合作定位节点选择策略

合作定位是指接收机之间通过合作网络交换关键定位信息实现协同定位的新技术,接收机进行合作定位过程中可供使用的辅助节点包括可视卫星和已定位邻居接收机。接收机之间的合作增加定位过程中的可用辅助节点数量,进而增加位置估计的计算量和计算时间,在可用辅助节点较多时,定位实时性很难得到保证。提出改进次优节点选择算法,计算备选节点之间单位向量差作为节点价值,选择拥有最大价值的节点作为辅助节点。将新算法与4种典型的节点选择算法进行了对比,仿真实验证明该算法能够在较短时间内选择出接近最优算法得到的组合,综合性能优于现有节点选择算法。

Node selection algorithm in cooperative positioning

Cooperative Positioning is a new Positioning technology. The GNSS receivers share critical positioning information with each other by communication system. The receivers estimate their position with localized neighbor receivers and the satellites in view. The increasing of the nodes used for position estimation leads to more calculation, the receiver may fail to estimate their position in real-time. A new node selection algorithm called improved quosi-optimal algorithm is proposed. The node to be selected gets an importance value by calculating the unit node-node vectors, the one with the maximum importance value is selected in each iterate. The new algorithm is compared with four typical node selection algorithms. Computer simulation shows that the nodes selected by the proposed algorithm is very close to the ones selected by optimal algorithm, but with less time cost. The simulation result proved that the performance of the new algorithm is better than the typical node selection algorithm.