MA1 Hybrid Systems I (invited) Organized by: Pappas G. - University of Pennsylvania, USA Lygeros J., University of California at Berkeley, USA Antsaklis P., University of Notre Dame, USA Fundamental Properties of Hybrid Dynamical Systems Authors: Lygeros J., University of California at Berkeley, USA Johansson K.H., University of California at Berkeley, USA Zhang J., University of California at Berkeley, USA Sastry S., University of California at Berkeley, USA ABSTRACT Basic dynamical features of hybrid systems are reviewed in this paper. Some results on existence and uniqueness of executions for hybrid automata are obtained. Continuous dependence on initial states are shown for a class of hybrid automata. Zeno hybrid automata, i.e., hybrid automata that exhibit infinitely many discrete transitions in finite time, are also discussed. ma1-1.pdf Constrained Optimal Control for Multi-Stage Hybrid Manufacturing System Models Authors: Gokbayrak K., Boston University, USA - Cassandras C., Boston University, USA ABSTRACT We consider a multi-stage manufacturing process where each job has a physical state characterized by time-driven dynamics and a temporal state by event-driven dynamics, thus giving rise to a hybrid system model. A common problem is to derive an optimal control strategy to trade othe conflicting objectives of minimizing job completion times (satisfaction of customer demand) against the quality of the completed jobs. Extending our past work, in this paper we derive necessary conditions for optimality for a multi-stage system where the control inputs are bounded. The issue of nondifferentiability due to the nature of the event-driven state dynamics creates serious analytical diculties which we can no longer eectively resolve using nonsmooth optimization methods. Instead, we establish some properties of the optimal control sequence that have interesting implications in terms of designing control policies for this class of hybrid systems. Key Words. Hybrid Systems, Optimal Control ma1-2.pdf Automotive Engine and Power-Train Control: a Comprehensive Hybrid Model Authors: Balluchi A., PARADES G.E.I.E., Italy Benvenuti L., PARADES G.E.I.E., Italy Di Benedetto M.D., PARADES G.E.I.E., Italy Pinello C., PARADES G.E.I.E., Italy Sangiovanni-Vincentelli A.L., - PARADES G.E.I.E., Italy ABSTRACT The design of engine control systems has been traditionally carried out using heuristic techniques validated by simulation and prototyping using approximate average-value models. Increasing demands on controllers performance call for more robust techniques and the use of cycle{accurate models. In this paper we present a hybrid model of the engine and powertrain in which both continuous and discrete time{domain as well as event-based phenomena are modeled in a separate but integrated manner. ma1-3.pdf A Differential Game with Graph Constrained Switching Strategies Authors: Borges de Sousa J., Universidade do Porto, Portugal Pereira F.L, Universidade do Porto, Portugal ABSTRACT In this paper paper we discuss a two-person zero- sum differential game of finite horizon with graph- constrained control strategies. Both players are constrained to use piecewise constant controls, where the control switches are selected from a finite control graph. The control graph is a directed graph where the vertices define pairs of control values for both players, and the edges define the allowable control switches. Each edge represents a positive switching cost. The payoff function includes the sum of the switching costs associated with each player. We prove the existence of value and state optimality conditions in terms of value functions that solve a coupled system of quasi-variational inequalities. Optimal strategies are then derived in terms of these value functions. Keywords: Hybrid systems, graph games, di er- ential games, switching strategies, non-smooth anal- ysis and control. ma1-4.pdf Contribution to the Fault Detection for Hybrid Systems Authors: Fourlas K.G., National Technical University of Athens, Greece Kyriakopoulos J.K., National Technical University of Athens, Greece Krikelis J.N., - National Technical University of Athens, Greece ABSTRACT In this work we propose an approach to the problem of failure diagnosis for Hybrid Systems (HS). This approach is applicable to a wide rage of systems since hybrid systems involve both continuous and discrete dynamics. The states of the HS model reflect the normal and the failed status of the system components. The faults in our setting are modeled as either discrete or continuous (detrimental) state changes. Key Words. Fault diagnosis, failure detection, hybrid systems. ma1-5.pdf Advances in Linear Systems I Control of Nested Systems Authors: Voulgaris P., - University of Illinois at Urbana-Champaign, USA ABSTRACT This paper presents an input-output point of view for the problem of optimal command following and disturbance rejection of systems which are comprised of subsystems that affect each other in a nested manner. In such a nested manner, a subsystem affects the subsystems that are exterior to it but not the subsystems that are interior to it. By using model matching methods the problem is shown to be convex. Techniques to solve this convex yet non-standard problem are discussed. ma2-1 On a general descriptor LQ problem Authors: Nikoukhah R., INRIA, France Delebecque F., INRIA, France Campbell S.L., North Carolina State University, USA ABSTRACT A discrete-time descriptor linear quadratic (LQ) optimization problem is considered. This problem can be con-sidered as a generalization of many standard LQ problems including Kalman filters. A complete recursive solution based on a novel Riccati equation is presented. The limiting case when the size of the interval goes to infinity is studied. ma2-2 Convolution Profiles for Noncausal Inversion of Multivariable Discrete-Time Systems Authors: Marro G., Universita di Bologna, Italy Prattichizzo D., Universita di Siena, Italy Zattoni E., Universita di Bologna, Italy ABSTRACT Noncausal inversion of discrete-time linear multivariable systems is analyzed in the geometric approach framework with the aim of computing convolution profiles that ensure perfect tracking with infinite preaction and infinite postaction time. It is shown how this computation is related to the concepts of multivariable output relative degree and invariant zeros of the plant. Then, a computational setting for the convolution profiles is derived by using the standard geometric approach tools. Key Words. Geometric approach, noncausal inversion, discrete-time systems, convolution profiles. ma2-3 Design for Well Conditioning of Progenitor Models by Input, Output Reduction Authors: Karcanias N., City University, United Kingdom Vafiadis K., City University, United Kingdom ABSTRACT Transfer function models used for early stages of design are large dimension models containing all possible physical inputs, outputs. Such models may be badly conditioned and possibly degenerate. The problem considered here is the selection of maximal cardinality subsets of the physical input, output sets, such as the resulting model is nondegenerate. This problem is part of the early design task of selecting well- conditioned progenitor models on which successive design has to be carried out. The established conditions for different type of degeneracy are used to define necessary and sufficient conditions required to guarantee nondegeneracy. A simple redesign procedure that guarantees transfer function and input, output nondegeneracy is suggested and parameterisation of all such solutions is given. The results provide the basis for selection of well-conditioned transfer function models, which may be used for subsequent control design. Key Words. Integrated design, process control, system structure, linear systems. ma2-4 Non Integer Order Systems Authors: Nikolov E., Technical University of Sofia, Bulgaria ABSTRACT The novelty in this working is the suggested class of astatic control systems. The article proposes: DASCRONE and DASCRONE_GSC structures; synthesis algorithm; robast analysis. The synthesis is based on the wave disturbances absorbing principle, non integer differentiation, gain scheduled control, parametric and structure independence of the stability margin. Keywords: robast control, non integer order disturbance absorbing systems, robast analysis. ma2-5 MA3 Nonlinear Systems Stable Inversion of Discrete-Time Nonlinear Maximum Phase Systems Authors: Li S., Georgia Institute of Technology, USA Taylor D., Georgia Institute of Technology, USA ABSTRACT This paper formulates and solves the problem of stable inversion for a class of discrete-time nonlinear systems possessing either completely stable or completely unstable zero dynamics. Given a desired output trajectory, the new stable inversion method determines bounded desired trajectories for the input and state variables that satisfy the plant state and output equations. The desired input and state trajectories may be used as feedforward signals for tracking control purposes, and/or they may be used to study the influence of plant parameters on control requirements. The stable inversion process involves numerical calculations with Newton iterations and is causal for minimum-phase systems and noncausal for maximum-phase systems. An appli-cation to an electronic power conversion circuit illustrates the significant benefits of computing the feedforward input using stable inversion instead of the more traditional dc-gain method, including large reductions in peak transient error, settling time and overshoot. Keywords: digital control, feedforward control, nonlinear systems, nonminimum-phase systems, power converters. ma3-1 Nonlinear Controllers for Nonlinear Passive Systems with Arbitrary Input Nonlinearities Authors: Haddad W., Georgia Institute of Technology, USA Chellaboina V., University of Missouri-Columbia, USA ABSTRACT A nonlinear dynamic compensator framework for nonlinear passive systems with arbitrary input nonlinearities is proposed. For this class of systems we prove global closed-loop stability by modifying the dynamic compensator to include a suitable input nonlinearity. The proof of this result is based on dissipativity theory and shows that the nonlinear controller modification counteracts the effects of the input nonlinearity by recovering the passivity of the plant and the compensator. Key Words. Nonlinear control, passive systems, actuator nonlinearities, dissipativity theory ma3-2 A Small-Gain Theorem for Locally Input-to-Output Stable Interconnected Systems Authors: Tzamtzi M., Institute of Accelerating Systems and Applications, Greece ABSTRACT The results of the present paper extend the nonlinear small-gain theorem to the case of "local input-to-output practical stability". The criterion which must be satisfied by the gain functions can give results for a wide class of systems, since it can be applied to gain functions that cannot be overbounded by any linear function in a neighborhood of zero. Key Words: nonlinear systems, small-gain theorem, input-to-output practical stability (IOpS) ma3-3 A stabilization methodology for invariant systems on Lie groups Authors: Apostolou N., University of Patras, Greece Kazakos D., University of Patras, Greece ABSTRACT This paper deals with the stabilizability of invariant control systems defined on Lie groups. A stabilization technique is presented which under certain hypotheses can lead to a criterion assuring the existence of a feedback controller which steers every initial condition to a specified target point of the state space of these systems. Key words: Invariant systems, stabilization, Lie groups. ma3-4 Self-Modulation in Nonlinear Feedback Systems with Jump Resonance Authors: Nemescu M., Technical University "Gh. Asachi", Romania Temneanu M., Technical University "Gh. Asachi", Romania ABSTRACT The paper proposes to present in a compact form, the phenomenon of self-modulation that is likely to appear in nonlinear feedback systems presenting jump resonance. The system contains a time slow variable parameter depending on the modification by jump of the output signal. Due to this, the output signal undergoes a process of self-modulation in amplitude and phase through resonance jumps. Key Words. Nonlinear feedback system, jump resonance, self-modulation. ma3-5 MB1 Performance Improvement in Control Loops Modification and Application of Autotuning PID Controller Authors: Peric N., Faculty of Electrical Engineering and Computing, Croatia Branica I., Faculty of Electrical Engineering and Computing, Croatia Petrovic I, Faculty of Electrical Engineering and Computing, Croatia ABSTRACT This contribution presents a modified autotuning algorithm of the PID controller. The motivation for the modification of the basic autotuning algorithm is to enlarge the class of processes to which it can be applied. The basic autotuning algorithm introduced by Astrom and Hagglund is extended by the preliminary identification procedure and through the usage of the dead time compensating controller. These modifications are detailed through the description of the algorithms' functioning. The proposed algorithm has been implemented in the programmable logic controller (PLC) Siemens SIMATIC S7-300. The experimental results confirm the good robustness properties of the proposed algorithm, which were demonstrated in a simulation study. Key Words. Autotuning, PID control, relay experiment, PLC. mb1-1 Tuning of PID Controller for Interval Plants Authors: Tan N., University of Sussex, United Kingdom Kaya I., University of Sussex, United Kingdom ABSTRACT The paper deals with the problem of controller design for guaranteed phase margin when the plant include parameter uncertainty. Some results from the area of parametric robust control related to interval systems are combined with the Astrom- Hagglund method to design robust PIDcontroller. Keywords: Interval systems; Robust control; Astrom-Hagglund method mb1-2 Improving performance of single input stable LTI systems with positive controls Authors: Angelis Z.G., Eindhoven University of Technology, The Netherlands Van de Molengraft J.G.M., Eindhoven University of Technology, The Netherlands Nijmeijer H., Eindhoven University of Technology, The Netherlands ABSTRACT An easy applicable regulator design for stable Linear Time Invariant (LTI) systems with positive controls is presented.The synthesis algorithm is derived on the basis of Lyapunov stability theory and quadratic performance measures.The synthesis algorithm is given as a convex optimization routine,a set of Linear Matrix Inequality (LMI)conditions together with the maximization of some variables.Performance im- provement with respect to the open oop system will be attained,if the oop is closed with the a priori imposed static state feedback control aw,u =max(0 ,Fx ),of which the feedback matrix F has to be determined.Examples are given that illustrate the applicability of the derived synthesis algorithms.More speci .cally,the examples show that costs,i.e.output energy can be reduced and signi .cant disturbance reduction can be achieved. Key Words.Piecewise Linear