Pub Date : 2014-09-01DOI: 10.1109/OCEANS.2014.7003105
Giovanni Toso, I. Calabrese, F. Favaro, Loris Brolo, P. Casari, M. Zorzi
In the context of a collaboration with the NATO STO Centre for Maritime Research and Experimentation (CMRE), during the CommsNet'13 campaign we deployed a large set of experiments aimed at measuring some network statistics for three protocols for remote data retrieval in underwater networks, namely Uw-Polling (a controlled access scheme), MSUN (a source routing approach with support for mobility) and U-Fetch (a scheme based on two hierarchical levels of controlled access). The main idea behind the trial was to perform some experiments in order to get a hands-on practical experience with the protocols, evaluate their performance in a systematic way, and observe which specific features of a real world experiment can alter the performance of the protocols, compared to a computer simulation. The results obtained help understand the protocols better and can be used to refine their design and improve their performance. The experiments are run thanks to the flexibility of the DESERT Underwater framework, and managed through a newly designed acoustic remote control framework called RECORDS.
{"title":"Testing network protocols via the DESERT underwater framework: The CommsNet'13 experience","authors":"Giovanni Toso, I. Calabrese, F. Favaro, Loris Brolo, P. Casari, M. Zorzi","doi":"10.1109/OCEANS.2014.7003105","DOIUrl":"https://doi.org/10.1109/OCEANS.2014.7003105","url":null,"abstract":"In the context of a collaboration with the NATO STO Centre for Maritime Research and Experimentation (CMRE), during the CommsNet'13 campaign we deployed a large set of experiments aimed at measuring some network statistics for three protocols for remote data retrieval in underwater networks, namely Uw-Polling (a controlled access scheme), MSUN (a source routing approach with support for mobility) and U-Fetch (a scheme based on two hierarchical levels of controlled access). The main idea behind the trial was to perform some experiments in order to get a hands-on practical experience with the protocols, evaluate their performance in a systematic way, and observe which specific features of a real world experiment can alter the performance of the protocols, compared to a computer simulation. The results obtained help understand the protocols better and can be used to refine their design and improve their performance. The experiments are run thanks to the flexibility of the DESERT Underwater framework, and managed through a newly designed acoustic remote control framework called RECORDS.","PeriodicalId":368693,"journal":{"name":"2014 Oceans - St. John's","volume":"34 12","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133106726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-09-01DOI: 10.1109/OCEANS.2014.7003219
J. Singleton, R. Bachmayer, B. de Young
Observation of the ocean environment is key to attaining the knowledge and understanding required to predict its evolving state and to respond to its condition. However, manned observation and collection of high resolution oceanographic data over long periods of time is both expensive and hazardous. Various autonomous profiling platforms have been developed to address the issue but there still exists the opportunity to develop efficient, robust, and reliable, low cost platforms to provide the data. In this paper we present the development of a new autonomous profiling system for areas along the continental shelf. The proposed design is a moored vehicle that will profile the water column by controlling the predetermined ascent/descent routine of an instrumentation payload though the use of a buoyancy engine. One of its unique features is the use of a subsea mooring to secure the profiler while still providing the ability to profile the entire water column and make a telemetry link. The profiler has two modes of dynamic behavior during its profile. One mode is similar to that of a profiler which follows a mooring line, while the other mode is similar to a winched profiler.
{"title":"Development of a new autonomous underwater moored mobile profiler","authors":"J. Singleton, R. Bachmayer, B. de Young","doi":"10.1109/OCEANS.2014.7003219","DOIUrl":"https://doi.org/10.1109/OCEANS.2014.7003219","url":null,"abstract":"Observation of the ocean environment is key to attaining the knowledge and understanding required to predict its evolving state and to respond to its condition. However, manned observation and collection of high resolution oceanographic data over long periods of time is both expensive and hazardous. Various autonomous profiling platforms have been developed to address the issue but there still exists the opportunity to develop efficient, robust, and reliable, low cost platforms to provide the data. In this paper we present the development of a new autonomous profiling system for areas along the continental shelf. The proposed design is a moored vehicle that will profile the water column by controlling the predetermined ascent/descent routine of an instrumentation payload though the use of a buoyancy engine. One of its unique features is the use of a subsea mooring to secure the profiler while still providing the ability to profile the entire water column and make a telemetry link. The profiler has two modes of dynamic behavior during its profile. One mode is similar to that of a profiler which follows a mooring line, while the other mode is similar to a winched profiler.","PeriodicalId":368693,"journal":{"name":"2014 Oceans - St. John's","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115781806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-09-01DOI: 10.1109/OCEANS.2014.7003226
S. Williams, R. Pomerleau, R. Hasanen
The next generation smart port power supply has been designed to provide new features and improved performance. These ports allow for the software based configuration of instrument port voltages and communications protocols providing the greatest possible flexibility in instrument to junction box interfacing. This article describes the benefits of the software configurable smart port implementation discussed in [1]. Next generation improvements made to the line insulation monitor, in-line noise filtering and power supply efficiency based off lessons learned and feedback on the initial NEPTUNE project are also discussed.
