Autonomous Vehicles Design for Operation in Rough Seas

Technical Background

Underwater operations have become of primary importance in several fields of application in the marine and maritime sector, such as deep-sea oil drilling, offshore platform installation and rescue operations. This requires underwater vehicles to perform increasingly complex tasks in ever more daunting scenarios. More and more often the need arises for underwater vehicles to undertake interventions in dangerous scenarios, where the need to operate in deep and cluttered environments is unattainable by divers. In order to address these challenges, new breeds of robots are being developed. Standard underwater robots, commonly referred to as Unmanned Underwater Vehicles (UUVs), can be categorized into Autonomous Underwater Vehicles (AUVs) and Remotely Operated Vehicles (ROVs). While AUVs are more commonly employed for monitoring tasks over open stretches of sea, at present most intervention and maintenance operations are performed by ROVs.  

Despite their widespread employment in the offshore industry, UUVs are subject to major limitations associated with their bulk and lack of structural flexibility. The capability of this class of vehicles to operate at close proximity with submerged structures is often challenged by the difficulty to establish a safe interaction with the surrounding, especially when exposed to current or wave dominated climates. This is a common occurrence, for instance, in the installation and maintenance operations of marine renewable energy plants (see Elvander & Hawkes, 2012). 


Aims and Objectives

The aim of this project is to develop new technological solutions to effectively manage the problem of station keeping in the presence of wave and current disturbances. In order to facilitate the transition toward a fully autonomous management of marine renewable plants, it is of primary importance that new breeds of underwater vehicles are endowed with the tools to perform accurate station keeping at close quarter with submerged structures even in highly perturbed climate. For this purpose, two solutions are envisaged: a control-based approach and a mechanical-based approach. The former envisages the recourse to advance control techniques which aid the vehicle in compensating from weather disturbances by making use of predictive control. The latter is based on the implementation of new actuators which guarantee a higher degree of stability: these could be a purpose-designed manipulator which anchors the vehicle to a neighboring, submerged structure or a retrievable harpoon-like system which constrains the degrees of freedom of the vehicle. The candidate will have the freedom to pursue one of these paths as well as providing his/her own novel insight. 


References

  1. Elvander, J. & Hawkes, G. 2012 Rovs and auvs in support of marine renewable technologies. In MTS/IEEE Oceans 2012 , pp. 1–6. Hampton Roads, VA. 
  2. Daniel C. Fernández and Geoffrey A. Hollinger, 2017, Model Predictive Control for Underwater Robots in Ocean Waves, IEEE ROBOTICS AND AUTOMATION LETTERS, VOL. 2, NO. 1. 

Links to existing projects

  1. this project will be tightly linked to the large Orca-Hub consortium

Closing Date: 

Monday, December 31, 2018
Mission example of AUV surveillance near tidal turbine
Mission example of ROV manipulation near pile in waves
Flow modeling for Model Predictive Control of AUV in the wake of a pipeline

Principal Supervisor: 

Assistant Supervisor: 

Eligibility: 

Minimum entry qualification - an Honours degree at 2:1 or above (or International equivalent) in a relevant science or engineering discipline, possibly supported by an MSc Degree. Further information on English language requirements for EU/Overseas applicants.

Funding: