La presente invention concerne un systeme d'eclairage lumineux a distance (10) comportant un ... more La presente invention concerne un systeme d'eclairage lumineux a distance (10) comportant un sequenceur de systeme d'eclairage (18), permettant d'assurer une repartition sequentielle des signaux lumineux pour plusieurs dispositifs de repartition d'eclairage. Une source lumineuse (12) fournit au sequenceur d'eclairage (18) des signaux focalises (44, 46). Le sequenceur d'eclairage (18) comprend un scanner optique (22) et une commande electronique permettant de diriger de maniere selective les signaux lumineux (44, 46) vers des fibres optiques individuelles (20), appartenant a un systeme de repartition a fibres optiques. Les fibres optiques (20) assure le couplage des signaux lumineux aux dispositifs de repartition d'eclairage, ce qui permet d'obtenir un eclairage sequentiel conforme a un modele desire.
This paper describes a small underwater robot designed for experiments with sensor-actuator netwo... more This paper describes a small underwater robot designed for experiments with sensor-actuator networks. The robot is based on the mote platform, which is used extensively in the sensor networking community as an experimental testbed. The components and construction of the robot are described. Preliminary tests of depth regulation and temperature measurement are reported and analyzed.
Autonomous Underwater Vehicles (AUVs) are revolutionizing oceanography. Most high-endurance and l... more Autonomous Underwater Vehicles (AUVs) are revolutionizing oceanography. Most high-endurance and long-range AUVs rely on satellite phones as their primary communications interface during missions for data/command telemetry due to its global coverage. Satellite phone (e.g., Iridium) expenses can make up a significant portion of an AUV's operating budget during long missions. Slocum gliders are a type of AUV that provide unprecedented longevity in scientific missions for data collection. Here we describe a minimally-intrusive modification to the existing hardware and an accompanying software system that provides an alternative robust disruption-tolerant communications framework enabling cost-effective glider operation in coastal regions. Our framework is specifically designed to address multiple-AUV operations in a region covered by multiple networked base-stations equipped with radio modems. We provide a system overview and preliminary evaluation results from three field deployments using a glider. We believe that this framework can be extended to reduce operational costs for other AUVs during coastal operations.
A wireless network of buoys, two autonomous robotic boats, and an autonomous tethered vertical pr... more A wireless network of buoys, two autonomous robotic boats, and an autonomous tethered vertical profiling system were used to characterize phytoplankton dynamics and spatiotemporal changes in chemical and physical forcing factors in a small montane lake (Lake Fulmor, Idyllwild, California). Three deployments each year were conducted in 2005 and 2006 to examine seasonal changes in the structure of the lake and phytoplankton assemblage, as well as fine-scale temporal and spatial variations. The buoys yielded fine-scale temporal patterns of in situ fluorescence and temperature, while the vertical profiling system yielded two-dimensional, cross-sectional profiles of several parameters. The autonomous vehicles provided information on fluorescence and corresponding temperature patterns across the surface of the lake. Average, lake-wide chlorophyll concentrations increased 10fold seasonally, and strong anoxia developed in the hypolimnion during the summer. The latter process dramatically affected vertical chemical gradients in the 5 m water column of the lake. Small-scale spatial (,1 m) and temporal (minutes) heterogeneity in fluorescence were surprisingly large. These variations were due predominantly to vertical mixing of the phytoplankton assemblage and to phytoplankton vertical migratory behavior. Large peaks in fluorescence at 0.5-m occurred at very short time intervals (minutes) during all deployments, and appeared to be due to upward mixing of deeper dwelling eukaryotic phytoplankton during early-midsummer , or downward mixing of surface-associated cyanobacteria during late summer.
