Digital Commons Network^™

Assuring Netlist-To-Bitstream Equivalence Using Physical Netlist Generation And Structural Comparison, Reilly Mckendrick, Jeffrey Goeders, Keenan Faulkner

Faculty Publications

Hardware netlists are generally converted into a bitstream and loaded onto an FPGA board through vendor-provided tools. Due to the proprietary nature of these tools, it is up to the designer to trust the validity of the design’s conversion to bitstream. However, motivated attackers may alter the CAD tools’ integrity or manipulate the stored bitstream with the intent to disrupt the functionality of the design. This paper proposes a new method to prove functional equivalence between a synthesized netlist, and the produced FPGA bitstream. The novel approach is comprised of two phases: first, we show how we can utilize implementation …

Iprec And Isoblaze: Fuzzy Subcircuit Isomorphism For Ip Detection In Physical Netlists, Dallin Dahl, Corey Simpson, Keenan Faulkner, Brent Nelson, Jeffrey Goeders

Student Works

Netlist reverse engineering has many uses, from detecting hardware trojans to recovering missing design source files. However, the basic problem of finding IP in a netlist has not been widely discussed. The problem boils down to subgraph isomorphism on graphs constructed from netlists. We present two approaches to identifying IP in larger circuits. IPRec focuses on exploiting hierarchy in the IP design and is a rather conservative approach, while Isoblaze focuses on local properties and connectivity and is more liberal in matching.

Trumpet Directivity From A Rotating Semicircular Array, Samuel D. Bellows, Joseph E. Avila, Timothy W. Leishman

Directivity

The directivity function of a played musical instrument describes the angular dependence of its acoustic radiation and diffraction about the instrument, musician, and musician’s chair. Directivity influences sound in rehearsal, performance, and recording environments and signals in audio systems. Because high-resolution, spherically comprehensive measurements of played musical instruments have been unavailable in the past, the authors have undertaken research to produce and share such data for studies of musical instruments, simulations of acoustical environments, optimizations of microphone placements, and other applications. The authors acquired the data from repeated chromatic scales produced by a trumpet played at mezzo-forte in an anechoic …

Gamelan Gong Directivity Dataset, Samuel D. Bellows, Dallin T. Harwood, Kent L. Gee, Micah R. Shepherd

Directivity

No abstract provided.

Leveraging Fpga Primitives To Improve Word Reconstruction During Netlist Reverse Engineering, Reilly Mckendrick, Corey Simpson, Brent Nelson, Jeffrey Goeders

Faculty Publications

While attempting to perform hardware trojan detection, or other low-level design analyses, it is often necessary to inspect and understand the gate-level netlist of an implemented hardware design. Unfortunately this process is challenging, as at the physical level, the design does not contain any hierarchy, net names, or word groupings. Previous work has shown how gate-level netlists can be analyzed to restore high-level circuit structures, including reconstructing multi-bit signals, which aids a user in understanding the behavior of the design. In this work we explore improvements to the word reconstruction process, specific to FPGA platforms. We demonstrate how hard-block primitives …

Precision Maritime Localization And Landing With Real-Time Kinematic Gnss, Alexander Jordan, Matthew Kent Rydalch, Tim Mclain, Michael Williamson Tabango

Student Works

This paper presents a highly effective method for UAV precision shipboard localization and landing using Real-time Kinematic Global Navigation Satellite System (RTK GNSS). To assess the feasibility of RTK GNSS for this use case we explicitly exclude vision-based localization techniques which are most often presented in the literature. Instead, the methods presented in this paper use only RTK GNSS with an inertial measurement unit aboard the landing pad to estimate the state of the boat and the relative position of the UAV with respect to the boat. We use a continuous-discrete extended Kalman filter combined with a complementary filter for …

Kemar Hats Head Orientation Directivity, Samuel D. Bellows, Timothy W. Leishman

Directivity

This directivity data set for a KEMAR head head-and-torso simulator (HATS) includes head orientations in 14 directions in 5° steps starting from 0° to 40° and then in 10° steps from 40° to 90°. The full spherical measurements followed at an a = 0.97 m radius with the mouth aperture at the spherical center. The sampling density and distribution followed the AES 5° dual-equiangular sampling standard, omitting the south pole (θ = 180°). Thus, each spherical directivity assessment included 36 polar-angle θ samples and 72 azimuthal-angle ϕ samples. The presented data include 22 1/3-octave bands, ranging from 80 Hz …

Nonlinear Trajectory Tracking Control For Winged Evtol Uavs, Jacob Willis, Randal W. Beard

