Pub Date : 2014-09-01DOI: 10.1109/OCEANS.2014.7003100
Bang-hyun Kim, H. Shim, B. Jun, Pan-Mook Lee
This paper presents a communication protocol among operating programs for the CR200, which is 200m-class subsea walking robot with six legs. The number of operating programs is twelve. We have developed six essential programs, which exchange data using designed message protocol through Ethernet. The inter-program communication protocol includes message frame form, message type, transmission process, reception process, and communication sequence. The message frame is divided into header area and data area. The size of header area is two bytes and the length of data area is variable. First byte of header is start-of-frame delimiter, next two bytes indicates the length of data area, and last byte is for message type. There is no error check area because Ethernet communication protocol basically supports error check. Transmission process and reception process varies depending on message type. Some programs only run after valid interaction with other program by specified communication sequence. The protocol mechanism is simple but it was enough to operate the CR200. We successfully finished basin test of the CR200 in April 2014. Subsequently, the CR200 deployed in Sewol ferry disaster site and it supported search operation for three weeks.
{"title":"Inter-program communication protocol for operation of six-legged subsea walking robot CR200","authors":"Bang-hyun Kim, H. Shim, B. Jun, Pan-Mook Lee","doi":"10.1109/OCEANS.2014.7003100","DOIUrl":"https://doi.org/10.1109/OCEANS.2014.7003100","url":null,"abstract":"This paper presents a communication protocol among operating programs for the CR200, which is 200m-class subsea walking robot with six legs. The number of operating programs is twelve. We have developed six essential programs, which exchange data using designed message protocol through Ethernet. The inter-program communication protocol includes message frame form, message type, transmission process, reception process, and communication sequence. The message frame is divided into header area and data area. The size of header area is two bytes and the length of data area is variable. First byte of header is start-of-frame delimiter, next two bytes indicates the length of data area, and last byte is for message type. There is no error check area because Ethernet communication protocol basically supports error check. Transmission process and reception process varies depending on message type. Some programs only run after valid interaction with other program by specified communication sequence. The protocol mechanism is simple but it was enough to operate the CR200. We successfully finished basin test of the CR200 in April 2014. Subsequently, the CR200 deployed in Sewol ferry disaster site and it supported search operation for three weeks.","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":"125212041","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.2014.7003088
G. Frost, D. Lane
An application for offline Reinforcement Learning in the underwater domain is proposed. We present and evaluate the integration of the Q-learning algorithm into an Autonomous Underwater Vehicle (AUV) for learning the action-value function in simulation. Three separate experiments are presented. The first compares two search policies: the ε - least visited, and random action, with respect to convergence time. The second experiment presents the effect of the learning discount factor, gamma, on the convergence time of the ε - least visited search policy. The final experiment is to validate the use of a policy learnt offline on a real AUV. This learning phase occurs offline within the continuous simulation environment which had been discretized into a grid-world learning problem. Presented results show the system's convergence to a global optimal solution whilst following both sub-optimal policies during simulation. Future work is introduced, after discussion of our results, to enable the system to be used in a real world application. The results presented, therefore, form the basis for future comparative analysis of the necessary improvements such as function approximation of the state space.
