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Faculty Publications

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Articles 1591 - 1620 of 3295

Full-Text Articles in Engineering

High-Throughput Screening Using Fourier-Transform Infrared Imaging, Erdem Sasmaz, Kathleen Mingle, Jochen A. Lauterbach Jun 2015

High-Throughput Screening Using Fourier-Transform Infrared Imaging, Erdem Sasmaz, Kathleen Mingle, Jochen A. Lauterbach

Faculty Publications

Efficient parallel screening of combinatorial lib­ra ries is one of the most challenging aspects of the high­throughput (HT) heterogeneous catalysis workflow. Today, a number of methods have been used in HT catalyst studies, including various optical, mass­spectrometry, and gas­chromatography techniques. Of these, rapid­scanning Fourier­transform infrared (FTIR) imaging is one of the fastest and most versatile screening techniques. Here, the new design of the 16­channel HT reactor is presented and test results for its accuracy and reproducibility are shown. The performance of the system was evaluated through the oxidation of CO over commercial Pd/Al2O3 and cobalt oxide nanoparticles synthesized with different …

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Photosynthetic Performance And Anti-Oxidative Response Of Cornus Controversa Seedlings Under Cadmium And Lead Stress, Xinyu Huang, Yonglei Jiang, Xiaomao Cheng, Lilan Deng, Xuncheng Liu Jun 2015

Photosynthetic Performance And Anti-Oxidative Response Of Cornus Controversa Seedlings Under Cadmium And Lead Stress, Xinyu Huang, Yonglei Jiang, Xiaomao Cheng, Lilan Deng, Xuncheng Liu

Faculty Publications

The photosynthetic efficiency of Cornus controversa leaves was decreased significantly under Cd treatment while it was not affected by Pb exposure. Cd decreased while Pb treatment increased the chlorophyll contents of Cornus controversa leaves. Furthermore, the peroxidase (GPX) activities were decreased after Cd treatment while elevated by Pb exposure in Cornus controvera seedlings. In addition, both Cd and Pb exposures increased the malondialdehyde (MDA) and proline contents and elevated the superoxide dismutase (SOD) activities of Cornus controvera seedlings. Collectively, these results indicated that Cornus controversa may be more tolerant to Pb than Cd toxicity. This finding will contribute to the …

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Global Technology Experiences For Upper-Division Engineering Students: An Assessment, Patricia Backer, Wenchiang Chung Jun 2015

Global Technology Experiences For Upper-Division Engineering Students: An Assessment, Patricia Backer, Wenchiang Chung

Faculty Publications

In order for students to thrive in the highly competitive global economy, it is critical for them to develop international perspectives and appreciation. As a result, in 2004, the San Jose State University’s Charles W. Davidson College of Engineering established a one-million-dollar Global Technology Initiative (GTI) program. The mission of the GTI program is to expand students’ horizons about the opportunities and challenges of a global economy, to expose them to global, environmental, and energy problems in which technology plays a central role, to motivate their learning of global issues and different cultures, and to introduce them to a more …

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High Aspect Ratio, Carbon Nanotube Membranes Decorated With Pt Nanoparticle Urchins For Micro Underwater Vehicle Propulsion Via H2O2 Decomposition, Kevin M. Marr, Bolin Chen, Eric J. Mootz, Jason Geder, Marius Pruessner, Brian J. Melde, Richard R. Vanfleet, Igor L. Medintz, Brian D. Iverson, Jonathan C. Claussen Jun 2015

High Aspect Ratio, Carbon Nanotube Membranes Decorated With Pt Nanoparticle Urchins For Micro Underwater Vehicle Propulsion Via H2O2 Decomposition, Kevin M. Marr, Bolin Chen, Eric J. Mootz, Jason Geder, Marius Pruessner, Brian J. Melde, Richard R. Vanfleet, Igor L. Medintz, Brian D. Iverson, Jonathan C. Claussen