Models,Positive Controls,Stabilization,Performance Analysis. mb1-3 New PI controller tuning formulas for unstable first- order plus dead-time processes Authors: Arvanitis G.K., Aristotle University of Thessaloniki, Greece Sigrimis N., Agricultural University of Athens, Greece Pasgianos D.G., National Technical University of Athens, Greece Kalogeropoulos G., University of Athens, Greece ABSTRACT New methods for tuning PI controllers for unstable first order plus dead-time (UFOPDT) processes are reported. In contrast to known methods that result on overshoot in the closed- loop response or require the modification of the feedback structure, the pro-posed methods ensure smooth closed-loop response to set-point changes, fast attenuation of step load disturbances and robustness against parametric uncertainty while retaining the classical PI controller structure. This enhanced performance is plausible by the use of a first order set-point filter and by the application of some new accurate approximations of the crossover frequencies of the Nyquist plot for UFOPDT models. The proposed methods require small computation effort and they are particularly useful for on-line applications. Finally, they are favorably compared to the already known PI controller tuning methods. Keywords: PI controller tuning, process control, unstable processes, dead-time processes. mb1-4 Analytic Synthesis, by means of normalized diagrams, of standard regulators for SISO control systems Authors: Penati M. E., University of Bologna, Italy Zanzi M., University of Bologna, Italy ABSTRACT In this paper we will present some procedures for the analytic synthesis,by means of feedforward and feedback standard regulators,of some SISO control systems when the order of the system itself doesn't go beyond the third. These procedures utilize normalized diagrams obtained in [12 ]which supply the relations between the parameters of the above systems and their outputs to canonical inputs. Consequently,these procedures supply,for each of the above systems,proper normalized diagrams which,therefore,can be utilized whatever the numerical values of the parameters are. Key Words.Analytic synthesis,Standard regulators,PD,PI,Hybrid regulators. mb1-5 MB2 Linear Systems I: Theory Reachability and Controllability of 2D Positive Linear Systems with State Feedbacks Authors: Kaczorek T., Warsaw University of Technology, Poland ABSTRACT It is shown that the reachability and controllability of positive 2D linear systems are not invariant under the state-feedbacks. By suitable choice of the state-feedbacks the unreachable positive 2D Roesser model can be made reachable and the controllable positive 2D Roesser model can be made uncontrollable. Key Words: reachability, controllability, positive 2D Roesser model, state-feedback. mb2-1 Anticipatory 1D and 2D linear systems Authors: Kaczorek T., Warsaw Technical University, Poland ABSTRACT Notions of anticipatory systems for discrete-time and continuous-time 1D linear systems and 2D discrete linear systems are introduced. A discrete-time system is called anticipatory if its state vector and output vector depend on the future values of inputs. A continuous-time system is called anticipatory if its state vector and output vector depend on the derivatives of inputs. Necessary and sufficient conditions for the anticipation of singular discrete-time and continuous- time 1-D linear systems are established. It is shown that the discrete-time system obtained by discretisation from continuous-time one is anticipatory for any value of the discretisation step if and only if the continuous-time system is anticipatory. Necessary and sufficient conditions for the anticipation of the singular 2D Roesser model are established. Key Words. 1D and 2D anticipatory systems, Roesser model, dicretisation. mb2-2 A new approach to estimate controllable and recoverable regions for systems with state and control constraints Authors: Yfoulis A.C., UMIST, United Kingdom Muir A., UMIST, United Kingdom Wellstead E.P., UMIST, United Kingdom ABSTRACT In this paper the problem of estimating controllable and recoverable regions for classes of nonlinear systems in the presence of uncertainties, state and control constraints is considered. A new computational technique is proposed based upon a ray-gridding idea in contrast to the usual gridding techniques. The new technique is also based on the positive invariance principle and the use of Piecewise Linear (PL) Lyapunov functions to generate polytopic approximations to the controllable/recoverable region with arbitrary accuracy. Various types of stabilising controllers achieving certain trade-o s between robustness, performance and safety, while respecting state and control constraints, can be easily generated. The technique allows the approximation of nonlinear systems via piecewise linear uncertain models which reduces the conservatism associated with linear uncertain models. Key Words. Controllable region, recoverable region, PL-Lyapunov functions. mb2-3 The reduced order Luenberger observer and its relation to the full-state observer Authors: Alexandridis A., University of Patras, Greece ABSTRACT Abstract – The relation between the reduced-order Luenberger and the full-order state observer is considered. In particular, it is proved that for a completely observable linear system, one can always design a full-order state observer which is dynamically equivalent to any arbitrarily selected reduced-order Luenberger observer. Keywords – Observers, Linear systems, State estimation. mb2-4 Robust Gain and Phase Margins for Systems with Parametric Uncertainty Authors: Tan N., University of Sussex, United Kingdom Kaya I., University of Sussex, United Kingdom ABSTRACT Gain and phase margins are two important frequency domain specifications which are widely used for controller design. In this paper, a procedure is given for computing the robust gain and phase margins of systems with an uncertain transfer function by using the 2q-convex parpolygonal value set of polynomials with affine linear uncertainty. An example is included to illustrate the benefit of the method presented. Keywords: Uncertain systems; Nyquist envelope; Robust gain margin; Robust phase margin mb2-5 MB3 Robust Control Robust Design with Stability Preserving Maps Authors: Djaferis E. T., University of Massachusetts, USA ABSTRACT It has recently been shown that matrix Stability Preserving Maps (SPMs) play an important role in robust stabilization. They can be used to provide a different characterization for the existence of a fixed order controller that robustly stabilizes a plant family. Not only do these maps give a different perspective into the problem, but, stability preserving map tests have been developed that form the basis of robust controller design procedures. Results have been reported for plant families that either consist of a finite number of systems or can be expressed by transfer function models that. involve real parameter uncertainty. In this paper we develop additional stability preserving map tests. We also demonstrate how these tests lead to robust stabilization techniques and apply the methodology to a number of examples. Key Words. Linear systems, stability, robust design mb3-1 A Hoo design procedure for position tacking control of current-fed induction motors Authors: Chiaverini Stefano, Universita degli Studi di Cassino, Italy Fusco Giuseppe, Universita degli Studi di Cassino, Italy ABSTRACT This paper deals with robust stability analysis of polynomials where uncertain coefficients are polynomic functions of the second order of interval parameters. The method consists in determination of a convex hull overbounding the value set of such a family and using Zero Exclusion Theorem. An arbitrary stability region can be chosen. Presented method states only sufficient condition of robust stability due to nonconvexity of the value set. Both computational and graphical way of using this method are possible. The computational efficiency of presented method and more general method based on Sign-decomposition is compared. mb3-2 Robust Stability of Polynomials with Polynomic Structure of Coefficients Authors: Husek P., Czech Technical University, Czech Republic Dvorakova R. - Czech Technical University, Czech Republic ABSTRACT A robust controller, facilitating roll aircraft manoeuvres without affecting the respective sideslip attitude, is designed for the case of the lateral motion of an aircraft with actuator failure. To handle the issue the robust input output triangular decoupling technique is applied to the lateral motion dynamics of the aircraft. The condition under which the problem is solvable via state feedback appears to be generically true . The general form of the robust static decoupling controllers, as well as the general form of the resulting triangular decoupled closed loop system, are derived. Simulation are derived for a four engined executive jet aircraft. Keywords. robust stability, polynomials, polynomic uncertainty, value set mb3-3 Robust Control of the Lateral Motion of an Aircraft with Actuator Failure Authors: Skarpetis M., University of Thessaly, Greece Koumboulis F., University of Thessaly, Greece ABSTRACT Abstract. A robust controller, facilitating roll aircraft manoeuvres without affecting the respective sideslip attitude, is designed for the case of the lateral motion of an aircraft with actuator failure. To handle the issue the robust input output triangular decoupling technique is applied to the lateral motion dynamics of the aircraft. The condition under which the problem is solvable via state feedback appears to be generically true . The general form of the robust static decoupling controllers, as well as the general form of the resulting triangular decoupled closed loop system, are derived. Simulation are derived for a four engined executive jet aircraft. Key Words. Actuator failure, Flight Control, Robust Control, I/O Triangular Decoupling. mb3-4 MC1 Process Control Transition Control using a locally linearized reference system model predictive controller Authors: Oliveira-Lopes C. L. - Lehigh University, USA Georgakis C., Lehigh University, USA ABSTRACT This paper introduces a Reference System based Model Predictive Controller to the nonlinear transition control problem. The proposed control strategy is based on an online model reference evaluation, called reference system, using a factorization of a locally linearized version of the nonlinear model. The output feed- back problem is addressed using an lp norm as a performance control measurement. The online implementation of the algorithm requires only the solution of an LP or QP problem. By evaluating locally the achievable closed-loop performance, the RS- MPC effects the transition between steady states with enhanced performance over a wide operating region without the necessary retuning of standard MPC algorithms. A chemical reactor example is presented to illustrate the control application. Keywords. MPC, Transition Control, Reference System. mc1-1 Disturbance Rejection with simultaneous Decoupling of a Distillation Column Authors: Panagiotakis G., National Technical University of Athens, Greece Paraskevopoulos P., National Technical University of Athens, Greece Boretos G., National Technical University of Athens, Greece ABSTRACT The problem of input.... output Decoupling with simultaneous Disturbance Rejection (DRD) of a Distillation Column is studied. The results reported are first in the field due to the fact that the combined DRD problem is resolved for the case where time delays introduced in the column are taken into account. The controller derived is realistic to implement, while it yields a significant improvement in the system's performance over other reported distillation column studies. Key Words. Multivariable Control, Time.... Delay Systems, Decoupling and Disturbance Rejection, Linear Systems, Distillation Column Control. mc1-2 Active Control of Combustion Instabilities via Hybrid Resetting Controllers Authors: Haddad M. W., Georgia Insitute of Technology, USA Kablar A. N. - Georgia Insitute of Technology, USA Chellaboina V. - University of Missouri, USA ABSTRACT In this paper we propose an energy ow resetting control architecture as a means for achieving enhanced energy dissipation in combustion systems. The overall framework is based on a hybrid controller architecture wherein the closed-loop dynamical system is characterized by impulsive differential equations. The proposed framework is used to design high-performance hybrid controllers for suppressing thermoacoustic oscillations in combustion chambers by eficiently dissipating modal system energy. Key Words. Hybrid resetting controllers, thermoacoustic instabilities, combustion control, energy ow, impulsive dynamical systems. Key Words. Hybrid resetting controllers, thermoacoustic instabilities, combustion control, energy ow, impulsive dynamical systems mc1-3 Low-rank Fired Boilers Monitoring by Applying Hybrid Models Authors: Hadjiski M., University of Chemical Technology and Metallurgy,Sofia, Bulgaria Nikolov M., Start Engineering JSCo, Bulgaria Dukovski S., Start Engineering JSCo, Bulgaria Drianovski G., Start Engineering JSCo, Bulgaria Tamnishki E. - Start Engineering JSCo, Bulgaria ABSTRACT In the paper some practical aspects of hybrid modeling application in power plant monitoring are under consideration. In the case of low-rank lignite firing, a numerous problems arise, due to the lack of measurements of the key process variables such as coal main characteristics – mineral composition, caloricity, moisture; flame characteristics – geometry; space distribution of particles, speeds, chemical contents of gases, temperature, pressure; the properties of coal dust after milling system. Inferred variables and hybrid modeling based monitoring of the hard measurable variables is discussed. In the paper the problems with combination of direct and inferred model's input data are considered. The aggregation of different kind of mathematical models is applied. A number of important cases are presented by applying the inference approach and hybrid modeling: (i) the space position of the flame in combustion chamber, (ii) indirect estimation of the main characteristics of the fired coal, (iii) determination of the admissible control range of the steam boilers. Some of the proposed schemes for monitoring have been applied in 210 MW boilers. The rest of them give promising simulation results and after certain additional engineering will be implemented too. Key Words. hybrid modeling, inference measurement, low-rank lignite, monitoring, steam boiler mc1-4 Optimal Control of Parallel Batch Reactors Authors: Boshnakov K., University of Chemical Technology anf Metallurgy, Bulgaria Hadjiski M., University of Chemical Technology anf Metallurgy, Bulgaria ABSTRACT In this paper joint control and optimization problems of parallel processing batch reactors are considered. The specific problem addressed is the on-line scheduling of oxidation reactors in Dymethyl terephthalate (DMT) producing plant. Three level hierarchical control system is proposed to