Pub Date : 2019-06-01DOI: 10.1109/OCEANSE.2019.8867310
Dhomé Ulysse, Rolleberg Niklas, Kuttenkeuler Jakob
This paper presents the development and experimental evaluation of a self-steering mechanism for an autonomous sailing vessel. The steering mechanism is designed and tailored to relief the commonly used electro-mechanical steering during majority of the mission by the use of pure mechanical coupling between the self-trimming rig and the rudder. This significantly reduces the need for electric power for steering at constant apparent wind angle. Added to the steering, a two-layer navigation system is proposed for path-planning and navigation with algorithms tailored for low-power, low-memory microcontroller. We present experimental results from a total of 19 days of autonomous sailing in Stockholm’s Archipelago. The experiments enabled us to compare the sailing performance with both active and self-steering systems for different apparent wind angles. On average, the active steering keeps a heading within ±5.1◦ of the target while the self-steering is able to maintain the heading within ±8.1◦ of the target. Another conclusion that can be drawn is that the apparent wind angle doesn’t influence the steering performance.
{"title":"Energy Efficient Self-Steering Mechanism for an Autonomous Sailing Vessel","authors":"Dhomé Ulysse, Rolleberg Niklas, Kuttenkeuler Jakob","doi":"10.1109/OCEANSE.2019.8867310","DOIUrl":"https://doi.org/10.1109/OCEANSE.2019.8867310","url":null,"abstract":"This paper presents the development and experimental evaluation of a self-steering mechanism for an autonomous sailing vessel. The steering mechanism is designed and tailored to relief the commonly used electro-mechanical steering during majority of the mission by the use of pure mechanical coupling between the self-trimming rig and the rudder. This significantly reduces the need for electric power for steering at constant apparent wind angle. Added to the steering, a two-layer navigation system is proposed for path-planning and navigation with algorithms tailored for low-power, low-memory microcontroller. We present experimental results from a total of 19 days of autonomous sailing in Stockholm’s Archipelago. The experiments enabled us to compare the sailing performance with both active and self-steering systems for different apparent wind angles. On average, the active steering keeps a heading within ±5.1◦ of the target while the self-steering is able to maintain the heading within ±8.1◦ of the target. Another conclusion that can be drawn is that the apparent wind angle doesn’t influence the steering performance.","PeriodicalId":375793,"journal":{"name":"OCEANS 2019 - Marseille","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117117067","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 : 2019-06-01DOI: 10.1109/OCEANSE.2019.8867393
P. Lei, Shuqing Ma, Wenke Wang, Le Li, Zemin Zhou, Yu Chen
In this paper, our study is motivated by the fact that it is not always clear what the placement of the multiple passive sensors giving the best tracking performance for the underwater targets of interest might be. To account for the issue, posterior Cramér-Rao lower bound (PCRLB) is utilized, which provides a measure of the optimal achievable accuracy of the target state estimation. To derive the recursive Fisher information matrix (FIM) and PCRLB for multisensor multitarget state estimation in an uncertain ocean environment, we address the impact of the uncertain propagation, which is ignored by the previously researches. It is demonstrated that the propagation uncertainty and target tracking results play important roles in the FIM and PCRLB. Moreover, the general framework for integrated target tracking and sensor placement is also proposed.
{"title":"Posterior Cramér-Rao Lower Bound for Multiple Passive Sensors in an Uncertain Ocean Environment","authors":"P. Lei, Shuqing Ma, Wenke Wang, Le Li, Zemin Zhou, Yu Chen","doi":"10.1109/OCEANSE.2019.8867393","DOIUrl":"https://doi.org/10.1109/OCEANSE.2019.8867393","url":null,"abstract":"In this paper, our study is motivated by the fact that it is not always clear what the placement of the multiple passive sensors giving the best tracking performance for the underwater targets of interest might be. To account for the issue, posterior Cramér-Rao lower bound (PCRLB) is utilized, which provides a measure of the optimal achievable accuracy of the target state estimation. To derive the recursive Fisher information matrix (FIM) and PCRLB for multisensor multitarget state estimation in an uncertain ocean environment, we address the impact of the uncertain propagation, which is ignored by the previously researches. It is demonstrated that the propagation uncertainty and target tracking results play important roles in the FIM and PCRLB. Moreover, the general framework for integrated target tracking and sensor placement is also proposed.","PeriodicalId":375793,"journal":{"name":"OCEANS 2019 - Marseille","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117135748","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 : 2019-06-01DOI: 10.1109/OCEANSE.2019.8867369
Shuyi Wu, Shuche Wang, Zhiqiang He, K. Niu, Y. Rong
An accurate and efficient channel and impulsive noise estimation is an important step in underwater acoustic (UA) orthogonal frequency-division multiplexing systems. We propose an approximate message passing (AMP) algorithm for channel and impulsive noise estimation. In particular, we model the distribution of the channel impulse response and impulsive noise as a Gaussian mixture, which is the prior information for the AMP algorithm. The proposed algorithm is evaluated through numerical simulations and real data collected during a UA communication experiment conducted in December 2015 in the estuary of the Swan River, Western Australia. The simulation and experimental results show that compared with existing approaches, the proposed algorithm has a better performance.
{"title":"An Approximate Message Passing Algorithm for Channel and Impulsive Noise Estimation in Underwater Acoustic OFDM Systems","authors":"Shuyi Wu, Shuche Wang, Zhiqiang He, K. Niu, Y. Rong","doi":"10.1109/OCEANSE.2019.8867369","DOIUrl":"https://doi.org/10.1109/OCEANSE.2019.8867369","url":null,"abstract":"An accurate and efficient channel and impulsive noise estimation is an important step in underwater acoustic (UA) orthogonal frequency-division multiplexing systems. We propose an approximate message passing (AMP) algorithm for channel and impulsive noise estimation. In particular, we model the distribution of the channel impulse response and impulsive noise as a Gaussian mixture, which is the prior information for the AMP algorithm. The proposed algorithm is evaluated through numerical simulations and real data collected during a UA communication experiment conducted in December 2015 in the estuary of the Swan River, Western Australia. The simulation and experimental results show that compared with existing approaches, the proposed algorithm has a better performance.","PeriodicalId":375793,"journal":{"name":"OCEANS 2019 - Marseille","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121079862","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 : 2019-06-01DOI: 10.1109/OCEANSE.2019.8867292
Xuan Li, Xiaochuan Ma
In underwater environment, the low speed target recognition has been a challenge problem. A design for underwater objects identification is suggested in this paper. The construction can be used in harbor surveillance and ocean environment inspection. Utilizing super-resolution beamforming, the distinctions between the low-speed object (such as buoy or low speed AUV) and the beacon can be observed in spatial-temporal spectrum. Corresponding to the features of power differences and spatial spectrum variance in vertical direction, the low-speed object can be separated from beacon. The data from lake experiment is dealt with and illustrate the method.
{"title":"Underwater objects classifier based on super-resolution spatial spectrum variance","authors":"Xuan Li, Xiaochuan Ma","doi":"10.1109/OCEANSE.2019.8867292","DOIUrl":"https://doi.org/10.1109/OCEANSE.2019.8867292","url":null,"abstract":"In underwater environment, the low speed target recognition has been a challenge problem. A design for underwater objects identification is suggested in this paper. The construction can be used in harbor surveillance and ocean environment inspection. Utilizing super-resolution beamforming, the distinctions between the low-speed object (such as buoy or low speed AUV) and the beacon can be observed in spatial-temporal spectrum. Corresponding to the features of power differences and spatial spectrum variance in vertical direction, the low-speed object can be separated from beacon. The data from lake experiment is dealt with and illustrate the method.","PeriodicalId":375793,"journal":{"name":"OCEANS 2019 - Marseille","volume":"167 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124888609","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 : 2019-06-01DOI: 10.1109/OCEANSE.2019.8867081
M. Lucas, M. L. Menn, Arnaud David, J. Sagot, P. Poli, Kai Herklotz, M. Belbéoch, A. O'carroll
The on-going efforts to improved remote sensing data quality, and in particular the retrieval of Sea Surface temperature though the use of the radiometer underlined the need for higher quality in situ calibrated reference temperature (O’Carroll 2008). This let to a first attempt at designing and deploying improved drifting buoys within the framework of the DBCP HR-SST Pilot Project. These improvements included an improved location accuracy through the use of GPS, an improved in situ temperature resolution (0.01 K) and the finally a new binary format to ensure that the improved resolution temperature was correctly fed into the WMO GTS system.
