Download or read book Design and Evaluation of an Integrated Self contained GPS INS Shallow water Navigation AUV Navigation System SANS written by Randy G. Walker and published by . This book was released on 1996 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design and Evaluation of an Integrated Self Contained GPS INS Shallow Water AUV Navigation System SANS written by Randy G. Walker and published by . This book was released on 1996-06-01 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main problem addressed by this research is to find an alternative to the use of large and/or expensive equipment required by conventional navigation systems to accurately determine the position of an Autonomous Underwater Vehicle (AUV) during all phases of an underwater search or mapping mission. The approach taken was to advance an existing integrated navigation system prototype which combines Global Positioning System (GPS), Inertial Measurement Unit (IMU), water speed, and heading information using Kalman filtering techniques. The hardware and software architecture of the prototype system were advanced to a level such that it is completely self- contained in a relatively small, lightweight package capable of on-board processing of sensor data and outpouring updated position fixes at a rate of 10 Hz; an improvement from the 5 Hz rate delivered by the prototype. The major changes to the preceding prototype implemented by this research were to install an on-board processor to locally process sensor outputs, and improve upon the analog filter and voltage regulation circuitry. Preliminary test results indicate the newly designed SANS provides a 100% performance improvement over the previous prototype. It now delivers a 10Hz update rate, and increased accuracy due to the improved analog filter and the higher sampling rate provided by the processor.

Download or read book Design and Evaluation of an Integrated GPS INS System for Shallow water AUV Navigation written by Eric R. Bachmann and published by . This book was released on 1995 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: The major problem addressed by this research is the large and/or expensive equipment required by a conventional navigation system to accurately determine the position of an Autonomous Underwater Vehicle (AUV) during all phases of an underwater search or mapping mission. The approach taken was to prototype an integrated navigation system which combines Global Positioning System (OPS) and Inertial Measurement Unit (IMU), waterspeed and heading information using Kalman filtering techniques. Actual implementation was preceded by a computer simulation to test where the unit would fit into a larger hardware and software hierarchy of an AUV. The system was then evaluated in experiments which began with land based cart tests and progressed to open water trials where the unit was placed in a towed body behind a boat and alternately submerged and surfaced to provide periodic OPS updates to the Inertial Navigation System (INS). Test results and qualitative error estimates indicate that submerged navigation accuracy comparable to that of differential OPS may be attainable for periods of 30 seconds or more with low cost components of a small physical size.

Download or read book Design and Evaluation of an Integrated GPS INS System for Shallow water AUV Navigation written by Eric R. Bachmann and published by . This book was released on 1995 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The major problem addressed by this research is the large and/or expensive equipment required by a conventional navigation system to accurately determine the position of an Autonomous Underwater Vehicle (AUV) during all phases of an underwater search or mapping mission. The approach taken was to prototype an integrated navigation system which combines Global Positioning System (OPS) and Inertial Measurement Unit (IMU), waterspeed and heading information using Kalman filtering techniques. Actual implementation was preceded by a computer simulation to test where the unit would fit into a larger hardware and software hierarchy of an AUV. The system was then evaluated in experiments which began with land based cart tests and progressed to open water trials where the unit was placed in a towed body behind a boat and alternately submerged and surfaced to provide periodic OPS updates to the Inertial Navigation System (INS). Test results and qualitative error estimates indicate that submerged navigation accuracy comparable to that of differential OPS may be attainable for periods of 30 seconds or more with low cost components of a small physical size.

Download or read book Evaluation of Hardware and Software for a Small Autonomous Underwater Vehicle Navigation System SANS written by Nancy Ann Norton and published by . This book was released on 1994 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this thesis is to evaluate the hardware and software for a Small Autonomous Underwater Vehicle (AUV) Navigation System (SANS), a self-contained, externally mountable navigation system. The SANS is designed to determine the location of an underwater object using a combination of Global Positioning System (GPS) while surfaced, sand Inertial Navigation System (INS) while submerged. Various experimental testing of the hardware was performed to determine the ability of the GPS navigation system to function within the mission requirements. A test was done to determine the time required to obtain a GPS fix. A test of the system while the antenna was covered with water, was done to determine if the GPS signal could penetrate a shallow while the antenna was covered with water, was done to determine if the GPS signal could penetrate a shallow layer of water. Finally, a sea test was done to determine the feasibility of reacquiring a GPS fix after the system has been submerged during normal ocean wave wash. A computer simulation was written in Common LISP Object System (CLOS) in order to evaluate the errors introduced by using a accelerometer in the INS to determine the climb angle of the AUV while surfacing. The experimental testing of the GPS system showed that the GPS signal is able to penetrate a shallow layer of water covering the antenna, and that the system is able to meet the accuracy and time requirements of the mission while being splashed by wave wash. The simulation results show that the error introduced by measuring climb angle with an accelerometer is minor and will not significantly degrade the accuracy of the system.

