CN-115550846-B - Mobile terminal indoor positioning method combining field intensity of wireless base station with sensor information

CN115550846BCN 115550846 BCN115550846 BCN 115550846BCN-115550846-B

Abstract

A mobile terminal indoor positioning method combining wireless base station field intensity with sensor information is characterized in that a mobile terminal receives base station signal fingerprint information and locally collects terminal sensor information of the current moment and the previous moment, a final positioning result of the current moment is calculated and obtained by traversing a positioning neighborhood of the previous moment after screening, and the terminal circularly traverses in the moving process in the mode to realize continuous positioning of a terminal track. Aiming at a base station power signal acquired by a mobile terminal, the invention predicts the advancing direction through the sensor information, improves the data characteristic and enhances the positioning accuracy.

Inventors

HE DI
ZHU YICHEN
REN XINGYU
HE ZHIJUN

Assignees

上海交通大学
北京集智数字科技有限公司

Dates

Publication Date: 20260505
Application Date: 20220916

Claims (5)

1. A mobile terminal indoor positioning method combining wireless base station field intensity with sensor information is characterized in that a mobile terminal receives base station signal fingerprint information and locally collects terminal sensor information of the current moment and the previous moment, a final positioning result of the current moment is calculated and obtained by traversing a positioning neighborhood of the previous moment after screening, and the terminal circularly traverses in the moving process in the mode to realize continuous positioning of a terminal track; the fingerprint information of the base station signal refers to the receiving power of the peripheral base station radio frequency signals which are received by the mobile terminal and keep a real-time connection state; The positioning neighborhood is that the positioning neighborhood of the mobile terminal at the previous moment is taken as a base point of a positioning grid, and the positioning neighborhood corresponds to a one-step reachable grid point which takes the positioning grid base point as the center in the geographic space; the screening is to estimate the positioning result at the current moment by adopting an optimized fusion positioning method by taking the positioning grid point of the mobile terminal at the previous moment as a base point and taking the positioning grid point and the positioning neighborhood thereof as alternative grid points of the positioning result at the current moment, wherein the estimation process is the screening process of the positioning grid point, and finally the grid point obtained by estimation is the screening result of the positioning; The optimized fusion positioning method comprises the steps of carrying out direction fusion, threshold fusion and neighborhood fusion according to priority in the positioning process, wherein a positioning result after the direction fusion is used as an initial value of the threshold fusion, the positioning result after the threshold fusion is used as an initial value of the neighborhood fusion, and the finally obtained result is the optimized fusion positioning result; The optimized fusion positioning method specifically comprises the steps that in the process of determining a positioning grid from a positioning grid at the previous moment to a positioning grid at the current moment, a positioning grid result which can execute the most fusion processing conditions is taken as a preferable object, when only the two fusion processing conditions are executed, the priority of the positioning grid result is that the direction fusion processing, the neighborhood fusion processing, the threshold fusion processing and the threshold fusion processing are superior to each other, and when only one fusion processing condition is executed, the priority of the neighborhood fusion processing, the threshold fusion processing and the direction fusion processing are superior to each other.
2. The indoor positioning method of mobile terminal according to claim 1, wherein the fingerprint information of the base station signals is RSSI values of radio frequency signals of surrounding base stations, and is specifically obtained by arranging the received RSSI values of N base stations into a two-dimensional data list, wherein the first column of the data list is the base station ID numbers of the N base stations, the sequence of the data list is arranged from small to large according to the size of the base station ID numbers, and the second column of the data list is the received RSSI values corresponding to the N base stations when the mobile terminal is at any specific positioning position of a specific scene and can receive the surrounding N base station transmitting signals.
3. The indoor positioning method of the mobile terminal according to claim 1, wherein the terminal sensor information is real-time output information including relative azimuth and position information of the mobile terminal at the current moment through an IMU sensor built in the mobile terminal, and is obtained specifically through the following modes of combining a positioning result of the mobile terminal at the current moment with a positioning result of the mobile terminal at the previous moment based on map information, sensor information and base station signal fingerprint information, so that the continuity of a positioning track is kept between the positioning result at the current moment and the positioning result at the previous moment.
4. The indoor positioning method of the mobile terminal according to claim 1, wherein the traversing is to calculate corresponding fusion positioning results for all possible neighborhood grid points with respect to the positioning grid points of the mobile terminal at the previous moment as base points, and select the neighborhood grid points meeting more fusion conditions as final current moment positioning grid results through traversing comparison; The cyclic traversal is to estimate the positioning result at the current moment by adopting an optimized fusion positioning method based on the fingerprint information of the base station signal and the information of the terminal sensor, and to end the cyclic motion trail positioning estimation.
5. The indoor positioning method of mobile terminal according to claim 1, wherein the direction fusion process is to fuse the displacement vector estimation value with the instantaneous azimuth angle θ i (t) of the mobile terminal to obtain an updated value d i_est_update (t)=(a 3 ×θ i (t)+a 4 ×Arg(d i_est (t)))×||d i_est (t) of the instantaneous displacement vector estimation value of the mobile terminal at the current moment, wherein the value is a modulo operation, arg () is an argument operation, a 3 and a 4 are two weighted weights, a 3 +a 4 =1, and a 3 >0,a 4 >0; The threshold value fusion processing refers to that when a threshold value d th of an instantaneous displacement vector of any mobile terminal is obtained, a modulus of an instantaneous displacement vector estimated value updated value after direction fusion is compared with the threshold value d th , wherein when the threshold value is exceeded, the modulus of the instantaneous displacement vector is set as the threshold value, but the argument is unchanged, and the result is a vector d i_est_update (t); The neighborhood fusion processing is to superimpose a displacement vector estimated value d i_est_update (t) after threshold fusion processing with a previous positioning result to obtain an initial grid position of current positioning, define neighborhood grids of the previous positioning result according to map information, select 8 grids adjacent to the previous positioning grids in a two-dimensional space or 26 grids adjacent to the previous positioning grids in a three-dimensional space, when the initial grid position of the current positioning does not belong to the neighborhood grids, take the grid of the previous positioning as a starting point, take a direction phasor (a 3 ×θ i (t)+a 4 ×Arg(d i_est (t)) of an instantaneous displacement vector estimated value updated value d i_est_update (t) of a mobile terminal at the current moment as a moving direction of the mobile terminal from the previous positioning grids to the current positioning grids, and take a neighborhood of which the center point of each neighborhood is nearest to the direction phasor as a neighborhood fusion grid point of the current positioning.

