阅读说明：本技术 一种gps定位轨迹的噪声点漂移去除方法 (Noise point drift removal method for GPS positioning track ) 是由 王秋霖 卿明 童静 姚宇 于 2020-05-08 设计创作，主要内容包括：本发明提供一种GPS定位轨迹的噪声点漂移去除方法,包括以下流程中的一种或者几种：S1：去除不符合几何学特征的噪声漂移奇异点；S2：去除加速度约等于重力加速度的漂移点；S3：去除运动距离大于计步器估计距离的漂移点；S4：去除相邻距离很小的临近漂移点；S5：对定位轨迹进行平滑滤波以平滑几何突变噪声点。本发明引入了几何算法、加速度计融合定位、计步器融合定位、重复点去除、平滑滤波,更加智能化,能将99％以上的轨迹漂移点进行去除,从而使定位轨迹更加接近真实轨迹,可视化效果也更佳,不仅可进行实时定位的矫正,也可实现回放轨迹的矫正,本发明的方法普遍适用于GPS、GLONASS、BDS和GALILEO四大全球卫星的定位轨迹噪声点去除和室内定位的噪声点去除。(The invention provides a method for removing noise point drift of a GPS positioning track, which comprises one or more of the following processes: s1: removing noise drift singular points which do not accord with geometric characteristics; s2: removing drift points with acceleration approximately equal to the acceleration of gravity; s3: removing drift points of which the movement distance is greater than the estimated distance of the pedometer; s4: removing adjacent drifting points with small adjacent distances; s5: and carrying out smooth filtering on the positioning track to smooth the geometric abrupt change noise points. The method introduces a geometric algorithm, accelerometer fusion positioning, pedometer fusion positioning, repeated point removing and smooth filtering, is more intelligent, and can remove more than 99% of track drift points, so that the positioning track is closer to a real track, the visualization effect is better, the correction of real-time positioning can be performed, and the correction of playback track can also be realized.)

1. A noise point drift removing method for a GPS positioning track is characterized by comprising one or more of the following processes:

s1: removing noise drift singular points which do not accord with geometric characteristics;

s2: removing drift points with acceleration approximately equal to the acceleration of gravity;

s3: removing drift points of which the movement distance is greater than the estimated distance of the pedometer;

s4: removing adjacent drifting points with small adjacent distances;

s5: and carrying out smooth filtering on the positioning track to smooth the geometric abrupt change noise points.

2. The method for removing the noise point drift of the GPS positioning track according to claim 1, wherein the method for removing the noise that does not conform to the geometric characteristics in the process (S1) is:

a1. traversing all the points by using a computer algorithm, and respectively calculating the distance d1 between the point and the previous point, the distance d2 between the point and the next point and the distance d3 between the previous point and the next point for any given point;

a2. judging whether the sum of d1 and d2 is more than 1.5 times d 3;

a3. if the value is larger than the preset value, the point is indicated as a geometric drift point, and the point is deleted.

3. The method for removing the drift of the noise point of the GPS positioning track according to claim 1, wherein the method for removing the drift point of the acceleration approximately equal to the acceleration of gravity in the process (S2) is:

b1. collecting acceleration values of an accelerometer in the same moment and different directions;

b2. calculating an absolute value of a difference between an acceleration value and a gravitational acceleration

b3. If the absolute value of this difference is less than 0.2, then the point is considered to be the resting point and the point is considered to be the drift point deletion.

4. The method for removing the noise drift of the GPS positioning track according to claim 1, wherein the method for removing the drift points with the moving distance greater than the estimated distance of the pedometer in the process (S3) comprises:

c1. collecting the step counting number of the pedometer between two adjacent points;

c2. if the counting number is in the range of [2,10000], the process is considered as a walking state;

c3. if the walking state is detected, calculating the step number 1.0m as the maximum walking distance;

c4. and if the distance between adjacent positioning points is greater than the maximum walking distance, regarding the point as a noise point, and deleting the noise point.

5. The method for removing the noise drift of the GPS positioning track according to claim 1, wherein the method for removing the adjacent drift points with small adjacent distance in the process (S4) is:

d 1: calculating the distance between two adjacent points;

d 2: if the distance between two adjacent points is smaller than a set threshold value, the motion of the point is considered to belong to noise motion, and the point is considered to be stationary;

d3. the noise motion point is deleted.

6. The method for removing the noise point drift of the GPS positioning track according to claim 1, wherein the method for smoothing the positioning track to smooth the geometrically abrupt noise point in the process (S5) is:

e 1: carrying out smooth filtering with adjacent 5 points as filtering units on the positioning track;

e 2: the filtered track can reduce the interference of white noise and is a positioning track closer to a real track.

Technical Field

The invention relates to the technical field of GPS, in particular to a method for removing noise point drift of a GPS positioning track.

Background

A Global Navigation Satellite System (GNSS) is a Satellite System that can provide Global, all-weather, and all-time high-precision geographical position information and Navigation and time service information. This is a satellite system consisting of 24 satellites covering the world. The system can ensure that 4 satellites can be observed at any point on the earth at any time, so that the satellite can acquire the longitude and latitude and the height of the observation point, and functions of navigation, positioning, time service and the like can be realized. This technique can be used to guide aircraft, ships, vehicles, and individuals to safely and accurately follow a selected route to a destination on time. The four global satellite navigation systems of GPS, GLONASS, BDS and GALILEO have been able to continuously provide navigation positioning services to various users. Under the conventional condition, the positioning precision of the GPS is very high, and after the modernization is completed, the navigation positioning service of a sub-meter level can be provided for global users.

