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Gps-Denied Localization Of Landing Evtol Aircraft, Aaron C. Brown
Gps-Denied Localization Of Landing Evtol Aircraft, Aaron C. Brown
Theses and Dissertations
This thesis presents a dedicated GPS-denied landing system designed for electric vertical takeoff and landing (eVTOL) aircraft. The system employs active fiducial light pattern localization (AFLPL), which provides highly accurate and reliable navigation during critical landing phases. AFLPL utilizes images of a constellation comprised of modulating infrared lights strategically positioned on the landing site, to determine the aircraft pose through the use of a perspective-n-point (PnP) solver. The AFLPL system underwent thorough development, enhancement, and implementation to address and demonstrate its potential in navigation and its inherent limitations. A proposed method addresses the limitations of AFLPL by using an extended …
Developing A Vision-Based Framework For Measuring And Monitoring Water Resource Systems Using Computer Vision And Deep Learning Techniques, Seyed Mohammad Hassan Erfani
Developing A Vision-Based Framework For Measuring And Monitoring Water Resource Systems Using Computer Vision And Deep Learning Techniques, Seyed Mohammad Hassan Erfani
Theses and Dissertations
Increased vulnerability of water systems to extreme events and climate change is among the profound challenges facing the management of water resource systems around the world. Extreme events, including droughts, floods, and natural hazards have become more frequent and intensive, particularly in coastal regions. Floods, for instance, caused tens of billions of US dollars losses and put the lives of thousands in danger, globally. To cope with the adverse consequences of floods, a wide range of structural, non-structural, and emergency measures are studied and deployed by flood management sectors. Various flood simulation, mapping, and forecast systems have been developed to …
Efficient Scopeformer: Towards Scalable And Rich Feature Extraction For Intracranial Hemorrhage Detection Using Hybrid Convolution And Vision Transformer Networks, Yassine Barhoumi
Efficient Scopeformer: Towards Scalable And Rich Feature Extraction For Intracranial Hemorrhage Detection Using Hybrid Convolution And Vision Transformer Networks, Yassine Barhoumi
Theses and Dissertations
The field of medical imaging has seen significant advancements through the use of artificial intelligence (AI) techniques. The success of deep learning models in this area has led to the need for further research. This study aims to explore the use of various deep learning algorithms and emerging modeling techniques to improve training paradigms in medical imaging. Convolutional neural networks (CNNs) are the go-to architecture for computer vision problems, but they have limitations in mapping long-term dependencies within images. To address these limitations, the study explores the use of techniques such as global average pooling and self-attention mechanisms. Additionally, the …
Using Embedded Systems And Augmented Reality For Automated Aerial Refueling, Nathaniel A. Wilson
Using Embedded Systems And Augmented Reality For Automated Aerial Refueling, Nathaniel A. Wilson
Theses and Dissertations
The goal of automated aerial refueling (AAR) is to extend the range of unmanned aircraft. Control latency prevents a human from remotely controlling the receiving aircraft as it approaches a tanker. To conform with the size, weight, and power constraints of a small unmanned aircraft, an AAR system must execute in real-time on an embedded platform. This thesis explores the timing and computational performance of a NVIDIA Jetson AGX Orin to a state-of-the-art general-purpose computer using existing AAR algorithms. It also constructs an augmented reality framework as an intermediate step for testing vision-based AAR algorithms between virtual testing and expensive …
Deeptype: A Deep Neural Network Approach To Keyboard-Free Typing, Joshua V. Broekhuijsen
Deeptype: A Deep Neural Network Approach To Keyboard-Free Typing, Joshua V. Broekhuijsen
Theses and Dissertations
