This paper presents a scalable acoustic navigation approach for the unified command, control and coordination of multiple autonomous underwater vehicles (AUVs). Existing multi-AUV operations typically achieve coordination manually, by programming individual vehicles on the surface via radio communications, which becomes impractical with large vehicle numbers; or they require bi-directional inter-vehicle acoustic communications to achieve limited coordination when submerged, with limited scalability due to the physical properties of the acoustic channel. Our approach utilizes a single, periodically-broadcasting beacon acting as a navigation reference for the group of AUVs, each of which carries a chip-scale atomic clock (CSAC) and fixed ultra-short baseline (USBL) array of acoustic receivers. One-way travel-time (OWTT) from synchronized clocks and time-delays between signals received by each array element allows any number of vehicles within receive distance to determine range, angle, and thus determine their relative position to the beacon. The operator can command different vehicle behaviors by selecting between broadcast signals from a predetermined set, while coordination between AUVs is achieved without inter-vehicle communication, by defining individual vehicle behaviors within the context of the group. Vehicle behaviors are designed within a beacon-centric moving frame of reference, allowing the operator to control the absolute position of the AUV group by re-positioning the navigation beacon to survey the area of interest. Multiple deployments with a fleet of three miniature, low-cost SandShark AUVs performing closed-loop acoustic navigation in real-time provide experimental results validated against a secondary long-baseline (LBL) positioning system, demonstrating the capabilities and robustness of our approach with real-world data.
翻译:本文为多自动水下车辆的统一指挥、控制和协调提供了可扩缩的声学导航方法。现有的多自动水下车辆行动通常通过无线电通信在地面上编程单个车辆,通过无线电通信实现手工协调,而无线电通信与大型车辆数目不切实际;或者它们需要双向车辆间声学通信,以便在潜水时实现有限的协调,由于声道的物理性质,可扩缩程度有限。我们的方法使用单一的定期播送信标,作为AUV小组的导航参考,每个小组都携带芯片级原子时钟和固定的超快基线声波接收器阵列。 单向旅行时间(OWTT),从同步时钟和每个阵列收到的信号之间的时间差,使任何在距离内的车辆能够确定射程、角度,从而确定其对信标的相对位置。操作者可以通过从预定的一组广播信号中选择不同的车辆行为,而AUV系统之间的协调则无需进行车际通信,通过确定每个车辆间间高层接收器的中级接收器基线,在AUV机队的绝对性轨道定位定位范围内定位上,使AU型的飞行定位的飞行定位能定位能定位定位能够显示AUL的精确定位的精确定位定位定位定位,使AUV机组的精确定位定位定位向AV的精确定位的定位定位定位向AUL的精确定位的定位定位定位定位向方向的定位定位定位向上。