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- Institution
- Keyword
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- Nonlinear Control Systems (4)
- Optimal Control (4)
- Neurocontrollers (3)
- Adaptive Control (2)
- Lyapunov Methods (2)
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- Observers (2)
- Acoustic emission testing (1)
- Aerospace Control (1)
- Aluminium Alloys (1)
- Closed Loop Systems (1)
- Collision avoidance (1)
- Collocation Points (1)
- Composite materials (1)
- Computational Argumentation (1)
- Conflict Resolution (1)
- Control System Synthesis (1)
- Cool flames; Flame speed; Low-temperature combustion; Reducedgravity (1)
- Cooperative control (1)
- Corrosion Testing (1)
- Crack detection (1)
- Density (1)
- Design Repository (1)
- Discrete Time Systems (1)
- Discrete-time systems (1)
- Distributed Parameter Systems (1)
- Eddy Current Testing (1)
- Efficient Sampling (1)
- Electric discharges (1)
- Electrolyte solutions (1)
- Electromagnetic Torque (1)
- Publication
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- Mechanical and Aerospace Engineering Faculty Research & Creative Works (10)
- Electrical and Computer Engineering Faculty Research & Creative Works (6)
- Opportunities for Undergraduate Research Experience Program (OURE) (5)
- Computer Science Faculty Research & Creative Works (1)
- Faculty Publications - Biomedical, Mechanical, and Civil Engineering (1)
Articles 1 - 25 of 25
Full-Text Articles in Mechanical Engineering
Optimal Control Of Class Of Non-Linear Plants Using Artificial Immune Systems: Application Of The Clonal Selection Algorithm, S. A. Panimadai Ramaswamy, Ganesh K. Venayagamoorthy, S. N. Balakrishnan
Optimal Control Of Class Of Non-Linear Plants Using Artificial Immune Systems: Application Of The Clonal Selection Algorithm, S. A. Panimadai Ramaswamy, Ganesh K. Venayagamoorthy, S. N. Balakrishnan
Electrical and Computer Engineering Faculty Research & Creative Works
The function of natural immune system is to protect the living organisms against invaders/pathogens. Artificial Immune System (AIS) is a computational intelligence paradigm inspired by the natural immune system. Diverse engineering problems have been solved in the recent past using AIS. Clonal selection is one of the few algorithms that belong to the family of AIS techniques. Clonal selection algorithm is the computational implementation of the clonal selection principle. The process of affinity maturation of the immune system is explicitly incorporated in this algorithm. This paper presents the application of AIS for the optimal control of a class of non-linear …
Cooperative Uav Formation Flying With Obstacle/Collision Avoidance, Xiaohua Wang, Vivek Yadav, S. N. Balakrishnan
Cooperative Uav Formation Flying With Obstacle/Collision Avoidance, Xiaohua Wang, Vivek Yadav, S. N. Balakrishnan
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Navigation problems of unmanned air vehicles (UAVs) flying in a formation in a free and an obstacle-laden environment are investigated in this brief. when static obstacles popup during the flight, the UAVs are required to steer around them and also avoid collisions between each other. In order to achieve these goals, a new dual-mode control strategy is proposed: a “safe mode” is defined as an operation in an obstacle-free environment and a “danger mode” is activated when there is a chance of collision or when there are obstacles in the path. Safe mode achieves global optimization because the dynamics of …
Reinforcement Learning Based Output-Feedback Control Of Nonlinear Nonstrict Feedback Discrete-Time Systems With Application To Engines, Peter Shih, Jonathan B. Vance, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier
Reinforcement Learning Based Output-Feedback Control Of Nonlinear Nonstrict Feedback Discrete-Time Systems With Application To Engines, Peter Shih, Jonathan B. Vance, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier
Electrical and Computer Engineering Faculty Research & Creative Works
A novel reinforcement-learning based output-adaptive neural network (NN) controller, also referred as the adaptive-critic NN controller, is developed to track a desired trajectory for a class of complex nonlinear discrete-time systems in the presence of bounded and unknown disturbances. The controller includes an observer for estimating states and the outputs, critic, and two action NNs for generating virtual, and actual control inputs. The critic approximates certain strategic utility function and the action NNs are used to minimize both the strategic utility function and their outputs. All NN weights adapt online towards minimization of a performance index, utilizing gradient-descent based rule. …
