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Articles 1 - 14 of 14

Full-Text Articles in Navigation, Guidance, Control and Dynamics

Urban Flow And Small Unmanned Aerial System Operations In The Built Environment, Kevin A. Adkins Feb 2019

Urban Flow And Small Unmanned Aerial System Operations In The Built Environment, Kevin A. Adkins

Kevin A. Adkins, PhD

The Federal Aviation Administration (FAA) has put forth a set of regulations (Part 107) that govern small unmanned aerial system (sUAS) operations. These regulations restrict unmanned aircraft (UA) from flying over people and their operation to within visual line of sight (VLOS). However, as new applications for unmanned aerial systems (UAS) are discovered, their capabilities improve, and regulations evolve, there is an increasing desire to undertake urban operations, such as urban air mobility, package delivery, infrastructure inspection, and surveillance. This built environment poses new weather hazards that include enhanced wind shear and turbulence. The smaller physical dimensions, lower mass and …

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Validation And Verification Flight Tests Of Fixed-Wing Collaborative Uass With High Speeds And High Inertias, A Ram (Bella) Kim Jun 2018

Validation And Verification Flight Tests Of Fixed-Wing Collaborative Uass With High Speeds And High Inertias, A Ram (Bella) Kim

A Ram (Bella) Kim

The research objective for this work is to validate and verify guidance, navigation, and control algorithms that are designed for fixed-wing collaborative unmanned aerial systems (UASs) in unstructured environments. A biologically-inspired swarm control theory provides a framework to distribute sensor payloads between several smaller and less complex agents that have local interactions. Controller design and flight testing of large UASs with high speeds and high inertias holding a formation in a dynamically changing environment and in the presence of external disturbances is complex and requires advanced planning and safety measures. Verification and validation flight tests were conducted using a fixed-wing …

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Control Of Multi-Agent Collaborative Fixed-Wing Uass In Unstructured Environment, A Ram (Bella) Kim Jun 2018

Control Of Multi-Agent Collaborative Fixed-Wing Uass In Unstructured Environment, A Ram (Bella) Kim

A Ram (Bella) Kim

Swarms of unmanned aircraft are the inevitable future of the aerospace industry. In recent years, swarming robots and aircraft have been a subject of much interest; however, many research projects make impractical assumptions such as point mass dynamics with no aerodynamic effects for aircraft models, and most works stop short of fully validating their methods via flight testing. This work presents a proximity based guidance, navigation, and control of multi-agent fixed-wing unmanned aerial systems in an unstructured environment. A scalable swarm navigation method is developed using adaptive moving mesh partial differential equations controlled by the free energy heat flow equation. …

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Validation And Verification Of Gnc For Large Fixed-Wing Unmanned Aerial System In Unstructured And Noisy Environment, A Ram (Bella) Kim Jun 2018

Validation And Verification Of Gnc For Large Fixed-Wing Unmanned Aerial System In Unstructured And Noisy Environment, A Ram (Bella) Kim

A Ram (Bella) Kim

The impact of high update rate on the disparity in eigenvalues of the auto-correlation matrix, along with slow convergence and reduced stability of numerical analysis are well studied. However, the impact of high update rates of autopilots on the performance of unmanned aircraft has been ignored due to the intrinsic limitations of COTS autopilots
computation power. Although MEMS based IMUs have very high update rates, the majority of existing UAS autopilot system processing power is limited to 20 Hz. In this work, the challenges and processes for developing and flight test validating an autonomous flight controller for a large 30-kg …

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Space Operations In The Suborbital Space Flight Simulator And Mission Control Center: Lessons Learned With Xcor Lynx, Pedro Llanos, Christopher Nguyen, David Williams, Kim O. Chambers Ph.D., Erik Seedhouse, Robert Davidson May 2018

Space Operations In The Suborbital Space Flight Simulator And Mission Control Center: Lessons Learned With Xcor Lynx, Pedro Llanos, Christopher Nguyen, David Williams, Kim O. Chambers Ph.D., Erik Seedhouse, Robert Davidson

Pedro J. Llanos (www.AstronauticsLlanos.com)

This study was conducted to better understand the performance of the XCOR Lynx vehicle. Because the Lynx development was halted, the best knowledge of vehicle dynamics can only be found through simulator flights. X-Plane 10 was chosen for its robust applications and accurate portrayal of dynamics on a vehicle in flight. The Suborbital Space Flight Simulator (SSFS) and Mission Control Center (MCC) were brought to the Applied Aviation Sciences department in fall 2015 at Embry-Riddle Aeronautical University, Daytona Beach campus. This academic and research tool is a department asset capable of providing multiple fields of data about suborbital simulated flights. …

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Synthetic Jet Actuator-Based Aircraft Tracking Using A Continuous Robust Nonlinear Control Strategy, N. Ramos-Pedroza, W. Mackunis, M. Reyhanoglu May 2018

Synthetic Jet Actuator-Based Aircraft Tracking Using A Continuous Robust Nonlinear Control Strategy, N. Ramos-Pedroza, W. Mackunis, M. Reyhanoglu

William MacKunis

A robust nonlinear control law that achieves trajectory tracking control for unmanned aerial vehicles (UAVs) equipped with synthetic jet actuators (SJAs) is presented in this paper. A key challenge in the control design is that the dynamic characteristics of SJAs are nonlinear and contain parametric uncertainty. The challenge resulting from the uncertain SJA actuator parameters is mitigated via innovative algebraic manipulation in the tracking error system derivation along with a robust nonlinear control law employing constant SJA parameter estimates. A key contribution of the paper is a rigorous analysis of the range of SJA actuator parameter uncertainty within which asymptotic …