{"title":"A New Type of DBCP compliant drifting Buoy: the SVP-BRST","authors":"M. Lucas, M. L. Menn, Arnaud David, J. Sagot, P. Poli, Kai Herklotz, M. Belbéoch, A. O'carroll","doi":"10.1109/OCEANSE.2019.8867081","DOIUrl":"https://doi.org/10.1109/OCEANSE.2019.8867081","url":null,"abstract":"The on-going efforts to improved remote sensing data quality, and in particular the retrieval of Sea Surface temperature though the use of the radiometer underlined the need for higher quality in situ calibrated reference temperature (O’Carroll 2008). This let to a first attempt at designing and deploying improved drifting buoys within the framework of the DBCP HR-SST Pilot Project. These improvements included an improved location accuracy through the use of GPS, an improved in situ temperature resolution (0.01 K) and the finally a new binary format to ensure that the improved resolution temperature was correctly fed into the WMO GTS system.","PeriodicalId":375793,"journal":{"name":"OCEANS 2019 - Marseille","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126092835","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 : 2019-06-01DOI: 10.1109/OCEANSE.2019.8867583
Céline Drouet, N. Cellier
One way to increase the operability of the naval platform is to predict its future motions. To predict these future motions it is necessary to know the future environmental conditions and more especially the waves incoming to the naval platform. To know the incoming waves it is necessary to observe them upstream with an optical or electromagnetic sensor and propagate them down to the future position of the naval platform. This knowledge of the future waves can be decisive for engaging critical phase of maritime operations, like the launch and recovery of helicopters and drones…Among the observed waves, some of them called "dangerous waves" can induce high ship motions which carry on a cancellation of the launch or land of a helicopter. Dangerous is not about tsunami or rogue waves here, but rather relatively energetic waves (higher, steeper than average) that can transfer kinetic energy to the ship. Often these waves occur in groups. The aim of this article is to present a simple and pragmatic method based on an energetic approach to find these "dangerous waves" out of the observed surface by the waves sensors and propagate them up to a desired position. Results of the propagation of the identified "dangerous waves" are presented for simulated surface elevation of open ocean, obtained by using the software HOS-ocean. (Abstract)
{"title":"Observation and propagation of wave groups to improve the proceedings of the maritime operation","authors":"Céline Drouet, N. Cellier","doi":"10.1109/OCEANSE.2019.8867583","DOIUrl":"https://doi.org/10.1109/OCEANSE.2019.8867583","url":null,"abstract":"One way to increase the operability of the naval platform is to predict its future motions. To predict these future motions it is necessary to know the future environmental conditions and more especially the waves incoming to the naval platform. To know the incoming waves it is necessary to observe them upstream with an optical or electromagnetic sensor and propagate them down to the future position of the naval platform. This knowledge of the future waves can be decisive for engaging critical phase of maritime operations, like the launch and recovery of helicopters and drones…Among the observed waves, some of them called \"dangerous waves\" can induce high ship motions which carry on a cancellation of the launch or land of a helicopter. Dangerous is not about tsunami or rogue waves here, but rather relatively energetic waves (higher, steeper than average) that can transfer kinetic energy to the ship. Often these waves occur in groups. The aim of this article is to present a simple and pragmatic method based on an energetic approach to find these \"dangerous waves\" out of the observed surface by the waves sensors and propagate them up to a desired position. Results of the propagation of the identified \"dangerous waves\" are presented for simulated surface elevation of open ocean, obtained by using the software HOS-ocean. (Abstract)","PeriodicalId":375793,"journal":{"name":"OCEANS 2019 - Marseille","volume":"221 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123286714","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 : 2019-06-01DOI: 10.1109/OCEANSE.2019.8867579
Huan Wang, X. Du, Baoshou Zhang
In recent years, with an increasing interest in the underwater wave glider, which is propelled by converting the ocean wave energy into forward thrust through flapping multi-foil, the flapping-foil aerodynamics has become an important and popular topic of research in the biomimetic field. However, due to the complex marine environment, the wave motion frequency is low and uncontrollable, and the wave amplitude and frequency are non-constant, which make the underwater multi-wing fluttering flow field of the aircraft unsteady. Therefore, it is crucial to study the propulsive characteristics of underwater flapping multi-foil under different conditions. In this paper, hydrodynamics calculation model is built based on the Reynolds-averaged Navier–Stokes (RANS) equation and Realizable model. Two dimensional (2D) NACA foils are applied to establish the hydrodynamic calculation model of flapping multi-foil. The foils are assumed to undergo a combined translational and rotational motion. The unstructured grid was generates by Ansys ICEM. CFD Commercial software Fluent is applied to solve the fluid dynamic characteristics of the flapping multi-foil under various conditions. The results show that flapping multi-foil can produce higher propulsion than a single flapping foil, the interaction of the multi-foil wake was found advantageous for propulsion, it can produce higher propulsion when the distance between the foils is shorter. In this paper, results also show the influence of different factors to the propulsion, which provides a meaningful reference for developing underwater flapping multi-foil vehicle.