Textual data entry is an increasingly-important part of Human-Computer Interaction (HCI), but there is room for improvement in this domain. First, the keyboard -- a foundational text-entry device -- presents ergonomic challenges in terms of comfort and accuracy for even well-trained typists. Second, touch-screen smartphones -- some of the most ubiquitous mobile devices -- lack the physical space required to implement a full-size physical keyboard, and settle for a reduced input that can be slow and inaccurate. This thesis proposes and examines "DeepType" to begin addressing both of these problems in the form of a fully-virtual keyboard, realized through a …
An Augmented Reality Maintenance Assistant With Real-Time Quality Inspection On Handheld Mobile Devices, James Thomas Frandsen
An Augmented Reality Maintenance Assistant With Real-Time Quality Inspection On Handheld Mobile Devices, James Thomas Frandsen
Theses and Dissertations
With the advances of industry 4.0, augmented reality (AR) devices are being deployed across the manufacturing sector to enhance worker perception and efficiency. AR is often used to deliver spatially relevant work instructions on mobile devices for maintenance procedures on the factory floor. In these situations, workers use their mobile devices to view instructions in the form of 3D animations and annotations that directly overlay the equipment being maintained. Workers then follow the AR instructions and must ultimately rely on their own judgement and knowledge of the procedure as they progress from step to step. An AR assistant that could …
Development Of A 3d-Printed Microfluidic Droplet-On-Demand System For The Deterministic Encapsulation And Processing Of Biological Materials, Chandler A. Warr
Development Of A 3d-Printed Microfluidic Droplet-On-Demand System For The Deterministic Encapsulation And Processing Of Biological Materials, Chandler A. Warr
Theses and Dissertations
The growing threat of antimicrobial resistance is among the largest concerns in the world today. One method under development to combat this issue is the encapsulation of microbes in microfluidic droplets for single-cell testing. This method may be able to circumvent the need for a traditional positive cell culture which consumes the majority of the testing time using current diagnostic methods. This dissertation presents a method by which to deterministically encapsulate microbes using an artificial intelligence object detection algorithm and a Droplet-On-Demand microfluidic device. To accomplish this, the Droplet-On-Demand microfluidic device was first developed using a unique 3D-printing manufacturing method. …
Automated Pre-Play Analysis Of American Football Formations Using Deep Learning, Jacob Deloy Newman
Automated Pre-Play Analysis Of American Football Formations Using Deep Learning, Jacob Deloy Newman
Theses and Dissertations
Annotation and analysis of sports videos is a time consuming task that, once automated, will provide benefits to coaches, players, and spectators. American football, as the most watched sport in the United States, could especially benefit from this automation. Manual annotation and analysis of recorded video of American football games is an inefficient and tedious process. Currently, most college football programs focus on annotating offensive formation. As a first step to further research for this unique application, we use computer vision and deep learning to analyze an overhead image of a football play immediately before the play begins. This analysis …
Real Time Evaluation Of Boom And Drogue Occlusion With Aar, Xiaoyang Wu
Real Time Evaluation Of Boom And Drogue Occlusion With Aar, Xiaoyang Wu
Theses and Dissertations
In recent years, Unmanned Aerial Vehicles (UAV) have seen a rise in popularity. Various navigational algorithms have been developed as a solution to estimate a UAV’s pose relative to the refueler aircraft. The result can be used to safely automate aerial refueling (AAR) to improve UAVs’ time-on-station and ensure the success of military operations. This research aims to reach real-time performance using a GPU accelerated approach. It also conducts various experiments to quantify the effects of refueling boom/drogue occlusion and image exposure on the pose estimation pipeline in a lab setting.