This paper describes the design, development, and initial application of a sensor-actuated networ... more This paper describes the design, development, and initial application of a sensor-actuated network for sensing and sampling microbial communities in aquatic ecosystems. The network consists of ten stationary buoys and one mobile robotic boat for real-time, in situ measurements and analysis of chemical and physical factors governing the abundance and dynamics of microorganisms at biologically relevant spatiotemporal scales. The goal of the network is to obtain high-resolution information on the spatial and temporal distributions of plankton assemblages and concomitant environmental parameters in aquatic environments using the in situ presence afforded by the network and to make possible network-enabled robotic sampling of hydrographic features of interest. This work constitutes advances in (1) real-time observing in aquatic ecosystems and (2) sensor actuated sampling for biological analysis.
ABSTRACT More than 70% of our earth is covered by water, yet we have explored less than 5% of the... more ABSTRACT More than 70% of our earth is covered by water, yet we have explored less than 5% of the aquatic environment. Aquatic robots, such as autono- mous underwater vehicles (AUVs), and their supporting infrastructure play a major role in the collection of oceanographic data. To make new discoveries and improve our overall understanding of the ocean, scientists must make use of these platforms by implementing effective monitoring and sampling techniques to study ocean upwelling, tidal mixing, and other ocean processes. Effective observation and continual monitoring of a dynamic system as complex as the ocean cannot be done with one instrument in a fixed location. A more practical approach is to deploy a collection of static and mobile sensors, where the information gleaned from the acquired data is distributed across the network. Additionally, orchestrating a multisensor, long-term deployment with a high volume of distributed data involves a robust, rapid, and cost-effective communication network. Connecting all of these components, which form an aquatic robotic system, in synchro- nous operation can greatly assist the scientists in improving our overall understanding of the complex ocean environment.
This paper describes a small underwater robot designed for experiments with sensor-actuator netwo... more This paper describes a small underwater robot designed for experiments with sensor-actuator networks. The robot is based on the mote platform, which is used extensively in the sensor networking community as an experimental testbed.
Faculty of Built Environment and Engineering School of Engineering Systems, Oct 1, 2009
These databases contain citations from different subsets of available publications and different ... more These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science generally from 1980 onwards.
La presente invention concerne un systeme d'eclairage lumineux a distance (10) comportant un ... more La presente invention concerne un systeme d'eclairage lumineux a distance (10) comportant un sequenceur de systeme d'eclairage (18), permettant d'assurer une repartition sequentielle des signaux lumineux pour plusieurs dispositifs de repartition d'eclairage. Une source lumineuse (12) fournit au sequenceur d'eclairage (18) des signaux focalises (44, 46). Le sequenceur d'eclairage (18) comprend un scanner optique (22) et une commande electronique permettant de diriger de maniere selective les signaux lumineux (44, 46) vers des fibres optiques individuelles (20), appartenant a un systeme de repartition a fibres optiques. Les fibres optiques (20) assure le couplage des signaux lumineux aux dispositifs de repartition d'eclairage, ce qui permet d'obtenir un eclairage sequentiel conforme a un modele desire.
This paper describes a small underwater robot designed for experiments with sensor-actuator netwo... more This paper describes a small underwater robot designed for experiments with sensor-actuator networks. The robot is based on the mote platform, which is used extensively in the sensor networking community as an experimental testbed. The components and construction of the robot are described. Preliminary tests of depth regulation and temperature measurement are reported and analyzed.
Autonomous Underwater Vehicles (AUVs) are revolutionizing oceanography. Most high-endurance and l... more Autonomous Underwater Vehicles (AUVs) are revolutionizing oceanography. Most high-endurance and long-range AUVs rely on satellite phones as their primary communications interface during missions for data/command telemetry due to its global coverage. Satellite phone (e.g., Iridium) expenses can make up a significant portion of an AUV's operating budget during long missions. Slocum gliders are a type of AUV that provide unprecedented longevity in scientific missions for data collection. Here we describe a minimally-intrusive modification to the existing hardware and an accompanying software system that provides an alternative robust disruption-tolerant communications framework enabling cost-effective glider operation in coastal regions. Our framework is specifically designed to address multiple-AUV operations in a region covered by multiple networked base-stations equipped with radio modems. We provide a system overview and preliminary evaluation results from three field deployments using a glider. We believe that this framework can be extended to reduce operational costs for other AUVs during coastal operations.
