Controls and Control Theory Commons^™

Magneto-Rheological Actuators For Human-Safe Robots: Modeling, Control, And Implementation, Peyman Yadmellat

Electronic Thesis and Dissertation Repository

In recent years, research on physical human-robot interaction has received considerable attention. Research on this subject has led to the study of new control and actuation mechanisms for robots in order to achieve intrinsic safety. Naturally, intrinsic safety is only achievable in kinematic structures that exhibit low output impedance. Existing solutions for reducing impedance are commonly obtained at the expense of reduced performance, or significant increase in mechanical complexity. Achieving high performance while guaranteeing safety seems to be a challenging goal that necessitates new actuation technologies in future generations of human-safe robots.

In this study, a novel two degrees-of-freedom safe …

On Sensorless Collision Detection And Measurement Of External Forces In Presence Of Modeling Inaccuracies, Vahid Sotoudehnejad

Electronic Thesis and Dissertation Repository

The field of human-robot interaction has garnered significant interest in the last decade. Every form of human-robot coexistence must guarantee the safety of the user. Safety in human-robot interaction is being vigorously studied, in areas such as collision avoidance, soft actuators, light-weight robots, computer vision techniques, soft tissue modeling, collision detection, etc. Despite the safety provisions, unwanted collisions can occur in case of system faults. In such cases, before post-collision strategies are triggered, it is imperative to effectively detect the collisions. Implementation of tactile sensors, vision systems, sonar and Lidar sensors, etc., allows for detection of collisions. However, due to …

Robust And Adaptive Attitude Control Of Spacecraft Using Solar Radiation Pressure, Lakshmi Srinivasan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Satellites in orbit are expected to maintain a preset attitude either pointing towards Earth (in case of satellites for weather) or pointing towards space for the purpose of research and exploration. The satellite as a system though is extremely nonlinear and the system parameters are not easily available. The goal of this thesis is to develop robust and adaptive control laws that can be used to control the attitude of satellites in elliptic orbits. The attitude of the satellite is controlled by the use of Solar Radiation Pressure (SRP) on the solar panels of the satellite. The SRP is basically …

A Hybrid Visual Control Scheme To Assist The Visually Impaired With Guided Reaching Tasks, Duane Jacques

Electronic Thesis and Dissertation Repository

In recent years, numerous researchers have been working towards adapting technology developed for robotic control to use in the creation of high-technology assistive devices for the visually impaired. These types of devices have been proven to help visually impaired people live with a greater degree of confidence and independence. However, most prior work has focused primarily on a single problem from mobile robotics, namely navigation in an unknown environment. In this work we address the issue of the design and performance of an assistive device application to aid the visually-impaired with a guided reaching task. The device follows an eye-in-hand, …

Control Studies Of Dfig Based Wind Power Systems, Zhiqiang Jin

Doctoral Dissertations

Wind energy as an outstanding and competitive form of renewable energy, has been growing fast worldwide in recent years because of its importance to reduce the pollutant emission generated by conventional thermal power plants and the rising prices and the unstable supplies of fossil-fuel. However, in the development of wind energy, there are still many ongoing challenges.

An important challenge is the need of voltage control to maintain the terminal voltage of a wind plant to make it a PV bus like conventional generators with excitation control. In the literature with PI controllers used, the parameters of PI controllers need …

Study Of Stability Analysis Of A Grid-Connected Doubly Fed Induction Generator (Dfig)-Based Small Wind Farm, Baishakhi Dhar

Electronic Thesis and Dissertation Repository

Wind is the most reliable, clean and fast-developing renewable energy source. The DFIG-based variable speed wind turbine system is now the most popular in wind power industry. With power being so in-demanding, a large wind farm needs to be developed to produce more power from a stable system. But before such a large wind farm is installed, better understanding is needed of the system’s intrinsic dynamic behavior, range of stability region and parametric effects on system stability. Hence, a small wind farm with two identical DFIG-based wind turbines connected to a grid network has been considered for this study.

A …

Three-Phase Reduced Switch Topologies For Ac-Dc Front-End And Single-Stage Converters, Dunisha Wijeratne

Electronic Thesis and Dissertation Repository

Conventional three-phase ac-dc converters have two converter stages. They have a front-end converter that converts the input ac voltage into an intermediate dc bus voltage and a second, back-end converter that converts this dc bus voltage into the desired isolated dc output voltage. The front-end converter also performs power factor correction (PFC) and shapes the three-phase input currents so that they are nearly sinusoidal and in phase with the three-phase input voltages. This allows the ac power source to be used in the most efficient manner.