Management Of An Intelligent Argumentation Network For A Web-Based Collaborative Engineering Design Environment, Xiaoqing Frank Liu, Man Zheng, Ganesh K. Venayagamoorthy, Ming-Chuan Leu
Management Of An Intelligent Argumentation Network For A Web-Based Collaborative Engineering Design Environment, Xiaoqing Frank Liu, Man Zheng, Ganesh K. Venayagamoorthy, Ming-Chuan Leu
Computer Science Faculty Research & Creative Works
Conflict resolution is one of the most challenging tasks in collaborative engineering design. In our previous research, a web-based intelligent collaborative system was developed to address this challenge based on intelligent computational argumentation. However, two important issues were not resolved in that system: priority of participants and self-conflicting arguments. In this paper, we develop two methods for incorporating priorities of participants into the computational argumentation network: 1) weighted summation and 2) re-assessment of strengths of arguments based on priority of owners of the argument using fuzzy logic inference. In addition, we develop a method for detection of self-conflicting arguments. Incorporation …
Coupled-Mode Theory For Stimulated Raman Scattering In High-Q/Vm Silicon Photonic Band Gap Defect Cavity Lasers, Xiaodong Yang, C. W. Wong
Coupled-Mode Theory For Stimulated Raman Scattering In High-Q/Vm Silicon Photonic Band Gap Defect Cavity Lasers, Xiaodong Yang, C. W. Wong
Mechanical and Aerospace Engineering Faculty Research & Creative Works
We examine the dynamics of stimulated Raman scattering in designed high-Q/Vm silicon photonic band gap nanocavities through the coupled-mode theory framework towards optically-pumped silicon lasing. The interplay of other X(3) effects such as two-photon absorption and optical Kerr, related free-carrier dynamics, thermal effects, as well as linear losses such as cavity radiation and linear material absorption are included and investigated numerically. Our results clarify the relative contributions and evolution of the mechanisms, and demonstrate the lasing and shutdown thresholds. Our studies illustrate the conditions for continuous-wave and pulsed highly-efficient Raman frequency conversion for practical realization in monolithic silicon …
Concepts For The Nanosat- 5 Satellite Design Competition, Sunil C. Aggarwal
Concepts For The Nanosat- 5 Satellite Design Competition, Sunil C. Aggarwal
Opportunities for Undergraduate Research Experience Program (OURE)
This paper presents feasible small space satellite missions which are of interest to the U.S. Air Force and can be used to get selected and win the NANOSAT-5 satellite design competition. Some thought on which of these missions can be used by the University of Missouri-Rolla to successfully take part in the competition hate also been presented.
Computational Study Of Laminar Separation Bubble Development Over Supersonic Airfoils At Subsonic Speeds, Josiah D. Elliott
Computational Study Of Laminar Separation Bubble Development Over Supersonic Airfoils At Subsonic Speeds, Josiah D. Elliott
Opportunities for Undergraduate Research Experience Program (OURE)
Laminar Separation Bubbles (LSBs) are regions of separated flow that start near the leading edge of an airfoil and reattach further down the airfoil surface. These regions of separation can appear at low angles of attack and can grow significantly as the angle of attack is increased heavily influencing the flow characteristics over the airfoil. Research on this topic is driven by the supersonic business jet industry which has a particular interest in this type of research due to performance requirements in both the subsonic and supersonic flight regimes. This manuscript is focused on the flow developments near the sharp …
Parallel Machin E Tool Development, Adam Bunton
Parallel Machin E Tool Development, Adam Bunton
Opportunities for Undergraduate Research Experience Program (OURE)
The work done during this OURE centered on the parallel machining center that is under development by a research group led by Dr. R. Landers. The specific tasks associated with this research involved the design of several parts, documentation of the processes for assembly and operation, procurement of some materials and stock parts, and involvement with experiments with the machine tool. These various aspects are outlined in the following report, with emphasis on the design of components.
