WorldWideScience

Sample records for based control strategies

  1. ROBUST INTERNAL MODEL CONTROL STRATEGY BASED PID CONTROLLER FOR BLDCM

    Directory of Open Access Journals (Sweden)

    A.PURNA CHANDRA RAO

    2010-11-01

    Full Text Available All the closed loop control system requires the controller for improvement of transient response of the error signal. Though the tuning of PID controller in real time is bit difficult and moreover it lacks the disturbance rejection capability. This paper presents a tuning of PID parameters based on internal model strategy. The advantageous of the proposed control strategy is well described in the paper. To test the validity of the proposed control, it is implemented in brushless dc motor drive. The mathematical model of brushless dc motor (BLDC is presented for control design. In addition the robustness of the control strategy is discussed. The proposed control strategy possesses good transient responses and good load disturbance response. In addition, the proposed control strategy possesses good tracking ability. To test the effectiveness of the proposed strategy, the BLDC is represented in transfer function model and later implemented in test system. The results are presented to validate the proposed control strategy for BLDC drive.

  2. UAV Robust Strategy Control Based on MAS

    Directory of Open Access Journals (Sweden)

    Jian Han

    2014-01-01

    Full Text Available A novel multiagent system (MAS has been proposed to integrate individual UAV (unmanned aerial vehicle to form a UAV team which can accomplish complex missions with better efficiency and effect. The MAS based UAV team control is more able to conquer dynamic situations and enhance the performance of any single UAV. In this paper, the MAS proposed and established combines the reacting and thinking abilities to be an initiative and autonomous hybrid system which can solve missions involving coordinated flight and cooperative operation. The MAS uses BDI model to support its logical perception and to classify the different missions; then the missions will be allocated by utilizing auction mechanism after analyzing dynamic parameters. Prim potential algorithm, particle swarm algorithm, and reallocation mechanism are proposed to realize the rational decomposing and optimal allocation in order to reach the maximum profit. After simulation, the MAS has been proved to be able to promote the success ratio and raise the robustness, while realizing feasibility of coordinated flight and optimality of cooperative mission.

  3. Control strategies for VSC-based HVDC transmission system

    DEFF Research Database (Denmark)

    Stan, Ana-Irina; Stroe, Daniel Ioan; Silva, Rodrigo Da

    2011-01-01

    Throughout this paper the modeling and control of the VSC-based HVDC systems are investigated and described. Two different control methods capable of controlling such systems are proposed. Both developed control strategies are implemented in the dq synchronous reference frame. In order to analyze...... the behavior of the developed VSC-based HVDC transmission system two study cases are carried out using MATLAB/Simulink. The results obtained from simulations show acceptable performances, of the proposed strategies, when changes in the reference parameters are considered. The active power flow between...... the converters is succesfully achieved while, the independent control of active and reactive power is also verified....

  4. Control Strategies for the DAB Based PV Interface System

    Science.gov (United States)

    El-Helw, Hadi M.; Al-Hasheem, Mohamed; Marei, Mostafa I.

    2016-01-01

    This paper presents an interface system based on the Dual Active Bridge (DAB) converter for Photovoltaic (PV) arrays. Two control strategies are proposed for the DAB converter to harvest the maximum power from the PV array. The first strategy is based on a simple PI controller to regulate the terminal PV voltage through the phase shift angle of the DAB converter. The Perturb and Observe (P&O) Maximum Power Point Tracking (MPPT) technique is utilized to set the reference of the PV terminal voltage. The second strategy presented in this paper employs the Artificial Neural Network (ANN) to directly set the phase shift angle of the DAB converter that results in harvesting maximum power. This feed-forward strategy overcomes the stability issues of the feedback strategy. The proposed PV interface systems are modeled and simulated using MATLAB/SIMULINK and the EMTDC/PSCAD software packages. The simulation results reveal accurate and fast response of the proposed systems. The dynamic performance of the proposed feed-forward strategy outdoes that of the feedback strategy in terms of accuracy and response time. Moreover, an experimental prototype is built to test and validate the proposed PV interface system. PMID:27560138

  5. Control Strategies for the DAB Based PV Interface System.

    Science.gov (United States)

    El-Helw, Hadi M; Al-Hasheem, Mohamed; Marei, Mostafa I

    2016-01-01

    This paper presents an interface system based on the Dual Active Bridge (DAB) converter for Photovoltaic (PV) arrays. Two control strategies are proposed for the DAB converter to harvest the maximum power from the PV array. The first strategy is based on a simple PI controller to regulate the terminal PV voltage through the phase shift angle of the DAB converter. The Perturb and Observe (P&O) Maximum Power Point Tracking (MPPT) technique is utilized to set the reference of the PV terminal voltage. The second strategy presented in this paper employs the Artificial Neural Network (ANN) to directly set the phase shift angle of the DAB converter that results in harvesting maximum power. This feed-forward strategy overcomes the stability issues of the feedback strategy. The proposed PV interface systems are modeled and simulated using MATLAB/SIMULINK and the EMTDC/PSCAD software packages. The simulation results reveal accurate and fast response of the proposed systems. The dynamic performance of the proposed feed-forward strategy outdoes that of the feedback strategy in terms of accuracy and response time. Moreover, an experimental prototype is built to test and validate the proposed PV interface system.

  6. Congestion Control Strategy for Opportunistic Network Based on Message Values

    Directory of Open Access Journals (Sweden)

    Deng-yin Zhang

    2014-05-01

    Full Text Available To solve the congestion problem in opportunistic networks, a congestion control strategy based on message deleting and transferring(DATM is proposed. The congested node calculates the storage value of each message according to the forwarding probability and TTL of message, then deletes the message with the minimum storage value and transfers the message with the minimum forwarding probability to neighboring nodes. The neighboring nodes calculate the receiving value of the message according to the forwarding probability and free buffer capacity of this message. The congested node transfers the message to the neighboring node with the maximum receiving value. The message will be deleted when there is no neighboring node to receive it. The algorithm is more targeted at deleting messages. Besides, it combines the strategy of transferring message. Therefore, it can deal with the congestion more efficiently. The message arrival rate is improved significantly and the end-to-end delay is also reduced to some extent.

  7. Energy Optimal Control Strategy of PHEV Based on PMP Algorithm

    Directory of Open Access Journals (Sweden)

    Tiezhou Wu

    2017-01-01

    Full Text Available Under the global voice of “energy saving” and the current boom in the development of energy storage technology at home and abroad, energy optimal control of the whole hybrid electric vehicle power system, as one of the core technologies of electric vehicles, is bound to become a hot target of “clean energy” vehicle development and research. This paper considers the constraints to the performance of energy storage system in Parallel Hybrid Electric Vehicle (PHEV, from which lithium-ion battery frequently charges/discharges, PHEV largely consumes energy of fuel, and their are difficulty in energy recovery and other issues in a single cycle; the research uses lithium-ion battery combined with super-capacitor (SC, which is hybrid energy storage system (Li-SC HESS, working together with internal combustion engine (ICE to drive PHEV. Combined with PSO-PI controller and Li-SC HESS internal power limited management approach, the research proposes the PHEV energy optimal control strategy. It is based on revised Pontryagin’s minimum principle (PMP algorithm, which establishes the PHEV vehicle simulation model through ADVISOR software and verifies the effectiveness and feasibility. Finally, the results show that the energy optimization control strategy can improve the instantaneity of tracking PHEV minimum fuel consumption track, implement energy saving, and prolong the life of lithium-ion batteries and thereby can improve hybrid energy storage system performance.

  8. Indoor biology pollution control based on system-based humidity priority control strategy

    Institute of Scientific and Technical Information of China (English)

    刘亚昱; 谢慧; 石博强

    2009-01-01

    Indoor biological contamination and HVAC system secondary contamination problems caused wide public concerns. Biological contamination control will be the next step to achieve better IAQ. The most efficient and safe way to control biological contamination was to limit relative humidity in HVAC system and conditioned environment in the range that is more unsuitable for microorganism to survive. In this paper,by referring to bio-clean project experiences,a system-based humidity priority control manner came into being by lowering outdoor air humidity ratio to eliminate all indoor latent load and using self recirculation units to bear indoor sensible load. Based on the whole-course residue humidity contaminant control concept,dynamic step models for coil and conditioned zone were developed to describe mass and energy conservation and transformation processes. Then,HVAC system and conditioned zone dynamic models were established on LabVIEW+Matlab platform to investigate optimized regulation types,input signatures and control logics. Decoupling between cooling and dehumidification processes can be achieved and a more simplified and stable control system can be acquired by the system-based humidity priority control strategy. Therefore,it was a promising way for controlling biological pollution in buildings in order to achieve better IAQ.

  9. Control strategy of maglev vehicles based on particle swarm algorithm

    Institute of Scientific and Technical Information of China (English)

    Hui Wang; Gang Shen; Jinsong Zhou

    2014-01-01

    Taking a single magnet levitation system as the object, a nonlinear numerical model of the vehicle-guide-way coupling system was established to study the levitation control strategies. According to the similarity in dynamics, the single magnet-guideway coupling system was simpli-fied into a magnet-suspended track system, and the corre-sponding hardware-in-loop test rig was set up using dSPACE. A full-state-feedback controller was developed using the levitation gap signal and the current signal, and controller parameters were optimized by particle swarm algorithm. The results from the simulation and the test rig show that, the proposed control method can keep the sys-tem stable by calculating the controller output with the full-state information of the coupling system, Step responses from the test rig show that the controller can stabilize the system within 0.15 s with a 2% overshot, and performs well even in the condition of violent external disturbances. Unlike the linear quadratic optimal method, the particle swarm algorithm carries out the optimization with the nonlinear controlled object included, and its optimized results make the system responses much better.

  10. Application of Fuzzy Control with Market-Based Control Strategy to Structures

    Directory of Open Access Journals (Sweden)

    Gang Li

    2013-01-01

    Full Text Available The market-based control as a control strategy is developed based on an analogy between the control force-energy source in the structural area and the supply demand in the free market. The optimal problem of control force from an actuator is transformed to that of the allocation resource in the market. Since the supply-demand relation model and iteration procedure for the optimal price solution are necessary and relatively hard to understand and perform for civil engineers, the fuzzy logical method is proposed in the framework of the market-based control to acquire an equivalent system corresponding to the market-based control method. An equivalent fuzzy logical rule is established through analyzing a single-degree-of-freedom system with the controller using the MBC strategy under earthquakes. The results show that the fuzzy logical method is able to also reduce the displacement and acceleration responses effectively similar to the MBC method, and the consumed computational time for the fuzzy logical method is obviously saved.

  11. An estimator-based distributed voltage-predictive control strategy for ac islanded microgrids

    DEFF Research Database (Denmark)

    Wang, Yanbo; Chen, Zhe; Wang, Xiongfei

    2015-01-01

    This paper presents an estimator-based voltage predictive control strategy for AC islanded microgrids, which is able to perform voltage control without any communication facilities. The proposed control strategy is composed of a network voltage estimator and a voltage predictive controller for ea...

  12. Multi-agent coordination strategy estimation method based on control domain

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    For estimation group competition and multiagent coordination strategy, this paper introduces a notion based on multiagent group. According to the control domain, it analyzes the multiagent strategy during competi tion in the macroscopic. It has been adopted in robot soccer and result enunciates that our method does not de pend on competition result. It can objectively quantitatively estimate coordination strategy.

  13. Enhanced LVRT Control Strategy for DFIG-Based WECS in Weak Grid

    DEFF Research Database (Denmark)

    Abulanwar, Elsayed; Chen, Zhe; Iov, Florin

    2013-01-01

    An enhanced coordinated low voltage ride-through, LVRT, control strategy for a Doubly-fed Induction generator (DFIG)-based wind energy conversion system, WECS, connected to a weak grid is presented in this paper. The compliance with the grid code commitments is also considered. A proposed decoupled...... the effectiveness of the proposed control strategy using MATLAB/SIMULINK platform....

  14. Decentralized Event-Based Communication Strategy on Leader-Follower Consensus Control

    OpenAIRE

    Duosi Xie; Xiaochun Yin; Jianquan Xie

    2016-01-01

    This paper addresses the leader-follower consensus problem of networked systems by using a decentralized event-based control strategy. The event-based control strategy makes the controllers of agents update at aperiodic event instants. Two decentralized event functions are designed to generate these event instants. In particular, the second event function only uses its own information and the neighbors’ states at their latest event instants. By using this event function, no continuous communi...

  15. Improving water management efficiency by using optimization-based control strategies: the Barcelona case study

    OpenAIRE

    2009-01-01

    This paper describes the application of model-based predictive control (MPC) techniques to the flow management in large-scale drinking water networks including a telemetry/telecontrol system. MPC technique is used to generate flow control strategies from the sources to the consumer areas to meet future demands, optimizing performance indexes associated to operational goals such as economic cost, network safety volumes and flow control stability. The designed management strategies are...

  16. Coordinated Power Control Strategy based on Primary-Frequency-Signaling for Islanded Microgrids

    DEFF Research Database (Denmark)

    Wu, Dan; Guerrero, Josep M.; Vasquez, Juan Carlos;

    2013-01-01

    In a flexible microgrid, the power regulation of each electronic-converter-based unit should be not only determined by the load demand, but also controlled according to the power and energy available in each unit. This paper proposes a coordinated control strategy in which each unit can operate i...... with virtual impedance and primary control based on droop method for modes changes. The four modes changes for operation of ESS and RES are illustrated. Finally, simulation results will be presented to demonstrate and validate the proposed control strategy.......In a flexible microgrid, the power regulation of each electronic-converter-based unit should be not only determined by the load demand, but also controlled according to the power and energy available in each unit. This paper proposes a coordinated control strategy in which each unit can operate...

