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Integrated Guidance And Control Of Missiles With Θ-D Method, Ming Xin, S. N. Balakrishnan, Ernest J. Ohlmeyer Nov 2006

Integrated Guidance And Control Of Missiles With Θ-D Method, Ming Xin, S. N. Balakrishnan, Ernest J. Ohlmeyer

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A new suboptimal control method is proposed in this study to effectively design an integrated guidance and control system for missiles. Optimal formulations allow designers to bring together concerns about guidance law performance and autopilot responses under one unified framework. They lead to a natural integration of these different functions. by modifying the appropriate cost functions, different responses, control saturations (autopilot related), miss distance (guidance related), etc., which are of primary concern to a missile system designer, can be easily studied. A new suboptimal control method, called the θ-D method, is employed to obtain an approximate closed-form solution to this ...


Torque Ripple Sensor And Mitigation Mechanism, Jason Neely, Steven Pekarek, Jason M. Banaskavich, Daniel S. Stutts Oct 2006

Torque Ripple Sensor And Mitigation Mechanism, Jason Neely, Steven Pekarek, Jason M. Banaskavich, Daniel S. Stutts

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A torque ripple sensor and method for torque ripple sensing and/or mitigation. A piezoelectric sensor is positioned relative to a motor so that torque fluctuations due to torque ripple of the motor are transmitted to the sensor, resulting in strain of a piezoelectric element. A resulting signal can be amplified and conditioned for determining a magnitude of the torque ripple and/or fed into a feedback loop for applying current control or a counter-torque to the motor for torque ripple mitigation.


Internal Small Volume Storage Water Heater, Kelly Homan Oct 2006

Internal Small Volume Storage Water Heater, Kelly Homan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The invention concerns devices for water storage, heating and delivery. A storage water heater of the invention provides an amount of unmixed recently heated water from an internal small volume during a draw along with water from a main volume. When water is drawn from the storage water heater, an amount of recently heated water substantially unmixed with the remaining volume of the tank is drawn along with heated water from the remaining volume. Substantial performance increases in the hot water that may be delivered over a period, such as an hour, may be achieved compared to an otherwise identical ...


Comparison Of Thermal Properties Of Laser Deposition And Traditional Welding Process Via Thermal Diffusivity Measurement, Yu Yang, Omoghene Osaze Obahor, Yaxin Bao, Todd E. Sparks, Jianzhong Ruan, Jacquelyn K. Stroble, Robert G. Landers, Joseph William Newkirk, Frank W. Liou Aug 2006

Comparison Of Thermal Properties Of Laser Deposition And Traditional Welding Process Via Thermal Diffusivity Measurement, Yu Yang, Omoghene Osaze Obahor, Yaxin Bao, Todd E. Sparks, Jianzhong Ruan, Jacquelyn K. Stroble, Robert G. Landers, Joseph William Newkirk, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laser deposition is an effective process for mold and die repair. In order to improve the part repair quality, the process impact on thermal diffusivity and thermal conductivity needs to be understood for laser deposited, welded and virgin H13. In this paper, H13 tool steel samples were made by laser deposition, welding and virgin H13 and then cut into pieces. Experiments were conducted to investigate the thermal diffusivity and conductivity. A laser flash method is used to test these samples. The future work and opportunities are also summarized.


Effects Of Current On Droplet Generation And Arc Plasma In Gas Metal Arc Welding, J. Hu, Hai-Lung Tsai Jan 2006

Effects Of Current On Droplet Generation And Arc Plasma In Gas Metal Arc Welding, J. Hu, Hai-Lung Tsai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In gas metal arc welding (GMAW), a technology using pulsed currents has been employed to achieve the one-droplet-per-pulse (ODPP) metal transfer mode with the advantages of low average currents, a stable and controllable droplet generation, and reduced spatter. In this paper, a comprehensive model was developed to study the effects of different current profiles on the droplet formation, plasma generation, metal transfer, and weld pool dynamics in GMAW. Five types of welding currents were studied, including two constant currents and three wave form currents. In each type, the transient temperature and velocity distributions of the arc plasma and the molten ...


