Navigation, Guidance, Control and Dynamics Commons^™

Verifying And Improving A Flight Reference System's Performance, Loren E. Myers

Theses and Dissertations

The 746th Test Squadron (746 TS) at Holloman AFB, NM operates the Ultra High Accuracy Reference System (UHARS) as part of its mission positioning and navigation test. This research presents a method for verifying the performance of a flight reference system using a Delta-Position velocity derived from radio navigation positioning measurements. The algorithm presented may utilize Global Positioning System (GPS) or the Locata ground based positioning system. In the latter case, Locata provides a velocity truth independent from GPS. The accuracy of Locata and GPS are assessed and UHARS velocity measurements are characterized both in nominal and GPS denied applications.

Improved Ground-Based Monocular Visual Odometry Estimation Using Inertially-Aided Convolutional Neural Networks, Josiah D. Watson

Theses and Dissertations

While Convolutional Neural Networks (CNNs) can estimate frame-to-frame (F2F) motion even with monocular images, additional inputs can improve Visual Odometry (VO) predictions. In this thesis, a FlowNetS-based [1] CNN architecture estimates VO using sequential images from the KITTI Odometry dataset [2]. For each of three output types (full six degrees of freedom (6-DoF), Cartesian translation, and transitional scale), a baseline network with only image pair input is compared with a nearly identical architecture that is also given an additional rotation estimate such as from an Inertial Navigation System (INS). The inertially-aided networks show an order of magnitude improvement over the …

Differential Vector Phase Locked Loop Gps Reception Method, James Brewer, John F. Raquet

AFIT Patents

A method for enhancing GPS location accuracy includes providing a base station receiver having a known surveyed location, and a roving receiver at a location distinct from the base station receiver. The method further includes receiving single-frequency code and carrier-phase measurements from the base station, and translating the single-frequency code and carrier-phase measurements to a Kalman filter-predicted location of the roving receiver. The translated single frequency code and carrier phase measurements are used to generate a local replica of the Kalman filter-predicted location signals for each channel of the roving receiver. The method further includes correlating the local replicas with …

Active Fault-Tolerance Of The Unmanned Aerial Vehicle Automatic Control Systems, Vuong Anh Trung, Nguyen Van Thinh, Nguyen Duc Thanh, Nguyen Quang Vinh, Tran Thuan Hoang

International Journal of Aviation, Aeronautics, and Aerospace

This paper presents an introductory overview of principles of the three-layer hierarchy of active fault-tolerance, providing, determination of the fault type with as many details as enough to get recoverable fault reason and failure toleration by flexible redundancy using; the conception of active fault-tolerant control in abnormal modes is described. Developed models and methods of a systematic approach to fault tolerance in the direction of the effective use of the signal, parametric and structural redundancies and selection of parrying tools. Performed experimental researches of the unmanned aerial vehicle (UAV) automatic control systems (ACS).

Reliable Navigation For Suas In Complex Indoor Environments, Andrew J. Fabian

Theses and Dissertations

Indoor environments are a particular challenge for Unmanned Aerial Vehicles (UAVs). Effective navigation through these GPS-denied environments require alternative localization systems, as well as methods of sensing and avoiding obstacles while remaining on-task. Additionally, the relatively small clearances and human presence characteristic of indoor spaces necessitates a higher level of precision and adaptability than is common in traditional UAV flight planning and execution. This research blends the optimization of individual technologies, such as state estimation and environmental sensing, with system integration and high-level operational planning.

The combination of AprilTag visual markers, multi-camera Visual Odometry, and IMU data can be used …

Fast Decision-Making Under Time And Resource Constraints, Kyle Gabriel Lassak

Graduate Theses, Dissertations, and Problem Reports (ETD)

Practical decision makers are inherently limited by computational and memory resources as well as the time available in which to make decisions. To cope with these limitations, humans actively seek methods which limit their resource demands by exploiting structure within the environment and exploiting a coupling between their sensing and actuation to form heuristics for fast decision-making. To date, such behavior has not been replicated in artificial agents. This research explores how heuristics may be incorporated into the decision-making process to quickly make high-quality decisions through the analysis of a prominent case study: the outfielder problem. In the outfielder problem, …

Pulsed Power Control System, Logan Curtis

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Low-Cost Skewed Redundant Imu Configuration For State-Space Recovery In A Saturated Environment, Levi S. Hubbard

Graduate Theses, Dissertations, and Problem Reports (ETD)

Low-cost sensors for state space determination can be used successfully for ground vehicles, robots, unmanned aerial vehicles, and Internet-of-Things applications. When a high fidelity Inertial Measurement Unit (IMU) cannot be obtained for state space determination, low-cost sensors can be used to satisfactory standards, despite their limitations in capabilities, by using various implementation techniques. The research group was experimentally investigating state space information of an unstable flying vehicle for motion simulation validation. The high fidelity motion capture system would intermittently lose track of the flight vehicle which lost critical flight data.

