Brian Bingham

Techniques for Deep Sea Near Bottom Survey Using an Autonomous Underwater Vehicle

This paper reports the development and at-sea deployment of a set of algorithms that have enabled the autonomous underwater vehicle ABE to conduct near-bottom surveys in the deep sea. Algorithms for long baseline acoustic positioning, terrain-following, and automated nested surveys are reported.

Robotic Tools for Deep Water Archaeology : Surveying an Ancient Shipwreck with an Autonomous Underwater Vehicle

The goals of this article are twofold. First, we detail the operations and discuss the results of the 2005 Chios ancient shipwreck survey. This survey was conducted by an international team of engineers, archaeologists, and natural scientists off the Greek island of Chios in the northeastern Aegean Sea using an autonomous underwater vehicle (AUV) built specifically for high‐resolution site inspection and characterization. Second, using the survey operations as context, we identify the specific challenges of adapting AUV technology for deep water archaeology and describe how our team addressed these challenges during the Chios expedition. After identifying the state of the art in robotic tools for deep water archaeology, we discuss opportunities in which new developments and research (e.g., AUV platforms, underwater imaging, remote sensing, and navigation techniques) will improve the rapid assessment of deep water archaeological sites. It is our hope that by reporting on the Chios field expedition we can both describe the opportunities that AUVs bring to fine‐resolution seafloor site surveys and elucidate future opportunities for collaborations between roboticists and ocean scientists. (Less)

Underwater Acoustic Navigation with the WHOI Micro-Modem

The WHOI Micro-Modem is a compact, low-power acoustic transceiver that can provide both acoustic telemetry and navigation. Its size and versatility make it ideal for integration in autonomous underwater vehicles (AUVs). The modem supports the use of both broadband and narrowband transponders for long baseline navigation systems, has a modem-to-modem ranging capability, and can be configured to provide synchronous oneway ranging, when integrated with a precision clock. This paper gives an overview of the different navigation systems supported by the Micromodem and presents the results from field tests conducted on the SeaBED AUV in deployments in Greece, the Bluefin AUV, and whale localizations in the Stellwagen Bank Marine Sanctuary

Method for rapid localization of seafloor petroleum contamination using concurrent mass spectrometry and acoustic positioning

Locating areas of seafloor contamination caused by heavy oil spills is challenging, in large part because of observational limitations in aquatic subsurface environments. Accepted methods for surveying and locating sunken oil are generally slow, labor intensive and spatially imprecise. This paper describes a method to locate seafloor contamination caused by heavy oil fractions using in situ mass spectrometry and concurrent acoustic navigation. We present results of laboratory sensitivity tests and proof-of-concept evaluations conducted at the US Coast Guard OHMSETT national oil spill response test facility. Preliminary results from a robotic seafloor contamination survey conducted in deep water using the mass spectrometer and a geo-referenced acoustic navigation system are also described. Results indicate that this technological approach can accurately localize seafloor oil contamination in real-time at spatial resolutions better than a decimeter.

Multi-robot cooperative control for monitoring and tracking dynamic plumes

We study robotic tracking of dynamic plume front modeled by the advection-diffusion equation in this paper. Different from existing work purely relying on gradient measurement, the transport model of pollution source is explicitly considered in tracking control design. We first study the problem using a single robot and solve the problem in an estimation and control framework. We then extend it to the multi-robot case in a nearest-neighbor communication structure, and have the robots take formation along the plume front. The distributed control is scalable to a large number of robots. Simulation results show satisfactory performances of the proposed method.

Integrating Precision Relative Positioning into JASON/MEDEA ROV Operations

Advances in navigation continue to add precision and robustness to undersea operations. Two challenges limit navigation of the JASON/MEDEA two-vehicle ROV system: acoustic noise from JASON’s hydraulic systems and lack of a direct relative position measurement between the two vehicles. This paper describes successful integration of the SHARPS ranging system—enabling precise relative positioning that is robust with respect to acoustic noise. We discuss four aspects of the installation: the capabilities of SHARPS as installed on the ROVs, the estimation theory predicted performance of the system design, the proof-of-concept navigation results from field deployments, and the operational utility of the SHARPS capability. The SHARPS installation integrates an important capability into the ROV system, enhancing the data product for science while adding safety and flexibility to the at-sea operations. hangs below the dynamically positioned (DP) surface ship via an armored cable carrying fiber-optic communications and electric power. The vehicle’s large, concentrated mass decouples the ROV, JASON, from the surface ship’s motion, keeping the armored cable vertical and reducing the chance of snap-loading from surface heave. A 35 m neutrally buoyant tether connects the two vehicles, extending the communication and electric power to JASON. Operators move the ship to position MEDEA vertically over-top of JASON, maintaining visual contact using a down-looking low-light camera on MEDEA and adjusting the vertical separation between the two vehicles. During lowerings lasting as long as 72 hours, JASON samples and surveys the seafloor at depths of up to 6,500 m. One of the most important data products of this work is the record of navigation estimates. These records allow scientists to systematically and quantitatively explore the seafloor. Because of the JASON/MEDEA two-body configuration, short baseline (SBL) relative positioning improves the navigation solution, allowing safer, more flexible operation. Operators navigate the JASON/MEDEA ROV system using a combination of long baseline (LBL) positioning and Doppler velocity log (DVL) dead-reckoning. Both JASON and MEDEA have LBL receivers, but only JASON has a DVL to measure velocity relative to the seafloor. There are two challenges with the current navigation solution. First, LBL reception at JASON’s receiver is inconsistent or non-existent due to acoustic noise and limited line-of-sight. JASON’s hydraulic motors power much of the on-board utilities: the two manipulators, tool basket, suction pumps, etc. The associated acoustic