coordinates off-line optimization of batch profiles and schedules with on-line multilevel control. A reactive layered multifunctional scheduler is developed to react adequately to the batch processes variability as well as to the operations in the downstream and upstream stages of the whole plant. Results of computer simulation tests as well as some partially applications are presented. Key Words. Batch process, control, optimization, oxidation, reactor, scheduling. mc1-5 MC2 Motor Control Sliding mode based outer control loop for sensorless speed control of permanent magnet synchronous motor Authors: Vittek J., University of Zilina, Slovak Republic Altus J., University of Zilina, Slovak Republic Dodds J.S., University of East London, United Kingdom Perryman R. - University of East London, United Kingdom ABSTRACT To improve robustness to parameter uncertainties and external load torque of shaft sensorless electrical drives employing permanent magnet synchronous motors (PMSM) with forced dynamics a new more complex control system is presented. The original control structure consists of the inner loop, which is stator current control loop and the middle loop, which is shaft sensorless speed control loop based on the forced dynamics. This control structure is completed with the outer loop, based on the sliding mode control (SMC) principles. The forced dynamics control, as well as converting the non-linear PMSM into a linear element, offers higher robustness than conventional shaft sensorless speed control methods. Based on feedback linearisation a first order linear closed-loop response to speed demands with a user specified time constant is obtained. Simulation and experimental results presented show good correspondence with theoretical predictions. Key Words: Synchronous motor control, observers, sliding-mode control, variable-structure control, cascade control, non-linear systems, feedback linearisation. mc2-1 Observer-Based Sliding Mode Control of Synchronous Generator Authors: Utkin V. - The Ohio-State University, USA Loukianov A., CINVESTAV, Unidad Guadalajara, Mexico Canedo J., CINVESTAV, Unidad Guadalajara, Mexico Ramirez J., CINVESTAV, Unidad Guadalajara, Mexico Cabreva-Vazquez J. - CINVESTAV, Unidad Guadalajara, Mexico ABSTRACT This paper describes an application of the block control and variable structure control techniques to form a stabilizing controller for an synchronous generator. This combined approach enables the inherent nonlinearities of the generator to be compensated and high level external disturbances to be rejected. Also, the control system utilizes a nonlinear observer for estimation of the mechanical torque and rotor fluxes. Keywords. Synchronous generator, stability, variable structure control, observers. mc2-2 Integrated Design of Robust Internal-Loop Compensator and Synchronizing Motion Controller for Twin-Servo Systems. Authors: Kim B. K., POSTECH, Korea Chung W. K., POSTECH, Korea Choi H.-T., Hanyang University, Korea Suh I. H., Hanyang University, Korea ABSTRACT In this paper, we propose an integrated design method of robust internal-loop compensator and synchronizing motion controller to cancel out skew motion of twin-servo system caused by different dynamic characteristics of two driving systems. And also, we focus on the modeling of the twin-servo system and propose its network representation. The proposed control method consists of separate feedback motion controller of each driving system and skew motion compensating controller between two systems. Robust tracking controller based on robust internal-loop compensator is proposed as a separate motion controller and its disturbance attenuation property is shown. Skew motion compensation scheme is also designed to maintain the synchronizing motion during high speed operation, and the stability of the whole closed loop system is proved based on passivity theory. Finally, experimental results are shown to verify control performance. Key Words. Twin-servo system, network representation, synchronizing motion control, robust internal-loop compensator. mc2-3 PID Control for Induction Motors in Field Coordinates Authors: Koumboulis F., University of Thessaly, Greece Boukas T., University of Thessaly, Greece Mertzios B. - Democritus University of Thrace, Greece ABSTRACT The problem of flux and speed control of induction motors modelled in field coordinates, is studied. First, a P-I controller is applied that satisfies the requirement of current command following. Additionally a P-D controller is applied. The P-D controller provides flux and speed command following with simultaneous rejection of the load torque. Finally, a discrete observer being suitable for on line implementation is proposed. The present results are illustrated via simulation for a M3541 Baldor industrial motor. Key Words. AC-motors, PID Control, Nonlinear Systems, Speed/Position Control, Disturbance Rejection mc2-4 Robust Position/Speed Control for Permanent Magnet DC Motors via P-D Feedback Authors: Koumboulis F., University of Thessaly, Greece Skarpetis M., University of Thessaly, Greece Mavridis C., University of Thessaly, Greece ABSTRACT For a permanent magnet DC motor the design goal of perfect position/speed control with simultaneous load torque rejection is studied, using a P-D feedback law. The problem is proved to be always solvable. The P-D feedback law solving the problem is determined. Stability properties and robustness are investigated. The above results are illustrated via simulation for a 75 watt DC motor. Key Words. DC motor, linear systems, disturbance rejection, position control, speed control, robust control. mc2-5 TA1 Hybrid Systems II (invited) Organized by: Pappas G. - University of Pennsylvania, USA Lygeros J., University of California at Berkeley, USA Antsaklis P., University of Notre Dame, USA Stabilizing Supervisory Control of Hybrid Systems based on Piecewise-Linear Lyapunov Functions Authors: Koutsoukos X., University of Notre Dame, USA Antsaklis P., University of Notre Dame, USA ABSTRACT In this paper, the stability of discrete-time piecewise linear hybrid systems is in-vestigated using piecewise linear Lyapunov functions. In particular, we consider switched discrete-time linear systems and we identify classes of switching sequences that result in stable trajectories. Given a switched linear system, we present a systematic methodology for computing switching laws that guarantee stability based on the matrices of the system. In the proposed approach, we assume that each individual subsystem is stable and admits a piece-wise linear Lyapunov function. Based on these Lyapunov functions, we compose "global" Lyapunov functions that guarantee stability of the switched linear system. A large class of stabilizing switching sequences for switched linear systems is characterized by computing conic partitions of the state space. ta1-1 Minimum-Time Reachability for Timed Automata Authors: Niebert P., VERIMAG, France Tripakis S., VERIMAG, France Yovine S. - VERIMAG, France ABSTRACT The problem of minimum-time reachability for timed automata is: given an automaton, and initial state q0 and a target state qf , find whether a run from q0 to qf exists, and if yes, a minimum time run. We show that this problem can be solved by examining acyclic paths in a forward reachability graph generated on-the- y from the timed automaton. Based on this result, we then propose three algorithms with different complex- ities. ta1-2 Analysis of Controlled Hybrid Processing Systems based on Approximation by Timed Automata using Interval Arithmetic Authors: Stursberg O., University of Dortmund, Germany Kowaleski S. - University of Dortmund, Germany ABSTRACT This contribution describes an approach to investigate reachability properties for a class of controlled hybrid systems. The continuous dynamics of these so-called Switched Continuous Systems (SCS) is selected by the discrete output of a logic controller. While reachability analysis is in general undecidable for this class of systems, the analysis is known to terminate for the class of Timed Automata (TA). In order to make reachability analysis amenable to the control structure, we propose an approximating algorithm to convert a SCS into a TA. Different modifications and extensions of the procedure are given and the approach is illustrated by the application to a chemical reaction system. ta1-3 Parameter Synthesis in Robot Motion Planning using Symbolic Reachability Computations Authors: Lafferriere G. - Portland State University, USA Pappas G. - University of Pennsylvania, USA Schneider G., VERIMAG, France Yovine S., VERIMAG, France ABSTRACT A well known problem in robotics is the motion planning problem in the presence of static obstacles. The trajectory of the robot must satisfy a linear differential equation as well as possible input and state constraints. In this paper, we explore the use of symbolic reachability algorithms to decide whether the motion planning problem is feasible or not. In the case where it is feasible, it computes a feasible nominal input pro le satisfying all system constraints. Our algorithm is based on quantifier elimination techniques in the ordered field of the reals, which have been recently applied to compute the reachable space for classes of linear hybrid systems. ta1-4 TA2 Advances in Linear Systems II Selective Invariance in Multivariable Control Systems with Internal Models Authors: Lyubchik L., Kharkov State Polytechnic University, Ukraine Kostyuk O., Kharkov State Polytechnic University, Ukraine ABSTRACT The problem of disturbance decoupling in multivariable control systems is considered. It has been shown that different two-degree-of-freedom control structures used for unmeasurable disturbance estimation and compensation may be treated as a particular case of a general Inverse Model Control approach. The decomposition of the problem into the separate disturbance state and model estimation is suggested. Moreover the connection between inverse model design problems and unknown input observer theory has been established in order to give a practical way to inverse model parameterization and design. The properties of closed- loop system with model-based controllers have been also investigated with the aim of attainable accuracy estimation. ta2-1 Quadratic Characterization and Use of Output Stabilizable Subspaces Authors: Castelan B.E., LCMI/DAS/UFSC, Brazil Llanos Villareal R. E., LCMI/DAS/UFSC, Brazil Hennet J.-C., LAAS, France ABSTRACT The study is based on the characterization of Output Stabilizable (C,A,B)- invariant subspaces through two coupled quadratic stabilization conditions. The paper shows the equivalence between the existence of a solution to this set of conditions and the possibility to stabilize the system by output feedback. An algorithm and a numerical example are provided to illustrate the approach. Key Words. Output feedback, geometric approach, quadratic stabilizability, LMIs. ta2-2 Spectral Characterization of d.z. of Linear Systems Authors: Karcanias N., City University, United Kingdom Tamvaklis N., Athens, Greece ABSTRACT The classical result of Gilbert on the testing of con- trollability based on the Jordan canonical description is extended here by providing a new characteriza- tion of input decoupling zeros based on the properties of appropriate Piecewise Arithmetic Progression Se- quences defined on spectral matrices determined from the Jordan canonical description. For any eigenvalue for which there is loss of modal controllability the de- grees of the corresponding decoupling zeros are de- fined. The results given here for input decoupling zeros have their equivalent statement for the case of output decoupling zeros. ta2-3 Direct Solution of Continuous Time Singular Systems Based on the Fundamental Matrix Authors: Mertzios B. - Democritus University of Thrace, Greece ABSTRACT The fundamental and the transition matrices of the continuous-time generalized state-space system are defined. Then the solution of the generalized state-space model is given in terms of the fundamental matrix directly for the given system, without applying any decomposition in fast and slow subsystems. The proposed solution is actually a generalization of the solution of the regular state-space equation and provides insight for the particular properties of the generalized systems. The set of admissible initial conditions is directly determined from the solution and the decomposition of the solution into two orthogonal subspaces easily results by applying orthogonal operators. The fundamental and the transition matrices may be calculated in terms of the system's matrices via algebraic recursive algorithms. Key Words. Singular systems, generalized systems, fundamental matrix, transition matrix. ta2-4 TA3 Adaptive Control Continuous-Time Self-Tuning Controller Authors: Bobal V., Brno University of Technology, Czech Republic Dostal P., Brno University of Technology, Czech Republic Kolomaznik K., Brno University of Technology, Czech Republic ABSTRACT A self – tuning controller algorithm has been derived in this paper. The process is identified by the regression (ARX) continuous – time model using the recursive least squares method (RLSM) with applied directional forgetting. The recursive parameter estimates of the continuous – time model (differential equation) are used to controller synthesis. Controller synthesis is designed on the basis of pole – placement (assignment) method. The algorithm is suitable for the automatic setting of analog controllers for deterministic processes or the adaptive control of stochastic and nonlinear processes without or with time delay. One modification of the controller has been verified by computer simulation. ta3-1 Direct adaptive predictive control using subspace identification in Laguerre domain in the presence of constraints Authors: Huzmezan M., University of British Columbia, Canada Dumont A.G. - University of British Columbia, Canada ABSTRACT The classic way to control a system, in a model based framework, is to obtain a model of the system and then to use it for the design of a controller. For the class of systems characterized by a large number of inputs and outputs, such as for the cross direction control of a paper machine, we require a reduced computational time to produce the controller parameters. Our solution to this problem is a direct adaptive predictive controller which operates in the Laguerre shift operator domain and replaces the system identification step together with the calculation of the predictive controller parameters (controller that additionally contains input and output constraints) by: 1) a least squares solution, 2) two simple linear algebra operations (QR decomposition and a singular value decomposition) of a matrix constructed from input and output measurements of the unknown system and 3) a quadratic program optimization or another least squares problem. The modeling step is accomplished in a subspace identfication fashion. The resulting algorithm provides major computational savings due to the reduced dimension of the system matrices together with the absence of a specific state space model. ta3-2 On the Performance of Multimodel Adaptive Control Authors: Karimi A., Sharif University of Technology, Iran Motee N., Sharif University of Technology, Iran ABSTRACT The performance of multimodel adaptive control based on switching and tuning will be studied via several simulation examples for a exible transmission system. The effects of some design parameters like number of fixed and adaptive models and forgetting factor will be considered. The performance of a recently developed parameter adaptation algorithm based on closed loop output error will be compared with the classical least squares prediction error algorithm in the multimodel adaptive control. ta3-3 Predictive Transient Control of EGR/VTG for Internal Combustion Engines Authors: Hafner M., Darmstadt University of Technology, Germany ABSTRACT Modern engine control systems basically use stationary curves and 3D maps in order to control internal combustion (IC) engines. Future legislative emission restrictions, however, will require an additional optimization of the transients between different static operating points. This contribution presents a model based predictive optimization of transient EGR (exhaust gas recirculation) and VTG (Turbocharger with variable turbine geometry) control settings between two operating points. Basic tran-sient functions, which are piecewise linear, are introduced. The parameters of these transient functions are then optimized concerning the emissions- consumption trade-off. The model base is realized by fast neural networks. A DSP-based process computer system allows a fast application of the optimization tool at the engine test stand. ta3-4 New Approach of Adaptive Automatic Load Shedding Authors: Terzija V., Universitaet des Saarlandes, Germany Koglin H.