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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

High Bandwidth Control of a Small Aerial Vehicle / Hög bandbreddsreglering av en liten luftfarkost

Blomberg, Magnus January 2015 (has links)
Small aerial vehicles such as quad-rotors have been widely used commercially, for research and for hobby for the last decade with use still growing. The high interest is mainly due to the vehicles being small, simple, cheap and versatile. Among rigid body dynamics fast dynamics exist cohering to motors and other fast actuators. A linear quadratic control design technique is here investigated. The design technique suggests that the linear quadratic controller can be designed with penalties on the slow states only. The fast dynamics are modeled but the states are not penalised in the linear quadratic design. The design technique is here applied and evaluated. The results show that this in several cases is a suitable design technique for linear quadratic control design. MATLAB and Simulink have been widely used for design and implementation of control systems. With additional toolboxes these control systems can be compiled to and run on remote computers. Small, lightweight computers with high computational capacity are now easily accessible. In this thesis an avionics solution based on a small, powerful computer is presented. Simulink models can be compiled and transferred to the computer from the Simulink environment. The result is a user friendly way of rapid prototyping and evaluation of control systems.
2

Design of a Semi-Autonomous Quadrotor Aircraft

Hickle, Mark, Wilson, Alexander, Kientzy, Joshua, Myers, Matthew 10 1900 (has links)
ITC/USA 2012 Conference Proceedings / The Forty-Eighth Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2012 / Town and Country Resort & Convention Center, San Diego, California / This paper describes the design and construction of a semi-autonomous quadrotor aircraft approximately 1 meter in diameter. Because of the mechanical simplicity of the aircraft, the design challenges primarily centered on the electrical and computer engineering (ECE) tasks, and was used as a capstone design experience in an undergraduate ECE program. An onboard microcontroller based system uses a network of digital sensors and differential thrust for autonomous attitude control. A wireless telemetry and command link allows a user to monitor the vehicle, control its direction of flight, and for flight safety control.
3

Design Optimization of a Coaxial Heavy-Lift VTOL UAS

Ouwerkerk, Justin January 2017 (has links)
No description available.
4

Simulation and Integration of a 6-DOF Controllable Multirotor Vehicle

Deans, Collin Andrew 07 August 2020 (has links)
The purpose of this thesis is to develop an existing design of a fully controllable multi-rotor vehicle toward simulating small satellite dynamics, enabling technology development to be accelerated and component failure risks to be mitigated by providing a testing platform with dynamics similar to those of small satellites in orbit. Evaluating dynamics-sensitive software and hardware components for use in small satellite operations has typically been relegated to simulated or physically constrained testing environments. More recently, researchers have begun using multi-rotor aerial vehicles to mimic the orbital motion of such satellites, further increasing simulation fidelity. The dynamical nature of multi-rotor vehicles allows them to accurately simulate the translational dynamics of a small satellite, but they struggle to accurately simulate rotational dynamics, as conventional multi-rotor vehicles' translational and rotational dynamics are coupled. In this thesis, an optimal design for a multi-rotor vehicle independently controllable in all six degrees of freedom is evaluated as a suitable simulation platform. The design of the proposed physical system is discussed and progress toward its construction is demonstrated. To facilitate future research endeavors, a simulation of the vehicle in a software-in-the-loop environment, using the Gazebo dynamics simulator, is developed and its performance evaluated. This simulation is then used to evaluate the vehicle's feasibility as a small-satellite dynamics simulator by tasking it with tracking dynamic position and attitude time histories representative of a small satellite. / Master of Science / When developing a spacecraft, it can be difficult to accurately test software and hardware that are sensitive to the spacecraft's motion. This difficulty arises because the space environment experienced by orbiting spacecraft allows them to move and rotate freely, and recreating this freedom of motion on earth requires large, expensive, and difficult-to-access test equipment. To make this testing more accessible, researchers have begun using quadcopter drones to mimic some aspects of a spacecraft's motion. While quadcopters can move like an orbiting spacecraft can, their designs do not allow them to rotate like an orbiting spacecraft can, thus providing an incomplete recreation of spacecraft motion. To correct this shortcoming, an existing drone design that is able to move and rotate simultaneously without fear of crashing is developed, with progress shown toward its construction. A software simulation of the drone is developed to help future researchers test software and algorithms before flying it on the physical drone. The simulation is then used to see how well the drone design can recreate the motions that a small spacecraft would experience.
5