{"title":"Software configurable smart ports in seafloor networks","authors":"S. Williams, R. Pomerleau, R. Hasanen","doi":"10.1109/OCEANS.2014.7003226","DOIUrl":"https://doi.org/10.1109/OCEANS.2014.7003226","url":null,"abstract":"The next generation smart port power supply has been designed to provide new features and improved performance. These ports allow for the software based configuration of instrument port voltages and communications protocols providing the greatest possible flexibility in instrument to junction box interfacing. This article describes the benefits of the software configurable smart port implementation discussed in [1]. Next generation improvements made to the line insulation monitor, in-line noise filtering and power supply efficiency based off lessons learned and feedback on the initial NEPTUNE project are also discussed.","PeriodicalId":368693,"journal":{"name":"2014 Oceans - St. John's","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125168033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-09-01DOI: 10.1109/OCEANS.2014.7003242
C. Merz, K. Main
As fishing has become more industrialized and wild fish stocks increasingly depleted, aquaculture production has grown rapidly to address the shortfalls in capture fisheries and limitations to long-term aquaculture success. One such shortfall is the need to produce a suitable, sustainable, substitute for the capture fishery derived fish meal and oil based fish feeds currently in use, while maintaining the human protein requirements and health benefits of Long Chain (LC) omega-3 oils in farmed fish products. Fish derive the LC omega-3 oils from the food they consume, which ultimately comes from lower trophic level primary producers like microalgae. Using Integrated Aquaculture System (IAS) principles and practices, microalgae (diatoms) can be raised and processed directly for their Algal/Single Cell Oils (SCO), protein, and nutrients. Besides the use as an aquaculture feedstock, microalgae have been investigated for biofuel production because of higher photosynthetic efficiency, higher biomass production, and faster growth compared to other terrestrial energy crops. SCO based carbon-neutral renewable liquid biofuel solutions are currently under investigation but suffer from high production costs. Liquid biofuels have been considered to displace non-renewable, petroleum-derived transport fuels of limited availability which contribute to climate change via greenhouse gas (GHG) emissions. The current high cost constraint of SCO production could be alleviated through explored water-energy-food nexus synergies between the aquaculture and biofuels sector with a concentration on innovations in microalgae/SCO production, harvesting, and processing technologies. Interdisciplinary collaborations between engineers, biologists and chemists are essential for their successful development.
{"title":"Microalgae (diatom) production — The aquaculture and biofuel nexus","authors":"C. Merz, K. Main","doi":"10.1109/OCEANS.2014.7003242","DOIUrl":"https://doi.org/10.1109/OCEANS.2014.7003242","url":null,"abstract":"As fishing has become more industrialized and wild fish stocks increasingly depleted, aquaculture production has grown rapidly to address the shortfalls in capture fisheries and limitations to long-term aquaculture success. One such shortfall is the need to produce a suitable, sustainable, substitute for the capture fishery derived fish meal and oil based fish feeds currently in use, while maintaining the human protein requirements and health benefits of Long Chain (LC) omega-3 oils in farmed fish products. Fish derive the LC omega-3 oils from the food they consume, which ultimately comes from lower trophic level primary producers like microalgae. Using Integrated Aquaculture System (IAS) principles and practices, microalgae (diatoms) can be raised and processed directly for their Algal/Single Cell Oils (SCO), protein, and nutrients. Besides the use as an aquaculture feedstock, microalgae have been investigated for biofuel production because of higher photosynthetic efficiency, higher biomass production, and faster growth compared to other terrestrial energy crops. SCO based carbon-neutral renewable liquid biofuel solutions are currently under investigation but suffer from high production costs. Liquid biofuels have been considered to displace non-renewable, petroleum-derived transport fuels of limited availability which contribute to climate change via greenhouse gas (GHG) emissions. The current high cost constraint of SCO production could be alleviated through explored water-energy-food nexus synergies between the aquaculture and biofuels sector with a concentration on innovations in microalgae/SCO production, harvesting, and processing technologies. Interdisciplinary collaborations between engineers, biologists and chemists are essential for their successful development.","PeriodicalId":368693,"journal":{"name":"2014 Oceans - St. John's","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132080456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-09-01DOI: 10.1109/OCEANS.2014.7003140
Sarah E. Houts, S. Rock
Providing a series of images of a site over time with a survey-class AUV presents numerous challenges, particularly in the process of getting close to rugged terrain with a motion-constrained vehicle in an uncertain environment. To deal with this, a baseline approach presented in previous work by the authors plans spline-based trajectories based on an a priori map of the terrain, allowing for improved performance over purely reactive control schemes. This paper extends that approach to account for uncertainty in the environment, both in the knowledge of the terrain and the motion of the vehicle, providing additional robustness and safety, while minimizing the potential loss in performance. The trajectory optimization approach is demonstrated over simulated terrain.
