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Full-Text Articles in Engineering
Preliminary Modeling, Control, And Trajectory Design For Miniature Autonomous Tailsitters, Nathan B. Knoebel, Stephen R. Osborne, Deryl Snyder, Timothy W. Mclain, Randal W. Beard, Andrew Mark Eldredge
Preliminary Modeling, Control, And Trajectory Design For Miniature Autonomous Tailsitters, Nathan B. Knoebel, Stephen R. Osborne, Deryl Snyder, Timothy W. Mclain, Randal W. Beard, Andrew Mark Eldredge
Faculty Publications
A tailsitter UAV has unique advantages over typical fixed wing aircraft or hovercraft. This paper highlights topics of interest in our preliminary research in developing a tailsitter UAV. An aerodynamic model and quaternion-based attitude and position control scheme is presented for controlling a tailsitter through hover maneuvers, with simulation results. Desired trajectories are also developed through feedback linearization of the dynamic equations, intended for quaternion-based attitude control. Finally, a hardware platform is proposed.
Predicting Tem Cell Measurements From Near Field Scan Data, Haixiao Weng, Daryl G. Beetner, Richard E. Dubroff
Predicting Tem Cell Measurements From Near Field Scan Data, Haixiao Weng, Daryl G. Beetner, Richard E. Dubroff
Electrical and Computer Engineering Faculty Research & Creative Works
A procedure is proposed for predicting TEM cell measurements from near field scans by modeling near-field scan data using equivalent sources. The first step in this procedure is to measure the tangential electric and magnetic fields over the circuit. Electric and magnetic fields are estimated from probe measurements by compensating for the characteristics of the probe. An equivalent magnetic and electric current model representing emissions is then generated from the compensated fields. These equivalent sources are used as an impressed source in an analytical formula or full wave simulation to predict measurements within the TEM cell. Experimental verification of the …
Simulation And Modeling Of Return Waveforms From A Ladar Beam Footprint In Usu Ladarsim, Scott E. Budge, B.C. Leishman, R.T. Pack
Simulation And Modeling Of Return Waveforms From A Ladar Beam Footprint In Usu Ladarsim, Scott E. Budge, B.C. Leishman, R.T. Pack
Electrical and Computer Engineering Faculty Publications
Ladar systems are an emerging technology with applications in many fields. Consequently, simulations for these systems have become a valuable tool in the improvement of existing systems and the development of new ones. This paper discusses the theory and issues involved in reliably modeling the return waveform of a ladar beam footprint in the Utah State University LadarSIM simulation software. Emphasis is placed on modeling system-level effects that allow an investigation of engineering tradeoffs in preliminary designs, and validation of behaviors in fabricated designs. Efforts have been made to decrease the necessary computation time while still maintaining a usable model. …
Characterization Of Transmission Lines At Ir, Tasneem A. Mandviwala, José Manuel López-Alonso, Brian A. Lail, Glenn D. Boreman
Characterization Of Transmission Lines At Ir, Tasneem A. Mandviwala, José Manuel López-Alonso, Brian A. Lail, Glenn D. Boreman
Electrical Engineering and Computer Science Faculty Publications
We demonstrate the first long wave infrared (LWIR) transmission line design and characterization. Two of the widely used transmission-lines: coplanar striplines (CPS) and microstrip (MS) lines are characterized at IR frequency (28.3THz), in terms of transmission line parameters: characteristic impedance (Z₀, attenuation constant (α) and effective index of refraction (nᵉᶠᶠ), through modeling, fabrication and measurement. These transmission-line parameters cannot be directly measured, what can be measured is the antenna response. So we compute, measure and compare the response of the dipole antenna connected to these transmission lines as a function of transmission-line length. The response depends on the transformation of …
Circuit Models For Power Bus Structures On Printed Circuit Boards Using A Hybrid Fem-Spice Method, Todd H. Hubing, Chunlei Guo
Circuit Models For Power Bus Structures On Printed Circuit Boards Using A Hybrid Fem-Spice Method, Todd H. Hubing, Chunlei Guo
Electrical and Computer Engineering Faculty Research & Creative Works
