An Active Contour For Underwater Target Tracking And Navigation.

This paper presents a vision based tracking system for routine underwater pipeline or cable inspection for autonomous underwater vehicles (AUV’s)

Underwater reconstruction using depth sensors

In this paper we describe experiments in which we acquire range images of underwater surfaces with four types of depth sensors and attempt to reconstruct underwater surfaces. Two conditions are tested: acquiring range images by submersing the sensors and by holding the sensors over the water line and recording through water. We found out that only the Kinect sensor is able to acquire depth images of submersed surfaces by holding the sensor above water. We compare the reconstructed underwater geometry with meshes obtained when the surfaces were not submersed. These findings show that 3D underwater reconstruction using depth sensors is possible, despite the high water absorption of the near infrared spectrum in which these sensors operate

Control of a compact, tetherless ROV for in-contact inspection of complex underwater structures

In this paper we present the dynamic modeling and control of EVIE (Ellipsoidal Vehicle for Inspection and Exploration), an underwater surface contact ROV (Remotely Operated Vehicle) for inspection and exploration. Underwater surface inspection is a challenging and hazardous task that demands sophisticated automation – as in boiling water nuclear reactors, water pipeline, submarine hull and oil pipelines inspection. EVIE is inspired by its predecessor, the Omni Submersible, in its ellipsoidal, streamlined, and appendage free shape. The objective for the robot is to carry inspection sensors – magnetic, acoustics or visual – to determine cracks on submerged surfaces. Unlike a robot moving in a practically boundless fluid, contact forces complicate the dynamics by bringing in normal and frictional forces, both of which are highly non linear in nature. This makes the modeling much more challenging and the development of an integrated controller more difficult. In this paper we will discuss the preliminary design and hydrodynamic modeling of such a robot. We analyze in detail the controls for one of the many transitional states of this robot. Eventually all transitional states need to be integrated to develop a hybrid dynamical system which shall use a controller that can adapt to its different states.Electric Power Research Institut

Hybrid control architecture for navigation of unmanned underwater vehicles

In the present paper, a hybrid architecture based on multi-agent systems is proposed based on a layered system. This architecture presents qualities of modularity and scalability. It is also developed a methodology for trajectory tracking based on the generation of a reliable virtual space, on which the navigation takes place under operative conditions (safety and e ectiveness). Time processing operations reduction is expected during the inspection

Guidance and control of an autonomous underwater vehicle

Merged with duplicate record 10026.1/856 on 07.03.2017 by CS (TIS)A cooperative project between the Universities of Plymouth and Cranfield was aimed at designing and developing an autonomous underwater vehicle named Hammerhead. The work presented herein is to formulate an advance guidance and control system and to implement it in the Hammerhead. This involves the description of Hammerhead hardware from a control system perspective. In addition to the control system, an intelligent navigation scheme and a state of the art vision system is also developed. However, the development of these submodules is out of the scope of this thesis. To model an underwater vehicle, the traditional way is to acquire painstaking mathematical models based on laws of physics and then simplify and linearise the models to some operating point. One of the principal novelties of this research is the use of system identification techniques on actual vehicle data obtained from full scale in water experiments. Two new guidance mechanisms have also been formulated for cruising type vehicles. The first is a modification of the proportional navigation guidance for missiles whilst the other is a hybrid law which is a combination of several guidance strategies employed during different phases of the Right. In addition to the modelling process and guidance systems, a number of robust control methodologies have been conceived for Hammerhead. A discrete time linear quadratic Gaussian with loop transfer recovery based autopilot is formulated and integrated with the conventional and more advance guidance laws proposed. A model predictive controller (MPC) has also been devised which is constructed using artificial intelligence techniques such as genetic algorithms (GA) and fuzzy logic. A GA is employed as an online optimization routine whilst fuzzy logic has been exploited as an objective function in an MPC framework. The GA-MPC autopilot has been implemented in Hammerhead in real time and results demonstrate excellent robustness despite the presence of disturbances and ever present modelling uncertainty. To the author's knowledge, this is the first successful application of a GA in real time optimization for controller tuning in the marine sector and thus the thesis makes an extremely novel and useful contribution to control system design in general. The controllers are also integrated with the proposed guidance laws and is also considered to be an invaluable contribution to knowledge. Moreover, the autopilots are used in conjunction with a vision based altitude information sensor and simulation results demonstrate the efficacy of the controllers to cope with uncertain altitude demands.J&S MARINE LTD., QINETIQ, SUBSEA 7 AND SOUTH WEST WATER PL

Advancing Climate Change Research and Hydrocarbon Leak Detection : by Combining Dissolved Carbon Dioxide and Methane Measurements with ADCP Data

With the emergence of largescale, comprehensive environmental monitoring projects, there is an increased need to combine state-of-the art technologies to address complicated problems such as ocean acidifi cation and hydrocarbon leak detection

Design and Estimation of an AUV Portable Intelligent Rescue System Based on Attitude Recognition Algorithm

This research is based on the attitude sensing algorithm to design a portable intelligent rescue system for autonomous underwater vehicles (AUVs). To lower the possibility of losing the underwater vehicle and reduce the difficulty of rescuing, when an AUV intelligent rescue system (AIRS) detects the fault of AUVs and they could not be reclaimed, AIRS can pump carbon dioxide into the airbag immediately to make the vehicle resurface. AIRS consists of attitude sensing module, double-trigger inflator mechanism, and activity recognition algorithm. The sensing module is an eleven-DOF sensor that is made up of a six-axis inertial sensor, a three-axis magnetometer, a barometer, and a thermometer. Furthermore, the signal calibration and extended Kalman filter (SC-EKF) is proposed to be used subsequently to calibrate and fuse the data from the sensing module. Then, the attitude data are classified with the principle of feature extraction (FE) and backpropagation network (BPN) classifier. Finally, the designed double-trigger inflator can be triggered not only by electricity but also by water damage when the waterproof cabin is severely broken. With the AIRS technology, the safety of detecting and investigating the use AUVs can be increased since there is no need to send divers to engage in the rescue mission under water

Physical Behaviours for Trust Assessment in Autonomous Underwater MANETs

This paper proposes a new approach to determine trust in resource-constrained networks of autonomous systems based on their physical behaviour, using the motion of nodes within a team to detect and identify malicious or failing operation within their cohort. This is accomplished by looking at operations in the underwater marine environment. We present a series of composite metrics based on physical movement, and apply these metrics to the detection and discrimination of sample physical misbehaviours. This approach opens the possibility of bringing information about both the physical and communications behaviours of autonomous MANETs together to strengthen and expand the application of future Trust Management Frameworks in sparse and/or resource constrained environment

Underwater Robots Part I: Current Systems and Problem Pose

International audienceThis paper constitutes the first part of a general overview of underwater robotics. The second part is titled: Underwater Robots Part II: existing solutions and open issues

Review of Autonomous Underwater Vehicles

The exploration of ocean space requires underwater vehicles (UV) such as submarines, autonomous underwater vehicles (AUV), manned underwater vehicles, remotely operated vehicles (ROV) and ship towed instrumentation packages. Of these, AUVs dominate the exploration of deep oceans. The list of applications where UVs can be employed include long-term deployments where they would serve as platforms for spatiotemporal samplings of physical characteristics (e.g., temperature, depth, conductivity, current) of the water column; use of multiple vehicles for mapping out an evolving phenomenon such as hydrothermal vents, tsunamis, etc., rapidly; transiting long distances to a site for making observations as part of a response team; search and mapping of seabed minerals; underwater warfare using submarines; and mine hunting, pipe laying, and inspection and maintenance of offshore structures