  17. Design of a nonlinear backstepping control strategy of grid interconnected wind power system based PMSG

    Science.gov (United States)

    Errami, Y.; Obbadi, A.; Sahnoun, S.; Benhmida, M.; Ouassaid, M.; Maaroufi, M.

    2016-07-01

    This paper presents nonlinear backstepping control for Wind Power Generation System (WPGS) based Permanent Magnet Synchronous Generator (PMSG) and connected to utility grid. The block diagram of the WPGS with PMSG and the grid side back-to-back converter is established with the dq frame of axes. This control scheme emphasises the regulation of the dc-link voltage and the control of the power factor at changing wind speed. Besides, in the proposed control strategy of WPGS, Maximum Power Point Tracking (MPPT) technique and pitch control are provided. The stability of the regulators is assured by employing Lyapunov analysis. The proposed control strategy for the system has been validated by MATLAB simulations under varying wind velocity and the grid fault condition. In addition, a comparison of simulation results based on the proposed Backstepping strategy and conventional Vector Control is provided.

  18. Tumour chemotherapy strategy based on impulse control theory.

    Science.gov (United States)

    Ren, Hai-Peng; Yang, Yan; Baptista, Murilo S; Grebogi, Celso

    2017-03-06

    Chemotherapy is a widely accepted method for tumour treatment. A medical doctor usually treats patients periodically with an amount of drug according to empirical medicine guides. From the point of view of cybernetics, this procedure is an impulse control system, where the amount and frequency of drug used can be determined analytically using the impulse control theory. In this paper, the stability of a chemotherapy treatment of a tumour is analysed applying the impulse control theory. The globally stable condition for prescription of a periodic oscillatory chemotherapeutic agent is derived. The permanence of the solution of the treatment process is verified using the Lyapunov function and the comparison theorem. Finally, we provide the values for the strength and the time interval that the chemotherapeutic agent needs to be applied such that the proposed impulse chemotherapy can eliminate the tumour cells and preserve the immune cells. The results given in the paper provide an analytical formula to guide medical doctors to choose the theoretical minimum amount of drug to treat the cancer and prevent harming the patients because of over-treating.This article is part of the themed issue 'Horizons of cybernetical physics'.

  19. Observational Iinearization and tracking objective excitation control strategy based on phasor measurement unit

    Institute of Scientific and Technical Information of China (English)

    QIU Xiaoyan; LI Xingyuan; WANG Xiaoyan

    2007-01-01

    To improve the transient stability ofmultimachine power systems,observational linearization and tracking objective excitation control laws were derived from the phasor measurement unit (PMU),observational linearization,and tracking objective control theory based on synchronized coordinates and reference generator coordinates.The control strategies utilized real-time state variables obtained by PMU to linearize the state equations of the system,and then the linear optimal control strategy was used to design excitation controllers.The inaccuracy of the local linearization method and the complexity of the system models designed in the exact linearization method for nonlinear systems were avoided.Therefore,the control strategies were applied in real time.Simulation results show that the proposed method can improve the transient stability of power systems more efficiently than nonlinear optimal excitation control.

  20. Modeling and Backstepping-based Nonlinear Control Strategy for a 6 DOF Quadrotor Helicopter

    Institute of Scientific and Technical Information of China (English)

    Ashfaq Ahmad Mian; Wang Daobo

    2008-01-01

    In this article,a nonlinear model of an underactuated six degrees of freedom (6 DOF) quadrotor helicopter is derived on the basis of the Newton-Euler formalism.The derivation comprises determining equations of the motion of the quadrotor in three dimensions andapproximating the actuation forces through the modeling of aerodynamic coefficients and electric motor dynamics.The derived modelcomposed of translatioual and rotational subsystems is dynamically unstable,so a sequential nonlinear control strategy is used.The con-trol strategy includes feedback linearization coupled with a PD controller for the translational subsystem and a backstepping-based PID nonlinear controller for the rotational subsystem of the quadrotor.The performances of the nonlinear control method are evaluated by nonlinear simulation and the results demonstrate the effectiveness of the proposed control strategy for the quadrotor helicopter inquasi-stationary flights.

  1. Study on transient stability of wind turbine with induction generator based on variable pitch control strategy

    DEFF Research Database (Denmark)

    Zhao, B.; Li, H.; Han, L.

    2011-01-01

    In order to enhance and improve the transient stability of a grid-connected wind turbine generator system under the power grid fault, based on typical pitch control strategy of wind turbine, considering the wind turbine system oscillation caused by the drive-train shaft flexibility, Based on Matlab/Simulink...

  2. Effects of iterative learning based signal control strategies on macroscopic fundamental diagrams of urban road networks

    Science.gov (United States)

    Yan, Fei; Tian, Fuli; Shi, Zhongke

    2016-10-01

    Urban traffic flows are inherently repeated on a daily or weekly basis. This repeatability can help improve the traffic conditions if it is used properly by the control system. In this paper, we propose a novel iterative learning control (ILC) strategy for traffic signals of urban road networks using the repeatability feature of traffic flow. To improve the control robustness, the ILC strategy is further integrated with an error feedback control law in a complementary manner. Theoretical analysis indicates that the ILC-based traffic signal control methods can guarantee the asymptotic learning convergence, despite the presence of modeling uncertainties and exogenous disturbances. Finally, the impacts of the ILC-based signal control strategies on the network macroscopic fundamental diagram (MFD) are examined. The results show that the proposed ILC-based control strategies can homogenously distribute the network accumulation by controlling the vehicle numbers in each link to the desired levels under different traffic demands, which can result in the network with high capacity and mobility.

  3. Velocity and Motion Control of a Self-balancing Vehicle based on a Cascade Control Strategy

    Directory of Open Access Journals (Sweden)

    Miguel Velazquez

    2016-06-01

    Full Text Available This paper presents balancing, velocity and motion control of a self-balancing vehicle. A cascade controller is implemented for both balancing control and angular velocity control. This controller is tested in simulations using a proposed mathematical model of the system. Motion control is achieved based on the kinematics of the robot. Control hardware is designed and integrated to implement the proposed controllers. Pitch is kept under 1° from the equilibrium position with no external disturbances. The linear cascade control is able to handle slight changes in the system dynamics, such as in the centre of mass and the slope on an inclined surface.

  4. Predictive control strategies for energy saving of hybrid electric vehicles based on traffic light information

    Directory of Open Access Journals (Sweden)

    Kaijiang YU

    2015-10-01

    Full Text Available As the conventional control method for hybrid electric vehicle doesn’t consider the effect of known traffic light information on the vehicle energy management, this paper proposes a model predictive control intelligent optimization strategies based on traffic light information for hybrid electric vehicles. By building the simplified model of the hybrid electric vehicle and adopting the continuation/generalized minimum residual method, the model prediction problem is solved. The simulation is conducted by using MATLAB/Simulink platform. The simulation results show the effectiveness of the proposed model of the traffic light information, and that the proposed model predictive control method can improve fuel economy and the real-time control performance significantly. The research conclusions show that the proposed control strategy can achieve optimal control of the vehicle trajectory, significantly improving fuel economy of the vehicle, and meet the system requirements for the real-time optimal control.

  5. A Novel Neutral Point Voltage Control Strategy for Three-Level NPC APF Based on SVPWM

    Directory of Open Access Journals (Sweden)

    Yao Xiaolong

    2015-01-01

    Full Text Available The unbalance of the neutral point voltage is an inherent problem of three-level neutral-point-clamped (NPC Active Power Filter (APF; this paper analyzes the causes of unbalanced neutral point voltage and studies the reason of the unbalance of the neutral point voltage. A novel neutral point voltage control strategy using Space Vector Pulse Width Modulation (SVPWM is proposed. The proposed strategy is based on the traditional SVPWM, by controlling the effect time of small vector, which can change the state of the midpoint voltage fluctuation, and the neutral point voltage can be maintained balance. The influence of the vector on neutral point balance is investigated in depth. Simulation results show the neutral point voltage balancing control strategy based on SPWM is effective.

  6. Self-organizing control strategy for asteroid intelligent detection swarm based on attraction and repulsion

    Science.gov (United States)

    An, Meiyan; Wang, Zhaokui; Zhang, Yulin

    2017-01-01

    The self-organizing control strategy for asteroid intelligent detection swarm, which is considered as a space application instance of intelligent swarm, is developed. The leader-follower model for the asteroid intelligent detection swarm is established, and the further analysis is conducted for massive asteroid and small asteroid. For a massive asteroid, the leader spacecraft flies under the gravity field of the asteroid. For a small asteroid, the asteroid gravity is negligible, and a trajectory planning method is proposed based on elliptic cavity virtual potential field. The self-organizing control strategy for the follower spacecraft is developed based on a mechanism of velocity planning and velocity tracking. The simulation results show that the self-organizing control strategy is valid for both massive asteroid and small asteroid, and the exploration swarm forms a stable configuration.

  7. Predictive-model-based dynamic coordination control strategy for power-split hybrid electric bus

    Science.gov (United States)

    Zeng, Xiaohua; Yang, Nannan; Wang, Junnian; Song, Dafeng; Zhang, Nong; Shang, Mingli; Liu, Jianxin

    2015-08-01

    Parameter-matching methods and optimal control strategies of the top-selling hybrid electric vehicle (HEV), namely, power-split HEV, are widely studied. In particular, extant research on control strategy focuses on the steady-state energy management strategy to obtain better fuel economy. However, given that multi-power sources are highly coupled in power-split HEVs and influence one another during mode shifting, conducting research on dynamic coordination control strategy (DCCS) to achieve riding comfort is also important. This paper proposes a predictive-model-based DCCS. First, the dynamic model of the objective power-split HEV is built and the mode shifting process is analyzed based on the developed model to determine the reason for the system shock generated. Engine torque estimation algorithm is then designed according to the principle of the nonlinear observer, and the prediction model of the degree of shock is established based on the theory of model predictive control. Finally, the DCCS with adaptation for a complex driving cycle is realized by combining the feedback control and the predictive model. The presented DCCS is validated on the co-simulation platform of AMESim and Simulink. Results show that the shock during mode shifting is well controlled, thereby improving riding comfort.

  8. Solution-based Chemical Strategies to Purposely Control the Microstructure of Functional Materials

    Institute of Scientific and Technical Information of China (English)

    Fei LIU; Congting SUN; Chenglin YAN; Dongfeng XUE

    2008-01-01

    Micro/nanostructured crystals with controlled architectures are desirable for many applications in optics, electronics, biology, medicine, and energy conversions. Low-temperature, aqueous chemical routes have been widely investigated for the synthesis of particles, and arrays of oriented nanorods and nanotubes. In this paper, based on the ideal crystal shapes predicted by the chemical bonding theory, we have developed some potential chemical strategies to tune the microstructure of functional materials, ZnS and Nb2O5 nanotube arrays, MgO wiskers and nestlike spheres, and cubic phase Cu2O microcrystals were synthesized here to elucidate these strategies. We describe their controlled crystallization processes and illustrate the detailed key factors controlling their growth by examining various reaction parameters. Current results demonstrate that our designed chemical strategies for tuning microstructure of functional materials are applicable to several technologically important materials, and therefore may be used as a versatile and effective route to the controllable synthesis of other inorganic functional materials.

  9. Coordinated Control Strategies of VSC-HVDC-Based Wind Power Systems for Low Voltage Ride Through

    Directory of Open Access Journals (Sweden)

    Xinyin Zhang

    2015-07-01

    Full Text Available The Voltage Source Converter-HVDC (VSC-HVDC system applied to wind power generation can solve large scale wind farm grid-connection and long distance transmission problems. However, the low voltage ride through (LVRT of the VSC-HVDC connected wind farm is a key technology issue that must be solved, and it is currently lacking an economic and effective solution. In this paper, a LVRT coordinated control strategy is proposed for the VSC-HVDC-based wind power system. In this strategy, the operation and control of VSC-HVDC and wind farm during the grid fault period is improved. The VSC-HVDC system not only provides reactive power support to the grid, but also effectively maintains the power balance and DC voltage stability by reducing wind-farm power output, without increasing the equipment investment. Correspondingly, to eliminate the influence on permanent magnet synchronous generator (PMSG-based wind turbine (WT systems, a hierarchical control strategy is designed. The speed and validity of the proposed LVRT coordinated control strategy and hierarchical control strategy were verified by MATLAB/Simulink simulations.

  10. Automatic Generation Control Strategy Based on Balance of Daily Electric Energy

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    An automatic generation control strategy based on balance of daily total electric energy is put forward. It makes the balance between actual total generated energy controlled by automatic generation system and planned total energy on base of area control error, and makes the actual 24-hour active power load curve to approach the planned load curve. The generated energy is corrected by velocity weighting factor so that it conducts dynamic regulation and reaches the speed of response. Homologous strategy is used according to the real-time data in the operation of automatic generation control. Results of simulation are perfect and power energy compensation control with ideal effect can be achieved in the particular duration.

  11. Tax Strategy Control

    DEFF Research Database (Denmark)

    Rossing, Christian Plesner

    2013-01-01

    This paper examines how a functional tax strategy impacts the management control system (MCS) in a multinational enterprise (MNE) facing transfer pricing tax risks. Based on case study findings it is argued that the MCS in a multinational setting is contingent upon the MNE's response to its tax...... environment. Moreover, the paper extends existing contingency-based theory on MCS by illustrating the role of inter-organisational network collaboration across MNE transfer pricing tax experts. This collaboration, caused by a widely dispersed tax knowledge base, fuels the formal interactive control system...

