Navigation, Guidance, Control and Dynamics Commons^™

Vessel Traffic Service As A Maritime Security Tool : Vessel Traffic Management Information Systems (Vtmis) In Ghana, Joseph Akwasi Kuma

World Maritime University Dissertations

The dissertation is an assessment of the role of the VTMIS in enhancing efforts to bring down maritime security in the threats in the Gulf of Guinea in West Africa focusing on Ghana. According to the International Maritime Organisation (IMO), Vessel Traffic Service (VTS) is implemented by a Competent Authority to improve the safety and efficiency of vessel traffic and to protect the environment. Technological development today has led to significant improvements in vessel traffic service. Vessel Traffic Management Information Service is the integration of Management information systems to improve the quality of vessel traffic services. Vessel traffic services essentially …

A Study On The Effects Of E-Navigation On Reducing Vessel Accidents, Sun-Bae Hong

World Maritime University Dissertations

The dissertation aims to evaluate how and to what extent e-navigation contributes to reducing accidents for SOLAS ships as well as non-SOLAS ships, hoping that the results are referred to IMO Member States when they are implementing enavigation along with the maritime sectors such as shipping companies, crews on board ships and manufactures developing e-navigation related systems. The study focuses on the potential effects of e-navigation based on tool kits of the IMO e-navigation for SOLAS ships and services of SMART-navigation, which is the Korean approach to implementing the e-navigation concept for both SOLAS ships and non-SOLAS ships. The processes …

Terrain Referenced Navigation Using Sift Features In Lidar Range-Based Data, Matthew T. Leines

Theses and Dissertations

The use of GNSS in aiding navigation has become widespread in aircraft. The long term accuracy of INS are enhanced by frequent updates of the highly precise position estimations GNSS provide. Unfortunately, operational environments exist where constant signal or the requisite number of satellites are unavailable, significantly degraded, or intentionally denied. This thesis describes a novel algorithm that uses scanning LiDAR range data, computer vision features, and a reference database to generate aircraft position estimations to update drifting INS estimates. The algorithm uses a single calibrated scanning LiDAR to sample the range and angle to the ground as an aircraft …

Optimal Collision Avoidance Trajectories For Unmanned/Remotely Piloted Aircraft, Nathan E. Smith

Theses and Dissertations

The post-911 environment has punctuated the force-multiplying capabilities that Remotely Piloted Aircraft (RPA) provides combatant commanders at all echelons on the battlefield. Not only have unmanned aircraft systems made near-revolutionary impacts on the battlefield, their utility and proliferation in law enforcement, homeland security, humanitarian operations, and commercial applications have likewise increased at a rapid rate. As such, under the Federal Aviation Administration (FAA) Modernization and Reform Act of 2012, the United States Congress tasked the FAA to provide for the safe integration of civil unmanned aircraft systems into the national airspace system (NAS) as soon as practicable, but not later …

Cloud-Induced Uncertainty For Visual Navigation, Alyssa N. Gutierrez

Theses and Dissertations

This research addresses the numerical distortion of features due to the presence of clouds in an image. The research aims to quantify the probability of a mismatch between two features in a single image, which will describe the likelihood that a visual navigation system incorrectly tracks a feature throughout an image sequence, leading to position miscalculations. First, an algorithm is developed for calculating transparency of clouds in images at the pixel level. The algorithm determines transparency based on the distance between each pixel color and the average pixel color of the clouds. The algorithm is used to create a dataset …

Identification Of Hydrodynamic Forces Developed By Flapping Fins In A Watercraft Propulsion Flow Field, Erdem Aktosun

LSU New Orleans Theses and Dissertations

In this work, the data analysis of oscillating flapping fins is conducted for mathematical model. Data points of heave and surge force obtained by the CFD (Computational Fluid Dynamics) for different geometrical kinds of flapping fins. The fin undergoes a combination of vertical and angular oscillatory motion, while travelling at constant forward speed. The surge thrust and heave lift are generated by the combined motion of the flapping fins, especially due to the carrier vehicle’s heave and pitch motion will be investigated to acquire system identification with CFD data available while the fin pitching motion is selected as a function …