Robust/Optimal Temperature Profile Control Using Neural Networks, Vivek Yadav, Radhakant Padhi, S. N. Balakrishnan Jan 2006

Robust/Optimal Temperature Profile Control Using Neural Networks, Vivek Yadav, Radhakant Padhi, S. N. Balakrishnan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An approximate dynamic programming (ADP) based neurocontroller is developed for a heat transfer application. Heat transfer problem for a fin in a car''s electronic module is modeled as a nonlinear distributed parameter (infinite-dimensional) system by taking into account heat loss and generation due to conduction, convection and radiation. A low-order, finite-dimensional lumped parameter model for this problem is obtained by using Galerkin projection and basis functions designed through the `Proper Orthogonal Decomposition'' technique (POD) and the `snap-shot'' solutions. A suboptimal neurocontroller is obtained with a single-network-adaptivecritic (SNAC). Further contribution of this paper is to develop an online robust controller ...


Analysis Of Damage In Laminated Automotive Glazing Subjected To Simulated Head Impact, Shuangmei Zhao, Li Chai, S. D. Barbat, Lokeswarappa R. Dharani Jan 2006

Analysis Of Damage In Laminated Automotive Glazing Subjected To Simulated Head Impact, Shuangmei Zhao, Li Chai, S. D. Barbat, Lokeswarappa R. Dharani

Mechanical and Aerospace Engineering Faculty Research & Creative Works

During vehicle accidents, occupant's head impacting on windshield or side window is commonly observed. Any attempt to design glazing that minimizes injury to and death of occupants during a vehicle accident requires a thorough understanding of the mechanical behavior of automotive glazing subjected to head impact loads. A continuum damage mechanics (CDM) based constitutive model is developed and implemented into an axisymmetric finite element model to study the failure and impact resistance of laminated automotive glazing subjected to simulated head impact. An anisotropic elastic damage tensor with a linear damage evolution law is chosen to model the failure of ...


An Optimal Dynamic Inversion Approach For Controlling A Class Of One-Dimensional Nonlinear Distributed Parameter Systems, Radhakant Padhi, S. N. Balakrishnan Jan 2006

An Optimal Dynamic Inversion Approach For Controlling A Class Of One-Dimensional Nonlinear Distributed Parameter Systems, Radhakant Padhi, S. N. Balakrishnan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Combining the principles of dynamic inversion and optimization theory, a new approach is presented for stable control of a class of one-dimensional nonlinear distributed parameter systems, assuming the availability a continuous actuator in the spatial domain. Unlike the existing approximate-then-design and design-then-approximate techniques, here there is no need of any approximation either of the system dynamics or of the resulting controller. Rather, the control synthesis approach is fairly straight-forward and simple. The controller formulation has more elegance because we can prove the convergence of the controller to its steady state value. To demonstrate the potential of the proposed technique, a ...


Creating Cross-Over Vehicles: Defining And Combining Vehicle Classes Using Shape Grammars, Seth D. Orsborn, R. Pawlicki, R. Smith, Jonathan Cagan Jan 2006

Creating Cross-Over Vehicles: Defining And Combining Vehicle Classes Using Shape Grammars, Seth D. Orsborn, R. Pawlicki, R. Smith, Jonathan Cagan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In the push for new vehicle designs, the distinctions between vehicle classes are quickly becoming blurred. We use shape grammars to quantify the differences between vehicle classes through the application of class-specific rules and the constraint of rule applications to within parametric ranges determined for each class. This allows for the development of new vehicle forms that clearly fall within a class or purposefully cross over the boundaries of classes and mix rules and ranges to create unique and interesting cross-over vehicles.


An Internet Based Intelligent Argumentation System For Collaborative Engineering Design, Xiaoqing Frank Liu, Samir Raorane, Man Zheng, Ming-Chuan Leu Jan 2006

An Internet Based Intelligent Argumentation System For Collaborative Engineering Design, Xiaoqing Frank Liu, Samir Raorane, Man Zheng, Ming-Chuan Leu

Computer Science Faculty Research & Creative Works

Modern product design is a very complicated process which involves groups of designers, manufacturers, suppliers, and customer representatives. Conflicts are unavoidable in collaboration among multiple stakeholders, who have different objectives, requirements, and priorities. Unfortunately, current web-based collaborative engineering design systems do not support collaborative conflict resolution. In this paper, we will develop an intelligent computational argumentation model to enable management of a large scale argumentation network, and resolution of conflicts based on argumentation from many participants. A web-based intelligent argumentation tool is developed as a part of a web-based collaborative engineering design system based on the above model to resolve ...


