Authors: M. A. Kaboudan

Abstract: This paper investigates the possibility of obtaining long-into-the-future reliable forecasts of observed nonlinear cyclical phenomena. Unsmoothed monthly sunspot numbers that are characteristically cyclical with nonlinear dynamics as well as their wavelet-transformed and wavelet-denoised series are forecasted through October 2008. The objective is to determine whether modelling wavelet-conversions of a series provides reasonable forecasts. Two computational techniques - neural networks and genetic programming - are used to model the dynamics of the series. Statistical comparison of their ex post forecasts is then used to identify the data set and computational technique to use under the circumstances.

Keywords: artificial intelligence,genetic algorithms,nonlinear systems

Identifier: 10.3182/20050703-6-CZ-1902.02242

Conference: Proceedings of the 16th IFAC World Congress, 2005

Location: , Czech Republic

Start Date: Mon Jul 04 2005 - End Date: Fri Jul 08 2005

Authors: G. Hulko; C. Belavy; Š. Cibiri; J. Szuda

Abstract: In the paper a web-based control design environment for distributed parameter systems control education is presented. It is arranged on www.dpscontrol.sk and includes: full downloadable demo version of Distributed Parameter Systems Blockset for MATLAB 8 Simulink with Show, Demos and DPS Wizard -- third-party MathWorks product; web Service for support control solutions via internet and internet monograph Modeling, Control and Design of Distributed Parameter Systems with Demonstrations in MATLAB. Some possibilities of this environment are indicated by control of complex shape 3D metal body heating - modeled by numerical structures of finite element method.

Keywords: control education,internet,distributed parameter systems,lumped-input/distributed-output systems,time/space decomposition of dynamics and control synthesis,distributed parameter PID,algebraic,state space,robust control,web based control design environment,finite element method

Identifier: 10.3182/20050703-6-CZ-1902.02277

Conference: Proceedings of the 16th IFAC World Congress, 2005

Location: , Czech Republic

Start Date: Mon Jul 04 2005 - End Date: Fri Jul 08 2005

Authors: R. Pastor; J. Sanchez; S. Dormido

Abstract: This paper presents an ongoing schema to develop virtual models of physical setup equipment and their integration into the corresponding remote laboratory. For this task, we use Easy Java Simulations (Ejs), a tool that allows us to make a complete simulation model based on the physical laws of the setup. Ejs is also able to produce virtual views that are necessary for model user interaction. These virtual views can be used with the simulation or real plant data. Accordingly, a communication model between Ejs and real equipment has to be defined in order to work with the same view in virtual mode (simulation) or remote mode (real setup). An example of a servomotor setup will be presented showing the virtual views and the way of working in both modes.

Keywords: remote and virtual laboratories,control education,web-based simulations,teleoperation,java simulations

Identifier: 10.3182/20050703-6-CZ-1902.02290

Conference: Proceedings of the 16th IFAC World Congress, 2005

Location: , Czech Republic

Start Date: Mon Jul 04 2005 - End Date: Fri Jul 08 2005

Authors: N. A. Pakshina

Abstract: In this paper the necessity of creating Web-quest "The History of Automatic Control Theory" is proved. Difficulties of using Internet-resource are described. General structure of the quest is given and selected chapter "The History of Linear Matrix Inequalities in Control Theory" is considered in details. This chapter devoted to scientists who have made significant contribution into development and application of linear matrix inequalities. The Web-pages of this chapter dedicated to such scientists as A. M. Lyapunov, V. A. Yakubovich, A. I. Lur'e, E. S. Pyatnitskii, V. M. Popov, G. Zames, J. C. Willems, S. P. Boyd and others. In conclusion the future works are discussed.

Keywords: internet,education,transliteration,web-pages,founders,linear matrix inequalities

Identifier: 10.3182/20050703-6-CZ-1902.02306

Conference: Proceedings of the 16th IFAC World Congress, 2005

Location: , Czech Republic

Start Date: Mon Jul 04 2005 - End Date: Fri Jul 08 2005

Authors: Daniel E. Miller

Abstract: In this paper we consider the use of linear periodic controllers (LPCs) to minimize the weighted sensitivity function in the face of a multiplicative gain uncertainty. We show that, under a technical assumption on the single-input single-output (siso) plant (it is relative degree one), on the weighting function (it is strictly proper), and on the multiplicative gain (it lies in a compact set not including zero), there exists a LPC which can provide a near LTI-optimal weighted sensitivity for every admissible gain.

