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Controls and Control Theory Commons

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2008

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Articles 1 - 12 of 12

Full-Text Articles in Controls and Control Theory

Modeling And Stability Analysis Of Nonlinear Sampled-Data Systems With Embedded Recovery Algorithms, Heber Herencia-Zapana Oct 2008

Modeling And Stability Analysis Of Nonlinear Sampled-Data Systems With Embedded Recovery Algorithms, Heber Herencia-Zapana

Electrical & Computer Engineering Theses & Dissertations

Computer control systems for safety critical systems are designed to be fault tolerant and reliable, however, soft errors triggered by harsh environments can affect the performance of these control systems. The soft errors of interest which occur randomly, are nondestructive and introduce a failure that lasts a random duration. To minimize the effect of these errors, safety critical systems with error recovery mechanisms are being investigated. The main goals of this dissertation are to develop modeling and analysis tools for sampled-data control systems that are implemented with such error recovery mechanisms. First, the mathematical model and the well-posedness of the …


A Two-Degree-Of-Freedom Time-Optimal Solution For Hard Disk Drive Servo Problems, Shaohua Hu, Zhiqiang Gao May 2008

A Two-Degree-Of-Freedom Time-Optimal Solution For Hard Disk Drive Servo Problems, Shaohua Hu, Zhiqiang Gao

Electrical and Computer Engineering Faculty Publications

This paper deals with the hard disk drive (HDD) servo problems. A novel discrete time-optimal control solution is proposed in a two-degree-of-freedom (2DOF) structure, employing both the feedback and feedforward controllers. The time-optimal feedback controller, derived from a simple, double integral plant model, shows remarkable robustness and disturbance rejection in the presence of resonant modes, measurement noises and position and torque disturbances. It eliminates the needs for two separate controllers for track-seeking and track-following operations. The proposed feedforward controller in this 2DOF structure proves to be quite beneficial in reducing the …


Real-Time Plasma Controlled Chemistry In A Two-Frequency, Confined Plasma Etcher, Vladimir Milosavljevic, Albert R. Ellingboe, Cezar Gaman, John V. Ringwood Apr 2008

Real-Time Plasma Controlled Chemistry In A Two-Frequency, Confined Plasma Etcher, Vladimir Milosavljevic, Albert R. Ellingboe, Cezar Gaman, John V. Ringwood

Articles

The physics issues of developing model-based control of plasma etching are presented. A novel methodology for incorporating real-time model-based control of plasma processing systems is developed. The methodology is developed for control of two dependent variables (ion flux and chemical densities) by two independent controls (27 MHz power and O2flow). A phenomenological physics model of the nonlinear coupling between the independent controls and the dependent variables of the plasma is presented. By using a design of experiment, the functional dependencies of the response surface are determined. In conjunction with the physical model, the dependencies are used to deconvolve the sensor …


Airport Security Scanning, Nasro Mohamoud Jan 2008

Airport Security Scanning, Nasro Mohamoud

Ashiin

No abstract provided.


An Improved Robust Projection Identification Algorithm To Manned Maneuvering Units, Bin Xu Jan 2008

An Improved Robust Projection Identification Algorithm To Manned Maneuvering Units, Bin Xu

Bin Xu

空间载人机动装置(MMU )在进行救援过程中, 其动力学参数存在很大的不确定性。为解决这一辨识问题, 本文首先推导系统关于各动力学参数的线性化模型, 然后结合该线性模型的特点, 提出了一种用于估计动力学参数的改进鲁棒投影算法, 并在理论上分析了该算法的收敛性质, 数字仿真验证了方法的有效性。


Decoupling And Disturbance Rejection Control For Target Circulation, Jian Ma, Joon S. Lee, Woosoon Yim Jan 2008

Decoupling And Disturbance Rejection Control For Target Circulation, Jian Ma, Joon S. Lee, Woosoon Yim

Reactor Campaign (TRP)