Vision-Aided Navigation For Gps-Denied Environments Using Landmark Feature Identification, Tennyson Samuel John

Doctoral Dissertations and Master's Theses

In recent years, unmanned autonomous vehicles have been used in diverse applications because of their multifaceted capabilities. In most cases, the navigation systems for these vehicles are dependent on Global Positioning System (GPS) technology. Many applications of interest, however, entail operations in environments in which GPS is intermittent or completely denied. These applications include operations in complex urban or indoor environments as well as missions in adversarial environments where GPS might be denied using jamming technology.

This thesis investigate the development of vision-aided navigation algorithms that utilize processed images from a monocular camera as an alternative to GPS. The vision-aided …

Achieving Global Range In Future Subsonic And Supersonic Airplanes, Nihad E. Daidzic Ph.D., Sc.D.

International Journal of Aviation, Aeronautics, and Aerospace

No commercial airplane in service today is able to fly half great-circle distances over the globe and achieve the non-stop or the global range to any antipodal location on Earth. A subsonic jetliner has the optimum cruising speed at Mach numbers approaching the drag divergence Mach number while still preserving relatively high aerodynamic efficiency. Various fuel-flow laws were used to investigate the cruise performance of subsonic and supersonic aircraft. The effect of wind and aircraft weight and how it affects the optimal cruising airspeed was investigated. Of all different operational cruising techniques, the cruise-climb at high Mach numbers is the …

Dynamic Simulation Of Aerial Trolley Alternative To The Mighty Eagle, Jerry Sweafford

Von Braun Symposium Student Posters

No abstract provided.

Improving Airplane Touchdown Control By Utilizing The Adverse Elevator Effect, Nihad E. Daidzic Ph.D., Sc.D.

International Journal of Aviation, Aeronautics, and Aerospace

The main objective of this original research article is to understand the short-term dynamic behavior of the transport-category airplane during landing flare elevator control application. Increasing the pitch angle to arrest the sink rate, the elevator will have to produce negative lift to rotate the airplane’s nose upward. This has an immediate adverse effect of initially accelerating airplane downward. A mathematical model of landing flare based on the flat-Earth longitudinal dynamics of rigid airplane was developed which is realistic only on very short time-scales as pitch stiffness and damping were neglected. Pilot control scenarios using impulse and step elevator pull-up …

Control Of A Spacecraft Using Mixed Momentum Exchange Devices, Blake J. Currie

Master's Theses

Hardware configurations, a control law, and a steering law are developed for a mixed hardware spacecraft that uses both control moment gyros and reaction wheels. Replacing one or more gyros in a spacecraft with a reaction wheel has potential for cost savings while still achieving much greater performance than using reaction wheels alone. Several simulated tests are run to compare the performance to a traditional all reaction wheel or all control moment gyro spacecraft, including analysis of failure modes and singular configurations. The mixed system performed similarly to all gyro systems, responding within 6% of the gyro system’s time for …

Trajectory Optimization For A Misson To The Trojan Asteroids, Shivaji Senapati Gadsing

Masters Theses

The problem of finding a minimum-fuel trajectory for a mission to the Jovian Trojan asteroids is considered. The problem is formulated as a modified traveling salesman problem. Two different types of algorithms such as an exhaustive search algorithm and a serial rendezvous search algorithm are developed. The General Mission Analysis Tool (GMAT) is employed for finding optimum trajectories with minimal fuel consumption. The selection of a minimum-fuel mission trajectory, and the associated target asteroids, will be a key factor in determining feasibility and scientific value of a Trojan tour and rendezvous mission.

