Ste

ANNALS OF THE UNIVERSITY OF CRAIOVA

Series: AUTOMATION, COMPUTERS, ELECTRONICS and MECHATRONICS


    ISSN: 1841-0626 CNCSIS code 11 category B+ internationally indexed, starting with 2010, (Copernicus, Inspec)
    Semiannual publication
    Occasionally, conferences dedicated special issues may be published

    Year 2010 Volume 7(34) no. 1
  1. DESIGNING A QUEUE EVENTS SYSTEM FOR ROAD TRAFFIC SIMULATOR (pp. 1-6)

    Camelia Avram*, Adina Morariu*, Honoriu Valean*, Adina Astilean*
    *Technical University of Cluj Napoca, Romania
    (e-mail:{camelia.avram, adina.pop, honoriu.valean, adina.astilean}@aut.utcluj.ro


    Abstract: The urban traffic is frequently perturbed by congestions, followed by usual delays, accidents and road closures that cause supplementary delays. It is important to use intelligent systems for traffic simulation, routing strategies and scheduling techniques in order to achieve an optimal usage of resources. Scheduling message queues has strong similarities with algorithms used for giving different service rates to flows within network routers. In this paper a message scheduler that uses time based credit scheduling is proposed, in which resources are partitioned among messages solvers by allocating credits. Various aspects of the overall system are investigated in particular in relation to throughput, delay, scalability with processors and performance isolation.
    Keywords: computer simulation, concurrent programming, distributed control, communication protocols, computer communication networks

  2. A BRIEF STUDY OF REDUCING FUEL CONSUMPTION IN HYBRID ELECTRIC VEHICLES (pp. 7-14)

    Babici Cezar*, Alexandru Onea**
    * Automatic Control and Applied Informatics Department, "Gheorghe Asachi" Technical University of Iasi, Faculty of Automatic Control and Computer Engineering, Iasi, Romania (e-mail: cbabici@ac.tuiasi.ro)
    ** Automatic Control and Applied Informatics Department, "Gheorghe Asachi" Technical University of Iasi, Faculty of Automatic Control and Computer Engineering, Iasi, Romania (e-mail aonea@ac.tuiasi.ro)


    Abstract:Automotive control has become a driving factor in automotive innovation over the last twenty five years. In order to meet the enhanced requirements for lower fuel consumption, lower exhaust emissions, improved safety as well as comfort and convenience functions, automotive control had to be applied. The Interest in hybrid electric vehicles derives from several technical and economical considerations. Control strategies for hybrid topologies are algorithms for selecting the power split between the engine and the motor in order to minimize the fuel consumption and the emissions. For hybrid vehicles it is possible to use different kinds of batteries characterized by capacity and weight increasing the autonomy, in terms of working hours or distance. The principal aim of this paper is to demonstrate that fuel consumption and emissions can be reduced by using different control strategies in the same or different topologies..

  3. ROBUST CONTROL LAW DESIGN FOR A SYNCHRONOUS MOTOR USING FEEDBACK LINEARIZATION METHOD (pp. 15-20)

    Eugen Bobasu*, Dan Popescu**, Sergiu Ivanov***
    * Automatic Control Department, University of Craiova, Romania (e-mail: ebobasu@automation.ucv.ro)
    ** Automatic Control Department, University of Craiova, Romania (e-mail: dpopescu@automation.ucv.ro)
    *** Electrical Drives and Industrial Informatics Department, University of Craiova, Romania (e-mail: sivanov@em.ucv.ro)


    Abstract: In this paper a combination of the feedback linearizing control technique and Glover-McFarlane control method is applied for the control of a synchronous motor. The use of feedback linearization requires the complete knowledge of the nonlinear system. In practice, there are many processes whose dynamics is very complex, highly nonlinear and usually incompletely known. To improve robustness, it may be necessary to modify the exact linearization controller. First, we apply the method of nonlinear control and state feedback linearization to synchronous motor model and we obtain a nonlinear control law. This law, aggregated with our nonlinear system, achieves input-output linearization and in the case of multivariable approach, the nonlinear control law achieves also decoupling. Then, Glover-McFarlane H design is used with the goal of increasing robustness of the existing controller. Finally, some simulation results are included to demonstrate the performance of these controllers and the results are compared with the classical dq vector control.
    Keywords: synchronous machine, feedback linearization, robust control.

