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post-processing Kalman smoother for underwater vehicle navigation
Title
A post-processing Kalman smoother for underwater vehicle navigation.
Creator
Gustafson, Einar Irgens., Florida Atlantic University, An, Edgar
Abstract/Description
This thesis describes an automated post-processing tool, designed for use on navigational data gathered by Autonomous Underwater Vehicles (AUVs), developed and operated by the Department of Ocean Engineering at Florida Atlantic University. The post-processing tool consists of a 9-state complementary Kalman filter in conjunction with a Rauch-Tung-Striebel (RTS) smoothing algorithm. The Kalman filter is run forward in time to merge navigational data from an Inertial Measurement Unit (IMU), a...
Show moreThis thesis describes an automated post-processing tool, designed for use on navigational data gathered by Autonomous Underwater Vehicles (AUVs), developed and operated by the Department of Ocean Engineering at Florida Atlantic University. The post-processing tool consists of a 9-state complementary Kalman filter in conjunction with a Rauch-Tung-Striebel (RTS) smoothing algorithm. The Kalman filter is run forward in time to merge navigational data from an Inertial Measurement Unit (IMU), a Doppler Velocity Log (DVL), a magnetic compass, a GPS/DGPS system and an Ultrashort Baseline (USBL) tracking system. Subsequently, the RTS smoothing algorithm is run backwards in time to find and compensate for drift errors in dead reckoned position and compass measurement error. The post-processing tool has been implemented as a graphical user interface, designed in MATLAB. Improved accuracy in post-processed position and heading has been verified by conducting sea trials and post-processing the collected data.
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Date Issued
2001
PURL
http://purl.flvc.org/fcla/dt/12752
Subject Headings
Kalman filtering, Underwater navigation
Format
Document (PDF)
Sensor based mapping and navigation for underwater robots
Title
Sensor based mapping and navigation for underwater robots.
Creator
Scarim, Philip F., Florida Atlantic University, Steer, Barry, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
This thesis presents a mapping and navigation system intended for an unmanned untethered underwater vehicle. The system utilizes range data obtained from a time of flight sonar operating at 307KHz. The range data, along with an angle measurement of the transducer, is used to generate a simple object map (detected object and its position in two dimensions). The raw range data is filtered using an edge detection algorithm. The edge detection algorithm extracts possible corners from the acoustic...
Show moreThis thesis presents a mapping and navigation system intended for an unmanned untethered underwater vehicle. The system utilizes range data obtained from a time of flight sonar operating at 307KHz. The range data, along with an angle measurement of the transducer, is used to generate a simple object map (detected object and its position in two dimensions). The raw range data is filtered using an edge detection algorithm. The edge detection algorithm extracts possible corners from the acoustic data of the scanned environment. The output of the edge detection algorithm is sent to a confidence program. The confidence program determines which of the possible "corners", determined by the edge detection algorithm, are "actual" corners. The output of the confidence program is then used to produce the object map. This object map may be used as the input to an annotated map-builder. The output of the confidence program is then input to the navigation system. The navigation system determines the position of the vehicle relative to a detected object without any a-priori information, which may be used as an input to a path planner and an obstacle avoidance system. The experiments were carried out in a 25 x 30 foot pool and the experimental data processed on a Sun Workstation using Matlab and C generated code for post-processing of the raw acoustical data.
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Date Issued
1996
PURL
http://purl.flvc.org/fcla/dt/15263
Subject Headings
Robots, Underwater navigation
Format
Document (PDF)
Simulation of reflection tomographic images of underwater targets with the effect of vehicle motion sensing errors
Title
Simulation of reflection tomographic images of underwater targets with the effect of vehicle motion sensing errors.
Creator
Quentin, Gwendoline., Florida Atlantic University, Schock, Steven G., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
The Buried Object Scanning Sonar (BOSS) is being developed at Florida Atlantic University to image targets buried under the seabed. Tomographic images are constructed using a sequence of sonar transmissions while the vehicle is moving. This motion causes image distortion and should be measured and removed by mapping the echoes received to an absolute coordinate system. The aim of this thesis is to develop and simulate a technique for generating BOSS images that provide an accurate...