  12. Agent-based Cyber Control Strategy Design for Resilient Control Systems: Concepts, Architecture and Methodologies

    Energy Technology Data Exchange (ETDEWEB)

    Craig Rieger; Milos Manic; Miles McQueen

    2012-08-01

    The implementation of automated regulatory control has been around since the middle of the last century through analog means. It has allowed engineers to operate the plant more consistently by focusing on overall operations and settings instead of individual monitoring of local instruments (inside and outside of a control room). A similar approach is proposed for cyber security, where current border-protection designs have been inherited from information technology developments that lack consideration of the high-reliability, high consequence nature of industrial control systems. Instead of an independent development, however, an integrated approach is taken to develop a holistic understanding of performance. This performance takes shape inside a multiagent design, which provides a notional context to model highly decentralized and complex industrial process control systems, the nervous system of critical infrastructure. The resulting strategy will provide a framework for researching solutions to security and unrecognized interdependency concerns with industrial control systems.

  13. Do biological-based strategies hold promise to biofouling control in MBRs?

    KAUST Repository

    Malaeb, Lilian

    2013-10-01

    Biofouling in membrane bioreactors (MBRs) remains a primary challenge for their wider application, despite the growing acceptance of MBRs worldwide. Research studies on membrane fouling are extensive in the literature, with more than 200 publications on MBR fouling in the last 3 years; yet, improvements in practice on biofouling control and management have been remarkably slow. Commonly applied cleaning methods are only partially effective and membrane replacement often becomes frequent. The reason for the slow advancement in successful control of biofouling is largely attributed to the complex interactions of involved biological compounds and the lack of representative-for-practice experimental approaches to evaluate potential effective control strategies. Biofouling is driven by microorganisms and their associated extra-cellular polymeric substances (EPS) and microbial products. Microorganisms and their products convene together to form matrices that are commonly treated as a black box in conventional control approaches. Biological-based antifouling strategies seem to be a promising constituent of an effective integrated control approach since they target the essence of biofouling problems. However, biological-based strategies are in their developmental phase and several questions should be addressed to set a roadmap for translating existing and new information into sustainable and effective control techniques. This paper investigates membrane biofouling in MBRs from the microbiological perspective to evaluate the potential of biological-based strategies in offering viable control alternatives. Limitations of available control methods highlight the importance of an integrated anti-fouling approach including biological strategies. Successful development of these strategies requires detailed characterization of microorganisms and EPS through the proper selection of analytical tools and assembly of results. Existing microbiological/EPS studies reveal a number of

  14. Do biological-based strategies hold promise to biofouling control in MBRs?

    Science.gov (United States)

    Malaeb, Lilian; Le-Clech, Pierre; Vrouwenvelder, Johannes S; Ayoub, George M; Saikaly, Pascal E

    2013-10-01

    Biofouling in membrane bioreactors (MBRs) remains a primary challenge for their wider application, despite the growing acceptance of MBRs worldwide. Research studies on membrane fouling are extensive in the literature, with more than 200 publications on MBR fouling in the last 3 years; yet, improvements in practice on biofouling control and management have been remarkably slow. Commonly applied cleaning methods are only partially effective and membrane replacement often becomes frequent. The reason for the slow advancement in successful control of biofouling is largely attributed to the complex interactions of involved biological compounds and the lack of representative-for-practice experimental approaches to evaluate potential effective control strategies. Biofouling is driven by microorganisms and their associated extra-cellular polymeric substances (EPS) and microbial products. Microorganisms and their products convene together to form matrices that are commonly treated as a black box in conventional control approaches. Biological-based antifouling strategies seem to be a promising constituent of an effective integrated control approach since they target the essence of biofouling problems. However, biological-based strategies are in their developmental phase and several questions should be addressed to set a roadmap for translating existing and new information into sustainable and effective control techniques. This paper investigates membrane biofouling in MBRs from the microbiological perspective to evaluate the potential of biological-based strategies in offering viable control alternatives. Limitations of available control methods highlight the importance of an integrated anti-fouling approach including biological strategies. Successful development of these strategies requires detailed characterization of microorganisms and EPS through the proper selection of analytical tools and assembly of results. Existing microbiological/EPS studies reveal a number of

  15. Asynchronous update based networked predictive control system using a novel proactive compensation strategy.

    Science.gov (United States)

    Duan, Yingyao; Zuo, Xin; Liu, Jianwei

    2016-01-01

    Networked predictive control system (NPCS) has been proposed to address random delays and data dropouts in networked control systems (NCSs). A remaining challenge of this approach is that the controller has uncertain information about the actual control inputs, which leads to the predicted control input errors. The main contribution of this paper is to develop an explicit mechanism running in the distributed network nodes asynchronously, which enables the controller node to keep informed of the states of the actuator node without a priori knowledge about the network. Based on this mechanism, a novel proactive compensation strategy is proposed to develop asynchronous update based networked predictive control system (AUBNPCS). The stability criterion of AUBNPCS is derived analytically. A simulation experiment based on Truetime demonstrates the effectiveness of the scheme.

  16. A Fuzzy PI Speed Controller based on Feedback Compensation Strategy for PMSM

    Directory of Open Access Journals (Sweden)

    Ou Sheng

    2015-05-01

    Full Text Available in order to solve the problem of robustness or anti-disturbance of the traditional PI speed controller in the permanent magnet synchronous motor. A fuzzy PI speed controller based on load torque feedback compensation is proposed for the permanent magnet synchronous motor. The combination of fuzzy PI control strategy and load feedback compensation method can enhance the robustness and disturbance rejection of the speed loop. According to the validated results of simulation and experiments, by using this PMSM speed controller, the robustness of the system speed control was enhanced markedly, and the capacity of anti-disturbance was also improved significantly.

  17. Flow Control Strategy for the High Speed Network Based on Control Theory

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Design of an effective congestion control scheme is a hot topic in the development of computer network. The flow control scheme can adjust the packet sending rate in source host, thus effectively avoiding the network congestion. This paper proposes a new flow control scheme based on discrete control theory. The simulation results show that this method can adjust the sending rate and queue level in buffer rapidly and effectively. The method is easy to implement and applicable to high speed networks.

  18. Predictive control strategies for wind turbine system based on permanent magnet synchronous generator.

    Science.gov (United States)

    Maaoui-Ben Hassine, Ikram; Naouar, Mohamed Wissem; Mrabet-Bellaaj, Najiba

    2016-05-01

    In this paper, Model Predictive Control and Dead-beat predictive control strategies are proposed for the control of a PMSG based wind energy system. The proposed MPC considers the model of the converter-based system to forecast the possible future behavior of the controlled variables. It allows selecting the voltage vector to be applied that leads to a minimum error by minimizing a predefined cost function. The main features of the MPC are low current THD and robustness against parameters variations. The Dead-beat predictive control is based on the system model to compute the optimum voltage vector that ensures zero-steady state error. The optimum voltage vector is then applied through Space Vector Modulation (SVM) technique. The main advantages of the Dead-beat predictive control are low current THD and constant switching frequency. The proposed control techniques are presented and detailed for the control of back-to-back converter in a wind turbine system based on PMSG. Simulation results (under Matlab-Simulink software environment tool) and experimental results (under developed prototyping platform) are presented in order to show the performances of the considered control strategies.

  19. Receding Horizon-Based Dual Control Strategy for Pinpoint Planetary Landing

    Science.gov (United States)

    Cui, Ping-Yuan; Gao, Ai; Cui, Hu-Tao

    A receding horizon-based dual control strategy for a planetary landing mission is developed. This strategy introduces the receding horizon framework to solve the nonlinear dynamic path planning problem with the state constraint, which makes up for the defects of the typical polynomial guidance law when it is used in landing on a planet with irregular gravity. Furthermore, the trade-off between efficient control and reliable estimation is considered. The cost incurred by the system uncertainty is incorporated into the performance index. Furthermore a linear feedback control law is provided with the quadratic performance index considering the dual features, which takes advantage of the nonlinear coupling between observability and trajectory to overcome the lack of observability and achieve better estimation performance. By stochastically optimizing the landing trajectory obtained from the receding horizon based convex programming method, the overall performance of the guidance, navigation and control (GNC) system for landing on planets is improved.

  20. A Novel Relative Navigation Control Strategy Based on Relation Space Method for Autonomous Underground Articulated Vehicles

    Directory of Open Access Journals (Sweden)

    Fengqian Dou

    2016-01-01

    Full Text Available This paper proposes a novel relative navigation control strategy based on the relation space method (RSM for articulated underground trackless vehicles. In the RSM, a self-organizing, competitive neural network is used to identify the space around the vehicle, and the spatial geometric relationships of the identified space are used to determine the vehicle’s optimal driving direction. For driving control, the trajectories of the articulated vehicles are analyzed, and data-based steering and speed control modules are developed to reduce modeling complexity. Simulation shows that the proposed RSM can choose the correct directions for articulated vehicles in different tunnels. The effectiveness and feasibility of the resulting novel relative navigation control strategy are validated through experiments.

  1. Research on Sensorless control strategies for Vehicle stability using Fuzzy based EDC

    Directory of Open Access Journals (Sweden)

    A.Ravi

    2014-05-01

    Full Text Available This paper presents an efficient and robust control scheme of Fuzzy Logic Electronic Differential Controller (FLEDC for sensorless drive based electric vehicle. The proposed system consists of two Brushless DC motors (BLDC that ensure the drive of the two back driving wheels of an electric vehicle. Electronic differential controller (EDC ensures the maximum torque and it can control both the driving wheel independently to turn at different speeds in any curve according to the steering angle. The sensorless control strategies include back EMF zero crossing detection and third harmonic voltage integration. Fuzzy logic based EDC is used on these sensorless control strategies which optimizes the slip rate within the specified limit and thus enhances the vehicle stability The performances in terms of slip rate, current, Torque, back EMF are obtained by the proposed method and are compared with those obtained using conventional control method. By this comparative investigation, a suitable control strategy has been identified. The effectiveness and substantiation of these analysis are ascertained in the MATLAB/Simulink environment and also experimentally validated.

  2. Balancing Control Strategy for Li-Ion Batteries String Based on Dynamic Balanced Point

    Directory of Open Access Journals (Sweden)

    Dong-Hua Zhang

    2015-03-01

    Full Text Available The Li-ion battery is becoming the optimal choice for the Electric Vehicle’s (EV power supply. In order to protect the Li-ion battery from charging damage and to prolong the battery’s life, a special control strategy based on the dynamic balanced point along with a non-dissipative equalizer is presented. The main focus of the proposed control strategy is to insure that the individual cell of a battery pack will be rapidly, efficiently and simultaneously balanced, by adjusting equalizing current of each cell dynamically. In this paper, a model of a four series connected Li-ion batteries pack has been established to evaluate the proposed control strategy. Superior performance is demonstrated by the simulation and experiment.

  3. Event-Based Control Strategy for Mobile Robots in Wireless Environments

    Science.gov (United States)

    Socas, Rafael; Dormido, Sebastián; Dormido, Raquel; Fabregas, Ernesto

    2015-01-01

    In this paper, a new event-based control strategy for mobile robots is presented. It has been designed to work in wireless environments where a centralized controller has to interchange information with the robots over an RF (radio frequency) interface. The event-based architectures have been developed for differential wheeled robots, although they can be applied to other kinds of robots in a simple way. The solution has been checked over classical navigation algorithms, like wall following and obstacle avoidance, using scenarios with a unique or multiple robots. A comparison between the proposed architectures and the classical discrete-time strategy is also carried out. The experimental results shows that the proposed solution has a higher efficiency in communication resource usage than the classical discrete-time strategy with the same accuracy. PMID:26633412

  4. Event-Based Control Strategy for Mobile Robots in Wireless Environments.

    Science.gov (United States)

    Socas, Rafael; Dormido, Sebastián; Dormido, Raquel; Fabregas, Ernesto

    2015-12-02

    In this paper, a new event-based control strategy for mobile robots is presented. It has been designed to work in wireless environments where a centralized controller has to interchange information with the robots over an RF (radio frequency) interface. The event-based architectures have been developed for differential wheeled robots, although they can be applied to other kinds of robots in a simple way. The solution has been checked over classical navigation algorithms, like wall following and obstacle avoidance, using scenarios with a unique or multiple robots. A comparison between the proposed architectures and the classical discrete-time strategy is also carried out. The experimental results shows that the proposed solution has a higher efficiency in communication resource usage than the classical discrete-time strategy with the same accuracy.

  5. Event-Based Control Strategy for Mobile Robots in Wireless Environments

    Directory of Open Access Journals (Sweden)

    Rafael Socas

    2015-12-01

    Full Text Available In this paper, a new event-based control strategy for mobile robots is presented. It has been designed to work in wireless environments where a centralized controller has to interchange information with the robots over an RF (radio frequency interface. The event-based architectures have been developed for differential wheeled robots, although they can be applied to other kinds of robots in a simple way. The solution has been checked over classical navigation algorithms, like wall following and obstacle avoidance, using scenarios with a unique or multiple robots. A comparison between the proposed architectures and the classical discrete-time strategy is also carried out. The experimental results shows that the proposed solution has a higher efficiency in communication resource usage than the classical discrete-time strategy with the same accuracy.

  6. Improved Control Strategy for DFIG-based Wind Energy Conversion System during Grid Voltage Disturbances

    DEFF Research Database (Denmark)

    Zhu, Rongwu

    and rotor current. The degraded performances of the DFIG may reduce the life time of the drive train, affect the system stability, and even destroy the power converters. To improve the system performance, stability and reliability, it must improve the control strategy for the DFIG experiencing non...... flux is affected by the control strategy of the rotor current and stator time constant. The stator transient flux is harmful to the DFIG, because it may cause oscillations of the electromagnetic torque, stator or rotor current, DC-link voltage, and stator active and reactive power. On the basis...... the transient flux and then obtain constant electromagnetic torque, and stator active and reactive power as well. In addition, the stator and rotor current fast becomes sinusoidal. For the vectorbased DPC, a SM controller is used to control the stator active and reactive power. Based on the SM controller...

