Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 149 for “"Navigation, Guidance, Control, and Dynamics"”.
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A Solution to the Circular Restricted N Body Problem in Planetary Systems
… By focusing on planetary systems, satellite dynamics can be modeled in a fashion similar to the Circular Restricted Three Body Problem (CR3BP) with the Circular Restricted N Body Problem (CRNBP). It was found that this new formulation of the dynamics can then utilize the tools created from …
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Design and Control Considerations for a Skid-to-Turn Unmanned Aerial Vehicle
… Unmanned Aerial Vehicles (UAVs) are rapidly expanding and taking on new roles in the military. In the area of training and targeting vehicles, control systems are expanding the functionality of UAVs beyond their initially designed purpose. Aeromech Engineering’s NXT UAV is a high speed target …
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On the Stability and Robustness of Discrete Uncertain Systems
<p>Model reference adaptive control (MRAC) is a well-established control design framework for ensuring closed-loop system stability and reference tracking performance in dynamical systems with uncertainties. Nominal, fixed-gain controllers rely on accurate mathematical models to guarantee desired …
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Model Predictive Control for Autonomous Landing in Complex Scenarios
<p>The autonomous flight industry is ever-expanding and continuing to push the boundaries of what is possible within the limitations of technology. Multiple companies are exploring the use of autonomous flight for intra-city travel with air taxi services and package delivery vehicles. Other …
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Evaluation of Probabilistic Methodology for Predicting Satellite Tracking Resources
… satellite tracking networks to provide tracking and data acquisition services to large constellations of satellites. This approach, developed by Hagar is evaluated using Monte Carlo simulations of optimal satellite contact scheduling on a tracking network for a certain class of satellites. The …
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Flying Qualities Built-in-Test for Unmanned Aerial Systems
… axis. A doublet input waveform excites the AV and both α and q are used by EUDKF to estimate the A and B matrices which are short period approximations of the system. ζ, ω, GM, PM, observability, and controllability are calculated to determine flying qualities with the results displayed to the …
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Geomagnetic Aided Dead-Reckoning Navigation
<p>The dependence of modern navigation methods on global positioning systems has led to developing alternative algorithms for localization, capable of providing reliable and robust estimations. Global position system is commonly used in a vast majority of the world’s devices, and it can supply real …
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Implementation of a Low Cost Micro Electro Mechanical Systems Inertial Navigation Solution
… purpose of this study is to develop a low cost navigation solution for General Aviation (GA) aircraft and flight testing aircraft. This low cost solution uses a Global Positioning System (GPS) coupled with an Inertial Navigation Solution (INS) to provide a more accurate, stable navigation …
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Vision-Aided Navigation using Tracked Landmarks
… the algorithm leverages recognizable ‘landmarks’ in the environment, the positions of which are known in advance, to stabilize the state estimate. Measurements of the position of one or more landmarks in the image plane of a monocular camera are then filtered using an extended Kalman …
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Control System Development for Small UAV Gimbal
… mass to increase stabilization performance and imagery quality. However, through the use of new sensor and processor technology high performance stabilization feedback is being made available for control on new small and low mass stabilized platforms that can be placed on small UAVs. This …
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Adaptive Control of VSCMGs for Satellite Attitude Tracking
… space has brought about many new opportunities and challenges for industry, academia, and governments. Smaller and more affordable platforms are now regularly being launched. These platforms have higher uncertainty due to cost, engineering constraints, unmodeled dynamics, coupled effects, and …
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Magneto-Rheological Fluid Device as Artificial Feel Force System on Aircraft Control Stick
… any aircraft occupies large space in the cockpit and has complicated designs. The primary objective of this research is to develop an artificial feel force system that can overcome some drawbacks of the current feel force system. A novel feel system using magneto-rheological (MR) fluid is …
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Dynamics and Control of Higher-order Nonholonomic Systems
<p>A theoretical framework is established for the control of higher-order nonholonomic systems, defined as systems that satisfy higher-order nonintegrable constraints. A model for such systems is developed in terms of differential-algebraic equations defined on a higher-order tangent bundle. A …
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Development of a Remotely-Piloted Vehicle Platform to Support Implementation, Verification, and Validation of Pilot Control Systems
… presents the development of a research test bed and the use of a set of metrics for evaluating handling qualities with pilot in the loop configuration. The main objective of this study is to provide software and hardware tools to support performance evaluation of control systems designed to …
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Nonholonomic Feedback Control Among Moving Obstacles
<p>A feedback controller is developed for navigating a nonholonomic vehicle in an area with multiple stationary and possibly moving obstacles. Among other applications the developed algorithms can be used for automatic parking of a passenger car in a parking lot with complex configuration or a …
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Dynamic Understeer Control Using Active Rear Toe
… to show the ability of Active Rear Toe to control the understeer characteristics of a vehicle. Active rear toe is the ability to control the angle of the rear wheels around the vertical axis, allowing the car’s turning radius to change. By changing this radius, the lateral acceleration can …
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Attitude Determination Using Imaging Lidar
… study is to determine the attitude of an out of control object using a new technology called lidar (Light Ranging and Detection). As the number of spacecraft continues to grow, it is paramount to introduce a new type of autonomous on-orbit satellite inspection and repair involving docking. …
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Maneuvering Control of a Spacecraft with Propellant Sloshing
… propellant motion. Although effective, baffles and bladders add to spacecraft mass and structural complexity. In this research, the sloshing fuel mass is treated as an unactuated degree of freedom within a rigid body. Specifically, the propellant is modeled as a pendulum mass anchored at the …
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Adaptive Commanding of Control Moment Gyroscopes with Backlash
… significant challenges when attempting to control these systems to a high degree of precision. The imperfect meshing of gear or belt teeth deteriorates the performance of position controllers and tracking of small commands, producing unacceptable steady-state offsets, increased rise and …
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An Experimental Investigation of Direct and Indirect Viewing of a Remote Manipulation
… purpose of this study was to evaluate direct and indirect viewing of a remote manipulation. With continued exploration of inner and outer space, the ability to directly manipulate objects is lost due to the nature of operating in harsh environments. Remote viewing and operation of equipment is …
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