The goal was to determine the potential of low-cost off-the-shelf …

Adaptive Filtration Of The Uav Movement Parameters Based On The Aoa-Measurement Sensor Networks, Igor Tovkach, Serhii Zhuk

International Journal of Aviation, Aeronautics, and Aerospace

Currently, the urgent task is to assess the small-sized maneuvering UAVs movement parameters. The location of an unknown UAV as a radio source can be determined using AoA measurements of the wireless sensor network. To describe the movement of a maneuvering UAV, a model is used in the form of a dynamic system with switching in discrete time. The values of switching variable determine type of UAV movement. To synthesize trajectory filtering algorithms, the Markov property of the extended process is used, which includes a vector of UAV movement parameters and a switching variable. The optimal trajectory filtering algorithm describes …

Dynamic Delegated Corridors And 4d Required Navigation Performance For Urban Air Mobility (Uam) Airspace Integration, Trong Van Nguyen

Journal of Aviation/Aerospace Education & Research

Increased traffic congestion on urban road networks has impacted the travel time for commuters in highly populated urban centers. Urban Air Mobility (UAM) is recognized as a system that transports the passenger and air cargo from any location to any destination within a metropolitan area. UAM may offer a solution to the problematic issue of automobile urban surface transportation congestion. However, the predicted significant growth in the demand for integration of UAM operations into the existing airspace system in the next 20 years and beyond may exceed the capacity of current air traffic control (ATC) system resources, particularly the ATC …

Assessment Of Egnos Performance For Civil Aviation Flight Phase In The Edge Coverage Area, Bilal Beldjilali, Salem Kahlouche, Lahouaria Tabti

International Journal of Aviation, Aeronautics, and Aerospace

The performances of the navigation systems used for different flight phases especially in the landing of an aircraft must be very high. The International Civil Aviation Organization defines the standards which must meet by any navigation systems to be certified, so it can be used by civil aircraft. To achieve the level of security defined by the International Civil Aviation Organization, new augmentation systems based satellites are developed. In Europe, the EGNOS system was developed to improve both GPS and Galileo performance. In this paper the performance of the EGNOS system for civil aviation flight phase was investigated. Four parameters …

Autonomous Autorotation Of A Tilt-Rotor Aircraft Using Model Predictive Control, Elias Wilson

Doctoral Dissertations and Master's Theses

Tilt rotor vehicles are governed by FAA laws also used for conventional helicopters, which require autorotational maneuvering and landing given a total power failure. With low inertia rotors and high disk loading of tilt rotor vehicles, this already difficult task becomes significantly more challenging. In this work, a model predictive controller is developed to autonomously maneuver and land a tilt rotor given complete power loss. A high fidelity model of a tilt rotor vehicle is created and used to simulate the vehicle dynamics and response to control inputs. A reduced order dynamic model is used within a model predictive control …

Navigational Feasibility Of Flyby / Impact Missions To Interstellar Objects, Declan Moore Mages

Master's Theses

In October 2017, the first interstellar object, designated 1I/2017 U1 and more commonly referred to as Oumuamua, was detected passing through our solar system by the Pan-STARRS telescope, followed recently by the detection of 2I/Borisov in August 2019. These detections came much sooner than thought possible, and have redefined our understanding of the population of interstellar objects. With the construction of the next generation of powerful observatories, future detections are estimated to occur as frequently as two per year, and while there is significant scientific understanding to be gained from observing these objects remotely, a spacecraft sent to intercept one …

A Co-Optimal Coverage Path Planning Method For Aerial Scanning Of Complex Structures, Zhexiong Shang, Justin Bradley, Zhigang Shen

Department of Construction Engineering and Management: Faculty Publications

The utilization of unmanned aerial vehicles (UAVs) in survey and inspection of civil infrastructure has been growing rapidly. However, computationally efficient solvers that find optimal flight paths while ensuring high-quality data acquisition of the complete 3D structure remains a difficult problem. Existing solvers typically prioritize efficient flight paths, or coverage, or reducing computational complexity of the algorithm – but these objectives are not co-optimized holistically. In this work we introduce a co-optimal coverage path planning (CCPP) method that simultaneously co-optimizes the UAV path, the quality of the captured images, and reducing computational complexity of the solver all while adhering to …