  7. Research on central heating system control strategy based on genetic algorithm

    Science.gov (United States)

    Ding, Sa; Yang, Jianhua; Lu, Wei; Duan, Zhipeng

    2017-03-01

    The central heating is a major way of warming in northeast China in winter, however, the traditional heating method is inefficient, intensifying the energy consumption. How to improve the heating efficiency and reduce energy waste attracts more and more attentions in our country. In this paper, the mathematical model of heat transfer station temperature control system was established based on the structure of central heating system. The feedforward-feedback control strategy was used to overcome temperature fluctuations caused by the pressurized heating exchange system. The genetic algorithm was used to optimize the parameters of PID controller and simulation results demonstrated that central heating temperature achieved well control effect and meet stabilization requirements.

  8. Control Strategy for Three Phase Voltage Source PWM Rectifier Based on the Space Vector Modulation

    Directory of Open Access Journals (Sweden)

    MILOUD, Y.

    2010-08-01

    Full Text Available This paper proposes the space vector pulse width modulation (SVPWM control scheme for three-phase voltage source PWM rectifier. The control system based on SVPWM includes two PI controllers which are used to regulate the AC currents and DC-link voltage. The proposed control can stabilize the minimum of the systems storage function at the desired equilibrium point determined by unity power factor and sinusoidal current on the AC side, and constant output voltage on the DC side. So the stable state performance and robustness against the load�s disturbance of PWM rectifiers are both improved. The simulation result shows feasibility of this strategy.

  9. A Lyapunov Stability Theory-Based Control Strategy for Three-Level Shunt Active Power Filter

    Directory of Open Access Journals (Sweden)

    Yijia Cao

    2017-01-01

    Full Text Available The three-phase three-wire neutral-point-clamped shunt active power filter (NPC-SAPF, which most adopts classical closed-loop feedback control methods such as proportional-integral (PI, proportional-resonant (PR and repetitive control, can only output 1st–25th harmonic currents with 10–20 kHz switching frequency. The reason for this is that the controller design must make a compromise between system stability and harmonic current compensation ability under the condition of less than 20 kHz switching frequency. To broaden the bandwidth of the compensation current, a Lyapunov stability theory-based control strategy is presented in this paper for NPC-SAPF. The proposed control law is obtained by constructing the switching function on the basis of the mathematical model and the Lyapunov candidate function, which can avoid introducing closed-loop feedback control and keep the system globally asymptotically stable. By means of the proposed method, the NPC-SAPF has compensation ability for the 1st–50th harmonic currents, the total harmonic distortion (THD and each harmonic content of grid currents satisfy the requirements of IEEE Standard 519-2014. In order to verify the superiority of the proposed control strategy, stability conditions of the proposed strategy and the representative PR controllers are compared. The simulation results in MATLAB/Simulink (MathWorks, Natick, MA, USA and the experimental results obtained on a 6.6 kVA NPC-SAPF laboratory prototype validate the proposed control strategy.

  10. Model-based evaluation of an on-line control strategy for SBRs based on OUR and ORP measurements.

    Science.gov (United States)

    Corominas, Ll; Sin, G; Puig, S; Traore, A; Balaguer, M; Colprim, J; Vanrolleghem, P A

    2006-01-01

    Application of control strategies for existing wastewater treatment technologies becomes necessary to meet ever-stricter effluent legislations and reduce the associated treatment costs. In the case of SBR technology, controlling the phase scheduling is one of the key aspects of SBR operation. In this study a calibrated mechanistic model based on the ASM1 was used to evaluate an on-line control strategy for the SBR phase-scheduling and compare it with the SBR's performance using no control strategy. To evaluate the performance, reference indices relating to the effluent quality, the required energy for aeration and the treated wastewater volume were used. The results showed that it is possible to maintain optimal SBR performance in the studied system at minimal costs by on-line control of the length of the aerobic and anoxic phases.

  11. Stability Analysis and Control of DFIG Based Wind Turbine Using FBC Strategy

    Directory of Open Access Journals (Sweden)

    Majid Tavoosi

    2013-10-01

    Full Text Available Doubly fed induction generator has numerous advantages in wind power generation over other types of generators. Once a DFIG is subjected to a large voltage dip, a large rotor voltage induces in the rotor windings. This leads to a large transient current in rotor circuit and the dc-link overvoltage, and may block power electronic converter operation. This paper first discusses dynamic modeling of DFIG wind turbines with the stator flux orientation. Then, by small signal analysis, it is found that the dynamic behavior of the DFIG based WT during voltage dip, is strongly affected by the stator dynamics. Next, a nonlinear control strategy based on flatness is proposed to improve the DFIG transient performance. The main interest of this control method is the possibility to define the behavior of the state variable system in the steady state as well as in transients. Since the DFIG electrical dynamics are nonlinear; better control performance is achieved with nonlinear control, compared with the linear control scheme. The proposed approach stabilizes the stator dynamics through rotor and grid side filter voltage control. The results of time domain simulations validate the effectiveness the nonlinear control strategy during voltage dip of generator terminal.

  12. Assessment of control strategies for fault ride through of SCIG-based wind energy conversion systems

    Directory of Open Access Journals (Sweden)

    Manaullah

    2016-01-01

    Full Text Available With increasing penetration of wind energy into the power grid, researchers have started focusing more on control and coordination of wind energy conversion systems (WECS with the other components at system level, especially during fault. It is important to implement a suitable fault ride through control strategy to avoid tripping of the generators when the power system is subjected to voltage dips normally below 90% of nominal voltage. The dips below 90% may lead to a significant loss of generation and frequency collapse, followed by a blackout. This article implements and assesses the methodologies to deal with such situations for squirrel cage induction generator-based wind energy conversion systems employing fully rated power electronic converters. Three distinct control techniques—namely, balanced positive sequence control, positive negative sequence control, and dual current control—have been simulated and applied to grid side converter of SCIG-based WECS. The performance of all the three control strategies has been compared and presented in this work. During this study, the system is subjected to the most common unsymmetrical line to ground (LG fault and most severe symmetrical LLL fault on grid for the purpose of anaysis.

  13. National Drug Control Strategy, 2011

    Science.gov (United States)

    Office of National Drug Control Policy, 2011

    2011-01-01

    In May of 2010, President Obama released the Administration's inaugural "National Drug Control Strategy". Based on the premise that drug use and its consequences pose a threat not just to public safety, but also to public health, the 2010 "Strategy" represented the first comprehensive rebalancing of Federal drug control policy in the nearly 40…

  14. DSC: software tool for simulation-based design of control strategies applied to wastewater treatment plants.

    Science.gov (United States)

    Ruano, M V; Ribes, J; Seco, A; Ferrer, J

    2011-01-01

    This paper presents a computer tool called DSC (Simulation based Controllers Design) that enables an easy design of control systems and strategies applied to wastewater treatment plants. Although the control systems are developed and evaluated by simulation, this tool aims to facilitate the direct implementation of the designed control system to the PC of the full-scale WWTP (wastewater treatment plants). The designed control system can be programmed in a dedicated control application and can be connected to either the simulation software or the SCADA of the plant. To this end, the developed DSC incorporates an OPC server (OLE for process control) which facilitates an open-standard communication protocol for different industrial process applications. The potential capabilities of the DSC tool are illustrated through the example of a full-scale application. An aeration control system applied to a nutrient removing WWTP was designed, tuned and evaluated with the DSC tool before its implementation in the full scale plant. The control parameters obtained by simulation were suitable for the full scale plant with only few modifications to improve the control performance. With the DSC tool, the control systems performance can be easily evaluated by simulation. Once developed and tuned by simulation, the control systems can be directly applied to the full-scale WWTP.

  15. Correction factor based double model fuzzy logic control strategy of arc voltage in pulsed MIG welding

    Institute of Scientific and Technical Information of China (English)

    Wu Kaiyuan; Huang Shisheng; Meng Yongmin

    2005-01-01

    According to the feature of arc voltage control in welding steel using pulsed MIG welding, a correction factor based double model fuzzy logic controller (FLC) was developed to realize the arc voltage control by means of arc voltage feedback.When the error of peak arc voltage was great, a coarse adjusting fuzzy logic control rules with correction factor was designed,in the controller, the peak arc voltage was controlled by the wire feeding speed by means of arc voltage feedback. When the error of peak arc voltage was small, a fine adjusting fuzzy logic control rules with correction factor was designed, in this controller, the peak arc voltage was controlled by the background time by means of arc voltage feedback. The FLC was realized in a Look-Up Table ( LUT) method. Experiments had been carried out aiming at implementing the control strategy to control the arc length change in welding process. Experimental results show that the controller proposed enables the consistency of arc length and the stabolity of arc voltage and welding process to be achieved in pulsed MIG welding process.

  16. An adaptive fuzzy-sliding lateral control strategy of automated vehicles based on vision navigation

    Science.gov (United States)

    Guo, Jinghua; Li, Linhui; Li, Keqiang; Wang, Rongben

    2013-10-01

    Lateral control is considered to be one of the toughest challenges in the development of automated vehicles due to their features of nonlinearities, parametric uncertainties and external disturbances. In order to overcome these difficulties, an adaptive fuzzy-sliding mode control strategy used for lateral control of vision-based automated vehicles is proposed in this paper. First, a vision algorithm is designed to provide accurate location information of vehicle relative to reference path. Then, an adaptive fuzzy-sliding mode lateral controller is proposed to counteract parametric uncertainties and strong nonlinearities, and the asymptotic stability of the closed-loop lateral control system is proven by the Lyapunov theory. Finally, experimental results indicate that the proposed algorithm can achieve favourable tracking performance, and it has strong robustness.

  17. Experimental testing of axial induction based control strategies for wake control and wind farm optimization

    Science.gov (United States)

    Bartl, J.; Sætran, L.

    2016-09-01

    In state-of-the-art wind farms each turbine is controlled individually aiming for optimum turbine power not considering wake effects on downstream turbines. Wind farm control concepts aim for optimizing the overall power output of the farm taking wake interactions between the individual turbines into account. This experimental wind tunnel study investigates axial induction based control concepts. It is examined how the total array efficiency of two in-line model turbines is affected when the upstream turbine's tip speed ratio (λcontrol) or blade pitch angle (β-control) is modified. The focus is particularly directed on how the wake flow behind the upstream rotor is affected when its axial induction is reduced in order to leave more kinetic energy in the wake to be recovered by a downstream turbine. It is shown that the radial distribution of kinetic energy in the wake area can be controlled by modifying the upstream turbine's tip speed ratio. By pitching out the upstream turbine's blades, however, the available kinetic energy in the wake is increased at an equal rate over the entire blade span. Furthermore, the total array efficiency of the two turbine setup is mapped depending on the upstream turbines tip speed ratio and pitch angle. For a small turbine separation distance of x/D=3 the downstream turbine is able to recover the major part of the power lost on the upstream turbine. However, no significant increase in the two-turbine array efficiency is achieved by altering the upstream turbine's operation point away from its optimum.

  18. A multi-mode operation control strategy for flexible microgrid based on sliding-mode direct voltage and hierarchical controls.

    Science.gov (United States)

    Zhang, Qinjin; Liu, Yancheng; Zhao, Youtao; Wang, Ning

    2016-03-01

    Multi-mode operation and transient stability are two problems that significantly affect flexible microgrid (MG). This paper proposes a multi-mode operation control strategy for flexible MG based on a three-layer hierarchical structure. The proposed structure is composed of autonomous, cooperative, and scheduling controllers. Autonomous controller is utilized to control the performance of the single micro-source inverter. An adaptive sliding-mode direct voltage loop and an improved droop power loop based on virtual negative impedance are presented respectively to enhance the system disturbance-rejection performance and the power sharing accuracy. Cooperative controller, which is composed of secondary voltage/frequency control and phase synchronization control, is designed to eliminate the voltage/frequency deviations produced by the autonomous controller and prepare for grid connection. Scheduling controller manages the power flow between the MG and the grid. The MG with the improved hierarchical control scheme can achieve seamless transitions from islanded to grid-connected mode and have a good transient performance. In addition the presented work can also optimize the power quality issues and improve the load power sharing accuracy between parallel VSIs. Finally, the transient performance and effectiveness of the proposed control scheme are evaluated by theoretical analysis and simulation results.

  19. Enhanced LVRT Control Strategy for DFIG-Based WECS in Weak Grid

    DEFF Research Database (Denmark)

    Abulanwar, Elsayed; Chen, Zhe; Iov, Florin

    2013-01-01

    An enhanced coordinated low voltage ride-through, LVRT, control strategy for a Doubly-fed Induction generator (DFIG)-based wind energy conversion system, WECS, connected to a weak grid is presented in this paper. The compliance with the grid code commitments is also considered. A proposed decoupled...... double synchronous reference frame (DDSRF) current controller is adopted for the design of grid side converter, GSC, controller to counteract current oscillations during asymmetrical faults and tackle the DC link voltage run-away. For a precise detection of the grid voltage position even under severe...... voltage dips/unbalanced conditions, A DDSRF-PLL is proposed and analyzed to extract clean synchronization signal in order to improve the overall system performance. Moreover, a fast decomposition based positive and negative sequence algorithm is utilized for rapid fault detection and to engage the LVRT...

  20. Research on Improved Control Strategy for STATCOM Based on Virtual Matrix Method

    Directory of Open Access Journals (Sweden)

    Wang Xudong

    2016-01-01

    Full Text Available Fast and accurate detection of reactive current is the precondition for the realization of static synchronous compensator (STATCOM reactive power compensation and harmonic suppression. Aiming at deviation and delay of the traditional reactive current detection algorithm with phase-locked loop (PLL and low-pass filter (LPF of STATCOM, a novel improved reactive current detection algorithm without PLL is proposed, in which the virtual matrix (VM is built to replace the original PLL, and improved current average value filter is used to realize the function of LPF, so as to improve the real-time performance and robustness of reactive current detection. The realization process of VM detection method is derived in this paper, and improved control strategy for STATCOM is designed based on the VM detection method. Simulation analysis of the proposed detection algorithm and control strategy is conducted in Matlab platform so as to verify the correctness and effectiveness of the control strategy. The VM detection has the advantages of simple structure, fast response and easy for digital realization, which provides reference for the improvement of reactive power compensation precision for STATCOM.