Mechanical Characterization Of Spherical Hydrogels: Contact Diameter Measurement, Joshua Bunch
Mechanical Characterization Of Spherical Hydrogels: Contact Diameter Measurement, Joshua Bunch
Opportunities for Undergraduate Research Experience Program (OURE)
In an effort to develop new ophthalmic treatments revolving around the ocular lens, the mechanical characteristics of natural ocular lenses and synthetic models must be determined and compared. One mechanical characteristic that is necessary when making comparisons is the variation of contact circle diameter or contact area with varying strains. A method was used in this experiment to measure the varying contact circle diameter of spherical hydrogels at strains up to 15%. This method could be used to estimate the varying contact diameter of other similar materials such as natural ocular lenses if the precision of the method is improved. …
Efficient Sampling For Non-Intrusive Polynomial Chaos Applications With Multiple Uncertain Input Variables, Serhat Hosder, Robert W. Walters, Michael Balch
Efficient Sampling For Non-Intrusive Polynomial Chaos Applications With Multiple Uncertain Input Variables, Serhat Hosder, Robert W. Walters, Michael Balch
Mechanical and Aerospace Engineering Faculty Research & Creative Works
The accuracy and the computational efficiency of a Point-Collocation Non-Intrusive Polynomial Chaos (NIPC) method applied to stochastic problems with multiple uncertain input variables has been investigated. Two stochastic model problems with multiple uniform random variables were studied to determine the effect of different sampling methods (Random, Latin Hypercube, and Hammersley) for the selection of the collocation points. The effect of the number of collocation points on the accuracy of polynomial chaos expansions were also investigated. The results of the stochastic model problems show that all three sampling methods exhibit a similar performance in terms of the the accuracy and the …
Mechanical Fastener Pull-Out In Recycled Plastic Lumber, Ryan Dusheke
Mechanical Fastener Pull-Out In Recycled Plastic Lumber, Ryan Dusheke
Opportunities for Undergraduate Research Experience Program (OURE)
The purpose of this paper is to present test results for the examination of mechanical fastener pull-out in plastic lumber. The testing was performed on both 1 Od galvanized steel nails, nominally 3" long and 0.148" in diameter, and No. 10 flathead low-carbon steel screws, nominally I" long. l "x6" Trimax plastic lumber, produced by US Plastic Lumber, was used for all testing. Tests were performed in each of the three sides of the boards. To evaluate the performance of the materials in varying conditions, testing was performed at -20°f, room temperature, and 125°f.
Impact-Induced Damage Characterization Of Composite Plates Using Neural Networks, Steve Eugene Watkins, Farhad Akhavan, Rohit Dua, K. Chandrashekhara, Donald C. Wunsch
Impact-Induced Damage Characterization Of Composite Plates Using Neural Networks, Steve Eugene Watkins, Farhad Akhavan, Rohit Dua, K. Chandrashekhara, Donald C. Wunsch
Electrical and Computer Engineering Faculty Research & Creative Works
Impact-induced damage in fiber-reinforced laminated composite plates is characterized. An instrumented impact tower was used to carry out low-velocity impacts on thirteen clamped glass/epoxy composite plates. A range of impact energies was experimentally investigated by progressively varying impactor masses (holding the impact height constant) and varying impact heights (holding the impactor mass constant). The in-plane strain profiles as measured by polyvinylidene fluoride (PVDF) piezoelectric sensors are shown to indicate damage initiation and to correlate to impact energy. Plate damage included matrix cracking, fiber breakage, and delamination. Electronic shearography validated the existence of the impact damage and demonstrated an actual damage …
Multifrequency Eddy Current Inspection Of Corrosion In Clad Aluminum Riveted Lap Joints And Its Effect On Fatigue Life, Shridhar Natarajan, Anthony Chukwujekwu Okafor
Multifrequency Eddy Current Inspection Of Corrosion In Clad Aluminum Riveted Lap Joints And Its Effect On Fatigue Life, Shridhar Natarajan, Anthony Chukwujekwu Okafor
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Aging aircraft are prone to corrosion damage and fatigue cracks in riveted lap joints of fuselage skin panels. This can cause catastrophic failure if not detected and repaired. Hence detection of corrosion damage and monitoring its effect on structural integrity are essential. This paper presents multifrequency eddy current (EC) inspection of corrosion damage and machined material loss defect in clad A1 2024-T3 riveted lap joints and its effect on fatigue life. Results of eddy current inspection, corrosion product removal and fatigue testing are presented.
