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<p>Rad je posvećen robusnom upravljanju sistemima čiji je linearni regulator i/ili dinamika necelog reda, kao i upravljačkim problemima gde regulator necelog reda u sebi poseduje i linearnu i nelinearnu dinamiku, a koji upravlja procesima čija dinamika može i linearna i nelinearna.</p> / <p>The thesys is dedicated to robust control systems problems with linear<br />controllers and/or process dynamics of noninteger order, as well as control<br />issues with combination of linear and nonlinear controllers of noninteger<br />order that control either linear or nonlinear systems.</p>

D. Litt. et Phil. / The influence of the human factor in the causation of accidents no doubt has been recognised from the very origins of humankind. In the words of Cicero "It is in the nature of man to err". Epithets such as 'human error', 'accident prone', 'inattentive', 'clumsy', 'drunk', etcetera form part of our everyday language to ascribe the reasons for accidents. In aviation, the general term 'pilot error' has been used to ascribe the cause of accidents since the time of the first heavier-than-air aircraft flights by the Wright brothers in 1903. The problem with this generalised term is that it offers no insight into why the pilot erred so that training steps may be undertaken to try to avoid the error from recurring – not only for the pilot concerned, but for the entire community. Under the direction of the Federal Aviation Administration (FAA) in the United States in 1976, Jensen and Benel determined that poor pilot decision-making is a significant factor in the causation of accidents in general aviation (Lester, Diehl, & Buch, 1985). These results were corroborated in an analysis of airline and military accidents by Diehl (1991b). The follow up to the Jensen and Benel findings was the development of training manuals by the Embry-Riddle Aeronautical University (ERAU) to address the identified problem. The effectiveness of these manuals in practice was tested empirically in experiments conducted in the U.S.A., Canada, and Australia that showed improvements in pilot decision-making ranging from 8% to 46% (Diehl, 1990). Simultaneously with this work airlines such as KLM and UAL developed their own human factors training programmes, which was the beginning of the significant industry of aviation human factors training. This activity has been supported academically through a bi-annual 'Symposium on Aviation Psychology' held at the University of Illinois since 1981. iv Since the initial verification of the ERAU training programmes, the continued support for aviation human factors training has come mainly from anecdotal evidence of its success in assisting pilots to avoid accidents. There is a paucity of experimental evidence to support this dynamic activity. Evidence for this is illustrated from the intense and extensive debate on the Crew Resource Management website (crmdevel@ yahoogroups.com) in 2001/2 on the topic "CRM – is it working?" Despite the widely accepted and even legislated (by the International Civil Aviation Organisation) application of aviation human factors training for pilots, this activity has been slow to filter through to other aviation activities. For example it was introduced into the South African air traffic control community for the first time only in 2001. With the introduction of this training the opportunity arose to develop a practical means to assess its effectiveness. This research study outlines the basis on which the developed assessment method has been achieved. The research method followed in the study is the Design and Development model of Thomas and Rothman (1994a). The disciplined approach to intervention development in the human sciences that the model demands, ensures that the parameters for the successful development of the intervention are clearly established in advance of its application, so that its validity can be assessed on an acceptable academic basis. It is confidently anticipated that the assessment questionnaire and the recommended procedures for its implementation will demonstrate whether or not human factors training (team resource management training [TRM training]) is effective in improving the attitudes and performance of air traffic controllers. A secondary outcome of this research project is the development of a TRM training manual for South African air traffic controllers and the measurement of the empirical results of this training. These results indicate positive acceptance, learning, and attitudinal changes as a result of the implementation of the training programme.