Monocular Pose Estimation For Automated Aerial Refueling Via Perspective-N-Point, James C. Lynch
Monocular Pose Estimation For Automated Aerial Refueling Via Perspective-N-Point, James C. Lynch
Theses and Dissertations
Any Automated Aerial Refueling (AAR) solution requires the quick and precise estimation of the relative position and rotation of the two aircraft involved. This is currently accomplished using stereo vision techniques augmented by Iterative Closest Point (ICP), but requires post-processing to account for environmental factors such as boom occlusion. This paper proposes a monocular solution, combining a custom-trained single-shot object detection Convolutional Neural Network (CNN) and Perspective-n-Point (PnP) estimation to calculate a pose estimate with a single image. This solution is capable of pose estimation at contact point (22m) within 7cm of error and a rate of 10Hz, regardless of …
Considerations Using Iterative Closest Point In Presence Of Occlusions In Automated Aerial Refueling, Joel M. Miller
Considerations Using Iterative Closest Point In Presence Of Occlusions In Automated Aerial Refueling, Joel M. Miller
Theses and Dissertations
The United States Air Force is researching vision-based AAR and different methods for this actualization. Previous work has established a computer vision based pipeline with ICP. This work focuses on how ICP can become resilient to boom occlusion by minimizing errors and discusses the limitations of ICP in the face of occlusions. Specifically, we look at various filtering techniques to remove non-salient points. To register point clouds while maintaining real time interactivity, this work also presents a method for downsampling high resolution camera calibrations to preserve real-time processing and significantly decrease the vision pipeline latency.
Nonlinear Intelligent Model Predictive Control Of Mobile Robots, Benjamin Albia
Nonlinear Intelligent Model Predictive Control Of Mobile Robots, Benjamin Albia
Theses and Dissertations
This thesis presents a framework for an artificial neural network (ANN) model-based nonlinear model predictive control of mobile ground robots. A computer vision analysis module was first developed to extract quantitative position information from onboard camera feed with respect to a prescribed path. Various strategies were developed to construct nonlinear physical plant models for model predictive control (MPC), including the physics-based model (PBM), the ANN trained on PBM-generated data, the ANN trained on test-captured data, and the ANN initially trained on PBM-generated data and then retrained with captured data. All the models predict physical states and positions of the robot …
Visual Navigation And Control For Spacecraft Proximity Operations With Unknown Targets, Wyatt J. Harris
Visual Navigation And Control For Spacecraft Proximity Operations With Unknown Targets, Wyatt J. Harris
Theses and Dissertations
Many current and future spacecraft missions must conduct rendezvous and proximity operations (RPO) with resident space objects (RSOs). An important subset of spacecraft RPO that is yet to be demonstrated on-orbit involves final approach maneuvers with respect to RSOs where no information (such as geometry, inertia, relative velocity, etc.) is known about the target a priori, and no information is actively provided by the target during maneuvering. Such operation with respect to ‘unknown’ targets represents an important possible mission set for Department of Defense spacecraft and is the subject of this research. Two visual servoing frameworks capable of autonomously controlling …
Small-Target Detection And Observation With Vision-Enabled Fixed-Wing Unmanned Aircraft Systems, Hayden Matthew Morgan
Small-Target Detection And Observation With Vision-Enabled Fixed-Wing Unmanned Aircraft Systems, Hayden Matthew Morgan
Theses and Dissertations
This thesis focuses on vision-based detection and observation of small, slow-moving targets using a gimballed fixed-wing unmanned aircraft system (UAS). Generally, visual tracking algorithms are tuned to detect motion of relatively large objects in the scene with noticeably significant motion; therefore, applications such as high-altitude visual searches for human motion often ignore target motion as noise. Furthermore, after a target is identified, arbitrary maneuvers for transitioning to overhead orbits for better observation may result in temporary or permanent loss of target visibility. We present guidelines for tuning parameters of the Visual Multiple Target Tracking (Visual MTT) algorithm to enhance its …
Learning To Detect Pedestrian Flow In Traffic Intersections From Synthetic Data, Abhijit Baul