Faculty Publications

The utility of unmanned Micro Underwater Vehicles (MUVs) is paramount for exploring confined spaces, but their spatial agility is often impaired when maneuvers require burst-propulsion. herein we develop high-aspect ratio (150:1), multi-walled carbon nanotube microarray membranes (CNT-MMs) for propulsive, MUV thrust generation by the decomposition of hydrogen peroxide (H2O2). The CNT-MMs are grown via chemical vapor deposition with diamond shaped pores (nominal diagonal dimensions of 4.5 × 9.0 [µm]) and subsequently decorated with urchin-like, platinum (Pt) nanoparticles via a facile, electroless, chemical deposition process. The Pt-CNT-MMs display robust, high catalytic ability with an effective activation energy …

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Post-Installed Fiber Optic Pressure Sensors On Subsea Production Risers For Severe Slugging Control, Ammon Eaton, Seyed M. Safdarnejad, John Hedengren, Kristi Moffat, Casey Hubbell, David Brower, Alexis Brower Jun 2015

Post-Installed Fiber Optic Pressure Sensors On Subsea Production Risers For Severe Slugging Control, Ammon Eaton, Seyed M. Safdarnejad, John Hedengren, Kristi Moffat, Casey Hubbell, David Brower, Alexis Brower

Faculty Publications

Fiber optic sensors have gained increasing use in monitoring offshore structures. The sensors have successfully monitored flowlines, umbilicals, wells, Tension Leg Platform (TLP) tendons, production and drilling risers, and mooring lines. Fiber optic sensors are capable of monitoring strain, temperature, pressure, and vibration. While the success of fiber optic monitoring has been clearly demonstrated, the sensors are now under consideration for automation applications. This paper details the plausibility of using pressure measurements from post-installed fiber Bragg grating (FBG) sensors with Model Predictive Control (MPC) to suppress severe slugging in subsea risers. Prior control schemes demonstrate that slugging is mitigated using …

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Impact Of Prognostic Uncertainty In System Health Monitoring, Robert M. Vandawaker, David R. Jacques, Jason K. Freels May 2015

Impact Of Prognostic Uncertainty In System Health Monitoring, Robert M. Vandawaker, David R. Jacques, Jason K. Freels

Faculty Publications

Across many industries, systems are exceeding their intended design lives, whether they are ships, bridges or military aircraft. As a result failure rates can increase and unanticipated wear or failure conditions can arise. Health monitoring research and application has the potential to more safely lengthen the service life of a range of systems through utilization of sensor data and knowledge of failure mechanisms to predict component life remaining. A further benefit of health monitoring when combined across an entire platform is system health management. System health management is an enabler of condition based maintenance, which allows repair or replacement based …

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Software In Military Aviation And Drone Mishaps: Analysis And Recommendations For The Investigation Process, Veronica Foreman, Francesca Favaro, Joseph Saleh, Christopher Johnson May 2015

Software In Military Aviation And Drone Mishaps: Analysis And Recommendations For The Investigation Process, Veronica Foreman, Francesca Favaro, Joseph Saleh, Christopher Johnson

Faculty Publications

Software plays a central role in military systems. It is also an important factor in many recent incidents and accidents. A safety gap is growing between our software-intensive technological capabilities and our understanding of the ways they can fail or lead to accidents. Traditional forms of accident investigation are poorly equipped to trace the sources of software failure, for instance software does not age in the same way that hardware components fail over time. As such, it can be hard to trace the causes of software failure or mechanisms by which it contributed to accidents back into the development and …

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Interstitial Silicon Ions In Rutile Tio2 Crystals, Eric M. Golden, Nancy C. Giles, Shan Yang, Larry E. Halliburton Apr 2015

Interstitial Silicon Ions In Rutile Tio2 Crystals, Eric M. Golden, Nancy C. Giles, Shan Yang, Larry E. Halliburton

