@article {6121, title = {Position, Orientation and Velocity Detection of Unmanned Underwater Vehicles (UUVs) Using an Optical Detector Array}, volume = {17(8)}, year = {2017}, month = {July 27}, pages = {1741}, publisher = {MDPI Publishing}, abstract = {

This paper presents a proof-of-concept optical detector array sensor system to be used in Unmanned Underwater Vehicle (UUV) navigation. The performance of the developed optical detector array was evaluated for its capability to estimate the position, orientation and forward velocity of UUVs with respect to a light source fixed in underwater. The evaluations were conducted through Monte Carlo simulations and empirical tests under a variety of motion configurations. Monte Carlo simulations also evaluated the system total propagated uncertainty (TPU) by taking into account variations in the water column turbidity, temperature and hardware noise that may degrade the system performance. Empirical tests were conducted to estimate UUV position and velocity during its navigation to a light beacon. Monte Carlo simulation and empirical results support the use of the detector array system for optics based position feedback for UUV positioning applications.

}, doi = {10.3390/s17081741}, url = {http://www.mdpi.com/1424-8220/17/8/1741}, author = {Eren, Firat and S. Pe{\textquoteright}eri and May-Win Thein and Yuri Rzhanov and Celikkol, Barbaros and Swift, Robinson} } @article {5253, title = {Detector Array Design for Optical Communication Between Unmanned Underwater Vehicles (UUVs)}, volume = {40(1)}, year = {2016}, pages = {18-26}, publisher = {IEEE Oceanic Engineering Society}, keywords = {detector array, optical communication, uuv}, author = {Eren, Firat and S. Pe{\textquoteright}eri and Yuri Rzhanov and May-Win Thein and Celikkol, Barbaros} } @article {5751, title = {Underwater-Detector Array for Optical Communication and Laser Beam Diagnostics}, year = {2016}, month = {Apr 17 - 21}, address = {Baltimore, MD}, keywords = {laser beam diagnostics, Lasers, optical communication, underwater detector array}, author = {S. Pe{\textquoteright}eri and Eren, Firat and May-Win Thein and Yuri Rzhanov and Matthew Birkebak} } @proceedings {5697, title = {Depth Adaptive Hydrographic Survey Behavior for Autonomous Surface Vessels}, year = {2015}, month = {Oct 19 - 22}, publisher = {IEEE}, address = {National Harbor, MD}, abstract = {
A large portion of autonomous ocean mapping surveys are currently performed by autonomous underwater vehicles, which have the ability to maintain a constant vertical distance above the seafloor by controlling their altitude. This allows for a multibeam sonar system with a fixed angular swath to maintain the same width of coverage along a trackline. Therefore, even in environments where the depth is previously unknown, survey missions can be planned before deployment using fixed line intervals. Many autonomous surface vessels (ASVs) have inherited this operational paradigm and execute linear survey tracklines with preplanned waypoints. However, since ASVs are limited to operation on the surface, the swath width varies with depth and preplanned paths will leave gaps in coverage or reduce efficiency by acquiring unnecessary overlap between subsequent lines.
To achieve the most efficient and complete surveys without human guidance, a set of algorithms and behaviors have been developed to guide sonar survey acquisition in real-time. The inputs to the path planning system are a polygonal region to be surveyed and starting line. In typical operation, the starting line would be chosen as the offshore (deeper) side of the polygon and would be oriented parallel to bathymetric contours. The autonomous control system navigates the vessel along the starting line, acquiring depth data from the sonar system. At the end of the path, the recorded swaths from the sonar are processed to determine an accurate edge of coverage, eliminating poor quality pings if necessary. A subsequent path is then planned to achieve desired coverage.
