基于TERCOM-ICP联合算法的水下地形匹配方法研究

水下地形辅助导航一直是应用于AUV的热点和前沿问题，有助于修正惯导随时间积累的定位误差，以实现精确的导航定位。对经典地形匹配方法TERCOM算法进行了简单的介绍，引入点云配准领域的ICP算法，针对多波束测深系统可以获取地形剖面的特点，提出了一种TERCOM-ICP联合匹配算法。首先使用TERCOM算法粗匹配，将粗匹配后的大致位置作为指示输入ICP算法中进行精匹配，通过仿真实验对TERCOM算法的匹配结果和ICP算法的匹配时间作对比分析。仿真结果表明：TERCOM-ICP算法可以有效提高水下地形匹配精度，经过仿真实验测试，平均匹配误差可以达到20 m以内，所用时间在160 s以内，验证了该算法应用在水下地形匹配领域的可行性，更好地满足了水下辅助导航的要求。

Research on underwater terrain matching method based on TERCOM-ICP joint algorithm

Underwater terrain auxiliary navigation has always been the hotspot and cutting-edge problems used in AUV. It is helpful to correct the positioning error accumulated over time to achieve accurate navigation and positioning. The classical terrain matching method of TERCOM algorithm is briefly introduced, and ICP algorithm in the field of point cloud registration is introduced. On account of the characteristic that the multi-beam bathymetry system could obtain the terrain surface, a TERCOM-ICP joint matching algorithm is proposed. First, the TERCOM algorithm is roughly matched, and the rough matching position is used as an instruction in the ICP algorithm for accurate matching. Through the simulation experiment, the matching results of the TERCOM algorithm and the matching time of the ICP algorithm are compared and analyzed. The simulation results show that the TERCOM-ICP algorithm can effectively improve the accuracy of the underwater terrain matching. Through the simulation experiment, the average matching error can reach within 20 meters, and the time used is within 160 s, which verifies the feasibility of the method for underwater terrain matching, and better meets the requirements of underwater assistance navigation.