Design and Control of Bio-inspired Pulsed-jet Underwater Vehicles with augmented maneuverability

In the understanding of the ocean general circulation, a fundamental question still remains unanswered: what are the leading dissipative terms that regulate the overall dynamical balance of the ocean? (Naveira-Garabato, 2012). Momentum sinks are associated with prominent features of the bottom topography, as well as smaller-scale elements O(10 km) (Naveira-Garabato et al., 2012). These are systematically unresolved by conventional global topographic datasets and by the general circulation models regularly used to investigate ocean dynamics. The availability of oceanographic data is too sparse, at present, to adequately characterize these terms, as this requires high-resolution flow measurements in remote and topographically complex areas. This limit is largely ascribed to the lack of ocean observing systems suitably designed for the survey of extended regions of the ocean NEXUSS​ ​CDT bottom boundary layer. Existing AUVs are not capable of performing long-range operation at very close proximity to the ocean’s bottom, thus highlighting the need for a purposely-designed system especially suited for persistent navigation immediately adjacent to the sea bottom. The aim of this project is to extend the existing research in soft-bodied cephalopod-inspired underwater vehicles with the aim to develop a prototype (TRL 2 to 3) long-range autonomous vehicle purposely designed for measurement of oceanographic data at very close proximity with the sea bottom.

Soft-robots are regarded as a viable tool for enhanced safety and simplified control. In the aquatic environment, the inherent flexibility of soft-bodied vehicles is exploited to address the problem of robot-environment interaction (Giorgio-Serchi et al., 2016 ). Soft machines are less prone to cause damage or suffer damage from impacts, thus providing an inherently safe tool for navigation at close quarter with the sea bottom. In addition, the work performed by Weymouth et al. (2015) demonstrates that enhanced propulsion efficiency can be obtained in pulsed-jetting vehicles by exploiting the augmented thrust due to the external shape-variation of the vehicle. Starting from the existing work on bioinspired aquatic soft-robots, the candidate will investigate the issues surrounding the design and control of a vehicle capable of performing mapping of internal wave momentum fluxes in the vicinity of an abyssal hill whose typical size are 50 to 300m in height and 2 to 8 km in width. The candidate will start by devising a hypothetical bottom boundary-layer surveying mission and based on mission specifications (duration, mapping area and vehicle payload), will then be able to perform prototype characterization and optimization. In the second stage of the program, the candidate will be required to undertake the development of the control of the vehicle, eventually testing this in one of the facilities available to the NEXUSS partnership. These tasks offer the opportunity for a PhD student to combine a variety of interdisciplinary skills which range from oceanography to engineering.

This project provides state-of-the-art, highly interdisciplinary training in the application and development of cutting-edge Smart and Autonomous Observing Systems for the environmental sciences. The candidate will be supervised by a team with varied background (oceanography, hydrodynamics and robotics) which will foster the adoption of an interdisciplinary approach to project development. The candidate will be given extensive opportunities to expand his/her multi-disciplinary outlook through interactions with a wide network of academic, research and industrial / government / policy partners. The student will be registered at The Fluid Structure Interaction Research Group of the University of Southampton and hosted at National Oceanographic Institution Southampton and the Heriot-Watt University. The candidate will be encouraged to attend MSc classes from many of the course offered at the University of Southampton or any of the partner institutions which he/she considers beneficial to the accomplishment of NEXUSS​ ​CDT his/her doctoral training. These may include: Robotics System (ELEC3201), Maritime Robotics (SESS6072), Advanced Control Design (SESG6036), etc.