  4. A FAULT COVERAGE EVALUATION OF LINKED NEIGHBORHOOD PATTERN-SENSITIVE FAULTSIN RANDOM-ACCESS MEMORIES (pp. 21-26)

    Cristina Huzum*, Petru Cascaval*
    * Faculty of Automatic Control and Computer Engineering, “Gheorghe Asachi”, Technical University of Iasi, Romania (e-mail: cristinahuzum@yahoo.com, cascaval@cs.tuiasi.ro)


    Abstract: A fault coverage evaluation concerning a linked neighborhood pattern sensitive faults model (NPSFs) in N × 1 random-access memories is presented. For the simulation study, the most important published tests dedicated to the NPSF model have been considered. Simulation results show that these tests cover the entire model of simple NPSFs, but only the longer of them cover the linked NPSF model. In addition, a fault coverage evaluation of linked faults involving a single cell (LF1s), two cells (LF2s), and three cells (LF3s) is also presented
    Keywords: Memory Testing, Functional Fault Model, Static Faults, Linked Neighborhood Pattern-Sensitive Faults, March Tests.

  5. METHOD FOR DIAGNOSIS AND DECISION FOR PATIENTS WITH DIABETES MELLITUS (pp. 27-31)

    Eugen Iancu*, Emil Petre*, Ionela Iancu**
    *Department of Automation, University of Craiova, 107 Decebal Street, RO-200440 Craiova, Romania (e-mail: Eugen.Iancu@automation.ucv.ro, http://www.ace.ucv.ro)
    ** University of Medicine and Pharmacy of Craiova, 4, Petru Rares Street, RO-200349 Craiova, Romania (e-mail: iancu@yahoo.com, http://www.umfcv.ro)


    Abstract: In this moment we have many diabetes patients with poor control of blood glucose. Some authors consider that the closed-loop system (artificial pancreas) is the best solution. An extra-corporeal blood glucose sensor is coupled to a pump, which controls the rate of infusion of insulin so as to maintain normoglycaemia. The continuous glucose monitoring system uses other sensors for the measuring of the blood glucose, placed under or on the skin. One of the most dangerous situations, having severe consequences on a patient’s state is the introduction of incorrect values in the management system, responsible for all decisions and the control of the pump. For this reason it is necessary that each sample of blood glucose must be passed through a validation process. Therefore, it is very important that the transducers are in proper working condition. If one of the transducers provides inaccurate data, it must be quickly removed and replaced. The fault detection and isolation (FDI) problem is an inherently complex one. The author proposes an analytical method to detect and locate the presence of sensor failures using stochastic signal processing. The results of this study can also be applied to other physiological systems, offering important data for the medical practice and contributing to the introduction of computer assisted diagnosis, as a regular medical practice. These findings may have significant clinical implications in the diagnosis of diabetes mellitus, in blood glucose monitoring and in the management of diabetes therapy.
    Keywords: Continuous glucose monitoring, Blood glucose control, Fault detection and isolation.

  6. CONTROL OF THE MICROALGAE PHOTOSYNTHETIC GROWTH IN A TORUS PHOTOBIOREACTOR (pp. 32-38)

    George Ifrim*, Marian Barbu*, Mariana Titica**, Lionel Boillereaux**, Sergiu Caraman*
    *”Dunarea de Jos” University of Galati, 47 Domneasca, 800008, Galati, ROMÂNIA (email: George.Ifrim@ugal.ro)
    ** CNRS, GEPEA, UMR-CNRS 6144, University Bd., CRTT-BP 406, 44602 Saint-Nazaire Cedex, FRANCE, (email: Mariana.Titica@univ-nantes.fr)