Neural Network-Based Output Feedback Controller For Lean Operation Of Spark Ignition Engines, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier, Jonathan B. Vance, Pingan He Jan 2006

Neural Network-Based Output Feedback Controller For Lean Operation Of Spark Ignition Engines, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier, Jonathan B. Vance, Pingan He

Electrical and Computer Engineering Faculty Research & Creative Works

Spark ignition (SI) engines running at very lean conditions demonstrate significant nonlinear behavior by exhibiting cycle-to-cycle dispersion of heat release even though such operation can significantly reduce NOx emissions and improve fuel efficiency by as much as 5-10%. A suite of neural network (NN) controller without and with reinforcement learning employing output feedback has shown ability to reduce the nonlinear cyclic dispersion observed under lean operating conditions. The neural network controllers consists of three NN: a) A NN observer to estimate the states of the engine such as total fuel and air; b) a second NN for generating virtual input ...


Dynamic Re-Optimization Of A Spacecraft Attitude Controller In The Presence Of Uncertainties, Nishant Unnikrishnan, S. N. Balakrishnan, Radhakant Padhi Jan 2006

Dynamic Re-Optimization Of A Spacecraft Attitude Controller In The Presence Of Uncertainties, Nishant Unnikrishnan, S. N. Balakrishnan, Radhakant Padhi

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Online trained neural networks have become popular in recent years in the design of robust and adaptive controllers for dynamic systems with uncertainties due to their universal function approximation capabilities. This paper discusses a technique that dynamically reoptimizes a Single Network Adaptive Critic (SNAC) based optimal controller in the presence of unmodeled plant uncertainties. The SNAC based optimal controller designed for the nominal plant model no more retains optimality in the presence of uncertainties/unmodeled dynamics that may creep up in the system equations during operation. This calls for a strategy to re-optimize the existing SNAC controller with respect to ...


Optimal Impulse Control Of Systems With Control Constraints And Application To Hiv Treatment, Vivek Yadav, S. N. Balakrishnan Jan 2006

Optimal Impulse Control Of Systems With Control Constraints And Application To Hiv Treatment, Vivek Yadav, S. N. Balakrishnan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this paper, conditions for optimal impulse control of an impulsive system with constraints on control are derived. These hold for a system whose states can be changed instantaneously at discrete times with impulses while a continuous control is being applied between those times. The conditions derived are applied to the problem of optimal HIV treatment. Simulation results are presented to show the treatment procedure. The results obtained show that the intervention method developed leads to good results.


Optimal Management Of Beaver Population Using A Reduced-Order Distributed Parameter Model And Single Network Adaptive Critics, Radhakant Padhi, S. N. Balakrishnan Jan 2006

Optimal Management Of Beaver Population Using A Reduced-Order Distributed Parameter Model And Single Network Adaptive Critics, Radhakant Padhi, S. N. Balakrishnan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Beavers are often found to be in conflict with human interests by creating nuisances like building dams on flowing water (leading to flooding), blocking irrigation canals, cutting down timbers, etc. At the same time they contribute to raising water tables, increased vegetation, etc. Consequently, maintaining an optimal beaver population is beneficial. Because of their diffusion externality (due to migratory nature), strategies based on lumped parameter models are often ineffective. Using a distributed parameter model for beaver population that accounts for their spatial and temporal behavior, an optimal control (trapping) strategy is presented in this paper that leads to a desired ...


Statistically Steady Measurements Of Rayleigh-Taylor Mixing In A Gas Channel, Malcolm J. Andrews, Arindam Banerjee Jan 2006

Statistically Steady Measurements Of Rayleigh-Taylor Mixing In A Gas Channel, Malcolm J. Andrews, Arindam Banerjee

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A novel gas channel experiment is described to study the development of high Atwood number Rayleigh-Taylor mixing. Two gas streams, one containing air and the other containing a helium-air mixture, flow parallel to each other separated by a thin splitter plate. The streams meet at the end of a splitter plate leading to the formation of an unstable interface and of buoyancy driven mixing. This buoyancy driven mixing experiment allows for long data collection times, has short transients, and is statistically steady. The facility was designed to be capable of large Atwood number studies (At~0.75). We describe initial ...