Cool Flame Propagation Speeds, Michael R. Foster, Howard Pearlman
Cool Flame Propagation Speeds, Michael R. Foster, Howard Pearlman
Faculty Publications - Biomedical, Mechanical, and Civil Engineering
Cool flames are studied at reduced-gravity in a closed, unstirred, spherical reactor to minimize complexities associated with natural convection. Under such conditions, transport is controlled by diffusive fluxes and the flames are observed to propagate radially outward from the center of the reactor toward the wall. Intensified video records are obtained and analyzed to determine the flame radius as a function of time for different vessel temperatures (593–623 K) and initial pressures (55.2–81.4 kPa) using an equimolar (Ø = 5) propane-oxygen premixture. Polynomial-fits are applied to the data and differentiated to determine the cool flame propagation speeds. In nearly …
Product Family Design Knowledge Representation, Aggregation, Reuse, And Analysis, Jyotirmaya Nanda, Henri Thevenot, Timothy W. Simpson, Robert B. Stone, Matt R. Bohm, Steven B. Shooter
Product Family Design Knowledge Representation, Aggregation, Reuse, And Analysis, Jyotirmaya Nanda, Henri Thevenot, Timothy W. Simpson, Robert B. Stone, Matt R. Bohm, Steven B. Shooter
Mechanical and Aerospace Engineering Faculty Research & Creative Works
A flexible information model for systematic development and deployment of product families during all phases of the product realization process is crucial for product-oriented organizations. In current practice, information captured while designing products in a family is often incomplete, unstructured, and is mostly proprietary in nature, making it difficult to index, search, refine, reuse, distribute, browse, aggregate, and analyze knowledge across heterogeneous organizational information systems. To this end, we propose a flexible knowledge management framework to capture, reorganize, and convert both linguistic and parametric product family design information into a unified network, which is called a networked bill of material …
Robust/Optimal Temperature Profile Control Of A High-Speed Aerospace Vehicle Using Neural Networks, Vivek Yadav, Radhakant Padhi, S. N. Balakrishnan
Robust/Optimal Temperature Profile Control Of A High-Speed Aerospace Vehicle Using Neural Networks, Vivek Yadav, Radhakant Padhi, S. N. Balakrishnan
Mechanical and Aerospace Engineering Faculty Research & Creative Works
An approximate dynamic programming (ADP)-based suboptimal neurocontroller to obtain desired temperature for a high-speed aerospace vehicle is synthesized in this paper. a 1-D distributed parameter model of a fin is developed from basic thermal physics principles. ldquoSnapshotrdquo solutions of the dynamics are generated with a simple dynamic inversion-based feedback controller. Empirical basis functions are designed using the ldquoproper orthogonal decompositionrdquo (POD) technique and the snapshot solutions. a low-order nonlinear lumped parameter system to characterize the infinite dimensional system is obtained by carrying out a Galerkin projection. an ADP-based neurocontroller with a dual heuristic programming (DHP) formulation is obtained with a …
Determination Of Laser Absorption Coefficients Of Gas Mixtures Using An Ab Initio Md Model, Zhi Liang, Hai-Lung Tsai, Lan Jiang
Determination Of Laser Absorption Coefficients Of Gas Mixtures Using An Ab Initio Md Model, Zhi Liang, Hai-Lung Tsai, Lan Jiang
Mechanical and Aerospace Engineering Faculty Research & Creative Works
In an Effort to Study the Laser Induced Dissociation of Gas Mixtures for an Ongoing Research Project on Diamond Thin Film Coating using Multiple Lasers, It is Necessary to Determine the Absorption Coefficient of Laser Energy by CO2 Gas. an Ab Initio Molecular Dynamics (AIMD) Model is Used to Determine the Laser Absorption Coefficient of CO2 Gas as a Function of Laser Wavelength and Gas Temperature. the Translational, Rotational, and Vibration Motions of Molecules Are All Taken into Account in Our Model. the Intra-Molecular Potential Energy is Obtained by Solving the Kohn-Sham Equation. the Projector-Augmented Wave (PAW) Exchange-Correlation Potential Function …