Faculty Publications

Electron paramagnetic resonance (EPR) is used to identify a new and unique photoactive silicon-related point defect in single crystals of rutile TiO2. The importance of this defect lies in its assignment to interstitial silicon ions and the unexpected establishment of silicon impurities as a major hole trap in TiO2. Principal g values of this new S=1/2 center are 1.9159, 1.9377, and 1.9668 with principal axes along the [¯110],[001], and [110] directions, respectively. Hyperfine structure in the EPR spectrum shows the unpaired spin interacting equally with two Ti nuclei and unequally with two Si nuclei. These silicon …

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Enhancing Grain Boundary Ionic Conductivity In Mixed Ionic–Electronic Conductors, Ye Lin, Shumin Fang, Dong Su, Kyle S. Brinkman, Fanglin Chen Apr 2015

Enhancing Grain Boundary Ionic Conductivity In Mixed Ionic–Electronic Conductors, Ye Lin, Shumin Fang, Dong Su, Kyle S. Brinkman, Fanglin Chen

Faculty Publications

Mixed ionic–electronic conductors are widely used in devices for energy conversion and storage. Grain boundaries in these materials have nanoscale spatial dimensions, which can generate substantial resistance to ionic transport due to dopant segregation. Here, we report the concept of targeted phase formation in a Ce0.8Gd0.2O2−δ–CoFe2O4 composite that serves to enhance the grain boundary ionic conductivity. Using transmission electron microscopy and spectroscopy approaches, we probe the grain boundary charge distribution and chemical environments altered by the phase reaction between the two constituents. The formation of an emergent phase successfully avoids segregation of the Gd dopant and depletion of oxygen vacancies …

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Parameter Estimation For Towed Cable Systems Using Moving Horizon Estimation, Liang Sun, Jeremy Castagno, John Hedengren, Randall Beard Apr 2015

Parameter Estimation For Towed Cable Systems Using Moving Horizon Estimation, Liang Sun, Jeremy Castagno, John Hedengren, Randall Beard

Faculty Publications

This paper presents a strategy for optimal estimation of parameters for towed cable systems using moving horizon estimation (MHE). The main contributions of the work include a novel formulation of MHE using a dead-band that explicitly rejects measurement noise, real-time implementation results, and the investigation of time-varying stochastic disturbances as well as unknown yet constant disturbances. Further analysis is conducted on the observability and sensitivity of key parameters to determine which parameters can be estimated by the proposed approach using real-time streaming data from experiments. In addition to the real-time results, an offline multiobjective optimization is conducted to reveal the …

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Youth And The Posthuman: Personhood, Transcendence, And Siri, Erik Leafblad, Andrew Root Apr 2015

Youth And The Posthuman: Personhood, Transcendence, And Siri, Erik Leafblad, Andrew Root

Faculty Publications

When everything gets turned into a technology, and existence is about practical mastery, the mystery of being is buried and everything is made an object, blurring the lines between human personhood and other technological objects.

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Detect And Avoid For Small Unmanned Aircraft Systems Using Ads-B, Timothy Mclain, Laith R. Sahawneh, Matthew O. Duffield, Randall W. Beard Apr 2015

Detect And Avoid For Small Unmanned Aircraft Systems Using Ads-B, Timothy Mclain, Laith R. Sahawneh, Matthew O. Duffield, Randall W. Beard

Faculty Publications

With the increasing demand to integrate unmanned aircraft systems (UAS) into the National Airspace System (NAS), new procedures and technologies are necessary to ensure safe airspace operations and minimize the impact of UAS on current airspace users. Currently, small UAS face limitations on their use in civil airspace because they lack the ability to detect and avoid other aircraft. This article presents a framework that consists of an Automatic Dependent Surveillance-Broadcast (ADS-B)-based sensor, track estimator, conflict/collision detection, and resolution that mitigates collision risk. ADS-B offers long-range, omni-directional intruder detection with comparatively few size, weight, power, and cost demands. The proposed …

