Lagrangian coherent structure assisted path planning for transoceanic autonomous underwater vehicle missions

Abstract

Transoceanic Gliders are Autonomous Underwater Vehicles (AUVs) for which there is a developing and expanding range of applications in open-seas research, technology and underwater clean transport. Mature glider autonomy, operating depth (0–1000 meters) and low energy consumption without a CO2 footprint enable evolutionary access across ocean basins. Pursuant to the first successful transatlantic glider crossing in December 2009, the Challenger Mission has opened the door to long-term, long-distance routine transoceanic AUV missions. These vehicles, which glide through the water column between 0 and 1000 meters depth, are highly sensitive to the ocean current field. Consequently, it is essential to exploit the complex space-time structure of the ocean current field in order to plan a path that optimizes scientific payoff and navigation efficiency. This letter demonstrates the capability of dynamical system theory for achieving this goal by realizing the real-time navigation strategy for the transoceanic AUV named Silbo, which is a Slocum deep-glider (0–1000 m), that crossed the North Atlantic from April 2016 to March 2017. Path planning in real time based on this approach has facilitated an impressive speed up of the AUV to unprecedented velocities resulting in major battery savings on the mission, offering the potential for routine transoceanic long duration missions.

Improving Resource Management for Unattended Observation of the Marginal Ice Zone Using Autonomous Underwater Gliders

“…Although the EDBS is effectively a real-time 1D path planner that optimizes for bathymetric constraints and water column currents along the vertical z-axis, the lowlevel energy resource management processes described here can be combined with higher-level xy-plane path planners that incorporate water current forecast modeling, sensor scheduling, and risk assessment (e.g., Galea, 1999;Yu et al, 2013;Timmons et al, 2016). Prior path planning work based on satellite-observed surface water currents has demonstrated current-augmented vehicle speed over-ground in excess of 1 m s −1 during transoceanic crossings (Ramos et al, 2018), improving energy efficiency while minimizing travel time.…”

“…Despite being relatively slow and minimally navigated, gliders offers a promising compromise between range, cost, and observational capability. Their inherent capability for high-endurance and unattended operation without need for acoustic navigation beacons has enabled this class of vehicle to successfully complete multiple trans-Atlantic missions (Willis, 2009;Ramos et al, 2018) and routinely operate in polar waters (Miles et al, 2016;Lee et al, 2017;Zhou et al, 2019). With appropriate modification, these vehicles may be viable for long-range Arctic missions requiring round-trip transits from ports of convenience.…”

Towards basin-scale in-situ characterization of sea-ice using an Autonomous Underwater Glider

“…With notable exceptions [Kaminski et al, 2010, Furlong et al, 2012, Boeing, 2017, most AUVs do not possess the required range to conduct basin-scale Arctic sea-ice surveys. AUGs, however, routinely operate in polar waters [Lee et al, 2017, Zhou et al, 2019, Miles et al, 2016, have successfully completed multiple trans-Atlantic missions [Ramos et al, 2018, Willis, 2009 and with appropriate modification, may be viable for basin-scale Arctic operations. Scaling up to persistent basin-scale synoptic observation using underwater platforms will require miserly power budgets coupled with low unit costs.…”

“…Although the EDBS is effectively a 1D path planner that optimizes for bathymetric constraints and water column currents along the vertical -axis, the low-level energy resource management processes described here can be combined with higher-level -plane path planners that incorporate water current forecast modeling and risk assessment. Prior path planning work based on satellite observed surface water currents has demonstrated currentaugmented vehicle speed over-ground in excess of 1 m s −1 during transoceanic crossings [Ramos et al, 2018], improving energy efficiency while minimizing travel time.…”

Hierarchical Motion Planning of AUVs in Three Typical Marine Environments

“…It solved the problem that a single AUV is difficult to carry out full coverage task with long range. Ramos, Garcia-Garrido et al [6] planned a path to optimize scientific impact and navigation efficiency according to the complex space-time structure of ocean flow field and dynamic system. They pre-planned the Silbo glider's mission to cross the North Atlantic from April 2016 to March 2017.…”