{"title":"Propulsive Performance Analysis of Underwater Flapping Multi-foil","authors":"Huan Wang, X. Du, Baoshou Zhang","doi":"10.1109/OCEANSE.2019.8867579","DOIUrl":"https://doi.org/10.1109/OCEANSE.2019.8867579","url":null,"abstract":"In recent years, with an increasing interest in the underwater wave glider, which is propelled by converting the ocean wave energy into forward thrust through flapping multi-foil, the flapping-foil aerodynamics has become an important and popular topic of research in the biomimetic field. However, due to the complex marine environment, the wave motion frequency is low and uncontrollable, and the wave amplitude and frequency are non-constant, which make the underwater multi-wing fluttering flow field of the aircraft unsteady. Therefore, it is crucial to study the propulsive characteristics of underwater flapping multi-foil under different conditions. In this paper, hydrodynamics calculation model is built based on the Reynolds-averaged Navier–Stokes (RANS) equation and Realizable model. Two dimensional (2D) NACA foils are applied to establish the hydrodynamic calculation model of flapping multi-foil. The foils are assumed to undergo a combined translational and rotational motion. The unstructured grid was generates by Ansys ICEM. CFD Commercial software Fluent is applied to solve the fluid dynamic characteristics of the flapping multi-foil under various conditions. The results show that flapping multi-foil can produce higher propulsion than a single flapping foil, the interaction of the multi-foil wake was found advantageous for propulsion, it can produce higher propulsion when the distance between the foils is shorter. In this paper, results also show the influence of different factors to the propulsion, which provides a meaningful reference for developing underwater flapping multi-foil vehicle.","PeriodicalId":375793,"journal":{"name":"OCEANS 2019 - Marseille","volume":"22 7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125688559","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 : 2019-06-01DOI: 10.1109/OCEANSE.2019.8867516
Joyce O'Grady, Nigel J. Kent, I. Maguire, P. McGinnity, E. Jennings, F. Regan
Recent developments in the area of low cost optical analysers has enabled rapid, reliable and robust analysis of water nutrient levels, such as phosphate, in water systems. Herein, describes an enhancement study of a previously demonstrated lab- on-a-disc (LOAD) centrifugal microfluidic device for the detection of phosphate in freshwater. The LOAD device utilizes a microfluidic sample processing to enable high precision metering and reagent mixing, followed by colorimetric analysis (at 880 nm) of the resultant complex. A customisable and complementary, in-house analysis system was also developed to enhance user interaction and enable rapid analysis. This analysis system delivers both disc centrifugation and automated colourimetric detection of the LOAD device, with recording of data transmitted via PC interface. The aim of this study is to maintain the same level of sensitivity of the current[1] system with a reduced pathlength. The limit of detection (LOD) and limit of quantification (LOQ) for this new revised system are as follows: The blackened chip obtained the best sensitivity with an LOD and LOQ of 6 and 19 μg L−1 respectively, followed by the P80 roughened chip which achieved 13 and 38 μg L−1, these results will be discussed further in this paper.The previously demonstrated microfluidic platform demonstrated an optical path length detection of 75 mm for optimal detectability, resulting in low quantity of sample testing per disc. This work details the optimisation of the disc design through a reduction of path length, therefore increasing the number of test replications on-disc by two-fold and a reduction in reagent consumption, whilst maintaining the same sensitivity using photo-enhancement techniques. The photo-enhancement techniques described in this paper utilize detection channel surface modifications, e.g. coatings and refractive index modification. These assist in significantly improving the signal-to-noise (S/N) with increased transmittance, hence increasing the overall sensitivity that can be achieved using the system. This piece of work focuses on the optical improvement using surface modification strategies in detection enhancement.