Show moreThe Buried Object Scanning Sonar (BOSS) is being developed at Florida Atlantic University to image targets buried under the seabed. Tomographic images are constructed using a sequence of sonar transmissions while the vehicle is moving. This motion causes image distortion and should be measured and removed by mapping the echoes received to an absolute coordinate system. The aim of this thesis is to develop and simulate a technique for generating BOSS images that provide an accurate representation of target shape and size, by removing vehicle motion while mapping the image pixels. Synthetic acoustic data sets are generated by convolving the auto-correlated FM transmission pulse with the impulse response of an elastic sphere. Synthetic outputs of a Doppler velocity log and a 3-axis inertial measurement unit are generated to simulate vehicle motion. Noise is added to the sensor data to show the effects of motion sensor errors on image quality.
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Date Issued
2003
PURL
http://purl.flvc.org/fcla/dt/13040
Subject Headings
Ocean tomography, Sonar, Underwater navigation
Format
Document (PDF)
Determination of horizontal motion through optical flow computations
Title
Determination of horizontal motion through optical flow computations.
Creator
Chih-Ho, Yu, Caimi, F. M., Harbor Branch Oceanographic Institute
Date Issued
1993
PURL
http://purl.flvc.org/FCLA/DT/3183679
Subject Headings
Underwater navigation, Submersibles--Automatic control
Format
Document (PDF)
Development and simulation of vertical profiling capability for FAU autonomous underwater vehicles
Title
Development and simulation of vertical profiling capability for FAU autonomous underwater vehicles.
Creator
Lin, Huaying., Florida Atlantic University, Hsu, Sam, An, Edgar, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
This thesis describes the development of a simulation environment for Autonomous Underwater Vehicles (AUVs) on UNIX platforms. AUV missions can therefore be carried out without going to the sea. The Yoyo controller, a component for AUVs is also described in this thesis. The main function of Yoyo is to control the vertical profile of an AUV while it is navigating underwater performing data collection missions. The development of the controller is done in the simulation environment. Several...
Show moreThis thesis describes the development of a simulation environment for Autonomous Underwater Vehicles (AUVs) on UNIX platforms. AUV missions can therefore be carried out without going to the sea. The Yoyo controller, a component for AUVs is also described in this thesis. The main function of Yoyo is to control the vertical profile of an AUV while it is navigating underwater performing data collection missions. The development of the controller is done in the simulation environment. Several test cases have been performed, and the test results have clearly demonstrated the successful development of the controller.
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Date Issued
1998
PURL
http://purl.flvc.org/fcla/dt/15599
Subject Headings
Oceanographic submersibles--Computer simulation, Underwater navigation
Format
Document (PDF)
Enhancement of the inertial navigation system for the Florida Atlantic University autonomous underwater vehicles
Title
Enhancement of the inertial navigation system for the Florida Atlantic University autonomous underwater vehicles.
Creator
Grenon, Gabriel Jean., Florida Atlantic University, An, Edgar
Abstract/Description
This thesis describes a new Inertial Navigation System (INS), designed for use on the latest generation of Autonomous Underwater Vehicle (AUV), the Morpheus AUVs, developed by the Department of Ocean Engineering. The INS makes use of a high precision Inertial Measurement Unit (IMU) along with a Doppler Velocity Log (DVL), a GPS/DGPS system and a flux gate magnetic compass to estimate the position of the vehicle during a mission. Extensive data processing methods are used in order to reduce...
Show moreThis thesis describes a new Inertial Navigation System (INS), designed for use on the latest generation of Autonomous Underwater Vehicle (AUV), the Morpheus AUVs, developed by the Department of Ocean Engineering. The INS makes use of a high precision Inertial Measurement Unit (IMU) along with a Doppler Velocity Log (DVL), a GPS/DGPS system and a flux gate magnetic compass to estimate the position of the vehicle during a mission. Extensive data processing methods are used in order to reduce the sources of error most critical to the navigation estimation. Accelerometers and gyroscopes are used to estimate the vehicle attitude in a complementary filter; a standard Kalman filter performs yaw rate bias estimation, whereas a second, extended Kalman filter, provides position estimation of the vehicle in real time, while also correcting for heading errors. Overall the INS is capable of providing the Morpheus with 1% navigation accuracy over an hour.
