Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 22 for “"Multi-Rotor"”.
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Prediction & Active Control of Multi-Rotor Noise
… Reynolds number. More chiefly, they operate with multiples of rotors, which may pose some issues aerodynamically, as well as acoustically. The aim of this research is to first investigate the various noise sources in multi-rotor systems. High-fidelity simulations of two in-line counter-rotating …
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Foundations for the Coupled Inflow and Structural Dynamics of Multi-rotor Helicopters
… is expanded to calculate the coupled inflow and rotor dynamics of tandem rotor configurations. This establishes the foundation for a more complete multi-rotor, dynamic inflow model with finite-state methods. The derivation presented in this work is for the general case of two rotors in the same …
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Modeling and Control of Multi-Rotor UAVS: Design for Safety and Performance
… class of unmanned aerial vehicles (UAVs) called multi-rotors has gained significant attention. Despite remarkable progress in control and design of multirotors in the past decade, two issues, namely endurance and safety, still remain of main concerns. This thesis mainly aims at investigating …
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Assessing multi-rotor UAV controllability in low altitude fine-scale wind fields
… the sum total of torque developed by a vehicle's rotors and residual terms representing the torque required to compensate for any remaining disturbances. The metric was demonstrated on a representative small quadrotor UAV in real world and laboratory environments. Utilizing only rotor revolutions …
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Integrating supplemental lift devices to improve performance in high speed multi rotor UAVs
… and lacking control surfaces, into high-speed multi-rotor UAVs. The goal is to improve flight performance across the diverse range of mission profiles these platforms typically encounter. Multi-rotor platforms are traditionally constrained by the need for their propellers to generate both lift …
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Development of a light-weight manipulator system for an omni-directional multi-rotor platform
… manipulator attached to an omni-directional multi-rotor system known as the OmniRaptor. This prototype was developed in order to provide the OmniRaptor with the ability to precisely position a sensor in environments where wind gusts are present. In addition to its ability to complete …
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Evaluating the performance of multi-rotor UAV-Sfm imagery in assessing simple and complex forest structures: comparison to advanced remote sensing sensors
… of this study was to evaluate the performance of multirotor UAV photogrammetric point cloud in estimating homogeneous and heterogeneous forest structures, and their comparison to more accurate LiDAR data obtained from Aerial Laser Scanners (ALS), Terrestrial Laser Scanners (TLS), and more …
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Simulation and Integration of a 6-DOF Controllable Multirotor Vehicle
… 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 …
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Computer-Aided Design Software for Torsional Analysis
… 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 …
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Effect of tip-speed ratio on induced velocities near a lifting rotor
… of induced flow in the vicinity of a lifting rotor in forward flight has been conducted. The analysis is based upon an asymmetric wake which is a logical extension of that used for previous investigations. Equations for the induced velocities at an arbitrary point in space are presented in a …
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Omnidirectional obstacle detection using minimal sensing
… approach to visual obstacle detection for aerial multi-rotor vehicles (drones) is introduced. The approach achieves omnidirectional detection of obstacles via suitable synergy of hardware and software. The drone requires a specific arrangement of two cameras, opposing each other, and placed below …
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System identification for development of distributed electric propulsion vertical take-off vehicles
… procedure for estimating the inertia matrix of a multi-rotor vertical take-off and landing vehicle. The procedure starts with an overview of vehicle dynamics. An estimator and a controller are introduced based on these dynamics, which can be tuned to the desired performance specifications. Once …
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Rotorcraft Flight Dynamics and Control in Wind for Autonomous Sampling of Spatiotemporal Processes
… put into the design and use small, autonomous, multi-agent, aerial teams for a variety of military and commercial applications. In particular, small multi-rotor systems have been shown to be especially useful for carrying sensors as they have the ability to rapidly transit between locations as …
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A control architecture and human interface for agile, reconfigurable micro aerial vehicle formations
… aerial vehicles, especially for the popular multi-rotor aerial vehicle platform. Then, we discuss the dynamics of quadrotor helicopters. A quadrotor is a specific kind of multi-rotor aerial vehicle with a special property called differential flatness, which simplifies the algorithm of …
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Numerical Modeling of Synthetic Vortical Disturbance Interactions Using OpenFOAM
… of the reduced order models (ROMs) for multi-rotor unsteady aerodynamic and acoustics responses. This study employs an open-source Navier-Stokes OpenFOAM solver to model the turbulent wind flow around a building. Based on the previous studies, a momentum source generating an upstream …
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Adaptive Control Allocation for Unmanned Aerial Vehicles with Model Uncertainties
… system stability. Simulation results on a multi-rotor mathematical model are presented with effector degradation and model uncertainties (unknown center of gravity position) to show the deterioration of the command tracking performance of a classical full state feedback controller, and to …
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Urban Air Mobility (UAM) Landing Site Feasibility Analysis: A Multi-Attribute Decision Making Approach
… The analysis assumes an all-electric, advanced multi-rotor aircraft with autonomous navigational and Vertical Takeoff and Landing (VTOL) capabilities to estimate UAM landing site requirements. The thesis presents the land area requirements of UAM landing sites using Federal Aviation …
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Deep Reinforcement Learning for Multirotor Flight Control: A Comparative Study of Sim-to-Real Training and Real-World Performance
… Learning (DRL) for low-level flight control of multirotor unmanned aerial vehicles (UAVs), focusing on factors that most influence sim-to-real policy transfer. Using the Proximal Policy Optimization (PPO) algorithm, extensive ablation studies evaluated the effects of domain randomization, reward …
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Optimization of UAV-borne Aeromagnetic Surveying in Mineral Exploration
… magnetometer mounting system integrated on multi-rotor UAVs is investigated. Although a semi-rigid mount offers some technical benefits over other mounting techniques, its practical implementation allowing for the collection of industry standard aeromagnetic data has proven to be quite …
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Intelligent control and path planning for unmanned aerial vehicles
… tailored for UAVs. Firstly, the modeling of multi-rotor aerial vehicles is refined by using the Newton-Euler method, incorporating vehicle dynamics to lay the foundation for displaying the responses of UAVs in interactions with the flight environment. This is important for the emerging …
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