Download or read book 2484 written by and published by . This book was released on 1941 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Technology Survey and Preliminary Design for Small AUV Navigation System written by Robert B. McGhee and published by . This book was released on 1992 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Navigation of an Autonomous Underwater Vehicle (AUV) is a problem that has not been adequately solved. Although the inclusion of the Global Positioning System (GPS) into AUV navigation has been briefly examined before, this possibility is explored further in this report. GPS and Inertial Measurement System (INS) based navigation package offers many advantages for AUV navigation especially for transit and precise object location in shallow water. This report provides background information on GPS and INS as they pertain to small AUV employment. Other required components are also examined as they pertain to small AUV employment. The use of the GPS/INS navigation package for AUV transits and precise object location work is presented. Two preliminary Small AUV Navigation System (SANS) designs with specified components are developed. GPS, INS, IMV, Navigation, AUV missions Computer System Hardware, Real-Time Software.

Download or read book Analysis Experimental Evaluation and Software Upgrade for Attitude Estimation by the Shallow Water AUV Navigation System SANS written by Ricky L. Roberts and published by . This book was released on 1997-03-01 with total page 209 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main problem addressed by this research is the lack of a small, low-cost integrated navigation system to accurately determine the position of an Autonomous Underwater Vehicle (AUV) during all phases of an underwater search or mapping mission. The approach taken utilized an evolving prototype, called the Shallow-Water AUV Navigation System (SANS), combining Global Positioning System (GPS), Inertial Measurement Unit (IMU), water speed, and magnetic heading information using Kalman, low-pass, and complimentary filtering techniques. In previous work, addition of a math coprocessor improved system update rate from 7 to 18 Hz, but revealed input/output coordination weaknesses in the software. The central focus of this thesis is on testing and programming improvements which resulted in reliable integrated operations and an increased processing speed of 40 Hz. This now allows the filter to perform in real time. A standardized tilt table evaluation and calibration procedure for the navigation filter also was developed. The system was evaluated in dynamic tilt table experiments. Test results and qualitative error estimates using differential GPS suggest that submerged navigation with SANS for a period of several minutes will result in position estimation errors typically on the order of 10 meters rms, even in the presence of substantial ocean currents.

Download or read book Testing and Evaluation of the Small Autonomous Underwater Vehicle Navigation System SANS written by Suat Arslan and published by . This book was released on 2000-03-01 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: At the Naval Postgraduate School (NPS), a small AUV navigation system (SANS) was developed for research in support of shallow-water mine countermeasures and coastal environmental monitoring The objective of this thesis is to test and evaluate the SANS performance after tuning the filter gains through a series of testing procedures. The new version of SANS (SANS III) used new hardware components which were smaller, cheaper, and more reliable. A PC/l O4 computer provided more computing power and, increased the reliability and compatibility of the system. Implementing an asynchronous Kalman filter in the position and velocity estimation part of the navigation subsystem improved the navigation accuracy significantly. To determine and evaluate the overall system performance, ground vehicle testing was conducted. Test results showed that the SANS III was able to navigate within + 15 feet of Global Positioning track with no Global Positioning update for three minutes.

Download or read book A Software Architecture for a Small Autonomous Underwater Vehicle Navigation System written by Clark D. Stevens and published by . This book was released on 1993 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis documents the development of an interim Small Autonomous Underwater Vehicle (AUV) Navigation System (SANS), a self-contained, externally mountable navigation package. The purpose of SANS is to determine the position of a submerged object of interest located by an AUV. The volume of SANS must not exceed 120 cubic inches and total system accuracy of 10.0 meters rms or better is required. An Inertial Navigation System (INS) is implemented to compute the ascent path during transit from an object of interest to the surface. INS hardware components include miniature spin gyroscopes, a compass and a depth transducer interfaced through an analog to digital converter. Global Positioning System (GPS) is used to determine the AUV's location after reaching the surface. The reciprocal of the ascent vector is applied to the AUV's GPS position to accurately determine the location of the target of interest. A primarily object- oriented software architecture is implemented here with extensive software testing to verify the proper operation of key modules. The objective of this thesis is to quantify the adequacy of the selected components in meeting these requirements and to develop a breadboard design demonstrating the basic functions of the interim SANS. This research concludes that the components selected for the interim SANS meet the accuracy requirements provided the AUV maintains a climb angle which is equal to or steeper than 12 degrees from a typical mission depth of 20 meters.