Uma das atribuições da engenharia de automação é o desenvolvimento de solução de automação e controle de processos contínuos industriais. Para tanto, a principal ferramenta emprega para este controle é a ação de controle Proporcional-Integral-Derivativo (PID). Nas últimas décadas diversas empresas fabricantes de equipamentos de automação industrial têm desenvolvido e aprimorado seus controladores industriais. Estes, além de realizarem o controle de processo por lógica de intertravamento, também possuem a ação de controle PID com a finalidade de executar o controle de processo contínuo como controle de velocidade, controle de pressão, controle de nível, etc. Porém, devido a grande variedade de controladores industriais por conseqüência, a grande variedade de implementações instrução PID, implica, muitas vezes, em falta padronização da programação e operação do algoritmo da equação PID implementados nos mais diversos controladores industriais. Tal fato dificulta a engenharia de automação industrial em desenvolver controle de processos contínuos através de instruções PID. Este trabalho de pesquisa aborda o desenvolvimento de metodologia \"MAFPID\" como ferramenta de engenharia de automação para aferir o funcionamento da instrução de controle PID implementada em equipamentos de controle e automação. Esta metodologia é constituída de três Etapas de testes. A primeira Etapa constitui o estudo do equipamento testado a partir das documentações fornecidas pelo fabricante. A segunda Etapa constitui de teste dos parâmetros proporcional, integral e derivativo, realizados no controlador industrial isolado de qualquer processo. A terceira Etapa constitui de teste do controlador interagindo com um circuito analógico. Este circuito simula o comportamento de alguns processos industriais, fornecendo ao controlador aferido sinais de entradas e de saída semelhantes aos processos reais. Este trabalho também apresenta dois estudos de caso, nos quais foi aplicada a metodologia MAFPID. / One of attributions of the automation engineering is the development of automation solution and control of industrial continuous processes. For in such a way, the main tool uses for this control is the action of Proportional-Integral-Derivative control (PID). In the last diverse decades companies equipment manufacturers of industrial automation have developed and improved its industrial controllers. These, besides carrying through the control of process for interlocking logic, also possess the action of control PID with the purpose to execute the control of continuous process as control of speed, control of pressure, control of level, etc. However, due to great variety of industrial controllers for consequence, the great variety of implementations instruction PID, it implies in lack standardization of the programming and operation of the algorithm of equation PID implemented in the most diverse industrial controllers. Such fact, it makes difficult the engineering of industrial automation in developing control of continuous processes through instructions PID. This work of research approaches the development of methodology MAFPID as tool of engineering of automation to survey the functioning of the instruction of control PID implemented in control equipment and automation. This methodology is constituted of three stages of tests. The first stage constitutes the study of the equipment tested from the documentations supplied for the manufacturer. The second stage constitutes of test of the parameters proportional, integral and derivative, carried through in the isolated industrial controller of any process. The third stage constitutes of test of the controller interacting with an analogical circuit. This circuit simulates the behavior of some industrial processes, supplying signals of input and output to the surveyed controller of similar to the real processes. This work also presents two studies of case, in which was applied methodology MAFPID.

Uma das atribuições da engenharia de automação é o desenvolvimento de solução de automação e controle de processos contínuos industriais. Para tanto, a principal ferramenta emprega para este controle é a ação de controle Proporcional-Integral-Derivativo (PID). Nas últimas décadas diversas empresas fabricantes de equipamentos de automação industrial têm desenvolvido e aprimorado seus controladores industriais. Estes, além de realizarem o controle de processo por lógica de intertravamento, também possuem a ação de controle PID com a finalidade de executar o controle de processo contínuo como controle de velocidade, controle de pressão, controle de nível, etc. Porém, devido a grande variedade de controladores industriais por conseqüência, a grande variedade de implementações instrução PID, implica, muitas vezes, em falta padronização da programação e operação do algoritmo da equação PID implementados nos mais diversos controladores industriais. Tal fato dificulta a engenharia de automação industrial em desenvolver controle de processos contínuos através de instruções PID. Este trabalho de pesquisa aborda o desenvolvimento de metodologia \"MAFPID\" como ferramenta de engenharia de automação para aferir o funcionamento da instrução de controle PID implementada em equipamentos de controle e automação. Esta metodologia é constituída de três Etapas de testes. A primeira Etapa constitui o estudo do equipamento testado a partir das documentações fornecidas pelo fabricante. A segunda Etapa constitui de teste dos parâmetros proporcional, integral e derivativo, realizados no controlador industrial isolado de qualquer processo. A terceira Etapa constitui de teste do controlador interagindo com um circuito analógico. Este circuito simula o comportamento de alguns processos industriais, fornecendo ao controlador aferido sinais de entradas e de saída semelhantes aos processos reais. Este trabalho também apresenta dois estudos de caso, nos quais foi aplicada a metodologia MAFPID. / One of attributions of the automation engineering is the development of automation solution and control of industrial continuous processes. For in such a way, the main tool uses for this control is the action of Proportional-Integral-Derivative control (PID). In the last diverse decades companies equipment manufacturers of industrial automation have developed and improved its industrial controllers. These, besides carrying through the control of process for interlocking logic, also possess the action of control PID with the purpose to execute the control of continuous process as control of speed, control of pressure, control of level, etc. However, due to great variety of industrial controllers for consequence, the great variety of implementations instruction PID, it implies in lack standardization of the programming and operation of the algorithm of equation PID implemented in the most diverse industrial controllers. Such fact, it makes difficult the engineering of industrial automation in developing control of continuous processes through instructions PID. This work of research approaches the development of methodology MAFPID as tool of engineering of automation to survey the functioning of the instruction of control PID implemented in control equipment and automation. This methodology is constituted of three stages of tests. The first stage constitutes the study of the equipment tested from the documentations supplied for the manufacturer. The second stage constitutes of test of the parameters proportional, integral and derivative, carried through in the isolated industrial controller of any process. The third stage constitutes of test of the controller interacting with an analogical circuit. This circuit simulates the behavior of some industrial processes, supplying signals of input and output to the surveyed controller of similar to the real processes. This work also presents two studies of case, in which was applied methodology MAFPID.

