Most transport telematics applications and services such as Vehicle Navigation
Systems “VNS”, dynamic route guidance systems, fleet management, collision
avoidance systems, advanced traveler information and on-board emission monitoring
require continuous and accurate positioning information of vehicles traveling on the
road network. Many services also require real-time display of the vehicle location on a
map in an error-free fashion. Two essential components commonly used for such
applications and services are, sensors to determine the geometric position of the
vehicles, and Geographic Information Systems (GIS) based digital maps for the
identification of the physical location of the vehicles. Even with very good sensor
calibration and sensor fusion technologies, inaccuracies in the positioning sensors are
often inevitable. There are also errors associated with spatial road network data. An
interesting but challenging problem is to integrate positioning sensor data with digital
map data to improve the accuracy with which the vehicle location on a road link is
determined.
The main objectives of this research are to define reliable real time and automatic
functions, where an improved Map Matching (MM) algorithm to reconcile inaccurate
location data with inaccurate digital road network data was developed. The basic
characteristics of the algorithm take into account the historical trajectory of the vehicle,
and topological information on the road network (e.g., connectivity and orientation of
links). This then enables a precise identification of the correct link on which the vehicle
is traveling. Also, determination of the shortest path distance between source point and
destination point was implemented. |
