The purpose of this thesis is to extend an existing autopilot with automatic takeoff and landing algorithms for small fixed wing unmanned aircrafts. The work has been done from a systems engineering perspective and as for solution candidates this thesis has a bias towards solutions utilizing fuzzy logic. The coveted promises of fuzzy logic was primarily the idea to have a design that was easily tunable with very little knowledge beyond flight experience for a particular aircraft. The systems engineering perspective provided a way to structure and reason about the project where the problem has been decoupled from different solutions and the work has been divided in a way that would allow multiple aspects of the project to be pursued simultaneously. Though the fuzzy logic controllers delivered functional solutions the promises related to ease of tuning was not fulfilled in a landing context. This might have been a consequence of the designs attempted but in the end a simpler solution outperformed the implemented fuzzy logic controllers. Takeoff did not present the same issues in tuning but did require some special care to handle the initial low airspeeds in an hand launch.

The thesis is focused on aircraft flight level control in case when the location of center of gravity changes during flight. The theoretical part of the thesis describes basics of aerodynamics, which are necessary to understand airplane's behavior and its control theory. Basics of state theory and stability of systems, as it is used for design of linear model. This part also mentions mathematical equations of nonlinear model of business jet and discusses conventional and adaptive methods used to design autopilot parameters. Several autopilots were designed in practical part of the thesis. The most important part is the logic used to determine location of center of gravity of the airplane. The models use nonlinear model of an airplane that better represents the real environment and conditions.

At the beginning this master's thesis includes of a comprehensive review of aircraft accidents in this category, 2-6-digit aircraft for passenger transport. Since this work focused on autopilot, so naturally there is a basic overview of most common autopilots, which can be found in these aircraft now, but in the future. Functional hazard analysis (FHA) for the 4-seater plane for passenger services primarily investigates cases of catastrophic malfunction, which in most cases accompanied by the likelihood taken from different databases. The airplane, which is created for this analysis will preferably equipped with instruments for IFR flights. There is also a brief overview of the regulations necessary for the installation of these systems in the airplane. At the end of this work is to design the dashboard, a design layout of equipment for future aircraft, with an emphasis on maximum transparency.

This thesis is focused on a project of all metal aircraft by UL-2 and LSA rules. The background research of aircrafts in existing category has been made in the market. The concept, with whom this thesis deals with, has been projected thanks to this analysis. The second part of the thesis is focused on avionics equipments of aircrafts. Market analysis has been made and the way of medernizing small sports airfts' equipment in categories UL and LSA has been projected.

This thesis describes design and implementation of SW architecture for autopilot of unmanned aircraft including flight data logging, integration of automatically generated code from Matlab Simulink and communication with ground station.

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The work in this thesis is concerned with the generation of Lumped Parameter Models (LPM) for two, slender, torpedo shaped, X-fin craft. This process involves the use of CFD to simulate captive maneuvers that are normally performed using test equipment in the field. These captive maneuvers are refereed to as planar motion mechanisms (PMM), and when simulated through CFD are refereed to as virtual planar motion mechanisms (VPMM). The results from VPMM are used to determine the hydrodynamic derivatives that inform the LPM. There was some inconsistency in the VPMM data based on the frequency and amplitude that the VPMM was run. A brief study was run to look at this effect. Afterwards, Open and closed loop, autopilot assisted, maneuvers are implemented and performed using the LPM model through Simulink. Results of these maneuvers are analyzed for craft stability. Additionally, comparisons of LPM maneuvers to field data are performed. Critiques of the craft stability and effect of the autopilot are made. / Master of Science / The work carried out in this thesis involves the creation of a physics based model of an underwater craft. This physics based model is informed through characteristics determined by running computational fluid dynamics (CFD) simulations. The benefit of such a model, is the simplification from CFD to a 6 degree of freedom (6-DOF) lumped parameter model (LPM). These physics models, LPM, are generated for two particular craft of interest. One craft is an existing design used by NUWC (named Tonnetto), while the other design is one generated to be similar in shape and size to the NUWC craft (named Hokie). Computer simulated maneuvers are carried out using these models to asses craft stability and performance. An autopilot is implemented into the models for some of these simulations to see its affects on the crafts performance. Additionally, these simulated maneuvers are compared to field data collected by NUWC.

<div>Unmanned aerial vehicles (UAVs) have gained more attention in recent years because of their ability to execute various missions. However, recent works have identified vulnerabilities in UAV systems that make them more readily prone to cyberattacks. In this work, the vulnerabilities in the communication channel between the UAV and ground control station are exploited to implement cyberattacks, specifically, the denial of service and false data injection attacks. Unlike other related studies that implemented attacks in simulations, we demonstrate the actual implementation of these attacks on a Holybro S500 quadrotor with PX4 autopilot firmware and MAVLink communication protocol.</div><div><br></div><div>The goal was to create a lightweight intrusion detection system (IDS) that leverages recurrent neural networks (RNNs) to accurately detect cyberattacks, even when implemented on a resource-constrained platform. Different types of RNNs, including simple RNNs, long short-term memory, gated recurrent units, and simple recurrent units, were trained and tested on actual experimental data. A recursive feature elimination approach was carried out on selected features to remove redundant features and to create a lighter RNN IDS model. We also studied the resource consumption of these RNNs on an Arduino Uno board, the lowest-cost companion computer that can be implemented with PX4 autopilot firmware and Pixhawk autopilot boards. The results show that a simple RNN has the best accuracy while also satisfying the constraints of the selected computer.<br></div>

Nonlinear stabilization and control autopilots are capable of sustaining nominal performance throughout the entire fight envelope an interceptor missile may encounter during hostile engagements and require no gain scheduling to maintain autopilot stability. Due to non minimum phase conditions characteristic of tail controlled missile airframes, a separation of time scales within the dynamic equations of motion between rotational and translational differential equations was enforced to overcome unstable effects of non minimum phase. Dynamic inversion techniques are then applied to derive linearizing equations which, when injected forward into the plant result in a fully controllable linear system. Objectives of the two time scale control architecture are to stabilize vehicle rotational rates while at the same time controlling acceleration within the lateral plane of the vehicle under rapidly increasing dynamic pressure. Full 6 degree of freedom dynamic terms including all coriolis accelerations due to translational and rotational dynamic coupling have been taken into account in the inversion process. The result is a very stable, nonlinear autopilot with fixed control gains fully capable of stable nonlinear missile control. Several actuator systems were also designed to explore the destabilizing effects second order nonlinear actuator characteristics can have on nonlinear autopilot designs.

No description available.