Incorporating The Effects Of Magnetic Saturation In A Coupled-Circuit Model Of A Claw-Pole Alternator, Hua Bai, Steven Pekarek, Jerry L. Tichenor, Walter Eversman, Duane J. Buening, Gregory R. Holbrook, Ronald J. Krefta
Incorporating The Effects Of Magnetic Saturation In A Coupled-Circuit Model Of A Claw-Pole Alternator, Hua Bai, Steven Pekarek, Jerry L. Tichenor, Walter Eversman, Duane J. Buening, Gregory R. Holbrook, Ronald J. Krefta
Electrical and Computer Engineering Faculty Research & Creative Works
A method of representing the effects of magnetic saturation in a coupled-circuit model of a claw-pole alternator is presented. In the approach considered, the airgap flux density produced by each winding is expressed as a function of magnetic operating point. A challenge in the implementation is that the airgap flux densities consist of several significant harmonics, each of which changes at a distinct rate as iron saturates. Despite this complication, it is shown that relatively simple measurements can be used to determine model parameters. The model is implemented in the analysis of several alternator/rectifier systems using a commercial state-model-based circuit …
Near Optimal Output-Feedback Control Of Nonlinear Discrete-Time Systems In Nonstrict Feedback Form With Application To Engines, Peter Shih, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier
Near Optimal Output-Feedback Control Of Nonlinear Discrete-Time Systems In Nonstrict Feedback Form With Application To Engines, Peter Shih, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier
Electrical and Computer Engineering Faculty Research & Creative Works
A novel reinforcement-learning based output-adaptive neural network (NN) controller, also referred as the adaptive-critic NN controller, is developed to track a desired trajectory for a class of complex nonlinear discrete-time systems in the presence of bounded and unknown disturbances. The controller includes an observer for estimating states and the outputs, critic, and two action NNs for generating virtual, and actual control inputs. The critic approximates certain strategic utility function and the action NNs are used to minimize both the strategic utility function and their outputs. All NN weights adapt online towards minimization of a performance index, utilizing gradient-descent based rule. …
Optimal Neuro-Controller Synthesis For Impulse-Driven System, Xiaohua Wang, S. N. Balakrishnan
Optimal Neuro-Controller Synthesis For Impulse-Driven System, Xiaohua Wang, S. N. Balakrishnan
Mechanical and Aerospace Engineering Faculty Research & Creative Works
This paper presents a new controller design technique for systems driven with impulse inputs. Necessary conditions for optimal impulse control are derived. A neural network structure to solve the resulting equations is presented. The solution concepts are illustrated with a few example problems that exhibit increasing levels of difficulty. Two linear problems-one scalar and one vector-and a benchmark nonlinear problem-Van Der Pol oscillator-are used as case studies. Numerical results show the efficacy of the new solution process for impulse driven systems. Since the theoretical development and the design technique are free from restrictive assumptions, this technique is applicable to many …
The Effects Of Charging By Ultraviolet Light On Granular Lunar Simulant In A Microgravity Environment, Sydney J. Chamberlin, Troy Munro, Sarah Isert, Tracy Garin Savage
The Effects Of Charging By Ultraviolet Light On Granular Lunar Simulant In A Microgravity Environment, Sydney J. Chamberlin, Troy Munro, Sarah Isert, Tracy Garin Savage
Reports and Proposals
No abstract provided.