  1. Study on the dynamic performance of a novel buck-boost matrix converter based on double-loop control strategy

    Science.gov (United States)

    Li, Qing; Zhang, Xiao-ping; Chen, Qi

    2011-12-01

    The dynamic performance of a novel Buck-Boost matrix converter (BBMC) based on double-loop control strategy is put forward in this paper. The fundamental principle of BBMC has been elaborated and the method of the double-loop control strategy has been built with Matlab, and then the dynamic performances of BBMC based on the double-loop control strategy are discussed. The results show that the output voltage and frequency can be almost constant with the BBMC and double-loop control strategy despite of the changeable input voltage and frequency. Moreover, a high-quality sine output wave with low harmonic distortion can be directly obtained without filtering. So it can be drawn that the BBMC based on the double-loop control strategy has perfectly dynamic performance and practical importance to the engineering.

  2. Costate Estimation of PMP-Based Control Strategy for PHEV Using Legendre Pseudospectral Method

    Directory of Open Access Journals (Sweden)

    Hanbing Wei

    2016-01-01

    Full Text Available Costate value plays a significant role in the application of PMP-based control strategy for PHEV. It is critical for terminal SOC of battery at destination and corresponding equivalent fuel consumption. However, it is not convenient to choose the approximate costate in real driving condition. In the paper, the optimal control problem of PHEV based on PMP has been converted to nonlinear programming problem. By means of KKT condition costate can be approximated as KKT multipliers of NLP divided by the LGL weights. A kind of general costate estimation approach is proposed for predefined driving condition in this way. Dynamic model has been established in Matlab/Simulink in order to prove the effectiveness of the method. Simulation results demonstrate that the method presented in the paper can deduce the closer value of global optimal value than constant initial costate value. This approach can be used for initial costate and jump condition estimation of PMP-based control strategy for PHEV.

  3. A Coherence Preservation Control Strategy in Cavity QED Based on Classical Quantum Feedback

    Directory of Open Access Journals (Sweden)

    Ming Li

    2013-01-01

    Full Text Available For eliminating the unexpected decoherence effect in cavity quantum electrodynamics (cavity QED, the transfer function of Rabi oscillation is derived theoretically using optical Bloch equations. In particular, the decoherence in cavity QED from the atomic spontaneous emission is especially considered. A feedback control strategy is proposed to preserve the coherence through Rabi oscillation stabilization. In the scheme, a classical quantum feedback channel for the quantum information acquisition is constructed via the quantum tomography technology, and a compensation system based on the root locus theory is put forward to suppress the atomic spontaneous emission and the associated decoherence. The simulation results have proved its effectiveness and superiority for the coherence preservation.

  4. Sincere-Strategy Preference-Based Approval Voting Fully Resists Constructive Control and Broadly Resists Destructive Control

    CERN Document Server

    Erdelyi, Gabor; Rothe, Joerg

    2008-01-01

    We study sincere-strategy preference-based approval voting (SP-AV), a system proposed by Brams and Sanver [Electoral Studies, 25(2):287-305, 2006], with respect to procedural control. In such control scenarios, an external agent seeks to change the outcome of an election via actions such as adding/deleting/partitioning either candidates or voters. SP-AV combines the voters' preference rankings with their approvals of candidates, and we adapt it here so as to keep its useful features with respect to approval strategies even in the presence of control actions. We prove that this system is computationally resistant (i.e., the corresponding control problems are NP-hard) to 19 out of 22 types of constructive and destructive control. Thus, SP-AV has more resistances to control, by three, than is currently known for any other natural voting system with a polynomial-time winner problem. In particular, SP-AV is (after Copeland voting, see Faliszewski et al. [AAIM-2008, Springer LNCS 5034, pp. 165-176, 2008]) the secon...

  5. Modern Control Strategies for Double-Fed Induction Generator Based Wind Turbine System

    DEFF Research Database (Denmark)

    Zhou, Dao; Song, Yipeng; Blaabjerg, Frede

    2016-01-01

    -through operation, as well as steady and safe operation during long-term distorted grid), control strategies are continuously evolving. This paper starts with a control strategy using the combined reactive power compensation from both the back-to-back power converters for their optimized lifetime distribution under...

  6. Modern Control Strategies of Doubly-Fed Induction Generator Based Wind Turbine System

    DEFF Research Database (Denmark)

    Zhou, Dao; Song, Yipeng; Blaabjerg, Frede

    2017-01-01

    -through operation, as well as steady and safe operation during long-term distorted grid), control strategies are continuously evolving. This paper starts with a control strategy using the combined reactive power compensation from both the back-to-back power converters for their optimized lifetime distribution under...

  7. CONTROL SYSTEM OF MAGNETIC BEARINGS BASED ON LINEAR QUADRATIC METHOD OF OPTIMAL CONTROL STRATEGY

    Institute of Scientific and Technical Information of China (English)

    Zhu Huangqiu

    2005-01-01

    A state equation for radical 4-degree-of-freedom active magnetic bearings is built, and the approach on how to use linear quadratic method of optical control theory to design a centralized and decentralized parameters control system is introduced, and also Matlab language is used to simulate and analyze. The simulation results have proved that the differences are small between centralized parameters and decentralized parameters control system. The conclusions of experiments have shown that decentralized controllers designed from optimal state feedback theory meet the requirements of active magnetic bearing system. The vibration amplitude of the rotor is about 20 μm when the speed of the rotor runs between 0 to 60 000 r/min. This method may be used in the study and design of controllers of magnetic bearings.

  8. Avian influenza control strategies

    Science.gov (United States)

    Control strategies for avian influenza in poultry vary depending on whether the goal is prevention, management, or eradication. Components used in control programs include: 1) education which includes communication, public awareness, and behavioral change, 2) changes to production and marketing sys...

  9. Hybrid LSA-ANN Based Home Energy Management Scheduling Controller for Residential Demand Response Strategy

    Directory of Open Access Journals (Sweden)

    Maytham S. Ahmed

    2016-09-01

    Full Text Available Demand response (DR program can shift peak time load to off-peak time, thereby reducing greenhouse gas emissions and allowing energy conservation. In this study, the home energy management scheduling controller of the residential DR strategy is proposed using the hybrid lightning search algorithm (LSA-based artificial neural network (ANN to predict the optimal ON/OFF status for home appliances. Consequently, the scheduled operation of several appliances is improved in terms of cost savings. In the proposed approach, a set of the most common residential appliances are modeled, and their activation is controlled by the hybrid LSA-ANN based home energy management scheduling controller. Four appliances, namely, air conditioner, water heater, refrigerator, and washing machine (WM, are developed by Matlab/Simulink according to customer preferences and priority of appliances. The ANN controller has to be tuned properly using suitable learning rate value and number of nodes in the hidden layers to schedule the appliances optimally. Given that finding proper ANN tuning parameters is difficult, the LSA optimization is hybridized with ANN to improve the ANN performances by selecting the optimum values of neurons in each hidden layer and learning rate. Therefore, the ON/OFF estimation accuracy by ANN can be improved. Results of the hybrid LSA-ANN are compared with those of hybrid particle swarm optimization (PSO based ANN to validate the developed algorithm. Results show that the hybrid LSA-ANN outperforms the hybrid PSO based ANN. The proposed scheduling algorithm can significantly reduce the peak-hour energy consumption during the DR event by up to 9.7138% considering four appliances per 7-h period.

  10. An Improved PSO-Based MPPT Control Strategy for Photovoltaic Systems

    Directory of Open Access Journals (Sweden)

    M. Abdulkadir

    2014-01-01

    Full Text Available This paper presents a control strategy proposed for power maximizing which is a critical mechanism to ensure power track is maximized. Many tracking algorithms have been proposed for this purpose. One of the more commonly used techniques is the incremental conductance method. In this paper, an improved particle swarm optimization- (IPSO- based MPPT technique for photovoltaic system operating under varying environmental conditions is proposed. The approach of linearly decreasing scheme for weighting factor and cognitive and social parameter is modified. The proposed control scheme can overcome deficiency and accelerate convergence of the IPSO-based MPPT algorithm. The approach is not only capable of tracking the maximum power point under uniform insolation state, but also able to find the maximum power point under fast changing nonuniform insolation conditions. The photovoltaic systematic process with control schemes is created using MATLAB Simulink to verify the effectiveness with several simulations being carried out and then compared with the conventional incremental conductance technique. Lastly, the effectiveness of the intended techniques is proven using real data obtained form previous literature. With the change in insolation and temperature portrait, it produces exceptional MPPT maximization. This shows that optimum performance is achieved using the intended method compared to the typical method.

  11. A Study on Control Strategy of Regenerative Braking in the Hydraulic Hybrid Vehicle Based on ECE Regulations

    Directory of Open Access Journals (Sweden)

    Tao Liu

    2013-01-01

    Full Text Available This paper establishes a mathematic model of composite braking in the hydraulic hybrid vehicle and analyzes the constraint condition of parallel regenerative braking control algorithm. Based on regenerative braking system character and ECE (Economic Commission of Europe regulations, it introduces the control strategy of regenerative braking in parallel hydraulic hybrid vehicle (PHHV. Finally, the paper establishes the backward simulation model of the hydraulic hybrid vehicle in Matlab/simulink and makes a simulation analysis of the control strategy of regenerative braking. The results show that this strategy can equip the hydraulic hybrid vehicle with strong brake energy recovery power in typical urban drive state.

  12. Evolve the Controller for Static Synchronous Series Compensator Based on Control Strategy of Sen Transformer

    Directory of Open Access Journals (Sweden)

    Raju Jayaraman

    2014-02-01

    Full Text Available Real and Reactive power flow in an alternating current transmission line can be independently controlled by connecting, to the transmission line, a series-compensating voltage, which is variable in magnitude and phase angle. The Static Synchronous Series Compensator (SSSC, a solid-state voltage source inverter (VSC coupled with a transformer, is connected in series with a transmission line. An SSSC injects an almost sinusoidal voltage, of variable magnitude, in series with a transmission line. This injected voltage is almost in quadrature with the line current, thereby emulating an inductive or a capacitive reactance in series with the transmission line. This emulated variable reactance, inserted by the injected voltage source, influences the electric power flow in the transmission line. In this report, an attempt is made to evolve the model of SSSC and VSC with preliminary studies for the controller design.

  13. The Study of Operation Modes and Control Strategies of a Multidirectional MC for Battery Based System

    Directory of Open Access Journals (Sweden)

    Saman Toosi

    2015-01-01

    Full Text Available To enhance the performance of stand-alone battery based system and to achieve the continuous power transmission, the behavior of multidirectional matrix converter (MDMC has been analyzed in different operation modes. A systematic method interfacing a renewable source, a storage battery, and a load is proposed for a stand-alone battery based power system (SABBPS to utilize the MDMC as PWM converter, inverter, or PWM converter and inverter in different operation modes. In this study, the Extended Direct Duty Pulse Width Modulation (EDDPWM technique has been applied to control the power flow path between the renewable source, load, and the battery. Corresponding to generator voltage, input frequency, and loads demands, several operating states and control strategies are possible. Therefore, the boundaries and distribution of operation modes are discussed and illustrated to improve the system performance. The mathematical equation of the EDDPWM under different operation modes has been derived to achieve the maximum voltage ratio in each mode. The theoretical and modulation concepts presented have been verified in simulation using MATLAB and experimental testing. Moreover, the THD, ripple, and power flow direction have been analyzed for output current to investigate the behavior of system in each operation mode.

  14. A new virtual-flux-vector based droop control strategy for parallel connected inverters in microgrids

    DEFF Research Database (Denmark)

    Hu, Jiefeng; Zhu, Jianguo; Qu, Yanqing

    2013-01-01

    Voltage and frequency droop method is commonly used in microgrids to achieve proper autonomous power sharing without rely on intercommunication systems. This paper proposes a new control strategy for parallel connected inverters in microgrid applications by drooping the flux instead of the inverter....... In addition, a small- signal model is developed in order to design the main control parameters and study the system dynamics and stability. The proposed control scheme includes a direct flux control (DFC) algorithm, which avoids the use of PI controllers and PWM modulators. Furthermore, in order to reduce...... the flux ripple, a model predictive control (MPC) scheme is integrated into the DFC. The obtained results shows that the proposed flux droop strategy can achieve active and reactive power sharing with much lower frequency deviation and better transient performance than the conventional droop method, thus...

  15. Self-Adaptive Strategy Based on Fuzzy Control Systems for Improving Performance in Wireless Sensors Networks.

    Science.gov (United States)

    Hernández Díaz, Vicente; Martínez, José-Fernán; Lucas Martínez, Néstor; del Toro, Raúl M

    2015-09-18

    The solutions to cope with new challenges that societies have to face nowadays involve providing smarter daily systems. To achieve this, technology has to evolve and leverage physical systems automatic interactions, with less human intervention. Technological paradigms like Internet of Things (IoT) and Cyber-Physical Systems (CPS) are providing reference models, architectures, approaches and tools that are to support cross-domain solutions. Thus, CPS based solutions will be applied in different application domains like e-Health, Smart Grid, Smart Transportation and so on, to assure the expected response from a complex system that relies on the smooth interaction and cooperation of diverse networked physical systems. The Wireless Sensors Networks (WSN) are a well-known wireless technology that are part of large CPS. The WSN aims at monitoring a physical system, object, (e.g., the environmental condition of a cargo container), and relaying data to the targeted processing element. The WSN communication reliability, as well as a restrained energy consumption, are expected features in a WSN. This paper shows the results obtained in a real WSN deployment, based on SunSPOT nodes, which carries out a fuzzy based control strategy to improve energy consumption while keeping communication reliability and computational resources usage among boundaries.

