Abstract: A vehicle location detecting system comprising:a heading sensor for detecting changes in the heading of a vehicle as it moves over streets;a distance sensor for detecting distances traveled by the vehicle;a road map memory for storing a map data base;location detecting unit for detecting a first estimated location of the vehicle; andcorrection arithmetic unit for calculating a second estimated location of the vehicle from the distances detected by the distance sensor and the changes in the heading detected by the heading sensor, for detecting an optimum vehicle location of the vehicle by calculating a degree of similarity between the second estimated location and the map data base obtained from road map memory, for calculating a first probability area of the first estimated location including an actual location of the vehicle and a second probability area of the optimum vehicle location including an actual location of the vehicle, and for correcting the second estimated location with the aid of the first esti

Abstract: A calibration apparatus of an angular-velocity detection sensor for detecting a heading of a vehicle which is used in a self-contained navigational system, comprising an angular-velocity detection unit for calculating an angular velocity from an output signal of the angular-velocity detection sensor; an integration unit for calculating a current heading of the vehicle by integrating the angular velocity and by adding the integrated angular velocity to the previous heading of the vehicle; a location and heading detection unit which estimates a location of the vehicle from the current heading calculated by the integration unit, a heading obtained by a magnetic sensor and from a distance obtained by a distance sensor and which compares the estimated location with road network data obtained from a road map memory to obtain an estimated heading of the vehicle; and a heading correction unit for calculating a difference between the heading of the integration unit and the heading of the location and heading detection

Abstract: A location detecting method for detecting the location of a vehicle within a predetermined area, comprising the steps of: outputting distance data at every predetermined interval, the distance data being representative of the distance that a vehicle has travelled; outputting heading angle data at every predetermined interval, the heading angle data being representative of the heading angle change of vehicle travel; storing road map data representative of roads; computing a present location data from the distance data and the heading angle data; computing a first limit error (E1) and a second limit error (E2) of the present location data which are determined on the basis of errors in the distance data, in the heading angle data and in the road map data; registering locations on the roads, which roads are located within the first limit error (E1) of the present location data, as estimate locations; computing correlation coefficients respectively corresponding to the registered estimate locations; selecting a co