A Non-Intrusive Polynomial Chaos Method For Uncertainty Propagation In Cfd Simulations, Serhat Hosder, R. Perez, Robert W. Walters Jan 2006

A Non-Intrusive Polynomial Chaos Method For Uncertainty Propagation In Cfd Simulations, Serhat Hosder, R. Perez, Robert W. Walters

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An inexpensive non-intrusive polynomial chaos (NIPC) method for the propagation of input uncertainty in CFD simulations is presented. The method is straightforward to implement for any stochastic fluid dynamics problem and computationally less expensive than sampling or quadrature based non-intrusive methods. To validate the present NIPC approach, the method has been applied to: (1) an inviscid oblique shock wave problem with geometric uncertainty, (2) an inviscid expansion wave problem with geometric uncertainty, and (3) a subsonic, two-dimensional, laminar boundary layer flow over a flat plate with an uncertain free-stream dynamic viscosity. For all test cases, the statistics (mean and the ...


Regulation Of Powder Mass Flow Rate In Gravity-Fed Powder Feeder Systems, Vishnu Thayalan, Robert G. Landers Jan 2006

Regulation Of Powder Mass Flow Rate In Gravity-Fed Powder Feeder Systems, Vishnu Thayalan, Robert G. Landers

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Precise regulation of powder mass flow in laser-based manufacturing processes is critical to achieving excellent part dimensional and microstructure quality. Control of powder mass flow is challenging because low flow rates, where nonlinear effects are significant, are typically required. Also, gravity-fed powder feeder systems have significant material transport delays, making the control of powder mass flow even more challenging. This paper presents a control strategy for regulating the powder mass flow rate in a gravity-fed powder feeder system. A dynamic model of the powder feeder system, including material transport delay, is constructed, and a modified proportional plus integral (PI) controller ...


Magnetically Filtered Faraday Probe For Measuring The Ion Current Density Profile Of A Hall Thruster., Joshua L. Rovey, Mitchell L. R. Walker, Alec D. Gallimore, Peter Y. Peterson Jan 2006

Magnetically Filtered Faraday Probe For Measuring The Ion Current Density Profile Of A Hall Thruster., Joshua L. Rovey, Mitchell L. R. Walker, Alec D. Gallimore, Peter Y. Peterson

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The ability of a magnetically filtered Faraday probe (MFFP) to obtain the ion current density profile of a Hall thruster is investigated. The MFFP is designed to eliminate the collection of low-energy, charge-exchange (CEX) ions by using a variable magnetic field as an ion filter. In this study, a MFFP, Faraday probe with a reduced acceptance angle (BFP), and nude Faraday probe are used to measure the ion current density profile of a 5 kW Hall thruster operating over the range of 300-500 V and 5-10 mg/s. The probes are evaluated on a xenon propellant Hall thruster in the ...


Plasma Modeling For Ultrashort Laser Ablation Of Dielectrics, Lan Jiang, Hai-Lung Tsai Jan 2006

Plasma Modeling For Ultrashort Laser Ablation Of Dielectrics, Lan Jiang, Hai-Lung Tsai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In ultrashort pulse (<10 ps) laser ablation of dielectrics, affected materials are first transformed into absorbing plasma with metallic properties and, then, the subsequent laser-plasma interaction causes material removals. For ultrashort-pulse laser ablation of dielectrics, this study proposes a model using the Fokker-Planck equation for electron density distribution, a plasma model for the optical properties of ionized dielectrics, and quantum treatments for electron heating and relaxation time. The free electron density distribution of the plasma within the pulse duration is then used to determine the ablation crater shape. The predicted threshold fluences and ablation depths for barium aluminum borosilicate and fused silica are in agreement with published experimental data. It is found that the significantly varying optical properties in time and space are the key factors determining the ablation crater shape. The effects of fluence and pulse duration are also studied.


Automation Of Hybrid Manufacturing System Through Tight Integration Of Software And Sensor Feedback, Robert G. Landers, Frank W. Liou, Jacquelyn K. Stroble Jan 2006

Automation Of Hybrid Manufacturing System Through Tight Integration Of Software And Sensor Feedback, Robert G. Landers, Frank W. Liou, Jacquelyn K. Stroble

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper presents a framework for the automation of the Laser Aided Manufacturing Process (LAMP) lab at the University of Missouri-Rolla. The groundwork for the proposed system involves the integration of the LabVIEW software package and a PXI-8195 real time controller with several sensors and actuators. The incorporation of all key control parameters into one virtual instrument will help achieve the goal of an automated hybrid system. To achieve this goal, a five-phase plan, which will be further discussed in the paper, has been developed. The first phase of this plan, which includes the deposition of a thin walled structure ...