A wireless network of buoys, two autonomous robotic boats, and an autonomous tethered vertical pr... more A wireless network of buoys, two autonomous robotic boats, and an autonomous tethered vertical profiling system were used to characterize phytoplankton dynamics and spatiotemporal changes in chemical and physical forcing factors in a small montane lake (Lake Fulmor, Idyllwild, California). Three deployments each year were conducted in 2005 and 2006 to examine seasonal changes in the structure of the lake and phytoplankton assemblage, as well as fine-scale temporal and spatial variations. The buoys yielded fine-scale temporal patterns of in situ fluorescence and temperature, while the vertical profiling system yielded two-dimensional, cross-sectional profiles of several parameters. The autonomous vehicles provided information on fluorescence and corresponding temperature patterns across the surface of the lake. Average, lake-wide chlorophyll concentrations increased 10fold seasonally, and strong anoxia developed in the hypolimnion during the summer. The latter process dramatically affected vertical chemical gradients in the 5 m water column of the lake. Small-scale spatial (,1 m) and temporal (minutes) heterogeneity in fluorescence were surprisingly large. These variations were due predominantly to vertical mixing of the phytoplankton assemblage and to phytoplankton vertical migratory behavior. Large peaks in fluorescence at 0.5-m occurred at very short time intervals (minutes) during all deployments, and appeared to be due to upward mixing of deeper dwelling eukaryotic phytoplankton during early-midsummer , or downward mixing of surface-associated cyanobacteria during late summer.
This paper describes the design, development, and initial application of a sensor-actuated networ... more This paper describes the design, development, and initial application of a sensor-actuated network for sensing and sampling microbial communities in aquatic ecosystems. The network consists of ten stationary buoys and one mobile robotic boat for real-time, in situ measurements and analysis of chemical and physical factors governing the abundance and dynamics of microorganisms at biologically relevant spatiotemporal scales. The goal of the network is to obtain high-resolution information on the spatial and temporal distributions of plankton assemblages and concomitant environmental parameters in aquatic environments using the in situ presence afforded by the network and to make possible network-enabled robotic sampling of hydrographic features of interest. This work constitutes advances in (1) real-time observing in aquatic ecosystems and (2) sensor actuated sampling for biological analysis.
ABSTRACT More than 70% of our earth is covered by water, yet we have explored less than 5% of the... more ABSTRACT More than 70% of our earth is covered by water, yet we have explored less than 5% of the aquatic environment. Aquatic robots, such as autono- mous underwater vehicles (AUVs), and their supporting infrastructure play a major role in the collection of oceanographic data. To make new discoveries and improve our overall understanding of the ocean, scientists must make use of these platforms by implementing effective monitoring and sampling techniques to study ocean upwelling, tidal mixing, and other ocean processes. Effective observation and continual monitoring of a dynamic system as complex as the ocean cannot be done with one instrument in a fixed location. A more practical approach is to deploy a collection of static and mobile sensors, where the information gleaned from the acquired data is distributed across the network. Additionally, orchestrating a multisensor, long-term deployment with a high volume of distributed data involves a robust, rapid, and cost-effective communication network. Connecting all of these components, which form an aquatic robotic system, in synchro- nous operation can greatly assist the scientists in improving our overall understanding of the complex ocean environment.
This paper describes a small underwater robot designed for experiments with sensor-actuator netwo... more This paper describes a small underwater robot designed for experiments with sensor-actuator networks. The robot is based on the mote platform, which is used extensively in the sensor networking community as an experimental testbed.
Faculty of Built Environment and Engineering School of Engineering Systems, Oct 1, 2009
These databases contain citations from different subsets of available publications and different ... more These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science generally from 1980 onwards.
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Papers by Carl Oberg