{"title":"Trajectory planning for motion-constrained AUVs in uncertain environments","authors":"Sarah E. Houts, S. Rock","doi":"10.1109/OCEANS.2014.7003140","DOIUrl":"https://doi.org/10.1109/OCEANS.2014.7003140","url":null,"abstract":"Providing a series of images of a site over time with a survey-class AUV presents numerous challenges, particularly in the process of getting close to rugged terrain with a motion-constrained vehicle in an uncertain environment. To deal with this, a baseline approach presented in previous work by the authors plans spline-based trajectories based on an a priori map of the terrain, allowing for improved performance over purely reactive control schemes. This paper extends that approach to account for uncertainty in the environment, both in the knowledge of the terrain and the motion of the vehicle, providing additional robustness and safety, while minimizing the potential loss in performance. The trajectory optimization approach is demonstrated over simulated terrain.","PeriodicalId":368693,"journal":{"name":"2014 Oceans - St. John's","volume":"353 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132305234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-09-01DOI: 10.1109/OCEANS.2014.7003288
Xin Cheng, Azizur Rahman
A liquefied natural gas (LNG) carrier is designed to transport LNG over a long distance. During transportation, the leakage of boil-off gas (BOG) along with poor ventilation can pose an explosion risk. The traditional method for dealing with the BOG is to burn the gas to power the ship. As an alternative method, re-liquefaction plants on board re-liquefy the vapours back to the cargo tanks. This project will characterize the technical issues associated with fire protection in a confined space where LNG boil-off re-liquefaction takes place and will demonstrate what the appropriate ventilation rate in an emergency is. In addition, the CFD software (ANSYS CFX) is applied to simulate the ventilation and burning of boil-off gas in the on board re-liquefaction plant to ensure the safety of the cargo tanks for the worst case scenario. The traditional method for dealing with the boil-off gas (BOG) on board an LNG carrier is to burn the gas to power the ship. As an alternative method, re-liquefaction plants on board re-liquefy the vapour back to the cargo tanks [1]. In the last few years, the introduction of LNG re-liquefaction systems has given ship owners a choice of fuels and provides engine redundancy. Nevertheless, flammable natural gas is processed in both methods. Due to the inherent properties of a ship's structure, the re-liquefaction system, gas combustion unit, pipelines, etc. are located in the space enclosed under the deck. Under certain circumstances the leakage of natural gas, along with poor ventilation, can pose an explosion risk. Unfortunately, limited industry codes have been developed for fire protection in the cabin where the innovative LNG re-liquefaction system is located. The purpose of this project is to demonstrate the leaking and burning of boil-off gas in the on board re-liquefaction plant to ensure the safety of the cargo tanks for the worst case scenario by using CFD simulation software.