Experimental Simulation Of Lightning Optical Emissions In Clouds, Anil Ogale, Kunal Mitra, Arindam Banerjee Jan 2006

Experimental Simulation Of Lightning Optical Emissions In Clouds, Anil Ogale, Kunal Mitra, Arindam Banerjee

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The objective of the study is to experimentally determine the information content of lightning optical emissions through clouds. Clouds affect the amplitude of lightning signals and the apparent dimensions of the optical source. Multiple scattering from the cloud media also alters the shape of the temporal profile of the lightning signal. The goal is to provide accurate estimates of the arrival time delay and temporal pulse width broadening of output signals emitted from clouds for different cloud and lightning parameters. Experiments conducted in the laboratory yield a temporally broadened pulse with an overall decrease in the peak and a delay ...


Neural Network Approach For Obstacle Avoidance In 3-D Environments For Uavs, Vivek Yadav, Xiaohua Wang, S. N. Balakrishnan Jan 2006

Neural Network Approach For Obstacle Avoidance In 3-D Environments For Uavs, Vivek Yadav, Xiaohua Wang, S. N. Balakrishnan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this paper a controller design is proposed to get obstacle free trajectories in a three dimensional urban environment for unmanned air vehicles (UAVs). The controller has a two-layer architecture. In the upper layer, vision-inspired Grossberg neural network is proposed to get the shortest distance paths. In the bottom layer, a model predictive control (MPC) based controller is used to obtain dynamically feasible trajectories. Simulation results are presented for to demonstrate the potential of the approach.


Nonlinear Control Concepts For A Ua, Vijayakumar Janardhan, Derek Schmitz, S. N. Balakrishnan Jan 2006

Nonlinear Control Concepts For A Ua, Vijayakumar Janardhan, Derek Schmitz, S. N. Balakrishnan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A reconfigurable flight control method is developed to be implemented on an Unmanned Aircraft (UA), a thirty percent scale model of the Cessna 150. This paper presents the details of the UA platform, system identification, reconfigurable controller design, development, and implementation on the UA to analyze the performance metrics. A Crossbow Inertial Measurement Unit provides the roll, pitch, and yaw accelerations and rates along with the roll and pitch. The 100-400 mini-air data boom from SpaceAge Control provides the airspeed, altitude, angle of attack, and the side slip angles. System identification is accomplished by commanding preprogrammed inputs to the control ...


Neuroadaptive Model Following Controller Design For A Nonaffine Uav Model, Nishant Unnikrishnan, S. N. Balakrishnan Jan 2006

Neuroadaptive Model Following Controller Design For A Nonaffine Uav Model, Nishant Unnikrishnan, S. N. Balakrishnan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper proposes a new model-following adaptive control design technique for nonlinear systems that are nonaffine in control. The adaptive controller uses online neural networks that guarantee tracking in the presence of unmodeled dynamics and/or parameter uncertainties present in the system model through an online control adaptation procedure. The controller design is carried out in two steps: (i) synthesis of a set of neural networks which capture the unmodeled (neglected) dynamics or model uncertainties due to parametric variations and (ii) synthesis of a controller that drives the state of the actual plant to that of a reference model. This ...


Neural Network Control Of Spark Ignition Engines With High Egr Levels, A. Singh, Brian C. Kaul, J. A. Drallmeier, Jagannathan Sarangapani, Jonathan B. Vance Jan 2006

Neural Network Control Of Spark Ignition Engines With High Egr Levels, A. Singh, Brian C. Kaul, J. A. Drallmeier, Jagannathan Sarangapani, Jonathan B. Vance

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Research has shown substantial reductions in the oxides of nitrogen (NOx) concentrations by using 10% to 25% exhaust gas recirculation (EGR) in spark ignition (SI) engines [1]. However under high EGR levels the engine exhibits strong cyclic dispersion in heat release which may lead to instability and unsatisfactory performance. A suite of neural network (NN)-based output feedback controllers with and without reinforcement learning is developed to control the SI engine at high levels of EGR even when the engine dynamics are unknown by using fuel as the control input. A separate control loop was designed for controlling EGR levels ...