Current Search: Department of Ocean and Mechanical Engineering (x) » Mahfuz, Hassan (x) » Underwater navigation (x)
View All Items
- 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.
Show less - 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)
- 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.
Show less - Date Issued
- 2001
- PURL
- http://purl.flvc.org/fcla/dt/12735
- Subject Headings
- Oceanographic submersibles--Computer simulation, Underwater navigation
- Format
- Document (PDF)
- 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.
Show less - 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)
- 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.
Show less - 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)
- 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.
Show less - Date Issued
- 2000
- PURL
- http://purl.flvc.org/fcla/dt/12691
- Subject Headings
- Oceanographic submersibles--Computer simulation, Sonar, Underwater navigation
- Format
- Document (PDF)
- 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.
Show less - 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)
- 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.
Show less - 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)
- 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.
Show less - Date Issued
- 1996
- PURL
- http://purl.flvc.org/fcla/dt/15263
- Subject Headings
- Robots, Underwater navigation
- Format
- Document (PDF)
- 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.
Show less - Date Issued
- 2003
- PURL
- http://purl.flvc.org/fcla/dt/13040
- Subject Headings
- Ocean tomography, Sonar, Underwater navigation
- Format
- Document (PDF)
- 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).
Show less - Date Issued
- 2002
- PURL
- http://purl.flvc.org/fcla/dt/12917
- Subject Headings
- Underwater navigation, Underwater acoustics, Signal processing--Digital techniques
- Format
- Document (PDF)