{"title":"In-channel modifications for improved optical detection of phosphate in a microfluidic chip design","authors":"Joyce O'Grady, Nigel J. Kent, I. Maguire, P. McGinnity, E. Jennings, F. Regan","doi":"10.1109/OCEANSE.2019.8867516","DOIUrl":"https://doi.org/10.1109/OCEANSE.2019.8867516","url":null,"abstract":"Recent developments in the area of low cost optical analysers has enabled rapid, reliable and robust analysis of water nutrient levels, such as phosphate, in water systems. Herein, describes an enhancement study of a previously demonstrated lab- on-a-disc (LOAD) centrifugal microfluidic device for the detection of phosphate in freshwater. The LOAD device utilizes a microfluidic sample processing to enable high precision metering and reagent mixing, followed by colorimetric analysis (at 880 nm) of the resultant complex. A customisable and complementary, in-house analysis system was also developed to enhance user interaction and enable rapid analysis. This analysis system delivers both disc centrifugation and automated colourimetric detection of the LOAD device, with recording of data transmitted via PC interface. The aim of this study is to maintain the same level of sensitivity of the current[1] system with a reduced pathlength. The limit of detection (LOD) and limit of quantification (LOQ) for this new revised system are as follows: The blackened chip obtained the best sensitivity with an LOD and LOQ of 6 and 19 μg L−1 respectively, followed by the P80 roughened chip which achieved 13 and 38 μg L−1, these results will be discussed further in this paper.The previously demonstrated microfluidic platform demonstrated an optical path length detection of 75 mm for optimal detectability, resulting in low quantity of sample testing per disc. This work details the optimisation of the disc design through a reduction of path length, therefore increasing the number of test replications on-disc by two-fold and a reduction in reagent consumption, whilst maintaining the same sensitivity using photo-enhancement techniques. The photo-enhancement techniques described in this paper utilize detection channel surface modifications, e.g. coatings and refractive index modification. These assist in significantly improving the signal-to-noise (S/N) with increased transmittance, hence increasing the overall sensitivity that can be achieved using the system. This piece of work focuses on the optical improvement using surface modification strategies in detection enhancement.","PeriodicalId":375793,"journal":{"name":"OCEANS 2019 - Marseille","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122525450","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 : 2019-06-01DOI: 10.1109/OCEANSE.2019.8867368
R. Yan, Fubin Zhang, Huihui Chen
MEMS-IMU has the characteristics of small size and low cost. It can greatly reduce the cost when applied to underwater navigation and positioning system. However, MEMS-IMU has lower precision and poorer stability, especially MEMS magnetometers are more susceptible to the surrounding magnetic field environment. Therefore, it is of great significance to study a stable and effective calibration method for magnetometers. In this paper, by analyzing the existing magnetometer calibration methods, namely the ellipsoid fitting method and the dot product invariance method, an improved method namely multi-constraint calibration based on two is proposed. Based on the three basic properties of the geomagnetic field, the error equation of the multi-constraint calibration method is established, the nonlinear optimization objective function is obtained from the error equation, and the nonlinear target optimization function is solved by the Levenberg-Marquardt (L-M) method to obtain the calibration parameters. The error is compensated to obtain an ideal magnetometer output, which improves the accuracy of the AUV(Autonomous Underwater Vehicle) underwater navigation system. The simulation results show that the multi-constraint calibration method has obvious advantages compared with the ellipsoid fitting method and the dot product invariant method in solving the calibration parameters.
