CN109581451B - Indoor pseudo satellite positioning method based on carrier phase difference matching - Google Patents

Abstract

The invention discloses an indoor pseudolite positioning method based on carrier phase difference matching, and relates to the field of pseudolite indoor positioning. The method comprises the steps of firstly establishing an indoor fingerprint database of the carrier phase difference of the pseudolite, searching the maximum value of a relevant peak by comparing the phase difference of the pseudolite collected by various indoor terminals with the fingerprint database, and realizing indoor high-precision navigation and positioning by taking the coordinate corresponding to the maximum value as the current coordinate of the terminal. The method can be realized with relatively low difficulty, eliminates the influence of multipath effect on indoor positioning, and can effectively improve the accuracy of indoor navigation positioning.

Description

An indoor pseudolite positioning method based on carrier phase difference matching

technical field

The invention relates to the field of pseudolite navigation, in particular to the field of pseudolite indoor positioning, and adopts indoor positioning technology of adaptive carrier phase difference vector matching to realize indoor high-precision navigation and positioning.

Background technique

The problem of high-precision positioning in complex indoor environments has always been a technical problem. Due to the influence of multi-path and complex indoor environments, traditional indoor positioning methods have some problems and cannot achieve high-precision positioning, such as direct positioning. Using pseudolites for data calculation and positioning, due to the influence of multipath, the positioning accuracy cannot be guaranteed; the energy positioning methods of WIFI and Bluetooth are greatly affected by indoor environment changes, and the positioning accuracy cannot be guaranteed. However, the carrier phase difference between different pseudolites is used. The fingerprint database can realize high-precision indoor navigation and positioning, and has a good application prospect in large indoor buildings such as shopping malls, airport terminals and railway stations.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is: the positioning method based on pseudolite solves the problem of navigation and positioning in complex indoor environment, provides an indoor positioning method based on carrier phase difference fingerprint database, and improves the accuracy of navigation and positioning in complex indoor environment. The positioning method based on the carrier phase difference fingerprint database proposed by the present invention can well solve the problem of poor positioning performance in the indoor multipath environment of the existing method, and improve the indoor navigation positioning accuracy.

The technical scheme adopted in the present invention is:

An indoor pseudolite positioning method based on carrier phase difference matching, comprising the following steps:

(1) Select L pseudolites, divide the indoor space into M×N grids, use a high-precision measurement receiver in each grid to receive pseudolite signals, obtain the carrier phase of each pseudolite, and Calculate the carrier phase difference between different pseudolites, take the cosine value of the carrier phase difference, and then establish a fingerprint database T _MN of the indoor pseudolite carrier phase difference of size M×N×(L(L-1)/2), and Match the fingerprint library with the indoor map;

(2) After any terminal enters the room, download the fingerprint database and receive the pseudolite signal, identify the corresponding pseudolite number according to the received pseudolite signal and extract the carrier phase of the pseudolite; wherein, the received pseudolite number is K , K≤L;

然后取载波相位差向量的余弦值；(3) Select the optimal geometric configuration of the current pseudolite, find the carrier phase difference between the selected pseudolites, and arrange the carrier phase differences in the order of satellite numbers to form a carrier phase difference vector

Then take the cosine value of the carrier phase difference vector;

(4) According to the selected pseudolite number, extract the carrier phase difference cosine data of M×N points corresponding to the pseudolite number respectively in the fingerprint database, perform cross-correlation processing with the cosine value of the carrier phase difference vector point by point, and make a normalization Unification processing, forming M × N correlation values;

(5) Search for the maximum value of M×N correlation values, the coordinates corresponding to the maximum value are the current terminal position, and then convert the coordinates corresponding to the maximum value to the real position according to the indoor map and display on the map;

Complete indoor pseudolite positioning based on carrier phase difference fingerprint matching.

Wherein, the cross-correlation processing in step (4) is specifically as follows: cross-correlation processing is performed on the carrier phase difference cosine data corresponding to the pseudolite numbers of M×N points point by point and the cosine value of the carrier phase difference vector to obtain the cross-correlation coefficient q _mn :

形成M×N个相关值，即：

Form M×N correlation values, namely:

Among them, 1≤m≤M, 1≤n≤N, A is the cosine value of the carrier phase difference vector, T _mn is the value of the mth row and nth column of the fingerprint database, and norm represents the norm of the matrix.

Compared with the prior art, the present invention has the following beneficial effects:

The invention establishes a carrier phase difference fingerprint database by extracting the carrier phase difference between different pseudolites, and realizes indoor high-precision navigation and positioning through the comparison of the current collected phase difference and the fingerprint database. The accuracy can be greatly improved, and the influence of indoor multipath on positioning can be eliminated, which provides a new idea for solving the indoor high-precision positioning problem.