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Date Issued
2000
PURL
http://purl.flvc.org/fcla/dt/12682
Subject Headings
Oceanographic submersibles--Computer simulation, Underwater navigation
Format
Document (PDF)
Implementation of the Ocean Explorer AUV dock for use with the Morpheus AUV
Title
Implementation of the Ocean Explorer AUV dock for use with the Morpheus AUV.
Creator
Lambiotte, Joseph Clayton, Jr., Florida Atlantic University, Smith, Samuel M., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
This report highlights important aspects of previous work with the Ocean Explorer (OEX) autonomous underwater vehicle (AUV) docking system as a background. This includes short baseline navigation, the Tracking Controller, Mechanical aspects of the dock, and results of testing of the docking system for the OEX Details of the Morpheus AUV are then given along with the major concerns faced in trying to adapt the OEX dock to the Morpheus. Using computer simulation, the reaction of the Morpheus...
Show moreThis report highlights important aspects of previous work with the Ocean Explorer (OEX) autonomous underwater vehicle (AUV) docking system as a background. This includes short baseline navigation, the Tracking Controller, Mechanical aspects of the dock, and results of testing of the docking system for the OEX Details of the Morpheus AUV are then given along with the major concerns faced in trying to adapt the OEX dock to the Morpheus. Using computer simulation, the reaction of the Morpheus when it impacts the dock is explored and the results of at sea testing (the collision of the vehicle and the dock) is discussed. A stinger strength analysis of the docking components is included and finally, suggestions for future work including modifications of the existing dock as well as another docking scheme are presented.
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Date Issued
2001
PURL
http://purl.flvc.org/fcla/dt/12735
Subject Headings
Oceanographic submersibles--Computer simulation, Underwater navigation
Format
Document (PDF)
Motion Compensation of an Ultra Short Baseline Array for the Acoustic Positioning of an Underwater Vehicle for Port Operations
Title
Motion Compensation of an Ultra Short Baseline Array for the Acoustic Positioning of an Underwater Vehicle for Port Operations.
Creator
Bon, Antoine, Beaujean, Pierre-Philippe, Florida Atlantic University
Abstract/Description
A Motion Compensated (MC) Ultra Short Baseline (USBL) Acoustic Positioning System (APS) operable in shallow water and port environment has been implemented at Florida Atlantic University. Multi-tones signal modulation and log-likelihood maximization enable this APS to operate in volumes of water of less than 10 cubic meters. Standard deviations of the acoustic source elevation and azimuth estimates were computed to be 3 degrees in an 8 cubic meters test tank, and reduce to 0.9 degree in a 2...
Show moreA Motion Compensated (MC) Ultra Short Baseline (USBL) Acoustic Positioning System (APS) operable in shallow water and port environment has been implemented at Florida Atlantic University. Multi-tones signal modulation and log-likelihood maximization enable this APS to operate in volumes of water of less than 10 cubic meters. Standard deviations of the acoustic source elevation and azimuth estimates were computed to be 3 degrees in an 8 cubic meters test tank, and reduce to 0.9 degree in a 2 meters deep marina. The motion compensating system estimates the array position and orientation while merging noisy measurements from a Magnetic, Angular Rate, and Gravity (MARG) sensor and a Differential Global Positioning System (DGPS) using Kalman filters. Experiments show 0.67 and 2.67 degrees of error for the array tilt and heading estimates, and 0.74 meter for the array position estimate.
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Date Issued
2007
PURL
http://purl.flvc.org/fau/fd/FA00012507
Subject Headings
Underwater navigation, Acoustical engineering, Adaptive signal processing, Underwater acoustic telemetry
Format
Document (PDF)
Synchronous spatial array processing for underwater vehicle tracking
Title
Synchronous spatial array processing for underwater vehicle tracking.