{"title":"BOG ventilation and combustion in re-liquefaction plants of LNG carriers","authors":"Xin Cheng, Azizur Rahman","doi":"10.1109/OCEANS.2014.7003288","DOIUrl":"https://doi.org/10.1109/OCEANS.2014.7003288","url":null,"abstract":"A liquefied natural gas (LNG) carrier is designed to transport LNG over a long distance. During transportation, the leakage of boil-off gas (BOG) along with poor ventilation can pose an explosion risk. The traditional method for dealing with the BOG is to burn the gas to power the ship. As an alternative method, re-liquefaction plants on board re-liquefy the vapours back to the cargo tanks. This project will characterize the technical issues associated with fire protection in a confined space where LNG boil-off re-liquefaction takes place and will demonstrate what the appropriate ventilation rate in an emergency is. In addition, the CFD software (ANSYS CFX) is applied to simulate the ventilation and burning of boil-off gas in the on board re-liquefaction plant to ensure the safety of the cargo tanks for the worst case scenario. The traditional method for dealing with the boil-off gas (BOG) on board an LNG carrier is to burn the gas to power the ship. As an alternative method, re-liquefaction plants on board re-liquefy the vapour back to the cargo tanks [1]. In the last few years, the introduction of LNG re-liquefaction systems has given ship owners a choice of fuels and provides engine redundancy. Nevertheless, flammable natural gas is processed in both methods. Due to the inherent properties of a ship's structure, the re-liquefaction system, gas combustion unit, pipelines, etc. are located in the space enclosed under the deck. Under certain circumstances the leakage of natural gas, along with poor ventilation, can pose an explosion risk. Unfortunately, limited industry codes have been developed for fire protection in the cabin where the innovative LNG re-liquefaction system is located. The purpose of this project is to demonstrate the leaking and burning of boil-off gas in the on board re-liquefaction plant to ensure the safety of the cargo tanks for the worst case scenario by using CFD simulation software.","PeriodicalId":368693,"journal":{"name":"2014 Oceans - St. John's","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133882805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-09-01DOI: 10.1109/OCEANS.2014.7003099
Jeffrey M. Walls, R. Eustice
This paper reports on an algorithm for planning a practical trajectory for a surface vehicle that provides range measurements to an autonomous underwater vehicle (AUV). We consider server-client cooperative localization in which a server vehicle provides relative range constraints to minimize the uncertainty of a client vehicle. Our approach assumes the nominal client mission plan is available and draws potential server trajectories from a set of parameterized trajectory classes. We provide a comparative evaluation over several simulations, for both a single client and multiple clients, demonstrating that our algorithm computes operationally practical server paths and performs well relative to existing planning frameworks.
{"title":"Toward informative planning for cooperative underwater localization","authors":"Jeffrey M. Walls, R. Eustice","doi":"10.1109/OCEANS.2014.7003099","DOIUrl":"https://doi.org/10.1109/OCEANS.2014.7003099","url":null,"abstract":"This paper reports on an algorithm for planning a practical trajectory for a surface vehicle that provides range measurements to an autonomous underwater vehicle (AUV). We consider server-client cooperative localization in which a server vehicle provides relative range constraints to minimize the uncertainty of a client vehicle. Our approach assumes the nominal client mission plan is available and draws potential server trajectories from a set of parameterized trajectory classes. We provide a comparative evaluation over several simulations, for both a single client and multiple clients, demonstrating that our algorithm computes operationally practical server paths and performs well relative to existing planning frameworks.","PeriodicalId":368693,"journal":{"name":"2014 Oceans - St. John's","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115955331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-09-01DOI: 10.1109/OCEANS.2014.7003070
Sarah E. Webster, Craig M. Lee, J. Gobat
This paper presents an under-ice acoustic navigation system developed for Seaglider, a buoyancy-driven autonomous underwater vehicle (AUV), and post-processed navigation results from one of fourteen glider deployments between 2006 and 2014 in Davis Strait. Seagliders typically receive all geolocation information from global positioning system (GPS) signals received while they are at the surface, and perform dead reckoning while underwater. Extended under-ice deployments, where access to GPS is denied due to the inability of the glider to surface, require an alternative source of geolocation information. In the deployments described herein, geolocation information is provided by range measurements from mooring-mounted acoustic navigation sources at fixed, known locations. In this paper we describe the navigation system used in Davis Strait and present navigation results from a six degree-of-freedom Kalman filter using post-processed navigation data.
{"title":"Preliminary results in under-ice acoustic navigation for seagliders in Davis Strait","authors":"Sarah E. Webster, Craig M. Lee, J. Gobat","doi":"10.1109/OCEANS.2014.7003070","DOIUrl":"https://doi.org/10.1109/OCEANS.2014.7003070","url":null,"abstract":"This paper presents an under-ice acoustic navigation system developed for Seaglider, a buoyancy-driven autonomous underwater vehicle (AUV), and post-processed navigation results from one of fourteen glider deployments between 2006 and 2014 in Davis Strait. Seagliders typically receive all geolocation information from global positioning system (GPS) signals received while they are at the surface, and perform dead reckoning while underwater. Extended under-ice deployments, where access to GPS is denied due to the inability of the glider to surface, require an alternative source of geolocation information. In the deployments described herein, geolocation information is provided by range measurements from mooring-mounted acoustic navigation sources at fixed, known locations. In this paper we describe the navigation system used in Davis Strait and present navigation results from a six degree-of-freedom Kalman filter using post-processed navigation data.","PeriodicalId":368693,"journal":{"name":"2014 Oceans - St. John's","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115614841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-09-01DOI: 10.1109/OCEANS.2014.7003188
Romain Michalec, C. Pradalier
We introduce our first work on terrain-based navigation of autonomous underwater vehicles using sidescan sonars and sidescan sonar maps. It consists in estimating the state of the vehicle from its inertial proprioceptions and sidescan exteroceptions using a particle filter. The novelty is the use of sidescan acoustic perceptions and sidescan sonar maps instead of single-beam bottom-looking acoustic perceptions and bathymetric maps. Also, the approach is not landmark-based. Our first simulations, although conducted under simplifying hypotheses, show that the approach is valid and may be applied to more complex situations.