Power bus structures consisting of two parallel conducting planes are widely used on high-speed printed circuit boards. In this paper, a full-wave finite-element method (FEM) method is used to analyze power bus structures, and the resulting matrix equations are converted to equivalent circuits that can be analyzed using SPICE programs. Using this method of combining FEM and SPICE, power bus structures of arbitrary shape can be modeled efficiently both in the time-domain and frequency-domain, along with the circuit components connected to the bus. Dielectric loss and losses due to the finite resistance of the power planes can also be modeled. …
Simulation Model For Assessing Transient Performance Of Capacitive Voltage Transformers, I. Sule, Ganesh K. Venayagamoorthy, U. O. Aliyu
Simulation Model For Assessing Transient Performance Of Capacitive Voltage Transformers, I. Sule, Ganesh K. Venayagamoorthy, U. O. Aliyu
Electrical and Computer Engineering Faculty Research & Creative Works
In determining the correct operation of relays of a protection scheme, proper representation of instrument transformers and their behavior in conditions where there can be transient is very critical. This paper presents a simulation model for assessing the transient performance of capacitive voltage transformers (CVTs). In order to test the validity of the developed model, four CVT operational conditions are considered using field data collected from one of the Nigerian electric utility 330/132/33 kV substations. The model simulation results revealed various configuration performance responses that could affect relay protection schemes to different degrees. As expected, the CVT responses showed that …
Techniques In The Design Of Thermomechanical Microactuators, Larry L. Howell, Timothy W. Mclain, Michael S. Baker, Christian D. Lott
Techniques In The Design Of Thermomechanical Microactuators, Larry L. Howell, Timothy W. Mclain, Michael S. Baker, Christian D. Lott
Faculty Publications
The purpose of this chapter is to provide fundamental background for the design of thermomechanical microactuators. Actuation has been a particularly challenging aspect of microsystem development. Many actuation approaches used at the macro level, such as hydraulics, pneumatics, electric motors, internal combustion engines and turbines, are either too difficult to fabricate at the micro level or do not work well at that scale. Electrostatic attraction is one approach that has been widely used for actuation of microsystems; however, electrostatic actuators tend to have high voltage requirements and low output force capabilities. While electrostatic actuation is suitable for many applications, some …
General Methodology For Analysis And Modeling Of Trust Relationships In Distributed Computing, Weiliang Zhao, Vijay Varadharajan, George Bryan
General Methodology For Analysis And Modeling Of Trust Relationships In Distributed Computing, Weiliang Zhao, Vijay Varadharajan, George Bryan
Faculty of Engineering - Papers (Archive)
In this paper, we discuss a general methodology for analysis and modeling of trust relationships in distributed computing. We discuss the classification of trust relationships, categorize trust relationships into two layers and provide a hierarchy of trust relationships based on a formal definition of trust relationship. We provide guidelines for the analysis and modeling of trust relationships. We review operations on trust relationships and relative types of trust relationships in our previous work. We provide a set of definitions for the properties of direction and symmetry of trust relationships. In order to analyze and model the scope and diversity of …
Kinetics Of The Peritectic Phase Transformation: In-Situ Measurements And Phase Field Modeling, Dominic J. Phelan, Mark H. Reid, Rian J. Dippenaar
Kinetics Of The Peritectic Phase Transformation: In-Situ Measurements And Phase Field Modeling, Dominic J. Phelan, Mark H. Reid, Rian J. Dippenaar
Faculty of Engineering - Papers (Archive)
An experimental study has been conducted into the role of cooling rate on the kinetics of the peritectic phase transformation in a Fe-C alloy. The interfacial growth velocities of the peritectic phase transformation were measured in situ for cooling rates of 100, 50, and 10 K/min. In-situ observations were obtained using high-temperature laser scanning confocal microscopy (HTLSCM) in a concentric solidification configuration. The experimentally measured interface velocities of the liquid/austenite (L/γ) and austenite/delta-ferrite (γ/δ) interphase boundaries were observed to increase with higher cooling rates. A unique finding of this study was that as the cooling rate increased, there was a …