The Target Complex loop TC-1 was originally conceived as part of an accelerator-driven system (ADS) pilot plant that was designed and developed by the Institute of Physics and Power Engineering (IPPE) and Experimental and Development Organization (EDO) “Gidropress” in Obninsk, Russia, under the International Science and Technology Center Project #559 in 1998. It was to be used as the target in a 1 MWth ADS experiment run off of the LANSCE proton accelerator at Los Alamos National Laboratory (LANL). When the U.S. transmutation program changed priorities from accelerator-driven systems towards nuclear fission reactors, the TC-1 loop was brought to UNLV …


Guidelines For Deploying Wireless Sensor Network In Manufacturing: Star Topology Study Using The Rssi To Test The Network Performance, A. Hameed Madwar Jan 2008

Guidelines For Deploying Wireless Sensor Network In Manufacturing: Star Topology Study Using The Rssi To Test The Network Performance, A. Hameed Madwar

Dissertations and Theses @ UNI

Wireless Sensor Networks (WSNs) are varying in kinds and can be used for many purposes. It can be extensively used in monitoring, reporting, and decision routines. Therefore, WSNs are very important to integrate with manufacturing since they can help not only in monitoring and decision making but also they can increase productivity and decrease the wiring costs. However, WSNs are facing some challenges in manufacturing as they need to resist the interferences that could be generated by the electrical and mechanical fields created during the manufacturing processes. Some of these interferences could be due to the high temperatures, blocks of …


Towards A Metric For The Assessment Of Safety Critical Control Systems, Oscar R. Gonzalez, Jorge R. Chavez-Fuentes, W. Steven Gray Jan 2008

Towards A Metric For The Assessment Of Safety Critical Control Systems, Oscar R. Gonzalez, Jorge R. Chavez-Fuentes, W. Steven Gray

Electrical & Computer Engineering Faculty Publications

There is a need for better integration of the fault tolerant and the control designs for safety critical systems such as aircraft. The dependability of current designs is assessed primarily with measures of the interconnection of fault tolerant components: the reliability function and the mean time to failure. These measures do not directly take into account the interaction of the fault tolerant components with the dynamics of the aircraft. In this paper, a first step to better integrate these designs is made. It is based on the observation that unstable systems are intrinsically unreliable and that a necessary condition for …


Using Student Presentations For Learning And Assessment: Some Experiences, Aidan O'Dwyer Jan 2008

Using Student Presentations For Learning And Assessment: Some Experiences, Aidan O'Dwyer

Conference papers

This contribution reports on, reflects on and evaluates the author’s experiences, over a number of academic years, of using formal student presentations as a means of learning and assessment in a taught postgraduate programme in engineering at Dublin Institute of Technology. Students were asked to prepare PowerPoint presentations on individual engineering topics; relevant references in books and technical papers were provided as assistance. Peer assessment of the presentations was employed, following a structured guideline agreed with the students. The contribution discusses the peer assessment experience in detail, including formal student feedback on the process. Some analysis work suggests that there …


Electric-Powered Wheelchairs As An Assistive Technology, Aidan O'Dwyer, Malabika Basu, Eugene Coyle Jan 2008

Electric-Powered Wheelchairs As An Assistive Technology, Aidan O'Dwyer, Malabika Basu, Eugene Coyle

Conference papers

This paper briefly outlines recent work done, particularly in control systems, for electric powered wheelchairs. These mobility aids, first developed in the 1950’s [1], were improved with the incorporation of microprocessors. The requirement for mobility aids in general is rising; for example, it is reckoned that 1.5% of the U.K. population require such aids. As an assistive technology, electric powered wheelchairs have many benefits. Nevertheless, a reliable and robust such wheelchair has still to evolve.


Boeing Welliver Faculty Fellowship, Raúl Ordóñez Dec 2007

Boeing Welliver Faculty Fellowship, Raúl Ordóñez

Raúl Ordóñez

$25500.


Motoman Robotics Laboratory, Raúl Ordóñez Dec 2007

Motoman Robotics Laboratory, Raúl Ordóñez

Raúl Ordóñez

PI, funded by Motoman in kind and UD in matching funds, $1M, established fall 2008. Supported by SAS, Sick, others.