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1.
Maintaining a fixed position near the sea floor is a critical capability during the deployment of remotely operated or intelligent (autonomous) undersea vehicles in a variety of missions, including inspection and repair of undersea structures, data collection, and surveillance. We present an automatic optical station-keeping system for application to submersible vehicles in deep waters by exploiting the information in sea floor images. Readily measurable spatio-temporal image gradients are used to detect and compute the vehicle's translational and yaw motions using a direct motion vision technique. The vision system has been implemented on a Windows-NT Pentium platform, and the estimated positions and yaw angles are communicated via a serial link to the control system, running on a PC-386. Accurate station-keeping is demonstrated in experiments with a three-thruster floating vehicle in a 6-ft×12-ft×6-ft water tank 相似文献
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The purpose of this paper is to describe the status and general faunal composition of sponge reefs in the Georgia Basin (GB), British Columbia, Canada. Fourteen distinct deep-water glass sponge (Hexactinellid) reefs have been mapped using multibeam bathymetry and sidescan sonar in the GB. Seven of these have been surveyed visually using video from remotely operated vehicles (ROVs). Analysis of video data indicated that three reefs were undamaged, two were damaged and the other two were damaged but potentially recovering. The nature of the damaged reefs, with large areas of scattered dead sponge skeleton fragments and few live reef-building sponges (Aphrocallistes vastus and Heterochone calyx), as well as video evidence of tracks suggest they were damaged mechanically by mobile fishing gear.Relative abundance of the megafauna associated with the reefs is discussed in the context of oceanographic conditions, such as sediment accumulation and organic flux, as well as overall reef status. Of particular interest for fisheries conservation efforts in the area was the fact that one undamaged reef in the southern GB showed higher taxonomic richness and abundance of rockfish (Sebastes spp.), both adult and juvenile, compared to an adjacent damaged reef. This result suggests that undamaged reefs may act as refugia for these endangered stocks. 相似文献
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《Oceanic Engineering, IEEE Journal of》1994,19(2):175-182
Navigation of an underwater minefield by a remotely operated vehicle (ROV) or an autonomous undersea vehicle (AUV) requires the detection, localization, and avoidance of obstacles. The sizes of obstacles to be avoided range from the diameter of cables up to the size of other vehicles. A classical solution to this problem is the use of an obstacle avoidance sonar, but due to the high degree of sophistication of modern-day mines and unfriendly vehicles, it is desirable to avoid signal energies that might be detectable. The use of spread-spectrum signal structures is one possible way to avoid this difficulty while retaining the capability of despreading the energy at the receiver. This paper presents the development of a beamforming system that uses a frequency-decomposition FFT beamformer and a spread-spectrum signal structure for low-probability-of-detection navigation 相似文献
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Many underwater intervention tasks are today performed using manned submersibles or remotely operated vehicles in teleoperation mode. Autonomous underwater vehicles are mostly employed in survey applications. In fact, the low bandwidth and significant time delay inherent in acoustic subsea communications represent a considerable obstacle to remotely operate a manipulation system, making it impossible for remote controllers to react to problems in a timely manner.Nevertheless, vehicles with no physical link and with no human occupants permit intervention in dangerous areas, such as in deep ocean, under ice, in missions to retrieve hazardous objects, or in classified areas. The key element in underwater intervention performed with autonomous vehicles is autonomous manipulation. This is a challenging technology milestone, which refers to the capability of a robot system that performs intervention tasks requiring physical contacts with unstructured environments without continuous human supervision.Today, only few AUVs are equipped with manipulators. SAUVIM (Semi Autonomous Underwater Vehicle for Intervention Mission, University of Hawaii) is one of the first underwater vehicle capable of autonomous manipulation.This paper presents the solutions chosen within the development of the system in order to address the problems intrinsic to autonomous underwater manipulation. In the proposed approach, the most noticeable aspect is the increase in the level of information transferred between the system and the human supervisor.We describe one of the first trials of autonomous intervention performed by SAUVIM in the oceanic environment. To the best knowledge of the authors, no sea trials in underwater autonomous manipulation have been presented in the literature. The presented operation is an underwater recovery mission, which consists in a sequence of autonomous tasks finalized to search for the target and to securely hook a cable to it in order to bring the target to the surface. 相似文献