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Surface Oxidation Energetics And Kinetics On Mos2 Monolayer, Santosh Kc, Roberto Longo, Robert Wallace, Kyeongjae Cho Apr 2015

Surface Oxidation Energetics And Kinetics On Mos2 Monolayer, Santosh Kc, Roberto Longo, Robert Wallace, Kyeongjae Cho

Faculty Publications

In this work, surface oxidation of monolayer MoS2 (one of the representative semiconductors in transition-metal dichalcogenides) has been investigated using density functional theory method. Oxygen interaction with MoS2 shows that, thermodynamically, the surface tends to be oxidized. However, the dissociative absorption of molecular oxygen on the MoS2 surface is kinetically limited due to the large energy barrier at low temperature. This finding elucidates the air stability of MoS2 surface in the atmosphere. Furthermore, the presence of defects significantly alters the surface stability and adsorption mechanisms. The electronic properties of the oxidized surface have been examined as a function of oxygen …

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Insights Into Ultrasonic Release From Eliposomes, Marjan Javadi, William G. Pitt Mar 2015

Insights Into Ultrasonic Release From Eliposomes, Marjan Javadi, William G. Pitt

Faculty Publications

A novel nanosized liposomal carrier was prepared consisting of perfluorocarbon emulsion droplet(s) encapsulated inside a liposome, which is called an eLiposome. This 200-nm construct is useful for acoustically activated drug delivery because ultrasound causes the emulsion droplet to expand from liquid to gas, which expansion ruptures the eLiposome bilayer and releases the internal contents. This study focuses on the parameters that influence control of the release of calcein (a model drug), including ultrasound amplitude, insonation time, and perfluorocarbon vapor pressure as a function of temperature and composition. The results show that calcein release increases as the ultrasound amplitude or insonation …

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Heterogeneous Catalyst Deactivation And Regeneration: A Review, Morris D. Argyle, Calvin H. Bartholomew Feb 2015

Heterogeneous Catalyst Deactivation And Regeneration: A Review, Morris D. Argyle, Calvin H. Bartholomew

Faculty Publications

Deactivation of heterogeneous catalysts is a ubiquitous problem that causes loss of catalytic rate with time. This review on deactivation and regeneration of heterogeneous catalysts classifies deactivation by type (chemical, thermal, and mechanical) and by mechanism (poisoning, fouling, thermal degradation, vapor formation, vapor-solid and solid-solid reactions, and attrition/crushing). The key features and considerations for each of these deactivation types is reviewed in detail with reference to the latest literature reports in these areas. Two case studies on the deactivation mechanisms of catalysts used for cobalt Fischer-Tropsch and selective catalytic reduction are considered to provide additional depth in the topics of …

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A Cloud-Based Modflow Service For Aquifer Management Decision Support, David Jones, Norm Jones, James Greer, Jim Nelson Feb 2015

A Cloud-Based Modflow Service For Aquifer Management Decision Support, David Jones, Norm Jones, James Greer, Jim Nelson

Faculty Publications

A framework to publish simplified MODFLOW groundwater modeling capabilities to a web interface for use by water managers and stakeholders is presented. Numerical modeling simulations can assist aquifer management decisions, but the amount of time and professional expertise required to wield modern groundwater models often exceeds the resources of regulating agencies – even for simple modeling tasks that are repetitive in nature. The framework is capable of automating such modeling tasks, accepting user input, executing MODFLOW, and generating specialized results including maps and modeling reports. This framework was used to build a pilot system for an aquifer in central Utah, …

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Experimental Measurements Of The Spectral Absorption Coefficient Of Pure Fused Silica Optical Fibers, Travis J. Moore, Matthew R. Jones Feb 2015

Experimental Measurements Of The Spectral Absorption Coefficient Of Pure Fused Silica Optical Fibers, Travis J. Moore, Matthew R. Jones