Faculty Publications

Current control methods for winged eVTOL UAVs consider the vehicle primarily as a fixed-wing aircraft with the addition of vertical thrust used only during takeoff and landing. These methods provide good long-range flight handling but fail to consider the full dynamics of the vehicle for tracking complex trajectories. We present a trajectory tracking controller for the full dynamics of a winged eVTOL UAV in hover, fixed-wing, and partially transitioned flight scenarios. We show that in low- to moderate-speed flight, trajectory tracking can be achieved using a variety of pitch angles. In these conditions, the pitch of the vehicle is a …

Pitch And Thrust Allocation For Full-Flight-Regime Control Of Winged Evtol Uavs, Jacob B. Willis, Randal W. Beard

Faculty Publications

Trajectory tracking control for winged eVTOL aircraft is complicated by the high-angle-of-attack aerodynamics experienced during navigational flight occurring immediately after takeoff and immediately before landing. The total energy use of the vehicle can be reduced and the control performance can be improved by appropriately considering the pitch angle of the vehicle in varying flight conditions. We present a review of high-angle-of-attack aerodynamic models as well as an algorithm for finding the optimal pitch and thrust of a winged eVTOL throughout its flight regime. We show simulation results demonstrating a 75% reduction in tracking error over our previous work while maintaining …

Average Speech Directivity, Samuel D. Bellows, Claire M. Pincock, Jennifer K. Whiting, Timothy W. Leishman

Directivity

Speech directivity describes the angular dependence of acoustic radiation from a talker’s mouth and nostrils and diffraction about his or her body and chair (if seated). It is an essential physical aspect of communication affecting sounds and signals in acoustical environments, audio, and telecommunication systems. Because high-resolution, spherically comprehensive measurements of live, phonetically balanced speech have been unavailable in the past, the authors have undertaken research to produce and share such data for simulations of acoustical environments, optimizations of microphone placements, speech studies, and other applications. The measurements included three male and three female talkers who repeated phonetically balanced passages …

The Homography As A State Transformation Between Frames In Visual Multi-Target Tracking, Jacob H. White, Randal W. Beard

Student Works

No abstract provided.

An Iterative Five-Point Algorithm With Application To Multi-Target Tracking, Jacob H. White, Randal W. Beard

Student Works

We present ReSORtSAC: Recursively-seeded optimization, refinement, sample, and consensus. ReSORtSAC is a novel algorithm that can be used to estimate the relative pose between consecutive frames of a video sequence. Relative pose estimation algorithms typically generate a large number of hypotheses from minimum subsets and score them in order to be robust to noise and outliers. The relative pose is often represented using the essential matrix. Previous methods calculate essential matrix hypotheses directly without utilizing prior information. These equations are complex to evaluate and can return up to ten essential matrix solutions for each minimum subset, all of which must …

Relative Navigation: A Keyframe-Based Approach For Observable Gps-Degraded Navigation, David O. Wheeler, Daniel P. Koch, James S. Jackson, Timothy W. Mclain, Randal W. Beard

Faculty Publications

State estimation for micro air vehicles (MAVs) often depends heavily on reliable global measurements such as GPS. When global measurements are unavailable, additional sensors, such as cameras or laser scanners, are commonly used to provide measurements of the MAV’s translation and rotation relative to a previously observed keyframe image or scan. With the use of only relative sensors, however, the global position and heading of the vehicle are unobservable and cannot be reliably reconstructed. Many existing approaches work with respect to a global reference frame, resulting in a loss of state observability. This article highlights that unobservability leads to inconsistency …

3d Printed High Density, Reversible, Chip-To-Chip Microfluidic Interconnects, Hua Gong, Adam T. Woolley, Gregory P. Nordin

Faculty Publications

Our latest developments in miniaturizing 3D printed microfluidics [Gong et al., Lab Chip, 2016, 16, 2450; Gong et al., Lab Chip, 2017, 17, 2899] offer the opportunity to fabricate highly integrated chips that measure only a few mm on a side. For such small chips, an interconnection method is needed to provide the necessary world-to-chip reagent and pneumatic connections. In this paper, we introduce simple integrated microgaskets (SIMs) and controlled-compression integrated microgaskets (CCIMs) to connect a small device chip to a larger interface chip that implements world-to-chip connections. SIMs or CCIMs are directly 3D printed as part of the device …

Extending Motion Detection To Track Stopped Objects In Visual Multi-Target Tracking, Jacob H. White, Karl T. Salva, Randal W. Beard

Student Works

Various solutions to visual multi-target tracking have been proposed, but many of them are not capable of running in real time from a moving camera on an unmanned aerial vehicle (UAV). We present a tracker that runs in real time and tracks multiple objects while accounting for camera motion on a UAV. Our algorithm is capable of processing over 10 frames per second on a 1280x720 video sequence.