Keywords: disturbance rejection,gain margin,robust performance,sampled-data systems,periodic control

Identifier: 10.3182/20050703-6-CZ-1902.00992

Conference: Proceedings of the 16th IFAC World Congress, 2005

Location: , Czech Republic

Start Date: Mon Jul 04 2005 - End Date: Fri Jul 08 2005

Authors: P. Hippe

Abstract: Presented is a two step windup prevention scheme with proven stability for observer based compensators possibly containing signal models for disturbance rejection. If the undesired effects of input saturation can solely be attributed to badly damped or unstable compensator dynamics (controller windup), they are prevented by simple structural measures not increasing the compensator order. Only if the destabilizing influence of input saturation is attributable to plant windup, additional dynamic elements are added to the controller.

Keywords: nonlinear systems,windup prevention,signal models for disturbance rejection

Identifier: 10.3182/20050703-6-CZ-1902.00688

Conference: Proceedings of the 16th IFAC World Congress, 2005

Location: , Czech Republic

Start Date: Mon Jul 04 2005 - End Date: Fri Jul 08 2005

Authors: Magnus Evestedt; Alexander Medvedev; Torbjorn Wigren

Abstract: The windup properties of a recently suggested recursive parameter estimation algorithm are investigated in comparison with a number of well-known techniques such as the Normalized Least Squares Algorithm (NLMS) and the Kalman filter (KF). An acoustic echo cancellation application is used as a benchmark for comparing the properties of different approaches. The basic performance of the method, both for white and colored input signal, appears to be similar to that of the KF and superior to the NLMS. When the energy in the input signal decreases, the algorithm performs best of all compared estimation schemes. Once the solution of the Riccati equation of the algorithm converged to a user defined point, it will stay there even if the input excitation is reduced. This explains the good anti-windup properties of the method.

Keywords: acoustic echo cancellation,recursive estimation,windup

Identifier: 10.3182/20050703-6-CZ-1902.00019

Conference: Proceedings of the 16th IFAC World Congress, 2005

Location: , Czech Republic

Start Date: Mon Jul 04 2005 - End Date: Fri Jul 08 2005

Authors: A. V. Nebylov; S. N. Danilov; V. A. Nebylov; E. A. Rumyantseva

Abstract: Seaplanes and WIG-craft are supposed to take the significant part of the projected air traffic growth without constructing new airstrips. However, a trouble-free flight at low altitude over the disturbed sea surface and also marine landing require the application of the special methods and means of motion control which are capable to solve the corresponding specific problems. Methods of stability providing and solving some other problems of WIG flight by means of automatic control are analyzed. The criteria for control systems improving are given. The experience and achievements in this field of high technology are described. Probable areas of the most effective application of vehicles with such equipment are indicated.

Keywords: flight control,low altitude flight,sea waves,radioaltimeter,sensors integration

Identifier: 10.3182/20050703-6-CZ-1902.02022

Conference: Proceedings of the 16th IFAC World Congress, 2005

Location: , Czech Republic

Start Date: Mon Jul 04 2005 - End Date: Fri Jul 08 2005

Authors: Mogens Mathiesen; Gilles Thonet; Niels Aakvaag

Abstract: This paper provides an overview of recent advances in wireless communication technologies applied to industrial automation. Newly introduced communication concepts such as ad-hoc networks and wireless sensor/actuator networks now enable the deployment of extremely decentralised control architectures. Both open-loop and closed-loop applications are part of the roadmap, although data gathering and monitoring applications are expected to spread first. In addition to increased flexibility and facilitated operations, these new communication technologies have significant cost saving potential. Standardisation efforts led by international bodies such as the IEEE should propel prototyping and deployment activities in various industries.

Keywords: networks,telecommunication,telematics,data transmission,connectivity,self-organizing systems,decentralised systems,decentralised control,open-loop control,closed-loop control

Identifier: 10.3182/20050703-6-CZ-1902.01170

Conference: Proceedings of the 16th IFAC World Congress, 2005

Location: , Czech Republic

Start Date: Mon Jul 04 2005 - End Date: Fri Jul 08 2005

Authors: Roberto Delgado; Arturo Molina; Istvan Mezgar; Paul Wright

Abstract: Wireless technology has evolved radically into key technologies that allow its application to Next Generation Manufacturing Systems. However the impact in nowadays business has been limited therefore a revision of relevant issues and trends is a must to establish a coherent vision for future research. This paper summarizes the underlying principles and challenges for the application of wireless technology, and its impact on next generation of manufacturing systems.

