5-th IFAC Symposium

15-th World Congress of IFAC

(Barcelona, SPAIN, July 2002)

S.D. Zemlyakov

V.A. Trapeznikov Institute of Control Sciences of RAS

Profsoyuznaya, 65, Moscow, 117997, Russia

The 15-th World Congress of the International Federation of Automatic Control was held at Barcelona (Spain) on July 21-26, 2002. It was the first IFAC World Congress in the Third Millennium. As such, it was a good opportunity to highlight the new directions of Automatic Control Science and Technology. In this context the Congress put emphasis on:

· Emergent Automatic Control Application Fields. New applications in industry and services, and their technological implications.

· Social Challenge of Automation and Control Theory. Analysis of the social impact of control and automation at the turn of the century.

· Use of Advanced Information Technologies of the Congress. The Congress itself is being an example of how advanced information technologies can promote scientific and technical exchange among international experts.

More than 2500 papers have been submitted to the IFAC’02 Congress and 1700 have been accepted, involving about 2300 authors from 68 countries.

The 11 selected Workshops were held during Saturday July 20 and Sunday July 21, prior to the Congress opening.

7 Plenary Sessions have been held for the five days of the Congress. Each day was start with a Plenary Session, followed by 20 parallel tracks organized in a morning session and a midday session and 2 posters sessions.

The Opening Ceremony was held at the “Gran Teatre del Liceu de Barcelona”, the most important Opera House in Spain.

The plenary speakers include some of the world’s most out standing authorities in various control fields.

The plenary paper by D.G. Luenberger “Systems Concepts in Financial Pricing Theory” outlines complementary aspects of pricing theory and system theory. Pricing theory is concerned with determining a realistic market-related price of an asset that is not yet marketed. There are several approaches to this issue, most of which use systems theory concepts, such as optimization, dynamic recursion, probability, stochastic process, and control. Pricing theory has therefore benefited greatly from systems theory. Systems theory can also benefit from pricing theory, for pricing theory provides critical guidance regarding the proper objective function for control problems involving random cash flow streams.

The plenary paper by K. Furuta “ Super Mechano-Systems: Fusion of Control and Mechanism» is dedicated to describing new mechanical systems with self-organizing capabilities. Super Mechano-System is the name of the research project at Tokyo Institute of Technology sponsored by the Japanese Ministry of Education, Culture, Sports, Science and Technology. The new mechanical system may have hyper redundant components with autonomous intelligence or several different functions, some of which integrate to have the most appropriate system for the objective in the varying environment by the fusion of control and mechanisms. The paper presents an aspect of the project relating to the control for the integration and its application to the control of the pendulum.

G.C. Goodwin in his plenary paper “Inverse Problems with Constraints” outlines some basic approaches to solving inverse problems. Many design questions in telecommunications, signal processing and control can be formulated as inverse problems. Moreover, there is a surprising degree of similarity in the solutions to the problems from diverse areas. Inverse problems become particularly interesting and difficult when the solution is required to satisfy hard or soft constraints. The paper has given a brief introduction to the topic of inverse problems with constraints. An outline of some of the available tools for solving these problems has been given as well as some indication of recent research results.

The plenary paper by J. Orasani, U. Fischer, J. Davison “Risk Perception: a Critical Element of Aviation Safety” adressed three issues relating to the role of pilot risk perception and the role of company policies in overall aviation safety:

- How do pilots think about flight risk? What risks are of greatest concern to them? What role does company policy play in their risk perception?

- How do pilots currently manage risk?

- How can flight crews be assisted in making safer decisions and in managing risk?

The survey paper by A. Fradkov and R. Evans “Control of Chaos: Survey 1997-2000” is a brief survey of the emerging field termed “Control of Chaos”. The survey is based on about 200 publications in peer reviewed journals. Three major branches of research are discussed in detail: “nonfeedback control” (based on periodic excitation of the system); OGY method (based on linearization of Poincare’ map ) and “Pyragas method”(based on a time-delay feedback).