Creator
Normand, Olivier., Florida Atlantic University, Schock, Steven G., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
Navigation of Unmanned Underwater Vehicles (UUVs) is commonly assisted in confined areas by acoustic positioning systems. The Department of Ocean Engineenng at Florida Atlantic University is developing an altemative system based on submerged modems. This thesis describes an optimal target location estimation technique using a multi-channel spatial receiver array (Millscross) used as a development tool combined with a synchronous modem and transponder network mounted on buoys and UUVs. The...
Show moreNavigation of Unmanned Underwater Vehicles (UUVs) is commonly assisted in confined areas by acoustic positioning systems. The Department of Ocean Engineenng at Florida Atlantic University is developing an altemative system based on submerged modems. This thesis describes an optimal target location estimation technique using a multi-channel spatial receiver array (Millscross) used as a development tool combined with a synchronous modem and transponder network mounted on buoys and UUVs. The Millscross provides a reference to evaluate the performance of the navigation estimator. Spatial array principles are used to develop decoding and beamforming techniques to process modem messages, enabling the end user (the UUV) to estimate in real-time its own position and navigate in space. A simulation was used to compare actual results with theory and determine the processing and decoding algorithms. These algorithms were then applied to real data to estimate the target position (direction of arrival and geodetic coordinates).
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Date Issued
2002
PURL
http://purl.flvc.org/fcla/dt/12917
Subject Headings
Underwater navigation, Underwater acoustics, Signal processing--Digital techniques
Format
Document (PDF)
Obstacle detection by a forward-looking sonar integrated in an autonomous underwater vehicle
Title
Obstacle detection by a forward-looking sonar integrated in an autonomous underwater vehicle.
Creator
Martin, Antoine., Florida Atlantic University, An, Edgar, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
This thesis describes the implementation of a commercially available forward looking sonar (FLS) in an autonomous underwater vehicle (AUV) modified for the task of reactive obstacle detection. Any obstacle lying in the vehicle's path is a potential mission-terminating threat. Inclusion of a forward looking sensor would provide valuable information to the AUV. Threat assessment and navigation would use this information in order to avoid obstacles. The system used for this project is an 8...
Show moreThis thesis describes the implementation of a commercially available forward looking sonar (FLS) in an autonomous underwater vehicle (AUV) modified for the task of reactive obstacle detection. Any obstacle lying in the vehicle's path is a potential mission-terminating threat. Inclusion of a forward looking sensor would provide valuable information to the AUV. Threat assessment and navigation would use this information in order to avoid obstacles. The system used for this project is an 8-element transducer FLS at 200 kHz. The sonar control software is done in DOS on a dedicated personal computer in a PC/104 form factor. A variable cell-size grid occupancy search method is used to detect objects in the vehicle path. This thesis describes how this sonar is used for the obstacle detection task (software), how it is integrated (hardware and network) in the AUV and what are the results obtained with the system.
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Date Issued
2000
PURL
http://purl.flvc.org/fcla/dt/12691
Subject Headings
Oceanographic submersibles--Computer simulation, Sonar, Underwater navigation
Format
Document (PDF)
Modeling and estimation for the Morpheus AUV dynamics
Title
Modeling and estimation for the Morpheus AUV dynamics.
Creator
Binois, Nicolas., Florida Atlantic University, An, Edgar
Abstract/Description
This thesis describes the determination of linear and nonlinear coefficients for the Morpheus vehicle. Added mass and nonlinear damping terms were obtained by strip-theory. These added mass coefficients were compared to the ones previously computed by boundary-integral method. Open-loop simulations were conducted using both sets of added-mass coefficients along with the damping terms, which were adjusted to fit at-sea data. A previously estimation technique for hydrodynamic coefficients has...
Show moreThis thesis describes the determination of linear and nonlinear coefficients for the Morpheus vehicle. Added mass and nonlinear damping terms were obtained by strip-theory. These added mass coefficients were compared to the ones previously computed by boundary-integral method. Open-loop simulations were conducted using both sets of added-mass coefficients along with the damping terms, which were adjusted to fit at-sea data. A previously estimation technique for hydrodynamic coefficients has been applied to the Morpheus AUV using a Kalman filter. This technique based on linearized equations of motion was tested with linear and nonlinear data generated by simulation. Steering and diving motions were considered resulting in the estimation of different sets of coefficients. Results showed that the estimated values were able to reproduce accurately the vehicle motion in the linear as well as in the nonlinear case.
