In this paper, we investigate the mobile node localization problem in an underwater positioning system using multiple surface beacons, where time synchronization between the surface beacons and underwater mobile nodes is not required. First, we propose a Time-Difference-of-Arrival-based (TDoA-based) node localization method. In the proposed method, as the underwater node receives the positioning messages from more than or equal to three surface beacons belonging to the same grid at one epoch, it calculates the location by itself using the information of received positioning messages and the corresponding arrival times. To deal with the problem that the number of received positioning messages at one epoch by the underwater node is not enough for the location calculation, we present the modified TDoA- based node localization method with buffered messages and the modified TDoA-based node localization method with motion information. The effectiveness of proposed TDoA-based node localization method and two modified methods is validated by simulation results and sea experiment data analytical results. The robustness of the TDoA-based node localization method is improved by two modified methods. Moreover, using the proposed TDoA-based node localization method and two modified methods, the underwater node can localize itself in low energy consumption and passive mode.

中文翻译：

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多表面信标的水下移动节点基于到达时间差异的定位方法

在本文中，我们研究了使用多个水面信标的水下定位系统中的移动节点定位问题，其中不需要水面信标与水下移动节点之间的时间同步。首先，我们提出了一种基于到达时间差（TDOA）的节点定位方法。在所提出的方法中，由于水下节点在一个时期从属于同一网格的三个以上信标接收到定位消息，因此它使用接收到的定位消息的信息和相应的到达时间自行计算位置。为了解决水下节点在一个时期接收到的定位消息数量不足以进行位置计算的问题，我们提出了带有缓冲消息的改进的基于TDoA的节点定位方法和具有运动信息的改进的基于TDoA的节点定位方法。仿真结果和海上实验数据分析结果验证了所提出的基于TDoA的节点定位方法和两种改进方法的有效性。通过两种改进的方法提高了基于TDoA的节点定位方法的鲁棒性。此外，使用所提出的基于TDoA的节点定位方法和两种改进的方法，水下节点可以以低能耗和被动模式进行自身定位。通过两种改进的方法提高了基于TDoA的节点定位方法的鲁棒性。此外，使用所提出的基于TDoA的节点定位方法和两种改进的方法，水下节点可以以低能耗和被动模式进行自身定位。通过两种改进的方法提高了基于TDoA的节点定位方法的鲁棒性。此外，使用所提出的基于TDoA的节点定位方法和两种改进的方法，水下节点可以以低能耗和被动模式进行自身定位。