Method for the localization of an individual

• US 9,933,266 B2
• Filed: 06/25/2015
• Issued: 04/03/2018
• Est. Priority Date: 06/26/2014
• Status: Active Grant

• Current Assignee: GiPSTech SRL
• Original Assignee: GiPSTech SRL
• Inventors: D'Aquila, Gaetano
• Primary Examiner(s): Dager, Jonathan M
• Assistant Examiner(s): Evans, Garrett F
• Application Number:
  US15/320,631
• Publication Number:
  US 20170176189A1
• Time in Patent Office: 1,013 Days
• Field of Search: None
• CPC Class Codes: G01C 21/12 executed aboard the object being navigated; Dead reckoning
• CPC Class Codes: G01C 21/16 by integrating acceleration or speed, i.e. inertial navigation
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G01C 21/206 specially adapted for indoor navigation
• CPC Class Codes: G01C 22/006 Pedometers
• CPC Class Codes: G06F 16/2228 Indexing structures
• CPC Class Codes: G06F 16/29 Geographical information databases

Abstract

A method for the localization of an individual, which comprises: —detecting a displacement associated with a movement of said individual; —recording environmental signals recordable during said step and forming a detected time series; —applying said displacement to the particles of a particle filter; —assigning a similarity index to each particle of the particle filter; —resampling the particle filter; —assuming, as the estimated position of the individual, the position of the particle having the greatest value of the similarity index or the center of a group of particles having a predefined common characteristic.

Claims

1. A method for the localization of an individual, which comprises:

detecting the displacement associated with a movement of said individual;

recording environmental signals during said movement, said environmental signals forming a detected time series;

applying said displacement to the particles of a particle filter only at the end of said movement;

assigning a similarity index to each particle of said particle filter;

said similarity index of each particle being a parameter having a value proportional to the similarity of said detected time series with a mapped time series which consists in a time series derived from a pre-constructed map (M) and corresponding to the time series that would be detected by said individual moving along the trajectory of said particle during said movement;

performing an operation of resampling of the particle filter which comprises making a selection of particles having a value of the similarity index that is greater than a predefined value;

assuming the position of said individual to be the centre of a group of particles, of said selection, grouped according to a predetermined criterion;

wherein the mapped time series are selected by;

first extracting from the map (M) the time series corresponding to each particle of the particle filter assuming the particle to be in movement along a rectilinear trajectory which starts from the last of its assigned coordinates and arrives at the coordinates resulting from the application of said displacement complemented by the movement direction;

then aligning, for each extracted time series, said time series extracted from map (M) with said detected time series and calculating for each of the extracted time series the similarity index of the particle to which the extracted time series is associated;

wherein said predetermined criterion provides for the formation of groups of particles having a reciprocal distance that is less than a preset value or having a variance of said environmental signals that is less than a predefined value;

wherein said formation of group of particles provides for a grouping step which comprises;

during an initialization step, associating each particle with a group to which only said particle itself belongs;

reiteratively associating with a same group all the particles having a reciprocal distance less than a predefined value (D);

interrupting the reiteration when there is no group comprising a single particle which has a distance to the other particles smaller than said predefined value (D);

assuming the position of the localization device to be the geometric centre of the most numerous group of particles.

2. The localization method according to claim 1, characterized in that said step of detecting the displacement comprises detecting a start condition and an end condition of said movement of said individual.

3. The localization method according to claim 1, characterized in that said displacement is given by the length of said movement, i.e. by the amount of space travelled during said movement and the direction of said movement.

4. The localization method according to claim 1 characterized in that said step of recording environmental signals comprises the recording of geomagnetic signals, said time series being given by the pattern of the geomagnetic field over time.

5. The localization method according to claim 1, characterized in that said step of recording environmental signals is carried out by means of a portable device carried by said individual during said movement.

6. The localization method according to claim 1, characterized in that said step of assigning to each particle of said particle filter a similarity index comprises comparing the mapped time series of each particle with said detected time series and associating each particle with a similarity index that consists in a parameter indicating the similarity between said mapped time series and said detected time series.

7. The localization method according to claim 1, characterized in that said step of comparing said mapped time series and said detected time series comprises the use of an algorithm for aligning the time series, preferably of the dynamic time warping type.

8. The localization method according to claim 1, characterized in that it comprises a preliminary mapping step which comprises:

positioning an environmental signal sensor;

recording the environmental signals detected by said sensor;

associating said detected environmental signals with the position of said sensor;

reiterating said positioning, recording and associating operations so as to form said map (M) of environmental signals associated with respective positions.