Risk Mitigation For Low Latitude Ground-Based Augmentation System (Gbas) Precision Approach Operations, Richard Walter Cole

Doctoral Dissertations and Master's Theses

The ground-based augmentation system (GBAS) is a safety-critical system consisting of the hardware and software that augments the Global Positioning System (GPS) to provide precision approach and landing capability and is one of the navigational cornerstones of the International Civil Aviation Organization's (ICAO) global transition to space-based technologies. In low latitude regions, where the space-based augmentation system (SBAS) cannot provide adequate precision approach service due to large system errors induced by ionospheric delays, GBAS is the best option to provide the primary navigation function for the modernized global air traffic system. The purpose of the study was to identify patterns …

Ion Software-Defined Radio Metadata Standard Final Report, Sanjeev Gunawardena, Alexander Rugamer, Muhammad Subhan Hameed, Markel Arizabaleta, Thomas Pany, Javier Arribas

Faculty Publications

The ION GNSS SDR Metadata Standard describes the formatting and other essential PNT-related parameters of sampled data streams and files. This allows processors to seamlessly consume such data without the need to input these parameters manually. The technical development phase of the initial version of the standard has now been deemed complete and is currently undergoing the last remaining procedural steps towards adoption as a formal standard by the Institute of Navigation. This paper reports on the activities of the working group since September 2018 and summarizes the final products of the standard. It also reports on examples of early …

Gaussian Conditionally Markov Sequences: Theory With Application, Reza Rezaie

LSU New Orleans Theses and Dissertations

Markov processes have been widely studied and used for modeling problems. A Markov process has two main components (i.e., an evolution law and an initial distribution). Markov processes are not suitable for modeling some problems, for example, the problem of predicting a trajectory with a known destination. Such a problem has three main components: an origin, an evolution law, and a destination. The conditionally Markov (CM) process is a powerful mathematical tool for generalizing the Markov process. One class of CM processes, called $CM_L$, fits the above components of trajectories with a destination. The CM process combines the Markov property …

First Approach To Coupling Of Numerical Lifting-Line Theory And Linear Covariance Analysis For Uav State Uncertainty Propagation, Cory D. Goates, Randall S. Christensen, Robert C. Leishman

Faculty Publications

Numerical lifting-line is a computationally efficient method for calculating aerodynamic forces and moments on aircraft. However, its potential has yet to be tapped for use in guidance, navigation, and control (GN&C). Linear covariance analysis is becoming a popular GN&C design tool and shows promise for pairing with numerical lifting-line. Pairing numerical lifting-line with linear covariance analysis allows for forward propagation of state uncertainty for real-time decision making. We demonstrate this for select state variables in a drone aerial recapture situation. Linear covariance analysis uses finite difference derivatives obtained from numerical lifting-line to calculate force and moment variances. These show agreement …

Spacecraft Trajectory Planning For Optimal Observability Using Angles-Only Navigation, Francisco José Franquiz

Doctoral Dissertations and Master's Theses

This work leverages existing techniques in angles-only navigation to develop optimal range observability maneuvers and trajectory planning methods for spacecraft under constrained relative motion. The resulting contribution is a guidance method for impulsive rendezvous and proximity operations valid for elliptic orbits of arbitrary eccentricity.

The system dynamics describe the relative motion of an arbitrary number of maneuvering (chaser) spacecraft about a single non-cooperative resident-space-object (RSO). The chaser spacecraft motion is constrained in terms of the 1) collision bounds of the RSO, 2) maximum fuel usage, 3) eclipse avoidance, and 4) optical sensor field of view restrictions. When more than one …

Nonlinear Observer For Visual-Inertial Navigation Using Intermittent Landmark Measurements, Miaomiao Wang

Western Research Forum

The development of reliable orientation, position and linear velocity estimation algorithms for the 3D visual-inertial navigation system (VINS) is instrumental in many applications, such as autonomous underwater vehicles (AUVs), and unmanned aerial vehicles (UAVs). It is extremely important when the global position system (GPS) is not available in GPS-denied environments. Recently, observers design for VINS using landmark position measurements from Kinect sensors or stereo cameras has been increasingly investigated in the literature.

The aim of this work is to design a nonlinear observer for VINS under the assumption that landmark position measurements are intermittent. In practice, the landmark measurements are …