The transfer trajectory followed by a spacecraft between …

Feedback Speed Control Of A Small Two-Stroke Internal Combustion Engine That Propels An Unmanned Aerial Vehicle, Paul D. Fjare

UNLV Theses, Dissertations, Professional Papers, and Capstones

Unmanned aerial vehicles (UAV) require intelligent control of their power source. Small UAV are typically powered by electric motors or small two-stroke internal combustion (IC) engines. Small IC engines allow for longer flight times but are more difficult to control and cause significant ground noise. A hybrid operation that uses the engine at high altitudes and the electric motors at low altitudes is desired. This would allow for extended flight with acceptable ground noise levels. Since the engine can not be restarted in the air it must be able to remain at idle for an extended time without stalling. A …

The Differential Vector Phase-Locked Loop For Global Navigation Satellite System Signal Tracking, James J. Brewer

Theses and Dissertations

A novel differential vector phase-locked loop (DVPLL) is derived that takes GNSS code-phase and carrier-phase measurements from a base station and uses them to maintain an integer ambiguity resolved quality solution directly in the vector tracking loop of a rover receiver. The only state variables estimated and used to create the replica code and carrier signals from the base station measurements are three position and two clock states for a static test. Closing the individual loops solely through the navigation filter makes this a pure vector method. For short baselines, where differential atmospheric errors are small, the DVPLL can be …

Non-Linear Optimization Applied To Angle-Of-Arrival Satellite-Based Geolocation, Stephen D. Hartzell

Theses and Dissertations

Geolocation is a common application for satellite systems. This involves estimating an object's location (herein called the subject) based on noisy satellite data. Many geolocation methods exist; however, none are tailored specifically for the unique problems faced by satellite systems. Some satellites are so far from the subject being localized that by the time the satellite receives a signal from the subject it might have moved appreciably. Furthermore, some satellites or terrestrial sensors may be much closer to the subject than others. Therefore, sensors may need to be weighted based upon their distance to the subject being localized. In addition, …

Localization And System Identification Of A Quadcopter Uav, Kenneth Befus

Masters Theses

The research conducted explores the comparison of several trilateration algorithms as they apply to the localization of a quadcopter micro air vehicle (MAV). A localization system is developed employing a network of combined ultrasonic/radio frequency sensors used to wirelessly provide range (distance) measurements defining the location of the quadcopter in 3-dimensional space. A Monte Carlo simulation is conducted using the extrinsic parameters of the localization system to evaluate the adequacy of each trilateration method as it applies to this specific quadcopter application. The optimal position calculation method is determined.

Furthermore, flight testing is performed in which real range measurement data …

Reduced-Order Reference Models For Adaptive Control Of Space Structures, Alexander I. Scherling

Master's Theses

In addition to serving as a brief overview of aspects relevant to reduced-order modeling (in particular balanced-state and modal techniques) as applied to structural finite element models, this work produced tools for visualizing the relationship between the modes of a model and the states of its balanced representation.

Specifically, error contour and mean error plots were developed that provide a designer with frequency response information absent from a typical analysis of a balanced model via its Hankel singular values. The plots were then used to analyze the controllability and observability aspects of finite element models of an illustrative system from …

Modification Of The Cal Poly Spacecraft Simulator System For Robust Control Law Verification, Tomoyuki Kato

Master's Theses

The Cal Poly Spacecraft Dynamics Simulator, also known as the Pyramidal Reaction Wheel Platform (PRWP), is an air-bearing four reaction wheel spacecraft simulator designed to simulate the low-gravity, frictionless condition of the space environment and to test and validate spacecraft attitude control hardware and control laws through real-time motion tests. The PRWP system was modified to the new Mk.III configuration, which adopted the MATLAB xPC kernel for better real-time hardware control. Also the Litton LN-200 IMU was integrated onto the PRWP and replaced the previous attitude sensor. Through the comparison of various control laws through motion tests the Mk.III configuration …

Optimum Path Planning For An Impaired Aircraft, Suzannah Bailey

Renée Crown University Honors Thesis Projects - All

Proportionally speaking, it is safer to travel by plane than any other form of transportation. However, in some parts of the world such as Africa, the lack of updated aircraft, instability within the region, and inexperience of flight crews contribute to a higher rate of aircraft incidents and accidents. This capstone combines elements from aerospace engineering, as well as international relations to create a program to mitigate these risks.

