| 摘要 |
PURPOSE:To enable to display the mobile object such as cars on the display unit corresponding to a map, by obtaining the movement distance of the mark indicating the present location on the map through gating the distance pulse in the time interval converting the analog angle information. CONSTITUTION:In obtaining X and Y axis component of the moving distance of a mobile object, the analog angular information is converted into analog time length, and the distance pulse produced in response to the movement of the mobile object in the time distance is obtained through the gates 86, 86'. On the other hand, the gates 86, 86' are controlled as follows: That is, the AC electromotive force from the geomagnetism detection section is in synchronous detection at the synchronizing signal (the frequency is the same as that of the AC electromotive force) to obtain the average DC voltage. Further, the AC elecromotive force is in half wave rectification 61, this half wave rectified signal is fed to the analog switch to obtain the average DC electromotive force through the detection of the rectangular wave signal in synchronizing with the AC electromotive force and the rectangular wave signal in opposite phase with it. Further, the gates 86, 86' are opend in the ratio of the average DC voltage to the average DC electromotive voltage, the distance pulse train passing is integrated to obtain the moving distance of the X and Y axis components. |
