Research On Underwater Vehicle Terrain Matching Based On Improving ICCP Algorithm

The demand of underwater vehicle for long-playing and high-precision navigation is not satisfied by inertial navigation system (INS) because of the intrinsic limitation of INS. While this demand can be satisfied by terrain aided navigation.Underwater terrain aided navigation technology can not only ensure the concealment of underwater vehicle, provide precise location information and height information, but also can provide surrounding terrain information. What's more, underwater terrain aided navigation has characteristics of good concealment, high reliability and strong self-working. The algorithm studied in underwater terrain aided system is the emphasis of this paper.Iterative Closest Contour Point (ICCP) algorithm is depicted detailedly in this paper. And a few improvements for the limitations of the algorithm is proposed:In order to improve searching speed in finding the nearest point, the sliding window is adopted. And the way makes algorithm more simple and complexity of algorithm in selecting window is decreased; In order to solve the problem that ICCP algorithm diverges easily when the initial INS errors are large, Combinational Algorithm of TERCOM\ICCP\Kalman filter is introduced and the reliability of ICCP algorithm is largely improved.An integrated way is developed for the limitation of the combination algorithm in practical application. IfδXINS >ΨXNS, whereδXINS is the match position errors of INS andΨXINS is the preset threshold, then the terrain contour matching algorithm is firstly used to reduce the position errors of INS, ICCP algorithm is used to get the best matching position. Two differences is used as the measurement of Kalman filter and then INS errors are corrected. If the match position errors of INS are within range of ICCP precision permitted, ICCP algorithm is used to match directly. And optimal estimation can be got by Kalman filter and INS errors can be corrected.Finally, the simulation on the ICCP algorithm and the reliability are analyzed and the improved methods are simulated and the conclusion is obtained that the precision of combinational algorithm matching is higher than traditional algorithm.