Recently, ocean exploration has increased considerably through the use of autonomous underwater vehicles (AUV). A key enabling technology is the precision of the AUV navigation capability. In this paper, we focus on understanding the limitation of the AUV navigation system. That is, what are the observable error-states for different maneuvering types of the AUV? Since analyzing the performance ...

Autonomous underwater vehicles (AUVs) are used increasingly to explore hazardous marine environments. Risk assessment for such complex systems is based on subjective judgment and expert knowledge as much as on hard statistics. Here, we describe the use of a risk management process tailored to AUV operations, the implementation of which requires the elicitation of expert judgment. We conducted a...

This paper presents a control synthesis methodology for a cubic AUV. The modeling part is based on CFD calculation and the control part is based on H∞ theory, nonlinear compensation, Smith compensation and Kalman filter. It is presented and adapted to Ciscrea AUV for heading control. A comparison with PID controller is given with simulations and sea tests.

This paper proposes novel cooperative navigation solutions for an Intervention Autonomous Underwater Vehicle (I-AUV) working in tandem with an Autonomous Surface Craft (ASC). The I-AUV is assumed to be moving in the presence of constant unknown ocean currents, and aims to estimate its position relying on measurements of its range to the ASC. Two different scenarios are considered: in the first ...

Over the last decades, the problem of building Autonomous Underwater Vehicles (AUVs) for missions in partially unknown underwater environment continue to challenge researchers. Although the AUV technology has matured and commercial systems have appeared in the market, a generic yet robust AUV command and control system still remains a key research focus. This thesis presents a novel command and...

BACKGROUND Urethral valves are infravesical congenital anomalies, with the posterior urethral valve (PUV) being the most prevalent one. Anterior urethral valve (AUV) is a rare but a well-known congenital anomaly. AUV and diverticula can cause severe obstruction, whose repercussions on the proximal urinary system can be important. Few cases have been described; both separately and in association...

Various forms of Autonomous Underwater Vehicles (AUVs) have evolved to solve different subsea mission requirements, these can be loosely grouped into two types: torpedo style AUVs and hovering AUVs. Torpedo AUVs were initially developed to be launched from torpedo tubes and consequently resemble torpedoes with a propeller and control surfaces at the rear, these vehicles have poor slow speed man...

In this paper, a tracking controller is proposed to navigate the autonomous underwater vehicle (AUV) within a specific region with known constant input delay. The unit quaternion representation is used for attitude control to avoid singularity problem encountered with Euler Angles. However, compensation of actuator delay is a challenging problem to handle with the nonlinear dynamics of an AUV. ...

One of the challenges for model prediction and validation is providing them with data of appropriate spatial and temporal resolution. The maturation and increased application of autonomous underwater vehicles (AUVs) in aquatic environments allows systematic data collection on these model-relevant scales. The goal of this study was to apply a fine-scale circulation and transport model (Delft3D) ...

In September 2007 on RRS Discovery, the Autosub6000 Autonomous Underwater Vehicle (AUV) completed its first deep water engineering trials, and less than a year later, fitted with a multibeam bathymetric mapping sonar, carried out its first science missions, as part of a geology and geophysics science cruise onboard the RRS James Cook to investigate potential geo-hazards (such as tsunami generat...