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D. Van Rooij L. De Mol E. Le Guilloux M. Wisshak V.A.I. Huvenne R. Moeremans J.-P. Henriet 《Deep Sea Research Part I: Oceanographic Research Papers》2010,57(12):1561-1572
We report the northernmost and deepest known occurrence of deep-water pycnodontine oysters, based on two surveys along the French Atlantic continental margin to the La Chapelle continental slope (2006) and the Guilvinec Canyon (2008). The combined use of multibeam bathymetry, seismic profiling, CTD casts and a remotely operated vehicle (ROV) made it possible to describe the physical habitat and to assess the oceanographic control for the recently described species Neopycnodonte zibrowii. These oysters have been observed in vivo in depths from 540 to 846 m, colonizing overhanging banks or escarpments protruding from steep canyon flanks. Especially in the Bay of Biscay, such physical habitats may only be observed within canyons, where they are created by both long-term turbiditic and contouritic processes. Frequent observations of sand ripples on the seabed indicate the presence of a steady, but enhanced bottom current of about 40 cm/s. The occurrence of oysters also coincides with the interface between the Eastern North Atlantic Water and the Mediterranean Outflow Water. A combination of this water mass mixing, internal tide generation and a strong primary surface productivity may generate an enhanced nutrient flux, which is funnelled through the canyon. When the ideal environmental conditions are met, up to 100 individuals per m² may be observed. These deep-water oysters require a vertical habitat, which is often incompatible with the requirements of other sessile organisms, and are only sparsely distributed along the continental margins. The discovery of these giant oyster banks illustrates the rich biodiversity of deep-sea canyons and their underestimation as true ecosystem hotspots. 相似文献
7.
Segmentation methods for visual tracking of deep-ocean jellyfish using a conventional camera 总被引：1，自引：0，他引：1
This paper presents a vision algorithm that enables automated jellyfish tracking using remotely operated vehicles (ROVs) or autonomous underwater vehicles (AUVs). The discussion focuses on algorithm design. The introduction provides a novel performance-assessment tool, called segmentation efficiency, which aids in matching potential vision algorithms to the jelly-tracking task. This general-purpose tool evaluates the inherent applicability of various algorithms to particular tracking applications. This tool is applied to the problem of tracking transparent jellyfish under uneven time-varying illumination in particle-filled scenes. The result is the selection of a fixed-gradient threshold-based vision algorithm. This approach, implemented as part of a pilot aid for the Monterey Bay Aquarium Research Institute's ROV Ventana, has demonstrated automated jelly tracking for as long as 89 min. 相似文献
8.
Massimo Caccia 《Oceanic Engineering, IEEE Journal of》2006,31(3):711-727
A laser-triangulation optical-correlation sensor for estimating the motion of underwater vehicles at low speed in the proximity of the seabed is described. Experimental results, obtained by processing image sequences acquired by the instrument mounted below the Romeo remotely operated vehicle (ROV) in operating conditions, are presented 相似文献
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This paper reports the development and experimental evaluation of two in situ least squares techniques for estimating the alignment matrix of Doppler sonars commonly used for precision navigation of oceanographic submersibles. Most previously reported methods addressed the problem of single degree-of-freedom heading alignment using bottom-lock Doppler sonar data and global positioning system (GPS) navigation data. This paper reports and evaluates two techniques for three degree-of-freedom calibration of attitude and Doppler sonar sensors using sensor data available to vehicles at full ocean depth. The first technique provides a general linear least squares estimate of the alignment matrix. The second technique results in a least squares alignment matrix estimate constrained to the group of rotation matrices. The performance of these estimates is evaluated with a laboratory remotely operated vehicle (ROV) and a field-deployed autonomous underwater vehicle (AUV). Experimental results are reported which demonstrate that Doppler navigation employing the reported alignment calibration techniques significantly improves navigation precision. The experiments show that the latter technique provides calibration estimates that improve Doppler navigation precision not only on the calibration data set itself, but also provide improved precision over a wide variety of vehicle trajectories other than the calibration data set. 相似文献
11.