This new algorithm, the Bailey Algorithm, is very different from the commonly used Dijkstra Algorithm. Unlike Dijkstra, the Bailey Algorithm not only incorporates the distance traveled between cities, but it also …

Autonomous Close Formation Flight Of Small Uavs Using Vision-Based Localization, Michael B. Darling

Master's Theses

As Unmanned Aerial Vehicles (UAVs) are integrated into the national airspace to comply with the 2012 Federal Aviation Administration Reauthorization Act, new civilian uses for robotic aircraft will come about in addition to the more obvious military applications. One particular area of interest for UAV development is the autonomous cooperative control of multiple UAVs. In this thesis, a decentralized leader-follower control strategy is designed, implemented, and tested from the follower’s perspective using vision-based localization.

The tasks of localization and control were carried out with separate processing hardware dedicated to each task. First, software was written to estimate the relative state …

Applied Mass Properties Identification Method To The Cal Poly's Spacecraft Simulator, Long H. Dam

Master's Theses

The Cal Poly Spacecraft Simulator is currently being developed for future testing and verifying theoretical control applications. This paper details the effort to balance the platform and remove undesired external torque from the system using System Identification technique developed by Patrick Healy. Since the relationship between the input and output of the system is linear, the least square method is proposed to identify the mass properties and location of center of mass of the system. The tests use four sine wave generators that are out of phase with different amplitudes as the inputs to excite various structural modes of the …

System Identification Of An Autonomous Surface Vehicle, Christopher John Cook

Mechanical & Aerospace Engineering Theses & Dissertations

The modeling and system identification of a small pontoon based marine craft, without rudder control, in a controlled environment. Old Dominion University's autonomous surface vehicle was modeled using the Observer/Kalman System Identification method. The experimental position data was collected using a laser positioning system along with Arduino based sensors on board the boat to collect the motor speeds of the dual outboard motors. The data was then compiled using the System/ Observer/Controller Identification Toolbox to derive a dynamic model that is capable of providing path estimation and prediction information to the autonomous robotic system.

Optimal Uav Path Planning For Tracking A Moving Ground Vehicle With A Gimbaled Camera, Riley A. Livermore

Theses and Dissertations

This research develops a path planning algorithm that autonomously controls a UAV to provide convoy overwatch. The optimization algorithm determines the best path to y through developing a cost function that minimizes the control effort of the UAV and the deviation from a desired slant range. A heuristic-based algorithm was developed and implemented on the autopilot to approximate the optimal solution. In flight test, the UAV successfully tracked a moving ground vehicle by continually placing the UAV's loiter point directly above the ground vehicle's current location. This method was called the \follow-me mode and provided the baseline for real-world UAV …

Image-Aided Navigation Using Cooperative Binocular Stereopsis, Justin T. Soeder

Theses and Dissertations

This thesis proposes a novel method for cooperatively estimating the positions of two vehicles in a global reference frame based on synchronized image and inertial information. The proposed technique - cooperative binocular stereopsis - leverages the ability of one vehicle to reliably localize itself relative to the other vehicle using image data which enables motion estimation from tracking the three dimensional positions of common features. Unlike popular simultaneous localization and mapping (SLAM) techniques, the method proposed in this work does not require that the positions of features be carried forward in memory. Instead, the optimal vehicle motion over a single …