Faculty Publications

Knowledge of the spectral absorption coefficient of fused silica optical fibers is important in modeling heat transfer in the processes and applications in which these fibers are used. An experimental method used to measure the spectral absorption coefficient of optical fibers is presented. Radiative energy from a blackbody radiator set at different temperatures is directed through the optical fibers and into an FTIR spectrometer. Spectral instrument response functions are calculated for different fiber lengths. The ratios of the slopes of the instrument response functions for the different lengths of fibers are used to solve for the spectral absorption coefficient of …

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Experimental Characterization And Correlation Analysis Of Indoor Channels At 15 Ghz, Xin Zhou, Zhangdui Zhong, Bei Zhang, Ruisi He, Ke Guan, Qi Wang, David W. Matolak Feb 2015

Experimental Characterization And Correlation Analysis Of Indoor Channels At 15 Ghz, Xin Zhou, Zhangdui Zhong, Bei Zhang, Ruisi He, Ke Guan, Qi Wang, David W. Matolak

Faculty Publications

The indoor radio channels at 15 GHz are investigated based on measurements. The large- and small-scale fading behaviors as well as the delay dispersion characteristics are discussed. It is found that the large-scale fading, Ricean -factor, and delay spread can be described by log-normal distributions. Furthermore, both autocorrelation and cross correlation properties of the above parameters are analyzed and modeled. These parameters characterize fading and delay behaviors as well as their mutual dependency and can be used as empirical values for future wireless system design and simulation in 15 GHz short-range indoor channels.

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A Review Of Open Source Software Solutions For Developing Water Resources Web Applications, Nathan R. Swain, Kilisimasi Latu, Scott D. Christensen, Norman L. Jones, E. James Nelson, Daniel P. Ames, Gustavious P. Williams Feb 2015

A Review Of Open Source Software Solutions For Developing Water Resources Web Applications, Nathan R. Swain, Kilisimasi Latu, Scott D. Christensen, Norman L. Jones, E. James Nelson, Daniel P. Ames, Gustavious P. Williams

Faculty Publications

Water resources web applications or “web apps” are growing in popularity as a means to overcome many of the challenges associated with hydrologic simulations in decision-making. Water resources web apps fall outside of the capabilities of standard web development software, because of their spatial data components. These spatial data needs can be addressed using a combination of existing free and open source software (FOSS) for geographic information systems (FOSS4G) and FOSS for web development. However, the abundance of FOSS projects that are available can be overwhelming to new developers. In an effort to understand the web of FOSS features and …

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Non-Dimensional Approach For Static Balancing Of Rotational Flexures, Ezekiel G. Merriam, Larry L. Howell Feb 2015

Non-Dimensional Approach For Static Balancing Of Rotational Flexures, Ezekiel G. Merriam, Larry L. Howell

Faculty Publications

This work presents a nondimensional method for statically balancing flexural hinges, including those with stiffness that varies with load. Using a set of non-dimensional parameters, it is shown that one can quickly design a balancing mechanism for an idealized hinge/torsion spring system. This method is then extended to load-dependent systems, and is demonstrated with the design of a balanced cross-axis-flexural pivot with stiffness that varies as a function of compressive preload. A physical prototype is built and tested to verify the design method. The prototype demonstrates an average stiffness reduction of 87% over an 80 degree deflection range. The method …

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Con-Resistant Trust For Improved Reliability In A Smart Grid Special Protection System, Crystal M. Shipman, Kenneth M. Hopkinson, Juan L. Lopez Jr. Feb 2015

Con-Resistant Trust For Improved Reliability In A Smart Grid Special Protection System, Crystal M. Shipman, Kenneth M. Hopkinson, Juan L. Lopez Jr.