Learning To Detect Pedestrian Flow In Traffic Intersections From Synthetic Data, Abhijit Baul
Theses and Dissertations
Detecting pedestrian flow in different directions at at traffic-intersection has always been a challenging task. Challenges include different weather conditions, different crowd densities, occlusions, lack of available data, and so on. The emergence of deep learning and computer vision algorithms has shown promises to deal with these problems. Most of the recent works only focus on either detecting combined pedestrian flow or counting the total number of pedestrians. In this work, we have tried to detect not only combined pedestrian flow but also pedestrian flow indifferent directions. Our contributions are, 1) we are introducing a synthetic pedestrian dataset that we …
Stereo Camera Calibrations With Optical Flow, Joshua D. Larson
Stereo Camera Calibrations With Optical Flow, Joshua D. Larson
Theses and Dissertations
Remotely Piloted Aircraft (RPA) are currently unable to refuel mid-air due to the large communication delays between their operators and the aircraft. AAR seeks to address this problem by reducing the communication delay to a fast line-of-sight signal between the tanker and the RPA. Current proposals for AAR utilize stereo cameras to estimate where the receiving aircraft is relative to the tanker, but require accurate calibrations for accurate location estimates of the receiver. This paper improves the accuracy of this calibration by improving three components of it: increasing the quantity of intrinsic calibration data with CNN preprocessing, improving the quality …
Using Motion Capture And Augmented Reality To Test Aar With Boom Occlusion, Vincent J. Bownes
Using Motion Capture And Augmented Reality To Test Aar With Boom Occlusion, Vincent J. Bownes
Theses and Dissertations
The operational capability of drones is limited by their inability to perform aerial refueling. This can be overcome by automating the process with a computer vision solution. Previous work has demonstrated the feasibility of automated aerial refueling (AAR) in simulation. To progress this technique to the real world, this thesis conducts experiments using real images of a physical aircraft replica and a motion capture system for truth data. It also compares the error between the real and virtual experiments to validate the fidelity of the simulation. Results indicate that the current technique is effective on real images and that the …
Accelerating Point Set Registration For Automated Aerial Refueling, Ryan M. Raettig
Accelerating Point Set Registration For Automated Aerial Refueling, Ryan M. Raettig
Theses and Dissertations
The goal of AAR is to control the tanker boom to safely refuel a receiving aircraft with no input or aid from the boom operator. To achieve this, the pose of the receiver relative to the tanker must be known. Point set registration is a fundamental issue used to estimate the relative pose of an object in an environment. However, it's likely a computational bottleneck of a vision processing pipeline. In addition, the matching of each sensed point with a closest truth point, nearest neighbor matching, is the most costly portion of the point set registration process. For this reason, …
Object Detection With Deep Learning To Accelerate Pose Estimation For Automated Aerial Refueling, Andrew T. Lee
Object Detection With Deep Learning To Accelerate Pose Estimation For Automated Aerial Refueling, Andrew T. Lee
Theses and Dissertations
Remotely piloted aircraft (RPAs) cannot currently refuel during flight because the latency between the pilot and the aircraft is too great to safely perform aerial refueling maneuvers. However, an AAR system removes this limitation by allowing the tanker to directly control the RP A. The tanker quickly finding the relative position and orientation (pose) of the approaching aircraft is the first step to create an AAR system. Previous work at AFIT demonstrates that stereo camera systems provide robust pose estimation capability. This thesis first extends that work by examining the effects of the cameras' resolution on the quality of pose …
Maximizing Accuracy Through Stereo Vision Camera Positioning For Automated Aerial Refueling, Kirill A. Sarantsev
Maximizing Accuracy Through Stereo Vision Camera Positioning For Automated Aerial Refueling, Kirill A. Sarantsev
Theses and Dissertations
