Amy Kukulya

Autonomous Docking Demonstrations with Enhanced REMUS Technology

As autonomous underwater vehicles (AUVs) become more pervasive and enter common usage, systems that expand their capabilities, extend their range, and/or permit operation in denied areas become essential. A dock is one method of achieving these goals. An autonomous dock for an AUV provides the capability to greatly increase the duration and extent of AUV operations, provided the dock has a substantially greater energy supply than the AUV. Other docking station applications include the possibility of installation onto a cabled Oceanographic observatory, thus providing unlimited power for battery recharge and continuous data communications. This paper presents the design, development, testing, and results of recent field demonstrations of a compact bottom-mounted docking station for a modified REMUS-100 series AUV. In addition to the dock development, the REMUS vehicle was enhanced with a new, modular endcap to facilitate the installation of modular sensors to the vehicle for the docking program. These sensors include a new digital ultra-short baseline (USBL) acoustic homing array and a periscope camera for sea-surface observations. The USBL homing array along with DVL velocity and altitude information provided the capability of the AUV to reliably navigate along a preprogrammed glidepath into an entrance nozzle of the dock. A unique challenge of this second generation docking system was the requirement for small size and near-bottom entrance into the dock

Development of the REMUS 600 autonomous underwater vehicle

The Oceanographic Systems Laboratory of the Woods Hole Oceanographic Institution has developed the REMUS 600, a new 12.75 inch (32.385 cm) diameter autonomous underwater vehicle that will be used to carry mine countermeasures sensors for the Office of Naval Research. Vehicle Control Technologies has been tasked by ONR to develop autopilot and simulation software for several REMUS 600 sensor configurations, with the objective of achieving enhanced platform steadiness to improve sensor performance in the shallow water and very shallow water environment. The most stringent motion steadiness requirements for the REMUS 600 vehicle are derived from the image forming specifications of a new side-looking synthetic aperture sonar developed for ONR by the Penn State Applied Physics Laboratory and the Coastal Systems Station, Panama City, Florida. This payload necessitated the use of a forward fin section for enhanced control authority. This forward fin section gives the vehicle the ability to command vertical and horizontal sideslips, in addition to roll, pitch, and yaw control, using independently commanded fins. This is a unique capability for a vehicle of this class. In addition, the 12.75 inch diameter vehicle class offers new capabilities for endurance and payload capacity. The REMUS 600 software architecture has been designed with the flexibility to accommodate various payloads and both the VCT autopilot and the Woods Hole autopilot. We present the VCT approach to autopilot design which makes use of a high-fidelity hydrodynamics model, software in the loop simulation test, vehicle motion steadiness performance predictions, and post-test validation. The REMUS 600 vehicle has collected extensive in-water data. We present performance results based on this data

Under-ice operations with a REMUS-100 AUV in the Arctic

Use of a REMUS-100 AUV to obtain hydrographic observations beneath coastal sea ice offshore of Barrow, Alaska is described. The work is motivated by the desire to obtain cross-shore hydrographic transects that would provide estimates of the transport of relatively dense, salty water from the Chukchi Sea to the Arctic Ocean in winter. The horizontal scales (∼10 km), maximum water depths (∼100 m) and desired measurements (temperature, salinity and velocity vs. depth) in the study region match the capabilities of a small AUV such as the REMUS-100. It was recognized that achieving the science goals would require increasing the range of acoustic navigation and communication as well as developing a robust approach to through-ice deployment and recovery. These needs drove three modifications to the AUV: 1) Incorporation of a lower frequency (10 kHz) transducer and associated hardware for navigation and communication, 2) Addition of special-purpose sensors and hardware in a hull extension module, 3) Development of a homing algorithm utilizing an Ultra-Short Base Line (USBL) array in the AUV nose cap. In March 2010, eight days of field work offshore of Barrow provided successful demonstration of the system. A total of 14 km of track lines beneath a coastal ice floe were obtained from four missions, each successfully terminated by net-capture recovery.

