Some references about Quantitative Feedback Theory (QFT) Control


Interactive computer-aided control design using quantitative feedback theory: the problem of vertical movement stabilization on a high-speed ferry

J. M. Díaz, S. Dormido and J. Aranda

International Journal of Control . Vol. 78, No. 11, 20 July 2005, 813–825. ( full text )


In a first approximation, the vertical acceleration associated with pitch motion can be considered as the main cause of motion sickness, which is without a doubt one of the most unpleasant disadvantages of maritime transport. The reduction of motion sickness can be stated as a monovariable regulation problem of a highly perturbed system. This work presents the design of a monovariable robust controller with Quantitative Feedback Theory for reducing the vertical movement on a high-speed ferry. The different stages of QFT methodology have been done with the help of QFTIT. This is a free software tool that is characterised by its ease of use and interactive nature. The designed regulator is validated experimentally in sea behaviour trials with a scaled down replica 1/25 the size of a high-speed ferry. The designed regulator is also compared with a gain-scheduling scheme using a PD controller.


Design of a multivariable robust controller to decrease the motion sickness incidence in fast ferries

J. Aranda, J.M. de la Cruz, J.M. Díaz

Control Engineering Practice . Vol 13/8.. 2005. Pp: 985-999. CEP


This work provides one of the first contributions in the field of the design of a multivariable robust controller with QFT methodology for the reduction of motion sickness incidence on a high-speed ferry. Motion sickness is caused by vertical accelerations associated with the heave and pitch motions induced by waves, it is therefore a regulation problem of a highly perturbed system. The design regulator is validated experimentally in sea behaviour trials with a scaled down 1/25 replica of a high-speed ferry.


QFT for the Design of an Aircraft Flight Control.

Alexander Santander, Joaquín Aranda.

IFAC World Congress. 2005.


Aircraft flight control has a multivariable and non linear nature that makes it suitable for a verification of control capability of different designs. QFT techniques have been thoroughly used during the last years to provide robust control designs while using classic theory of control. The QFT method is applied to the design of an aircraft flight control and the results, evaluated by means of an automated software, can be compared to results obtained with different methodology approaches.


QFT Robust Control Design by Interactive Approach

J. M. Díaz, S. Dormido, and J. Aranda

44th IEEE Conference on Decision and Control, and European Control Conference. 2005. Pp. 1301-1036. ISBN:0-7803-95668-9


In this paper an illustrative robust regulation problem is solved using a new QFT design interactive software tool. The proposed example is the same used in the manual of QFT Frequency Domain Control Design Toolbox to explain its use. Thus, a habitual user of this Matlab toolbox will be able to easily perceive the advantages and limitations of the new interactive software tool. This tool can be used for novice users in order to learn and understand the basic concepts involved in QFT design. However, it can be used for advanced users to solve real problems of robust control design


Robust control for the coupling of lateral and longitudinal dynamics in high-speed crafts

Joaquín Aranda, Rocío Muñoz-Mansilla, José Manuel Díaz, S. Dormido-Canto

Praga 2005. World congress IFAC


In this work, the QFT technique was used to control a system with three degrees of freedom of coupled movement. The example is the coupling between the vertical and the horizontal dynamics of a high-speed craft. Since the angle between the heading and the seaway is different from 180 degrees, the action of the actuators for controlling each dynamic produces a coupling in the other dynamic. Firstly, controllers for the two dynamics were designed separately. Then, the actuator coupling was considered, and finally, it was shown how the controllers reduce the three coupled modes in the whole system.


QFT versus classical gain scheduling: study for a fast ferry

J. Aranda, J. M. de la Cruz, J.M. Díaz, S. Dormido Canto

B’02 IFAC World congreso 2002
Proceedings of the 15th IFAC World Congress
by L Basenez, et al


In this paper a comparative study of two different control strategies is done: Gain scheduling with classic controllers (PD and second order filter) versus QFT. Both of them are used to decrease motion sickness in a high speed ferry produced by the vertical acceleration associated with heave and pitch motion.