深海爬游机器人概念及关键技术分析

  目的  针对可潜浮式沉积物捕获器（FST）的时变姿态会影响采样效率的问题，对全采样流程内FST的质心偏移规律及姿态角变化进行定量分析与评估。  方法  设计一种包含采样模块及浮力调节模块的FST，然后利用SolidWorks软件进行建模，建立坐标系；通过Matlab软件完成静力学分析，模拟得到全流程内各时刻FST质心相对于坐标原点的偏移量；基于力矩平衡公式，推导因质心偏移造成的机体姿态变化；运用平面射影定理，定量分析姿态变化对有效采集面积的影响。  结果  结果显示，质心偏移被限制在以载体坐标系原点为圆心、半径为$ 8 times {10^{ - 3}};{text{m}} $的圆内，质心坐标域为${x_{text{g}}} in ( - 6 times {10^{ - 3}};{text{m}}, 3 times {10^{ - 3}};{text{m}})$，${y_{text{g}}} in ( - 1 times {10^{ - 3}};{text{m}}, $ 7 times {10^{ - 3}};{text{m}})$；姿态角变化域为俯仰角$ theta in ( - 1.5^circ , 16.6^circ ) $，横滚角$phi in ( - {2.6^ circ }, {16.8^ circ })$；当$ theta = 14.7^circ , phi {text{ = 13}}^circ $时，有效采集面积缩减为捕获装置面积的94.27%，为最小值，当其他条件相同时，捕获相同质量的沉降颗粒所需时间比100%实采面积所需捕获时间多0.0578倍。  结论  研究工作可为FST的稳性分析和浮力调节系统设计提供有益的参考。

Estimating carbon,silica and diatom export from a naturally fertilised phytoplankton bloom in the Southern Ocean using PELAGRA: a novel drifting sediment trap

  Objectives  This study focuses on how the sampling efficiency of a free-diving sediment trap (FST) is affected by its body posture, and uses quantitative analysis to describe the changes of the center of gravity and attitude angles.   Methods  An FST is designed which consists of a sampling module and a buoyancy control system. A 3D model of the FST is built using SolidWorks. Kinematic analysis is completed using Matlab, and the offset of the center of gravity at each moment in the whole working cycle is obtained by simulation. The principle of moments is used to derive its attitude changes caused by the offset of the center of gravity. The influence of the attitude changes on the effective collection area is then quantitatively analyzed using projective transformation.   Results  The result shows that the offset of the center of gravity is limited to a circle with the origin of the body-fixed coordinate system as the center and a radius of $ 8 times {10^{ - 3}};{text{m}} $. It is seen that the domains of x and y are ${x_{text{g}}} in ( - 6 times {10^{ - 3}};{text{m}},{text{ }}3 times {10^{ - 3}};{text{m}})$, ${y_{text{g}}} in ( - 1 times {10^{ - 3}};{text{m}},{text{ }}7 times {10^{ - 3}};{text{m}})$, and the domains of the attitude angles are $ theta in ( - 1.5^circ ,{text{ }}16.6^circ ) $ and $phi in ( - {2.6^ circ },{16.8^ circ })$. When $theta = 14.7^circ {text{ and }}phi {text{ = 13}}^circ$, the effective collection area is reduced to 94.27% of the original value. Compared with the 100% effective collection area, it takes 1.06 times the original collection time to collect the same volume of sinking particles.   Conclusions  The results of this study can provide useful references for FST stability analysis and buoyancy regulation system design.