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Date Issued
2003
PURL
http://purl.flvc.org/fcla/dt/12972
Subject Headings
Oceanographic submersibles--Mathematical models, Hydrodynamics, Underwater navigation
Format
Document (PDF)
Thermocline tracking using an upgraded ocean explorer autonomous underwater vehicle
Title
Thermocline tracking using an upgraded ocean explorer autonomous underwater vehicle.
Creator
Clabon, Mathieu., Florida Atlantic University, Dhanak, Manhar R.
Abstract/Description
This thesis addresses the problem of tracking a thermocline---a layer of water showing an intense vertical temperature gradient---with an Autonomous Underwater Vehicle (AUV). One of Florida Atlantic University's Ocean Explorer (OEX) AUV has been upgraded, as part of the work described here, by integration of a standard and convenient software interface, and used in several thermocline survey experiments aimed at gathering oceanographic data relevant to thermoclines. A tool that simulates the...
Show moreThis thesis addresses the problem of tracking a thermocline---a layer of water showing an intense vertical temperature gradient---with an Autonomous Underwater Vehicle (AUV). One of Florida Atlantic University's Ocean Explorer (OEX) AUV has been upgraded, as part of the work described here, by integration of a standard and convenient software interface, and used in several thermocline survey experiments aimed at gathering oceanographic data relevant to thermoclines. A tool that simulates the longitudinal motion of the OEX through a water slice, whose temperature map is read using a simulated temperature and depth sensor, has been developed. Using this tool and information from at-sea experiments, several control methods for the OEX to track a thermocline were analyzed. In particular, two different algorithms were implemented and tested by simulation. Overall, two control algorithms have been validated, and it will soon be possible to provide the AUV with a thermocline tracking capability.
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Date Issued
2003
PURL
http://purl.flvc.org/fcla/dt/13025
Subject Headings
Thermoclines (Oceanography), Oceanographic submersibles--Computer simulation, Underwater navigation
Format
Document (PDF)
modular guidance, navigation and control system for unmanned surface vehicles
Title
A modular guidance, navigation and control system for unmanned surface vehicles.
Creator
Furfaro, Thomas C., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
The design and integration of an unmanned surface vehicle (USV) control system is described. A survey of related work in both USV control, and unmanned vehicle operating software is presented. The hardware subsystem comprising a modular Guidance, Navigation, and Control (GNC) package is explained. A multi-threaded software architecture is presented, utilizing a decentralized, mutex-protected shared memory inter-process communication subsystem to provide interoperability with additional...
Show moreThe design and integration of an unmanned surface vehicle (USV) control system is described. A survey of related work in both USV control, and unmanned vehicle operating software is presented. The hardware subsystem comprising a modular Guidance, Navigation, and Control (GNC) package is explained. A multi-threaded software architecture is presented, utilizing a decentralized, mutex-protected shared memory inter-process communication subsystem to provide interoperability with additional software modules. A generic GNC approach is presented, with particular elaboration on a virtual rudder abstraction of differential thrust platforms. A MATLAB Simulink simulation is presented as a tool for developing an appropriate controller structure, the result of which was implemented on the target platform. Software validation is presented via a series of sea trials. The USV was tested both in open- and closed-loop control configurations, the results of which are presented here. Lastly recommendations for future development of the GNC system are enumerated.
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Date Issued
2012
PURL
http://purl.flvc.org/FAU/3342052
Subject Headings
Underwater navigation, Adaptive signal processing, Inertial navigation systems, Oceanographic instruments, Development
Format
Document (PDF)
low-cost, high rate motion measurement system for an unmanned surface vehicle with underwater navigation and oceanographic applications
Title
A low-cost, high rate motion measurement system for an unmanned surface vehicle with underwater navigation and oceanographic applications.