The front-end ac-dc converter is typically implemented with six switches while the back-end dc-dc …

Design Of An Energy Efficient Virtual End Node Client Using Openadr2.0a And Smap, Kevin Navero

BioResource and Agricultural Engineering

Demand Response (DR) describes the set of actions taken to impose a reduction in electrical loads to stabilize the power grid and decrease costs. It is used when power grid emergencies or extremely high demand and congestion, threaten the electricity supply-demand balance. Automated Demand Response (ADR) describes a web-based control system that triggers DR events automatically by signaling other pre-programmed control systems. This project intends to use the OpenADR2.0 specifications provided by the OpenADR Alliance to construct an open source Virtual End Node (VEN) client to retrieve DR signals. The Simple Measurement and Actuation Profile (sMAP) software is also used …

Control System Infrastructure For The Cal Poly Human Powered Helicopter: Upturn Ii, Douglas A. Thornber, Samuel J. Wahyou

Aerospace Engineering

The Upturn was donated to Cal Poly in October 2012 by Neal Saiki from NTS. Our project was to replicate the old system to decrease the turn-around time in case of a crash during a test flight. The control system for the Upturn II was designed with the same considerations that were used for the Upturn. The result we got was inconclusive for the sensor selection, the new control system is heavier than the old system, and we couldn’t validate the system without doing a flight test. For the next iteration if some of the replication requirements are relaxed the …

Low-Cost Imu Implementation Via Sensor Fusion Algorithms In The Arduino Environment, Brandon Mccarron

Aerospace Engineering

A multi-phase experiment was conducted at Cal Poly in San Luis Obispo, CA, to design a low-cost inertial measurement unit composed of a 3-axis accelerometer and 3-axis gyroscope. Utilizing the growing microprocessor software environment, a 3-axis accelerometer and 3-axis gyroscope simulated 6 degrees of freedom orientation sensing through sensor fusion. By analyzing a simple complimentary filter and a more complex Kalman filter, the outputs of each sensor were combined and took advantage of the benefits of both sensors to improved results. Gyroscopic drift was removed in the pitch and roll axes using the Kalman filter for both static and dynamic …

Meat Smoker, Rhianna Topp

Electrical Engineering

This Senior Project consists of designing and building a meat smoker. The design of this meat smoker incorporates knowledge of control systems, programming, hardware, and materials manufacturing. This smoker is made to allow the user an easy experience of smoking food. The smoker provides the user with a programmable temperature and timer. It also has an automatic wood chip loader as deemed necessary to keep the correct amount of smoke distributed. Lastly, this smoker has an automatic application of the user’s choice of liquid to the meat. By designing a smoker with these capabilities, an untrained person desiring to smoke …

Control Law Calculation And Verification Methods For The Variable Stability Navion In-Flight Simulation Aircraft, Joe Ming Yin Siu

Masters Theses

The University of Tennessee Space Institute’s (UTSI) variable stability research aircraft, Ryan Navion N66UT, was extensively modified by the Princeton University in the 1960’s. When UTSI acquired the aircraft from Princeton, volumes of calibration data, charts, and schematics manuals were transferred to UTSI.

Based on the study and research of available Princeton documents, methods of calculating flight control laws were “reverse-engineered”. The Variable Stability Navion employs an implicit model following structure to achieve in-flight simulation of other aircraft’s flying quality. Mathematical formulas were derived to calculate stability derivative potentiometer settings, for the analog response feedback flight controls system. MATLAB scripts …

Voltage Stability Analysis Using Simulated Synchrophasor Measurements, Allan Agatep

Master's Theses

An increase in demand for electric power has forced utility transmission systems to continuously operate under stressed conditions, which are close to instability limits. Operating power systems under such conditions along with inadequate reactive power reserves initiates a sequence of voltage instability points and can ultimately lead to a system voltage collapse. Significant research have been focused on time-synchronized measurements of power systems which can be used to frequently determine the state of a power system and can lead to a more robust protection, control and operation performance. This thesis discusses the applicability of two voltage stability synchrophasor-based indices from …