Ship hulls, as well as bridges, port dock pilings, dams, and various underwater structures need to be inspected for periodic maintenance. Additionally, there is a critical need to provide protection against sabotage activities, and to establish effective countermeasures against illegal smuggling activities. Unmanned underwater vehicles are suitable platforms for the development of automated inspection systems, but require integration with appropriate sensor technologies. This paper describes a vision system for automated ship-hull inspection, based on computing the necessary information for positioning, navigation, and mapping of the hull from stereo images. Binocular cues are critical in resolving a number of complex visual artifacts that hamper monocular vision in shallow-water conditions. Furthermore, they simplify the estimation of vehicle pose and motion, which is fundamental for successful automatic operation. The system has been implemented on a commercial remotely operated vehicle (ROV), and tested in pool and dock tests. Results from various trials are presented to demonstrate the system capabilities 相似文献
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The application of a neural network controller to remotely operated vehicles (ROVs) is described. Three learning algorithms for online implementation of a neural net controller are discussed with a critic equation. These control schemes do not require any information about the system dynamics except an estimate of the inertia terms. Selection of the number of layers in the neural network, the number of neurons in the hidden layer, initial weights for the network and the critic coefficient were done based on the results of preliminary tests. The performances of the three learning algorithms were compared by computer simulation. The effectiveness of the neural net controller in handling time-varying parameters and random noise is shown by a case study of the ROV system 相似文献
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A prototype supervisory control system for a remotely operated vehicle (ROV) is described and several key elements demonstrated in simulation and in-water tests. This system is specifically designed to fill the needs of JASON, a new ROV under development that will perform scientific tasks on the seafloor to depths of 6000 m. JASON will operate from the ARGO towed imaging platform, which is currently operational. Supervisory control is a paradigm for combined human and computer control. Several key elements of the supervisory control system are presented. These include the closed-loop positioning system based on a high-resolution acoustic navigation system, a monitoring capability for assessing performance and detecting undesirable changes, and an interface that allows the human operator and the computer system to specify the desired vehicle trajectory jointly. 相似文献
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随着海洋调查技术的发展和海洋研究的深入,基于深潜器平台的近海底调查在海洋调查与研究中的综合应用日趋常态。基于这一背景,本文介绍了搭载于"发现"号缆控水下机器人(remotely operatedvehicle,ROV)的近海底综合声学调查系统及其在台西南冷泉区的应用实例。基于"发现"号ROV平台的近海底综合声学调查系统主要由R2Sonic2024多波束测深系统,模块一体化的侧扫声纳-浅地层剖面系统和水下综合定位与导航系统构成。该系统的配置极大地扩展和完善了"发现"号ROV的近海底调查能力,实现了近海底多波束、侧扫和浅剖等声学数据的同步采集和快速融合处理。基于本套系统在南海冷泉区的综合应用,本文对其工作流程进行了介绍,并对所获得一系列成果进行了初步分析。结果表明,近海底综合探测系统的应用为南海冷泉区的识别、海底地形地貌特征分析以及空间规模量化研究等内容提供了不可或缺的基础资料。本套系统的配置和成功应用,有效地提高了我国的近海底调查和作业能力。 相似文献
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深海遥控潜水器多体系统非线性耦合动力特性模拟 总被引：1，自引：0，他引：1
建立带缆遥控潜水器(TROV)系统空间运动模型,探讨支持船-吊缆-中际站-脐带缆-潜水器多体之间的强非线性耦合运动机理。潜器的运动考虑为六自由度,缆索分段的三维动态方程中采用了"凝集参数"模型与平均切向量非线性流体动力载荷处理技术,通过计算非均匀缆索的动张力和瞬态构型,预报导致脐带缆保护层及其内部光电传输芯线结构破坏的巨大瞬间突变载荷,对避免谐振,延长缆索寿命和最大限度地扩大ROV系统安全操作的范围,确保潜水器安全入坞和回收,节约试验费,避免作业事故都具有重要意义。 相似文献
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法向承力锚(VLA)--一种适用于深海工程的新型系泊基础 总被引：2，自引：0，他引：2
深水系泊基础是深水系泊系统的重要组成,随着海洋油气资源开发的加速发展,深水系泊系统的关键技术成为国际海洋油气资源开发的重要研究领域.法向承力锚（VLA）是一种崭新的适用于深海油气资源开发的系泊基础形式,论文对其应用、性能特点、工作原理、安装与回收以及计算分析方法等进行了全面介绍,以期对科研人员进一步认识深水系泊系统的关键技术有所帮助,并对国内深水系泊系统的研发起到一定的借鉴作用. 相似文献
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Charles K. Paull William R. Normark William Ussler III David W. Caress Rendy Keaten 《Marine Geology》2008,250(3-4):258-275
Seafloor blister-like mounds, methane migration and gas hydrate formation were investigated through detailed seafloor surveys in Santa Monica Basin, offshore of Los Angeles, California. Two distinct deep-water (≥ 800 m water depth) topographic mounds were surveyed using an autonomous underwater vehicle (carrying a multibeam sonar and a chirp sub-bottom profiler) and one of these was explored with the remotely operated vehicle Tiburon. The mounds are > 10 m high and > 100 m wide dome-shaped bathymetric features. These mounds protrude from crests of broad anticlines (~ 20 m high and 1 to 3 km long) formed within latest Quaternary-aged seafloor sediment associated with compression between lateral offsets in regional faults. No allochthonous sediments were observed on the mounds, except slumped material off the steep slopes of the mounds. Continuous streams of methane gas bubbles emanate from the crest of the northeastern mound, and extensive methane-derived authigenic carbonate pavements and chemosynthetic communities mantle the mound surface. The large local vertical displacements needed to produce these mounds suggests a corresponding net mass accumulation has occurred within the immediate subsurface. Formation and accumulation of pure gas hydrate lenses in the subsurface is proposed as a mechanism to blister the seafloor and form these mounds. 相似文献
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A deep ROV "DOLPHIN 3K": Design and performance analysis 总被引：1，自引：0，他引：1
DOLPHIN 3K is a tethered remotely operated vehicle (ROV) system for ocean bottom surveys down to a depth of 3300 m. The system will be completed in fiscal year 1986. This paper describes the design of the system, and analyzes the maneuverability of the vehicle and the transmission performance of the optical fiber data communication system. 相似文献
20.
As the soil traction of the track system consisting of a track plate and protruded grousers is generally higher than that of a comparable wheel system, underwater tracked vehicles are the favored platforms for heavy-weight remotely operated vehicles (ROVs). When an underwater tracked vehicle moves on the seafloor, the track system laterally transmits an engine torque to the soil-track interface, resulting in slip displacement and an associated soil thrust acting as a traction force. Therefore, to evaluate the mobility of underwater tracked vehicle, it is critical to evaluate the soil thrust of the track system based on the soil-track interaction. Unlike the soil thrust of sandy soils, a reliable soil thrust assessment method accounting for the failure mechanism of clayey soil has yet to be developed in spite of its significance. An experimental study on the mechanism of the soil thrust of clayey soil was thus performed. Model track experiments were conducted on a model track system with clayey soil. Based on the experiment results, the mechanism of the soil thrust of clayey soil was investigated and was compared with the mechanism of soil thrust derived from the previous soil thrust assessment methods using sandy soil. Particular attention was given to the development of a new soil thrust prediction model for the track system on clayey soil using the limit equilibrium analysis technique. 相似文献