Creator
Gelin, Chrystel., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
Standard GPS receivers are unable to provide the rate or precision required when used on a small vessel such as an Unmanned Surface Vehicles (USVs). To overcome this, the thesis presents a low cost high rate motion measurement system for an USV with underwater and oceanographic purposes. The work integrates an Inertial Measurement Unit (IMU), a GPS receiver, a flux-gate compass, a tilt sensor and develops a software package, using real time data fusion methods, for an USV to aid in the...
Show moreStandard GPS receivers are unable to provide the rate or precision required when used on a small vessel such as an Unmanned Surface Vehicles (USVs). To overcome this, the thesis presents a low cost high rate motion measurement system for an USV with underwater and oceanographic purposes. The work integrates an Inertial Measurement Unit (IMU), a GPS receiver, a flux-gate compass, a tilt sensor and develops a software package, using real time data fusion methods, for an USV to aid in the navigation and control as well as controlling an onboard Acoustic Doppler Current Profiler (ADCP).While ADCPs non-intrusively measure water flow, they suffer from the inability to discriminate between motions in the water column and self-motion. Thus, the vessel motion contamination needs to be removed to analyze the data and the system developed in this thesis provides the motion measurements and processing to accomplish this task.
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Date Issued
2010
PURL
http://purl.flvc.org/FAU/2709690
Subject Headings
Oceanographic instruments, Evaluation, Underwater navigation, Adaptive signal processing, Inertial navigation systems, Wave motion, Theory of
Format
Document (PDF)
Design and implementation of an altitude flight controller for the FAU Ocean Voyager II
Title
Design and implementation of an altitude flight controller for the FAU Ocean Voyager II.
Creator
White, Kevin Andrew., Florida Atlantic University, Smith, Samuel M., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
Autonomous underwater vehicle (AUV) missions are generally of a multi-tasked nature, i.e., there are usually several criteria which need to be met concurrently during the course of a mission. An example is the bottom altitude tracking mission proposed by the University of South Florida. They have developed a bottom classification and albedance package (BCAP) which will be used to record data to ground-truth oceanographic satellites. Two criteria needed for this mission are vehicle safety and...
Show moreAutonomous underwater vehicle (AUV) missions are generally of a multi-tasked nature, i.e., there are usually several criteria which need to be met concurrently during the course of a mission. An example is the bottom altitude tracking mission proposed by the University of South Florida. They have developed a bottom classification and albedance package (BCAP) which will be used to record data to ground-truth oceanographic satellites. Two criteria needed for this mission are vehicle safety and motion stability of the recording sensors. This thesis will respectively compare the results of three bottom altitude tracking controllers: a linear modification of an existing depth controller, a TSK fuzzy logic controller, and a behavior based decision controller. Aspects analyzed for meeting the criteria were the ability of the auv to avoid collisions with bottom, the ability of the auv to maintain a desired altitude above the sea floor, and the ability of the auv to keep the amount of blur in a picture taken by a downward looking camera under one pixel. From simulation and real world testing, final results indicate the behavioral based decision controller was proven to be the most robust and the only controller tested to be able to handle multi-criteria.
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Date Issued
1996
PURL
http://purl.flvc.org/fcla/dt/15236
Subject Headings
Remote submersibles, Underwater navigation, Underwater exploration, Altitudes--Measurement, Oceanographic submersibles--Design
Format
Document (PDF)
Performance and limitations of acoustic positioning using a tetrahedral ultra-short baseline array and an acoustic modem source transmitting frequency-hopped sequences
Title
Performance and limitations of acoustic positioning using a tetrahedral ultra-short baseline array and an acoustic modem source transmitting frequency-hopped sequences.
Creator
Mohamed, Asif I., Florida Atlantic University, Beaujean, Pierre-Philippe, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
The operation of unmanned underwater vehicles requires communications with other nearby vehicles as well as accurate positioning to prevent duplication of work, collisions and other mishaps. This thesis details the integration of an ultra-short baseline positioning system with four transducers arranged as a tetrahedron for use with the FAU Dual Purpose Acoustic Modem. The source position is estimated by processing coherently a series of frequency-hopped pulses to obtain a set of bearings,...