  16. Self-Adaptive Strategy Based on Fuzzy Control Systems for Improving Performance in Wireless Sensors Networks

    Directory of Open Access Journals (Sweden)

    Vicente Hernández Díaz

    2015-09-01

    Full Text Available The solutions to cope with new challenges that societies have to face nowadays involve providing smarter daily systems. To achieve this, technology has to evolve and leverage physical systems automatic interactions, with less human intervention. Technological paradigms like Internet of Things (IoT and Cyber-Physical Systems (CPS are providing reference models, architectures, approaches and tools that are to support cross-domain solutions. Thus, CPS based solutions will be applied in different application domains like e-Health, Smart Grid, Smart Transportation and so on, to assure the expected response from a complex system that relies on the smooth interaction and cooperation of diverse networked physical systems. The Wireless Sensors Networks (WSN are a well-known wireless technology that are part of large CPS. The WSN aims at monitoring a physical system, object, (e.g., the environmental condition of a cargo container, and relaying data to the targeted processing element. The WSN communication reliability, as well as a restrained energy consumption, are expected features in a WSN. This paper shows the results obtained in a real WSN deployment, based on SunSPOT nodes, which carries out a fuzzy based control strategy to improve energy consumption while keeping communication reliability and computational resources usage among boundaries.

  17. Supervisor control strategy of synchronizer for wet DCT based on online estimation of clutch drag torque

    Science.gov (United States)

    Lu, Tongli; Li, Hongkui; Zhang, Jianwu; Hao, Hongtao

    2016-01-01

    The objective of this paper is to improve the performance of the synchronizer control strategy by considering the effect of clutch drag torque. The research of synchronization process in wet dual clutch transmission is performed in this paper. The significant effect of clutch drag torque is analyzed by adding a complex clutch drag torque module to synchronizer model. This paper focuses on the development of original estimation method of clutch drag torque. The estimation method offers an effective way to obtain accurate clutch drag torque, and it is applied to develop a new supervisor control strategy. Results have demonstrated that the estimation method has satisfied efficiency and accuracy and the control strategy improves the performance of the synchronizer mechanism significantly.

  18. Optimal Control Strategy for Traffic Driven Epidemic Spreading Based on Community Structure

    Directory of Open Access Journals (Sweden)

    Fei Shao

    2013-01-01

    Full Text Available It is shown that community structure has a great impact on traffic transportation and epidemic spreading. The density of infected nodes and the epidemic threshold have been proven to have significant relationship with the node betweenness in traffic driven epidemic spreading method. In this paper, considering the impact of community structure on traffic driven epidemic spreading, an effective and novel strategy to control epidemic spreading in scale-free networks is proposed. Theoretical analysis shows that the new control strategy will obviously increase the ratio between the first and the second moments of the node betweenness distribution in scale-free networks. It is also found that the more accurate the community is identified, the stronger community structure the network has and the more efficient the control strategy is. Simulations on both computer-generated and real-world networks have confirmed the theoretical results.

  19. School-based strategies for oral health education of adolescents- a cluster randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Haleem Abdul

    2012-12-01

    Full Text Available Abstract Background Oral health education (OHE in schools has largely been imparted by dental professionals. Considering the substantial cost of this expert-led approach, the strategies relying on teachers, peer-leaders and learners themselves have also been utilized. However the evidence for comparative effectiveness of these strategies is lacking in the dental literature. The present study was conducted to compare the effectiveness of dentist-led, teacher-led, peer-led and self-learning strategies of oral health education. Methods A two-year cluster randomized controlled trial following a parallel design was conducted. It involved five groups of adolescents aged 10-11 years at the start of the study. The trial involved process as well as four outcome evaluations. The present paper discusses the findings of the study pertaining to the baseline and final outcome evaluation, both comprising of a self-administered questionnaire, a structured interview and clinical oral examination. The data were analyzed using Generalized Estimating Equations. Results All the three educator-led strategies of OHE had statistically higher mean oral health knowledge (OHK, oral health behavior (OHB, oral hygiene status (OHS and combined knowledge, behavior and oral hygiene status (KBS scores than the self-learning and control groups (p Conclusions The dentist-led, teacher-led and peer-led strategies of oral health education are equally effective in improving the oral health knowledge and oral hygiene status of adolescents. The peer-led strategy, however, is almost as effective as the dentist-led strategy and comparatively more effective than the teacher-led and self-learning strategies in improving their oral health behavior. Trail registration SRCTN39391017

  20. A novel model-based control strategy for aerobic filamentous fungal fed-batch fermentation processes

    DEFF Research Database (Denmark)

    Mears, Lisa; Stocks, Stuart M.; Albaek, Mads O.

    2017-01-01

    in a batch in a defined process time. In order to achieve this goal, it is important to maximize both the product concentration, and also the total final mass in the fed-batch system. To this end, we describe the development of a control strategy which aims to achieve maximum tank fill, while avoiding oxygen...... limited conditions. This requires a two stage approach: (i) calculation of the tank start fill; and (ii) on-line control in order to maximize fill subject to oxygen transfer limitations. First, a mechanistic model was applied off-line in order to determine the appropriate start fill for processes...... with four different sets of process operating conditions for the stirrer speed, headspace pressure, and aeration rate. The start fills were tested with eight pilot scale experiments using a reference process operation. An on-line control strategy was then developed, utilizing the mechanistic model which...

  1. Double loop control strategy with different time steps based on human characteristics.

    Science.gov (United States)

    Gu, Gwang Min; Lee, Jinoh; Kim, Jung

    2012-01-01

    This paper proposes a cooperative control strategy in consideration of the force sensitivity of human. The strategy consists of two loops: one is the intention estimation loop whose sampling time can be variable in order to investigate the effect of the sampling time; the other is the position control loop with fixed time step. A high sampling rate is not necessary for the intention estimation loop due to the bandwidth of the mechanoreceptors in humans. In addition, the force sensor implemented in the robot is sensitive to the noise induced from the sensor itself and tremor of the human. Multiple experiments were performed with the experimental protocol using various time steps of the intention estimation loop to find the suitable sampling times in physical human robot interaction. The task involves pull-and-push movement with a two-degree-of-freedom robot, and the norm of the interaction force was obtained for each experiment as the measure of the cooperative control performance.

  2. Control of a Uniform Step Asymmetrical 9-Level Inverter Based on Artificial Neural Network Strategy

    Directory of Open Access Journals (Sweden)

    Rachid Taleb

    2009-12-01

    Full Text Available A neural implementation of a harmonic elimination strategy for the control auniform step asymmetrical 9-level inverter is proposed and described in this paper. AMulti-Layer Perceptrons (MLP neural network is used to approximate the mappingbetween the modulation rate and the required switching angles. After learning, the neuralnetwork generates the appropriate switching angles for the inverter. This leads to a lowcomputational-cost neural controller which is therefore well suited for real-timeapplications. This neural approach is compared to the well-known Multi-Carrier Pulse-Width Modulation (MCPWM. Simulation results demonstrate the technical advantages ofthe neural implementation of the harmonic elimination strategy over the conventionalmethod for the control of an uniform step asymmetrical 9-level inverter. The approach isused to supply an asynchronous machine and results show that the neural method ensures ahighest quality torque by efficiently canceling the harmonics generated by the inverter.

  3. [The technological innovation strategy for quality control of Chinese medicine based on Big Data].

    Science.gov (United States)

    Li, Zhen-hao; Qian, Zhong-zhi; Cheng, Yi-yu

    2015-09-01

    The evolution of the quality control concepts of medical products within the global context and the development of the quality control technology of Chinese medicine are briefly described. Aimed at the bottlenecks in the regulation and quality control of Chinese medicine, using Big Data technology to address the significant challenges in Chinese medicine industry is proposed. For quality standard refinements and internationalization of Chinese medicine, a technological innovation strategy encompassing its methodology, and the R&D direction of the subsequent core technology are also presented.

  4. Stability analysis of autonomous space systems in the presence of large disturbances: A Lyapunov-based constrained control strategy.

    Science.gov (United States)

    Mazinan, A H

    2016-03-01

    The research addresses a Lyapunov-based constrained control strategy to deal with the autonomous space system in the presence of large disturbances. The aforementioned autonomous space system under control is first represented through a dynamics model and subsequently the proposed control strategy is fully investigated with a focus on the three-axis detumbling and the corresponding pointing mode control approaches. The three-axis detumbling mode control approach is designed to deal with the unwanted angular rates of the system to be zero, while the saturations of the actuators are taken into consideration. Moreover, the three-axis pointing mode control approach is designed in the similar state to deal with the rotational angles of the system to be desirable. The contribution of the research is mathematically made to propose a control law in connection with a new candidate of Lyapunov function to deal with the rotational angles and the related angular rates of the present autonomous space system with respect to state-of-the-art. A series of experiments are carried out to consider the efficiency of the proposed control strategy, as long as a number of benchmarks are realized in the same condition to verify and guarantee the strategy performance in both modes of control approaches.

  5. Enhanced control strategy for MMC-based STATCOM for unbalanced load compensation

    DEFF Research Database (Denmark)

    Nieves, M.; Maza, J.M.; Mauricio, J.M.;

    2014-01-01

    as required for load unbalance compensation. This paper proposes an improved balancing strategy for the delta configuration to overcome this situation based on the injection of a third harmonic zero sequence current. Simulation results have proved the effectiveness of the proposal even where different...

  6. Reliability of unstable periodic orbit based control strategies in biological systems

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Nagender; Singh, Harinder P. [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Hasse, Maria [Institut für Höchstleistungsrechnen, Universität Stuttgart, D-70569 Stuttgart (Germany); Biswal, B. [Cluster Innovation Center, University of Delhi, Delhi 110007 (India); Sri Venkateswara College, University of Delhi, Delhi 110021 (India)

    2015-04-15

    Presence of recurrent and statistically significant unstable periodic orbits (UPOs) in time series obtained from biological systems is now routinely used as evidence for low dimensional chaos. Extracting accurate dynamical information from the detected UPO trajectories is vital for successful control strategies that either aim to stabilize the system near the fixed point or steer the system away from the periodic orbits. A hybrid UPO detection method from return maps that combines topological recurrence criterion, matrix fit algorithm, and stringent criterion for fixed point location gives accurate and statistically significant UPOs even in the presence of significant noise. Geometry of the return map, frequency of UPOs visiting the same trajectory, length of the data set, strength of the noise, and degree of nonstationarity affect the efficacy of the proposed method. Results suggest that establishing determinism from unambiguous UPO detection is often possible in short data sets with significant noise, but derived dynamical properties are rarely accurate and adequate for controlling the dynamics around these UPOs. A repeat chaos control experiment on epileptic hippocampal slices through more stringent control strategy and adaptive UPO tracking is reinterpreted in this context through simulation of similar control experiments on an analogous but stochastic computer model of epileptic brain slices. Reproduction of equivalent results suggests that far more stringent criteria are needed for linking apparent success of control in such experiments with possible determinism in the underlying dynamics.

  7. Reliability of unstable periodic orbit based control strategies in biological systems

    Science.gov (United States)

    Mishra, Nagender; Hasse, Maria; Biswal, B.; Singh, Harinder P.

    2015-04-01

    Presence of recurrent and statistically significant unstable periodic orbits (UPOs) in time series obtained from biological systems is now routinely used as evidence for low dimensional chaos. Extracting accurate dynamical information from the detected UPO trajectories is vital for successful control strategies that either aim to stabilize the system near the fixed point or steer the system away from the periodic orbits. A hybrid UPO detection method from return maps that combines topological recurrence criterion, matrix fit algorithm, and stringent criterion for fixed point location gives accurate and statistically significant UPOs even in the presence of significant noise. Geometry of the return map, frequency of UPOs visiting the same trajectory, length of the data set, strength of the noise, and degree of nonstationarity affect the efficacy of the proposed method. Results suggest that establishing determinism from unambiguous UPO detection is often possible in short data sets with significant noise, but derived dynamical properties are rarely accurate and adequate for controlling the dynamics around these UPOs. A repeat chaos control experiment on epileptic hippocampal slices through more stringent control strategy and adaptive UPO tracking is reinterpreted in this context through simulation of similar control experiments on an analogous but stochastic computer model of epileptic brain slices. Reproduction of equivalent results suggests that far more stringent criteria are needed for linking apparent success of control in such experiments with possible determinism in the underlying dynamics.

  8. Optimization strategy integrity for watershed agricultural non-point source pollution control based on Monte Carlo simulation

    Science.gov (United States)

    Gong, Y.; Yu, Y. J.; Zhang, W. Y.

    2016-08-01

    This study has established a set of methodological systems by simulating loads and analyzing optimization strategy integrity for the optimization of watershed non-point source pollution control. First, the source of watershed agricultural non-point source pollution is divided into four aspects, including agricultural land, natural land, livestock breeding, and rural residential land. Secondly, different pollution control measures at the source, midway and ending stages are chosen. Thirdly, the optimization effect of pollution load control in three stages are simulated, based on the Monte Carlo simulation. The method described above is applied to the Ashi River watershed in Heilongjiang Province of China. Case study results indicate that the combined three types of control measures can be implemented only if the government promotes the optimized plan and gradually improves implementation efficiency. This method for the optimization strategy integrity for watershed non-point source pollution control has significant reference value.

