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Multi-domain autonomous sensor networks are essential for reducing capability gaps between different kinds of sensing platforms. Design of an efficient network can provide seamless sensing capability. Furthermore, to achieve operational persistency, nodes of the networks are required to be robust and affordable. Field robotics has other challenges in addition to robustness and in particular the logistics...
When a mariner navigates into an unfamiliar area, he/she uses a nautical chart to familiarize him/herself with the environment, determine the locations of hazards, and decide upon a safe course of travel. An autonomous surface vehicle (ASV) would gain a great advantage if, like its human counterpart, it can learn to read and use the information from a nautical chart. Electronic Nautical Charts (ENCs)...
Several approaches can be identified in the literature for area decomposition: Grid based methods, Cellular decomposition and Boustrophedon (or Morse) decomposition. This paper proposes a novel discretization method for the area based on computational geometry approaches. By using a Constrained Delaunay Triangulation, a complex area is segmented in cells which have the size of the projected field...
Phytoplankton patches in the coastal ocean have important impacts on the patterns of primary productivity, the survival and growth of zooplankton and fish larvae, and the development of harmful algal blooms (HABs). We desire to observe microscopic life in a phytoplankton patch in its natural frame of reference (which is moving with the ocean current), thereby permitting resolution of time-dependent...
In this paper, we present a first attempt toward experimental validation of a multi-robot strategy for tracking manifolds and Lagrangian coherent structures (LCS) in flows. LCS exist in natural fluid flows at various scales, and they are time-varying extensions of stable and unstable manifolds of time invariant dynamical systems. In this work, we present the first steps toward experimentally validating...
The MORPH project (FP 7, 2012–2016) aims at the development of efficient methods and tools to map the underwater environment in situations that defy existing technology. Namely, missions that involve underwater surveying and marine habitat mapping of rugged terrain and structures with full 3D complexity, including near-vertical cliffs. Potential applications include the study of cold water coral reefs...
This paper considers mission design strategies for mobile robots whose task is to perform spatial sampling of a static environmental field, in the framework of compressive sensing. According to this theory, we can reconstruct compressible fields using O(log n) nonadaptive measurements (where n is the number of sites of the spatial domain), in a basis that is “incoherent” to the representation basis...
Observation of spatially distributed oceanographic phenomena using sensor-enabled AUVs involves a trade-off between coverage and resolution. In this paper the performance of adaptive variation sensitive sample distributions in such a sensing task is evaluated under mission constraints such as finite measurement time and finite vehicle speed and compared to uniform sampling. The relative performance...
The paper studies the observability properties of the relative localization of two Autonomous Underwater Vehicles (AUVs) equipped with depth sensors, linear/angular velocity sensors, and communication devices with range measurement. The conditions that ensure observability of the linearized model and locally weak observability of the nonlinear system are derived. An Extended Kalman Filter is then...
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