Show moreThe operation of unmanned underwater vehicles requires communications with other nearby vehicles as well as accurate positioning to prevent duplication of work, collisions and other mishaps. This thesis details the integration of an ultra-short baseline positioning system with four transducers arranged as a tetrahedron for use with the FAU Dual Purpose Acoustic Modem. The source position is estimated by processing coherently a series of frequency-hopped pulses to obtain a set of bearings, optimally combined through maximum likelihood estimation of the azimuth and elevation. A simulation has been implemented and experiments have been performed in a calibration tank. Model and experiments confirm that the accuracy of this system improves with the number of pulses and the signal-to-noise ratio. A mean positional error of 5.51% can be obtained with an SNR of 20 dB and a single processed pulse, the error decreases to 2.84% using six processed pulses.
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Date Issued
2006
PURL
http://purl.flvc.org/fcla/dt/13412
Subject Headings
Underwater navigation, Remote submersibles, Computer integrated manufacturing systems, Acoustical engineering, Underwater acoustics--Instruments
Format
Document (PDF)
robust AUV docking guidance and navigation approach to handling unknown current disturbances
Title
A robust AUV docking guidance and navigation approach to handling unknown current disturbances.
Creator
Teo, Hoe Eng., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
The main contribution in this thesis is the design of a robust AUV docking guidance and navigation approach that can guide and home an AUV towards an acoustic source located on an oriented bottom-mounted underwater docking station, under presence of unknown current disturbances and in the absence of any form of onboard velocity sensor. A Complementary Filter and various forms of Kalman Filters were separately formulated to estimate the current and vehicle positions with strategic vehicle...
Show moreThe main contribution in this thesis is the design of a robust AUV docking guidance and navigation approach that can guide and home an AUV towards an acoustic source located on an oriented bottom-mounted underwater docking station, under presence of unknown current disturbances and in the absence of any form of onboard velocity sensor. A Complementary Filter and various forms of Kalman Filters were separately formulated to estimate the current and vehicle positions with strategic vehicle manoeuvres. A current compensator uses the estimated current to maintain the desired vehicle course while under current disturbance. Tagaki-Sugeno-Kang Fuzzy Inference System was designed to realize fuzzy docking guidance manoeuvres. Finally, Monte Carlo runs were performed on a designed AUV docking simulator to evaluate the docking robustness against various docking conditions. Simulation results demonstrated robustness in the designed docking guidance and navigation approach.
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Date Issued
2010
PURL
http://purl.flvc.org/FAU/2683137
Subject Headings
Oceanographic submersibles, Computer simulation, Underwater navigation, Fuzzy systems, Automatic control, Mathematical models
Format
Document (PDF)
Static error modeling of sensors applicable to ocean systems
Title
Static error modeling of sensors applicable to ocean systems.
Creator
Ah-Chong, Jeremy Fred., Florida Atlantic University, An, Edgar
Abstract/Description
This thesis presents a method for modeling navigation sensors used on ocean systems and particularly on Autonomous Underwater Vehicles (AUV). An extended Kalman filter was previously designed for the implementation of the Inertial Navigation System (INS) making use of Inertial Measurement Unit (IMU), a magnetic compass, a GPS/DGPS system and a Doppler Velocity Log (DVL). Emphasis is put on characterizing the static sensor error model. A "best-fit ARMA model" based on the Aikake Information...
Show moreThis thesis presents a method for modeling navigation sensors used on ocean systems and particularly on Autonomous Underwater Vehicles (AUV). An extended Kalman filter was previously designed for the implementation of the Inertial Navigation System (INS) making use of Inertial Measurement Unit (IMU), a magnetic compass, a GPS/DGPS system and a Doppler Velocity Log (DVL). Emphasis is put on characterizing the static sensor error model. A "best-fit ARMA model" based on the Aikake Information Criterion (AIC), Whiteness test and graphical analyses were used for the model identification. Model orders and parameters were successfully estimated for compass heading, GPS position and IMU static measurements. Static DVL measurements could not be collected and require another approach. The variability of the models between different measurement data sets suggests online error model estimation.
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Date Issued
2003
PURL
http://purl.flvc.org/fcla/dt/12977
Subject Headings
Underwater navigation, Kalman filtering, Error-correcting codes (Information theory), Detectors
Format
Document (PDF)