  9. An Innovative Control Strategy to Improve the Fault Ride-Through Capability of DFIGs Based on Wind Energy Conversion Systems

    Directory of Open Access Journals (Sweden)

    Vandai Le

    2016-01-01

    Full Text Available An innovative control strategy is proposed for enhancing the low voltage ride-through (LVRT capability of a doubly fed induction generator based on wind energy conversion systems (DFIG-WECS. Within the proposed control method, the current control loops of the rotor side converter (RSC are developed based on passivity theory. The control scheme for the grid side converter (GSC is designed based on a two-term approach to keep the DC-link voltage close to a given value. The first term based on the maximal voltage of GSC is introduced in the GSC control loops as a reference reactive current. The second one reflecting the instantaneous unbalanced power flow between the RSC and GSC is also introduced in the GSC control loops as a disturbance considering the instantaneous power of the grid filter to compensate the instantaneous rotor power. The effectiveness of the proposed control strategy is verified via time domain simulation of a 2.0 MW-575 V DFIG-WECS using PSCAD/EMTP. Simulation results show that the control of the DFIG with the proposed approach can improve the LVRT capability better than with the conventional one.

  10. An adaptive control strategy of converter based DG to maintain protection coordination in distribution system

    DEFF Research Database (Denmark)

    Su, Chi; Liu, Zhou; Chen, Zhe

    2014-01-01

    Distributed generation (DG) is increasingly integrated into distribution systems due to its flexible onsite characteristic and low carbon emission. However, DG integration may change the fault current pattern in distribution systems, which may in turn degrade the performance and coordination...... of network protection devices. As a protection measure commonly used in distribution network, recloser-fuse coordination could suffer from this impact. Research work has been conducted to deal with this problem by modifying the control strategy of the DG converters during faults. These solutions generally...

  11. Occupant satisfaction with two blind control strategies

    DEFF Research Database (Denmark)

    Karlsen, Line Røseth; Heiselberg, Per Kvols; Bryn, Ida

    2015-01-01

    Highlights •Occupant satisfaction with two blind control strategies has been studied. •Control based on cut-off position of slats was more popular than closed slats. •Results from the study are helpful in development of control strategies for blinds. •The results give indications of how blinds...

  12. Neural network based semi-active control strategy for structural vibration mitigation with magnetorheological damper

    DEFF Research Database (Denmark)

    Bhowmik, Subrata

    2011-01-01

    to determine the damper current based on the derived optimal damper force. For that reason an inverse MR damper model is also designed based on the neural network identification of the particular rotary MR damper. The performance of the proposed controller is compared to that of an optimal pure viscous damper......-displacement trajectories. The proposed neural network controller is therefore trained based on data derived from these desired forcedisplacement curves, where the optimal relation between friction force level and response amplitude is determined explicitly by simply maximizing the damping ratio of the targeted vibration....... The top floor displacement and acceleration of the base excited shear frame structure are selected as the performance parameters of this comparison. It is found by the simulations that the proposed control design yields a reduction in the structural response compared to the viscous case....

  13. A brucellosis disease control strategy for the Kakheti region of the country of Georgia: an agent-based model.

    Science.gov (United States)

    Havas, K A; Boone, R B; Hill, A E; Salman, M D

    2014-06-01

    Brucellosis has been reported in livestock and humans in the country of Georgia with Brucella melitensis as the most common species causing disease. Georgia lacked sufficient data to assess effectiveness of the various potential control measures utilizing a reliable population-based simulation model of animal-to-human transmission of this infection. Therefore, an agent-based model was built using data from previous studies to evaluate the effect of an animal-level infection control programme on human incidence and sheep flock and cattle herd prevalence of brucellosis in the Kakheti region of Georgia. This model simulated the patterns of interaction of human-animal workers, sheep flocks and cattle herds with various infection control measures and returned population-based data. The model simulates the use of control measures needed for herd and flock prevalence to fall below 2%. As per the model output, shepherds had the greatest disease reduction as a result of the infection control programme. Cattle had the greatest influence on the incidence of human disease. Control strategies should include all susceptible animal species, sheep and cattle, identify the species of brucellosis present in the cattle population and should be conducted at the municipality level. This approach can be considered as a model to other countries and regions when assessment of control strategies is needed but data are scattered.

  14. Combustion Control System Design of Diesel Engine via ASPR based Output Feedback Control Strategy with a PFC

    Science.gov (United States)

    Mizumoto, Ikuro; Tsunematsu, Junpei; Fujii, Seiya

    2016-09-01

    In this paper, a design method of an output feedback control system with a simple feedforward input for a combustion model of diesel engine will be proposed based on the almost strictly positive real-ness (ASPR-ness) of the controlled system for a combustion control of diesel engines. A parallel feedforward compensator (PFC) design scheme which renders the resulting augmented controlled system ASPR will also be proposed in order to design a stable output feedback control system for the considered combustion model. The effectiveness of our proposed method will be confirmed through numerical simulations.

  15. On the comparison of stochastic model predictive control strategies applied to a hydrogen-based microgrid

    Science.gov (United States)

    Velarde, P.; Valverde, L.; Maestre, J. M.; Ocampo-Martinez, C.; Bordons, C.

    2017-03-01

    In this paper, a performance comparison among three well-known stochastic model predictive control approaches, namely, multi-scenario, tree-based, and chance-constrained model predictive control is presented. To this end, three predictive controllers have been designed and implemented in a real renewable-hydrogen-based microgrid. The experimental set-up includes a PEM electrolyzer, lead-acid batteries, and a PEM fuel cell as main equipment. The real experimental results show significant differences from the plant components, mainly in terms of use of energy, for each implemented technique. Effectiveness, performance, advantages, and disadvantages of these techniques are extensively discussed and analyzed to give some valid criteria when selecting an appropriate stochastic predictive controller.

  16. A source-based congestion control strategy for real-time video transport on IP network

    Science.gov (United States)

    Chen, Xia; Cai, Canhui

    2005-07-01

    The goal of this paper is to design a TCP friendly real-time video transport protocol that will not only utilize network resource efficiently, but also prevent network congestion from the real-time video transmitting effectively. To this end, we proposed a source based congestion control scheme to adapt video coding rate to the channel capacity of the IP network, including three stages: rate control, rate-adaptive video encoding, and rate shaping.

  17. Investigation of neural-net based control strategies for improved power system dynamic performance

    Energy Technology Data Exchange (ETDEWEB)

    Sobajic, D.J. [Electric Power Research Institute, Palo Alto, CA (United States)

    1995-12-31

    The ability to accurately predict the behavior of a dynamic system is of essential importance in monitoring and control of complex processes. In this regard recent advances in neural-net base system identification represent a significant step toward development and design of a new generation of control tools for increased system performance and reliability. The enabling functionality is the one of accurate representation of a model of a nonlinear and nonstationary dynamic system. This functionality provides valuable new opportunities including: (1) The ability to predict future system behavior on the basis of actual system observations, (2) On-line evaluation and display of system performance and design of early warning systems, and (3) Controller optimization for improved system performance. In this presentation, we discuss the issues involved in definition and design of learning control systems and their impact on power system control. Several numerical examples are provided for illustrative purpose.

  18. Differential Control Strategy based on an Equal Slip Rate for an All-wheel Electricdrive Underground Articulated Dumping Truck

    Directory of Open Access Journals (Sweden)

    Jin Chun

    2014-09-01

    Full Text Available A differential control strategy based on equal slip rates is introduced to improve the steering stability of an all-wheelelectric-drive underground articulated dumping truck. Steering kinematic and dynamic models of the truck are derived to describe the movement relationship and force of the driving wheels. In consideration of the difficulty of obtaining the absolute velocity for an all-wheel-drive truck, an acceleration sensor was set on a test truck, and a kalman filter was applied to obtain the actual value for the truck body. Simulation results for an equal-slip control strategy were compared with experimental results for an equal-torque control strategy. In the simulation, the four-wheel slip rate was 0.08 and the steering system of the truck was stable. The results verify that the equal-slip control strategy makes better use of the ground adhesion coefficient, is able to reasonably distribute drive power, notably reduces tire wear, and improves the use of driving power.

  19. A comparison of acceptance- and control-based strategies for coping with food cravings: an analog study.

    Science.gov (United States)

    Forman, Evan M; Hoffman, Kimberly L; McGrath, Kathleen B; Herbert, James D; Brandsma, Lynn L; Lowe, Michael R

    2007-10-01

    The present study utilized an analog paradigm to investigate the effectiveness of two strategies for coping with food cravings, which was theorized to be critical to the maintenance of weight loss. Ninety-eight undergraduate students were given transparent boxes of chocolate Hershey's Kisses and instructed to keep the chocolates with them, but not to eat them, for 48 h. Before receiving the Kisses, participants were randomized to receive either (a) no intervention, (b) instruction in control-based coping strategies such as distraction and cognitive restructuring, or (c) instruction in acceptance-based strategies such as experiential acceptance and defusion techniques. Measures included the Power of Food Scale (PFS; a measure of psychological sensitivity to the food environment), self-report ratings of chocolate cravings and surreptitiously recorded chocolate consumption. Results suggested that the effect of the intervention depended on baseline PFS levels, such that acceptance-based strategies were associated with better outcomes (cravings, consumption) among those reporting the highest susceptibility to the presence of food, but greater cravings among those who scored lowest on the PFS. It was observed that craving self-report measures predicted chocolate consumption, and baseline PFS levels predicted both cravings and consumption. Results are discussed in terms of the implications for weight loss maintenance strategies.

  20. T-S Fuzzy Model Based Control Strategy for the Networked Suspension Control System of Maglev Train

    Directory of Open Access Journals (Sweden)

    Guang He

    2015-01-01

    Full Text Available The control problem for the networked suspension control system of maglev train with random induced time delay and packet dropouts is investigated. First, Takagi-Sugeno (T-S fuzzy models are utilized to represent the discrete-time nonlinear networked suspension control system, and the parameters uncertainties of the nonlinear model have also been taken into account. The controllers take the form of parallel distributed compensation. Then, a sufficient condition for the stability of the networked suspension control system is derived. Based on the criteria, the state feedback fuzzy controllers are obtained, and the controller gains can be computed by using MATLAB LMI Toolbox directly. Finally, both the numerical simulations and physical experiments on the full-scale single bogie of CMS-04 maglev train have been accomplished to demonstrate the effectiveness of this proposed method.

  1. Adolescents with Asperger Syndrome Can Use a Mindfulness-Based Strategy to Control Their Aggressive Behavior

    Science.gov (United States)

    Singh, Nirbhay N.; Lancioni, Giulio E.; Singh, Angela D. A.; Winton, Alan S. W.; Singh, Ashvind N. A.; Singh, Judy

    2011-01-01

    Children and adolescents with Asperger syndrome occasionally exhibit aggressive behavior against peers and parents. In a multiple baseline design across subjects, three adolescents with Asperger syndrome were taught to use a mindfulness-based procedure called "Meditation on the Soles of the Feet" to control their physical aggression in the family…

  2. PSO-Based Voltage Control Strategy for Loadability Enhancement in Smart Power Grids

    Directory of Open Access Journals (Sweden)

    Heng-Yi Su

    2016-12-01

    Full Text Available This paper proposes a new voltage control methodology using the particle swarm optimization (PSO technique for smart grid loadability enhancement. The goal of this paper is to achieve reliable and efficient voltage profile/stability regulation in power grids. This methodology is based on the decouple power flow equations and the worst-case design technique. Specifically, the secondary voltage control (SVC problem is formulated as an L-infinity norm minimization problem which considers overall load voltage deviations in electrical power systems as an objective model, and the PSO technique is employed to determine a robust control action which aims to improve voltage profile and to enlarge transmission grid loadability by optimal coordinated control of VAR sources. The methodology was successfully tested on several IEEE benchmark systems.

  3. Performance Analysis of Data-Driven and Model-Based Control Strategies Applied to a Thermal Unit Model

    Directory of Open Access Journals (Sweden)

    Cihan Turhan

    2017-01-01

    Full Text Available The paper presents the design and the implementation of different advanced control strategies that are applied to a nonlinear model of a thermal unit. A data-driven grey-box identification approach provided the physically–meaningful nonlinear continuous-time model, which represents the benchmark exploited in this work. The control problem of this thermal unit is important, since it constitutes the key element of passive air conditioning systems. The advanced control schemes analysed in this paper are used to regulate the outflow air temperature of the thermal unit by exploiting the inflow air speed, whilst the inflow air temperature is considered as an external disturbance. The reliability and robustness issues of the suggested control methodologies are verified with a Monte Carlo (MC analysis for simulating modelling uncertainty, disturbance and measurement errors. The achieved results serve to demonstrate the effectiveness and the viable application of the suggested control solutions to air conditioning systems. The benchmark model represents one of the key issues of this study, which is exploited for benchmarking different model-based and data-driven advanced control methodologies through extensive simulations. Moreover, this work highlights the main features of the proposed control schemes, while providing practitioners and heating, ventilating and air conditioning engineers with tools to design robust control strategies for air conditioning systems.

  4. Evaluation of community - based strategies for Aedes aegypti control inside houses

    OpenAIRE

    Pérez Flórez, Mauricio; Ocampo, Clara Beatriz; González, Camila; Morales, Carlos A.; Wesson, Dawn; Apperson, Charles S.

    2009-01-01

    Introducción. Los virus del dengue transmitidos principalmente por el mosquito urbano Aedes aegypti, causan uno de los mayores problemas de salud pública que confrontan las ciudades tropicales. La aplicación de insecticidas ha sido la base para el control de mosquitos; sin embargo, su continuo uso ha servido para seleccionar individuos resistentes en las poblaciones de mosquitos. Otro método importante para el control involucra la participación comunitaria. Objetivo. Este estudio evaluó do...