Faculty Publications

This paper applies a con-resistant trust mechanism to improve the performance of a communications-based special protection system to enhance its effectiveness and resiliency. Smart grids incorporate modern information technologies to increase reliability and efficiency through better situational awareness. However, with the benefits of this new technology come the added risks associated with threats and vulnerabilities to the technology and to the critical infrastructure it supports. The research in this paper uses con-resistant trust to quickly identify malicious or malfunctioning (untrustworthy) protection system nodes to mitigate instabilities. The con-resistant trust mechanism allows protection system nodes to make trust assessments based on …

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Electrochemical Capture Of Co2 From Natural Gas Using A High-Temperature Ceramic-Carbonate Membrane, Jingjing Tong, Lingling Zhan, Jie Fang, Minfang Han, Kevin Huang Jan 2015

Electrochemical Capture Of Co2 From Natural Gas Using A High-Temperature Ceramic-Carbonate Membrane, Jingjing Tong, Lingling Zhan, Jie Fang, Minfang Han, Kevin Huang

Faculty Publications

This study reports the first investigation of using a ceramic-carbonate dual-phase membrane to electrochemically separate CO2 from a simulated natural gas. The CO2 permeation flux density was systematically studied as a function of temperature, CO2 partial pressure and time. As expected, the flux density was observed to increase with temperature and CO2 partial pressure. Long-term stability test showed that flux density experienced an initial performance-improving “break-in” period followed by a slow decay. Post-test microstructural analysis suggested that a gradual loss of carbonate during the test could be the cause of the flux-time behavior observed.

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Theoretical Investigation Of Stabilities And Optical Properties Of Si12C12 Clusters, Xiaofeng F. Duan, Larry W. Burggraf Jan 2015

Theoretical Investigation Of Stabilities And Optical Properties Of Si12C12 Clusters, Xiaofeng F. Duan, Larry W. Burggraf

Faculty Publications

By sorting through hundreds of globally stable Si12C12 isomers using a potential surface search and using simulated annealing, we have identified low-energy structures. Unlike isomers knit together by Si–C bonds, the lowest energy isomers have segregated carbon and silicon regions that maximize stronger C–C bonding. Positing that charge separation between the carbon and silicon regions would produce interesting optical absorption in these cluster molecules, we used time-dependent density functional theory to compare the calculated optical properties of four isomers representing structural classes having different types of silicon and carbon segregation regions. Absorptions involving charge transfer between segregated …

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Two-Dimensional Temperature Analysis Of Nuclear Fireballs Using Digitized Film, Robert C. Slaughter, Tyler R. Peery, John W. Mcclory Jan 2015

Two-Dimensional Temperature Analysis Of Nuclear Fireballs Using Digitized Film, Robert C. Slaughter, Tyler R. Peery, John W. Mcclory

Faculty Publications

Researchers at Lawrence Livermore National Laboratory have begun digitizing technical films spanning the atmospheric nuclear testing operations conducted by the United States from 1945 through 1962. Each atmospheric nuclear test was filmed by Edgerton, Germeshausen, and Grier, Inc., using between 20 to 40 cameras per test. These technical film test data represent a primary source for advancing the knowledge of nuclear weapon output as well as the understanding of nonnuclear high-temperature gases. This manuscript outlines the procedures followed in order to perform two-dimensional temperature calculations for early time nuclear fireballs using digitized film. The digitized optical densities of the film …

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The Effects Of Multiple Probes On The Hybridization Of Target Dna On Surfaces, Ryan C. Welling, Thomas A. Knotts Iv Jan 2015

The Effects Of Multiple Probes On The Hybridization Of Target Dna On Surfaces, Ryan C. Welling, Thomas A. Knotts Iv

Faculty Publications

DNA microarrays have disruptive potential in many fields including genetics and medicine, but the technology has yet to find widespread clinical use due to poor reliability. Microarrays work on the principle of hybridization and can only be as dependable as this process is reliable. As such, a significant amount of theoretical research has been done to understand hybridization on surfaces on the molecular level. Previous simulations of a target strand with a single, surface-tethered probe molecule have yielded valuable insights, but such is an ideal system and little is known about the effects of multiple probes—a situation that more closely …