Keywords: manufacturing systems,sensor networks,wireless communication systems

Identifier: 10.3182/20050703-6-CZ-1902.01540

Conference: Proceedings of the 16th IFAC World Congress, 2005

Location: , Czech Republic

Start Date: Mon Jul 04 2005 - End Date: Fri Jul 08 2005

Authors: Mark Halton; Martin J. Hayes; Petar Iordanov

Abstract: This paper considers the application of the structured singular value, µ, and the skewed structured singular value, abbreviated "skew µ", to the analysis of a (deceptively) simple MIMO mass-spring-damper system. This example highlights some pertinent outstanding µ analysis questions, namely the effect of strictly real, possibly repeated parameters and the limitation of classical grid-based methods. It is shown that by transforming the original µ problem and using skew µ to calculate the worst case that more reliable and certifiably safe answers to the analysis question are determined. A comparison with more conventional µ analysis methods is presented.

Keywords: robust stability,uncertainty,structured singular value

Identifier: 10.3182/20050703-6-CZ-1902.01035

Conference: Proceedings of the 16th IFAC World Congress, 2005

Location: , Czech Republic

Start Date: Mon Jul 04 2005 - End Date: Fri Jul 08 2005

Authors: L'. Cirka; M. Fikar; J. Mikles

Abstract: The contribution is focused on the design of optimal LQ (Linear Quadratic) controller when the YK (Youla-Kuɩera) controller parameterisation is used. We provide a procedure for computing a deterministic optimal SISO (single-input single-output) 2DoF controller from any stabilising 2DoF controller.

Keywords: LQ control,parameterisation,spectral factorisation

Identifier: 10.3182/20050703-6-CZ-1902.00568

Conference: Proceedings of the 16th IFAC World Congress, 2005

Location: , Czech Republic

Start Date: Mon Jul 04 2005 - End Date: Fri Jul 08 2005

Authors: Anna Soffia Hauksdottir; Gisli Herjolfsson; Bergpor Avarsson; Sven P. Sigurosson

Abstract: The tuning of PID controllers can essentially be posed as the problem of selecting open-loop zeros such as to obtain a desired system response. In this paper, the general case wherein stable open-loop system zeros can be cancelled is considered, allowing more freedom in placing open-loop zeros, as opposed to just two zeros in the case of a PID controller. Subsequently, optimal open-loop zeros are computed such as to minimize the deviation from a desired reference impulse response, while maintaining the relative degree and the type of the reference system, thus giving the controlled system desired input tracking and disturbance rejection properties.

Keywords: linear continuous-time systems,zero optimizing controllers,tracking,disturbance rejection

Identifier: 10.3182/20050703-6-CZ-1902.00596

Conference: Proceedings of the 16th IFAC World Congress, 2005

Location: , Czech Republic

Start Date: Mon Jul 04 2005 - End Date: Fri Jul 08 2005

Authors: Fabio Camilli; Lars Grune; Fabian Wirth

Abstract: We consider a controlled stochastic system with an a.s. locally exponentially controllable compact set. Our aim is to characterize the set of points which can be driven by a suitable control to this set with some prescribed probability. We show that a generalization of Zubov's method leads to this characterization and can be used as basis for numerical computations.

Keywords: Zubov's method,stochastic control system,controllability probability,viscosity solution,computational approach

Identifier: 10.3182/20050703-6-CZ-1902.00443

Conference: Proceedings of the 16th IFAC World Congress, 2005

Location: , Czech Republic

Start Date: Mon Jul 04 2005 - End Date: Fri Jul 08 2005

Authors: Xiaohua Xia; Alan SI. Zinober

Abstract: Modulated feedback control introduces periodicity. The global attracting property of the periodic points is established for a simple scalar discrete-time system under Δ-modulated feedback. Attracting regions of the periodic points are also characterized. When the discretization effects of the equivalent control based sliding mode control systems are studied, we show that the zero-order-hold discretization gives rise to Δ-modulation in the sliding mode direction. The global attracting property of Δ-modulated feedback offers a vivid illustration of the way sliding happens. Interestingly, we find that a ZOH discretization scheme of the equivalent control based sliding mode control system with relative degree one results in only two-periodic orbits.

Keywords: delta-modulation,periodic points,sliding mode control

Identifier: 10.3182/20050703-6-CZ-1902.00773

Conference: Proceedings of the 16th IFAC World Congress, 2005

Location: , Czech Republic

Start Date: Mon Jul 04 2005 - End Date: Fri Jul 08 2005