Giuseppe Boccolato*, Ionut Dinulescu **, Alice Predescu***, Dorian Cojocaru****
University of Craiova, *gboccolato@gmail.com, **ionutdinulescu@gmail.com, ***predescualice@gmail.com, ****cojocaru@robotics.ucv.ro

Abstract: This paper deals with the subject of a hyper-redundant robot control simulation. This type of arm changes its configuration by bending a continuous backbone formed of sections connected in a serial configuration. Theoretically the arm can achieve any position and orientation in the working space. A tentacle arm prototype was designed and the practical realization is now running in open loop. The goal of this paper it’s to establish the constructive way to build the visual algorithm to control the system. One limitation introduced about the visual serving system is that it does not answer in real time. The delay introduced by the image-processing task is taken into consideration and simulations are performed to design Closed-Loop control that stabilizes the system.
Keywords: hyper-redundant, arm, simulation, control, robot.

Daniela Danciu*
*Department of Automatic Control, University of Craiova, A.I.Cuza, 13, Craiova, RO-200585, Romania (e-mail: daniela@automation.ucv.ro)

Abstract:This paper deals with the analysis of the absolute stability for a class of scalar nonlinear timedelay systems having monotone increasing nonlinearities. The approach is based on frequency domain inequalities of Popov type for time-delay systems in the critical case of the transfer function with a simple zero pole. In order to solve the minmax problem which arises from the frequency domain inequality, the analytical analysis was completed by numerical computations using MATLAB software package. We have obtained a time-delay dependent absolute stability condition.
Keywords: Absolute stability, Frequency domain inequality, Limit stability, Time-delay system.

Radu Dobrescu*, Eugen Iancu**, Emil Petre**, Eugen Bobasu**
*University “Politehnica” of Bucarest, 313 Splaiul Independentei Street, RO-060042, Bucharest, Romania (E-mail: radud@isis.pub.ro, http://www.upb.ro) **Department of Automation, University of Craiova, 107 Decebal Street, RO-200440 Craiova, Romania (E-mail: {Eugen.Iancu, epetre, ebobasu}@automation.ucv.ro, http://www.ace.ucv.ro)

Abstract: The system sensitivity analysis (SSA) is a mathematical method used in the behavior dynamic systems study. Simulation estimates time evolution and quantitative changes for the system variables in the case of changes in internal structure. The study of SSA for populations cells control, proves that SSA can be apply also to biological systems, it offers useful data for the medical practice and it contributes to introduce the computer assisted diagnosis in current medical assistance.
Keywords: Bioengineering, Modeling and simulation, Predictive control, System sensitivity analysis.

Bogdan Dumitrascu*, Adrian Filipescu*
* Department of Automation and Electrical Engineering University “Dunarea de Jos” of Galati, Galati, Romania (e-mail: dumi_b20@yahoo.com, Adrian.Filipescu@ugal.ro)

Abstract: The sliding-mode controller (SMC) for the lateral motion control problem of Four Driving-Steering Wheels (4DW/SW) vehicle is presented in this paper. The lane centerline tracking is the main control performance. The dynamic model of the vehicle has been taken into account. Closed-loop robustness to uncertainties is achieved. The lane centerline tracking is achieved using look-ahead techniques. Closed-loop simulation and real time results with 4DW/SW SEEKUR robot base show the efficiency of sliding-mode control. Compared to 2DW and one or two SW mobile robots control, the 4DW/SW sliding-mode control is more stable with smaller lateral error.
Keywords: Sliding Mode Control, Autonomous Vehicle, Computer Control, Four Wheel Drive/Steering.

Alina Patelli*, Lavinia Ferariu*
*”Gh. Asachi” Technical University of Iasi, Department of Automatic Control and Applied Informatics 700050 RO (e-mail: apatelli@tuiasi.ro, lferaru@tuiasi.ro)

Abstract: The paper suggests a customized evolutionary identification tool for the automatic generation of complex nonlinear systems’ models. The proposed algorithm features a novel regressor encapsulation mechanism, based on fuzzy logic, aimed at guiding crossover cut point selection. To encourage the production of well adapted offspring, a fuzzy controller identifies the model terms which would bring the most relevant gain in fitness, if swapped via crossover. The authors contrast two methods of tuning the fuzzy membership functions’ parameters, both in a static and a dynamic way, in order to accurately capture regressor relevance. In addition, the basic multiobjective evolutionary loop is upgraded with original similarity analysis and genetic material refreshment mechanisms aimed at preserving population diversity. The practical usefulness of the proposed tool is demonstrated within an experimental trial involving the identification of a complex nonlinear industrial system within the Sugar Factory of Lublin, Poland.
Keywords: evolutionary algorithms, nonlinear systems identification, multiobjective optimization, fuzzy logic.

Ionela Prodan*, Sorin Olaru*, Cristina Stoica*, Silviu-Iulian Niculescu**
*SUPELEC Systems Sciences (E3S) - Automatic Control Department, 3 rue Joliot Curie, F-91190, Gif-sur-Yvette cedex, France (e-mail: {Ionela.Prodan, Sorin.Olaru, Cristina.Stoica}@supelec.fr). **Laboratory of Signals and Systems, SUPELEC - CNRS, 3 rue Joliot Curie, Gif-sur-Yvette, France (e-mail: {Ionela.Prodan, Silviu.Niculescu}@lss.supelec.fr)

Abstract: This paper deals with avoidance constraints while following an optimal trajectory fora group of agents operating in open space. The basic idea is to use the Model Predictive Control(MPC) technique to solve a real time optimization problem over a finite time horizon. Following a specified trajectory, the agents move in the same direction and eventually they end up in a particular formation. Combining the optimization-based control study with the ability of MPC to handle convex and non-convex constraints allows a thorough analysis of the motion control of a group of agents with linear dynamics subject to state constraints. Avoidance constraints are also added to the optimization problem when the agents are operating in an environment with obstacles. A at trajectory is planned in the physical open space allowing the agents to maneuver successfully in such a dynamic environment and to reach a common objective.
Keywords: Multi-agent systems, cooperative control, Model Predictive Control, non-convex constrains.

