Model based fault detection for two-dimensional systems

Fault detection and isolation (FDI) are essential in ensuring safe and reliable operations in industrial systems. Extensive research has been carried out on FDI for one dimensional (1-D) systems, where variables vary only with time. The existing FDI strategies are mainly focussed on 1-D systems and can generally be classified as model based and process history data based methods. In many industrial systems, the state variables change with space and time (e.g., sheet forming, fixed bed reactors, and furnaces). These systems are termed as distributed parameter systems (DPS) or two dimensional (2-D) systems. 2-D systems have been commonly represented by the Roesser Model and the F-M model. Fault detection and isolation for 2-D systems represent a great challenge in both theoretical development and applications and only limited research results are available. In this thesis, model based fault detection strategies for 2-D systems have been investigated based on the F-M and the Roesser models. A dead-beat observer based fault detection has been available for the F-M model. In this work, an observer based fault detection strategy is investigated for systems modelled by the Roesser model. Using the 2-D polynomial matrix technique, a dead-beat observer is developed and the state estimate from the observer is then input to a residual generator to monitor occurrence of faults. An enhanced realization technique is combined to achieve efficient fault detection with reduced computations. Simulation results indicate that the proposed method is effective in detecting faults for systems without disturbances as well as those affected by unknown disturbances.The dead-beat observer based fault detection has been shown to be effective for 2-D systems but strict conditions are required in order for an observer and a residual generator to exist. These strict conditions may not be satisfied for some systems. The effect of process noises are also not considered in the observer based fault detection approaches for 2-D systems. To overcome the disadvantages, 2-D Kalman filter based fault detection algorithms are proposed in the thesis. A recursive 2-D Kalman filter is applied to obtain state estimate minimizing the estimation error variances. Based on the state estimate from the Kalman filter, a residual is generated reflecting fault information. A model is formulated for the relation of the residual with faults over a moving evaluation window. Simulations are performed on two F-M models and results indicate that faults can be detected effectively and efficiently using the Kalman filter based fault detection. In the observer based and Kalman filter based fault detection approaches, the residual signals are used to determine whether a fault occurs. For systems with complicated fault information and/or noises, it is necessary to evaluate the residual signals using statistical techniques. Fault detection of 2-D systems is proposed with the residuals evaluated using dynamic principal component analysis (DPCA). Based on historical data, the reference residuals are first generated using either the observer or the Kalman filter based approach. Based on the residual time-lagged data matrices for the reference data, the principal components are calculated and the threshold value obtained. In online applications, the T2 value of the residual signals are compared with the threshold value to determine fault occurrence. Simulation results show that applying DPCA to evaluation of 2-D residuals is effective.Doctoral These

Computational and algebraic aspects of two-dimensional, linear, multivariable control systems

There are at present a large number of theoretical and algorithmic results relating to one-variable polynomial matrices arising from one-dimensional multivariable systems. In recent years many of the theoretical results have been extended to two-variable polynomial matrices arising from two-dimensional multi variable systems, such as delay-differential or partial differential systems. However there has been no major attempt to extend the algorithmic results associated with single variable polynomial matrices to two-variable or multivariable polynomial matrices. This thesis investigates further some of the extensions of the algebra of one-dimensional multivariable systems to two-dimensional multivariable systems. [Continues.

On the State Approach Representations of Convolutional Codes over Rings of Modular Integers

[EN] In this study, we prove the existence of minimal first-order representations for convolutional codes with the predictable degree property over principal ideal artinian rings. Further, we prove that any such first-order representation leads to an input/state/output representation of the code provided the base ring is local. When the base ring is a finite field, we recover the classical construction, studied in depth by J. Rosenthal and E. V. York. This allows us to construct observable convolutional codes over such rings in the same way as is carried out in classical convolutional coding theory. Furthermore, we prove the minimality of the obtained representations. This completes the study of the existence of input/state/output representations of convolutional codes over rings of modular integers.S

Measurements, Models, Systems and Design

531 s.

The current context of education and the middle school concept: what works in middle schools?

The goal of this project was to gain insight from public school middle school principals regarding what works in middle grades education and how accountability affected the organization of middle schools. Three research questions were considered in this exploratory study: 1. What is the status of the middle school model in the early 21st century? 2. According to middle school principals, how has No Child Left Behind and accountability affected their implementation of the middle school model? 3. How do middle school principals deal with the tensions between No Child Left Behind and the middle school model? In order to gain this insight, literature about middle schools was studied, two middle schools were visited, and human participants provided feedback through a survey. As a follow up to the survey, nine survey participants consented to a more in depth follow-up interview. Through this research it was determined that accountability standards are looked upon favorably by many administrators, however, the standards have forced some schools to restructure their days in ways that do not mirror the original middle school concept that still provides a framework for middle school education. Of the principals surveyed and interviewed there was still a strong desire to educate the whole child, to allow students opportunities to explore, and to develop relationships with students as the middle school model suggested. Based on the research the reader can surmise that the middle school concept can and should still be used in middle schools

Sliding Mode Control

The main objective of this monograph is to present a broad range of well worked out, recent application studies as well as theoretical contributions in the field of sliding mode control system analysis and design. The contributions presented here include new theoretical developments as well as successful applications of variable structure controllers primarily in the field of power electronics, electric drives and motion steering systems. They enrich the current state of the art, and motivate and encourage new ideas and solutions in the sliding mode control area

Space to lead: cognitive coaching as mindful school leader practice.

Anxious, stressed school leaders can adversely affect the climate and culture of the communities they serve. The multiple roles a principal must fulfill for their schools leave little room for renewal, self-development and reflection leaving principals feeling drained of energy and a true sense of continual mastery, leaving them with low self-efficacy and primed for burnout. Leaders engaged in growing their flexibility, mindful awareness, professional and personal development may be more resilient, agile, and responsive to the high demand of school administrator’s job. This study examined the experiences of 5 principals in a suburban school district as they engaged in Cognitive Coaching. Data were analyzed using The Listening Guide methodology according to the following two research questions: 1) How do principals describe perceived self-efficacy during and after a Cognitive Coaching cycle? and 2) How do principals describe their own mindful leader traits during and after a Cognitive Coaching cycle? Bandura’s Social Cognitive Theory provides the framework for this multiple case study investigating how principals describe perceived self-efficacy and mindful leader traits during and after Cognitive Coaching cycles. Principals reported feeling better prepared, focused, at ease, and confident after planning, reflecting, and problem solving with a Cognitive Coach. Leader education programs and district leaders should explore evidence based, job embedded strategies such as leader coaching and other mindful practice to help school leaders mitigate and regulate the stress of the job for the sake of retention and well-being

La Salle University Graduate Catalog 2009-2010

https://digitalcommons.lasalle.edu/course_catalogs/1191/thumbnail.jp