基于改进A*算法的水下重力匹配导航路径规划

水下重力匹配导航作为辅助手段，能够有效克服惯性导航系统在水下长时间航行产生的误差积累.重力场的不规则性，使得不同海域重力场适配性存在差异，重力特征变化显著的海域匹配精度较高，反之精度较低.在适配性评价基础上，对导航路径进行规划有助于提高作业任务可行性，合理规避不利因素.本文采用重力异常标准差、粗糙度等特征参数对海域重力场适配性进行评价，形成重力场适配格网参考图，引入A^*算法规划起始点和目标点间路径，达到了有效规避非适配区、提高航路设计合理性的目的.传统A^*算法存在的问题是，规划路径折线较多、线路总弯曲度大，本文设计了一种改进方法，通过前后向对比分析，对单个路径节点逐个进行筛选过滤，有效减少了冗余航向调整，实现了路径的平滑优化.

Path planning for gravity aided navigation based on improved A* algorithm

As an auxiliary method,underwater gravity matching navigation can effectively overcome the error accumulation of the inertial navigation system caused by long time underwater navigation.The irregularity of the gravity field makes the adaptability different in different ocean areas,and the sea areas with significant changes in gravity characteristics have higher matching accuracy,otherwise the accuracy is lower.On the basis of adaptability evaluation,planning the navigation path can help improve the feasibility of the operation task and reasonably avoid unfavorable factors.In this paper,the standard deviation,roughness and other characteristic parameters of gravity anomalies are used to evaluate the adaptability of the sea area's gravity field,and a reference map of the gravity field adapting grid is formed.The A^* algorithm is introduced to plan path between starting point and target point,so as to effectively avoid the non-fitting area and improve path's rationality. The problem of the traditional A^* algorithm is that there are too many broken lines in the planned route and the total curvature of the route is large.This paper designs an improved method,in which through the comparison analysis of the forward and backward directions and the screening of individual route nodes by node,the redundant course adjustment is effectively reduced and the path is smoothly optimized.