{"title":"A reduced order observer for underwater manipulators using potentiometers for position measurements","authors":"M. Erlic, W.-s. Lu","doi":"10.1109/OCEANS.1993.326111","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326111","url":null,"abstract":"In this paper an improved manipulator joint velocity observer is presented which is reduced in its order. The observer provides a smooth velocity estimate to be used by a trajectory tracking controller. The observer, controller and manipulator form a system where the observer error as well as the position and velocity tracking errors tend to zero asymptotically. The proposed observer is compared to numerical differentiation plus filtering as a means to provide a velocity signal which is used in control. When considering joint position signals corrupted with measurement noise, it is found that the proposed observer is superior in its performance compared to numerical differentiation plus filtering.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123072439","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}
{"title":"Comparisons of model predictions for the total amplitude probability density function with measurements from SAXON FPN","authors":"D. Thompson, B. Gotwols","doi":"10.1109/OCEANS.1993.326058","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326058","url":null,"abstract":"Simulations of the amplitude probability density function of the electromagnetic field backscattered from the ocean surface in the North Sea are compared with measurements at Ka, Ku and X-band taken during the SAXON FPN experiment. Good agreement is found at both 20/spl deg/ and 45/spl deg/ incidence after accounting for hydrodynamic modulation of the short scale waves by the long waves.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124469422","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}
{"title":"Ambiguity surface manifestation of downslope converted noise sources","authors":"Jean‐Marie Q. D. Tran, W. Hodgkiss","doi":"10.1109/OCEANS.1993.326218","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326218","url":null,"abstract":"Deals with the manifestation of downslope converted continental shelf noise sources (primarily ships) in the matched-field processor (MFP) ambiguity surface. Of interest is how noise sources outside the range of interest leak into the ambiguity surface through the sidelobe structure of the effective MFP beam (or cell) pattern. This study is carried out with simulations using the parabolic equation model. A shallow 18 Hz source is assumed deployed at various locations on the continental slope, 1750 km from a 1000 m long vertical line array. The MFP search window extends in range across 500 km and in depth down to 1000 m. Shallow sources on the slope show up in the MFP ambiguity surface as deep peaks when downslope conversion takes place. Shallow sources at locations on the slope or in deep water adjacent to the slope where downslope conversion does not take place, appear in the MFP ambiguity surface as shallow sources.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121762020","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}
{"title":"SOTS: a Sun-based system for oceanographic analysis","authors":"M. S. Moustafa, G. Hebenstreit, M. Mandelberg","doi":"10.1109/OCEANS.1993.326210","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326210","url":null,"abstract":"The Sun-based oceanographic analysis package, SOTS (SASEA On The Sun), was developed to provide near-real-time analysis of oceanographic and acoustic conditions during large-scale at-sea experiments and underwater system development tests. SOTS can be ship-based, land-based, or both. The system enables scientists participating in such tests to quickly evaluate the oceanographic/acoustic conditions present and to respond to changes in conditions or differences between the expected and actual environments. SOTS capabilities include profile editing, database utilities, statistical tools, and graphical displays. Because of the many oceanographic and acoustic data analysis capabilities and applications that exist in the SOTS system potential applications include oceanographic site assessments, modeling and analysis of data fields, generation of 3D sound speed fields, and acoustic tomography.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114068453","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}
{"title":"Development of a towed vehicle for physical and chemical measurement in the ocean upper mixed layer","authors":"W. Koterayama, T. Akamatsu","doi":"10.1109/OCEANS.1993.326239","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326239","url":null,"abstract":"A motion controllable towed vehicle housing an acoustic Doppler current profiler, CO/sub 2/ analyzer and sensors for other physical and chemical measurements in the upper ocean mixed layer is being developed. The length of the towed vehicle is 3.84 m, breadth is 2.26 m, height 1.4 m and weight in air is 1000 kg, and the maximum submersible depth is designed as 200 m which is enough to research the ocean mixed layer. The data obtained are sent through a towing cable and analyzed by computer in real time on the mother ship.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125210263","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}