    Abstract: The microalgae have the ability to use CO2 as carbon source and, together with the solar energy, to biosynthesize various components, generating O2. They have a huge potential in various industrial applications such as the production of therapeutic and industrial metabolites, biofuels and environmental applications. The aim of this paper is to control the photosynthetic growth of the microalga Chlamydomonas reinhardtii, in a continuous torus shape photobioreactor. The control strategy was to maintain the biomass concentration constant into the photobioreactor using the dilution rate as control variable. The main disturbance was the incident light flux. Two control laws were designed and analyzed in simulation, to wit a linear control algorithm and a nonlinear one. The linear controller was synthesized in a PI structure which was further tested in simulation at variable setpoints and incident light fluxes. The nonlinear controller was conceived in order to minimize the inconveniences encountered at the PI controller. The simulation conditions were identical for both controller types.
    Keywords: Chlamydomonas reinhardtii, photosynthetic growth control, linear controller, linearizant control, biomass growth process.

  7. H1N1 INFLUENZA ON ROMANIA TERRITORY (pp. 39-44)

    Adina Morariu*, Honoriu Valean**, Camelia Avram***
    * Technical University of Cluj Napoca, Romania (e-mail: {adina.pop, honoriu.valean, camelia.avram}@aut.utcluj.ro) @aut.utcluj.ro)


    Abstract: A pandemic is a worldwide epidemic of a disease. An influenza pandemic may occur when a new influenza virus appears against which the human population has no immunity. Epidemic propagation models have been applied on modeling the propagation of viruses. Some mathematical models and computer simulations deal with the spatial distribution of susceptible along a line, across a lattice or over a network to overcome the inaccuracies due to the assumption of random mixing of the population. The viral propagation is determined by intrinsic characteristics of the network. This work is focused on analyzing and fitting the classical SIR model to predict the course of pandemic H1N1 influenza on the Romania territory. An architectural system is proposed for implementing a web application for pandemic viruses that affected or can affect the Romania territory.
    Keywords: Models, Parameter estimation, Analysis, Systems, Architectures.

  8. IDENTIFYING FINGERPRINT ALTERATION USING THE RELIABILITY MAP OF THE ORIENTATION FIELD (pp. 45-52)

    Adina Petrovici, Corneliu Lazar
    Automatic Control and Applied Informatics Department, Technical University “Gheorghe Asachi”, Iasi, Romania (e-mail:{apetrovici; clazar}@ac.tuiasi.ro)


    Abstract: Fingerprint recognition is one of the most commonly used biometric technology. Even if fingerprint temporarily changes (cuts, bruises) it reappears after the finger heals. Criminals started to be aware of this and try to escape the identification systems applying methods from ingenious to very cruel. It is possible to remove, alter or even fake fingerprints (made of glue, latex, silicone), by burning the fingertip skin (fire, acid, other corrosive material), by using plastic surgery (changing the skin completely, causing change in pattern – portions of skin are removed from a finger and grafted back in different positions, like rotation or “Z” cuts, transplantations of an area from other parts of the body like other fingers, palms, toes, soles). This paper presents a new algorithm for altered fingerprints detection based on fingerprint orientation field reliability. The map of the orientation field reliability has peaks in the singular point locations. These peaks are used to analyze altered fingerprints because, due to alteration, more peaks as singular points appear with lower amplitudes.
    Keywords: Fingerprints, alteration, image enhancement, reliability, singular points.