-J., Universitaet des Saarlandes, Germany ABSTRACT In the paper a new approach of adaptive automatic load shedding, a procedure for protecting electric power systems from dynamic instability and frequency collapse is presented. It is consisted of two main stages. In the first stage the frequency and the rate of its change are estimated by nonrecursive Newton Type Algorithm and Least Error Squares Method. In the second stage the magnitude of disturbance, i.e. the difference between generated and consumed active power is estimated by applying the simplest form of generator swing equation. Results of multimachine test system computer simulations are presented. ta3-5 TB1 Sensor-Based Control for Robotic Systems (invited) Organized by: Tsakiris D., ICS-FORTH, Greece Solutions for Visual Control of Motion: Active Tracking Applications Authors: Barreto J., University of Coimbra-Polo II, USA Batista J., University of Coimbra-Polo II, USA Araujo H., University of Coimbra-Polo II, USA ABSTRACT This paper deals with active tracking of 3D moving targets. The performance and robustness in visual control of motion depend on the vision algorithms and the control structure where dynamical aspects can not be neglected. Visual tracking is presented as a regulation control problem. Both system architecture and controller design are discussed. The performance of visually guided systems is substantially deteriorated by delays in the control loop. Interpolation is used to cope with visual processing delay. Model predictive control strategies are proposed to compensate for the mechanical latency and improve the global system performance. tb1-1 Robot Formations: Learning Minimum Length Paths on Uneven Terrain Authors: Hristu D., University of Maryland, USA ABSTRACT We discuss a prototype problem involving terrain exploration and learning by formations of autonomous vehicles. We investigate an algorithm for coordinating multiple robots whose task is to find the shortest path between a fixed pair of start and target locations, without access to a global map containing those locations. Odometry information alone is not suficient for minimizing path length if the terrain is uneven or if it includes obstacles. We generalize existing results on a simple control law, also known as \local pursuit", which is appropriate in the context of formations and which requires limited interaction between vehicles. Our algorithm is iterative andconverges to a locally optimal path. We include simulations and experiments illustrating the performance of the proposed strategy. tb1-2 Using Fast Statistical Dynamic Contours for Grasping Occluding Contours Authors: Perrin D., University of Minnesota, USA Masoud O., University of Minnesota, USA Smith C., University of Colorado at Denver, USA Papanikolopoulos N., University of Minnesota, USA ABSTRACT Object grasping is one of the basic functions required for many manipulator tasks. In particular, the grasping of unknown objects is often a desired functionality in manipulator system applications ranging from space exploration to factory automation. Due to the amount of object and environment data typically required to execute an unknown object grasp, computer vision is the sensor modality of choice. This paper presents a method for the automatic determination of plausible grasp axes on unknown objects using an eye-in-hand robotic system and a novel deformable contour model. The system finds potential grasp point pairs, ranks all the possible pairs/axes based upon measurements taken from the con-tour, and executes a vision-guided grasp of the object using the highest ranked grasp point pair to determine the gripper alignment constraints. Key Words. Robotic Grasping, Statistical Dynamic Contours, Eye-in-Hand Robotic Sys-tems. tb1-3 Corridor Following by Mobile Robots Equipped with Panoramic Cameras Authors: Tsakiris D., ICS-FORTH, Greece Argyros A., ICS-FORTH, Greece ABSTRACT The present work considers corridor–following maneuvers for nonholo-nomic mobile robots, guided by sensory data acquired by panoramic cameras. The panoramic vision system provides information from an environment with textured walls to the motion control system, which drives the robot along a corridor. Panoramic cameras have a 360 visual field, a capability that the proposed control methods ex-ploit. In our sensor–based control scheme, optical flow information from several distinct viewing directions in the entire field of view of the panoramic camera is used directly in the control loop, without the need for state reconstruction. The interest of this lies in the fact that the optical flow information is not sufficient to reconstruct the state of the system, it is however sufficient for the proposed control law to accomplish the desired task. Driving the robot along a corridor amounts to the asymptotic stabi-lization of a subsystem of the robot's kinematics and the proposed control schemes are shown to achieve this goal. tb1-4 A New Partitioned Approach to Image-Based Visual Servo Control Authors: Corke P., CSIRO Manufacturing Science & Technology, Australia Hutchinson S., Univ. of Illinois at Urbana-Champaign, USA ABSTRACT In image-based visual servo control, since control is effected with respect to the image, there is no direct control over the Cartesian velocities of the robot end effector. As a result, trajectories that the robot executes, while producing image trajectories that are pleasing, can be quite contorted in the Cartesian space. In this paper we introduce a new partitioned approach to visual servo control that overcomes this problem. In particular, we decouple the z-axis rotational and translational components of the control from the remaining degrees of freedom. Then, to guarantee thatallfeatures remain in the image throughout the entire trajectory, we incorporate a potential function that repels feature points from the boundary of the image plane. We illustrate our new control scheme with a variety of results Tb1-5 TB2 Estimation and Identification Spectral Factorization by Means of Discrete Fourier Transform Authors: Jezek J., Academy of Sciences of the Czech Republic, Czech Republic Hromcik M., Academy of Sciences of the Czech Republic, Czech Republic Sebek M., Academy of Sciences of the Czech Republic, Czech Republic ABSTRACT A new algorithm is presented for the spectral factorization of a two- sided symmetric polynomial. This algorithm being combined with digonalization techniques for polynomial matrices can also be utilized in the multivariable case to calculate the spectral factor of a discrete-time para-Hermitian polynomial matrix. The proposed method is based on the discrete Fourier transform theory (DFT) and its relation to the Z-transform. Involving DFT into the computations brings high efficiency and reliability due to desirable numerical properties of the fast Fourier transform algorithm standing behind. The paper also includes an illustrative numerical example and discusses the numerical properties of the suggested routine with respect to other existing techniques. tb2-1 State Estimation with Uncertain Parametric Models Authors: Sayed A., UCLA, USA ABSTRACT This paper develops robust estimation algorithms for state-space models that are subject to bounded parametric uncertainties. Compared with existing robust filters, the new filters perform data regularization rather than de-regularization and they do not require existence conditions. The resulting filter structures also turn out to be similar to various (time- and measurement- update, prediction, and information) forms of the Kalman filter, albeit ones that operate on corrected parameters rather than on the given nominal parameters. Keywords: Estimation, parametric uncertainty, set-valued estimation, Kalman filtering, Hoo filtering, guaranteed-cost design, steady-state filter, regularized least-squares. tb2-2 The Impact of Scheduled Maintenance on the failure process of Electric Rail Vehicles Authors: Stavropoulos Ch., University of Patras, Greece Fassois S. - University of Patras, Greece ABSTRACT This paper addresses the stochastic modeling and impact assessment of scheduled maintenance actions on the reliability of electric rail vehicles, the latter expressed in terms of recorded Times Between Failures (TBFs). The study is based upon historical time series data from the Athens Electric Railways and intervention analysis within a novel non-stationary Functional Series modeling framework, which allows for the modeling, scheduled maintenance impact assessment, analysis, as well as failure time prediction. The results of the study indicate that intervention models incorporating scheduled maintenance effects are significantly better than their unaccounting counterparts. Furthermore, the statistical significance of the maintenance effects is demon- strated, and reliability prediction is shown to be feasible. Key Words. Maintenance effects, stochastic reliability, failure process analysis, intervention analysis, non-stationary time series. tb2-3 Applications of Fuzzy Neural Networks with Nonlinear Consequences to System Identification Authors: Overstreet J., Polytechnic, USA Tzes A., University of Patras, Greece ABSTRACT The objective of this article is to formulate a generic Fuzzy Logic Identifier (FLI) with a neural network structure for identification purposes of nonlinear systems. This FLI extends the current limited representation of fuzzy models by modifying its consequence part as a ratio of poly- nomials of the input variable. The weights of the premise and consequence parts are tuned in an adaptive manner based on the backpropagation algorithm. The suggested scheme is applied in identifying the nonlinear aspects of fric- tion in a dcmotor micromaneuvering system. tb2-4 Primitive Target Localization and Identification Using CTFM Sonar Imaging Authors: Politis Z., University of Oxford, United Kingdom Probert P., University of Oxford, United Kingdom ABSTRACT In this paper we introduce a new method for acquiring and processing ultrasound signals for the location and identification of the typical primitives for map building - planes, obtuse angled corners, cylinders, right angled corners and edges. The transducer is a continuous wave single frequency modulated (CFTM) transmitter/receiver, not original in terms of its hardware but with little reported application in this field. Models of the echo signals received allows the feature parametrization of their range and amplitude values with respect to the distance and orientation of the target. Receiver saturation due to the large dynamic range is included in the models. Based on these models and the geometry of a re ection from plane and other targets we proved that only two measurements of the target at two distinctive positions are fulfill the minimum information requirement to localize and classify the studied targets. The proposed method was tested over a set of measurements from the five target types and the results strongly matched the theoretical implications. Applications of this method are suggested. Keywords. Acoustic sensors, geometrical modeling, CTFM sonar, mobile robots. tb2-5 TB3 Flight Control Hoo Approach to Precision Missile Guidance Authors: Savkin V. Andrey, The University of Western Australia, Australia Faruqi A. Farhan, Defence Science and Technology Organization, Australia ABSTRACT The paper addresses the precision missile guidance problem where the successful intercept criterion has been defined in terms of both minimizing the miss distance and controlling the missile body attitude with respect to the target at the terminal point. We show that the H 1 control theory when suitably modified provides as effective framework for the precision missile guidance problem. Existence of feedback controllers (guidance laws) is investigated for the case of finite horizon and non-zero initial conditions. Both state feedback and output feedback implementations are explored. Keywords. Precision missile guidance, robust control, H 1 control, optimal control, Riccati equations tb3-1 Weak Model Based Fault Detection and Identification in Flight Control Systems Authors: Golan O., Technion, Israel Institute of Technology, Israel Idan M., Technion, Israel Institute of Technology, Israel Meir R, Technion, Israel Institute of Technology, Israel ABSTRACT This paper deals with fault detection and identification (FDI) of sensor failures in an aircraft flight control system. The proposed FDI algorithm only weakly depends on a specific model of an aircraft. The advantage of such an FDI algorithm is the possible reduction in the flight control system complexity and cost due to the reduced number of redundant hardware components required to ensure safe flight operation in cases of failures. The non-mode] based approach is in particular attractive because it could provide an FDI algorithm suitable for implementation on a variety of aircraft with only minimal adjustments required when using it on a specific aircraft, thus reducing the development cost. The current paper focuses on non-distinctive sensor failures that are identified using dissimilar sensor information. The proposed FDI algorithm was favorably tested using a realistic simulation model of a small civil aircraft. Key Words. Fault detection and identification, fault tolerant flight control, Neural Networks, Wavelet Transform. tb3-2 Independent