【摘要】 针对惯性/地磁匹配组合导航系统,提出了一种基于迭代计算的地磁轮廓线匹配新算法,可以有效地修正惯导系统的初始位置误差和初始航向误差,并具有较高的实时性。首先以均方差准则建立匹配轨迹和实测地磁特征量的相关性约束,引入匹配曲线的参数化模型,通过泰勒展开并忽略高阶小项,将相关性约束简化为曲线平移位移和航向误差角的多变量表达式。然后依据相关性准则,将地磁匹配问题转化为以曲线平移位移和航向误差角为变量的非线性方程组的求解问题。采用牛顿迭代求解非线性方程组,实现地磁轮廓线匹配。最后仿真结果表明,基于迭代计算的地磁轮廓线匹配方法的最大匹配误差为传统轮廓线匹配方法的18.2%,为等值线约束迭代最近点匹配方法的7.8%,并且所提出的新方法耗时仅为5 ms,满足实时匹配要求。更多还原

【Abstract】 A novel geomagnetic contour matching algorithm based on iterative method is proposed for inertial/geomagnetic integrated navigation systems,which can correct the initial position and heading errors of INS(Inertial Navigation Systems),and lead to high real-time performance. First,the correlation constraint of the matching track and geomagnetic characteristic value is built according to MSD(Mean Square Deviation) criterion. By introducing the parameterized model of the matching track and neglecting the higher-order expanded terms of the first order Taylor expansion,the correlation constraint is translated into a mathematical expression of the displacement and initial heading error. Then the geomagnetic matching problem is converted to the solutions of nonlinear equations according to the correlation criterion. Newton iteration is applied to implement the geomagnetic matching algorithm. Simulation results indicate that the matching error of the contour matching algorithm based on iterative method is decreased to 18.2% compared to conventional contour matching method,and is decreased to 7.8% compared to ICCP(Iterated Closest Contour Point) matching method. Meanwhile,the time consumed in the proposed algorithm is only 5 ms,meeting the real-time requirement.更多还原