Computer-Aided Design Software for Torsional Analysis

Griffin, Timothy R. 23 March 1998 (has links)
The goal of this research has been the development of an effective design tool for torsional analysis. In the hopes of achieving this goal the computer program, Torsion 1, has been created. This torsional transfer matrix program provides the user with the ability to easily model multi-rotor systems using a simple user-interface. The program is capable of modeling such components or system characteristics as continuously distributed mass, viscous and structural damping, vibration absorbers, and gear meshes with gear tooth flexibility. The analysis capabilities of the program include forcedresponse and free-vibration analyses. The forced-response analysis module is capable of determining a system’s response to a static or harmonic torsional load. The free-vibration analysis module allows is capable of determining the eigenvalues and eigenvectors for damped and undamped systems. This thesis includes an explanation of the multi-rotor transfer matrix technique employed in Torsion 1. The derivation of transfer matrices for visco-elastic vibration absorbers, pendulum absorbers, flexible gear meshes, and planetary gear trains are included in this work. Finally, the validity of the program results is verified with a set of benchmark examples. / Master of Science
6

Full-Pose Estimation and Tracking Control for a Multi-Rotor Aircraft Package Exchange

Smith, Trent P. 01 August 2019 (has links)
In this work, research to develop algorithms for a package exchange maneuver between two quad-rotor aircraft is presented. First, the development of tools used for this research is discussed. Second, a controller is designed that synchronizes the flight paths and motion of two quad-rotor robots. The controller is used to guide a designated follower quad-rotor to follow a leader aircraft’s position and orientation. The follower aircraft is equipped with a simple mechanical manipulator to compensate for limitations in the aircrafts maneuverability. finally, a sensor architecture study for relative navigation of Unmanned Aerial Vehicles (UAV) is presented. The architecture study presents typical navigation solutions, considers each solution’s appropriateness for close-proximity missions, and compares performance.
7

Multi-fidelity Design and Analysis of Single Hub Multi-rotor High Pressure Centrifugal Compressor

Muppana, Sai January 2018 (has links)
No description available.
8

Multi-Rotor--Aided Three-Dimensional 802.11 Wireless Heat Mapping

Pack, Scott James 18 March 2014 (has links) (PDF)
Traditional wireless site surveys produce a heat-map of link strength or quality over a target area, usually on the ground plane. In recent years research has gone into using aerial drones in network attack and surveillance, making three dimensional awareness of wireless coverage areas of interest. A multi-rotor drone and data collection module were built and tested as part of this research. Site assessments were conducted both in open space and near structures. Collected data was interpolated across the target area, and visualized as points and contours. These visualizations were exported to a Keyhole Markup Language (KML) for visualization in context. Resulting visualizations proved to be beneficial in identifying the coverage area of both authorized and rogue access points.
9

Modeling of Ground Effect Benefits for Multi-Rotor Small Unmanned Aerial Systems at Hover

Eberhart, Gina M. January 2017 (has links)
No description available.
10

Lifting body design and CFD analysis of a novel long range pentacopter, the TILT LR drone

Cagatay, Daniel, Yuan, Haoqian January 2016 (has links)
In the thesis, a lifting body has been designed aiming to generate lift force for the pentacopter, called TILT LR (Long Range), at higher velocities during flights to improve the aerodynamic performances. The configuration, which is used as the skeleton of the long range drone for up to 75 kilometers flights, is based upon a tilting system allowing the rotors to rotate around their own axis in both pitch and roll angles. This offers the possibility to the TILT LR flying withoutany vertical excess thrust at a proper angle of attack and velocity. This new drone can be directly applied to missions require long flight time or cover long distance, such as Search & Rescue(SAR), power lines and off-shore structures inspection, fire monitoring or surveillance. Several main CAD models have been created during the process of design and presented in the report together with the final design. For each model in the process, CFD simulations have been applied to observe the behaviors of the flows around the surfaces of the body during steady flights, followed by a brief analysis for further modification. A series of simulations with varying velocities and angle of attack have been performed for the final design, analyzing its performances under different air conditions. Flight envelope of the design has been presented also, together with some ideas of possible further studies on the pentacopter.

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