{"title":"A MEMS-based Magnetometer Calibration Approach in AUV Navigation System","authors":"R. Yan, Fubin Zhang, Huihui Chen","doi":"10.1109/OCEANSE.2019.8867368","DOIUrl":"https://doi.org/10.1109/OCEANSE.2019.8867368","url":null,"abstract":"MEMS-IMU has the characteristics of small size and low cost. It can greatly reduce the cost when applied to underwater navigation and positioning system. However, MEMS-IMU has lower precision and poorer stability, especially MEMS magnetometers are more susceptible to the surrounding magnetic field environment. Therefore, it is of great significance to study a stable and effective calibration method for magnetometers. In this paper, by analyzing the existing magnetometer calibration methods, namely the ellipsoid fitting method and the dot product invariance method, an improved method namely multi-constraint calibration based on two is proposed. Based on the three basic properties of the geomagnetic field, the error equation of the multi-constraint calibration method is established, the nonlinear optimization objective function is obtained from the error equation, and the nonlinear target optimization function is solved by the Levenberg-Marquardt (L-M) method to obtain the calibration parameters. The error is compensated to obtain an ideal magnetometer output, which improves the accuracy of the AUV(Autonomous Underwater Vehicle) underwater navigation system. The simulation results show that the multi-constraint calibration method has obvious advantages compared with the ellipsoid fitting method and the dot product invariant method in solving the calibration parameters.","PeriodicalId":375793,"journal":{"name":"OCEANS 2019 - Marseille","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122150727","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 : 2019-06-01DOI: 10.1109/OCEANSE.2019.8867584
M. Pinheiro, T. Miranda, Vasco Ferreira, E. Pereira, I. Valente, Fábio Cruz, D. Maslov
Earth systems are nowadays on the verge of radical disruptions, whether due to unprecedented demographic pressures or as a result of the current complexity of global systems. Climate Changes, ecosystems unbalances, natural resources depletion, pollution, extreme events, natural catastrophes, humanized overpopulated environments, as well as economical turbulences, represent more than ever, very uncertain terms of an equation that is difficult to balance. Novel procedures are essential to make use of local and global information that is nowadays available from multiple sources, to produce intelligible and actionable models for sustainable development, in particular for the oceans protection, the main support of human life on earth. An example of this procedures is the Oceans Accounts (OA) framework that aims at integrating the biophysical information, measure ecosystem services, track and measure the changes on the ecosystems and link all this data to economic and human activity within a given spatial area. This work presents a novel approach that uses spatial modeling techniques capable of dealing with limited and discrete data, such as Geostatistics. These spatial techniques, combined with remote sensing, can provide a sound background of information for the implementation and leverage of the Oceans Accounts framework. Moreover, an emphasis will be given to the application of the OA framework to marine protected areas (MPA’s) with an identification of the main gaps regarding the cycle of collecting, processing and integrating social, environmental and economic data. The main focus will be on enabling the next generation of decision support systems to support design and impact assessment of alternative engineering solutions for marine contexts, such as energy harvesting and offshore platforms or aquaculture, in the context of blue economy, as well as marine planning and economic activities regulation.
{"title":"From decision-making to Oceans Accounts: a case study","authors":"M. Pinheiro, T. Miranda, Vasco Ferreira, E. Pereira, I. Valente, Fábio Cruz, D. Maslov","doi":"10.1109/OCEANSE.2019.8867584","DOIUrl":"https://doi.org/10.1109/OCEANSE.2019.8867584","url":null,"abstract":"Earth systems are nowadays on the verge of radical disruptions, whether due to unprecedented demographic pressures or as a result of the current complexity of global systems. Climate Changes, ecosystems unbalances, natural resources depletion, pollution, extreme events, natural catastrophes, humanized overpopulated environments, as well as economical turbulences, represent more than ever, very uncertain terms of an equation that is difficult to balance. Novel procedures are essential to make use of local and global information that is nowadays available from multiple sources, to produce intelligible and actionable models for sustainable development, in particular for the oceans protection, the main support of human life on earth. An example of this procedures is the Oceans Accounts (OA) framework that aims at integrating the biophysical information, measure ecosystem services, track and measure the changes on the ecosystems and link all this data to economic and human activity within a given spatial area. This work presents a novel approach that uses spatial modeling techniques capable of dealing with limited and discrete data, such as Geostatistics. These spatial techniques, combined with remote sensing, can provide a sound background of information for the implementation and leverage of the Oceans Accounts framework. Moreover, an emphasis will be given to the application of the OA framework to marine protected areas (MPA’s) with an identification of the main gaps regarding the cycle of collecting, processing and integrating social, environmental and economic data. The main focus will be on enabling the next generation of decision support systems to support design and impact assessment of alternative engineering solutions for marine contexts, such as energy harvesting and offshore platforms or aquaculture, in the context of blue economy, as well as marine planning and economic activities regulation.","PeriodicalId":375793,"journal":{"name":"OCEANS 2019 - Marseille","volume":"1 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116767644","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}
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