We utilize Recursive-RANSAC, an efficient algorithm for tracking multiple objects in clutter. Our work combines motion detection with optical flow and feature matching to allow stationary objects to be tracked. We use …

Visual Multiple Target Tracking From A Descending Aerial Platform, Parker C. Lusk, Randal Beard

Student Works

A real-time visual multiple target tracker is demonstrated onboard a descending multirotor. Measurements of moving ground targets are generated using the Kanade-Lucas-Tomasi (KLT) tracking method. Homography-based image registration is used to align the measurements into the same coordinate frame, allowing for the detection of independently moving objects. The recently developed Recursive-RANSAC algorithm uses the visual measurements to estimate targets in clutter. Altitude-dependent tuning increases track continuity and coverage during the descent of the vehicle. The algorithm requires no operator interaction and increases the situation awareness of the unmanned aerial system. Real-time tracking efficiency is analyzed on GPUs and CPUs. Tracking …

Relative Target Estimation Using A Cascade Of Extended Kalman Filters, Jerel Nielsen, Randal Beard

Student Works

This paper presents a method of tracking multiple ground targets from an unmanned aerial vehicle (UAV) in a 3D reference frame. The tracking method uses a monocular camera and makes no assumptions on the shape of the terrain or the target motion. The UAV runs two cascaded estimators. The first is an Extended Kalman Filter (EKF), which is responsible for tracking the UAV’s state, such as position and velocity relative to a fixed frame. The second estimator is an EKF that is responsible for estimating a fixed number of landmarks within the camera’s field of view. Landmarks are parameterized by …

Relative Navigation Of Autonomous Gps-Degraded Micro Air Vehicles, David O. Wheeler, Daniel P. Koch, James S. Jackson, Gary J. Ellingson, Paul W. Nyholm, Timothy W. Mclain, Randal W. Beard

Faculty Publications

Many current approaches for navigation of micro air vehicles (MAVs) in GPS-degraded environments use a globally-referenced state for estimation and control, even though this state is not observable when GPS is unavailable. By working with respect to a local reference frame, the relative navigation (RN) framework presented in this paper ensures that the state maintains observability and that the uncertainty remains bounded, consistent, and normally-distributed. RN further insulates flight-critical estimation and control processes from the large global updates common in GPS-degraded MAV flight. This paper provides a thorough description of the details needed to successfully implement the RN framework on …

Quantum Dot Band Gap Investigations, John Ryan Peterson

Student Works

Improving solar panel efficiency has become increasingly important as the world searches for cheap renewable energy. Recent developments in the industry have focused on multi-layer cells, some of which use semiconducting dyes to absorb light in place of crystalline solids. In this paper, I characterize various dyes recently synthesized for use in solar panels. These dyes contain semiconducting nanoparticles enclosed primarily by the protein ferritin to limit particle size. The band gaps were measured using either optical absorption spectroscopy or measuring the photoluminescence spectrum, depending on the type of semiconductor. The results indicate that both manganese oxide and lead sulfide …

Modeling And Control Of A Tailsitter With A Ducted Fan, Matthew Elliott Argyle

Student Works

There are two traditional aircraft categories: fixed-wing which have a long endurance and a high cruise airspeed and rotorcraft which can take-off and land vertically. The tailsitter is a type of aircraft that has the strengths of both platforms, with no additional mechanical complexity, because it takes off and lands vertically on its tail and can transition the entire aircraft horizontally into high-speed flight. In this dissertation, we develop the entire control system for a tailsitter with a ducted fan. The standard method to compute the quaternion-based attitude error does not generate ideal trajectories for a hovering tailsitter for some …

Jezik: A Cognitive Translation System Employing A Single, Visible Spectrum Tracking Detector, Davor Bzik

Student Works

A link between eye movement mechanics and the mental processing associated with text reading has been established in the past. The pausing of an eye gaze on a specific word within a sentence reflects correctness or fluency of a translated text. A cognitive translation system has been built employing a single, inexpensive web camera without the use of infrared illumination. It was shown that the system translates the text, detects rarely occurring and out-of-context words from eye gaze information, and provides solutions in real time while the user is still reading. The solutions are in form of a translation, definition …

High Density 3d Printed Microfluidic Valves, Pumps, And Multiplexers, Hua Gong, Adam T. Woolley, Gregory P. Nordin

Faculty Publications

In this paper we demonstrate that 3D printing with a Digital Light Processor stereolithographic (DLP-SLA) 3D printer can be used to create high density microfluidic devices with active components such as valves and pumps. Leveraging our previous work on optical formulation of inexpensive resins (RSC Adv. 5, 106621, 2015), we demonstrate valves with only 10% of the volume of our original 3D printed valves (Biomicrofluidics 9, 016501, 2015), which were already the smallest that have been reported. Moreover, we show that inclusion of a thermal initiator in the resin formulation along with a post-print bake can dramatically improve the durability …