{"title":"Slope and hydrodynamic modulation of radar scatter from the sea","authors":"V. Hesany, R. Moore, S. Haimov","doi":"10.1109/OCEANS.1993.326203","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326203","url":null,"abstract":"Microwave backscatter from the ocean surface is largely due to Bragg scattering from short surface ripples. Modulation of the signal results from changes in the local angle of incidence as the local slope changes, and from variations in Bragg ripple amplitude. The slope (tilt) modulation can be modeled as a memoryless nonlinear system. The hydrodynamic modulation results from a nonuniform distribution of the amplitude of the small-scale ripples over the large-scale waves. For azimuthally traveling waves the hydrodynamic modulation dominates, while for waves propagating in other directions, both tilt and hydrodynamic modulation are significant. The authors developed a 35-GHz radar vector slope gauge (VSG) to measure the orthogonal components of the surface slopes within the radar footprint. Simultaneous measurements of the surface slope and radar cross section permit determination of the relative contribution of slope and hydrodynamic modulations to the overall fluctuation of the radar signal. The authors present a method for separating effects due to the surface tilting from hydrodynamic effects. They include a sample result based on this approach with data from the SAXON-FPN experiment in November, 1990.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129444770","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}
{"title":"Research on an oscillating fin propulsion control system","authors":"I. Yamamoto, Y. Terada, T. Nagamatu, Y. Imaizumi","doi":"10.1109/OCEANS.1993.326197","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326197","url":null,"abstract":"The purpose of this paper is to describe the feasibility research on an oscillating fin propulsion control system as a vehicle actuator. The system was designed and constructed in order to be combined with ship models. Tank cruising tests were conducted to confirm the system's feasibility. As a result, several advantages were found. The effectiveness of a neural network was successfully proven for an advanced control system.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124642244","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}
{"title":"Passive acoustical measurements of scale, probability, and intensity of wave breaking","authors":"Li Ding, D. Farmer","doi":"10.1109/OCEANS.1993.326090","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326090","url":null,"abstract":"New observations of breaking surface waves have recently been acquired with a novel acoustic instrument during the Surface Wave Processes Program. Several breaking wave parameters have been measured. This paper focuses on breaking scale, breaking probability, and radiated acoustic power from breaking waves. The breaking scale is derived from the travel speed of breaking waves. It is found that the mean scale is 46%-75% of the dominant wave phase speed, and that the radiated acoustic power is well correlated with the mean scale. The breaking probability is found to be consistent with a linear statistical model. Potential application of these results in estimating wave energy dissipation is discussed.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130538737","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}
{"title":"Cloud masking for CoastWatch satellite imagery","authors":"E. Maturi, W. Pichel","doi":"10.1109/OCEANS.1993.326122","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326122","url":null,"abstract":"A cloud mask program is available for masking out all clouds present on CoastWatch satellite imagery products. CoastWatch satellite imagery are operational NOAA polar-satellite 1 km Advanced Very High Resolution Radiometer (AVHRR) data that are remapped for designated U.S. coastal regions. Sea surface temperature imagery is one of the current CoastWatch products; however, the product contains cloudy pixels. A cloud mask product is necessary to determine cloud free areas for sea surface temperature identification. The Clouds from AVHRR (CLAVR) cloud detection algorithm is being tested on both day and night AVHRR imagery. An explanation of the cloud masking tests and examples of their application to the analysis of sea surface temperature imagery for the coastal U.S. on a near-real time basis are presented.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130954161","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}
{"title":"Stability of an underwater work platform suspended from an unstable reference","authors":"R. Bostelman, James, Albus","doi":"10.1109/OCEANS.1993.326114","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326114","url":null,"abstract":"A work platform suspended by six cables and controlled by six winches located on a vessel, can precisely control the position, velocity, and force of tools, grippers, and machinery in all six degrees of freedom (x, y, z, roll, pitch, and yaw) while the vessel is moving due to sea surface conditions. Based on the Robocrane, the platform can be maneuvered via operator controls (e.g. a joystick) for doing work without disturbance of the sea bottom by controlling the cable tensions and buoyancy of the work platform. Large forces and torques can be exerted with the work platform while being controlled from a remote position. Many applications are possible: from underwater laying/repair to construction, in other than mild weather conditions.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131591609","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}