Description

Mobile terminal indoor positioning method combining field intensity of wireless base station with sensor information Technical Field The invention relates to a technology in the field of wireless positioning, in particular to a mobile terminal indoor positioning method combining field intensity of a wireless base station with sensor information, which is designed aiming at the specificity of power data of the wireless base station, improves the data characteristics by predicting the advancing direction through the sensor information, and enhances the positioning accuracy. Background In the wireless positioning method, the positioning method based on fingerprints has wide application, but mobile signals generated by mobile base stations such as 5G are propagated based on remote radio frequency units, namely antennas, in a region, the characteristics of the signals are weak, the distance between the signals and the base stations is difficult to estimate through the signal strength, and the accuracy of the positioning mode depending on the signal RSSI of the 5G base station is low. Because the wireless signals propagate in space, the uncertainty of the influence of physical factors such as environmental factors, signal reflection, refraction and the like on the received power or path attenuation of the received signals causes the received signals to have the same or similar received signal power in certain adjacent areas or areas with geometric symmetry positions, thereby complicating the wireless positioning problem in practical application and greatly influencing the positioning effect. Disclosure of Invention Aiming at the defects in the prior art, the invention provides a mobile terminal indoor positioning method combining the field intensity of a wireless base station with sensor information, and aiming at a base station power signal acquired by a mobile terminal, the data characteristic is improved by predicting the advancing direction through the sensor information, and the positioning accuracy is enhanced. The invention is realized by the following technical scheme: The invention relates to a mobile terminal indoor positioning method combining wireless base station field intensity with sensor information, which is characterized in that a mobile terminal receives base station signal fingerprint information and locally collects terminal sensor information at the current moment and the previous moment, and after screening, the terminal calculates and obtains the final positioning result at the current moment by traversing the positioning neighborhood at the previous moment, and the terminal circularly traverses in the moving process in the mode to realize continuous positioning of the terminal track. The fingerprint information of the base station signals is the received power of the peripheral base station radio frequency signals received by the mobile terminal and kept in a real-time connection state, preferably the RSSI value of the peripheral base station radio frequency signals, and is obtained in a specific mode that when the mobile terminal is positioned at any specific positioning position in a specific scene, the mobile terminal can receive N peripheral base station transmitting signals in a shared mode. The received RSSI values of the N base stations are arranged into a two-dimensional data list. The first column of the data list is the base station ID numbers of the N base stations, the sequence of the base station ID numbers is arranged from small to large, and the second column of the data list is the received RSSI values corresponding to the N base stations. The terminal sensor information is output information in real time through an IMU sensor built in the mobile terminal and comprises relative azimuth and position information of the mobile terminal at the current moment, and is obtained specifically through the following modes of obtaining a positioning result of the mobile terminal at the current moment relative to the previous moment based on map information, sensor information and base station signal fingerprint information and combining a positioning result at the previous moment, so that the continuity of a positioning track is kept between the positioning result at the current moment and the positioning result at the previous moment. The positioning neighborhood is that the positioning neighborhood of the mobile terminal is taken as a base point of a positioning grid at the previous moment, and the positioning neighborhood corresponds to a one-step reachable grid point which takes the positioning grid base point as a center in the geographic space. The one-step reachable grid points are corresponding to 8 peripheral grid points in the two-dimensional space in the two-dimensional positioning space and 26 peripheral grid points in the three-dimensional space in the three-dimensional positioning space. The screening is to estimate the positioning result at the current moment by adoptin