  9. STABLE FUZZY CONTROL OF AN ELECTROMAGNETIC ACTUATED CLUTCH (pp. 53-60)

    Radu-Emil Precup*, Claudia-Adina Dragos**, Stefan Preitl***, Emil M. Petriu****, Mircea-Bogdan Radac***** and Adrian Sebastian Paul******
    * Department of Automation and Applied Informatics, “Politehnica” University of Timisoara, Bd. V. Parvan 2, Timisoara, Romania ( e-mail: radu.precup@aut.upt.ro)
    ** Department of Automation and Applied Informatics, “Politehnica” University of Timisoara, Bd. V. Parvan 2, Timisoara, Romania (e-mail: claudia.dragos@aut.upt.ro)
    *** Department of Automation and Applied Informatics, “Politehnica” University of Timisoara, Bd. V. Parvan 2, Timisoara, Romania (e-mail: stefan.preitl@aut.upt.ro)
    **** School of Information Technology and Engineering, University of Ottawa, 800 King Edward, Ottawa, Ontario, K1N 6N5 Canada (e-mail: petriu@site.uottawa.ca)
    ***** Department of Automation and Applied Informatics, “Politehnica” University of Timisoara, Bd. V. Parvan 2, Timisoara, Romania (e-mail: mircea.radac@aut.upt.ro)
    ****** Department of Automation and Applied Informatics, “Politehnica” University of Timisoara, Bd. V. Parvan 2, Timisoara, Romania (e-mail: adi11p@yahoo.com)


    Abstract: This paper presents aspects concerning the stable design of fuzzy control solutions for the position control of an electromagnetic actuated clutch. The mathematical modelling of the plant is first solved offering the plant models expressed as first principle nonlinear models, linearized models, dynamic Takagi-Sugeno fuzzy models and Tensor Product models derived from Linear Parameter-Varying models. The PI controllers are tuned by the Modulus Optimum method. The Takagi-Sugeno PI-fuzzy controllers are tuned on the basis of the modal equivalence principle which maps the parameters of the linear PI controllers onto the parameters of the fuzzy ones. The Takagi-Sugeno state feedback fuzzy controllers are designed by Parallel Distributed Compensation to obtain the state feedback gain matrices in the consequents of the rules. The stability of all fuzzy control systems is guaranteed in terms of deriving stability conditions expressed as Linear Matrix Inequalities (LMIs) and solving the LMIs.
    Keywords: Electromagnetic actuated clutch, stable fuzzy control, Takagi-Sugeno fuzzy models, Takagi-Sugeno PI-fuzzy controllers, Tensor Product models.

  10. SLOPE RESTRICTIONS. MULTIPLIERS. STABILITY INEQUALITIES (pp. 61-65)

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


    Abstract: It is considered an overview of the frequency domain inequalities for the absolute stability of the systems with monotone and slope restricted nonlinearities. It appears that the same type of multiplier is associated with different augmentations of the state space and this fact explains various additional assumptions accompanying the stability inequalities. These inequalities are applied to the PIO II problem in aircraft dynamics where the feedback structure of the absolute stability contains the saturation nonlinearity which is both non-decreasing and slope restricted.
    Keywords: Absolute stability, Multipliers, Slope restrictions, Frequency domain.

  11. CONTROL TWO-WAY MONITORING PROCESS USING METRO ETHERNET FORUM (pp. 66-72)

    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: Metro Ethernet Forum (MEF) protocol is described as a bridged-Ethernet per-VLAN (Virtual Local Area Network) implementation and with the help of Ping and Hello packets estimates service assurance (SA) metrics and specific connectivity tests. MEF protocol is an Operations, Administration, and Maintenance (OAM) feature. MEF is a powerful tool for network engineers to test real-time connectivity, latency, jitter, and frame-loss parameters on the bridged network, without higher-layer implementations. In this paper, new commands were developed for monitoring two-way connectivity, jitter, frameloss, and latency. Also, there is an example on how to use these commands. Keywords: domain, jitter, frame delay, frame-loss, latency, command.

  12. CONTROL SYSTEM FOR AMMONIA SYNTHESIS COLUMN (pp. 73-80)

    Matei Vinatoru
    Automation Department, University of Craiova, Al. I. Cuza Street, No. 13, 1100-Craiova, ROMANIA, (e-mail: vinatoru@automation.ucv.ro)


    Abstract: The paper presents the possibilities of simulation of steady and dynamic regimes for ammonia synthesis columns. We present the possibilities of study of the dynamic regimes for automatic control of the temperature in catalyst layers and propose an advanced control structure using the fresh gas flows between catalyst layers as commands. We also present the possibilities of optimization of the column steady states to obtain a higher conversion factor using the control of gas flows between the catalyst layers. This optimization algorithm is part of the main advanced control program for the synthesis column.
    Keywords: Advanced control system, modeling, simulation, ammonia plant synthesis.