Modeling And Analysis Of A Dynamic Voltage Regulator, Timothy David Haskell

Master's Theses

Increased government funding and incentives in recent years has led to an increase in the number of grid-tied renewable energy sources as their economic benefits become more renowned. Unfortunately, the outputs of these renewable resources are often highly variable, resulting in undesirable voltage disruptions that are harmful to sensitive loads. In addition to the energy variability of renewable energy sources, random voltage sags, swells and disruptions are already a major issue in power systems. Recent advances in power electronic devices have provided a platform for new solutions to the voltage support problem in power systems. One promising solution is the …

Rigid Body Attitude Estimation: An Overview And Comparative Study, Nojan Madinehi

Electronic Thesis and Dissertation Repository

The attitude estimation of rigid body systems has attracted the attention of many researchers over the years. The development of efficient estimation algorithms that can accurately estimate the orientation of a rigid body is a crucial step towards a reliable implementation of control schemes for underwater and flying vehicles.

The primary focus of this thesis consists in investigating various attitude estimation techniques and their applications.

Two major classes are discussed. The first class consists of the earliest static attitude determination techniques relying solely on a set of body vector measurements of known vectors in the inertial frame. The second class …

Firmware Counterfeiting And Modification Attacks On Programmable Logic Controllers, Zachary H. Basnight

Theses and Dissertations

Recent attacks on industrial control systems (ICSs), like the highly publicized Stuxnet malware, have perpetuated a race to the bottom where lower level attacks have a tactical advantage. Programmable logic controller (PLC) firmware, which provides a software-driven interface between system inputs and physically manifested outputs, is readily open to modification at the user level. Current efforts to protect against firmware attacks are hindered by a lack of prerequisite research regarding details of attack development and implementation. In order to obtain a more complete understanding of the threats posed by PLC firmware counterfeiting and the feasibility of such attacks, this research …

Emulation Of Industrial Control Field Device Protocols, Robert M. Jaromin

Theses and Dissertations

It has been shown that thousands of industrial control devices are exposed to the Internet, however, the extent and nature of attacks on such devices remains unknown. The first step to understanding security problems that face modern supervisory control and data acquisition (SCADA) and industrial controls networks is to understand the various attacks launched on Internet-connected field devices. This thesis describes the design and implementation of an industrial control emulator on a Gumstix single-board computer as a solution. This emulator acts as a decoy field device, or honeypot, intended to be probed and attacked via an Internet connection. Evaluation techniques …

Caddy: A 2005 Roborodentia Entry With Vision And Path Planning Abilities, Taylor Braun-Jones

Computer Engineering

Roborodentia is an autonomous robotics competition held each year during Cal Poly’s Open House. For the 2005 competition, robot entries needed to navigate a maze searching for three randomly placed golf balls, collect them, and then deposit the balls in the “nest” at the end of the maze. A newly added aspect for the 2005 competition included two bonus balls that were placed on a platform behind the wall in two predetermined corners of the maze.

Caddy is a robot that was entered into the 2005 Roborodentia competition. Caddy included a vision system that allowed searching for balls down untraveled …

A Dual-Rate Model Predictive Controller For Fieldbus Based Distributed Control Systems, Mohammad Arif Hossain

Electronic Thesis and Dissertation Repository

In modern Distributed Control Systems (DCS), an industrial computer network protocol known as fieldbus is used in chemical, petro-chemical and other process industries for real-time communication between digital controllers, sensors, actuators and other smart devices. In a closed-loop digital control system, data is transferred from sensor to controller and controller to actuator cyclically in a timely but discontinuous fashion at a specific rate known as sampling-rate or macrocycle through fieldbus. According to the current trend of fieldbus technology, in most industrial control systems, the sampling-rate or macrocycle is fixed at the time of system configuration. This fixed sampling-rate makes it …

The Modeling, Analysis And Control Of Resilient Manufacturing Enterprises, Yao Hu

Theses and Dissertations--Electrical and Computer Engineering

The resilience of manufacturing enterprises is an important research topic, since disruptions have severe effects on the normal operation of manufacturing enterprises, especially as manufacturing supply chains become global. Although many case studies have been carried out to address resilience in organizations, a systematic method to model and analyze the resilience dynamics in manufacturing enterprises is not well developed. This study is intended to conduct research on quantitative analysis and control for resilience.