{"title":"Evaluation of Q-learning for search and inspect missions using underwater vehicles","authors":"G. Frost, D. Lane","doi":"10.1109/OCEANS.2014.7003088","DOIUrl":"https://doi.org/10.1109/OCEANS.2014.7003088","url":null,"abstract":"An application for offline Reinforcement Learning in the underwater domain is proposed. We present and evaluate the integration of the Q-learning algorithm into an Autonomous Underwater Vehicle (AUV) for learning the action-value function in simulation. Three separate experiments are presented. The first compares two search policies: the ε - least visited, and random action, with respect to convergence time. The second experiment presents the effect of the learning discount factor, gamma, on the convergence time of the ε - least visited search policy. The final experiment is to validate the use of a policy learnt offline on a real AUV. This learning phase occurs offline within the continuous simulation environment which had been discretized into a grid-world learning problem. Presented results show the system's convergence to a global optimal solution whilst following both sub-optimal policies during simulation. Future work is introduced, after discussion of our results, to enable the system to be used in a real world application. The results presented, therefore, form the basis for future comparative analysis of the necessary improvements such as function approximation of the state space.","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":"125419239","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.2014.7003191
V. Filaretov, D. Yukhimets, E. Mursalimov, A. Scherbatyuk, I. Tuphanov
Some results of a new tracking control method investigation using an autonomous underwater vehicle (AUV) is considered in this paper. This method involves additional loops for automatic program signals generation in AUV control system (CS). The work of these additional loops provides the AUV motion along the desired spatial trajectory with high velocity and desired accuracy. The features of the proposed CS realization and results of experimental researches are presented.
{"title":"Some marine trial results of a new method for AUV trajectory motion control","authors":"V. Filaretov, D. Yukhimets, E. Mursalimov, A. Scherbatyuk, I. Tuphanov","doi":"10.1109/OCEANS.2014.7003191","DOIUrl":"https://doi.org/10.1109/OCEANS.2014.7003191","url":null,"abstract":"Some results of a new tracking control method investigation using an autonomous underwater vehicle (AUV) is considered in this paper. This method involves additional loops for automatic program signals generation in AUV control system (CS). The work of these additional loops provides the AUV motion along the desired spatial trajectory with high velocity and desired accuracy. The features of the proposed CS realization and results of experimental researches are presented.","PeriodicalId":368693,"journal":{"name":"2014 Oceans - St. John's","volume":"31 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":"125613019","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.2014.7003142
Ken Sooknanan, J. Doyle, C. Lordan, James Wilson, A. Kokaram, D. Corrigan
Harvesting the commercially significant lobster, Nephrops norvegicus, is a multimillion dollar industry in Europe. Stock assessment is essential for maintaining this activity but it is conducted by manually inspecting hours of underwater surveillance videos. To improve this tedious process, we propose an automated procedure. This procedure uses mosaics for detecting the Nephrops, which improves visibility and reduces the tedious video inspection process to the browsing of a single image. In addition to this novel application approach, key contributions are made for handling the difficult lighting conditions in these kinds of videos. Mosaics are built using 1-10 minutes of footage and candidate Nephrops regions are selected using image segmentation based on local image contrast and colour features. A K-Nearest Neighbour classifier is then used to select the respective Nephrops from these candidate regions. Our final decision accuracy at 87.5% recall and precision shows a corresponding 31.5% and 79.4% improvement compared with previous work [1].
{"title":"Mosaics for Nephrops detection in underwater survey videos","authors":"Ken Sooknanan, J. Doyle, C. Lordan, James Wilson, A. Kokaram, D. Corrigan","doi":"10.1109/OCEANS.2014.7003142","DOIUrl":"https://doi.org/10.1109/OCEANS.2014.7003142","url":null,"abstract":"Harvesting the commercially significant lobster, Nephrops norvegicus, is a multimillion dollar industry in Europe. Stock assessment is essential for maintaining this activity but it is conducted by manually inspecting hours of underwater surveillance videos. To improve this tedious process, we propose an automated procedure. This procedure uses mosaics for detecting the Nephrops, which improves visibility and reduces the tedious video inspection process to the browsing of a single image. In addition to this novel application approach, key contributions are made for handling the difficult lighting conditions in these kinds of videos. Mosaics are built using 1-10 minutes of footage and candidate Nephrops regions are selected using image segmentation based on local image contrast and colour features. A K-Nearest Neighbour classifier is then used to select the respective Nephrops from these candidate regions. Our final decision accuracy at 87.5% recall and precision shows a corresponding 31.5% and 79.4% improvement compared with previous work [1].","PeriodicalId":368693,"journal":{"name":"2014 Oceans - St. John's","volume":"33 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":"124049882","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.2014.7003276
Henrique P. P. Pereira, C. Ribeiro, F. Carvalho, Luiz F. Moraes, R. M. Campos
The transmission of metocean data collected in real-time is essential for marine operations. Due to the high cost associated with satellite communication, the complete characterization of sea state is impaired. The moderns single boards computers, enables the development of dedicated modules for processing and quality control of the collected series, allowing to perform more complex tasks and transmitting additional information relevant to the characterization of sea states. The main goals of this work is to increase the reliability of real-time data, transmitted by heave-pitch-roll buoys and verify the efficiency of a single board computer to execute the traditional wave processing by Longuet-Higgins and DAAT, including automatic quality control. This new wave data processing system allows a deeper evaluation of the information that can characterize a sea state of a time series that was stored inside the buoy and was not transmitted in real-time.
