NAVIGATION SYSTEM HAVING ADVANCE INSTRUCTING FUNCTION

PURPOSE:To inform the driver of the advancing direction, by setting a circular specified region with each intersection in road map data as a center, and obtaining the angular distance between the advancing direction of an automobile and the azimuth to the destination at that point when the automobile enters the specified region. CONSTITUTION:A CPU1 has a function for controlling the entire system. An azimuth sensor 2 detects the absolute azimuth. An azimuth sensor 3 generates the output of a relative azimuth. A vehicle speed pulse sensor 4 inputs the running distance of an automobile to the CPU1 and generates pulses in correspondence with the speed of the vehicle. An operating switch part 5 inputs the running conditions of the automobile to the CPU1. An outer memory device 6 stores the road map data and the like. A color CRT7 displays the road map data and the like. A speech signal amplifier 8 and a speaker 9 are provided. Thus the advancing direction of the vehicle at an intersection can be transmitted to the driver in audio manner by the short-time set up before driving. The direction can be displayed on the CRT.