Engineering Commons^™

Flatness-Based Control Methodologies To Improve Frequency Regulation In Power Systems With High Penetration Of Wind, Maryam Hassani Variani

Doctoral Dissertations

To allow for high penetration of distributed generation and alternative energy units, it is critical to minimize the complexity of generator controls and to minimize the need for close coordination across regions. We propose that existing controls be replaced by a two-tier structure of local control operating within a global context of situational awareness. Flatness as an extension of controllability for non-linear systems is a key to enabling planning and optimization at various levels of the grid in this structure. In this study, flatness-based control for: one, Automatic Generation Control (AGC) of a multi-machine system including conventional generators; and two, …

Exact Controllability Of The Lazer-Mckenna Suspension Bridge Equation, Lanxuan Yu

UNLV Theses, Dissertations, Professional Papers, and Capstones

It is well known that suspension bridges may display certain oscillations under external aerodynamic forces. Since the collapse of the Tacoma Narrows suspension bridge in 1940, suspension bridge models have been studied by many researchers. Based upon the fundamental nonlinearity in suspension bridges that the stays connecting the supporting cables and the roadbed resist expansion, but do not resist compression, new models describing oscillations in suspension bridges have been developed by Lazer and McKenna [Lazer and McKenna (1990)]. Except for a paper by Leiva [Leiva (2005)], there have been very few work on controls of the Lazer-McKenna suspension bridge models …

Ubot-7: The Design Of A Compliant Dexterous Mobile Manipulator, Jonathan Cummings

Masters Theses

This thesis presents the design of uBot-7, the latest version of a dexterous mobile manipulator. This platform has been iteratively developed to realize a high performance-to-cost dexterous whole body manipulator with respect to mobile manipulation. The semi-anthropomorphic design of the uBot is a demonstrated and functional research platform for developing advanced autonomous perception, manipulation, and mobility tasks. The goal of this work is to improve the uBot’s ability to sense and interact with its environment in order to increase the platforms capability to operate dexterously, through the incorporation of joint torque feedback, and safely, through the implementation of passive and …

Joint Architecture For Reusable Vehicle-Integrated Software (J.A.R.V.I.S), Anthony Mark Kane

Open Access Theses

An integrated software architecture for development of unmanned research vehicles is developed. It has been created under the premise that all unmanned vehicles require a core set of functionality that is common across platforms and that priority should be to the readability and reusability of the code base. The architecture defines the top-level system interfaces allowing internal algorithms to be manipulated without affecting the rest of the system. A robust aerospace toolbox has been developed that provides a means to rapidly prototype algorithms without the need of recreating commonly used functions or the use of expensive, proprietary software.

Control Of A Spacecraft Using Mixed Momentum Exchange Devices, Blake J. Currie

Master's Theses

Hardware configurations, a control law, and a steering law are developed for a mixed hardware spacecraft that uses both control moment gyros and reaction wheels. Replacing one or more gyros in a spacecraft with a reaction wheel has potential for cost savings while still achieving much greater performance than using reaction wheels alone. Several simulated tests are run to compare the performance to a traditional all reaction wheel or all control moment gyro spacecraft, including analysis of failure modes and singular configurations. The mixed system performed similarly to all gyro systems, responding within 6% of the gyro system’s time for …

Interpreting, Stephanie Jo Kent

Doctoral Dissertations

What do community interpreting for the Deaf in western societies, conference interpreting for the European Parliament, and language brokering in international management have in common? Academic research and professional training have historically emphasized the linguistic and cognitive challenges of interpreting, neglecting or ignoring the social aspects that structure communication. All forms of interpreting are inherently social; they involve relationships among at least three people and two languages. The contexts explored here, American Sign Language/English interpreting and spoken language interpreting within the European Parliament, show that simultaneous interpreting involves attitudes, norms and values about intercultural communication that overemphasize information and discount …

Feedback Speed Control Of A Small Two-Stroke Internal Combustion Engine That Propels An Unmanned Aerial Vehicle, Paul D. Fjare

UNLV Theses, Dissertations, Professional Papers, and Capstones

Unmanned aerial vehicles (UAV) require intelligent control of their power source. Small UAV are typically powered by electric motors or small two-stroke internal combustion (IC) engines. Small IC engines allow for longer flight times but are more difficult to control and cause significant ground noise. A hybrid operation that uses the engine at high altitudes and the electric motors at low altitudes is desired. This would allow for extended flight with acceptable ground noise levels. Since the engine can not be restarted in the air it must be able to remain at idle for an extended time without stalling. A …

Laboratory Apparatus For Gas Turbine Combustion Development, Dustin Lee Cruise

Open Access Theses

The next generation of combustor technology will be required to meet the demands of a world more focused on greenhouse gases and global warming. Due to this new focus on emission control, combustors must produce less NO x , while operating in a higher pressure environment that is more prone to combustion instabilities.

