Operator responsiveness to critical alarm/alert display systems must rely on faster and safer behavioral responses in order to ensure mission success in complex environments such as the operator station of an Unmanned Aerial System (UAS). An important design consideration for effective UAS interfaces is how to map these critical alarm/alert display systems to an appropriate sensory modality (e.g., visual or auditory) (Sarter, 2006). For example, if an alarm is presented during a mission in a modality already highly taxed or overloaded, this can result in increased response time (RT), thereby decreasing operator performance (Wickens, 1976). To overcome this problem, system designers may allow the switching of the alarm display from a highly-taxed to a less-taxed modality (Stanney et al., 2004). However, this modality switch may produce a deleterious effect known as the Modality Shifting Effect (MSE) that erodes the expected performance gain (Spence & Driver, 1997). The goal of this research was to empirically examine a technique called bridging which allows the transitioning of a cautionary alarm display from one modality to another while simultaneously counteracting the Modality Shifting Effect. Sixty-four participants were required to complete either a challenging visual or auditory task using a computer-based UAS simulation environment while responding to both visual and auditory alarms. An approach was selected which utilized two 1 (task modality) x 2 (switching technique) ANCOVAs and one 2 (modality) x 2 (technique) ANCOVA, using baseline auditory and visual RT as covariates, to examine differences in alarm response times when the alert modality was changed abruptly or with the bridging technique from a highly loaded sensory channel to an underloaded sensory channel. It was hypothesized that the bridging technique condition would show faster response times for a new unexpected modality versus the abrupt switching condition. The results indicated only a marginal decrease in response times for the auditory alerts and a larger yet not statistically significant effect for the visual alerts; results were also not statistically significant for the analysis collapsed across modality. Findings suggest that there may be some benefit of the bridging technique on performance of alarm responsiveness, but further research is still needed before suggesting generalizable design guidelines for switching modalities which can apply in a variety of complex human-machine systems.

UAV units are by many researchers and aviation specialists considered the future and cutting edge of modern flight technology. This thesis discusses methods for efficient autonomous environmental mapping in a multi-agent domain. An algorithm that emphasizes on team work by sharing the agents local map information and exploration intentions is presented as a solution to the mapping problem. General theories on how to model and implement rational autonomous behaviour for UAV agents are presented. Three different human and tactical behaviour modeling techniques are evaluated. The author found the CxBR paradigm to be the most interesting approach. Also, in order to test and quantify the theories presented in this thesis a simulation environment was developed. This simulation software allows for UAV agents to operate in a visual 3-D environment with mountains, other various terrain types, danger points and enemies to model unexpected events.

We present an exploration that surveys the strengths and weaknesses of various 3D spatial interaction techniques, in the context of directly manipulating an Unmanned Aerial Vehicle (UAV). Particularly, a study of touch- and device- free interfaces in this domain is provided. 3D spatial interaction can be achieved using hand-held motion control devices such as the Nintendo Wiimote, but computer vision systems offer a different and perhaps more natural method. In general, 3D user interfaces (3DUI) enable a user to interact with a system on a more robust and potentially more meaningful scale. We discuss the design and development of various 3D interaction techniques using commercially available computer vision systems, and provide an exploration of the effects that these techniques have on an overall user experience in the UAV domain. Specific qualities of the user experience are targeted, including the perceived intuition, ease of use, comfort, and others. We present a complete user study for upper-body gestures, and preliminary reactions towards 3DUI using hand-and-finger gestures are also discussed. The results provide evidence that supports the use of 3DUI in this domain, as well as the use of certain styles of techniques over others.

This paper presents a flying qualities built-in-test for UAS application with the scope limited to the longitudinal 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 AVO in a color-coded, easy to interpret display. While SID algorithms have been flying in vehicles with adaptive control schemes, vehicles with other schemes (such as classical feedback) lack this built-in self assessment tool. In addition, adaptive control SID results are not analyzed and displayed but instead used internally. This work intends to extend this self-assessment option to all UASs regardless of control scheme as a “plug-and-play” add-on by building a reliable and robust tool that requires little tuning.

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 of a lead UAV in real-time from video captured by a camera on-board the following UAV. The software, written using OpenCV computer vision libraries and executed on an embedded single-board computer, uses the Efficient Perspective-n-Point algorithm to compute the 3-D pose from a set of 2-D image points. High-intensity, red, light emitting diodes (LEDs) were affixed to specific locations on the lead aircraft’s airframe to simplify the task if extracting the 2-D image points from video. Next, the following vehicle was controlled by modifying a commercially available, open source, waypoint-guided autopilot to navigate using the relative state vector provided by the vision software. A custom Hardware-In-Loop (HIL) simulation station was set up and used to derive the required localization update rate for various flight patterns and levels of atmospheric turbulence. HIL simulation showed that it should be possible to maintain formation, with a vehicle separation of 50 ± 6 feet and localization estimates updated at 10 Hz, for a range of flight conditions. Finally, the system was implemented into low-cost remote controlled aircraft and flight tested to demonstrate formation convergence to 65.5 ± 15 feet of separation.