Control of the Lateral Motion of an Aircraft Authors: Skarpetis M., University of Thessaly, Greece Koumboulis F., University of Thessaly, Greece Ladopoulos T., University of Thessaly, Greece ABSTRACT The design goal of independent control of sideslip angle, roll angle and yaw angle of an aircraft is considered. To handle the issue the input-output decoupling technique is applied to the lateral motion dynamics of the aircraft. The conditions under which the problem is solvable via state feedback appears to be generically true. The general form of the static controllers, as well as the general form of the resulting decoupled closed loop system, are derived. The results has been illustrated by simulation to the data of 5th-order FPCC aircraft. Key Words. I/O Decoupling, Flight Control, Linear System, Multvariable Control tb3-3 TC1 Applied Robotics The Genetic-Connectionist Algorithm For Compliant Robotic Tasks Authors: Katic D. - Mihailo Pupin Institute, Yugoslavia ABSTRACT In this paper, a systematic connectionist controller design approach is proposed to guarantee stability and desired performance of the robotic system for compliant tasks by effectively combining genetic algorithms(GA) with neural classification and neural learning control techniques. The effectiveness of the approach is shown by using a simple and eficient decimal and binary GA optimization procedures to tune and optimize the performance of a neural classifier and controller, together with tuning of feedback controller.In order to demonstrate the effectiveness of the proposed GA approach, some compliant motion simulation experiments with robotic arm placed in contact with dynamic environment have been performed. Keywords. Genetic algorithms, Neural networks, Learning Control, Robotics. tc1-1 Neuro-Control of Force applied by a robot in fabric handling tasks Authors: Koustoumpardis N.P., University of Patras, Greece Aspragathos A.N., University of Patras, Greece ABSTRACT In this paper, a control scheme based on Neural Networks is described for handling fabrics using robots to feed automated sewing stations. Fabric handling tasks such as sewing demand regulation of the appeared forces and orientation of the fabric. The proposed control approach calculates the appropriate velocity of the robot hand holding the one end of the fabric, while a constant tensional force is applied, when the other end of the fabric is pulled by the sewing machine with an unknown velocity. The effectiveness of the proposed controller lies in the fact that it is independent from the properties of the fabric, as only the measurement of the desired tensional force applied along the fabric is necessary. Key Words. Fabric handling, Robotic Sewing, Neural Network, Force Control tc1-2 Depth Extraction from Contours by Monocular Eye-in- Hand Systems Authors: Perrin P.D., University of Minnesota, USA Smith E.C., University of Colorado at Denver, USA Papanikolopoulos N. - University of Minnesota, USA Smith E.C. - University of Colorado at Denver, USA ABSTRACT Many vision-based robotic applications either require, or can be improved by, accurate object depth measures. Several computer vision methods exist for extracting depth of features, including stereo vision, structured-light systems, and active monocular depth recovery. Previous efforts using these methods suffered from a variety of problems related to calibration and computational complexity. This paper presents a novel method for active monocular depth recovery that combines new, highly stable active deformable models (snakes) with a structured camera motion along the optical axis to produce depth estimates for all the snake control points.. In experiments with a variety of objects and depths, this method produced control point correspondences and calculated the depth of a large number of control points in the order of 1 ms. Accuracy is demonstrated by results that exhibit errors near the predicted errors when assuming a single pixel mis-measurement in control point location on the image plane. Keywords. Robotic Grasping, Statistical Dynamic Contours, Eye-in-Hand Robotic Systems. tc1-3 Fuzzy Neural Network-based Internal Model Control for DC-Motor Micromaneuvering Authors: Overstreet J., Polytechnic, USA Tzes A., University of Patras, Greece ABSTRACT The development of a Fuzzy Neural Network (FNN)-bascd Internal Model Control (IMC) scheme and its application to a dcmotor micromaneuvering system is addressed in this article. The FNN is tuned in an offline manner in order to cancel the motor's inherent nonlinear friction term. The resulting FNN is used in the feedback path, augmented by a primitive linear timeinvariant controller in the forward path. The adjustment of the linear controller's parameters relies on the IMC framework based on the premise that the system's nonlinearities have benn canceled by the FNN. The suggested controller-structure is tested in experimental studies at a dcmotor testbed to investigate its efficiency. Keywords: Fuzzy neural network, Friction compensation, DCmotor control. tc1-4 TC2 Computation Fault-Tolerant Sequence Enumerators Authors: Hadjicostis C.N., University of Illinois at Urbana-Champaign, USA ABSTRACT Modular redundancy, the traditional approach to fault tolerance, is prohibitively expensive because of the overhead in replicating the hardware. In this paper we discuss alternative techniques for fault tolerance in sequence enumerators that are implemented as linear finite-state machines (LFSM's). Our approach replaces a given LFSM with a larger, redundant LFSM that preserves the evolution and properties of the original one. The state of the larger LFSM is a linearly encoded version of the state in the original machine and allows an external mechanism to perform error detection and correction by identifying and analyzing violations of the code restrictions. In this paper, we characterize the class of appropriate redundant LFSM's and demonstrate a variety of possibilities for fault tolerance, ranging from no redundancy to full replication. Key Words: Fault tolerance, linear finite-state machines, concurrent error detection and correction. tc2-1 Improved Polynomial Matrix Determinant Computation Authors: Henrion D., LAAS-CNRS, France Sebek M., Trnka Lab. of Autom. Control, FEL CVUT, Czech Republic ABSTRACT An early result on the Smith-MacMillan form of a rational matrix is used for evaluating the degree of the determinant of a polynomial matrix using numerically reliable techniques. This allows for accurate determinant zeroing and determinant interpolation, thus improving existing numerical methods for polynomial matrix determinant computation. Key Words. Polynomial Matrix, Determinant Computation, Numerical Methods. tc2-2 An Efficient Serial Pipelined Implementation of ax+by Authors: Pekmestzi K., National Techical University of Athens, Greece Kalivas P., National Techical University of Athens, Greece Moshopoulos N., National Techical University of Athens, Greece Sifnaios I., National Techical University of Athens, Greece ABSTRACT An efficient implementation of the operation by ax + , on which the construction of second order digital filters and complex numbers multipliers is based, is presented. The quantitiesx and y are 2's complement numbers in serial form. The numbers a and b are constant coefficients in Canonical Signed Digit form (CSD) while the result is obtained in se-rial 2's complement form. The proposed scheme operates in pipeline mode with 100% hard-ware efficiency, namely, no sign extension words between successive data words are re-quired. The implementation is based on merging of two serial multipliers, which yields sig-nificant hardware reduction. Key Words. Serial multipliers, Systolic multipliers, Digital filters tc2-3 Symbolic implementation of Leverrier-Faddeev algorithm and applications Authors: Stanimirovic S.P., University of Nis, Yugoslavia Karampetakis P. N., Aristotle University of Thessaloniki, Greece ABSTRACT In this paper we propose two algorithms for the computation of the Drazin inverse, based on the Leverrier-Faddeev algorithm. These algorithms represent extensions of paper [3] and a continuation of the paper [4]. A few matrix equations which include rational matrices are solved by means of the Drazin inverse and the Moore-Penrose inverse of rational matrices. Keywords. Drazin inverse, Leverrier-Faddeev algorithm, matrix equations. tc2-4 Demonstration of Self-learning Fuzzy Logic Controller Performance in the Matlab+SimulinkTM Environment Authors: Kovacic Z., University of Zagreb, Croatia Bogdan S., University of Zagreb, Croatia Reichenbach T., University of Zagreb, Croatia ABSTRACT In this paper, we demonstrate a performance of a PD type self-learning fuzzy logic controller (SLFLC), which has been implemented as a function block for the very popular Matlab+Simulink environment. The SLFLC described in detail in [1 ] utilizes a reference model and a sensitivity model for learning of SLFLC parameters. The effectiveness of the SLFLC function block has been demonstrated on the model of a closed-loop engine speed control system provided in Matlab for demo purposes. The results show very clearly how the SLFLC brings improved performance into the selected control system example. tc2-5 TC3 Modeling, Estimation, and Control of Infinite Dimensional Systems (invited) Organized by: Demetriou M., Worcester Polytechnic Institute, USA Modelling and Control of a Thin Piezo-actuated Structure Authors: Bisegna P., Universita di Roma "Tor Vergata", Italy Caruso G., Universita di Roma "Tor Vergata", Italy Galeani S., Universita di Roma "Tor Vergata", Italy Menini L. - Universita di Roma "Tor Vergata", Italy Del Vescovo D., Universita di Roma "La Sapienza", Italy ABSTRACT Vibration damping for a thin piezoactuated cantilever plate is pursued through either purely passive or purely active control. The design is carried out by using suitable reduced order models of the coupled electro-mechanical structure. Simulation results are presented in order to evaluate the proposed control laws. Key Words Vibration damping, piezoelectric finite-elements, LQG control. tc3-1 Optimal Actuator Guidance Scheme for a 2-D Thermal Manufacturing Processing Authors: Demetriou M., Worcester Polytechnic Institute, USA Vayena O., Tufts University, USA Doumanidis H., Tufts University, USA ABSTRACT This article addresses the need for optimal actuation in distributed-parameter systems dominated by conductive heat transfer,such as in thermal processing of materials.An LQR- based approach is developed,which determines the optimal location and the power of the actuator at successive time periods,by piece-wise minimization of the quadratic performance indices corresponding to theses subintervals.This algorithm is applied to a finite dimensional representation of the temperature state and heat input distributions,yielding a suboptimal but computationally efficient heat source guidance strategy.This is shown to warrant superior temperature tracking performance over fixed —location actuation,by FEA simulations. tc3-2 Existence and Uniqueness of Solutions to a Nonlinear Nonlocal Second Order Initial-Boundary Value Problem Authors: Ackleh A., University of Louisiana at Lafayette, USA, Aizicovici S., Ohio University, USA Demetriou M., Worcester Polytechnic Institute, USA Reich S., Technion-Israel Inst. of Technology, Israel ABSTRACT In this short note we announce an existence and uniqueness result for solutions to a class of second order distributed parameter systems with sudden changes in the input term. Such systems are often encountered in exible structures and structure- uid interaction systems that utilize smart actuators. tc3-3 Degenerate Hopf Bifurcation to Multiple Regenerative Chatter Authors: Fofana M., Worcester Polytechnic Institute, USA ABSTRACT This paper deals with the application of in…nite-dimensional delay dynami-cal systems in the study of multiple regenerative chatter machining. Bifurcation equations describing the dynamics when linearized stability is lost have been derived. Two cases are considered. First, when Hopf's conditions hold, and second when one of them is violated. Key Words. Regenerative chatter, degenerate bifurcation, delay di¤erential equations. tc3-4 WA1 Control Systems with Delay Observers for a class of Nonlinear Systems with Time- Varying Delay Authors: Aggoune W., CRPHT Technoport Schlassgoart, Luxembourg Sallet G., INRIA Lorraine, France ABSTRACT In this paper, observers design for a class of nonlinear systems with time-varying delay is addressed. We use the Razumikhin approach to deduce general conditions for asymptotic convergence of the observer. These conditions are expressed in terms of the existence of a positive de nite matrix solution of a Riccati-type equation. Key Words. Observers, nonlinear systems, time delay, Riccati-type equation. wa1-1 Functional Controllability and Right Invertibility for Systems over Rings Authors: Conte G., Universita' di Ancona, Italy Perdon A. M., Universita' di Ancona, Italy ABSTRACT This paper is devoted to study the structure of linear systems with coe?cients in a ring in connection with the so-called Functional Controllability Property and the Right Inversion Problem. A geometric characterization of Functional Controllability is given and a related notion of Relative Degree is introduced. Applications to delay-differential systyems are considered. Keywords: Linear systems over ring, output reproducibility, delay-di erential systems wa1-2 Robust Analysis of Controllers for Linear Systems with Time Delay Authors: Hustak P., Technical University Brno, Czech Republic Prokop R., Technical University Brno, Czech Republic ABSTRACT The contribution deals with the robust control design for linear systems with time delays. The proposed control synthesis is based on general solutions of Diophantine equations in the ring of Hurwitz stable and proper rational functions Rps. The methodology is suitable for stable and unstable transfer functions and covers both tracking and disturbance rejection problems. Several approximations of the time delay term is investigated and compared for stable and unstable processes. Perturbations and robustness are studied through the infinity (H.... ) norm and by open loop Nyquist plots. Resulting control laws for first order systems are of a general PID type and a scalar tuning parameter influencing robustness and properties of the closed loop system was introduced. Simulations were performed in Matlab and Simulink environment. Key Words. Time-delay systems, linear approximations, robustness, PID controllers, Diophantine equations. wa1-3 A Simple Automatic Tuning Method for a Smith Predictor Authors: Kaya I., University of Sussex, United Kingdom Tan N., University of Sussex, United Kingdom ABSTRACT In this paper a new approach is presented based on relay autotuning of a plant to find parameters for its control using a Smith predictor. A Smith predictor configuration is represented as its equivalent internal model controller, IMC, which provides the parameters of the PI or PID controller to be defined in terms of the desired closed-loop time constant, which can be