水下基于层级的约束加权最小二乘时差定位

针对距离无关定位算法与距离相关定位算法中定位精度的问题，分析了误差对定位性能的影响及影响误差的因素，在最小二乘定位算法的基础上，提出了一种基于层级结构的约束加权最小二乘时差定位算法。该算法利用AUV( Autonomous Underwater Vehicle)对水下节点进行分层，使得具有层级和深度信息的信标节点升降至未知节点所在平面，从而将三维定位转换为二维定位，降低了算法的复杂度，同时避免了距离未知节点较远的信标节点对定位的影响，提高了测距精度，使定位误差进一步降低。仿真结果表明，该算法在位置误差较小的情况下，可以明显地提高定位精度。

The Constraint Weighted Least-Squares Algorithm of TDOA Based on Hierarchy in Underwater Sensor Wireless Network

With reference to the position accuracy in range￣based and range￣free location algorithm,we analyze error effect on the performance of localization and factors that influence the error. On the basis of least squares algorithm,we propose on the constraints of the weighted least squares algorithm of TDOA based on hierarchy. The algorithm u￣sing the AUV( Autonomous Underwater Vehicle) to stratified of underwater nodes,making beacon nodes with hierar￣chy and depth of information of unknown nodes lift the plane,which will be converted from three￣dimensional posi￣tioning to two￣dimensional localization. It reduces the complexity of the algorithm,at the same time avoids the influ￣ence of the beacon nodes far from unknown nodes for positioning improves the ranging precision,to further reduce the positioning error. The simulation results show that the proposed algorithm under the condition of the position er￣ror is smaller,which can significantly improve the positioning accuracy.