentially compressed.

Under the background of high-frequency sampling, the longitude and latitude coordinates of adjacent GPS can be compressed by a difference method because the displacement is not large.

In the case of no shift, expression

The amount of data used is less than

Fig. 3 defines a format for binary compressed storage of the inserted sequence.

The binary format is divided into a header and a data segment 2, and is specifically defined as the following table:

note: and storing no time in the binary format, and defaulting each point to be the time of increasing the sampling interval on the basis of the last point, wherein if a GPS point is missing in the middle, the contents of the longitude difference and the latitude difference of the corresponding position are vacant.

Based on the above analysis, the present invention can be integrated into the Map Matching engine to form a new technical architecture as shown in fig. 4. The invention has better compression effect than independent compression and storage by integrally expressing and storing the GPS off-line data and the driving path data, and is more convenient to use.

Accordingly, as shown in fig. 6, according to another aspect of the present invention, there is provided a fusion compression system 100 for locating a track and a travel path, comprising:

an insertion module 101, configured to insert an end point of a travel path into a GPS sequence;

and a differential compression module 102, configured to perform differential compression on the GPS sequence.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims

1. A fusion compression method for a positioning track and a driving path comprises the following steps:

inserting the end points of the driving path into the GPS sequence; inserting an end point of a driving path between two GPS points adjacent to the end point in a GPS sequence to obtain a new GPS sequence, and recording a subscript value of the inserted end point in the new GPS sequence; the method for restoring the new GPS sequence comprises the following steps: taking out an end point sequence according to the recorded subscript value; establishing an index relation between a road section starting point and a road section ending point and a road section entity; taking the time of a GPS point at the upper stream of the endpoint subscript value as the time of a mobile entity driving away from a road section, and restoring complete driving path data;

and carrying out differential compression on the GPS sequence.

2. The fusion compression method of the positioning track and the driving path according to claim 1, characterized in that:

the differential compression is binary compression storage.

3. The fusion compression method of the positioning track and the driving path according to claim 2, characterized in that:

the binary format is divided into two parts of a packet header and a data segment, and the following specific definitions are as follows:

4. a fusion compression system for positioning track and driving path comprises:

the inserting module is used for inserting the end points of the driving path into the GPS sequence; inserting an end point of a driving path between two GPS points adjacent to the end point in a GPS sequence to obtain a new GPS sequence, and recording a subscript value of the inserted end point in the new GPS sequence; the method for restoring the new GPS sequence comprises the following steps: taking out an end point sequence according to the recorded subscript value; establishing an index relation between a road section starting point and a road section ending point and a road section entity; taking the time of a GPS point at the upper stream of the endpoint subscript value as the time of a mobile entity driving away from a road section, and restoring complete driving path data;

5. The fusion compression system for positioning track and driving path according to claim 4, characterized in that:

the differential compression is binary compression storage.