adjusted by the operator, and the parameters of the process model. This means that only one parameter, namely the desired closed-loop time constant, is left for tuning. The ISE criterion was used to find the filter parameter, and simple equations were obtained to tune the Smith predictor. The method is very simple and has given improved results compared with some previous approaches. Keywords: Relay autotuning, PID controller, Smith predictor, IMC Control wa1-4 Tuning Smith Predictors using Simple Formulae Authors: Kaya I., University of Sussex, United Kingdom Tan N., University of Sussex, United Kingdom ABSTRACT Good control of processes with long dead time is often achieved using a Smith predictor configuration. However, not much work has been carried out on obtaining simple tuning rules for a Smith predictor scheme. This paper develops optimal analytical tuning formulae for PID controllers in a Smith predictor configu- ration assuming perfect matching. These formulae have been obtained by carrying out repeated optimizations on the error transfer function of a Smith predictor, assuming perfect matching, to find optimal relations between the normalized gain and the remaining parameters of the controller. Then the least square fitting method was used to find the constants in the assumed formulae to fit the graphical data obtained. Some examples are given to show thevalue of the approach presented. Keywords: Predictive control; Integral performance indices; Delay compensation; PID controllers Keywords: Predictive control; Integral performance indices; Delay compensation; PID controllers wa1-5 WA2 Some LMI Problems in Control (invited) Organized by: Garcia G., LAAS-CNRS, France Bernussou J., LAAS-CNRS, France Output-reference tracking problem for discrete-time systems with input saturations and constant references Authors: Tarbouriech S., LAAS-CNRS, France Queinnec I., LAAS-CNRS, France Pittet C. - LAAS-CNRS, France ABSTRACT Nonlinear state feedback controllers are exhibited for locally stabilizing linear discrete-time systems with both saturating actuators and additive disturbances when the output must track a certain reference level. The objective is then to bring the steady-state error due to disturbances to zero by using a saturated controller and a dead-zone function. Thus, we want to determine both a stabilizing controller and a region of the state space over which the stability of the resulting closed-loop system is ensured, when the controls are allowed to saturate. wa2-1 A Multi-Objective Control Algorithm: application to a launcher with bending modes Authors: Clement B., Ecole Superieure d' Electricite, France Duc G., Ecole Superieure d' Electricite, France ABSTRACT A multi-objective control synthesis algorithm is first presented: it allows to avoid conservatism using different Lyapunov functions by combining the Youla parameterization, an observer-based structure and congruence transformations to obtain an LMI formulation. The efficiency of this approach is then tested by considering the problem of robustly stabilizing an aerospace launcher during the atmospheric flight. Key Words. Robust control, LMI optimization, Youla parameterization, Aerospace. wa2-2 Guaranteed cost and positive real uncertainty Authors: Bernussou J., LAAS-CNRS, France Garcia G., LAAS-CNRS, France Geromel J., LAC-DT, School of Electrical Eng., UNICAMP, Brazil ABSTRACT This paper presents a kind of overview of the quadratic guaranteed cost problem in face of positive real uncertainty. Continuous as well as discrete time systems are discussed to point out the main discrepancies and difficulties arising when considering the different stability conditions associated with the positive real and strongly positive real conditions. The state feedback control problem is only addressed. wa2-3 Observers interpolation for state reconstruction of Linear Parameter Varying (LPV) systems: A LMI approach Authors: Bara I., CRAN-INPL-ENSEM, France Daafouz J., CRAN-INPL-ENSEM, France Kratz F., CRAN-INPL-ENSEM, France Ragot J., CRAN-INPL-ENSEM, France ABSTRACT This paper invistigates a state observation design problem for dis- crete time linear parameter varying (LPV) systems. The main contribution of this paper consists in providing an interpolation scheme to build the LPV observer. We show that an appropriate choice of the interpolation functions allow to use available quadratic stability conditions to design an LPV observer. Key Words. LPV systems, LPV Observers, Interpolation, Quadratic stability. wa2-4 Synthesis of a non-integer control loop using performance contours Authors: Pommier V., Universite Bordeaux I, France Oustaloup A., Universite Bordeaux I, France Lanusse P., Universite Bordeaux I, France ABSTRACT The article proposes a method to design a controller ensuring dynamic behavior of a closed- loop control. Dynamic performance is, in the time domain, the first overshoot of the step response, and the damping ratio and the natural frequency of its dominant oscillatory mode. Dynamic performance is quantified, in the frequency domain, by two contours called "performance contours" and the open-loop gain crossover frequency. The first contour is the Nichols chart magnitude contour which can be considered as an iso-overshoot contour. The second contour, whose construction and analytic expression are given in this article, is a new contour defined in the Nichols plane and parameterized by the damping ratio. The proposed method uses complex non-integer (or fractional) differentiation to compute a transfer function whose open-loop Nichols locus tangents both performance contours, thus ensuring stability margins (or stability degree). Key words: Dynamic behavior, Stability margins, Overshoot, Damping ratio, Fractional differo- integration wa2-5 WA3 Robotic Manipulators On the Kinematics and Dynamics of Dual-Gripper Robot Manipulator Authors: Yih T., University of Texas at Arlington, USA Shiakolas P., University of Texas at Arlington, USA Eluri B., University of Texas at Arlington, USA Burks B., Providence Group Inc., Thompson B., RedZone Robotics, Inc. ABSTRACT A dual-gripper Remote Tool Delivery (RTD) system has been developed to retrieve radioactive wastes from underground storage tanks with internal structural members. The RTD system is equipped with two grippers at both ends of the system. A vertical translation mechanism (VTM) is added which enables the vertical lifting motion of the system. The vertical movement can be processed with each gripper operating on a separate structural member. The dual-gripper design and inclusion of the VTM distinguish the RTD system from other ordinary robotic systems. These special features provide greater dexterity and flexibility; yet, increase the complexity in modeling and analysis. There are four possible operating configurations for the RTD system. The first configuration is that gripper 1 grasps the structural member in the tank while gripper 2 is free to move in space to perform designated task. In other occasions, it is possible that gripper 2 grasps the structural member and gripper 1 performs the necessary task. These two configurations typify the RTD system as an open-chain robotic system. It is also possible that both grippers grasp separate or the same structural members simultaneously. This exemplifies the RTD system as a closed-chain mechanism. The kinematics, dynamics and simulation of the open-chain robotic configurations are investigated in this paper. Key Words. Dual-Gripper robot manipulator, Kinematic modeling, Kinematics, Dynamics, Simulation. wa3-1 Robotic Calibration Issues: Accuracy, Repeatability and Calibration Authors: Conrad K., University of Texas at Arlington, USA Shiakolas P., University of Texas at Arlington, USA Yih T., University of Texas at Arlington, USA ABSTRACT The groundwork for a contact calibration methodology using a touch probe is developed for an articulated robot arm. This solution is framed within current calibration and metrology issues in robotics based upon the kinematical mechanical design of a serial link manipulator. Accuracy, repeatability, and resolution are explored and a simplistic approach is taken. This exercise is intended to lay the groundwork for exploring the feasibility of integrating a commercial product such as a force sensor or touch trigger probe on the end of a robot arm. Candidate processes and/or applications are identified. Findings indicate that an in-process contact calibration methodology that is accurate, repeatable, and cost effective would be a desirable solution. Key Words. Robotic accuracy, repeatability, calibration, resolution wa3-2 Reduced-Order Model Matching Control Design for Gantry Robots Authors: Yang X., Georgia Institute of Technology, USA Taylor D., Georgia Institute of Technology, USA ABSTRACT An important application of gantry robots is circuit board assembly, a chal-lenging task involving rapid point-to-point motions that tend to induce structural vibrations. Attempts to suppress such vibrations through model-based controller design must take into account the variation of the flexible dynamics with respect to placement head position. To circumvent the time-varying configuration-dependent mass distribution property of the flexible dynamics, this paper explores the potential of a controller design based instead on the rigid dynamics. This reduced-order approach to controller design is recommended for gantry robots with relatively sti .beams, since it o .ers an appropriate compromise between modeling/implementation requirements and performance potential. The proposed reduced-order controller is designed using a model- matching formulation to adjust the transient response, and an integral e .ect is included to reject friction force disturbances for satisfactory steady-state response. The reduced-order model matching controller has been implemented and tested on a prototype gantry robot. The experimental results confirm the viability of the new design and show its superiority over the more traditional PID controller. Keywords: Gantry robots, flexible beams, structural vibration, point-to-point motion, reduced- order control, model matching control. wa3-3 WB1 Mobile Robotics Dynamic Motion Planning for Mobile Robots Using Potential Field Method Authors: Ge S.S., National University of Singapore, Singapore Cui Y.J., National University of Singapore, Singapore ABSTRACT The potential field method is widely used for autonomous mobile robot path planning due to its elegant mathematical analysis and simplicity. However, most researches were focused on solving the motion planning problem in a stationary environment, where both targets and obstacles are stationary. This paper proposes a new potential field method for motion planning of mobile robots in a dynamic environment where the target and obstacles are moving. Firstly, the new potential function and the corresponding virtual force are defined. Then, an on-line motion planning algorithm based on the new potential field method is presented. Finally, computer simulation is used to demonstrate the effectiveness of the dynamic motion planning scheme based on the new potential field method. Keywords: Potential Fields, Motion Planning, Moving Obstacle Avoidance wb1-1 Experimental comparison of control laws for unicycle - type mobile robots. Authors: Kim B., Georgia Institute of Technology, USA Tsiotras P., Georgia Institute of Technology, USA ABSTRACT Mobile robots offer a typical example of a system with a nonholonomic constraint. Many control laws have been developed for stabilizing these systems. One of the main issues with these controllers is that they are usually based on kinematic relations only and do not include the dynamics. Moreover, additional factors like quantization, noise and delay may be present that make stabilization more difficult. Comparing the characteristics and the performance of these controllers using an experimental testbed is therefore of great interest. In this paper, we use a Khepera robot to perform these experiments and compare several controller proposed in the literature. Key Words. Nonholonomic systems, nonlinear control, mobile robots. wb1-2 Experiments with a Team of Miniature Robots Authors: Papanikolopoulos N., University of Minnesota, USA Stoeter A.S., University of Minnesota, USA Rybski P., University of Minnesota, USA Gini M., University of Minnesota, USA Hougen F.D., University of Minnesota, USA Erickson M., University of Minnesota, USA ABSTRACT This paper presents several experiments with a large team of heterogeneous robots. The team consists of two types of robotic agents. The first type is a larger, heavy-duty robotic platform, called the \ranger." Rangers are used to transport, deploy, and supervise a number of small, mobile sensor platforms called \scouts," the second type of robotic agent. In an example scenario, the scouts are deployed into an office/lab environment, navigate towards dark areas, and position themselves to detect moving objects using their cameras. A ranger communicates with each of the scouts and determines whether there are objects of potential interest within the observed area. The paper also includes experimental results for individual scout and ranger- scout activities. Key Words. Distributed robotics, miniature robots, robotic teams. Key Words. Distributed robotics, miniature robots, robotic teams. wb1-3 Trajectory Planning and Control for Mobile Manipulator Systems Authors: Papadopoulos E., National Technical University of Athens, Greece Poulakakis J., National Technical University of Athens, Greece ABSTRACT Mobile manipulator systems, comprised of a mobile platform with one or more manipulators, are of great interest in a number of applications. This paper presents a methodology for computing actuator commands for such systems that allow them to follow desired end-effector and platform trajectories without violating the nonholonomic constraints. Based on a reduction of the system dynamics, a model-based controller is designed to eliminate tracking errors without requiring large gains. The validity of the methodology is demonstrated using differential- drive and car-like mobile manipulator systems. Key Words. Mobile manipulators, path planning, nonholonomic systems, crack sealing. wb1-4 WB2 Linear Systems II: Design Zero Structure Assignment of Matrix Pencils by Additive Structured Transformations Authors: Leventides J., University of Athens, Greece Karcanias N., City University, United Kingdom Kraounakis S., City University, United Kingdom ABSTRACT Matrix Pencil Models are natural descriptions of linear networks and systems. Changing the values of elements of networks, that is redesigning them implies changes in the zero structure of the associated pencil by structured additive transformations. The paper examines the problem of zero assignment of regular matrix pencils by a special type of structured additive transformations. For a certain family of network redesign problems the additive perturbations may be described as diagonal perturbations and such modifications are considered here. This problem has certain common features with the pole assignment of