Gps Multipath Reduction With Correlator Beamforming, Jason M. Barhorst

Theses and Dissertations

This research effort investigates the feasibility of beamforming using a single Global Positioning System (GPS) front end. Traditional methods of beamforming use multiple front ends, typically one per antenna element. By enabling a receiver to sample a switched antenna array, the hardware cost of implementing a GPS antenna array can be significantly reduced. Similar techniques of reducing the number of receivers have been used by Locata Corporation in the design of their non-GPS positioning systems. However, Locata Corporation's local transmitters provide a signal strength much higher than GPS's signal strength. For this reason, the inclusion of low-noise amplifiers into the …

High-Efficiency Thrust Vector Control Allocation, Jeb S. Orr, Nathan Slegers

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

A generalized approach to the allocation of redundant thrust vector slew commands for multi-actuated launch vehicles is presented, where deflection constraints are expressed as omniaxial or elliptical deflection limits in gimbal axes. More importantly than in the aircraft control allocation problem, linear allocators (pseudoinverses) are preferred for large booster applications to facilitate accurate prediction of the control-structure interaction resulting from thrust vectoring effects. However, strictly linear transformations for the allocation of redundant controls cannot, in general, access all of the attainable moments for which there is a set of control effector positions thatsatisfles the constraints. In this paper, the control …

A Mathematical Framework For Unmanned Aerial Vehicle Obstacle Avoidance, Sorathan Chaturapruek

HMC Senior Theses

The obstacle avoidance navigation problem for Unmanned Aerial Vehicles (UAVs) is a very challenging problem. It lies at the intersection of many fields such as probability, differential geometry, optimal control, and robotics. We build a mathematical framework to solve this problem for quadrotors using both a theoretical approach through a Hamiltonian system and a machine learning approach that learns from human sub-experts' multiple demonstrations in obstacle avoidance. Prior research on the machine learning approach uses an algorithm that does not incorporate geometry. We have developed tools to solve and test the obstacle avoidance problem through mathematics.

Comparative Analysis Of Gps Data, Kiel Von Lindenberg

Undergraduate Journal of Mathematical Modeling: One + Two

The goal of this project is to calculate the distance traveled during a bike ride around the University of South Florida using information gathered by a GPS (Global Positioning System) application on a smartphone. We calculate the route distance in two ways: from latitudes and longitudes using the haversine formula and 2) from velocities and times using the trapezoidal rule. These computed distances were compared to the distance given by the smartphone application.

Filtered-Dynamic-Inversion Control For Fixed-Wing Unmanned Aerial Systems, Jon Mullen

Theses and Dissertations--Mechanical and Aerospace Engineering

Instrumented umanned aerial vehicles represent a new way of measuring turbulence in the atmospheric boundary layer. However, autonomous measurements require control methods with disturbance-rejection and altitude command-following capabilities. Filtered dynamic inversion is a control method with desirable disturbance-rejection and command-following properties, and this controller requires limited model information. We implement filtered dynamic inversion as the pitch controller in an altitude-hold autopilot. We design and numerically simulate the continuous-time and discrete-time filtered-dynamic-inversion controllers with anti-windup on a nonlinear aircraft model. Finally, we present results from a flight experiment comparing the filtered-dynamic-inversion controller to a classical proportional-integral controller. The experimental results show …

Robust And Adaptive Nonlinear Control Of Limit Cycle Oscillations In Uavs Using Synthetic Jet Actuators, Natalie Ramos Pedroza

Doctoral Dissertations and Master's Theses

Limit cycle oscillations (LCO), also known as utter, cause significant challenges in fight control of unmanned aerial vehicles (UAVs), and could potentially lead to structural damage and catastrophic failures. LCO can be described as vibrational motions in the pitching and plunging displacements of an aircraft wing. Even in low Reynolds number (low-Re) fight regimes, LCO can exceed the limiting boundary for safe UAV fight. Further, as practical considerations motivate the design of smaller, lighter weight UAVs, there is a growing need for UAV systems that do not require heavy mechanical actuators (e.g., ailerons). To address this, the use of synthetic …