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Analysis And Verification Of Cost-Effective Design Modifications To Commercially Available Fixed-Wing Unmanned Aerial Vehicle To Improve Performance, Stability And Control Characteristics, And Structural Integrity, A Ram (Bella) Kim Jan 2018

Analysis And Verification Of Cost-Effective Design Modifications To Commercially Available Fixed-Wing Unmanned Aerial Vehicle To Improve Performance, Stability And Control Characteristics, And Structural Integrity, A Ram (Bella) Kim

A Ram (Bella) Kim

In this work, several cost-effective design modifications were made to a commercially available fixed-wing unmanned aerial vehicle in order to improve overall performance and reliability. These modifications included the addition of 3D-printed winglets to improve aerodynamic performance, applying fiberglass reinforcement to areas of structural concern, the addition of rudder control surfaces for improved control authority, increasing the length of the empennage booms for both stability and control improvements, and the addition of dorsal fins to improve vertical fin stall characteristics. Design methodology and manufacturing processes were outlined, a cost breakdown was presented, and results from dynamic analysis were validated through …

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Dynamic Modeling And Simulation Of A Quadcopter With Motor Dynamics, A Ram (Bella) Kim Jan 2017

Dynamic Modeling And Simulation Of A Quadcopter With Motor Dynamics, A Ram (Bella) Kim

A Ram (Bella) Kim

Increased usage of quadcopters as an embedded system has raised the necessity of developing high quality dynamic models for designing controllers and simulations. In this work, a dynamic model was developed for a quadcopter platform by conducting experiments for estimating the moments of inertia and for determining motor dynamics. The dynamic model consisted of equations of motions derived from Newton and Euler's approach. Moments of inertia were estimated by operating a bifilar pendulum test. The motor dynamics were developed using a custom built test bed. The thrust, torque, voltage, and current were recorded in order to develop an adaptive dynamic …

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Guidance Of Multi-Agent Fixed-Wing Aircraft Using A Moving Mesh Method, A Ram (Bella) Kim Oct 2016

Guidance Of Multi-Agent Fixed-Wing Aircraft Using A Moving Mesh Method, A Ram (Bella) Kim

A Ram (Bella) Kim

This paper presents a novel guidance logic for multi-agent fixed-wing unmanned aerial systems using a moving mesh method. The moving mesh method is originally designed for use in the adaptive numerical solution of partial differential equations, where a high proportion of mesh points are placed in the regions of large solution variations and few points in the rest of the domain. In this work, the positions of the aircraft are considered as mesh nodes connected to form a triangular mesh in two spatial dimensions. The outer aircraft positions are planned with the reference point algorithm. This logic provides the outer …

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Investigation Of An Autonomous Landing Sensor For Unmanned Aerial Systems, A Ram (Bella) Kim Jan 2014

Investigation Of An Autonomous Landing Sensor For Unmanned Aerial Systems, A Ram (Bella) Kim

A Ram (Bella) Kim

This research focused on characterizing the precision, reliability, sensitivity, and uncertainty of an autonomous landing sensor. Currently, the most dangerous flight phase for autonomous aircraft is the landing and takeoff segments, accounting for almost 70% of crashes. This research analyzes the effects of the color and roughness of the landing surface, fog, ice, and varying aircraft angles on the performance of an automated landing sensor. An investigation of suitable sensors was performed and the Dimetix FLS-C30 laser altimeter was selected for testing. The standard deviation and uncertainty of each condition was found and compared. It was determined that surface color, …

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Spatial Computing In An Orbital Environment: An Exploration Of The Unique Constraints Of This Special Case To Other Spatial Computing Environments, Jeremy Straub May 2013

Spatial Computing In An Orbital Environment: An Exploration Of The Unique Constraints Of This Special Case To Other Spatial Computing Environments, Jeremy Straub

Jeremy Straub

The creation of an orbital services model (where spacecraft expose their capabilities for use by other spacecraft as part of a service-for-hire or barter system) requires effective determination of how to best transmit information between the two collaborating spacecraft. Existing approaches developed for ad hoc networking (e.g., wireless networks with users entering and departing in a pseudo-random fashion) exist; however, these fail to generate optimal solutions as they ignore a critical piece of available information. This additional piece of information is the orbital characteristics of the spacecraft. A spacecraft’s orbit is nearly deterministic if the magnitude and direction of its …

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Modeling And Control Of Space Vehicles With Fuel Slosh Dynamics, Mahmut Reyhanoglu Feb 2011

Modeling And Control Of Space Vehicles With Fuel Slosh Dynamics, Mahmut Reyhanoglu

Mahmut Reyhanoglu

"Ever since the launch of the early high-efficiency rockets, controlling liquid fuel slosh within a launch vehicle has been a major design concern. Moreover, with today's large and complex spacecraft, a substantial mass of fuel is necessary to place them into orbit and to perform orbital maneuvers."--From the book's introduction.

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Sliding Mode Control Of The Systems With Uncertain Direction Of Control Vector, Sergey V. Drakunov Dec 1992

Sliding Mode Control Of The Systems With Uncertain Direction Of Control Vector, Sergey V. Drakunov

Sergey V. Drakunov

No abstract provided.

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Sliding-Mode Observers Based On Equivalent Control Method, Sergey V. Drakunov Dec 1991

Sliding-Mode Observers Based On Equivalent Control Method, Sergey V. Drakunov

Sergey V. Drakunov

No abstract provided.

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