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 19 of 19 for “"parafoil"”.
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Robust planning for autonomous parafoil
Parafoil trajectory planning systems must be able to accurately guide the highly non-linear, under-actuated parafoil system from the drop zone to the pre-determined impact point. Parafoil planning systems are required to navigate highly complex terrain scenarios, particularly in the presence of an …
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Coupled Fluid-Structure Interaction Modeling of a Parafoil
… porous fabric for design optimization of a parafoil parachute’s transient performance. Canopy deformations of a single-cell square parafoil using a fluid-structure interaction (FSI) model with nonlinear material modeling is compared to an experimental setup of matching geometry. The results …
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Development of a small parafoil vehicle for precision delivery
… One of the proposed methods is a guided parafoil vehicle that is deployed from a UAV. After unfurling its canopy, it is envisioned that the vehicle would follow a planned trajectory to the target, and vision-based targeting system would be employed to provide the necessary accuracy. A …
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Inferring parafoil glide slope by extending unsettled trajectories via simulation
… at the University of Cape Town for launching parafoils from a hilltop or into a quarry. The initial objective to determine optimum glide slope of a parafoil using Design of Experiments via flight testing presented challenges. The flight tests and supporting simulations were carefully planned, …
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The development, optimisation and testing of an unmanned parafoil launch system
Parafoils have been used in various aerospace, military and sport applications to return both personnel and payloads safely to the ground. Deflection of the trailing edge flaps by means of control lines allows for turn rates of up to 60° per second, which provides superior controllability when …
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Model predictive control with application to real-time hardware and guided parafoil
… a nonlinear model and is applied to a guided parafoil to identify the advantage of using a Doppler wind sensor. A method for reducing the computational load is also introduced that is applicable to both controllers.
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Sampling-based path planner for guided airdrop in urban environments
… across the globe. A challenge for modern guided parafoil systems is to land accurately in complex terrain, including canyons and cities. This thesis presents the Rewire-RRT algorithm for parafoil terminal guidance. The algorithm uses Rapidly-Exploring Random Trees (RRT) to efficiently search for …
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Analytic chance constraints for the robust guidance of autonomous parafoils
Autonomously guided parafoil systems can deliver supplies and aid to remote, geographically diverse locations, while providing important safety and logistical advantages over ground-based transportation methods. A key challenge facing modern airborne delivery systems, such as parafoils, is the …
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Applied fast maneuvering using a hybrid controller
… was then adapted and applied to an unpowered parafoil in simulation. The parafoil hybrid controller was also implemented on a DSP chip and used in a real-time DSP-processor-based simulation of the system. This demonstrated the ability to apply the hybrid controller logic to a variety of …
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Simulation and control design of a gliding autogyro for precision airdrop
… greater degrees of accuracy. Ballistic and parafoil type delivery vehicles do not have the capacity to consistently deliver a payload on, for example, a particular rooftop in an urban combat situation. A gliding autogyro delivery platform has been investigated as a means of achieving greater …
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Path planning for autonomous parafoils using particle chance constrained rapidly-exploring random trees in a computationally constrained environment
… we study the use of PCC-RRT on an autonomous parafoil. Specifically, we explore the behavior of PCC-RRT in a computationally constrained environment by studying the tradeoff between the number of samples and number of particles per sample and its effect on miss distance in single-threaded …
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Design, Modeling and Testing of a Cascaded Heading Stabilization Controller for a Cruciform Parachute System
… performance and precision of complex, expensive parafoil systems. The improvements made to the platform can be summarized in two main contributions. First, through the use of a systematic controller design methodology and simulation-focused experimental plan, an effective heading stabilization …
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Extended Range Tactical Resupply Using Tailless UAV
… encompassing traditional aircraft and ram-air parafoil control approaches. Fixed-wing and multirotor unmanned aircraft-basedflight tests were conducted to evaluate the controllability and handling performance of the various configurations of both a fixed wing model and a model with collapsing …
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A parametric analysis of the start-up procedure and flight characteristics of a gliding autogyro
… rates and glide slopes similar to current parafoil based systems, but do so with greater precision. Over the past half-century most rotorcraft research has focused on helicopter design, only viewing autorotation as a means of achieving emergency landings. In contrast, this project utilized …
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The guided samara : design and development of a controllable single-bladed autorotating vehicle
… is currently performed using autonomously guided parafoil systems. These parafoils offer limited maneuverability and accuracy, and are often relatively complex systems with significant deployment uncertainty. The author has proposed, designed, and developed a novel precision airdrop system in the …
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Fault detection, isolation, and recovery for autonomous parafoils
… and recovery (FDIR) method for an autonomous parafoil system. The detection and isolation processes use residual signals generated from observers and other system models. Statistical methods are applied to evaluate these residuals and determine whether a fault has occurred, given a priori …
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Robust sampling-based motion planning for autonomous vehicles in uncertain environments
… for several motion planning domains, including parafoil terminal guidance and urban navigation, where the system is subject to challenging environmental and uncertainty characterizations. Hardware results demonstrate a mobile robot utilizing this framework to safely avoid dynamic obstacles.
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Development and Testing of a Steerable Cruciform Parachute System
… far less labor to manufacture compared to parafoil parachutes. Next some method of stabilizing that canopy during flight must be proposed. In this case, the system heading is to be stabilized via a single actuator by asymmetric deflection of the leading edge of one canopy panel. At this stage …