Positioning mobile terminal based on electromagnetic signals

Patent metadata

Field	Value
Publication number	US-2016094941-A1
Application number	US-201514863877-A
Country	US
Kind code	A1
Filing date	Sep 24, 2015
Priority date	Sep 25, 2014
Publication date	Mar 31, 2016
Grant date	—

Abstract

Example positioning techniques include: generating an initial particle set, randomly allocating different moving step lengths for each particle in the initial particle set, updating position information of each particle at a previous moment to obtain a current particle set, rating usability of each particle according to position information of each particle in the current particle set and a signal fingerprint received at a current moment, acquiring a moving step length of each particle having a rating higher than a first predetermined threshold in the current particle set, and updating a moving step length of each particle having a rating lower than the first predetermined threshold according to the acquired moving step length. The techniques of the present disclosure obtain a moving step length closest to the actual step length of a person, and update the moving step length in time with the change of the step length of the person.

First claim

What is claimed is:

1 . A method comprising:
matching a signal fingerprint of an electromagnetic signal received by a mobile terminal with signal fingerprints in a pre-generated signal fingerprint map at an initial positioning moment; generating a particle set according to a matching result; randomly allocating different moving step lengths for each particle in the initial particle set; updating position information of each particle in the particle set to obtain a current particle set according to a moving step number and a moving direction, detected by the mobile terminal at the current moment, and a moving step length of each particle; rating usability of each particle according to position information of each particle in the current particle set and a signal fingerprint received at the current moment; acquiring one or more moving step lengths of one or more particles having a rating higher than a first rating threshold in the current particle set; and updating one or more moving step lengths of another one or more particle having a rating lower than the first rating threshold according to the acquired moving step length.

2 . The method of claim 1 , wherein the rating usability of each particle according to position information of each particle in the current particle set and a signal fingerprint received at the current moment comprises:
acquiring position information and signal strength of a signal fingerprint closest to a respective particle in the signal fingerprint map; and rating the usability of the respective particle according to the signal fingerprint acquired at the current moment and the acquired position information and signal strength.

3 . The method of claim 1 , further comprising:
rasterizing the signal fingerprint map; and storing a corresponding relationship between each raster and an identification of a respective signal fingerprint closest to each raster.

4 . The method of claim 3 , further comprising:
querying the identification of the respective signal fingerprint closest to a respective raster in which a respective particle is located from the signal fingerprint map according to the corresponding relationship; and acquiring the position information and signal strength of the respective signal fingerprint closest to the respective particle according to the queried identification.

5 . The method of claim 1 , further comprising:
prior to acquiring one or more moving step lengths of one or more particles having a rating higher than a first rating threshold in the current particle set,
computing an aggregation degree of particles in the current particle set according to the ratings of each particle; and
determining that the aggregation degree of the particles in the current particle set is higher than the first aggregation degree threshold.

6 . The method of claim 5 , further comprising:
after the computing the aggregation degree of particles in the current particle set according to the ratings of each particle,
deleting particles having ratings lower than a second rating threshold in the current particle set, in response to determining that the aggregation degree is lower than a second aggregation degree threshold and higher than the first aggregation degree threshold;
generating new particles having ratings higher than the second rating threshold, a number of the generated new particles being equal to the number of the deleted particles, according to position information of remaining particles in the current particle set after the deleting; and
forming an updated current particle set.

7 . The method of claim 6 , further comprising:
determining a position of the mobile terminal according to the positions of the particles in the updated current particle set.

8 . The method of claim 1 , further comprising:
sampling the signal fingerprints in advance at a plurality of sampling points in an area to be positioned; and storing the signal fingerprints and corresponding position information in the pre-generated signal fingerprint map.

9 . The method of claim 1 , wherein a respective particle represents a candidate of position information, a direction, and a step length of the mobile terminal.

10 . A mobile terminal positioning device comprising:
one or more processors; and memory having stored thereon computer-executable components comprising:
a particle initialization unit that matches a signal fingerprint of an electromagnetic signal received by a mobile terminal with signal fingerprints in a pre-generated signal fingerprint map at an initial positioning moment, generates a particle set according to a matching result, and randomly allocates different moving step lengths for each particle in the initial particle set;
a particle updating unit that updates position information of each particle in the particle set to obtain a current particle set according to a moving step number and a moving direction, detected by the mobile terminal at the current moment, and a moving step length of each particle;
a particle rating unit that rates usability of each particle according to position information of each particle in the current particle set and a signal fingerprint received at the current moment;
a step length acquisition unit that acquires one or more moving step lengths of one or more particles having a rating higher than a first rating threshold in the current particle set; and
a step length updating unit that updates one or more moving step lengths of another one or more particle having a rating lower than the first rating threshold according to the acquired moving step length.

11 . The device of claim 10 , wherein the particle rating unit includes:
a fingerprint acquisition subunit that acquires position information and signal strength of a signal fingerprint closest to a respective particle in the signal fingerprint map; and a usability rating subunit that rates the usability of the respective particle according to the signal fingerprint acquired at the current moment and the acquired position information and signal strength.

12 . The device of claim 11 , wherein:
the signal fingerprint map is rasterized; and a corresponding relationship between each raster and an identification of a respective signal fingerprint closest to each raster is stored.

13 . The device of claim 12 , wherein the fingerprint acquisition subunit further:
queries the identification of the respective signal fingerprint closest to a respective raster in which a respective particle is located from the signal fingerprint map according to the corresponding relationship; and acquires the position information and signal strength of the respective signal fingerprint closest to the respective particle according to the queried identification.

14 . The device of claim 10 , wherein the computer-executable components further comprise:
an aggregation degree computation unit that computes an aggregation degree of particles in the current particle set according to the ratings of each particle.

15 . The device of claim 14 , wherein the computer-executable components further comprise:
a first acquisition control unit that, when the aggregation degree of the particles in the current particle set is higher than a first aggregation degree threshold, controls the step length acquisition unit to acquire moving step length of each particle having a rating higher than the first rating threshold in the current particle set.

16 . The device of claim 10 , wherein the computer-executable components further comprise a map generation unit that:
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Assignees

• Alibaba Group Holding Ltd

Inventors

• Shen Hui
• Yao Yunjiao
• Qian Xiao
• Ma Hanbo
• Zhang Zhipeng

Classifications

• G01S5/01

  Determining conditions which influence positioning, e.g. radio environment, state of motion or energy consumption · CPC title

• H04W4/029 Primary

  Location-based management or tracking services · CPC title

• G01S5/0294

  Trajectory determination or predictive filtering, e.g. target tracking or Kalman filtering · CPC title

• H04W4/027

  using movement velocity, acceleration information · CPC title

• H04W64/006

  with additional information processing, e.g. for direction or speed determination · CPC title