Aerial refueling is a key component of the U.S. Air Force strategic arsenal. When two aircraft interact in an aerial refueling operation, the accuracy of relative navigation estimates are critical for the safety, accuracy and success of the mission. Automated Aerial Refueling (AAR) looks to improve the refueling process by creating a more effective system and allowing for Unmanned Aerial Vehicle(s) (UAV) support. This paper considers a cooperative aerial refueling scenario where stereo cameras are used on the tanker to direct a \boom" (a large, long structure through which the fuel will ow) into a port on the receiver aircraft. …
Use Of Lidar In Automated Aerial Refueling To Improve Stereo Vision Systems, Michael R. Crowl
Use Of Lidar In Automated Aerial Refueling To Improve Stereo Vision Systems, Michael R. Crowl
Theses and Dissertations
The United States Air Force (USAF) executes five Core Missions, four of which depend on increased aircraft range. To better achieve global strike and reconnaissance, unmanned aerial vehicles (UAVs) require aerial refueling for extended missions. However, current aerial refueling capabilities are limited to manned aircraft due to technical difficulties to refuel UAVs mid-flight. The latency between a UAV operator and the UAV is too large to adequately respond for such an operation. To overcome this limitation, the USAF wants to create a capability to guide the refueling boom into the refueling receptacle. This research explores the use of light detection …
Emotion Recognition Using Facial Feature Extraction, Demiyan Smirnov
Emotion Recognition Using Facial Feature Extraction, Demiyan Smirnov
Theses and Dissertations
Computerized emotion recognition systems can be powerful tools to help solve problems in a wide range of fields including education, healthcare, and marketing. Existing systems use digital images or live video to track facial expressions on a person's face and deduce that person's emotional state. The research presented in this thesis explores combinations of several facial feature extraction techniques with different classifier algorithms. Namely, the feature extraction techniques used in this research were Discrete Cosine/Sine Transforms, Fast Walsh-Hadamard Transform, Principle Component Analysis, and a novel method called XPoint. Features were extracted from both global (using the entire facial image) and …
Infrared And Electro-Optical Stereo Vision For Automated Aerial Refueling, William E. Dallmann
Infrared And Electro-Optical Stereo Vision For Automated Aerial Refueling, William E. Dallmann
Theses and Dissertations
Currently, Unmanned Aerial Vehicles are unsafe to refuel in-flight due to the communication latency between the UAVs ground operator and the UAV. Providing UAVs with an in-flight refueling capability would improve their functionality by extending their flight duration and increasing their flight payload. Our solution to this problem is Automated Aerial Refueling (AAR) using stereo vision from stereo electro-optical and infrared cameras on a refueling tanker. To simulate a refueling scenario, we use ground vehicles to simulate a pseudo tanker and pseudo receiver UAV. Imagery of the receiver is collected by the cameras on the tanker and processed by a …
Satellite Articulation Sensing Using Computer Vision, David H. Curtis
Satellite Articulation Sensing Using Computer Vision, David H. Curtis
Theses and Dissertations
Autonomous on-orbit satellite servicing benefits from an inspector satellite that can gain as much information as possible about the primary satellite. This includes performance of articulated objects such as solar arrays, antennas, and sensors. A method for building an articulated model from monocular imagery using tracked feature points and the known relative inspection route is developed. Two methods are also developed for tracking the articulation of a satellite in real-time given an articulated model using both tracked feature points and image silhouettes. Performance is evaluated for multiple inspection routes and the effect of inspection route noise is assessed. Additionally, a …
Visual Servoing For Precision Shipboard Landing Of An Autonomous Multirotor Aircraft System, Jesse Stewart Wynn
Visual Servoing For Precision Shipboard Landing Of An Autonomous Multirotor Aircraft System, Jesse Stewart Wynn
Theses and Dissertations
Precision landing capability is a necessary development that must take place before unmanned aircraft systems (UAS) can realize their full potential in today's modern society. Current multirotor UAS are heavily reliant on GPS data to provide positioning information for landing. While generally accurate to within several meters, much higher levels of accuracy are needed to ensure safe and trouble-free operations in several UAS applications that are currently being pursued. Examples of these applications include package delivery, automatic docking and recharging, and landing on moving vehicles. The specific problem we consider is that of precision landing of a multirotor unmanned aircraft …