Modeling Redox-Based Magnetohydrodynamics In Three-Dimensional Microfluidic Channels, Hussameddine S. Kabbani, Aihua Wang, Xiaobing Luo, Shizhi Qian
Modeling Redox-Based Magnetohydrodynamics In Three-Dimensional Microfluidic Channels, Hussameddine S. Kabbani, Aihua Wang, Xiaobing Luo, Shizhi Qian
Mechanical Engineering Faculty Research
RedOx-based magnetohydrodynamic MHD[1] flows in three-dimensional microfluidic channels are investigated theoretically with a coupled mathematical model consisting of the Nernst-Planck equations for the concentrations of ionic species, the local electroneutrality condition for the electric potential, and the Navier-Stokes equations for the flow field. A potential difference is externally applied across two planar electrodes positioned along the opposing walls of a microchannel that is filled with a dilute RedOx electrolyte solution, and a Faradaic current transmitted through the solution results. The entire device is positioned under a magnetic field which can be provided by either a permanent magnet or an electromagnet. …
Simple Penning Ion Source For Laboratory Research And Development Applications, Joshua L. Rovey, Brandon P. Ruzic, Thomas J. Houlahan
Simple Penning Ion Source For Laboratory Research And Development Applications, Joshua L. Rovey, Brandon P. Ruzic, Thomas J. Houlahan
Mechanical and Aerospace Engineering Faculty Research & Creative Works
A simple Penning ion generator (PIG) that can be easily fabricated with simple machining skills and standard laboratory accessories is described. The PIG source uses an iron cathode body, samarium cobalt permanent magnet, stainless steel anode, and iron cathode faceplate to generate a plasma discharge that yields a continuous 1 mA beam of positively charged hydrogen ions at 1 mTorr of pressure. This operating condition requires 5.4 kV and 32.4 W of power. Operation with helium is similar to hydrogen. The ion source is being designed and investigated for use in a sealed-tube neutron generator; however, this ion source is …
Acoustic Emission Detection And Prediction Of Fatigue Crack Propagation In Composite Patch Repairs Using Neural Networks, Navdeep Singh, Navrag Singh, Anthony Chukwujekwu Okafor
Acoustic Emission Detection And Prediction Of Fatigue Crack Propagation In Composite Patch Repairs Using Neural Networks, Navdeep Singh, Navrag Singh, Anthony Chukwujekwu Okafor
Mechanical and Aerospace Engineering Faculty Research & Creative Works
An aircraft is subjected to severe structural and aerodynamic loads during its service life. These loads can cause damage or weakening of the structure especially for aging military and civilian aircraft, thereby affecting its load carrying capabilities. Hence composite patch repairs are increasingly used to repair damaged aircraft metallic structures to restore its structural efficiency. This paper presents the results of Acoustic Emission (AE) monitoring of crack propagation in 2024-T3 Clad aluminum panels repaired with adhesively bonded octagonal, single sided boron/epoxy composite patch under tension-tension fatigue loading. Crack propagation gages were used to monitor crack initiation. The identified AE sensor …
Neural Network Controller Development And Implementation For Spark Ignition Engines With High Egr Levels, Jonathan B. Vance, Atmika Singh, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier
Neural Network Controller Development And Implementation For Spark Ignition Engines With High Egr Levels, Jonathan B. Vance, Atmika Singh, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier
Electrical and Computer Engineering Faculty Research & Creative Works
Past research has shown substantial reductions in the oxides of nitrogen (NOx) concentrations by using 10% -25% exhaust gas recirculation (EGR) in spark ignition (SI) engines (see Dudek and Sain, 1989). However, under high EGR levels, the engine exhibits strong cyclic dispersion in heat release which may lead to instability and unsatisfactory performance preventing commercial engines to operate with high EGR levels. A neural network (NN)-based output feedback controller is developed to reduce cyclic variation in the heat release under high levels of EGR even when the engine dynamics are unknown by using fuel as the control input. A separate …