The survey paper “Fault Isolation for Diagnosis: Nuisance Rejection and Multiple Hypothesis Testing ” is devoted to several statistical tools for solving the problems of fault detection, fault isolation and fault diagnosis. Particular emphasis is put on dealing with nuisance parameters and deciding between multiple hypotheses.

From Technical (Regular and poster) Sessions (more than 1500 papers) it is possible to light only some of them.

The paper by M. Vigyasagar, R.L. Karandikar “ A Learning Theory Approach to System Identification” describes a new approach to system identification and stochastic adaptive control, by viewing these as problems in statistical learning theory. If system identification is to be combined with robust control theory to provide a sound mathematical basis for indirect adaptive control, it is essential to have finite-time estimates of the sort provided by statistical burning theory.

A.V. Nazin and L. Ljung in their paper “Asymptotically Optimal Smoothing of Averaged LMS Estimators for Regression Parameter Tracking” consider the sequence of estimates formed by LMS algorithm for a standard linear regression estimation problem. It is shown that smoothing the LMS estimates using a matrix updating will lead to smoothed estimates with optimal tracking properties, also in the case the true parameters are slowly changing as a random walk. The same accuracy can be obtained also for a modified algorithm which is based on averages and requires much less computations.

There are a lot of the excellent results to be dissipated among these more than 1500 papers. Every specialist in the fields of control theory will discover good ideas or concrete results in his own field of activities after study of the Congress works.

The 15-th Triennial World Congress of IFAC was visited by many specialists from Russia. The paper by F.L. Chernousko, A. M. Shmatkov (Institute for Problems in Mechanics, RAS, Moscow) “New Results on Optimal Ellipsoidal Estimation for Uncertain Dynamical Systems” was devoted to the set – membership approach to the state estimation of dynamical systems subjected to uncertain disturbances.

A.B. Kurzhanski and P. Varaiya (Moscow State University and UC –Berkeley) in the paper “Reachability Under State Constraints: The Ellipsoidal Technique” describe the calculation of reachability sets for controlled processes under hard bounds on the controls and state space variables with on emphasis on linear systems.

I.A. Digailova and A.B. Kurzhanski (Moscow State University) presented the paper “The Joint Model and State Estimation Problem Under Set –membership Uncertainly” where they deals with combined estimation of the state and of the system model under set –membership bounds on the transfer functions and the input disturbances.

The paper by B. Polyak, S. Nazin, C.Durieu, E. Walter (Russia, France) devoted ellipsoidal outer – bounding under model uncertainty as a natural extension of state estimation for models with unknown – but – bounded errors.

Prof. A. Nebylov (State University of Aerospace Instrumentation, St. Petersburg, Russia) was the chair of the Session “Aircraft Control” and presented the paper “Controlled Flight Close to Rough Sea: Strategies and Means”. The paper included the statement of the main problems of equipment and software design for flight control at small altitude above the disturbed surface.

Ye.I. Somov (Russia) was the Co-chair of the Session “Nonlinear, Robust and Fault Tolerant Aerospace Control Systems” and presented the paper by Ye.I. Somov, A.G. Kozlov, V.A. Rayevsky, G.P. Anshakov and Yu.G. Antonov “Nonlinear Dynamic Research of the Spacecraft Robust Fault Tolerant Control Systems”.

At the same Session prof. V.Yu. Rutkovsky (Institute of Control Sciences, RAS, Moscow) presented the paper by V.Yu. Rutkovsky, V.M. Sukhanov, V.M. Glumov, S.D. Zemlyakov, U. Kirchhoff (Germany) “Nonlinear Combined Control by Space Robotic Module Motion With Using Manipulator’s Mobility”.

Stanislav D. Zemlyakov, Dr. Sci (Eng.), Professor, Academician of ANS, Head of Department of the V.A. Trapeznikov Institute of Control Sciences of RAS. The main of scientific interest domain: the theory of adaptive coordinate-parametric control by nonlinear nonstationary objects and its application to aircraft and spacecraft control.