Download or read book An Integrated INS GPS Navigation System for Small AUVs Using an Asynchronous Kalman Filer written by Glenn C. Hernandez and published by . This book was released on 1998 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt: A Small AUV Navigation System (SANS) is being developed at the Naval Postgraduate School. The SANS is an integrated INS/GPS navigation system composed of low-cost, small-size components. It is designed to demonstrate the feasibility of using a low-cost Inertial Measurement Unit (IMU) to navigate between intermittent GPS fixes. This thesis presents recent improvements to the SANS hardware and software. The 486-based ESP computer used in the previous version of SANS is now replaced by an AMD 586DX133 based PC/104 computer to provide more computing power, reliability and compatibility with PC/104 industrial standards. The previous SANS navigation filter consisting of a complementary constant gain filter is now aided by an asynchronous Kalman filter. This navigation filter has six states for orientation estimation (constant gain) and eight states for position estimation (Kalman filtered). Low- frequency DGPS noise is explicitly modeled based on an experimentally obtained autocorrelation function. Ocean currents are also modeled as a low-frequency random process. The asynchronous nature of GPS measurements resulting from AUV submergence or wave splash on the DGPS antennas is also taken into account by adopting an asynchronous Kalman filter as the basis for the SANS software. Matlab simulation studies of the asynchronous filter have been conducted and results documented in this thesis.

Download or read book An Integrated INS GPS Navigation System for Small AUVS Using an Asynchronous Kalman Filter written by Glenn C. Hernandez and published by . This book was released on 1998 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: A Small AUV Navigation System (SANS) is being developed at the Naval Postgraduate School. The SANS is an integrated INS/GPS navigation system composed of low-cost, small-size components. It is designed to demonstrate the feasibility of using a low-cost Inertial Measurement Unit (IMU) to navigate between intermittent GPS fixes. This thesis presents recent improvements to the SANS hardware and software. The 486-based ESP computer used in the previous version of SANS is now replaced by an AMD 586DX133 based PC/104 computer to provide more computing power, reliability and compatibility with PC/104 industrial standards. The previous SANS navigation filter consisting of a complementary constant gain filter is now aided by an asynchronous Kalman filter. This navigation filter has six states for orientation estimation (constant gain) and eight states for position estimation (Kalman filtered). Low-frequency DGPS noise is explicitly modeled based on an experimentally obtained a autocorrelation function. Ocean currents are also modeled as a low-frequency random process. The asynchronous nature of GPS measurements resulting from AUV submergence or wave splash on the DGPS antennas is also taken into account by adopting an asynchronous Kalman filter as the basis for the SANS software. Matlab simulation studies of the asynchronous filter have been conducted and results documented in this thesis.

Download or read book Incorporation of GPS INS Into Small Autonomous Underwater Vehicle Navigation written by and published by . This book was released on 1992 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Navigation of an Autonomous Underwater Vehicle (AUV) is a problem that has not been adequately solved. Although the inclusion of the Global Positioning System (GPS) into AUV navigation has been briefly examined before, this possibility is explored further in this thesis. GPS and Inertial Measurement System (INS) based navigation package offers many advantages for AUV navigation especially for transits and precise object location in shallow water. This thesis provides background information on GPS and INS as they pertain to small AUV employment. Other required components are also examined as they pertain to small AUV employment. The use of the GPS/INS navigation package for AUV transits and precise object location work is presented. Two designs with specified components are developed. A GPS receiver was tested for AUV employment suitability. These test results are presented and analyzed. Autonomous underwater vehicles, Global positioning system, Inertial measurement system.

