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Full-Text Articles in Navigation, Guidance, Control and Dynamics
The Navigation Potential Of Ground Feature Tracking, Guner Mutlu
The Navigation Potential Of Ground Feature Tracking, Guner Mutlu
Theses and Dissertations
This research effort examines the reduction of error in inertial navigation aided by vision. This is part of an effort focused on navigation in a GPS denied environment. The navigation concept examined here consists of two main steps. First, extract the position of a tracked ground object using vision and geo-locate it in 3 dimensional navigation frame. In this first step multiple positions of the UAV are assumed known; think of a synthetic aperture. The only information about the tracked ground objects/features is the unit vector that points to the objects from the center of the camera. Two such vectors …
Failure Detection Of A Pseudolite-Based Reference System Using Residual Monitoring, Michael A. Ciampa
Failure Detection Of A Pseudolite-Based Reference System Using Residual Monitoring, Michael A. Ciampa
Theses and Dissertations
The 746th TS uses a flight reference system referred to as the Central Inertial and GPS Test Facility (CIGTF) Reference System (CRS). Currently the CRS is the modern standard flight reference system for navigation testing, but high accuracy is dependent on the availability of GPS. A pseudolite system is currently being developed to augment the CRS and supply the capability to maintain high accuracy navigation under normal and jamming conditions. Pseudolite measurements typically contain cycle slips and other errors (such as multipath, tropospheric error, measurement noise) that can affect reliability. Past work relied on the receiver-reported signal-to-noise (SNR) value to …
Fusion Of Inertial Sensors And Orthogonal Frequency Division Multiplexed (Ofdm) Signals Of Opportunity For Unassisted Navigation, Jason G. Crosby
Fusion Of Inertial Sensors And Orthogonal Frequency Division Multiplexed (Ofdm) Signals Of Opportunity For Unassisted Navigation, Jason G. Crosby
Theses and Dissertations
The advent of the global positioning system (GPS) has provided worldwide high-accuracy position measurements. However, GPS may be rendered unavailable by jamming, disruption of satellites, or simply by signal shadowing in urban environments. Thus, this thesis considers fusion of Inertial Navigation Systems (INS) and Orthogonal Frequency Division Multiplexed (OFDM) signals of opportunity (SOOP) for navigation. Typical signal of opportunity navigation involves the use of a reference receiver and uses time difference of arrival (TDOA) measurements. However, by exploiting the block structure of OFDM communication signals, the need for the reference receiver is reduced or possibly removed entirely. This research uses …
Model-Based Control Using Model And Mechanization Fusion Techniques For Image-Aided Navigation, Constance D. Hendrix
Model-Based Control Using Model And Mechanization Fusion Techniques For Image-Aided Navigation, Constance D. Hendrix
Theses and Dissertations
Unmanned aerial vehicles are no longer used for just reconnaissance. Current requirements call for smaller autonomous vehicles that replace the human in high-risk activities. Many times these activities are performed in GPS-degraded environments. Without GPS providing today's most accurate navigation solution, autonomous navigation in tight areas is more difficult. Today, image-aided navigation is used and other methods are explored to more accurately navigate in such areas (e.g., indoors). This thesis explores the use of inertial measurements and navigation solution updates using cameras with a model-based Linear Quadratic Gaussian controller. To demonstrate the methods behind this research, the controller will provide …
Communication Free Robot Swarming, Zachary C. Gray
Communication Free Robot Swarming, Zachary C. Gray
Theses and Dissertations
As the military use of unmanned aerial vehicles increases, a growing need for novel strategies to control these systems exists. One such method for controlling many unmanned aerial vehicles simultaneously is the through the use of swarm algorithms. This research explores a swarm robotic algorithm developed by Kadrovach implemented on Pioneer Robots in a real-world environment. An adaptation of his visual sensor is implemented using stereo vision as the primary method of sensing the environment. The swarm members are prohibited from explicitly communicating other than passively through the environment. The resulting implementation produces a communication free swarming algorithm. The algorithm …
Automated Knowledge Generation With Persistent Surveillance Video, Daniel T. Schmitt
Automated Knowledge Generation With Persistent Surveillance Video, Daniel T. Schmitt
Theses and Dissertations
The Air Force has increasingly invested in persistent surveillance platforms gathering a large amount of surveillance video. Ordinarily, intelligence analysts watch the video to determine if suspicious activities are occurring. This approach to video analysis can be a very time and manpower intensive process. Instead, this thesis proposes that by using tracks generated from persistent video, we can build a model to detect events for an intelligence analyst. The event that we chose to detect was a suspicious surveillance activity known as a casing event. To test our model we used Global Positioning System (GPS) tracks generated from vehicles driving …