A method for sizing remotely powered unmanned aerial vehicles is presented to augment the conventional design process. This method allows for unconventionally powered aircraft to become options in trade studies during the initial design phase. A design matrix is created that shows where, and if, a remotely powered vehicle fits within the design space. For given range and power requirements, the design matrix uses historical data to determine whether an internal combustion or electrical system would be most appropriate. Trends in the historical data show that the break in the design space between the two systems is around 30 miles and 1 kW. Electrical systems are broken into subcategories of onboard energy sources and remote power sources. For this work, only batteries were considered as an onboard energy source, but both lasers and microwaves were considered for remote power transmission methods. The conventional sizing method is adjusted to so that it is based on energy consumption, instead of fuel consumption. Using the manner in which microwaves and laser propagate through the atmosphere, the weight fraction of a receiving apparatus is estimated. This is then used with the sizing method to determine the gross takeoff weight of the vehicle. This new sizing method is used to compare battery systems, microwave systems, and laser systems.

This document contains the details of a study conducted to determine an effective performance flight test approach specifically for small Unmanned Aircraft Systems (sUAS). This was done by taking proven procedures and documentation from the FAA and the Air Force for manned aircraft and tailoring them specifically for use with sUAS flight test programs. A ‘sUAS Flight Testing Handbook’ was created from the proceedings to aid commercial organizations and recreational developers conducting sUAS research without access to flight test experience. A performance flight test program was conducted with the AeroVironment RQ-20 Puma sUAS using the developed approach to verify that the ‘sUAS Flight Test Handbook’ was effective at guiding the test program safely and effectively. The development of the handbook, the results of the Puma Flight Test Program (PFTP), and the instructional ‘sUAS Flight Test Handbook’ itself are detailed throughout this report. The handbook includes a set of recommendations developed from experience with the PFTP that apply to both commercial and recreational developers of sUAS. A set of documentation is also provided in the form of instructional templates that plan the test program, report the results, and allow sUAS performance flight testing to be carried out safely and effectively.

Despite the first unmanned aerial vehicle (UAV) mission being flown on Aug 22 1849 to bomb Venice UAVs have only recently began to modernize into sophisticated tools beyond simple aerial vehicles. With an increasing number of potential applications, such as cargo delivery, communications, search and rescue, law enforcement, and homeland security, the need for appropriate UAV technology advancement also arose. Here, the development of a low-cost collision avoidance system is described. Hardware was tested and selected based on predetermined constraints and goals. Additionally, a variety of potential functions were explored and assessed at their effectiveness in preventing a collision of a UAV with mountainous terrain. Simulations were conducted using Cloud Cap’s Piccolo autopilot in conjunction with Matlab. Based on these simulations, a set of potential functions was selected to be used with the chosen hardware on subsequent UAV-development-related projects.

The current uses of unmanned aerial vehicles (UAVs) in wildland firefighting center around mapping, scouting, and firing operations. These operations and additional operations are often held back by lack of range and lift capacity of current UAV options. Software design tools were developed in this research to aid in designing a UAV for wildland firefighting. The tools help create a mission profile, estimate the mass of the UAV, select a motor and rotor, select a battery, and generate and analyze a finite element (FE) sector model. These tools leverage parametric analysis and studying existing hardware to create a design. The FE model is generated based on the mission profile, a motor and rotor, and battery as design parameters and a set of design variables. The tools developed for creating a mission profile, estimating mass, selecting a motor and rotor, and selecting a battery successfully aid the preliminary design of an octocopter, hexacopter, and quadcopter. The FE tool was designed around an octocopter's geometry, which leads to complications in generating FE models for a hexacopter or quadcopter. Recommendations were made for altering the FE tool to account for hexacopters and quadcopters. Other recommendations were made to support future work in creating an optimized design of a wildland firefighting UAV. / Master of Science / The use of multirotor UAVs in various industries is rapidly expanding. One industry that currently uses UAVs but is limited in their capabilities is wildland firefighting. Wildland firefighters use UAVs for scouting, mapping, and firing operations. Scouting includes finding road access to the fire, finding water sources, searching for spot fires, and many other applications. Mapping is typically done to understand the size of the fire. Firing operations are conducted to start small, controlled fires to remove fuel from the fires path. However, these operations as well as future applications of UAVs are often limited by the flight time and the lifting capabilities current UAV options offer. Tools were developed in this research to create a preliminary design of a UAV for wildland firefighting. The design parameters and variables of the UAV design are outlined throughout the tools. The tools allow for compiling mission requirements, selecting motors/rotors and a battery to use in the UAV, and a preliminary structural analysis of the UAV design. The preliminary structural analysis includes extracting stresses, strains, and displacements experienced through a simplified mission as well as the natural frequencies of the finite element sector model. The design of octocopters, hexacopters, and quadcopters were explored using the set of design tools. The tools were successfully in selecting components for each style of UAV and at the preliminary structural analysis of the octocopter design. However, the structural analysis was not able to be conducted for the hexacopter and quadcopter design due to geometric conditions in the finite element model.

The primary objective of this master's thesis is to examine a new version of a power unit currently utilized in an unmanned aerial vehicle and develop a simulation model of the power unit. The theoretical groundwork needed for developing a model has been presented, describing components used and the function of the different subsystems. The development of a model is done in the simulation environment of Simscape. Measurements were preformed on the physical prototype of the power unit. These measurements were used to verify the simulation. The results of the simulations and the measurements are presented at the end of the thesis, confirming the simulation model's validity.