Subsurface observations of white shark Carcharodon carcharias predatory behaviour using an autonomous underwater vehicle

In this study, an autonomous underwater vehicle (AUV) was used to test this technology as a viable tool for directly observing the behaviour of marine animals and to investigate the behaviour, habitat use and feeding ecology of white sharks Carcharodon carcharias near Guadalupe Island off the coast of Mexico. During the period 31 October to 7 November 2013, six AUV missions were conducted to track one male and three female C. carcharias, ranging in estimated total length (LT ) from 3·9 to 5·7 m, off the north-east coast of Guadalupe Island. In doing so, the AUV generated over 13 h of behavioural data for C. carcharias at depths down to 90 m. The sharks remained in the area for the duration of each mission and moved through broad depth and temperature ranges from the surface to 163·8 m depth (mean ± S.D. = 112·5 ± 40·3 m) and 7·9-27·1° C (mean ± S.D. = 12·7 ± 2·9° C), respectively. Video footage and AUV sensor data revealed that two of the C. carcharias being tracked and eight other C. carcharias in the area approached (n = 17), bumped (n = 4) and bit (n = 9) the AUV during these tracks. This study demonstrated that an AUV can be used to effectively track and observe the behaviour of a large pelagic animal, C. carcharias. In doing so, the first observations of subsurface predatory behaviour were generated for this species. At its current state of development, this technology clearly offers a new and innovative tool for tracking the fine-scale behaviour of marine animals.

Characteristics of an autonomous underwater vehicle with a towed hydrophone array

This paper presents the performance results of a REMUS AUV, a proven low noise vehicle with precise navigation, that was modified by the addition of a prototype towed hydrophone array. A quiet, acoustically sensitive synthetic aperture sonar at low frequencies required a 10 m long acoustic section of the array separated from the vehicle with a 10 m long tow cable. A drogue was used to produce an initial drag and to minimize motions at the end of the array. REMUS was designed to carry a wide variety of sensors but, the 10 meter towed array presented many challenges. Unlike vehicles with thrust vectoring, REMUS requires forward motion using three axis control to maintain constant depth without the added drag of fin control. In light of this, several hardware and software adjustments were required to ensure successful long-range missions with the system. The vehicle adjustments, along with the results from at-sea engineering trials of the vehicle-array system are presented and demonstrate the ability of the system to maintain a constant depth with a stable array tow. Effects of the added drag on the vehicle were evident in the on board recorded data, which enabled the adjustment of vehicle control through software and mechanical considerations such as attachment point of the array to the vehicle. Rapid improvement in vehicle performance in between missions was achieved on board the support ship as a direct result of the ability to view and interpret mission data in the field. Based on the engineering trials with this vehicle array system, estimates of the vehicle and array system performance including power requirements, diving capability, turning capability, effects of currents, and navigational errors are discussed

An autonomous underwater vehicle towed hydrophone array for ocean acoustic measurements

An autonomous underwater vehicle (AUV) with a towed hydrophone array (THA) can provide the capability of mobile‐single‐ship operation for both short‐range single path and long range synthetic aperture experiments. A low noise towed array for an AUV (REMUS) has been developed to demonstrate the feasibility and utility of such measurements. Previous measurements of AUV radiated noise indicated levels that would limit measurements by hull arrays providing a rational for a THA. A small‐diameter fluid‐filled prototype hydrophone array was developed and tested to ensure adequate sensitivity and system noise levels. The digital recording system (DRS) consisted of mini‐disc recorders with a band width of 20 kHz housed in a tube attached to the AUV. This combined system (REMUS, DRS, and THA) was used to conduct a proof of concept test in Dodge Pond. This paper presents the results that show, in the Sea State 0 noise field of Dodge Pond, array system self noise was less than the ambient and vehicle noise was manage...

Multi-vehicle autonomous tracking and filming of white sharks Carcharodon carcharias

In recent years, great technological subsurface advancements have been made to observe and study Carcharodon carcharias, white sharks with autonomous underwater vehicles (AUVs) [1]. Prior to 2011, tracking pelagic predators like sharks was limited to using active tracking from boats [2] and passive acoustic arrays [3]. These aforementioned techniques proved to be limited by logistics such as weather and boat maneuverability as well as providing poor spatial resolution since fish movements were mimicked by the tracking vessel.

