Positioning mobile terminal based on electromagnetic signals

Patent metadata

Field	Value
Publication number	US-9749788-B2
Application number	US-201615344367-A
Country	US
Kind code	B2
Filing date	Nov 4, 2016
Priority date	Sep 24, 2014
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

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 for determining a step length of an entity associated to a radio frequency (RF) node, comprising:
receiving a signal propagation parameter of the RF node measured at a first time point;
determine a set of first position points based on the signal propagation parameter of the RF node measured at the first time point;
assigning a set of candidate moving step lengths to the first position points;
receiving a signal propagation parameter of the radio frequency (RF) node measured at a second time point;
determining a number of steps made by the entity from the first time point to the second time point;
obtaining a set of second position points based on the first position points, the number of steps and the set of candidate moving step lengths assigned to the first position points; and
analyzing the second position points based on the signal propagation parameter of the RF node received at the second time point to determine a step length of the entity;
wherein the analyzing the second position points based on the signal propagation parameter of the RF node received at the second time includes:
for a second position point, determining a proximate fingerprint of the signal propagation parameter, which is pre-sampled at a sampling point geographically proximate to the second position point;
ranking the second position point based at least in part on a comparison of the signal propagation parameter of the RF node received at the second time point and the determined proximate fingerprint of the signal propagation parameter; and
updating the set of candidate moving step lengths based on the ranking.

2. The method of claim 1 , wherein the signal propagation parameter of the RF node includes a signal strength associated with the RF node.

3. The method of claim 2 , further comprising:
receiving a fingerprint map of fingerprints of the signal propagation parameter which are pre-sampled at a plurality of sampling points in an area where the RF node is located; and
using the received fingerprint map in the determining of the first position points.

4. The method of claim 1 , further comprising:
determining an aggregation degree of the second position points based on the ranking of each second position point;
comparing the determined aggregation degree with an aggregation threshold; and
in response to the determined aggregation degree does not match the aggregation threshold, deleting a second position point that includes a ranking lower than a ranking threshold from the set of second position points.

5. The method of claim 1 , further comprising:
selecting one or more candidate moving step lengths of one or more second position points each having a ranking higher than a threshold; and
determining the step length of the entity based on the selected one or more candidate moving step lengths.

6. The method of claim 5 , further comprising:
deleting a second position point that includes a ranking lower than the ranking threshold from the set of second position points; and
generating a new second position point to replace the deleted second position point, the new second position point being generated based on the selected one or more candidate moving step lengths of the one or more second position points each having a ranking higher than the threshold.

7. The method of claim 1 , wherein a position point represents an estimate of at least one of a position and a direction of the entity.

8. A method of determining a location of an object associated to a radio frequency (RF) node, comprising:
obtaining a first signal measurement of an electromagnetic signal associated to the RF node at a first moment;
obtaining at least one initial candidate location of the RF node based at least in part on the first signal measurement;
assigning at least one moving step length for each of the at least one initial candidate location;
obtaining a second signal measurement of the electromagnetic signal associated to the RF node at a second moment;
updating location information of each of the at least one initial candidate location based on the assigned moving step length and a number of steps the objects moves between the first moment and the second moment to obtain at least one updated candidate location;
for each of the at least one updated candidate location, determining a proximate fingerprint of the signal propagation parameter, which is pre-sampled at a sampling point geographically proximate to the updated candidate location;
ranking the at least one updated candidate location based at least in part on a comparison of the second signal measurement of the electromagnetic signal associated to the RF node at the second moment and the respective determined proximate fingerprint of the signal propagation parameter;
further updating the at least one updated candidate location based on the ranking; and
determining the location of the object based at least in part on the further updated candidate location and the second signal measurement.

9. The method of claim 8 , wherein the further updating the at least one updated candidate location includes:
removing an updated candidate location having a ranking lower than a threshold from being used in the determining of the location.

10. The method of claim 8 , wherein the ranking comprises:
receiving a fingerprint map including fingerprints of the electromagnetic signal sampled at multiple sampling locations.

11. The method of claim 9 , further comprising replacing the removed updated candidate location with a new updated candidate location determined using a moving step length of a different updated candidate location having a ranking higher than the threshold.

12. The method of claim 9 , further comprising:
determining an aggregation degree of the at least one updated candidate location based on the ranking of each updated candidate location;
comparing the determined aggregation degree with an aggregation threshold; and
in response to the determined aggregation degree does not match the aggregation threshold, removing the updated candidate location having the ranking lower than the threshold.

13. The method of claim 8 , wherein the obtaining the at least one initial candidate locations of the RF node includes mapping the first signal measurement with a pre-generated signal fingerprint map to generate the at least one initial candidate locations.

14. The method of claim 8 , wherein a signal measurement includes at least one of a signal strength of an electromagnetic signal received by the RF node or a signal strength of an electromagnetic signal received from the RF node.

15. The method of claim 8 , wherein the number of steps the objects moves between the first moment and the second moment is determined through a different wearable computing device associated to the entity.

16. A wearable device, comprising:
a radio frequency (RF) component;
one or more processors; and
memory having computer-executable components stored thereon, which when executed by the one or more processor, configures the wearable device to perform acts comprising:
obtaining a signal propagation parameter of the RF component measured at a first time point;
determine at least one first location point based at least in part on the signal propagation parameter measured at the first time point;
assigning at least one candidate moving step length to the at least one first location point;
determining a number of movement steps and a direction of movement made by a person wearing the wearable device from the first time point to a second time poin

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

• G01S5/0294

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

• H04W4/029 Primary

  Location-based management or tracking services · CPC title

• H04W4/33

  for indoor environments, e.g. buildings · CPC title

• H04W64/006

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