The path is based on the minimum swath widths over a specified interval to ensure full overlap at all locations. The minimum width points are used to create a new line along the edge of the coverage, from which perpendicular offsets of the swath width are used to determine the waypoints of the next survey track line. An overlap percentage may be specified to compensate for increased uncertainty in outer beam measurements. After generating the initial new trackline, this line is analyzed for conditions that would be detrimental to survey acquisition, such as sharp turns, looping segments and departure from the desired survey region. Removing waypoints in this step will sometimes leave gaps in subsequent survey coverage, but increases data quality through more predictable and smooth ASV motion. As a final step, tracklines are extended to the edges of the desired coverage region for full coverage. This operation is similar to that presented by Bourgeois [3], but uses a different methodology to guarantee overlap for subsequent lines.
The new trackline is sent to the autonomous control system which will plan a turn to the beginning of the next line, taking into account the minimum radius of the ASV and executing a modified Williamson turn if necessary. A lead to the first point is taken into account to allow the vessel to have a steady heading when entering the survey region. The process of acquiring coverage and planning tracklines is repeated until the survey region has been fully covered, at which time the data is analyzed for gaps resulting from the smoothing step or poor data. These can then be addressed following an optimal path to ensure complete coverage of the region.
At any time during the survey, if the sonar data indicates reliable shallower depths than a specified threshold, or exceeds a gradient approaching that depth, the ASV will break the planned survey path and return to known safe water from previously acquired data. It will then proceed near the detected underwater obstacle along the edge of the previous swath to determine if a safe passage is possible. Subsequent trackline planning then takes into account this obstacle and attempts to determine if safe passage is possible inshore (for an isolated rock or sandbar), or if the survey should be concluded for that region (for example when the shoreline is reached). A simulator that uses a previously acquired gridded depth data has been developed to test the path planning algorithms.
The path planning algorithm and survey behaviors have also been implemented for the MOOS-IvP marine autonomy system for application to survey ASVs. While no swath sonar capable ASV is currently available for testing at the University of New Hampshire, the basic operation of the system is being tested with single beam sonar data on a 5 ft NOAA EMILY ASV.
}, keywords = {asv, autonomous vehicle, autonomy, hydrography, path planning}, author = {Damian Manda and May-Win Thein and Andrew A. Armstrong} } @article {5696, title = {A Flexible, Low-Cost MOOS-IvP Based Platform for Marine Autonomy Research}, year = {2015}, month = {Jul 22-23}, address = {MIT}, abstract = {
As part of an effort to research collaborative autonomy behaviors between multiple unmanned surface and underwater vehicles, a hardware and software system has been developed for control of autonomous surface vessels (ASVs). This system is designed to be flexible in application to diverse platforms and ability to execute complex missions. In order to facilitate duplication across many deployments, the cost of the full system is minimized by leveraging mass produced, open source hardware and software.
MOOS-IvP is used as the central data assimilation and decision making software. Stock supplied and newly developed IvP behaviors are used to plan the trajectory for the ASV and can be customized to suit platform requirements. A graphical interface is available for setting missing configuration parameters to simplify deployment by those not fully versed in MOOS mission file creation. Sensor data is assimilated through either MOOS interface drivers or using ROS software and then passed to MOOS for use by the IvP helm and navigation controller. Incorporating ROS allows flexibility in sensor selection as many drivers already exist in the community and can be quickly adapted to this autonomy system.
The hardware for the system is designed to be housed in a single watertight box. Onboard processing has been deployed on the low cost BeagleBone Black and Raspberry Pi 2 platforms. Low level sensor input and control output as well as fail-safes and human remote control are handled by an independent Arduino microcontroller. Position and orientation input can be accepted from an existing source on the vessel or use a MEMS INS for simple deployments. The autonomy system has been implemented on multiple small vessels including those with both gas and electric engines.
}, keywords = {asv, autonomous vehicle, autonomy, electronics, MOOS-IvP}, url = {http://oceanai.mit.edu/moos-dawg15/pmwiki/pmwiki.php?n=Talk.01-Manda}, author = {Damian Manda and Andrew D{\textquoteright}Amore and May-Win Thein and Andrew A. Armstrong} } @proceedings {5695, title = {A Low Cost System for Autonomous Surface Vehicle based Hydrographic Survey}, year = {2015}, month = {March 16 - 19}, abstract = {
Use of autonomous vehicles for hydrographic surveying has been primarily limited to underwater systems with autonomous surface vehicles only recently entering routine use. Operation on the ocean surface simplifies position measurement, relaxes power limitations and reduces hull sealing, which reduces design costs for vehicles. However, the existing systems for autonomous command and control are often proprietary, expensive and designed for a single platform.