Optical Approach To Resin Formulation For 3d Printed Microfluidics, Hua Gong, Michael Beauchamp, Steven Perry, Adam T. Woolley, Gregory P. Nordin

Faculty Publications

Microfluidics imposes different requirements on 3D printing compared to many applications because the critical features for microfluidics consist of internal microvoids. Resins for general 3D printing applications, however, are not necessarily formulated to meet the requirements of microfluidics and minimize the size of fabricated voids. In this paper we use an optical approach to guide custom formulation of resins to minimize the cross sectional size of fabricated flow channels as exemplars of such voids. We focus on stereolithgraphy (SL) 3D printing with Digital Light Processing (DLP) based on a micromirror array and use a commercially available 3D printer. We develop …

Phase 1 Final Report: Preamble Assisted Equalization For Aeronautical Telemetry (Paq), Michael Rice, Mohammad Saquib, Arlene Cole-Rhodes, Farzad Moazzami, Erik Perrins

Faculty Publications

This is the Phase 1 report for Preamble Assisted Equalization for Aeronautical Telemetry (PAQ).

Executive Summary:

To fully leverage the benefits of a periodically inserted preamble, the preamble is used to estimate the state of the channel. To this end the following algorithms have been developed, tested in simulation, and ported to the GPU-based real-time system:

1. The preamble detector, which scans the received samples searching for the presence of the preamble. The location of the preamble in the received samples is required to use the received samples to estimate the frequency offset, channel impulse response, and noise variance. The …

Microfluidic Valves Made From Polymerized Polyethylene Glycol Diacrylate, Gregory P. Nordin

Faculty Publications

Pneumatically actuated, non-elastomeric membrane valves fabricated from polymerized polyethylene glycol diacrylate (poly-PEGDA) have been characterized for temporal response, valve closure, and long-term durability. A ∼100 ms valve opening time and a ∼20 ms closure time offer valve operation as fast as 8 Hz with potential for further improvement. Comparison of circular and rectangular valve geometries indicates that the surface area for membrane interaction in the valve region is important for valve performance. After initial fabrication, the fluid pressure required to open a closed circular valve is ∼50 kPa higher than the control pressure holding the valve closed. However, after ∼1000 …

Analysis Of An Improved Imu-Based Observer For Multirotor Helicopters, John Charles Macdonald, Robert C. Leishman, Randal W. Beard, Timothy W. Mclain

Faculty Publications

Multirotor helicopters are increasingly popular platforms in the robotics community. Making them fully autonomous requires accurate state estimation. We review an improved dynamic model for multirotor helicopters and analyze the observability properties of an estimator based on this model. The model allows better use of IMU data to facilitate accurate state estimates even when updates from a sensor measuring position become less frequent and less accurate. We demonstrate that the position update rate can be cut in half versus typical approaches while maintaining the same accuracy. We also find that velocity estimates are at least twice as accurate no matter …

Final Report: Multipath Modeling And Mitigation Using Multiple Antennas (M4a), Michael Rice

Faculty Publications

This report documents the effort under contract W900KK-09-C-0016. The contract comprised four phases spanning 15 April 2009 to 1 December 2012. The relationship between the effort associated with each phase and the contents of this report are as follows: Phase 1 was devoted exclusively to the channel sounding experiments with the UH-1H helicopter. The experimental setup, procedure, and results for the channel sounding experiments at Cairns Army Airfield and Patuxent River are described in Chapter 2. Good, usable data at upper L-band was captured during the Cairns Army Airfield experiments. Phase 2 was devoted to the channel sounding experiments with …

Technical Note On Manipulating Multivariate Gaussian Distributions, John C. Macdonald

Student Works

In this technical note we present some derivations treating conditional, marginal, and joint distributions for Gaussian random vectors.

Bonding Of Polydimethylsiloxane Microfluidics To Silicon-Based Sensors, Long-Fang Tsai, William C. Dahlquist, Seunghyun Kim, Gregory P. Nordin

Faculty Publications

We investigate bonding polydimethylsiloxane (PDMS) to silicon using a thin (~2μm) intermediate adhesive layer stamped onto a PDMS piece prior to bonding. In particular, we compare as adhesive layers Sylgard 184 and 182 curing agents and a UV curable adhesive (NOA 75). We examine the effect of both curing temperature and duration on curing agent bond strength. Bond strengths for the different adhesives are determined by measuring the average burst pressure at a PDMS-silicon interface using a PDMS test design. We find that Sylgard 184 curing agent gives the highest bond strength with burst pressure of 700 kPa or more …

Byu Indoor Flight System Circa June 2011, John C. Macdonald, Robert Leishman

Faculty Publications

This report documents the state of our indoor flight platform as of June 2011, the time of its first flight without a human in the loop. The report is intended to give enough detail that someone might have a reasonable hope of replicating our work from scratch.