{"title":"Improvement of directional wave information and quality control before real-time telemetry of heave-pitch-roll metocean buoys","authors":"Henrique P. P. Pereira, C. Ribeiro, F. Carvalho, Luiz F. Moraes, R. M. Campos","doi":"10.1109/OCEANS.2014.7003276","DOIUrl":"https://doi.org/10.1109/OCEANS.2014.7003276","url":null,"abstract":"The transmission of metocean data collected in real-time is essential for marine operations. Due to the high cost associated with satellite communication, the complete characterization of sea state is impaired. The moderns single boards computers, enables the development of dedicated modules for processing and quality control of the collected series, allowing to perform more complex tasks and transmitting additional information relevant to the characterization of sea states. The main goals of this work is to increase the reliability of real-time data, transmitted by heave-pitch-roll buoys and verify the efficiency of a single board computer to execute the traditional wave processing by Longuet-Higgins and DAAT, including automatic quality control. This new wave data processing system allows a deeper evaluation of the information that can characterize a sea state of a time series that was stored inside the buoy and was not transmitted in real-time.","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":"129114101","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.2014.7003042
T. Yeu, Sukmin Yoon, Sup Hong, Hyung-Woo Kim, Chang-ho Lee, Jin-Ho Kim, Cheon-hong Min, Jong-Su Choi
A pilot-scale mining robot for manganese nodule has been developed by KRISO (Korea Research Institute of Ships and Ocean Engineering) in 2012. The robot consists of two unit-modules having an identical mechanical and hydraulic configuration. Each unit module has two tracks, two pick-up devices with attitude control devices, two crushers, one discharging pump, and hydraulic system. In 2013, Sea-trial has been performed at 130m depth in the east sea of South Korea. To strictly keep and follow the pre-defined complex path with a constant forward speed, steering characteristics of the mining robot are required. To know the characteristics of the robot, steering performance test was executed with appointed steering ratios. Also, for the reliable driving of the robot, the velocity pattern of four-columns tracks is determined by numerical simulation. To actuate track motor as a commanded velocity, PI controller is designed from system identification method and gain tuning rule.
