【作者】 张红伟；

【导师】 袁赣南；

【作者基本信息】 哈尔滨工程大学 ， 导航、制导与控制， 2011， 硕士

【摘要】 由于惯性导航系统(Inertial Navigation System, INS)的固有缺陷,无法满足水下潜器长时间、高精度的导航需求,而用地形辅助导航方法来修正INS的误差可以满足这一需求。水下地形辅助导航技术不仅能保障水下潜器的隐蔽性,提供给潜器精确的位置信息、高度信息,还能提供潜器周围的地形地貌信息,具有隐蔽性好、可靠性高和白主性强的特点。水下地形辅助导航技术的研究关键是其算法的研究,本文在详细描述了基于等值线的最近迭代点(Iterative Closest Contour Point, ICCP)算法之后,针对该算法的局限性提出几种改进方法。针对ICCP算法在寻找最近点过程中耗费了大量时间的问题,采用滑动窗口法来提高搜索的快速性,该方法采用经典的滑动窗口法的思想,在窗口的选取方面更简单,在某种程度上降低了算法的复杂性；针对ICCP算法在INS的初始匹配误差很大时容易发散的问题,本文提出将TERCOM算法、ICCP算法和卡尔曼滤波三种算法组合的方法,很大程度上增强了ICCP算法的可靠性。考虑到组合方法在实际应用中固有局限性,本文提出一种综合方法。具体地说,若INS的初始匹配位置误差δXINS>ΨXINS,则利用TERCOM算法、ICCP算法和卡尔曼滤波三种算法组合的方法来提高匹配精度；若初始匹配误差在ICCP匹配精度容许范围内,则省略TERCOM方法的大范围搜索,直接用ICCP算法进行匹配,然后经过卡尔曼滤波器进行最优估计,进而修正INS的导航误差,这样可以提高组合方法的实时性。最后,对ICCP算法及其改进方法进行了仿真分析,得出组合方法是有效的结论。并针对初始位置误差、测深装置误差、采样点个数和数字地图误差对ICCP算法精度的影响进行了仿真分析,得出初始位置误差越小、测深装置误差越小、数字地图噪声越小,则匹配精度越高。而采样点数并不是越多越好,采样点数在7到20之间时,匹配效果较好。最后,对地形高度熵及ICCP算法的环境适应性进行了仿真分析,得出地形信息量越大,地形高度熵值越小,则ICCP算法的匹配精度越高的结论。更多还原

【Abstract】 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.更多还原