linear systems by structured static compensators and thus the new powerful methodology of global linearisation [1,2] can be used. For regular pencils with infinite zeros families of structured degenerate additive transformations are defined and parameterized and this lead to the derivation of conditions for zero structure assignment, as well as methodology for computing such solutions. Finally the case of regular pencils with no infinite zeros is considered and conditions of zero assignment are developed. The results here may provide the means for studying problems of linear network redesign by modification of the nondynamic elements. Key Words: Linear Systems, Systems Redesign, Matrix Pencils, Frequency Assignment, Algebrogeometric methods and Global Linearisation. wb2-1 Design of Low-Order Controllers for Linear Discrete- Time Systems with Nonrandom Disturbances Authors: Polyak B.T., Institute for Control Science, Russia Vishnyakov A.N., Institute for Control Science, Russia ABSTRACT We consider LTI SISO systems with nonrandom disturbances. The problem is to synthesize low- order controllers for optimal disturbance attenua- tion in such systems. The main idea is to fix a desired closed-loop characteristic polynomial, then a performance index is a convex function of controller coeficients. The case of l1 and l 1 -bounded disturbances is under consideration. New algorithms for solving the arising linear programming problems are proposed. The example demonstrates the advantages of the new techniques. wb2-2 Robust Triangular Decoupling via Measurement Output Feedback Authors: Koumboulis F., University of Thessaly, Greece Skarpetis M., University of Thessaly, Greece ABSTRACT The problem of robust triangular decoupling (RTD), via measurement output feedback (MOF), is solved. The general analytical expressions of the feedback matrices, are derived. The stability properties of the resulting RTD closed loop system are proven to be analogous to those in RTD via pure state feedback. All above results are successfully applied to control the steering dynamics of cars with four wheels steering (4WS) and with no measurement of the lateral acceleration . Key Words. Robust control, I/O Triangular Decoupling, Measurement Output Feedback, Linear Systems. wb2-3 Noninteracting Control for Submarine in Straight Horizontal Course Authors: Koumboulis F., University of Thessaly, Greece Skarpetis M., University of Thessaly, Greece Kouvakas N., University of Thessaly, Greece Vlachos N., University of Thessaly, Greece ABSTRACT It is proposed to perform accurate manoeuvring of a submarine in straight horizontal course, with independent control of elevation angle and heave velocity. Independent control is accomplished via a noninteracting control technique using a static state feedback law. The general analytic expression of the feedback controllers satisfying the I/O decoupling requirement is derived. The necessary and sufficient conditions for noninteracting control with simultaneous stability are explicitly determined in terms of the stability derivatives of the submarine. Key Words. Noninteracting control, Linear Systems, Submarine control, Stability wb2-4 Design of Control Systems by a Method of Structural Functions Authors: Groumpos P. - University of Patras, Greece Kusimov S., Ufa State Aviation Technical University, Russia Ilyasov B., Ufa State Aviation Technical University, Russia Vasilyev V., Ufa State Aviation Technical University, Russia Munasypov R., Ufa State Aviation Technical University, Russia ABSTRACT An approach to purpose-oriented design of the complex dynamic systems based on presentation of the system as a structural oriented graph is considered. The arcs of this graph are described by a pair of structural functions, which reflect an internal structure of a system based on its decomposition with use of amplifiers and integrators. The method of design is based on the use of structural criteria formulated in the form of structural functions. Key Words. Structural design, modal control, control systems, oriented graph, structural functions wb2-5 WB3 Factory Automation A decision support model for technical data aggregation and flow assessment in production networks Authors: Baillet-Farthouat P., LAP/GRAI University of Bordeaux, France Pereyrol F., LAP/GRAI University of Bordeaux, France Bourrieres J.-P., LAP/GRAI University of Bordeaux, France ABSTRACT A multi-level technical data model and a method to assess the throughput of aggregated production units is presented. A generic template guides the application of recursive aggregation operators which are assumed to be defined by a human expert. This approach aims to support the macro-evaluation of performances to be expected from networked complex manufacturing units. Key words :Global Manufacturing, Data Aggregation, Production Networks, Flow Assessment wb3-1 Lot Streaming Single Product in Three Machine Flowshops Authors: Wagneur E., Ecole des Mines de Nantes/IRCCYN, France ABSTRACT We consider the problem of mini- mizing makespan in a no-wait flowshop with three machines. A lot consists of many identical items of the same product. Lot streaming (lot sizing) is the process of creating sublets to move the completed portion of a production sublet to downstream ma- chines so that operations will be overlapped, for each product, we first consider the number of sublots as given, and we obtain optimal continuous-sized sublots. Some general results are proved for the gen- eral no-wait flow-shop with an arbitrary number of machines. These results are then applied to the 3- machine case, to find the optimal size sublots. Then, using this solution, and assuming there is a setup time between the transfer of batches, the optimal number of sublots is derived for the '2-machine no- wait flow-shop. For the 3-machine cases, we distin- guish two situations. A closed form formula is proved in the first, and a lower bound is provided in the sec- ond. Key words and phrases: No-wait flowshop, lot streaming, batches. wb3-2 A Low Cost Digital Current Transducer Authors: Pross A. - Coventry University, United Kingdom ABSTRACT This paper describes a Non-Hall effect current transducer, which provides galvanic isolation between the input and output whilst transmitting both ac an dc signals. The current transducer is used in electronic drives and controls systems where the special features of digital output and lack of Hall effect devices coupled with symmetrical magnetic structure is of benefit. The new design uses a ferrite core without an air gap, proving a limit cycle for the transmission of input signals. The limit cycle supports the production of a digital output signal. Key Words: Transducers, Limit Cycle, Current Transducer, Digital Current Transducer wb3-3 Laser Computer-Aided Systems for GTE Gas-Air Track Elements Inspection Authors: Galiulin M. Rav., Ufa State Aviation Technical University, Russia Galiulin M. Rish., Ufa State Aviation Technical University, Russia Bakirov M.J., Ufa State Aviation Technical University, Russia Bogdanov R.D., Ufa State Aviation Technical University, Russia Vorontsov V.A., Ufa State Aviation Technical University, Russia Ponomarenk V.I, Ufa State Aviation Technical University, Russia Tumashinov B.A., Ufa State Aviation Technical University, Russia Petrov V.S., Ufa State Aviation Technical University, Russia Yudin A.A., Ufa State Aviation Technical University, Russia ABSTRACT The technical characteristics, advantages and applications of an automated optoelectronic measuring system for inspection of gas-turbine engine (GTE) element parameters designed by "Optel" company, State Aviation University of Ufa are presented in this paper. The measuring apparatus can be applied for research in industry. Its main advantages are non-contact and high scanning speed. Key words. GTE, inspection, optoelectronic, measurements, software. wb3-4 Optimization of Microsensors Structures through Hall- Effect Modelling Authors: Caruntu G., Merchant Marine Institute, Romania Beizadea H., Maritime Training Centre, Romania Popa D., Maritime Training Centre, Romania ABSTRACT In this paperwork, based on the model of dual Hall devices, it is analysed the operation, and are established the main characteristics for two magnetotransistors structures, realised in the MOS and the bipolar integrated circuits technology. Using numerical simulation it is emphasized the way in which the choise of its geometry and material features, allow the obtaining of high performance magnetic sensors. There are also presented and described the original electrical diagrams of the transducers which contain such sensors, proposing possible applications in naval installation. Key Words: double-collector magnetotransistors, offset equivalent magnetic induction, noise equivalent magnetic induction, signal-to noise ratio, detection limit. wb3-5 WB4 Intelligent Control: Theory Validation of Adaptive-Critic Based Infinite Time Optimal Neuro Control for Distributed Parameter Systems Authors: Padhi R., University of Missouri-Rolla, USA Balakrishnan N.S., University of Missouri-Rolla, USA Randolph T., University of Missouri-Rolla, USA ABSTRACT Recently the necessary conditions of optimality for distributed parameter systems described in discrete domain have been developed, followed by the synthesis of the infinite time optimal neuro-controllers in the framework of adaptive-critic design. In this paper, we validate this synthesis methodology by comparing it with two other different approaches already established in the literature. Key Words. Distributed parameter systems, infinite dimensional systems, partial differential equations, optimal control, dynamic programming, neural networks, adaptive-critic synthesis. wb4-1 Optimization of a fuzzy logic controller using genetic algorithms Authors: Kanarachos A., National Technical University of Athens, Greece Koulocheris D., National Technical University of Athens, Greece Vrazopoulos H., National Technical University of Athens, Greece ABSTRACT The scope of this paper is to present an optimised fuzzy logic controller used in suspension system for ground vehicles. The vehicle system is described by linear differential equations subject to many types of road irregularities. The fuzzy logic rules are optimised such that the maximum value of vertical and rotary acceleration of vehicle body at the passengers seats are minimised from the view point of ride comfort under the geometrical constraints of the car. The simulation results show that the proposed fuzzy logic controller improved the vehicle ride comfort. Key Words. Fuzzy logic controller, optimisation, genetic algorithms, semi-active suspension systems wb4-2 Adaptive Mode Transition Control of Nonlinear Systems using Fuzzy Neural Networks Authors: Rufus F., Georgia Institute of Technology, USA Vachtsevanos G., Georgia Institute of Technology, USA Heck B., Georgia Institute of Technology, USA ABSTRACT An adaptation scheme is proposed for the online customization of mode transition controllers designed off-line via the method of blending local mode controllers. It consists of the desired transition trajectory model, the active plant model and the active controller model, which is the mode transition controller. The latter two models are initially off-line trained and online adapted via structure/parameter learning. The control sensitivity matrix and the one-step-ahead predictive output of the active plant model are used to adapt the parameters of the mode transition controller such that the desired transition trajectory is tracked. The proposed adaptation scheme is illustrated for a hover to forward flight mode transition control of a helicopter encountering parametric changes and wind disturbances. Key Words. Adaptive tracking control, fuzzy neural networks, mode transition control, kaczmarz's algorithm. wb4-3 Stability Analysis of Takagi-Sugeno Fuzzy Systems with Linear Input-Output Submodels Authors: Dvorakova R., Czech Technical University, Czech Republic Husek P. - Czech Technical University, Czech Republic ABSTRACT This paper presents a method analyzing stability of Takagi-Sugeno fuzzy systems with linear input-output submodels in the consequents of rules. This method can be used for stability analysis of a Takagi-Sugeno fuzzy model of a plant and for closed-loop system, where both the plant and the controller are represented by Takagi-Sugeno fuzzy systems. It will be shown that the problem of stability analysis of such a system can be transformed to robust stability analysis of a polynomial with polynomic structure of its coefficients. Stability of such polynomials is tested by the Modified Jury criterion, the Modified Routh criterion or the Hurwitz criterion together with Sign-decomposition. A necessary condition for stability of the Takagi-Sugeno closed loop systems is obtained. Keywords. Takagi-Sugeno fuzzy systems, stability analysis, polynomials, polynomic uncertainty wb4-4 Improved Training of Multilayer Feedforward Neural Networks for Large Input Vectors Authors: Caleanu C.