{"title":"Steering performance test of underwater mining robot","authors":"T. Yeu, Sukmin Yoon, Sup Hong, Hyung-Woo Kim, Chang-ho Lee, Jin-Ho Kim, Cheon-hong Min, Jong-Su Choi","doi":"10.1109/OCEANS.2014.7003042","DOIUrl":"https://doi.org/10.1109/OCEANS.2014.7003042","url":null,"abstract":"A pilot-scale mining robot for manganese nodule has been developed by KRISO (Korea Research Institute of Ships and Ocean Engineering) in 2012. The robot consists of two unit-modules having an identical mechanical and hydraulic configuration. Each unit module has two tracks, two pick-up devices with attitude control devices, two crushers, one discharging pump, and hydraulic system. In 2013, Sea-trial has been performed at 130m depth in the east sea of South Korea. To strictly keep and follow the pre-defined complex path with a constant forward speed, steering characteristics of the mining robot are required. To know the characteristics of the robot, steering performance test was executed with appointed steering ratios. Also, for the reliable driving of the robot, the velocity pattern of four-columns tracks is determined by numerical simulation. To actuate track motor as a commanded velocity, PI controller is designed from system identification method and gain tuning rule.","PeriodicalId":368693,"journal":{"name":"2014 Oceans - St. John's","volume":"28 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":"129684414","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.2014.7003272
A. Goodney, Young H. Cho
Ocean acoustic tomography is a traveltime tomography technique that can be used to map the sound-speed field in a given region of water. Ocean acoustic tomography and other travel-time tomography techniques use the time-of-flight for a signal sent between a sender and receiver to infer information about the conditions of the region under study. Traditionally, such techniques assume that for each sender-receiver pair, one data point can be obtained from the time-of-flight: the average speed-of-sound along the path. In this paper we introduce multipulse acoustic tomography, a new travel-time tomography technique that uses a sequence of bi-directional pulses as the acoustic signal. By analyzing the difference in traveltime between pairs of pulses traveling in the same and opposite direction we can distribute the change in average speed-of-sound into sub-regions along the acoustic path. The result is a much more detailed picture of the distribution in speed-of-sound between a sender-receiver pair. Such a detailed distribution can be used to improve reconstruction techniques or to obtain high resolution results with fewer nodes. We present the system design and design constraints for multipluse acoustic tomography along with simulation results that show the technique can separate local speed-of-sound changes along an acoustic path from the average.
{"title":"Multipulse acoustic tomography: A new technique for mapping water temperatures","authors":"A. Goodney, Young H. Cho","doi":"10.1109/OCEANS.2014.7003272","DOIUrl":"https://doi.org/10.1109/OCEANS.2014.7003272","url":null,"abstract":"Ocean acoustic tomography is a traveltime tomography technique that can be used to map the sound-speed field in a given region of water. Ocean acoustic tomography and other travel-time tomography techniques use the time-of-flight for a signal sent between a sender and receiver to infer information about the conditions of the region under study. Traditionally, such techniques assume that for each sender-receiver pair, one data point can be obtained from the time-of-flight: the average speed-of-sound along the path. In this paper we introduce multipulse acoustic tomography, a new travel-time tomography technique that uses a sequence of bi-directional pulses as the acoustic signal. By analyzing the difference in traveltime between pairs of pulses traveling in the same and opposite direction we can distribute the change in average speed-of-sound into sub-regions along the acoustic path. The result is a much more detailed picture of the distribution in speed-of-sound between a sender-receiver pair. Such a detailed distribution can be used to improve reconstruction techniques or to obtain high resolution results with fewer nodes. We present the system design and design constraints for multipluse acoustic tomography along with simulation results that show the technique can separate local speed-of-sound changes along an acoustic path from the average.","PeriodicalId":368693,"journal":{"name":"2014 Oceans - St. John's","volume":"3 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":"129713492","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.2014.7003216
T. Bastin, Abir Zubayer, B. Veitch, A. Akinturk, Jungyong Wang, Randy Billard
Propeller wake wash has been used effectively for ice management operations for years. The main uses of propeller wake wash include clearing pack ice and broken ice from protected installations and shipping channels. A numerical model of a propeller wake has been developed to simulate the effects of the wake, or jet, on ice pieces floating on the water surface. The propeller wake is modeled using the theory of horizontal round jets as well as empirical equations derived from previous experiments. The modification of the propeller jet due to the free surface is modeled using experimental results for round jets. A dynamic model of ice piece motion is used to simulate the action of the jet on ice pieces. Model predictions are compared to experimental results of pack ice subjected to propeller wake wash. The analysis shows that the model can be used to simulate the clearing of pack ice. The model was subsequently incorporated in a real time simulator to assess its performance in 3D rendered virtual environments.