This work focuses on the development of a lab and combustor that will be used for the next generation combustor development. The lab development includes layout and organization, facilities, measurement and instrumentation, automation of the testing process, and an imaging tool for diagnostics.

A Lean Direction Injection …

The Effect Of Learning And Cost Optimization On Line Of Balance Scheduling, Kareem Essam Zahran

Theses and Dissertations

The increase in populations throughout the past years introduced the need for improving and increasing countries’ infrastructure. Moreover, there has been an increasing demand for dwelling units ranging from small economic housing blocks to high-rise buildings and residential villa compounds. These projects are known by their repetitive nature, where a constant unit is repeated several times. Scheduling techniques that consider the learning effect as an influencing parameter in calculating productivity rates can improve the effectiveness of the scheduling process. This achieves more realistic forecasts resulting in optimum utilization of resources and better control during implementation phases. Linear scheduling techniques are …

Grid-Scale Energy Storage: A Proposed Control Algorithm For Sodium Sulfur Batteries, Daniel Spaizman

Master's Theses

With carbon dioxide levels in our atmosphere reaching record highs and 2020 quickly approaching, California is expected to pave the way for the United States in terms of replacing fossil fuel generation facilities with various renewable energy power plants. It is well documented that the inherent variability and limited duty cycle of renewables has hindered their growth. Energy storage technologies represent the bridge that can help us cross the divide from where we stand to where we must stand in the next 6 years. Utility companies value services such as peak shaving, voltage support, and frequency regulation, all of which …

Modification Of The Cal Poly Spacecraft Simulator System For Robust Control Law Verification, Tomoyuki Kato

Master's Theses

The Cal Poly Spacecraft Dynamics Simulator, also known as the Pyramidal Reaction Wheel Platform (PRWP), is an air-bearing four reaction wheel spacecraft simulator designed to simulate the low-gravity, frictionless condition of the space environment and to test and validate spacecraft attitude control hardware and control laws through real-time motion tests. The PRWP system was modified to the new Mk.III configuration, which adopted the MATLAB xPC kernel for better real-time hardware control. Also the Litton LN-200 IMU was integrated onto the PRWP and replaced the previous attitude sensor. Through the comparison of various control laws through motion tests the Mk.III configuration …

Kinesthetic Haptics Sensing And Discovery With Bilateral Teleoperation Systems, Tian Qiu

Doctoral Dissertations

In the mechanical engineering field of robotics, bilateral teleoperation is a classic but still increasing research topic. In bilateral teleoperation, a human operator moves the master manipulator, and a slave manipulator is controlled to follow the motion of the master in a remote, potentially hostile environment. This dissertation focuses on kinesthetic perception analysis in teleoperation systems. Design of the controllers of the systems is studied as the influential factor of this issue. The controllers that can provide different force tracking capability are compared using the same experimental protocol. A 6 DOF teleoperation system is configured as the system testbed. An …

Modeling, Analysis, And Control Of A Mobile Robot For In Vivo Fluoroscopy Of Human Joints During Natural Movements, Matthew A. Young

Doctoral Dissertations

In this dissertation, the modeling, analysis and control of a multi-degree of freedom (mdof) robotic fluoroscope was investigated. A prototype robotic fluoroscope exists, and consists of a 3 dof mobile platform with two 2 dof Cartesian manipulators mounted symmetrically on opposite sides of the platform. One Cartesian manipulator positions the x-ray generator and the other Cartesian manipulator positions the x-ray imaging device. The robotic fluoroscope is used to x-ray skeletal joints of interest of human subjects performing natural movement activities. In order to collect the data, the Cartesian manipulators must keep the x-ray generation and imaging devices accurately aligned while …

Control Of Grid-Connected Photovoltaic Systems Using Fractional Order Operators, Hadi Malek

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This work presents a new peak seeking strategy for maximum power point operation using fractional order operators in the three-phase grid-connected photovoltaic systems. Moreover, fractional order controllers have been implemented in the voltage and current control loops. The simulation results and theoretical analysis indicate that the proposed fractional order control strategy improves the efficiency of the system by reducing the total harmonic distortion of the injected current to the grid and increases the robustness of the system against uncertainties. Additionally, the proposed maximum power point tracking algorithms provide more robustness and faster convergence speed under environmental variations than other maximum …

An Efficiency-Motivated Attack Against Vehicles In A Platoon: Local Vehicle Control, Platoon Control Strategies, And Drive Train Technologies Considerations, David A. Cornelio Sosa

