基于PMF和TERCOM组合算法的水下地形匹配技术

Underwater Terrain Matching Techniques Based on Combination of PMF and TERCOM Algorithms

由于自主式水下航行器的导航受海水环境的影响,其定位精度不高,目前较好的解决方法之一是采用水下地形匹配辅助导航系统。本文针对该系统最核心部分的匹配算法,提出了一种定位精度更高的组合算法。为了解决质点滤波(PMF)算法存在的计算量大、收敛速度慢和对初始误差比较敏感的问题,提出了一种将地形轮廓匹配(TERCOM)算法和PMF算法进行组合的方案。首先分析了搜索区域分辨率对PMF算法的影响,然后分别对以TERCOM为粗匹配、PMF为精匹配和以PMF为粗匹配、TERCOM为精匹配的两种组合算法进行了仿真比较。结果表明,第1种组合算法无论在大起伏地形还是在平坦地形中都显示出了更快的收敛性和更高的定位精度,是一种具有较高工程应用价值的算法。

Aiming at the problems that point-mass filter（PMF） algorithm is of great computation, slow convergence and initial error sensitivity, a combination scheme of terrain contour matching（TERCOM） algorithm and PMF algorithm is proposed. Firstly, the influence of search area resolution on the PMF algorithm is analyzed. Then a combination scheme taking TERCOM for coarse matching and PMF for fine matching is simulated and compared with the other scheme tak- ing PMF for coarse matching and TERCOM for fine matching. The result shows the former scheme behaves better in convergence and positioning accuracy for both rough and flat terrains with a good engineering application.