Decentralized reliable control for large-scale LTI systems

Reliable control concerns the ability of closed loop system to maintain stability and regulation properties during arbitrary sensor, controller, and actuator failure. Reliable control research has been an active research topic for more than 10 years. Recent approach for reliable control includes the H∞ method, the algebraic factorization design, and the robust servomechanism control. These methods have been surveyed and discussed in this thesis with the robust servomechanism control methodology serving as the basis of the research development of this work. In this thesis, the reliable control for large-scale, multi-input/output linear system is considered. Two concepts of reliable control are introduced in this work: (1) Decentralized Robust Servomechanism Problem with Complete Reliability (DRSPwCR) and (2) Block Decentralized Robust Servo Problem with Complete Reliability (BDRSPwCR). The DRSPwCR solves the reliable control problem by applying strict diagonal decentralized controller configurations. The BDRSPwCR solves the reliable control problem by applying block diagonal decentralized controller configurations. Research results of solving DRSPwCR for the class of minimum phase systems is first developed in this work. The problem is solved by applying strict decentralized PIDr control to an otherwise unreliable plant and thus significantly extending the class of processes that can be controlled reliably. Research results of solving BDRSPwCR is developed for plants which have a pre-imposed block diagonal structure or plants with non-minimum phase minors. The reliable control conditions for an arbitrary linear system is then analyzed, and a general controller synthesis for solving the reliable control problem for arbitrary linear system is given in this work. The DRSPwCR can be applied in many industry areas as well as in the transportation area. In this work, the reliable control results are applied in the urban vehicle traffic network. A traffic queue length model is developed, a control algorithm is synthesized, and simulations are made under different traffic subsystem failure modes such as non-functioning traffic lights, traffic accidents, and intersection blockage, etc. Finally, future research topics such as to relax the constraints of plants to achieve reliable control and to optimize the closed loop system dynamic performances, etc. are proposed

Advances and open problems on the control of large scale systems

Bibliography: leaves 10-12.ONR Contract N00014-76-C-0345 and ERDA Contract E-(49-18)-2087.by Michael Athans

Disturbance Observer-based Robust Control and Its Applications: 35th Anniversary Overview

Disturbance Observer has been one of the most widely used robust control tools since it was proposed in 1983. This paper introduces the origins of Disturbance Observer and presents a survey of the major results on Disturbance Observer-based robust control in the last thirty-five years. Furthermore, it explains the analysis and synthesis techniques of Disturbance Observer-based robust control for linear and nonlinear systems by using a unified framework. In the last section, this paper presents concluding remarks on Disturbance Observer-based robust control and its engineering applications.Comment: 12 pages, 4 figure

Distributed infinite-horizon optimal control of continuous-time linear systems over network

This article deals with the distributed infinite-horizon linear-quadratic-Gaussian optimal control problem for continuous-time systems over networks. In particular, the feedback controller is composed of local control stations, which receive some measurement data from the plant process and regulates a portion of the input signal. We provide a solution when the nodes have information on the structural data of the whole network but takes local actions, and also when only local information on the network are available to the nodes. The proposed solution is arbitrarily close to the optimal centralized one (in terms of cost index) when a design parameter is set sufficiently large. Numerical simulation validate the theoretical results

Research on optimal control, stabilization and computational algorithms for aerospace applications

The research carried out in the areas of optimal control and estimation theory and its applications under this grant is reviewed. A listing of the 257 publications that document the research results is presented

H2, fixed architecture, control design for large scale systems

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1990.Includes bibliographical references (p. 227-234).by Mathieu Mercadal.Ph.D

Optimized state feedback regulation of 3DOF helicopter system via extremum seeking

In this paper, an optimized state feedback regulation of a 3 degree of freedom (DOF) helicopter is designed via extremum seeking (ES) technique. Multi-parameter ES is applied to optimize the tracking performance via tuning State Vector Feedback with Integration of the Control Error (SVFBICE). Discrete multivariable version of ES is developed to minimize a cost function that measures the performance of the controller. The cost function is a function of the error between the actual and desired axis positions. The controller parameters are updated online as the optimization takes place. This method significantly decreases the time in obtaining optimal controller parameters. Simulations were conducted for the online optimization under both fixed and varying operating conditions. The results demonstrate the usefulness of using ES for preserving the maximum attainable performance

A state-of-the-art assessment of active structures

A state-of-the-art assessment of active structures with emphasis towards the applications in aeronautics and space is presented. It is felt that since this technology area is growing at such a rapid pace in many different disciplines, it is not feasible to cover all of the current research but only the relevant work as relates to aeronautics and space. Research in smart actuation materials, smart sensors, and control of smart/intelligent structures is covered. In smart actuation materials, piezoelectric, magnetostrictive, shape memory, electrorheological, and electrostrictive materials are covered. For sensory materials, fiber optics, dielectric loss, and piezoelectric sensors are examined. Applications of embedded sensors and smart sensors are discussed

NASA Aircraft Controls Research, 1983

The workshop consisted of 24 technical presentations on various aspects of aircraft controls, ranging from the theoretical development of control laws to the evaluation of new controls technology in flight test vehicles. A special report on the status of foreign aircraft technology and a panel session with seven representatives from organizations which use aircraft controls technology were also included. The controls research needs and opportunities for the future as well as the role envisioned for NASA in that research were addressed. Input from the panel and response to the workshop presentations will be used by NASA in developing future programs

Technology for large space systems: A bibliography with indexes (supplement 10)

The bibliography lists 408 reports, articles and other documents introduced into the NASA scientific and technical information system to provide helpful information to the researcher, manager, and designer in technology development and mission design in the area of large space system technology. Subject matter is grouped according to systems, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems