Active Classification: Theory and Application to Underwater Inspection

We discuss the problem in which an autonomous vehicle must classify an object based on multiple views. We focus on the active classification setting, where the vehicle controls which views to select to best perform the classification. The problem is formulated as an extension to Bayesian active learning, and we show connections to recent theoretical guarantees in this area. We formally analyze the benefit of acting adaptively as new information becomes available. The analysis leads to a probabilistic algorithm for determining the best views to observe based on information theoretic costs. We validate our approach in two ways, both related to underwater inspection: 3D polyhedra recognition in synthetic depth maps and ship hull inspection with imaging sonar. These tasks encompass both the planning and recognition aspects of the active classification problem. The results demonstrate that actively planning for informative views can reduce the number of necessary views by up to 80% when compared to passive methods.Comment: 16 page

DESIGNING AN ROV FOR UNDERWATER INSPECTION

Design and construct a remotely operated vehicle (ROV) which fitted with three thrusters, a video transmission and a control system for the manoeuvrability is the main target of this project. This ROV is made up from aluminium frame and water proof enclosure to protect the controller system. Besides, this project also develop a closed loop system for auto depth function. This auto depth function is very important to make sure that the ROV is always at the desired depth. In addition, this ROV is also equipped with on board power to avoid the voltage drop along tether. The scope of studies for this project divided into two which are electrical and mechanical part. For the electrical part, the best controller circuit design need to be designed to ensure it gives the best manoeuvrability. Meanwhile, for mechanical part, the frame of the ROV need to be designed based of few considerations

IES an open system for underwater inspection

This paper describes the specification and design of a prototype of a low cost open system for the inspection of underwater structures based on a remotely operated underwater vehicle under the project IES, a 3 year long effort funded by the Portuguese R&D program Praxis XXI. Unlike commercial approaches, a modular open system characterised by the incorporation of an on-board computer allowing for advanced control capabilities is envisaged. The control console is based on a standard PC and the tether is used only for power delivery and to establish a simple communication channel. In this project, we use advanced hybrid control techniques for sophisticated semi-autonomous operation management and control. The control architecture reuses part of the one designed for the underwater vehicle Isurus operated by the Laboratory of Underwater Systems and Technologies of Porto University. The implementation is designed in order to allow for multiple sensor configurations specified as add-ins. This leads to a dynamic, scalable and flexible system that can be easily configured according to the user specifications

Underwater inspection using sonar-based volumetric submaps

We propose a submap-based technique for mapping of underwater structures with complex geometries. Our approach relies on the use of probabilistic volumetric techniques to create submaps from multibeam sonar scans, as these offer increased outlier robustness. Special attention is paid to the problem of denoising/enhancing sonar data. Pairwise submap alignment constraints are used in a factor graph framework to correct for navigation drift and improve map accuracy. We provide experimental results obtained from the inspection of the running gear and bulbous bow of a 600-foot, Wright-class supply ship.United States. Office of Naval Research (N00014-12-1-0093)United States. Office of Naval Research (N00014-14-1-0373

RAO-II: an AUV for underwater inspection

AIRSUB is a research project funded by the Spanish Ministry of Science and Technology whose aim is to explore the industrial applications of underwater robots. The Systems, Robotics and Vision Group (SRV) from the University of the Balearic Islands (UIB) is responsible for the subproject of cable/pipeline inspection [1]. To this purpose, an Autonomous Underwater Vehicle (AUV) is under development as a platform to test the vision algorithms, control strategies and software architectures devised in the last years. This paper describes the main characteristics of the new platform, which is based on a commercial Remotely Operated Vehicle (ROV). The original vehicle has been deeply modifi ed in structure as well as in its electric, electronic and sensorial facets to obtain fully autonomous operation

Quest and Probe Related to Erosion in the Wrap-Around of an Embankment

CESP\u27s divers team found several basalt blocks scattered on the stilling basin of a power plant. Water flowing through bottom outlets was initially supposed to cause erosion in the upstream rip-rap of the wrap-around. Events chronologically reported are: Underwater inspection; removal of materials; monitoring devices behavior; hydraulic tests. Hinder analyses led to recognition of misunderstanding on anomalous mechanism and misconception on the actual sources for the hauled rubbish

Active planning for underwater inspection and the benefit of adaptivity

We discuss the problem of inspecting an underwater structure, such as a submerged ship hull, with an autonomous underwater vehicle (AUV). Unlike a large body of prior work, we focus on planning the views of the AUV to improve the quality of the inspection, rather than maximizing the accuracy of a given data stream. We formulate the inspection planning problem as an extension to Bayesian active learning, and we show connections to recent theoretical guarantees in this area. We rigorously analyze the benefit of adaptive re-planning for such problems, and we prove that the potential benefit of adaptivity can be reduced from an exponential to a constant factor by changing the problem from cost minimization with a constraint on information gain to variance reduction with a constraint on cost. Such analysis allows the use of robust, non-adaptive planning algorithms that perform competitively with adaptive algorithms. Based on our analysis, we propose a method for constructing 3D meshes from sonar-derived point clouds, and we introduce uncertainty modeling through non-parametric Bayesian regression. Finally, we demonstrate the benefit of active inspection planning using sonar data from ship hull inspections with the Bluefin-MIT Hovering AUV.United States. Office of Naval Research (ONR Grant N00014-09-1-0700)United States. Office of Naval Research (ONR Grant N00014-07-1-00738)National Science Foundation (U.S.) (NSF grant 0831728)National Science Foundation (U.S.) (NSF grant CCR-0120778)National Science Foundation (U.S.) (NSF grant CNS-1035866

Pride of the South: Risk Analysis for Marine Biosecurity in Fiordland

This paper describes a model used to assess alternative scenarios for managing the marine biosecurity risk to Fiordland from vessel traffic. Scenarios are assessed in terms of risk reduction per dollar spent. To keep the analysis manageable, we focus on vessel risks from hull fouling, as this is considered the primary pathway of vessel-related spread. Our analysis includes evaluation of the costs and benefits of different types of vector treatment as well as the possibility of continued vessel monitoring and control of pest populations in Bluff Harbour to reduce the risk of vector infection.Fiordland, marine biosecurity, risk reduction, benefit cost analysis, management options, Bluff, Agricultural and Food Policy, Environmental Economics and Policy, Food Security and Poverty, Health Economics and Policy, Land Economics/Use, Livestock Production/Industries, Research Methods/ Statistical Methods,

Seabed Surveillance and Underwater Structures Inspection with Remotely Operated Vehicle − Power Ray

The marine ecosystem is necessary to be monitored as it is exposed to externalities and pollutants that affect biodiversity and the state of the underwater structures. There is a demand for a better, more dynamic, and safe monitoring approach to underwater research and inspection. The unmanned underwater vehicles are becoming a reachable and intuitive tool for underwater inspection, such as for the inspection of the marine hull of vessels, bridges, foundations, piers, pylons, and other support structures in ports. The main advantage of the use of the remotely operated underwater drone is cost and time-efficiency, as they allow to obtain information in a fast and safe way in real-time. In this paper we investigate the possibility of the use of a remotely operated underwater drone Power Ray for seabed observation and underwater structures inspection. It describes the re-sults of the field research collected from the use of low-cost underwater drone Power Ray. The data collected with an underwater drone presents footages of different underwater structures and areas in order to document the seabed state and underwater structures. Additionally, this article provides an overview of the problems in underwater inspection and monitoring, and possibilities offered by remotely operated vehicle Power Ray in solv-ing them. The results of the paper are not unique to working with a low-cost drone, but are illustrative of the challenges and problems that new users are likely to encounter when using this technology