VEHICLE POSITIONING BY MAP MATCHING AS FEEDBACK FOR INS/GPS NAVIGATION SYSTEM DURING GPS SIGNAL LOSS

摘要

A method and apparatus of vehicle positioning uses map matching as feedback for an integrated navigation system where a map and navigation system is coupled with an inertial navigation system (INS) using low-precision vehicle sensors when the vehicle passes through a tunnel or other area suffering from GPS signal loss. The method and apparatus operates to detect whether the vehicle has reached an entry point of a tunnel, and if so, immediately starts a map matching operation to match the current vehicle position with a road link of the tunnel. The current position determined by the map matching operation is feedbacked to an integration Kalman filter thereby correcting errors caused by the vehicle sensors. The method and apparatus resumes the normal navigation operation including GPS navigation as soon as it detects that the vehicle is out of the tunnel.

主权项

1. A vehicle positioning method for a navigation system established on a smartphone with use of vehicle sensors, comprising the following steps of:
integrating, by using a processor, an inertial navigation system (INS) incorporating vehicle sensors with a map and navigation system implemented on a smartphone with use of an integration Kalman filter; producing vehicle's position estimates by the INS based on the acceleration and angular rate measurements from the vehicle sensors; producing position estimates indicating an absolute position of the vehicle by the map and navigation system which receives GPS satellite signals; detecting whether the estimated vehicle position has reached an entry point of a tunnel or has reached a point before the entry point of the tunnel by a predetermined threshold distance; when the estimated vehicle position has reached said either one of points, immediately starting a map matching operation for matching a current vehicle position with a road link of the tunnel derived from a map database; and performing a Kalman filter processing by the integration Kalman filter on the position estimates of the INS and the current vehicle position obtained by the map matching operation thereby correcting errors caused by the vehicle sensors.