Monitoring of macroalgae (kelp) farms with autonomous underwater vehicle-based split-beam sonar

The long-term goal of ARPA-Es MARINER (Macroalgae Research Inspiring Novel Energy Resources) program is to increase the scale of offshore kelp aquaculture so that biofuel may be derived from macroalgae. An autonomous underwater vehicle (AUV) system including acoustic, optic, and environmental sensors has been developed for the purposes of monitoring these large-scale kelp farms. The primary sensor for observing farm infrastructure such as horizontal longlines (from which the kelp grows) as well as kelp growth is a broadband split-beam sonar system. Structural information, such as droop in the longlines, is available from time-of-flight of the acoustic echoes. Growth of kelp is quantified from both time-of-flight and volume backscattering echo data. Experimental results from ocean measurements taken with the REMUS 100 AUV on longlines are presented, along with preliminary processing techniques for estimating longline position and macroalgae extent for vehicle control and farm mapping purposes [work supported by ARPA-E.]The long-term goal of ARPA-Es MARINER (Macroalgae Research Inspiring Novel Energy Resources) program is to increase the scale of offshore kelp aquaculture so that biofuel may be derived from macroalgae. An autonomous underwater vehicle (AUV) system including acoustic, optic, and environmental sensors has been developed for the purposes of monitoring these large-scale kelp farms. The primary sensor for observing farm infrastructure such as horizontal longlines (from which the kelp grows) as well as kelp growth is a broadband split-beam sonar system. Structural information, such as droop in the longlines, is available from time-of-flight of the acoustic echoes. Growth of kelp is quantified from both time-of-flight and volume backscattering echo data. Experimental results from ocean measurements taken with the REMUS 100 AUV on longlines are presented, along with preliminary processing techniques for estimating longline position and macroalgae extent for vehicle control and farm mapping purposes [work suppor...

Acoustic sensing of macroalgae (kelp) for large-scale marine biomass production

An important component of the future use of large-scale offshore farms to grow macroalgae (kelp) will be remote monitoring of infrastructure, the environment, and plant health over areas so large that manual inspection is not practical. A new program, the Advanced Research Projects Agency-Energys Macroalgae Research Inspiring Novel Energy Resources (ARPA-E MARINER), has the long-term goal of domestic energy production using biofuel derived from macroalgae. As part of that program, an integrated sensing system is being developed for unmanned underwater vehicle (UUV) monitoring of infrastructure, macroalgae growth, water properties, and associated organisms in experimental offshore macroalgae farms occupying areas square kilometers in size. A critical component of this monitoring system is acoustic sensing using a split-beam sonar system. Time-of-flight and volume backscattering data from the echosounder will be used to determine the thickness of growth and percentage volume inhabited of macroalgae. The objective is to provide a map correlated to biomass distribution variability across the farm area. Data will also be collected on aggregations of fish and zooplankton both within and outside the farm. Early results from local tests on sugar kelp will be presented, including initial research into the correlation between these acoustic data and biomass.An important component of the future use of large-scale offshore farms to grow macroalgae (kelp) will be remote monitoring of infrastructure, the environment, and plant health over areas so large that manual inspection is not practical. A new program, the Advanced Research Projects Agency-Energys Macroalgae Research Inspiring Novel Energy Resources (ARPA-E MARINER), has the long-term goal of domestic energy production using biofuel derived from macroalgae. As part of that program, an integrated sensing system is being developed for unmanned underwater vehicle (UUV) monitoring of infrastructure, macroalgae growth, water properties, and associated organisms in experimental offshore macroalgae farms occupying areas square kilometers in size. A critical component of this monitoring system is acoustic sensing using a split-beam sonar system. Time-of-flight and volume backscattering data from the echosounder will be used to determine the thickness of growth and percentage volume inhabited of macroalgae. The ob...

Development of a propeller driven long range autonomous underwater vehicle (LRAUV) for under-ice mapping of oil spills and environmental hazards: An Arctic Domain Center of Awareness project (ADAC)

The increasing level of commercial marine activity in high latitudes creates an ever growing risk of oil spills. Even in logistically accessible, ice-free oceans, characterizing the extent and nature of a spill can be challenging as highlighted by the Deepwater Horizon incident. We propose to develop an AUV-based approach inspired by an existing small, long-range system, called the Tethys Long-Range AUV (LRAUV), in order to support the Arctic Doman Awareness Center (ADAC) for spill preparedness.