Node localization is one of the key technologies of Underwater Sensor Networks (UWSN). Because of the unique ocean environment conditions, beacon nodes are difficult to deploy precisely and move under the action of ocean currents and tides. Usually the beacon nodes are fixed to the sea floor through anchors and cables, and they can move within a certain range. Most existing localization algorithms do not take such mobility of beacon nodes into account, resulting in large localization errors. In order to overcome this disadvantage, this paper analyzes the characteristics of mobile-constrained beacon nodes and proposes a new localization algorithm in UWSN, namely, Mobile-constrained beacon based localization algorithm. It solves the problem that the position of beacon node is dynamic and imprecise. The unknown node can be located by the geometric relationship between the position of the anchor and the moving radius of the beacon node. In the calculation process, the polygonal area is transformed into a rectangular area, and the three-dimensional (3D) space is mapped into a two-dimensional (2D) space, the calculation process is simplified, and the feasibility of the algorithm is improved. The algorithm can be used both for 2D and 3D localization. Experiment results show that the algorithm proposed in this paper improves the localization accuracy, reduces the error rate of network node location, and has good practicality.

节点定位是水下传感器网络（UWSN）的关键技术之一。由于独特的海洋环境条件，信标节点难以精确部署并在洋流和潮汐的作用下移动。通常，信标节点通过锚和电缆固定在海底，并且可以在一定范围内移动。大多数现有的定位算法都没有考虑到信标节点的这种移动性，从而导致较大的定位错误。为了克服这一缺点，本文分析了移动受限信标节点的特点，提出了一种新的UWSN定位算法，即基于移动受限信标的定位算法。解决了信标节点位置动态，不精确的问题。未知节点可以通过锚点的位置与信标节点的移动半径之间的几何关系来定位。在计算过程中，将多边形区域转换为矩形区域，将三维（3D）空间映射为二维（2D）空间，简化了计算过程，提高了算法的可行性。 。该算法可用于2D和3D定位。实验结果表明，该算法提高了定位精度，降低了网络节点定位的错误率，具有良好的实用性。将三维空间（3D）映射到二维空间（2D），简化了计算过程，提高了算法的可行性。该算法可用于2D和3D定位。实验结果表明，该算法提高了定位精度，降低了网络节点定位的错误率，具有良好的实用性。将三维空间（3D）映射到二维空间（2D），简化了计算过程，提高了算法的可行性。该算法可用于2D和3D定位。实验结果表明，该算法提高了定位精度，降低了网络节点定位的错误率，具有良好的实用性。