{"title":"Propeller wake wash for ice management","authors":"T. Bastin, Abir Zubayer, B. Veitch, A. Akinturk, Jungyong Wang, Randy Billard","doi":"10.1109/OCEANS.2014.7003216","DOIUrl":"https://doi.org/10.1109/OCEANS.2014.7003216","url":null,"abstract":"Propeller wake wash has been used effectively for ice management operations for years. The main uses of propeller wake wash include clearing pack ice and broken ice from protected installations and shipping channels. A numerical model of a propeller wake has been developed to simulate the effects of the wake, or jet, on ice pieces floating on the water surface. The propeller wake is modeled using the theory of horizontal round jets as well as empirical equations derived from previous experiments. The modification of the propeller jet due to the free surface is modeled using experimental results for round jets. A dynamic model of ice piece motion is used to simulate the action of the jet on ice pieces. Model predictions are compared to experimental results of pack ice subjected to propeller wake wash. The analysis shows that the model can be used to simulate the clearing of pack ice. The model was subsequently incorporated in a real time simulator to assess its performance in 3D rendered virtual environments.","PeriodicalId":368693,"journal":{"name":"2014 Oceans - St. John's","volume":"127 2 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":"129854138","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.2014.7003246
Peng Han, Zhongge Zhang, Chao Ren, Grant L. Steven
In the application of underwater target orientation using two-dimensional differential pressure vector sensors, both the elements of the vector sensors and the compensation algorithm will introduce target orientation errors. In this paper, simulation results of these target orientation errors reveal that channel response inconsistency errors contribute much more influence to the orthogonal array compared with the SNR, the target incident angle, and the unit location displacement. Based on this observation, a compensation algorithm for orientation estimation error is proposed and testing results demonstrate the efficiency of the proposed algorithm.
{"title":"Orientation error analysis and compenstation of orthogonal array with two-dimension vector sensors","authors":"Peng Han, Zhongge Zhang, Chao Ren, Grant L. Steven","doi":"10.1109/OCEANS.2014.7003246","DOIUrl":"https://doi.org/10.1109/OCEANS.2014.7003246","url":null,"abstract":"In the application of underwater target orientation using two-dimensional differential pressure vector sensors, both the elements of the vector sensors and the compensation algorithm will introduce target orientation errors. In this paper, simulation results of these target orientation errors reveal that channel response inconsistency errors contribute much more influence to the orthogonal array compared with the SNR, the target incident angle, and the unit location displacement. Based on this observation, a compensation algorithm for orientation estimation error is proposed and testing results demonstrate the efficiency of the proposed algorithm.","PeriodicalId":368693,"journal":{"name":"2014 Oceans - St. John's","volume":"2 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":"128955718","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.2014.7003232
Wayne Liu, B. D'Angelo
For resonance driven energy harvesting devices, mass considerations play a critical role in matching structural resonant frequency to flow driven Vortex Induced Vibration (VIV) frequencies for optimized vibration inputs. In this paper, we present: 1) experimental data showing how mass ratio can sustain “lock-in” effects for a cylinder oscillator in roughly 1 m/s flows and 2) analytical computations showing the effect of buoy and pendulum mass on matching resonant frequency to VIV frequency.
{"title":"Mass considerations for VIV driven cantilever beam and tethered buoy with internal pendulum","authors":"Wayne Liu, B. D'Angelo","doi":"10.1109/OCEANS.2014.7003232","DOIUrl":"https://doi.org/10.1109/OCEANS.2014.7003232","url":null,"abstract":"For resonance driven energy harvesting devices, mass considerations play a critical role in matching structural resonant frequency to flow driven Vortex Induced Vibration (VIV) frequencies for optimized vibration inputs. In this paper, we present: 1) experimental data showing how mass ratio can sustain “lock-in” effects for a cylinder oscillator in roughly 1 m/s flows and 2) analytical computations showing the effect of buoy and pendulum mass on matching resonant frequency to VIV frequency.","PeriodicalId":368693,"journal":{"name":"2014 Oceans - St. John's","volume":"23 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":"128001915","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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