Design and analysis of an improved Wave Glider recovery system

Abstract

The Sensor Hosting Autonomous and Remote Craft (SHARC) Wave Glider system is an autonomous surface vehicle widely used for long-duration at-sea data collection and acoustic monitoring. The system is manufactured by Liquid Robotics Inc. (LRI) and consists of two components (1) a surface float housing sensors, batteries, solar panels, and communication systems, and (2) a submerged propulsor (glider) containing six hinged hydrofoils. A third component, a submerged body housing additional sensors, may be towed behind the propulsor. While system launch is relatively straight forward, recovery of the system is challenging and incurs high risk. Challenges include (1) the Wave Glider system contains multiple components, (2) forward motion of the system cannot easily be arrested, and (3) the ship conducting recovery operations often has a high freeboard. Need for an improved recovery system is desired, particularly for the United States Naval Oceanographic Office (NAVOCEANO), as current recovery methods require personnel in small boats or swimmers in the water to control the vehicle and attach lifting lines. These procedures are hazardous to both personnel and equipment and are limited to low sea states. This project, conducted by a team of five undergraduate students and two advisers, designed and evaluated multiple alternatives as viable recovery solutions. Based on design and operational requirements, the final proposed solution is two-part. The first is a remotely actuated inflatable lift bag attached to the stern of the submerged propulsor that will halt forward movement when inflated; and the second is a vertical cable loop mounted on the surface float to facilitate lifting of the float, propulsor and towed payloads. The proposed solution was demonstrated to be feasible and met all design requirements, with an emphasis on simplicity.

A low-cost wave/solar powered unmanned surface vehicle

“…A hull length of 1.2 meters was determined to be the desired size as it is large enough to place the solar panels and the electronic components. This dimension is less than half the length of "Wave Glider SV3" which is 3.05 meters in length [8]. Together, the two hulls can support up to 75kg.…”

Effects of Connection Type between Surface Vessel and Submersible Propeller on Motion Performance of Wave Glider

“…On design and optimization of Wave Glider, Li et al [4,5] conducted a preliminary study of whole performance of the Wave Glider, provided the design basis for the length and width of the glider and the length of the connecting cable, and realize the modeling and analyzing of Wave Glider by using the co-simulation of ADAMS and MATLAB software; Wang et al [6] proposed an optimization method based on the Latin Hypercube Sampling (LHS) method and Computational Fluid Dynamics (CFD) method for the submersible propeller which is Blended Wing Body (BWB) layout, and obtained an optimization model for the BWB Water Glider; Tian et al [7] introduced the flexible webbed wings based on the researches of traditional Wave Glider, conducted an intensive study on the propulsion principle of the Wave Glider with webbed wings (WGWW), established a driving force calculation model of the flexible webbed wing and realized the glide function of the WGWW; J. Rice et al [8] designed and analyzed a recovery system to improve Wave Glider, the proposed solution was demonstrated to be feasible and met all design requirements, with an emphasis on simplicity.…”