In addition, noise interference of data received instantly by a GPS transmitter and a receiver can also cause noise drift points on the GPS positioning track. Furthermore, movement of the GPS receiver may cause jitter in the received data resulting in noisy offset points of positioning. These noise offsets will cause positioning errors and affect the next various applications based on positioning, such as navigation applications. Therefore, it is necessary to remove the GPS noise offset for positioning and its application.

At present, the main method for removing noise drift points is fusion positioning of various GNSS systems, such as Beidou/GPS fusion positioning, but the fusion positioning has the following difficulty: 1) unification of different coordinate systems is required; 2) unification of time scales is required; 3) a more complex star selection algorithm is required; 4) when the satellite searching signal quality of the GPS signal is not good, the satellite searching signal quality of the Beidou is not good, so that the optimization effect of fusion positioning is limited.

An effective solution to the problems in the related art has not been proposed yet.

Disclosure of Invention

The invention aims to provide a method for removing noise point drift of a GPS positioning track so as to solve the problem of singular point drift in the middle of the positioning track.

In order to achieve the purpose, the invention provides the following technical scheme:

a noise point drift removing method for a GPS positioning track comprises one or more of the following processes:

s1: removing noise drift singular points which do not accord with geometric characteristics;

s2: removing drift points with acceleration approximately equal to the acceleration of gravity;

s3: removing drift points of which the movement distance is greater than the estimated distance of the pedometer;

s4: removing adjacent drifting points with small adjacent distances;

s5: and carrying out smooth filtering on the positioning track to smooth the geometric abrupt change noise points.

Further, the method for removing the noise that does not conform to the geometric features in the process S1 is as follows:

a1. traversing all the points by using a computer algorithm, and respectively calculating the distance d1 between the point and the previous point, the distance d2 between the point and the next point and the distance d3 between the previous point and the next point for any given point;

a2. judging whether the sum of d1 and d2 is more than 1.5 times d 3;

a3. if the value is larger than the preset value, the point is indicated as a geometric drift point, and the point is deleted.

Further, the method for removing the drift point of the acceleration approximately equal to the gravitational acceleration in the process S2 is:

b1. collecting acceleration values of the accelerometers at the same moment;

b2. calculating an absolute value of a difference between an acceleration value and a gravitational acceleration

b3. If the absolute value of this difference is less than 0.2, then the point is considered to be the resting point and the point is considered to be the drift point deletion.

Further, the method for removing the drift point of which the movement distance is greater than the estimated step counter distance in the process S3 is as follows:

c1. collecting the step counting number of the pedometer between two adjacent points;

c2. if the counting number is in the range of [2,10000], the process is considered as a walking state;

c3. if the walking state is detected, calculating the step number 1.0m as the maximum walking distance;

c4. and if the distance between adjacent positioning points is greater than the maximum walking distance, regarding the point as a noise point, and deleting the noise point.

Further, the method for removing the adjacent drift points with small adjacent distances in the process S4 is as follows:

d 1: calculating the distance between two adjacent points;

d 2: if the distance between two adjacent points is smaller than a set threshold value, the motion of the point is considered to belong to noise motion, and the point is considered to be stationary;

d3. the noise motion point is deleted.

Further, the method for performing smooth filtering on the positioning track to smooth the geometric abrupt change noise point in the process S5 is:

e 1: carrying out smooth filtering with adjacent 5 points as filtering units on the positioning track;

e 2: the filtered track can reduce the interference of white noise and is a positioning track closer to a real track.

The invention can greatly delete a large number of singular points in the GPS positioning track by the noise point removing method, so that the final positioning track is clearer, more reasonable and more accurate.

The method is not only suitable for removing the track noise points of the GPS, but also generally suitable for removing the positioning track noise points of four global satellites of the GPS, the GLONASS, the BDS and the GALILEO, and simultaneously, the method is also suitable for removing the noise points of indoor positioning, including noise point removal in the fields of geomagnetic positioning, wifi positioning, zigbee positioning, UWB positioning, Bluetooth positioning, RFID positioning, ultrasonic positioning and the like.

The working principle of the invention is as follows: all the positioning systems are highly similar, and based on a given positioning system, the positioning tracks are collected, and then noise drift points are removed based on the positioning tracks, so that the positioning tracks are closer to the real situation.

Compared with the prior art, the invention has the following beneficial effects: 1. the invention introduces a geometric algorithm, accelerometer fusion positioning, pedometer fusion positioning, repeated point removal and smooth filtering, and is more intelligent; 2. the invention does not depend on the improvement and the upgrade of the hardware of the GPS, but carries out the auxiliary noise point removal from other dimensions; 3. the method can remove more than 99% of track drift points, so that the positioning track is closer to a real track, and the visualization effect is better; 4. the method has low calculation complexity, and can realize real-time drift point removal on common calculation equipment; 5. the method can not only correct the real-time positioning, but also correct the playback track.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic flow chart of a method for removing noise point drift of a GPS positioning track according to the present invention.

Detailed Description

The invention is further described with reference to the following drawings and detailed description: