Although high bandwidth for the pressure tracking of hydraulic actuators is highly desirable in many industrial applications, it has been a challenge to achieve, mainly due to the natural velocity feedback path in these actuators. In this paper, we investigate the extent to which a fixed-gain linear controller designed based on quantitative feedback theory (QFT) can improve the pressure trackin...

Most of the practical systems are characterized by high uncertainty which makes it difficult to maintain good stability margins and performance properties for closed loop system. In case of conventional control, if plant parameter changes we cannot assure about the system performance hence it is necessary to design robust control for uncertain plant. Among the various strategies proposed to tac...

IEEE Control Systems Magazine 119 Quantitative Feedback Design of Linear and Nonlinear Control Systems, by Oded Yaniv, Kluwer Academic, 1999, 369 pp., $140.00, ISBN 0-7923-8529-2; Quantitative Feedback Theory: Fundamentals and Applications, by Constantine H. Houpis and Steven J. Rasmussen, 1999, Marcel Dekker, 408 pp., $150.00, ISBN 0-8247-7872-3. Reviewed by Gerald Hearns. After years without ...

This paper represents ongoing research to reduce the computational cost of implementations of quantitative feedback theory (QFT), using ideas from Kharitonov stability theory and the theory of algorithms. By limiting our analysis to the simple case of a plant transfer function with denominator uncertainty, we gain insight into the problem of determining tracking, robust stability and actuator b...

The work presented expands upon previous research into the uses of fuzzy gain scheduling (FGS). It combines FGS with the robust control design methodology, quantitative feedback theory (QFT). By combining FGS and QFT the advantages from both methodologies are achieved, namely the resulting controller synthesis methodology provides design transparency, because of QFT, and does not suffer from ov...

This paper describes in detail the design methodology of a robust QFT (Quantitative Feedback Theory) controller for the control of the course changing of a ship. A linear model is used with uncertainty in the parameters. The system is designed to fulfil the specifications of robust stability and robust tracking of a reference system.

The Quantitative Feedback Theory (QFT) design technique, which has the ability to bridge the gap between theory and the real-world control design problem, is utilized in the design of a MIMO digital flight control system for an unmanned research vehicle (URV) that is presented in this paper. The design illustrates how the “real-world” knowledge of the plant to be controlled and the desired perf...

This paper presents a robust controller design for a Brush less DC motor by using Quantitative Feedback Theory [1] and its comparison with different control techniques. The different types of controller design techniques for a Brush Less DC motor involves (i) Fuzzy logic controller (ii)Genetic Algorithm based controller (iii)QFT Controller. The design of QFT controller involves preparation of p...

This paper aims at investigating the problem of Load Frequency Control (LFC) in interconnected power systems in order to obtain robustness against uncertainties. A design method for a robust controller, based on Quantitative Feedback Theory (QFT), has been presented in this paper. For a two-area power system, the simulation results show that the system response with the proposed QFT controller ...

Motion control and robust path tracking were the subject of this paper. A method based on fractional prefilter which is extended to multivariable systems is developed. This approach is based on the MIMO-QFT robust synthesis methodology combined with CRONE control. This paper incorporates Quantitative Feedback Theory (QFT) principles to CRONE control design procedure to solve the Two-Degree-Of-F...