After reviewing the literature addressing resilience, a modeling framework is presented to characterize the resilience of a manufacturing enterprise responding to disruptive events, which includes inventory ow …

Power Control Of Single-Stage Pv Inverter For Distribution System Volt-Var Optimization, Xiao Liu

Theses and Dissertations--Electrical and Computer Engineering

The output power variability of intermittent renewable sources can cause significant fluctuations in distribution system voltages. A local linear controller that exploits the capability of a photovoltaic inverter to provide both real and reactive power is described. This controller substitutes reactive power for real power when fluctuations in the output of the photovoltaic source are experienced. In this way, the inverter can help mitigate distribution system voltage fluctuations. In order to provide real and reactive to the grid, a three-phase grid-connected single-stage photovoltaic system with maximum power point tracking and power control is described. A method of reducing the current …

Geothermal Injection Well Monitoring, Timothy Rempher

Electrical Engineering

People depend on electricity all over the world. They depend on it for anything from drying their hair to global communications to heating up food. Many methods of power generation exist, each using a different fuel such as nuclear power, natural gas, coal, wind or the sun. This project focuses on a power plant which uses the naturally hot water in the ground to generate electricity. This process of generating power is called “Geothermal.” This project consists of two parts. The first and major part is the design logic of a PLC program that monitors the flow rate of an …

Decentralized Adaptive Control For Uncertain Linear Systems: Techniques With Local Full-State Feedback Or Local Relative-Degree-One Output Feedback, James D. Polston

Theses and Dissertations--Mechanical Engineering

This thesis presents decentralized model reference adaptive control techniques for systems with full-state feedback and systems with output feedback. The controllers are strictly decentralized, that is, each local controller uses feedback from only local subsystems and no information is shared between local controllers.

The full-state feedback decentralized controller is effective for multi-input systems, where the dynamics matrix and control-input matrix are unknown. The decentralized controller achieves asymptotic stabilization and command following in the presence of sinusoidal disturbances with known spectrum. We present a construction technique of the reference-model dynamics such that the decentralized controller is effective for systems with arbitrarily …

Neural Network Based Control Of Integrated Recycle Heat Exchanger Superheaters In Circulating Fluidized Bed Boilers, David D. Biruk

UNF Graduate Theses and Dissertations

The focus of this thesis is the development and implementation of a neural network model predictive controller to be used for controlling the integrated recycle heat exchanger (Intrex) in a 300MW circulating fluidized bed (CFB) boiler. Discussion of the development of the controller will include data collection and preprocessing, controller design and controller tuning. The controller will be programmed directly into the plant distributed control system (DCS) and does not require the continuous use of any third party software.

The intrexes serve as the loop seal in the CFB as well as intermediate and finishing superheaters. Heat is transferred to …

Visual Attitude Propagation For Small Satellites, Samir Ahmed Rawashdeh

Theses and Dissertations--Electrical and Computer Engineering

As electronics become smaller and more capable, it has become possible to conduct meaningful and sophisticated satellite missions in a small form factor. However, the capability of small satellites and the range of possible applications are limited by the capabilities of several technologies, including attitude determination and control systems. This dissertation evaluates the use of image-based visual attitude propagation as a compliment or alternative to other attitude determination technologies that are suitable for miniature satellites. The concept lies in using miniature cameras to track image features across frames and extracting the underlying rotation.

The problem of visual attitude propagation as …

Active Optimal Control Strategies For Increasing The Efficiency Of Photovoltaic Cells, Sharif Aljoaba

Theses and Dissertations--Electrical and Computer Engineering

Energy consumption has increased drastically during the last century. Currently, the worldwide energy consumption is about 17.4 TW and is predicted to reach 25 TW by 2035. Solar energy has emerged as one of the potential renewable energy sources. Since its first physical recognition in 1887 by Adams and Day till nowadays, research in solar energy is continuously developing. This has lead to many achievements and milestones that introduced it as one of the most reliable and sustainable energy sources. Recently, the International Energy Agency declared that solar energy is predicted to be one of the major electricity production energy …

An Attitude Determination System With Mems Gyroscope Drift Compensation For Small Satellites, Maxwell Bezold

Theses and Dissertations--Electrical and Computer Engineering

This thesis presents the design of an attitude determination system for small satellites that automatically corrects for attitude drift. Existing attitude determination systems suffer from attitude drift due to the integration of noisy rate gyro sensors used to measure the change in attitude. This attitude drift leads to a gradual loss in attitude knowledge, as error between the estimated attitude and the actual attitude increases.

In this thesis a Kalman filter is used to complete sensor fusion which combines sensor observations with a projected attitude based on the dynamics of the satellite. The system proposed in this thesis also utilizes …