Fahad Muhammad, Guo Yi, Bingham Brian
Robotics and Automation Laboratory, Department of Electrical and Computer Engineering, Stevens Institute of Technology, Hoboken, NJ, United States.
Department of Mechanical and Aerospace Engineering, Naval Postgraduate School, Monterey, CA, United States.
Front Robot AI. 2018 May 28;5:52. doi: 10.3389/frobt.2018.00052. eCollection 2018.
Marine plumes exhibit characteristics such as intermittency, sinuous structure, shape and flow field coherency, and a time varying concentration profile. Due to the lack of experimental quantification of these characteristics for marine plumes, existing work often assumes marine plumes exhibit behavior similar to aerial plumes and are commonly modeled by filament based Lagrangian models. Our previous field experiments with Rhodamine dye plumes at Makai Research Pier at Oahu, Hawaii revealed that marine plumes show similar characteristics to aerial plumes qualitatively, but quantitatively they are disparate. Based on the field data collected, this paper presents a calibrated Eulerian plume model that exhibits the qualitative and quantitative characteristics exhibited by experimentally generated marine plumes. We propose a modified model with an intermittent source, and implement it in a Robot Operating System (ROS) based simulator. Concentration time series of stationary sampling points and dynamic sampling points across cross-sections and plume fronts are collected and analyzed for statistical parameters of the simulated plume. These parameters are then compared with statistical parameters from experimentally generated plumes. The comparison validates that the simulated plumes exhibit fine-scale qualitative and quantitative characteristics similar to experimental plumes. The ROS plume simulator facilitates future evaluations of environmental monitoring strategies by marine robots, and is made available for community use.
海洋羽流具有间歇性、蜿蜒结构、形状和流场连贯性以及随时间变化的浓度分布等特征。由于缺乏对海洋羽流这些特征的实验量化，现有工作通常假定海洋羽流表现出与空中羽流相似的行为，并且通常由基于细丝的拉格朗日模型进行模拟。我们之前在夏威夷瓦胡岛的马凯研究码头对罗丹明染料羽流进行的现场实验表明，海洋羽流在定性上与空中羽流表现出相似的特征，但在定量上却有所不同。基于收集到的现场数据，本文提出了一种经过校准的欧拉羽流模型，该模型展现出实验产生的海洋羽流所具有的定性和定量特征。我们提出了一个具有间歇性源的改进模型，并在基于机器人操作系统（ROS）的模拟器中实现。收集并分析了固定采样点以及跨横截面和羽流前沿的动态采样点的浓度时间序列，以获取模拟羽流的统计参数。然后将这些参数与实验产生的羽流的统计参数进行比较。该比较验证了模拟羽流展现出与实验羽流相似的精细尺度定性和定量特征。ROS羽流模拟器有助于未来对海洋机器人环境监测策略的评估，并可供社区使用。
