Ministry of Earth Sciences, National Institute of Ocean Technology, Chennai, India.
Sci Rep. 2024 Aug 20;14(1):19266. doi: 10.1038/s41598-024-70158-3.
Descend and ascend of deep-water human-occupied submersibles based on buoyancy changes are enabled using a denomination of dispensable drop-weights, and loss of buoyancy are managed using emergency drop-weights and jettisoning identified systems. Failing to release the drop weights or jettison results in submersible stranding on the sea floor, leads to emergency recovery, and hence the drop-weight configuration has to be highly reliable. The paper, for the first time, based on hydrostatic stability, descend/ascend velocity needs, ocean salinity profile and loss-of-buoyancy situations, proposes a novel on-demand reliability based methodology for determining the safe drop-weight configuration and degradation-based mission abort strategy for deep-ocean human submersibles. Probabilistic on-demand reliability analysis based on IEC61508 standards for safety-critical systems using component field-failure data is carried out and the drop-weight configuration essential to meet the human-rated safety integrity level 3 during all stages of the subsea mission is identified for the deep-ocean human scientific submersible Matsya6000, based on which a mission abort protocol is evolved.
基于浮力变化的深潜载人潜水器的下潜和上浮是通过使用可抛弃压载物来实现的，而浮力损失则通过紧急抛弃压载物和抛弃已识别系统来管理。如果未能释放压载物或抛弃系统，潜水器就会被困在海底，导致紧急回收，因此压载物配置必须高度可靠。本文首次基于静水稳定性、下潜/上浮速度需求、海洋盐度剖面和失稳情况，提出了一种新的按需可靠性方法，用于确定深海载人潜水器的安全压载物配置和基于降级的任务中止策略。使用组件现场故障数据，根据 IEC61508 标准对安全关键系统进行概率按需可靠性分析，并确定深海载人科学潜水器 Matsya6000 在海底任务的所有阶段都需要满足人员安全完整性等级 3 的关键压载物配置，在此基础上制定了任务中止协议。