Download or read book Simulation Based Validation of Navigation Filter Software for a Shallow Water AUV Navigation System SANS written by Ruediger Steven and published by . This book was released on 1996-03-01 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: Navigation filter software is currently being developed for an inertial navigation system without rotating gyros. This system shall replace the navigation system that is currently used in the Phoenix Autonomous Underwater Vehicle of the Naval Postgraduate School. The filter combines acceleration sensors, angular rate sensors, a water speed sensor, a magnetic compass and a GPS system. The harmonization of the sensors is performed by gain matrices. The filter code must be tested for correctness and evaluated, and optimal values for the gain matrices must be found. Both factors directly influence the accuracy of the computed positions, and thus the quality of AUV navigation. in this thesis, the Kalman filter code is tested by experimentation with a simulation of a submarine. Two versions of the code are available, both written in LISP and C++. Test runs are performed in different simulated sea-states (water current), with and without noise added to the sensors, and with different values for the gain matrices. Based on the experiments, the Kalman filter code seems to be correct and stable. Noise is the most important determinant of the filter performance. The results can be optimized by careful fine tuning of the gain matrices.

Download or read book Hardware Integration of the Small Autonomous Underwater Vehicle Navigation System SANS Using a PC 104 Computer written by Kadir Akyol and published by . This book was released on 1999-03-01 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt: At the Naval Postgraduate School (NPS), a small AUV navigation system (SANS) has been developed for research in support of shallow-water mine countermeasures and coastal environmental monitoring. The objective of this thesis is to develop a new version of SANS, aimed at reducing size and increasing reliability by utilizing state-of-the-art hardware components. The new hardware configuration uses a PC/104 computer system, and a Crossbow DMU-VG Six-Axis Inertial Measurement Unit (IMU). The PC/104 computer provides more computing power and more importantly, increases the reliability and compatibility of the system. Replacing the old IMU with a Crossbow IMU' eliminates the need for an analog-to-digital (A/D) converter, and thus reduces the overall size of the SANS. The new hardware components are integrated into a working system. A software interface is developed for each component. An asynchronous Kalman filter is implemented in the current SANS system as a navigation filter. Bench testing is conducted and indicates that the system works properly. The new components reduce the size of the system by 52% and increase the sampling rate to more than 80Hz.

Download or read book A Software Architecture for a Small Autonomous Underwater Vehicle Navigation System written by Clark D. Stevens and published by . This book was released on 1993 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis documents the development of an interim Small Autonomous Underwater Vehicle (AUV) Navigation System (SANS), a self-contained, externally mountable navigation package. The purpose of SANS is to determine the position of a submerged object of interest located by an AUV. The volume of SANS must not exceed 120 cubic inches and total system accuracy of 10.0 meters rms or better is required. An Inertial Navigation System (INS) is implemented to compute the ascent path during transit from an object of interest to the surface. INS hardware components include miniature spin gyroscopes, a compass and a depth transducer interfaced through an analog to digital converter. Global Positioning System (GPS) is used to determine the AUV's location after reaching the surface. The reciprocal of the ascent vector is applied to the AUV's GPS position to accurately determine the location of the target of interest. A primarily object- oriented software architecture is implemented here with extensive software testing to verify the proper operation of key modules. The objective of this thesis is to quantify the adequacy of the selected components in meeting these requirements and to develop a breadboard design demonstrating the basic functions of the interim SANS. This research concludes that the components selected for the interim SANS meet the accuracy requirements provided the AUV maintains a climb angle which is equal to or steeper than 12 degrees from a typical mission depth of 20 meters.

Download or read book Development and Testing of Navigation Algorithms for Autonomous Underwater Vehicles written by Francesco Fanelli and published by Springer. This book was released on 2019-04-16 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on pose estimation algorithms for Autonomous Underwater Vehicles (AUVs). After introducing readers to the state of the art, it describes a joint endeavor involving attitude and position estimation, and details the development of a nonlinear attitude observer that employs inertial and magnetic field data and is suitable for underwater use. In turn, it shows how the estimated attitude constitutes an essential type of input for UKF-based position estimators that combine position, depth, and velocity measurements. The book discusses the possibility of including real-time estimates of sea currents in the developed estimators, and highlights simulations that combine real-world navigation data and experimental test campaigns to evaluate the performance of the resulting solutions. In addition to proposing novel algorithms for estimating the attitudes and positions of AUVs using low-cost sensors and taking into account magnetic disturbances and ocean currents, the book provides readers with extensive information and a source of inspiration for the further development and testing of navigation algorithms for AUVs.