haiburitsudo type position measuring device

摘要

PURPOSE:To take a measurement with higher accuracy by outputting a more reliable result between results of a radio wave navigation device and a dead reckoning navigation device and correcting the device with less reliability. CONSTITUTION:A position measuring instrument has the radio wave navigation device 1 which measures specific kinds of data on a position, an azimuth, a speed, etc., and a dead reckoning navigation device 2 which measures specific kinds of data on the position, azimuth, speed, etc., and is further provided with a reliability decision device 6 which inputs measurement data from both devices, decides which of both data have higher reliability, and outputs the more reliable measurement data and a calibrating device 7 which outputs calibration data to the device which outputs the less reliable data so that the device can outputs data nearly as reliable as the data that the more reliable device outputs. The dead reckoning navigation device 2 is equipped with an azimuth detector 4 and a range detector 5 and the azimuth detector 4 is composed of, for example, a terrestrial magnetic sensor and detects the traveling azimuth thetaI of a vehicle. Further, the range difference detector 5 outputs a unit pulse signal every time the vehicle travels by constant distance.