A method of controller design for multiple input multiple output (MIMO) system is needed that will not give the high order controllers of modern control theory but will be more systematic than the “ad hoc” method. The objective of this method of design for multiple input multiple output systems is to find a controller of fixed order with performance specifications taken into consideration. An inner approximation of the stabilizing set is found through the algorithm discussed in Keel and Bhattacharyya’s "Fixed order multivariable controller synthesis: A new algorithm." The set satisfying the performance is then approximated through one of two algorithms; a hybrid of two optimization algorithms or the grid algorithm found in Lampton’s "Reinforcement Learning of a Morphing Airfoil-Policy and Discrete Learning Analysis." The method is then applied to five models of four aircraft; Commander 700, X-29, X-38, and F-5A using controllers of first and second orders.

Two robust control strategies are proposed in this dissertation for a class of multi-input multi-output dynamic systems with matched and mismatched perturbations. First of all, a novel design methodology of switching variables is proposed for solving the regulation problems. A serial state transformations are needed in order to design pseudo feedback gains and adaptive mechanisms. By utilizing the pseudo control input gain embedded in each of the switching variable, the proposed controller can not only suppress the mismatched perturbations when the controlled systems are in the sliding mode, but also attain locally asymptotic stability. The design of a robust output tracking controller is presented next for solving the tracking problems. Without utilizing the information of state variable, the proposed output feedback tracking controllers are capable of driving the state tracking errors into a small bounded region whose size can be adjusted through the designed parameters, and guarantee the stability of controlled systems. These two robust control schemes are designed by means of the variable structure control technique with sliding mode and Lyapunov stability theorem. Each controller contains three parts. The first part is for eliminating measurable feedback signals. The second part is used for adjusting the convergent rate of state variables (or tracking errors) of the controlled system. The third part is an adaptive control mechanism, which is to adapt some unknown constants of the least upper bounds of perturbations, so that the knowledge of the least upper bounds of matched and mismatched perturbations are not required. Several numerical examples and an application of controlling aircraft's velocity are demonstrated for showing the feasibility of the proposed control methodologies.

The state assignment is one of the most important problems in hardware implementation of controllers (finite state machines, FSMs). Traditional heuristics include simulated annealing (SA), greedy approach, and recursive Min-Cut partitioning. Since these methods can¡¦t reduce both area and power, thus we propose a new approach which using integer linear programming (ILP) to solve the state assignment. The proposed of ILP approach can set the weight and reach best solution between less area and low power. The approach can find out the best state assignment for both low-area and low power consumption. In addition, we also use ILP to solve the output encoding of controller in order to reduce the power consumption of datapath. Finally, to verify the effectiveness of our proposed approach, we do some experiments on several MCNC FSM benchmarks and controller-datapath systems. The experimental results show that a significant power and area savings can be achieved.

In this thesis a model reference adaptive sliding mode control scheme is proposed for a class of linear time-invariant MIMO systems with unstructured and input, output uncertainties to solve the robust tracking problems. The designing of the proposed control scheme is divided into three steps. The first step is to design the sliding functions, the second step is to construct the estimators of the lumped perturbation. These estimators are able to estimate the derivatives of the tracking errors. The third step is to design the adaptive sliding mode controller. The proposed control scheme is designed without requiring the information of the upper bound of perturbations, and guarantee the stability of the controlled system. In fact the asymptotical stability can be achieved for some special cases. Finally, three numerical examples are presented to demonstrate the feasibility of the proposed control scheme.

In this thesis, digital controller design methods for sampled-data nonlinear systems are considered. Although sampled-data nonlinear control has attracted much attention in recent years, the controller design methods for sampled-data nonlinear systems are still limited. Therefore, a range of controller design methods for sampled-data nonlinear systems are developed such as backstepping, adaptive and robust backstepping, reduced-order observer-based output feedback controller design methods based on the Euler approximate model. These controllers are designed to compensate the effects of the discrepancy between the Euler approximate model and exact discrete time model, parameter estimation error in adaptive control and observer error in output feedback control which behave as disturbance. A dual-rate control scheme is presented for output-feedback stabilization of sampled-data nonlinear systems. It is shown that the designed controllers semiglobally practically asymptotically (SPA) stabilize the closed-loop sampled-data nonlinear system. Moreover, various applications of these methods are given and their performances are analyzed with simulations.

名古屋大学博士学位論文 学位の種類 : 博士(医学)(論文) 学位授与年月日:平成5年1月28日 平山正昭氏の博士論文として提出された

Based on the Lyapunov stability theorem, an adaptive output feedback controller is proposed in this thesis for a class of multi-input multi-output (MIMO) dynamic systems with time-varying delay and disturbances. With an adaptive mechanism embeded in the proposed control scheme, the controller will automatically adapt the unknown upper bound of perturbation, so that the information of upper bounded of perturbations is not required. Once the controlled system reaches the switching hyperplane, not only the dynamics of system can be stabilized, but also the state trajectories can be driven into a small bounded region whose size can be adjusted through the design parameter. Two numerical examples are given for demonstrating the feasibility of the proposed control scheme.

Three categories of misfit have been identified in the software package implementation context. They are Data, Functional, and Output misfits. This study presents a methodology, based on the business form analysis and SEMINT technique, to help identify the Data and Output misfits. With this methodology, the software package acquiring organizations or consulting firms can more easily and systematically identify where the Data and Output misfits are and what the degree of misfits is. These results can contribute to the selection of a suitable software package and are valuable to the decision of either package customization or business process reengineering for the misfits during the package implementation.

This dissertation investigates the dynamic economic structure transformation and its corresponding environmental consequences at the Austin-San Marcos Metropolitan Statistical Area (Austin MSA) from 1990 to 2008. Input-output (IO) analysis is the major methodology and environmental problems are defined as emissions of industrial point air pollutants. Both three-and seven-segment IO models of Austin MSA for the years of 1990, 1994, and 1999 are constructed. Direct and total pollution coefficients of six major pollutants are calculated, hypothe tical extraction measurement and structural decomposition analysis are implemented, and the quantity and pattern of pollutant emissions are simulated based on four major assumed development scenarios from 2000 to 2008. This study finds: 1) the digital economy has emerged in the Austin MSA during the 1990s, 2) the manufacturing process of Austin MSA tended to be more environmentally friendly, which supports the hypothesis of dematerialization and decarbonization, 3) consumption-driven and non-production segments related environmental problems becomes more significant in the emerging digital economy. This study predicts that industrial point air pollutant emissions will grow moderately from 2000 to 2008, assuming that the direct pollutant coefficients will change at the average rates of the 1990s and the final demand will grow at the half rates of the 1990s?? average. Pollution contribution from production segment will generally decrease and contribution from other segments such as ICT and Information will increase, however, emission contributions of the segments will vary in terms of pollutants as well as development scenarios. This study argues that the shift of the source and nature of environmental threats of in the digital economy mandates parallel reform of the current environmental policy. A new generation of policy should be cooperative rather than confrontational, integrated rather than fragmented, flexible rather than rigid. It should also facilitate innovative management initiatives to achieve sustainability. More fundamentally, it is expected to deal with environmental impacts of intangible information flows (bits) which are possibly more essential than flows of tangible goods and services (atoms) in the context of the digital economy and the information age.

A novel algorithm for making the combination of outputs in the output zero direction of the plant always equal to zero was formulated. Using this algorithm and the result of MacFarlane and Karcanias, a fault detection scheme was proposed which utilizes the directional property of the multivariable linear system. The fault detection scheme is applicable to linear multivariable systems. Results were obtained for both continuous and discrete linear multivariable systems. A quadruple tank system was used to illustrate the results. The results were further verified by the steady state analysis of the plant.