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Thorough Exploration Of Complex Environments With A Space-Based Potential Field, Kenealy Alina, Nicholas Primiano, Alex Keyes, Lyons Damian Jan 2015

Thorough Exploration Of Complex Environments With A Space-Based Potential Field, Kenealy Alina, Nicholas Primiano, Alex Keyes, Lyons Damian

Faculty Publications

Robotic exploration, for the purposes of search and rescue or explosive device detection, can be improved by using a team of multiple robots. Potential field navigation methods offer natural and efficient distributed exploration algorithms in which team members are mutually repelled to spread out and cover the area efficiently. However, they also suffer from field minima issues. Liu and Lyons proposed a Space-Based Potential Field (SBPF) algorithm that disperses robots efficiently and also ensures they are driven in a distributed fashion to cover complex geometry. In this paper, the approach is modified to handle two problems with the original SBPF …

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Homing With Stereovision, Paramesh Nirmal, Damian Lyons Jan 2015

Homing With Stereovision, Paramesh Nirmal, Damian Lyons

Faculty Publications

Visual Homing is a navigation method based on comparing a stored image of a goal location to the current image to determine how to navigate to the goal location. It is theorized that insects such as ants and bees employ visual homing techniques to return to their nest or hive, and inspired by this, several researchers have developed elegant robot visual homing algorithms. Depth information, from visual scale, or other modality such as laser ranging, can improve the quality of homing. While insects are not well equipped for stereovision, stereovision is an effective robot sensor. We describe the challenges involved …

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Evaluation Of Parallel Reduction Strategies For Fusion Of Sensory Information From A Robot Team., Damian M. Lyons, Joseph Leroy Jan 2015

Evaluation Of Parallel Reduction Strategies For Fusion Of Sensory Information From A Robot Team., Damian M. Lyons, Joseph Leroy

Faculty Publications

The advantage of using a team of robots to search or to map an area is that by navigating the robots to different parts of the area, searching or mapping can be completed more quickly. A crucial aspect of the problem is the combination, or fusion, of data from team members to generate an integrated model of the search/mapping area. In prior work we looked at the issue of removing mutual robots views from an integrated point cloud model built from laser and stereo sensors, leading to a cleaner and more accurate model. This paper addresses a further challenge: Even …

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Leveraging Area Bounds Information For Autonomous Decentralized Multi-Robot Exploration, Tsungming Liu, Damian Lyons Jan 2015

Leveraging Area Bounds Information For Autonomous Decentralized Multi-Robot Exploration, Tsungming Liu, Damian Lyons

Faculty Publications

This paper proposes a simple and uniform, decentralized approach to the problem of dispersing a team of robots to explore an area quickly. The Decentralized Space-Based Potential Field (D-SBPF) algorithm is a potential field approach that leverages knowledge of the overall bounds of the area to be explored. It includes a monotonic coverage factor in the potential field to avoid minima, realistic sensor bounds, and a distributed map exchange protocol. The D-SBPF approach yields a simple potential field control strategy for all robots but nonetheless has good dispersion and overlap performance in exploring areas with convex geometry while avoiding potential …

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Performance Verification For Behavior-Based Robot Missions, Damian M. Lyons, Ron Arkin, Shu Jiang, Tsungming Liu, Paramesh Nirmal Jan 2015

Performance Verification For Behavior-Based Robot Missions, Damian M. Lyons, Ron Arkin, Shu Jiang, Tsungming Liu, Paramesh Nirmal

Faculty Publications

Certain robot missions need to perform predictably in a physical environment that may have significant uncertainty. One approach is to leverage automatic software verification techniques to establish a performance guarantee. The addition of an environment model and uncertainty in both program and environment, however, means the state-space of a model-checking solution to the problem can be prohibitively large. An approach based on behavior-based controllers in a process-algebra framework that avoids state-space combinatorics is presented here. In this approach, verification of the robot program in the uncertain environment is reduced to a filtering problem for a Bayesian Network. Validation results are …

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