Description of drawings

FIG. 1 is a flowchart of a method according to an embodiment of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings. As shown in FIG. 1, an indoor pseudolite positioning method based on carrier phase difference matching disclosed in an embodiment of the present invention is disclosed, and the specific implementation includes the following steps:

Step 1. Establish an indoor pseudolite carrier phase difference fingerprint database, with L pseudolites numbered s ₁ , s ₂ , ..., s _L , then at most L(L-1)/2 carrier phase differences will be formed, Divide the indoor space into M×N grids, use a high-precision measurement receiver to collect the carrier phase of the point in each grid, and find the carrier phase difference between different pseudolites, and take the cosine of the carrier phase difference value, and then establish an indoor pseudolite carrier phase difference fingerprint database T _MN of size M×N×(L(L-1)/2), and match the fingerprint database with the indoor map;

Step 2: When any terminal enters the room, the indoor fingerprint matching database can be downloaded through WIFI, and the pseudolite signal can be received through the built-in receiving chip of the terminal. Assuming that the number of received pseudolites is K (K≤L), the received pseudolite signal can be identified according to the received pseudolite signal. Corresponding pseudolite number and extract the carrier phase of pseudolite;

The extraction process of the carrier phase can be described as follows: phase locking is achieved by using a phase-locked loop. After phase locking, the phase of the local signal of the receiver is the same as the phase of the GPS carrier signal. At this time, the difference between the phase of the local signal of the receiver and the initial phase is the carrier phase observation. quantity.

i表示收到伪卫星的下标，j表示与i不同另一颗伪卫星的下标，并将载波相位差按卫星号大小顺序排列，形成载波相位差向量

然后取载波相位差向量的余弦值，即求

Step 3: Select the optimal geometric configuration of the current pseudolite, and find the carrier phase difference between different pseudolites,

i represents the subscript of the received pseudolite, j represents the subscript of another pseudolite different from i, and the carrier phase differences are arranged in the order of satellite numbers to form a carrier phase difference vector

Then take the cosine value of the carrier phase difference vector, that is, find

1≤m≤M,1≤n≤N，A为载波相位差向量的余弦值，T_mn为指纹库第m行第n列的值，norm表示求取矩阵的范数，形成M×N个相关峰值，得到二维矩阵：

Step 4: According to the selected pseudolite number, extract the carrier phase difference cosine data of M×N points corresponding to the pseudolite number respectively in the fingerprint database, and perform cross-correlation processing with the currently received data point by point and normalize it. process, request

1≤m≤M, 1≤n≤N, A is the cosine value of the carrier phase difference vector, T _mn is the value of the mth row and nth column of the fingerprint database, norm means to obtain the norm of the matrix to form M×N Correlation peaks, resulting in a two-dimensional matrix:

Step 5: Search for the maximum value of M×N correlation values, and find out the row and column coordinates M_max, N_max corresponding to the maximum value, which can be found by peak-by-peak comparison, namely: [M_max, N_max]=max(Q _M×N ), the row and column coordinates of the maximum value can be converted into real latitude and longitude coordinates according to the latitude and longitude coordinates corresponding to the reference truth point, and displayed on the indoor map.

Complete indoor pseudolite positioning based on carrier phase difference fingerprint matching.

Claims (2)

1. An indoor pseudo satellite positioning method based on carrier phase difference matching is characterized by comprising the following steps:

(1) selecting L pseudolites, dividing the indoor space into M × N grids, receiving pseudolite signals in each grid by adopting a high-precision measurement type receiver, obtaining the carrier phase of each pseudolite, solving the carrier phase difference among different pseudolites, taking the cosine value of the carrier phase difference, and establishing a fingerprint library T of the carrier phase difference of the indoor pseudolites with the size of M × N × (L (L-1)/2)_MNMatching the fingerprint database with an indoor map;

(2) after any terminal enters the room, downloading a fingerprint library, receiving a pseudo satellite signal, identifying a corresponding pseudo satellite number according to the received pseudo satellite signal and extracting a carrier phase of the pseudo satellite; the number of the received pseudolites is K, and K is less than or equal to L;

(3) selecting the optimal geometric configuration of the current pseudolite, solving the carrier phase difference between the selected pseudolites, arranging the carrier phase difference according to the size sequence of the satellite numbers to form a carrier phase difference vector, and then taking the cosine value of the carrier phase difference vector;

(4) respectively extracting M × N points from the fingerprint database according to the selected pseudosatellite number to obtain carrier phase difference cosine data corresponding to the pseudosatellite number, performing cross-correlation processing on the point-by-point cosine data and the carrier phase difference vector cosine values, and performing normalization processing to form M × N correlation values;

(5) searching the maximum value of the M × N correlation values, wherein the coordinate corresponding to the maximum value is the position of the current terminal, and converting the coordinate corresponding to the maximum value into a real position according to an indoor map to be displayed on the map;

and completing the indoor pseudo satellite positioning based on the carrier phase difference fingerprint matching.

2. The carrier phase difference matching-based indoor pseudolite positioning method as claimed in claim 1, wherein the cross-correlation processing in step (4) is specifically that M × N points are respectively cross-correlated with the cosine data of the carrier phase difference cosine data point by point corresponding to the pseudolite number and the cosine value of the carrier phase difference vector to obtain the cross-correlation coefficient q_mn:

Form M × N correlation values, namely:

wherein M is more than or equal to 1 and less than or equal to M, N is more than or equal to 1 and less than or equal to N, A is the cosine value of the carrier phase difference vector, T_mnFor the value of the mth row and nth column of the fingerprint database, norm represents the norm of the matrix.

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