VEHICULAR NAVIGATION APPARATUS

A vehicular navigation apparatus includes a distance sensor (1), a steering angle sensor (3), a curve detecting unit (9) provided with inputs of a distance signal and steering-angle signal for calculating a change in vehicle travelling direction by referring to a steering angle - travelling direction conversion table (17), a course exploration unit (13) provided with inputs of present position and destination for performing course exploration based on intersection data, road data and node data, a comparison-decision unit (11) for comparing retrieved course data and results of curve detection, and a guidance processor (15) for executing predetermined guidance processing based on the results of comparison. Thus, it is determined whether the vehicle has turned at a guidance intersection or node on a predetermined course and whether the vehicle is on the predetermined course. If the vehicle has made a correct turn, present position is calculated by performing a distance correction using intersection position data or node data. When it is determined that the vehicle is off course, the driver is so informed and instructions can be given for measures to be taken subsequently.