{"title":"Sidescan sonar aided inertial drift compensation in autonomous underwater vehicles","authors":"Romain Michalec, C. Pradalier","doi":"10.1109/OCEANS.2014.7003188","DOIUrl":"https://doi.org/10.1109/OCEANS.2014.7003188","url":null,"abstract":"We introduce our first work on terrain-based navigation of autonomous underwater vehicles using sidescan sonars and sidescan sonar maps. It consists in estimating the state of the vehicle from its inertial proprioceptions and sidescan exteroceptions using a particle filter. The novelty is the use of sidescan acoustic perceptions and sidescan sonar maps instead of single-beam bottom-looking acoustic perceptions and bathymetric maps. Also, the approach is not landmark-based. Our first simulations, although conducted under simplifying hypotheses, show that the approach is valid and may be applied to more complex situations.","PeriodicalId":368693,"journal":{"name":"2014 Oceans - St. John's","volume":"120 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123761625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-09-01DOI: 10.1109/OCEANS.2014.7003198
A. Williams
Testing and calibrating a current meter is part of bringing a new design into production. The opportunity to demonstrate this has been provided by the re-engining of the acoustic differential travel-time current meter, MAVS (Modular Acoustic Velocity Sensor) [1]. In 2012, the supplier of the controller used by MAVS announced End of Life for their product. A search for a suitable replacement took a year, and in summer 2013, the CF2 by Persistor [2] was selected. The interface board to adapt the CF2 to the footprint of its predecessor on the MAVS mother board was designed in midsummer 2013 and laid out in the fall of 2013. Circuit boards were etched in late fall of 2013 and the first prototype was tested in January 2014. A significant trial of the interface board was to adapt the 3.3v CF2 to the 5v logic of MAVS with minimum impact on the well-tested and validated MAVS. This required level shifter circuits for both up shifting and down shifting on the interface board. These were tested without the new code required to run the program of measurement. Power switching imposes another constraint since it is necessary to turn off the 5v logic between measurement bursts while the 3.3v CF2 is still running. An up shifter circuit requires that the output never be lower voltage than the input but without the 5v logic powered there is an issue, solved for now by a voltage limiting Schottky diode to protect the up shifter when powered down. The consequences on the powered down 5v logic have yet to be tested.
{"title":"Current meter performance with CF2 controller","authors":"A. Williams","doi":"10.1109/OCEANS.2014.7003198","DOIUrl":"https://doi.org/10.1109/OCEANS.2014.7003198","url":null,"abstract":"Testing and calibrating a current meter is part of bringing a new design into production. The opportunity to demonstrate this has been provided by the re-engining of the acoustic differential travel-time current meter, MAVS (Modular Acoustic Velocity Sensor) [1]. In 2012, the supplier of the controller used by MAVS announced End of Life for their product. A search for a suitable replacement took a year, and in summer 2013, the CF2 by Persistor [2] was selected. The interface board to adapt the CF2 to the footprint of its predecessor on the MAVS mother board was designed in midsummer 2013 and laid out in the fall of 2013. Circuit boards were etched in late fall of 2013 and the first prototype was tested in January 2014. A significant trial of the interface board was to adapt the 3.3v CF2 to the 5v logic of MAVS with minimum impact on the well-tested and validated MAVS. This required level shifter circuits for both up shifting and down shifting on the interface board. These were tested without the new code required to run the program of measurement. Power switching imposes another constraint since it is necessary to turn off the 5v logic between measurement bursts while the 3.3v CF2 is still running. An up shifter circuit requires that the output never be lower voltage than the input but without the 5v logic powered there is an issue, solved for now by a voltage limiting Schottky diode to protect the up shifter when powered down. The consequences on the powered down 5v logic have yet to be tested.","PeriodicalId":368693,"journal":{"name":"2014 Oceans - St. John's","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124284183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：