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All Articles in Dynamics and Dynamical Systems

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Study Of Input Space For State Estimation Of High-Rate Dynamics, Jonathan Hong, Simon Laflamme, Jacob Dodson 2018 Iowa State University

Study Of Input Space For State Estimation Of High-Rate Dynamics, Jonathan Hong, Simon Laflamme, Jacob Dodson

Civil, Construction and Environmental Engineering Publications

High‐rate dynamic systems are defined as systems being exposed to highly dynamic environments that comprise high‐rate and high‐amplitude events. Examples of such systems include civil structures exposed to blast, space shuttles prone to debris strikes, and aerial vehicles experiencing in‐flight changes. The high‐rate dynamic characteristics of these systems provides several possibilities for state estimators to improve performance, including a high potential to reduce injuries and save lives. In this paper, opportunities and challenges that are specific to state estimation of high‐rate dynamic systems are presented and discussed. It is argued that a possible path ...


Adaptive Observers For Structural Health Monitoring Of High-Rate, Time-Varying Dynamic Systems, B. S. Joyce, J. Hong, J. C. Dodson, J. C. Wolfson, Simon Laflamme 2018 University of Dayton Research Institute

Adaptive Observers For Structural Health Monitoring Of High-Rate, Time-Varying Dynamic Systems, B. S. Joyce, J. Hong, J. C. Dodson, J. C. Wolfson, Simon Laflamme

Civil, Construction and Environmental Engineering Conference Presentations and Proceedings

Safe and reliable operation of hypersonic aircraft, space structures, advanced weapon systems, and other high-rate dynamic systems depends on advances in state estimators and damage detection algorithms. High-rate dynamic systems have rapidly changing input forces, rate-dependent and time-varying structural parameters, and uncertainties in material and structural properties. While current structural health monitoring (SHM) techniques can assess damage on the order of seconds to minutes, complex high-rate structures require SHM methods that detect, locate, and quantify damage or changes in the structure’s configuration on the microsecond timescale.

This paper discusses the importance of microsecond structural health monitoring (μSHM) and some ...


A Dynamical System Approach For Resource-Constrained Mobile Robotics, Tauhidul Alam 2018 Florida International University

A Dynamical System Approach For Resource-Constrained Mobile Robotics, Tauhidul Alam

FIU Electronic Theses and Dissertations

The revolution of autonomous vehicles has led to the development of robots with abundant sensors, actuators with many degrees of freedom, high-performance computing capabilities, and high-speed communication devices. These robots use a large volume of information from sensors to solve diverse problems. However, this usually leads to a significant modeling burden as well as excessive cost and computational requirements. Furthermore, in some scenarios, sophisticated sensors may not work precisely, the real-time processing power of a robot may be inadequate, the communication among robots may be impeded by natural or adversarial conditions, or the actuation control in a robot may be ...


Variable Input Observer For State Estimation Of High-Rate Dynamics, Jonathan Hong, Liang Cao, Simon Laflamme, Jacob Dodson 2018 Iowa State University

Variable Input Observer For State Estimation Of High-Rate Dynamics, Jonathan Hong, Liang Cao, Simon Laflamme, Jacob Dodson

Simon Laflamme

High-rate systems operating in the 10 μs to 10 ms timescale are likely to experience damaging effects due to rapid environmental changes (e.g., turbulence, ballistic impact). Some of these systems could benefit from real-time state estimation to enable their full potential. Examples of such systems include blast mitigation strategies, automotive airbag technologies, and hypersonic vehicles. Particular challenges in high-rate state estimation include: 1) complex time varying nonlinearities of system (e.g. noise, uncertainty, and disturbance); 2) rapid environmental changes; 3) requirement of high convergence rate. Here, we propose using a Variable Input Observer (VIO) concept to vary the input ...