Integrating in-situ chemical sampling with AUV control systems

The utility of autonomous underwater vehicles continues to expand as powerful new in-situ sensor technologies are developed for AUV operation. However, these analytical sensors are typically configured to collect and log data as independent payloads without the benefit of feedback from other payload sensors or vehicle navigation systems. This paper explores conceptual frameworks for integrating payload sensors in various degrees of real-time data assimilation and adaptive operation. Several of the challenges to coupling chemical sensor payloads in closed-loop architecture with acoustic, visual and navigation control systems are examined. Specific examples are provided as to how information sharing and coupled decision making processes may improve payload data interpretation and validation as well as increase the overall efficiency of AUV mission strategies. Data is presented from deployments of the Seabed submersible, a passively stable, hover-capable AUV designed for operation to 2000 meters. During these deployments the Seabed vehicle was arrayed with a payload of optical, acoustic, and chemical sensors to identify and map structures associated with ocean bottom methane sources on the Atlantic slope of North America. Results from these deployments are discussed and a collection of general principles is suggested for integration of biological and chemical sensors as payload with active feedback aboard AUVs. The authors conclude with suggestions for possible scientific applications that can be addressed using levels of technology presently available as well as how incremental advancements in AUV payload integration will present profound new opportunities to explore and understand our world.

Hypothesis grids: improving long baseline navigation for autonomous underwater vehicles

Navigation continues to fundamentally limit our ability to understand the underwater world. Long baseline navigation uses range measurements to localize a remote vehicle using acoustic time-of-flight estimates. For autonomous surveys requiring high precision navigation, current solutions do not satisfy the performance or robustness requirements. Hypothesis grids represent the survey environment capturing the spatial dependence of acoustic range measurement, providing a framework for improving navigation precision and increasing the robustness with respect to non-Gaussian range observations. Prior association probabilities quantify the measurement quality as a belief that subsequent observations will correspond to the direct-path, a multipath, or an outlier as a function of the estimated location. Such a characterization is directly applicable to Bayesian navigation techniques. The algorithm for creating the representation has three main components: Mixed-density sensor model using Gaussian and uniform probability distributions, measurement classification and multipath model identification using expectation-maximization (EM), and grid-based spatial representation. We illustrate the creation of a set of hypothesis grids, the feasibility of the approach, and the utility of the representation using survey data from the autonomous benthic explorer (ABE)

Passive and active acoustics using an autonomous wave glider

The recently developed wave glider has the potential to be an effective unmanned platform for acoustic applications. We present the results of a variety of experiments that quantify this potential. The radiated self-noise of the autonomous platform is evaluated using an integrated passive acoustic recorder during a set of field trials off the coast of Hawaii. We present the radiated noise spectra from these trials to illustrate the dependence on hydrophone location and sea state. Using the same instrumentation, we demonstrate the ability of a modified wave glider to detect marine mammals using passive acoustic monitoring techniques. We also evaluate the performance of the wave glider operating as an active acoustic gateway, highlighting the potential of this platform to serve as a navigation reference and communications relay for scientific, industrial, and military subsea assets. To demonstrate the potential of the wave glider platform to support acoustic navigation, we assess the performance of time-of-flight range estimation and seafloor transponder localization. These tests were performed using commercial off-the-shelf acoustic positioning hardware integrated with the wave glider to illustrate that the low self-noise of the wave glider makes it possible to achieve acoustic positioning performance similar to previously reported results. Finally, we show that the glider can operate as a station-keeping surface communications gateway and provide recommendations for its use.

Predicting the navigation performance of underwater vehicles

In this paper we present a general framework for predicting the positioning uncertainty of underwater vehicles. We apply this framework to common examples from marine robotics: standalone long baseline (LBL) positioning and integrated LBL reference and Doppler velocity log (DVL) dead-reckoning.