US 11,656,096 B1
Inertial measurement unit (IMU) based vehicles tracking
Maxim Freydin, Haifa (IL); Barak Or, Haifa (IL); and Gev Ben Haim, Hatzor Ashdod (IL)
Assigned to ALMA Technologies Ltd., Haifa (IL)
Filed by ALMA Technologies Ltd., Haifa (IL)
Filed on Apr. 28, 2022, as Appl. No. 17/731,496.
Int. Cl. G01C 21/00 (2006.01); G01C 21/34 (2006.01)
CPC G01C 21/3844 (2020.08) [G01C 21/3461 (2013.01); G01C 21/3492 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A computer implemented method of computing an estimated location of ground vehicles having no access to geolocation services based on inertial measurement unit (IMU) data, comprising:
using a server configured for computing the estimated location of ground vehicles having no access to geolocation services by:
receiving, by the server, from at least one vehicle, via at least one radio frequency (RF) communication channel, motion data comprising at least acceleration and angular velocity captured periodically by at least one IMU deployed in the at least one vehicle in a plurality of time points starting from a known initial location of the at least one vehicle;
accumulating, by the server, the motion data;
computing, by the server, based on the accumulated motion data, a measured heading angle time-series of the at least one vehicle expressing a movement direction of the at least one vehicle at the plurality of time points;
identifying, by the server, a plurality of candidate routes based on analysis of map data of an area surrounding the known initial location;
simulating, by the server, based on the map data, a respective simulated heading angle time-series for each of the plurality of candidate routes, the respective simulated heading angle time-series comprising a plurality of heading angles at a plurality of location points distributed along the respective candidate route corresponding to the plurality of time points, each of the plurality of heading angles is determined according to a road geometry at a respective one of the plurality of location points;
computing, by the server, a match score for each of the plurality of candidate routes indicative of a match between the respective simulated heading angle time-series and the measured heading angle time-series, wherein computing the match score for each candidate route comprises:
aggregating the simulated heading angle at the plurality of location points of the respective candidate route according to the plurality of time points to generate the respective simulated heading angle time-series,
computing a difference, at each of the plurality of time points, between a value of the heading angle of the respective simulated heading angle time-series and a value of the heading angle of the measured heading angle time-series, and
minimizing the difference by adjusting a distribution of the plurality of location points in the respective candidate route to reflect a different simulated speed;
ranking, by the server, the plurality of candidate routes according to the match score of their simulated heading angle time-series; and
determining, by the server, an estimated location of the at least one vehicle based on a current location of the at least one vehicle extracted from at least one highest ranking candidate route of the plurality of candidate routes.