The thesis presents the development of force controller to maintain desired normal forces during a very stiff contact operation conducted in a Computer Numerical Control (CNC) machine. Force controller approach described in this thesis requires the accurate knowledge of the nominal tool path a priori. Obtaining the nominal tool path accurately is carried out by a vision based profile tracking system presented in this thesis. Both the force control and visual profile tracking systems require the development of an active control system to respond to force and vision signals. To facilitate the active control, a two-stage approach has been taken. The first stage is to bring the CNC machine under real-time control of an external computer. The second stage is the design of the active axis controller. This is achieved by adding sensor feedback loops to the external axis controller. The purpose of the active vision based profile tracking system is to automatically generate the tool path accurately. Emphasis is on combining low resolution vision with visual control of the precision CNC machine to attain the accuracy required for metal spinning. Combination of visual profile tracking and an edge detection method that gives sub-pixel accuracy were used to obtain the required tool path. A curvature detection algorithm was developed to identify segments of the tool path by assuming that the tool path consists of circular and straight line segments. The developed active force controller operates in a dynamic setup and is used to maintain tool forces at desired levels. The complete control system operates in a manner similar to reaction compensation and the force controller can be viewed as an integrating on-off controller with minimum integral wind-up effect. As a result, a direct dependency of the control efforts on error signals has been eliminated. In addition, the force controller brings in artificial damping that ensures the stability of the control system. To demonstrate the effect of the force controller, spun component qualities were assessed.

This thesis proposes an interactive software tool that can be used to compute complete sets of Proportional Integral Derivative (PID) Controllers from knowledge of the plant transfer function/frequency response data. This is based on research results and algorithms developed by Bhattacharyya and others. Until these research results were published, it was not known if a nominal system could be stabilized using PID Controllers, and current PID Controller designs are carried out using ad hoc tuning rules. By using simulations, engineers can best plan for and observe the stabilizing effect each of the variables has on system performance in a realistic environment. The software application developed calculates and optimizes complete stabilizing sets of PID Controllers for a rational Linear Time Invariant (LTI) system, and has been developed for analytical models of plants with and without time delay. Further, these PID Controller sets are optimized to project subsets simultaneously satisfying multiple performance index specifications. Sets of PID Controllers that stabilize a system are also calculated automatically from knowledge of the frequency response of the plant. It allows the user ease of design and the ability to customize the final solution while permitting full control over source parameters. This thesis includes an introduction to the algorithms that have been developed for plant stabilization, a complete description of the graphical user interface, the simulation of the algorithms performed using LabVIEW, and a summary of future work.

In real-time control systems, the value of a control decision depends not only on the correctness of the decision but also on the time when that decision is available. Recent work in real-time decision making has used machine learning techniques to automatically construct reactive controllers, that is, controllers with little or no internal state and low time complexity pathways between sensors and effectors. This paper presents research on 1) how a problem representation affects the trade-offs between space and performance, and 2) off -line versus on-line approaches for collecting training examples when using machine learning techniques to construct reactive controllers. Empirical results show that for a partially observable problem both the inclusion of history information in the problem representation and the use of on-line rather than off -line learning can improve the performance of the reactive controller. / Graduation date: 1994

This thesis aims to cover some aspects of synthesis and design of Proportional- Integral-Derivative (PID) controllers. The topics include computer aided design of discrete time controllers, data-based design of discrete PID controllers and data- robust design of PID controllers. These topics are of paramount in control systems literature where a lot of stress is laid upon identification of plant and robust design. The computer aided design of discrete time controllers introduces a Graphical User Interface (GUI) based software. The controllers are: Proportional (P), Proportional-Derivative (PD),Proportional-Integral (PI) and Proportional-Integral- Derivative (PID) controllers. Different performance based design methods with these controllers have been introduced. The user can either explore the performance by interactively choosing controllers one by one from the entire set and visualizing its performance or specify some performance constraints and obtaining the resulting set. In data-based design, the thesis presents a way of designing PID controllers based on input-output data. Thus, the intermediate step of identification of model from data is removed, saving considerable effort. Moreover, the data required is step response data which is easier to obtain in case of discrete time system than frequency response data. Further, a GUI developed for interactive design is also described. In data-robust design, the problem of uncertainty in data is explored. The design method developed finds the stabilizing set which can robustly stabilize the plant with uncertainty. It has been put forward as an application to interval linear programming. The main results of this research include a new way of designing discrete time PID controllers directly from the data. The simulations further confirm the results. Robust design of PID controllers with data uncertainty has also been established. Additionally, as a part of this research, a GUI based software has been developed which is expected to be very beneficial to the designers in manufacturing, aerospace and petrochemical industries. PID controllers are widely used in the industry. Any progress in this field is well acknowledged both in the industry and the academia alike. This thesis attempts a small step further in this direction.