Robust Variable Input Observer For Structural Health Monitoring Of Systems Experiencing Harsh Extreme Environments, Jonathan Hong, Liang Cao, Simon Laflamme, Jacob Dodson 2018 Iowa State University

Robust Variable Input Observer For Structural Health Monitoring Of Systems Experiencing Harsh Extreme Environments, Jonathan Hong, Liang Cao, Simon Laflamme, Jacob Dodson

Simon Laflamme

Systems experiencing events in the order of 10μs-10ms timescales, for instance highrate dynamics or harsh extreme environments, may encounter rapid damaging effects. If the structural health of such systems could be accurately estimated in a timely manner, preventative measures could be employed to minimize adverse effects. Previously, a Variable Input Observer (VIO) coupled with a neuro-observer was proposed by the authors as a potential solution in monitoring their structural health. The objective of the VIO is to provide state estimation based on an optimal input space allowed to vary as a function of time. The VIO incorporates the use of ...


Microsecond State Monitoring Of Nonlinear Time-Varying Dynamic Systems, Jacob Dodson, Bryan Joyce, Simon Laflamme, Janet Wolfson 2018 Air Force Research Laboratory

Microsecond State Monitoring Of Nonlinear Time-Varying Dynamic Systems, Jacob Dodson, Bryan Joyce, Simon Laflamme, Janet Wolfson

Simon Laflamme

Reliable operation of next generation high-speed complex structures (e.g. hypersonic air vehicles, space structures, and weapons) relies on the development of microsecond structural health monitoring (μSHM) systems. High amplitude impacts may damage or alter the structure, and therefore change the underlying system configuration and the dynamic response of these systems. While state-of-the-art structural health monitoring (SHM) systems can measure structures which change on the order of seconds to minutes, there are no real-time methods for detection and characterization of damage in the microsecond timescales.

This paper presents preliminary analysis addressing the need for microsecond detection of state and parameter ...


Adaptive Structural Control Using Dynamic Hyperspace, Simon Laflamme 2018 Iowa State University

Adaptive Structural Control Using Dynamic Hyperspace, Simon Laflamme

Simon Laflamme

The design of closed-loop structural control systems necessitates a certain level of robustness to cope with system uncertainties. Neurocontrollers, a type of adaptive control system, have been proposed to cope with those uncertainties. However, the performance of neural networks can be substantially influenced by the choice of the input space, or the hyperspace in which the representation lies. For instance, input selection may influence computation time, adaptation speed, effects of the curse of dimensionality, understanding of the representation, and model complexity. Input space selection is often overlooked in literature, and inputs are traditionally determined offline for an optimized performance of ...


High Strain Rate Dynamic Response Of Aluminum 6061 Micro Particles At Elevated Temperatures And Varying Oxide Thicknesses Of Substrate Surface, Carmine Taglienti 2018 University of Massachusetts Amherst

High Strain Rate Dynamic Response Of Aluminum 6061 Micro Particles At Elevated Temperatures And Varying Oxide Thicknesses Of Substrate Surface, Carmine Taglienti

Masters Theses

Cold spray is a unique additive manufacturing process, where a large number of ductile metal micro particles are deposited to create new surface coatings or free-standing structures. Metallic particles are accelerated through a gas stream, reaching velocities of over 1 km/s. Accelerated particles experience a high-strain-rate microscopic ballistic collisions against a target substrate. Large amounts of kinetic energy results in extreme plastic deformation of the particles and substrate. Though the cold spray process has been in use for decades, the extreme material science behind the deformation of particles has not been well understood due to experimental difficulties arising from ...


Simulation Of Gas Dynamic Cold Spray Process, Sai Rajkumar Vadla 2018 South Dakota State University

Simulation Of Gas Dynamic Cold Spray Process, Sai Rajkumar Vadla

Electronic Theses and Dissertations

The utilization of computational fluid dynamics (CFD) as a study tool in the aerodynamics and turbomachinery industry reinforces efficiency in the design of aircraft or for understanding the flow through pipes. CFD offer tools to model different geometries and perform a more extensive study of the flow phenomena. This gives the opportunity to model a variety of geometries and analyze their behavior under different operating conditions. A similar approach can be applied to coating technologies. Coating technologies play an essential role in the manufacturing industry. Their ability to form layers of specific materials onto engineering components to enhance mechanical and ...