-D. - University Politehnica Timisoara, Romania L. Petropoulakis, University of Strathclyde, Scotland ABSTRACT In this paper, a new fuzzy controller for inferring multiplayer feedforward neural networks learning rate is presented. The key issue is using relative values of a performance attribute as fuzzy controller inputs, resulting in an increased generality of fuzzy learning rate adaptation and a faster training algorithm. Experimental results demonstrate improvements in terms of generalization capability and of learning speed in both large pattern recognition and data processing tasks. Key Words. Neural nets, fuzzy control, training, algorithm. wb4-5 WC1 Control Applications Local and Global Bifurcations in a Power system with two cascaded regulators. Authors: Manos G., National Technical University of Athens, Greece Makridou K., National Technical University of Athens, Greece Vournas C., National Technical University of Athens, Greece ABSTRACT This paper investigates local and global bifurcation phenomena in a power system with two cascaded Load Tap Changer transformers. These devices regulate voltage at two different voltage levels. Conditions for oscillatory behavior and the stability of the system are extracted. The interaction between the two devices is also considered. More specifically, it is shown how the cascaded time constants influence the monotonic or oscillatory behavior of the system and the formation of a homoclinic loop bifurcation. Key Words. Power system control, cascaded regulators, bifurcations, limit cycle, homoclinic loop. wc1-1 Global Asymptotic Stabilization of Chen's Chaotic System via Inverse Optimal Control Authors: Sanchez N.E., CINVESTAV, Unidad Guadalajara, Mexico Perez P.J., CINVESTAV, Unidad Guadalajara, Mexico Martinez M., Universidad Autonoma de Nuevo Leon, Mexico Chen G., University of Houston, USA ABSTRACT In this paper, a novel approach is developed for global asymptotic stablization of Ghen's chaotic system, which in priciple works for other complex nonlinear systems as well. Based on a recently introduced methodology of inverse optimal control for nonlinear systems, a very simple stabilization control law is derived for the desired global asymptotic stabilization. Computer simulation is given for illustration and verification. Keywords: Chaos, Nonlinear Systems, Inverse Optimal Control, Stability. wc1-2 Band-saw feed speed / cutting speed ratio measuring and control Authors: Boyanov S. - University of Forestry-Sofia, Bulgaria Penev D., Technical University of Sofia, Bulgaria ABSTRACT This paper formulates the problem of determining the cutting mode and the control mode of the band saw. The focus of this paper is the measurement of the cutting speed. It describes the structure and the operation of a device developed by the authors for direct, contact less measurement of the band-saw speed, the feed speed of the material, for estimation of the ratio of these speeds, recording and primary processing of the measurement results. A mathematical model has been created and the possibility to make a system of ratio speed control based on the measurements done by the device. Keywords: Band saw, digital data processing, measurement of speed, ratio speed control wc1-3 Stabilization of Program Motion of Nonlinear Object with Incomplete Information about the State Vector Authors: Pyatnitskiy E.S. - Institute of Control Sciences, Russia ABSTRACT The method of nonlocal stabilization of the program motion is developed under condition of incomplete information about vectors of state when some coordinates are unobservable. wc1-4 Path generation in joint coordinates for a prescribed motion of the end-effector of a robot Authors: Chircor M., "Ovidius" University Constanta, Romania Zagan R., "Ovidius" University Constanta, Romania ABSTRACT In this paper there is presented a method for the determination of the time histories of the internal co-ordinates of a serial type robot when the end-effector is moving along a spatial trajectory. This allow us to command the trajectory of the end-effector practically along any trajectory in the three-dimensional space. The method presented is simple and can be used for any type of robot. There is also demonstrated the existence of the solutions for the problem mentioned above. Key words. Industrial robot , Internal coordinates , Generation of trajectories , Control of the motion. wc1-5 Discrete-Time Linear-Quadratic Output Versus State Regulator Authors: Gessing R., Politechnika Slaska, Poland ABSTRACT An augmented and minimal realization state space models are proposed for direct implementation of the discrete-time linear-quadratic regulator (DLQR) with measured not all the state variables but only the output of the plant. Both the models are related by means of original transformation with a rectangular matrix. Using this transformation it is shown that the resulting closet-loop (CL) system with dynamic output feedback regulator (DOFR) has the same stable roots of its characteristic equation as the CL system with state feedback and DLQR; the additional zero roots of the rst CL system generated by DOFR do not change its properties, essentially. Itisalsoshown that the CL system with DOFR realizes the optimal control with feedback from an augmented state, resulting from solving an appropriate DLQR problem. Key Words. Linear-quadratic regulator; discrete-time systems; state space models; ob- servers. wc1-6 WC2 Communications Active Performance Monitoring for Multimedia ATM Networks Authors: Burell A., Oklahoma State University, USA Papantoni T., University of Alabama, USA ABSTRACT We consider multimedia ATM networks with time-varying traffics and ologies. To deal effectively with the time-varying environment, the deployment of traffic and network performance monitoring techniques is necessary for the identification of traffic changes, network failures, and also for the facilitation of protocol adaptations and topological modifications. The objective of the paper is the design, analysis and evaluation of mobile intelligent agents that implement effective performance monitoring techniques, while capturing the dynamics inherent in the multimedia environments. Towards this objective, a core sequential algorithm which depicts the functionality and operations of the network performance monitoring techniques is adopted. Specific forms of the algorithm are used for the identification of networks failures. For a given network topology, the location of the minimum necessary set of agents for complete network and traffic "visibility" is be specified via identifiability methods. Key Words. Mulitmedia ATM Networks, Algorithmic Monitoring, Failure Recognition, Identifiability. wc2-1 Decision Feedback Differentially Detected GMSK Signals in the Presence of ACI and Nonlinearities Authors: Mathiopoulos T., Athens Observatory, Greece Toor S. J., Wireless Locat Technologies Group, Seattle, USA ABSTRACT The effects on the performance of difFerentially detected Gaussian Minimum Shift Keying (GMSK) signals operated in the presence of adjacent channel interference (ACl), modulator impairments, amplifier nonlinearities and additive white Gaussian noise (AWGN) is investigated. By means of computer simulation, the bit error rate (BER) performance of 1and 2-bit conventional and decision feedback differentially detected (C-DD and DF-DD) GMSK systems in the presence of static and Rayleigh faded ACl is obtained. It is found that the best performance is achieved by the 2-bit DF-DD receiver and has resulted in BER performance improvements for the static ACl channel and error floor reductions for the Rayleigh faded ACl channel. wc2-2 Loss Volume in Continuous Flow Models: Fast Simulation and Sensitivity Analysis via IPA Authors: Wardi Y., Georgia Institute of Technology, USA Melamed B., Rutgers University, USA ABSTRACT This paper defines a class of uid- ow models, called Continuous Flow Models (CFMs), representable as DEDS (Discrete Event Dynamic System) models. The CFM class is motivated by emerging high-speed packet-based telecommunications networks for which traditional queueing simulations at the packet level are prohibitively costly in time and space, or simply infeasible. In contrast, CFM-based uid- ow networks hold the promise of fast simulation for applications ranging from network design to network control. The paper studies the loss volume metric of a basic CFM in some detail. This metric is easily converted to loss probabilities { an important ingredient in quality of service (QoS) metrics for modern telecommunications networks. The paper further performs sensitivity analysis of CFMs via IPA derivatives of the loss volume as function of buffer size, as well as service rate and arrival rate parameters. Simple formulas for these derivatives are derived and shown to be amenable to real-time computation. The formulas have a broad applicability dueto their nonparametric (distribution-free) nature, a fact that makes them potentially suitable for real-time control applications in telecommunications networks. Key words. CFM, Continuous Flow Models, High-Speed Networks, IPA, Loss Metrics. topics addressed. Discrete event systems. wc2-3 TOP A Cybernetic Model of Computerisation of the Cultural Heritage Authors: F. Filip, Nat. Institute for R&D in Informatics, Romania D. Donciulescu, Nat. Institute for R&D in Informatics, Romania C. Filip, Nat. Institute for R&D in Informatics, Romania ABSTRACT An e-Europe for all should include the facilitation of European citizens to the cultural heritage of Europe and Mediterranean area. This paper proposes a vision for a transition to complex systems combining IT organisations and cultural institutions. It describes the impact and limits and proposes a preliminary cybernetic model to study the relationship between the organisations implied. Keywords: business processes, computer networks, cultural heritage, discrete time systems, information technology, library, museum, social impact, simulation. wc2-4 Energy Considerations in Mobile ad-hoc Networks Authors: Tragoudas S., Southern Illinois University, USA ABSTRACT The nodes of a mobile ad hoc network run on local energy sources. This paper identifies energy related problems in network management and routing which when appropriately tackled increase the reliability of the network. A new routing method for improved quality of service is presented that takes into consideration the energy life of each node. We also present a methodology for recharging the energy sources of the mobile nodes with minimal impact on the network's reliability. Key Words. Wireless communication, mobile networks, network reliability, routing protocols wc2-5 WC3 Intelligent Control: Applications Design of Incremental Fuzzy Supervisory Controllers for the Optimization of the Injection Molding Process Authors: Tzafestas G.S., National Technical University of Athens, Greece Vagelatos A.G., National Technical University of Athens, Greece Rigatos G.G., National Technical University of Athens, Greece ABSTRACT In this paper a newly developed fuzzy supervisory control system for the injection molding process is presented. The system performs automatic tuning of the machine operating points and reduces the human effort for a complete optimization of the machine settings. The experimental results obtained from the application of the proposed fuzzy control architecture in a real industrial environment were encouraging Keywords. Injection Molding Process, incremental fuzzy supervisory control, self-tuning systems, knowledge-based systems wc3-1 Optimal Chemotherapy Regiments: Influence of Tumor on Normal Cells and Several Toxicity Constraints Authors: Matveev A., The University of Western Australia, Australia Savkin A., The University of Western Australia, Australia ABSTRACT Cancer chemotherapy with application of one drug is studied. The negative and inhibiting effect of the tumor on normal cells is taken into account. Under certain hypotheses, we determine the optimal regimen that minimizes the tumor burden at the end of a fixed period of therapy while maintaining certain normal cell populations above prescribed levels. More precisely, it is demonstrated that the optimal strategy corresponds to injection of the drug at the maximal rate. Keywords. Optimal chemotherapy regimen, in uence of tumors on normal cells wc3-2 Estimation of Electric Fields to High Voltage Substations Design Using Artificial Neural Networks Authors: de Souza A., State University of Sao Paulo - UNESP, Brazil da Silva I., State University of Sao Paulo - UNESP, Brazil Bordon M., State University of Sao Paulo - UNESP, Brazil ABSTRACT This paper describes a novel approach to map electric fields using artificial neural networks. The networks acts as an identifier of structural features of the high voltage substations design so that output parameters can be estimated and generalised from an input parameter set. Simulation examples are presented to validate the proposed approach. More specifically, the neural networks are used to compute electrical fields intensity and critical voltage taking into account several atmospheric and structural factors, such as pressure, temperature, humidity, distance between phases, height of the bus bars, and wave forms. A comparative analysis with the finite element method is also provided to illustrate this new methodology. Key Words. Artificial neural networks, High voltage, Electric fields, Substations, Atmospheric impulses. wc3-3 Long Range Forecasting of Hourly Power System Load by Artificial Neural Network via Ordered Walsh Transform Authors: Bhirud S.G., Shri Guru Gobind Singhji, India Basu T.K., Indian Institute of Technology, India ABSTRACT | Long range forecasts of hourly loads spanning 52 weeks (1 year) not only facilitates preparation of capital repair schedules of generating units for preventive maintenance in an integrated system, but may also obviate the need for medium range forecasts in certain situations. The varying nature of power system data having multiple periodicity of 24 hours/168 hours (1 day) /(1 week) makes it suitable for the application of Digital Image Processing technique. An attempt has been made to represent the data in the form of an image replacing the time variables by space variables. Thus the inter pixel gap of the image represents the sampling time of 1 hour along the horizontal axis and 24 hours along the vertical axis. Transforming the image by 2-D Ordered Walsh Transform (OWT) and modeling the OWTs of successive years via an Articial Neural Network (ANN), forecasts are made by taking inverse of the forecast OWTs from the ANN. The dynamics of the process is captured by an input output relation for the ANN model, the parameters of which can be obtained by training the ANN with a given large set of sample input/output data (OWTs). Keywords: Long Range Forecast, Articial Neural Network, Ordered Walsh Transform wc3-4 Algorithms for Computing Fuzzy Model Network Systems Authors: G. Vachkov, Nagoya University, Japan T. Fukuda, Nagoya University, Japan ABSTRACT In this paper several algorithms for computing the specially proposed Fuzzy Model Network Systems (FMNS) are presented and analyzed. FMNS are complex structures consisting of a number of interrelated simple fuzzy model units and linear junction units (modules). The main computation problem in FMNS is to calculate a part or the entire set of the unmeasured variables in the system with a predetermined structure and known set of measured variables. The computational algorithms presented in this paper include: 1) non-iterative computation of a feedforward type of FMNS; 2) iterative inverse calculation of one-dimensional fuzzy model units and 3) iterative calculation of closed loop (cyclic type) FMNS by use of a specially proposed fuzzy iteration block. All the proposed algorithms are explained and illustrated on numerical examples with comments about their practical application to industrial systems and plants. Key Words. Network structures, fuzzy models, inverse fuzzy models, iterative algorithms wc3-5 Modeling and Data Reconciliation of the Heat Retaining Panel System of Hot Strip Mill Authors: M. Petkova, Univ. of Chemical Technology and Metallurgy, Bulgaria N. Christova, University of Patras, Greece ABSTRACT The aim of this work is the modeling of the process of cooling of a metal plate in the presence of thermal reflecting panels on the intermediate table of a hot strip mill. A mathematical model of the process of cooling has been developed in order to study the temperature behavior in the metal under different initial and boundary conditions. The problem of reconstruction of temperature field in a metal plate is investigated, as well as methods for its decision. Also the problems of data reconciliation and fault measurement diagnosis are discussed in this paper. The soft computing method is implemented in a combination with the mathematical model of the cooling process of the metal. The obtained results show that this method is a suitable and powerful tool, capable to eliminate the initial uncertainties in temperature measurement and to estimate the temperature profile inside the strip. Key words. Modeling, heat retaining panel system, data reconciliation, soft computing method wc3-6