The system developed at the Joint Hydrographic Center minimizes cost while maximizing functionality and flexibility by leveraging mass produced, open source hardware and software. Long range WiFi is utilized for monitoring the autonomous operation vessel and provides the ability to natively interface onboard sonar systems with acquisition software. A hobby radio control system is used for remote human override. Onboard processing uses an embedded Linux platform running the open source MOOS-IvP autonomy framework. Sensor input and control output as well as fail-safes are handled by an independent microcontroller. Position and orientation input can be accepted from an existing source on the vessel or use a MEMS INS for simple deployments. The total autonomy system cost is under $1000.
The system is being initially integrated and tested on the NOAA 65\” micro ASV EMILY for shallow water hydrography.
}, keywords = {asv, autonomous, hydrography}, author = {Damian Manda and May-Win Thein and Andrew D{\textquoteright}Amore and Andrew A. Armstrong} } @article {5254, title = {Evaluation of Detector Array Designs for Optical Communication Between Unmanned Underwater Vehicle}, year = {2014}, author = {Eren, Firat and S. Pe{\textquoteright}eri and May-Win Thein and Yuri Rzhanov and Celikkol, Barbaros and Swift, Robinson} } @article {5257, title = {An image processing approach for determining of relative pose of unmanned underwater vehicles}, year = {2014}, month = {April 7-10}, address = {Taipei, Taiwan}, author = {Yuri Rzhanov and Eren, Firat and S. Pe{\textquoteright}eri and May-Win Thein} } @article {5256, title = {Pose Detection and control of multiple unmanned underwater vehicles using optical feedback}, year = {2014}, month = {April 7-10, 2014}, address = {Taipei, Tawian}, keywords = {detector array, optical communication, uuv}, author = {Eren, Firat and S. Pe{\textquoteright}eri and Yuri Rzhanov and May-Win Thein and Celikkol, Barbaros} } @proceedings {5137, title = {Characterization of optical communication in a leader-follower unmanned underwater vehicle formation}, volume = {8724}, year = {2013}, month = {April 29 - May 3}, publisher = {SPIE}, address = {Baltimore, MD, USA}, abstract = {

As part of theresearchto development an optical communication design of a leader-follower formation between unmanned underwater vehicles (UUVs), this paper presents light field characterization and design configuration of the hardware required to allow the use of distance detection between UUVs. The studyspecifically is targeting communication between remotely operated vehicles (ROVs). As an initial step in this study, the light field produced from a light source mounted on the leader UUV was empirically characterized and modeled. Based on the light field measurements, a photo-detector array for the follower UUV was designed. Evaluation of the communication algorithms to monitor the UUV\’s motion was conducted through underwater experiments in the Ocean Engineering Laboratory at the University of New Hampshire. The optimal spectral range was determined based on the calculation of the diffuse attenuation coefficients by using two different light sources and a spectrometer. The range between the leader and the follower vehicles for a specific water type was determined. In addition, the array design and the communication algorithms were modified according to the results from the light field.

}, keywords = {light attenuation, optical communication, simulation, Unmanned underwater vehicle, water clarity}, author = {Eren, Firat and S. Pe{\textquoteright}eri and May-Win Thein} } @proceedings {5102, title = {Distance Detection of Unmanned Underwater Vehicles by Utilizing Optical Sensor Feedback in Leader-Follower Formation}, year = {2012}, month = {Oct 14 - Oct 19}, publisher = {IEEE/MTS}, address = {Hampton Falls, VA}, author = {Eren, Firat and May-Win Thein and Celikkol, Barbaros and S. Pe{\textquoteright}eri and Decew, Jud} }