Vladimir Rasvan*, Dan Popescu*, Daniela Danciu*
*Department of Automatic Control, University of Craiova, Craiova, Romania (e-mail: {vrasvan, dpopescu, daniela}@automation.ucv.ro)

Abstract: In this paper there is presented a rather straightforward application of the absolute stability frequency domain inequalities to the practical problem of PIO (Pilot In-the-loop Oscillations) proneness of aircrafts. An extended to critical cases version of the Yakubovich criterion for the case of slope restricted nonlinearities is applied to the benchmark case of the X15 landing flare incident.
Keywords: Absolute stability, Frequency domain inequalities, Self sustained oscillations, Yakubovich criterion.

Pedro Rodriguez-Ayerbe*, Sorin Olaru*
* Automatic Control Department of SUPELEC (E3S), 91192 Gif-sur-Yvette, France (Tel: +33-143267485; e-mail: pedro.rodriguez@supelec.fr, sorin.olaru@supelec.fr)

Abstract: The paper deals with the predictive control for linear systems, described by piecewise affine (PWA) control laws formulations. The main goal is to reduce the sensitivity of these schemes with respect to the model uncertainties. This objective can be attained by considering worst-case (min-max) formulations, optimization over the control policies or tube predictive control. These comprehensive approaches may lead to fastidious on-line optimization thus reducing the range of application. In the present paper, a two stage predictive strategy is proposed, which synthesizes in the first place an analytical (continuous and piecewise linear) control law based on the nominal model and secondly robustifies the control law in the neighborhood of the equilibrium point using the Youla-Kucera parameter (the feedback gain obtained for the unconstrained control problem - most often assimilated to the LQR gain). This robustification is globally expanded to all the state space of the piecewise structure by means of its corresponding disturbance model.
Keywords:

Mihnea Scafes*, Costin Badica**
*University of Craiova, Software Engineering Department, Bvd.Decebal 107, Craiova, 200440, Romania (e-mail: scafes mihnea@software.ucv.ro) **University of Craiova, Software Engineering Department, Bvd.Decebal 107, Craiova, 200440, Romania (e-mail: costin.badica@software.ucv.ro)

Abstract: This paper presents an overview of existing models of automated negotiation in multi-agent systems with a special focus on complex negotiations involving non-linear utility functions.
Keywords: Automated negotiation, Multi-agent Systems.

Mohamed A. Sehili*, Dan Istrate*, Jérôme Boudy**
*LRIT-ESIGETEL, 1 Rue du Port de Valvins,77210 Avon, France, (e-mail:{mohamed.sehili, dan.istrate}@esigetel.fr), ** Telecom SudParis, 9 Rue Charles Fourier, 91000 Evry, France (e-mail: {jerome.boudy, mohamed.sehili}@it-sudparis.eu)

Abstract: The advent of modern communications and the low cost of some kinds of devices have resulted in a desire to equip elderly peoples' homes with sensors to monitor their activities and be forewarned of abnormal situations. In such an environment, sound may represent a rich source of information that can be exploited and this is considered as one of the most ergonomic and least intrusive solutions. However, this solution is often adversely affected by noise that is to say, mostly sounds of a type not taken into account in the creation of this system. Several methods were used to make it possible to classify sounds. In this work we tested Support Vector Machines to classify sounds in a domotic environment.
Keywords: Domotic system, sound classification, pattern recognition, support vector machines.

Dorin Sendrescu*
*University of Craiova, Department of Automatic Control, 200585-Craiova, Romania (Tel: +40-251-438198; e-mail: dorins@automation.ucv.ro)

Abstract: Most systems that are encountered in practice are subjected to various uncertainties such as nonlinearities, actuator faults parameter changes etc. Modeling and identification of electro-mechanical systems constitute an essential stage in practical control design and applications. For a electro-mechanical rotational system, the nonlinearities, like Coulomb friction and dead zone, significantly influence the system operation when the rotation changes direction. The paper presents the black-box nonlinear identification of a rotational flexible joint setup. The nonlinear model for the system is obtained based on the discrete second order nonlinear Volterra model. Off-line identification of the nonlinear system model is performed using the least mean square algorithm. Results of the real time experiments are graphically and numerically presented, and the advantages of the nonlinear identification approach are revealed.
Keywords: Adaptive identification, Volterra model, Nonlinear systems, Flexible joint.

Roxana Stanica*, Emil Petre**
*University of Craiova, Romania (e-mail: roxana_batm@yahoo.com) **University of Craiova, Romania (e-mail: epetre@automation.ucv.ro)

Abstract: Quality of Service (QoS) controls the traffic congestion by assigning priorities to the transmitted packets. QoS queuing policies can protect bandwidth for important categories of applications, or specifically limit the bandwidth associated with less critical traffic. In this paper, four new Hybrid scheduling commands are proposed. The new commands combine Strict Priority (SP) and Weighted Round Robin (WRR) scheduling. The transmission of packets is done using eight queues, and each queue can be controlled by one of the Hybrid commands.
Keywords: priority, data packet, hybrid scheduling, command.