Optimization Of Microfluidic Particle Separator Geometry Using Computational Fluid Dynamics, Joseph Petersen 2018 South Dakota State University

Optimization Of Microfluidic Particle Separator Geometry Using Computational Fluid Dynamics, Joseph Petersen

Electronic Theses and Dissertations

Computational fluid dynamics software was used to simulate the motion of circulating tumor cells in a variety of microfluidic cell isolation devices. Design of several novel microfluidic cell isolation devices was aided by viewing streamlines of fluid in devices in simulation. Devices that performed best in simulation used 5-micrometer wide guiding channels to guide cells to the capture location in the device. While these devices performed better than other devices in simulation and captured all particles regardless of position along inlet, experimental results differ from simulation.


Thermodynamics Of Coherent Structures Near Phase Transitions, Julia M. Meyer, Ivan Christov 2017 Purdue University

Thermodynamics Of Coherent Structures Near Phase Transitions, Julia M. Meyer, Ivan Christov

The Summer Undergraduate Research Fellowship (SURF) Symposium

Phase transitions within large-scale systems may be modeled by nonlinear stochastic partial differential equations in which system dynamics are captured by appropriate potentials. Coherent structures in these systems evolve randomly through time; thus, statistical behavior of these fields is of greater interest than particular system realizations. The ability to simulate and predict phase transition behavior has many applications, from material behaviors (e.g., crystallographic phase transformations and coherent movement of granular materials) to traffic congestion. Past research focused on deriving solutions to the system probability density function (PDF), which is the ground-state wave function squared. Until recently, the extent to ...


Development Of The End-Effector Of A Cable-Driven Parallel Manipulator For Automated Crop Sensing, Iman Salafian 2017 University of Nebraska - Lincoln

Development Of The End-Effector Of A Cable-Driven Parallel Manipulator For Automated Crop Sensing, Iman Salafian

Mechanical (and Materials) Engineering -- Dissertations, Theses, and Student Research

A four cable-driven parallel manipulator (4CDPM), consisting of sophisticated spectrometers and imagers, is under development for use in acquiring phenotypic and environmental data over an acre-sized maize field. This thesis presents the design, controls, and testing of two sub-systems in a 4CDPM: a Center of Mass Balance System (CMBS) and a Drop-Down System (DDS).

One of the factors that influences stability is the center of mass (COM) position of the end effector. An offset in COM can cause a pendulum effect or an undesired tilt angle. A center of mass balancing system is presented in this thesis to minimize the ...


Angle Of Attack Determination Using Inertial Navigation System Data From Flight Tests, Jack Kevin Ly 2017 University of Tennessee, Knoxville

Angle Of Attack Determination Using Inertial Navigation System Data From Flight Tests, Jack Kevin Ly

Masters Theses

Engineers and pilots rely on mechanical flow angle vanes on air data probes to determine the angle of attack of the aircraft in flight. These probes, however, are costly, come with inherent measurement errors, affect the flight characteristics of the aircraft, and are potentially dangerous in envelope expansion flights. Advances in the accuracy, usability, and affordability of inertial navigation systems allow for angle of attack to be determined accurately without direct measurement of the airflow around the aircraft. Utilizing an algorithm developed from aircraft equations of motion, a post-flight data review is completed as the first step in proving the ...


Variable Input Observer For State Estimation Of High-Rate Dynamics, Jonathan Hong, Liang Cao, Simon Laflamme, Jacob Dodson 2017 Iowa State University

Variable Input Observer For State Estimation Of High-Rate Dynamics, Jonathan Hong, Liang Cao, Simon Laflamme, Jacob Dodson

Civil, Construction and Environmental Engineering Conference Presentations and Proceedings

High-rate systems operating in the 10 μs to 10 ms timescale are likely to experience damaging effects due to rapid environmental changes (e.g., turbulence, ballistic impact). Some of these systems could benefit from real-time state estimation to enable their full potential. Examples of such systems include blast mitigation strategies, automotive airbag technologies, and hypersonic vehicles. Particular challenges in high-rate state estimation include: 1) complex time varying nonlinearities of system (e.g. noise, uncertainty, and disturbance); 2) rapid environmental changes; 3) requirement of high convergence rate. Here, we propose using a Variable Input Observer (VIO) concept to vary the ...