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Automated Electric Transportation Group (AET) at Utah State University proposes to demonstrate the benefits and feasibility of vehicle platooning. A platoon is a transportation system, formed by vehicles that are controlled automatically by computers (the driver does not operate the vehicle while cruising). Platoons are interesting in view of the future because they present many advantages: increase highway capacity and safety, reduce travel time, save energy, and reduce stress for human drivers. There are many problems to solve in order to make vehicle platooning a reality. In this work, the focus is not on making it feasible, but rather …

Optimal Control Of Energy Efficient Buildings, Cale David Nelson

Masters Theses

The building sector consumes a large part of the energy used in the United States and is responsible for nearly 40% of greenhouse gas emissions. Therefore, it is economically and environmentally important to reduce the building energy consumption to realize massive energy savings. Commercial buildings are complex, multi-physics, and highly stochastic dynamic systems. Recent work has focused on integrating modern modeling, simulation, and control techniques to solving this challenging problem. The overall focus of this thesis is directed toward designing an energy efficient building by controlling room temperature. One approach is based on a distributed parameter model represented by a …

Control Of Wind Energy Conversion Systems For Large-Scale Integration With The Power System, Omid Alizadeh

Electronic Thesis and Dissertation Repository

This thesis is mainly focused on (i) mathematical modeling and real power control of a direct-drive wind energy conversion system (WECS) that employs a high-pole permanent-magnet synchronous generator (PMSG), and (ii) the contribution of the WECS to the frequency regulation process in a host power system. In the first part, a strategy is proposed for real power control of the WECS, which augments the maximum power-point tracking (MPPT) feature of modern WECSs. The proposed strategy is based on rapid torque control, rather than the (slow) pitch-angle control. Moreover, a supplementary damping scheme is presented and tuned for the proposed power …

Multidimensional Optimal Droop Control For Wind Resources In Dc Microgrids, Kaitlyn J. Bunker

Dissertations, Master's Theses and Master's Reports - Open

Two important and upcoming technologies, microgrids and electricity generation from wind resources, are increasingly being combined. Various control strategies can be implemented, and droop control provides a simple option without requiring communication between microgrid components. Eliminating the single source of potential failure around the communication system is especially important in remote, islanded microgrids, which are considered in this work. However, traditional droop control does not allow the microgrid to utilize much of the power available from the wind. This dissertation presents a novel droop control strategy, which implements a droop surface in higher dimension than the traditional strategy. The droop …

Thermal And Cooling Systems Modeling Of Powertrain For A Plug -In Parallel-Through-The-Road Hybrid Electric Vehicle, Mengjia Cao

Wayne State University Theses

Thermal modeling and control play an ever increasing role with hybrid electric vehicle (HEV) design and development for improving overall vehicle energy efficiency, and to account for additional thermal loading from electric powertrain components such as electric motor, motor controller and battery pack.

This thesis presents a complete development process for an efficient modeling approach with integrated control strategy for the thermal management of plug-in HEV in a parallel-through-the road (PTTR) architecture, adopted by Wayne State University Hybrid Warriors for their Department of Energy's EcoCAR2 Plugging in to the Future Competition.

The frameworks of this project include simulating the thermal …

Parameter Identification And Fault Detection For Reliable Control Of Permanent Magnet Motors, Dusan Vukosav Progovac

Wayne State University Dissertations

The objective of this dissertation is to develop new fault detection, identification, estimation and control algorithms that will be used to detect winding stator fault, identify the motor parameters and optimally control machine during faulty condition. Quality or proposed algorithms for Fault detection, parameter identification and control under faulty condition will validated through analytical study (Cramer-Rao bound) and simulation. Simulation will be performed for three most applied control schemes: Proportional-Integral-Derivative (PID), Direct Torque Control (DTC) and Field Oriented Control (FOC) for Permanent Magnet Machines. New detection schemes forfault detection, isolation and machine parameter identification are presented and analyzed. Different control …

Development Of An Optical Sensor For Real-Time Weed Detection Using Laser Based Spectroscopy, Arie Jacobus Paap

Theses: Doctorates and Masters

The management of weeds in agriculture is a time consuming and expensive activity, including in Australia where the predominant strategy is blanket spraying of herbicides. This approach wastes herbicide by applying it in areas where there are no weeds. Discrimination of different plant species can be performed based on the spectral reflectance of the leaves. This thesis describes the development of a sensor for automatic spot spraying of weeds within crop rows. The sensor records the relative intensity of reflected light in three narrow wavebands using lasers as an illumination source.

A prototype weed sensor which had been previously developed …