Integrity Monitoring For Automated Aerial Refueling: A Stereo Vision Approach, Thomas R. Stuart
Integrity Monitoring For Automated Aerial Refueling: A Stereo Vision Approach, Thomas R. Stuart
Theses and Dissertations
Unmanned aerial vehicles (UAVs) increasingly require the capability to y autonomously in close formation including to facilitate automated aerial refueling (AAR). The availability of relative navigation measurements and navigation integrity are essential to autonomous relative navigation. Due to the potential non-availability of the global positioning system (GPS) during military operations, it is highly desirable that relative navigation can be accomplished without the use of GPS. This paper develops two algorithms designed to provide relative navigation measurements solely from a stereo image pair. These algorithms were developed and analyzed in the context of AAR using a stereo camera system modeling that …
A Robust Synthetic Basis Feature Descriptor Implementation And Applications Pertaining To Visual Odometry, Object Detection, And Image Stitching, Lindsey Ann Raven
A Robust Synthetic Basis Feature Descriptor Implementation And Applications Pertaining To Visual Odometry, Object Detection, And Image Stitching, Lindsey Ann Raven
Theses and Dissertations
Feature detection and matching is an important step in many object tracking and detection algorithms. This paper discusses methods to improve upon previous work on the SYnthetic BAsis feature descriptor (SYBA) algorithm, which describes and compares image features in an efficient and discreet manner. SYBA utilizes synthetic basis images overlaid on a feature region of interest (FRI) to generate binary numbers that uniquely describe the feature contained within the FRI. These binary numbers are then used to compare against feature values in subsequent images for matching. However, in a non-ideal environment the accuracy of the feature matching suffers due to …
Improving Real-World Performance Of Vision Aided Navigation In A Flight Environment, Donald T. Venable
Improving Real-World Performance Of Vision Aided Navigation In A Flight Environment, Donald T. Venable
Theses and Dissertations
The motivation of this research is to fuse information from an airborne imaging sensor with information extracted from satellite imagery in order to provide accurate position when GPS is unavailable for an extended duration. A corpus of existing geo-referenced satellite imagery is used to create a key point database. A novel algorithm for recovering coarse pose using by comparing key points extracted from the airborne imagery to the reference database is developed. This coarse position is used to bootstrap a local-area geo-registration algorithm, which provides GPS-level position estimates. This research derives optimizations for existing local-area methods for operation in flight …
Quantifying Computer Vision Model Quality Using Various Processing Techniques, Samantha Anna Ruggles
Quantifying Computer Vision Model Quality Using Various Processing Techniques, Samantha Anna Ruggles
Theses and Dissertations
Recently, the use of unmanned aerial vehicles (UAVs) has increased in popularity across several industries. Most notable, however, is the impact that this technology has had in research at academic institutions worldwide. As the technology for UAVs has improved, with that comes easier to operate, more accessible equipment. UAVs have been used in various types of applications and are quickly becoming a preferred method of studying and analyzing a site. Currently, the most common use of a UAV is to monitor a location of interest to a researcher that is difficult to gain access to otherwise. The UAV can be …
Towards Automated Aerial Refueling: Real Time Position Estimation With Stereo Vision, Bradley D. Denby
Towards Automated Aerial Refueling: Real Time Position Estimation With Stereo Vision, Bradley D. Denby
Theses and Dissertations
Aerial refueling is essential to the United States Air Force (USAF) core mission of rapid global mobility. However, in-flight refueling is not available to remotely piloted aircraft (RPA) or unmanned aerial systems (UAS). As reliance on drones for intelligence, surveillance, and reconnaissance (ISR) and other USAF core missions grows, the ability to automate aerial refueling for such systems becomes increasingly critical. New refueling platforms include sensors that could be used to estimate the relative position of an approaching aircraft. Relative position estimation is a key component to solving the automated aerial refueling (AAR) problem. Analysis of data from a one-seventh …