| 摘要 |
PURPOSE:To improve reliability in measuring ship's position, by obtaining respective position moving speeds by ratio navigation and dead reckoning navigation, computing a weighted average, thereby obtaining the present ship's position. CONSTITUTION:The signal of the ship's position moving speed Vt from a dead reckoning navigation device 1 is sent to integrating circuits 3 and 4 and to a differential circuit 9. The signal of the position L'Pt from a loran device 2 is sent to a differential circuit 5, and the signal of its moving speed LVt is sent to integrating circuits 6 and 7 and a differential circuit 8. The outputs from the differential circuits 8 and 9 are sent to variance judging circuits 13 and 14 comprising squaring circuits (b) and averaging circuits (c). The variance values are sent to a k determining circuits 15. The k determining circuit receives the drift amount from a drift computing circuit 12 and manual data, and computes and outputs the (k) value. The sum 10 of the difference between the weighted added values B in a circle and F in a circle for Vt and LVt, wherein w=K<t-i+1> is a load function, and the computed value E in a circle for Vt is added to a reference position P0 in an adding circuit 11. Thus the reliable ship's position G in a circle is outputted. |