C.V. - Wojciech Budzianowski, Wojciech M. Budzianowski 2017 Wojciech Budzianowski Consulting Services

C.V. - Wojciech Budzianowski, Wojciech M. Budzianowski

Wojciech Budzianowski

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Renewable Energy And Sustainable Development (Resd) Group, Wojciech M. Budzianowski 2017 Wroclaw University of Technology

Renewable Energy And Sustainable Development (Resd) Group, Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.


Robust Variable Input Observer For Structural Health Monitoring Of Systems Experiencing Harsh Extreme Environments, Jonathan Hong, Liang Cao, Simon Laflamme, Jacob Dodson 2017 Iowa State University

Robust Variable Input Observer For Structural Health Monitoring Of Systems Experiencing Harsh Extreme Environments, Jonathan Hong, Liang Cao, Simon Laflamme, Jacob Dodson

Civil, Construction and Environmental Engineering Conference Presentations and Proceedings

Systems experiencing events in the order of 10μs-10ms timescales, for instance highrate dynamics or harsh extreme environments, may encounter rapid damaging effects. If the structural health of such systems could be accurately estimated in a timely manner, preventative measures could be employed to minimize adverse effects. Previously, a Variable Input Observer (VIO) coupled with a neuro-observer was proposed by the authors as a potential solution in monitoring their structural health. The objective of the VIO is to provide state estimation based on an optimal input space allowed to vary as a function of time. The VIO incorporates the use of ...


Built-In Bicycle Rack For Cars, Scott A. Hansberry 2017 Central Washington University

Built-In Bicycle Rack For Cars, Scott A. Hansberry

All Undergraduate Projects

Transporting a bicycle after riding somewhere and then needing to be pickup can be problematic. Bicycles will not fit in most vehicles without removing components. There is also the risk of damaging the inside of the vehicle. Expecting everyone to have a bike rack for their vehicle is unrealistic because the bike rack could be considered unappealing visually, take up to much space in the trunk, or limit the vehicle owner’s access to the trunk. The solution to this problem is a bike rack that mounts onto your car and then mounts your bike onto the rack. Most people ...


Asme Baja Rc Car Drivetrain, Walter Lackey 2017 Central Washington University

Asme Baja Rc Car Drivetrain, Walter Lackey

All Undergraduate Projects

The ASME Baja car is a student built radio controlled car, which will compete with other schools in a variety races. The drivetrain aspect of the car must smoothly transfer power from the motor to the rear wheels of the car. The drivetrain must be designed in collaboration with the other team member’s suspension system to avoid interference. The majority of the parts in the drivetrain are purchased parts intended for various applications. These parts were chosen based on their proximity to the optimal calculated values. Power flows from the electric motor through a single gear reduction, then through ...


Investigating The Physical Mechanisms That Impact Electric Fields In The Atmosphere, Greg M. Lucas 2017 University of Colorado at Boulder

Investigating The Physical Mechanisms That Impact Electric Fields In The Atmosphere, Greg M. Lucas

Aerospace Engineering Sciences Graduate Theses & Dissertations

The underlying physics and dynamics of the atmosphere drive electric currents and establish electric fields in a phenomenon known as the global electric circuit (GEC). The GEC has been observed and modeled with limiting assumptions and parameterizations in previous research. This thesis describes the incorporation of a physics-based GEC modeling scheme into a sophisticated climate model to describe the evolution of GEC currents, ground-ionosphere potential, electric fields, and conductivity within the atmosphere. Supporting measurements of atmospheric electric fields over time were used to describe the impact of local meteorological changes and assess the GEC contribution to near-surface electric fields.

The ...


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