  5. Model-Based Evaluation of Strategies to Control Brucellosis in China

    Science.gov (United States)

    Li, Ming-Tao; Sun, Gui-Quan; Zhang, Wen-Yi; Jin, Zhen

    2017-01-01

    Brucellosis, the most common zoonotic disease worldwide, represents a great threat to animal husbandry with the potential to cause enormous economic losses. Brucellosis has become a major public health problem in China, and the number of human brucellosis cases has increased dramatically in recent years. In order to evaluate different intervention strategies to curb brucellosis transmission in China, a novel mathematical model with a general indirect transmission incidence rate was presented. By comparing the results of three models using national human disease data and 11 provinces with high case numbers, the best fitted model with standard incidence was used to investigate the potential for future outbreaks. Estimated basic reproduction numbers were highly heterogeneous, varying widely among provinces. The local basic reproduction numbers of provinces with an obvious increase in incidence were much larger than the average for the country as a whole, suggesting that environment-to-individual transmission was more common than individual-to-individual transmission. We concluded that brucellosis can be controlled through increasing animal vaccination rates, environment disinfection frequency, or elimination rates of infected animals. Our finding suggests that a combination of animal vaccination, environment disinfection, and elimination of infected animals will be necessary to ensure cost-effective control for brucellosis. PMID:28287496

  6. MPPT Algorithm for Small Wind Systems based on Speed Control Strategy

    Directory of Open Access Journals (Sweden)

    Ciprian VLAD

    2008-07-01

    Full Text Available This paper presents experimental results of an autonomous low-power wind energy conversion system (WECS, based on a permanent-magnet synchronous generator (PMSG connected directly to the wind turbine. The purpose of this paper is to present an improving method for MPPT (Maximum Power Point Tracking algorithm based shaft rotational speed optimal control. The proposed method concern the variable delay compensation between measured wind speed from anemometer and wind shaft rotational speed proportional signal. Experimental results aiming to prove the efficiency of the proposed method are presented.

  7. A Distributed Control Strategy Based on DC Bus Signaling for Modular Photovoltaic Generation Systems With Battery Energy Storage

    DEFF Research Database (Denmark)

    Sun, Kai; Zhang, Li; Xing, Yan

    2011-01-01

    Modular generation system, which consists of modular power conditioning converters, is an effective solution to integrate renewable energy sources with conventional utility grid to improve reliability and efficiency, especially for photovoltaic generation. A distributed control strategy based...... on improved dc bus signaling is proposed for a modular photovoltaic (PV) generation system with battery energy storage elements. In this paper, the modular PV generation system is composed of three modular dc/dc converters for PV arrays, two grid-connected dc/ac converters, and one dc/dc converter for battery......, grid-connected inversion, and islanding with constant voltage (CV) generation.The power balance of the system under extreme conditions such as the islanding operation with a full-charged battery is taken into account in this control strategy. The dc bus voltage level is employed as an information...

  8. Tracking control strategy for the optoelectronic system on the flexible suspended platform based on backstepping method

    Science.gov (United States)

    Yu, Wei; Ma, Jiaguang; Xiao, Jing

    2012-10-01

    To improve the optoelectronic tracking ability and rope-hanged platform attitude stability, against the interact effect between rope-hanged platform and optoelectronic system during system tracking process, the optoelectronic system fixed on rope hanged platform simplified dynamic model, according to the system's Lagrange dynamic model, was established. Backstepping method was employed to design an integrated controller for both optoelectronic system azimuth direction steering and platform attitude stabilizing. To deal with model's uncertainty and disturbance, a sliding mode controller form based exponential reaching law was adopted to structure the integrated controller. Simulation experiments simulated an optoelectronic system with 600mm caliber telescope, whose inertia fluctuation is 6%. The maximal control moment is 15Nm. And the external disturbance and internal friction effected together. When the line of sight(LOS) azimuth angular input is a step signal with 1rad amplitude, the response's overshoot is 6%, and the response time is 6.2s, and the steady state error is less than 4×10-4rad. When the input is a sinusoidal signal of 0.2rad amplitude with 0.0318Hz frequency, the LOS azimuth angular error amplitude is 5. 6×10-4rad. It is concluded that the controller designed in this article has excellent ability and can ensure the system's stability.

  9. Adaptive Fuzzy PID Based Control Strategy For 3Phase 4Wire Shunt Active Filter To Mitigate Current Harmonics Of Grid Interconnection Of Renewable Energy Based Distribution System

    Directory of Open Access Journals (Sweden)

    Kaleemullah

    2016-06-01

    Full Text Available This paper presents a new control strategy for controlling the shunt active power filter to compensate reactive power and to reduce the unwanted harmonics in the grid current. Shunt active filter act as a current source which is connected in parallel with a non-linear load and controlled to produce the required compensating current. The proposed control strategy is based on the fuzzy PID controller which is used for determining the reference compensating currents of the three-phase shunt active power filters. Simulations are carried out using MATLAB/SIMULINK to verify the performance of the proposed controller. The output shows the controller has fast dynamic response high accuracy of tracking DC voltage reference and robust to load parameters variations.

  10. Control strategy of shortcut nitrification

    Institute of Scientific and Technical Information of China (English)

    LU Gang; ZHENG Ping; JIN Ren-cun; QAISAR Mahmood

    2006-01-01

    Shortcut nitrification for ammonium-rich wastewater is energy-saving and cost-effective procedure that has become one of the hotspots in the field of biological denitrogenation. An orthogonal experiment was performed to study the combined effects of operational parameters on the performance of internal-loop airlift bioreactor for shortcut nitrification. The optimum operational parameters for the shortcut nitrification were found as temperature 35 ℃, pH 8.0, dissolved oxygen concentration 1.0 mg/L, ammonium concentration 4 mmol/L and HRT 16 h, which have different influence on the performance of shortcut nitrification reactor. The pH, temperature and dissolved oxygen concentration have significant bearing on the process. The results showed that the shortcut nitrification reactor could be successfully started up within 42 d, and the reactor performance is steady with minimum NO2-/NOx- of 85.2% , maximum 93.4% and average value of 91.4% in effluent. Based on the analysis of experimental data, a new control strategy named "priority + combination" for shortcut nitrification was suggested. Through this strategy, the startup and operation of shortcut nitrification for ammonium-rich sludge digester liquids were optimized. The control strategy works well to keep the reactor operation in steady state and in achieving high-efficiency for shortcut nitrification.

  11. An Energy-Based Control Strategy for Battery Energy Storage Systems: A Case Study on Microgrid Applications

    Directory of Open Access Journals (Sweden)

    Rui Hou

    2017-02-01

    Full Text Available Battery energy storage systems (BESSs with proportional-integral (PI control methods have been widely studied in microgrids (MGs. However, the performance of PI control methods might be unsatisfactory for BESSs due to the nonlinear characteristics of the system. To overcome this problem, an energy-based (EB control method is applied to control the converter of a BESS in this study. The EB method is a robust nonlinear control method based on passivity theory with good performance in both transient and steady states. The detailed design process of the EB method in the BESS by adopting an interconnection and damping assignment (IDA strategy is described. The design process comprises three steps: the construction of the port-controlled Hamiltonian model, the determination of the equilibrium point and the solution of the undetermined matrix. In addition, integral action is combined to eliminate the steady state error generated by the model mismatch. To establish the correctness and validity of the proposed method, we implement several case simulation studies based on a test MG system and compare the control performance of the EB and PI methods carefully. The case simulation results demonstrate that the EB method has better tracking and anti-disturbance performance compared with the classic PI method. Moreover, the proposed EB method shows stronger robustness to the uncertainty of system parameters.

  12. Fuzzy Logic Controller Based Distributed Generation Integration Strategy for Stochastic Performance Improvement

    Directory of Open Access Journals (Sweden)

    Jagdish Prasad Sharma

    2016-01-01

    Full Text Available In the restructured environment, distributed generation (DG is considered as a very promising option due to a high initial capital cost of conventional plants, environmental concerns, and power shortage. Apart from the above, distributed generation (DG has also abilities to improve performance of feeder. Most of the distribution feeders have radial structure, which compel to observe the impact of distributed generations on feeder performance, having different characteristics and composition of time varying static ZIP load models. Two fuzzy-based expert system is proposed for selecting and ranking the most appropriated periods to an integration of distributed generations with a feeder. Madami type fuzzy logic controller was developed for sizing of distributed generation, whereas Sugeno type fuzzy logic controller was developed for the DG location. Input parameters for Madami fuzzy logic controller are substation reserve capacity, feeder power loss to load ratio, voltage unbalance, and apparent power imbalances. DG output, survivability index, and node distance from substation are chosen as input to Sugeno type fuzzy logic controller. The stochastic performance of proposed fuzzy expert systems was evaluated on a modified IEEE 37 node test feeder with 15 minutes characteristics time interval varying static ZIP load models.

  13. An Acceleration Slip Regulation Strategy for Four-Wheel Drive Electric Vehicles Based on Sliding Mode Control

    Directory of Open Access Journals (Sweden)

    Hongwen He

    2014-06-01

    Full Text Available This paper presents an acceleration slip regulation (ASR system for four-wheel drive (4WD electric vehicles, which are driven by the front and rear axles simultaneously. The ASR control strategy includes three control modes: average distribution of inter-axle torque, optimal distribution of inter-axle torque and independent control of optimal slip rate, respectively, which are designed based on the torque adaptive principle of inter-axle differential and sliding mode control theory. Furthermore, in order to accurately describe the longitudinal tyre force characteristic, a slip rate calculation formula in the form of a state equation was used for solving the numerical problem posed by the traditional way. A simulation was carried out with the MATLAB/Simulink software. The simulation results show that the proposed ASR system can fully use the road friction condition, inhibit the drive-wheels from slipping, and improve the vehicle longitudinal driving stability.

  14. A New Approach for Preventive/Corrective Control Strategy to Avoid Voltage Collapse Based on FACTS Devices Investment

    Science.gov (United States)

    El-Araby, E. E.; Yorino, Naoto; Sasaki, Hiroshi

    This paper proposes a new method of optimal FACTS devices allocation to be used in the preventive/corrective control (PCC) against voltage collapse. The new formulation takes into consideration the transition states that the power system may expose such as normal state and contingency states. For the severe contingencies that drive the system to voltage collapse, the corrective control is initiated by means of fast response of FACTS and load shedding to restore the system with small positive load margin, then the preventive control is carried out using all the fast and slow devices ensuring security margin and voltage feasibility. For this control strategy, FACTS allocation are determined based on the minimum cost for the installations and the operations.. The problem is formulated as a mixed integer nonlinear programming problem, which is solved using hybrid genetic algorithm/successive liner programming (GA/SLP) approach. The IEEE 57 bus system is tested to demonstrate the effectiveness of the proposed method.

  15. Optimal Control Strategy for Marine Ssp Podded Propulsion Motor Based on Strong Tracking-Epf

    Directory of Open Access Journals (Sweden)

    Yao Wenlong

    2015-09-01

    Full Text Available Aiming at the non-linearity of state equation and observation equation of SSP (Siemen Schottel Propulsor propulsion motor, an improved particle filter algorithm based on strong tracking extent Kalman filter (ST-EKF was presented, and it was imported into the marine SSP propulsion motor control system. The strong tracking filter was used to update particles in the new algorithm and produce importance densities. As a result, the problems of particle degeneracy and sample impoverishment were ameliorated, the propulsion motor states and the rotor resistance were estimated simultaneously using strong track filter (STF, and the tracking ability of marine SSP propulsion motor control system was improved. Simulation result shown that the improved EPF algorithm was not only improving the prediction accuracy of the motor states and the rotor resistance, but also it can satisfy the requirement of navigation in harbor. It had the better accuracy than EPF algorithm.

  16. Comparative Studies of Different Control Strategies of a Dynamic Voltage Restorer Based on Matrix Converter

    Directory of Open Access Journals (Sweden)

    Amin Shabanpour

    2012-01-01

    Full Text Available A dynamic voltage restorer (DVR with no energy storage is studied. By using a matrix converter instead of the conventional AC/DC/AC converters, elimination of the DC-link capacitor is possible. The switching algorithm of matrix converter is the space vector modulation. There are different compensation algorithms to control the conventional DVR. These methods have been analyzed in this paper for the proposed matrix-converter-based DVR. A deep analysis through different diagrams would show the advantages or disadvantages of each compensation method. Equations for all methods are derived, and the characteristics of algorithms are compared with each other.

  17. Automation infrastructure and operation control strategy in a stand-alone power system based on renewable energy sources

    Science.gov (United States)

    Ziogou, Chrysovalantou; Ipsakis, Dimitris; Elmasides, Costas; Stergiopoulos, Fotis; Papadopoulou, Simira; Seferlis, Panos; Voutetakis, Spyros

    The design of the automation system and the implemented operation control strategy in a stand-alone power system in Greece are fully analyzed in the present study. A photovoltaic array and three wind generators serve as the system main power sources and meet a predefined load demand. A lead-acid accumulator is used to compensate the inherent power fluctuations (excess or shortage) and to regulate the overall system operation, based on a developed power management strategy. Hydrogen is produced by using system excess power in a proton exchange membrane (PEM) electrolyzer and is further stored in pressurized cylinders for subsequent use in a PEM fuel cell in cases of power shortage. A diesel generator complements the integrated system and is employed only in emergency cases, such as subsystems failure. The performance of the automatic control system is evaluated through the real-time operation of the power system where data from the various subsystems are recorded and analyzed using a supervised data acquisition unit. Various network protocols were used to integrate the system devices into one central control system managing in this way to compensate for the differences between chemical and electrical subunits. One of the main advantages is the ability of process monitoring from distance where users can perform changes to system principal variables. Furthermore, the performance of the implemented power management strategy is evaluated through simulated scenarios by including a case study analysis on system abilities to meet higher than expected electrical load demands.

  18. New Strategy for Congestion Control based on Dynamic Adjustment of Congestion Window

    Directory of Open Access Journals (Sweden)

    Gamal Attiya

    2012-03-01

    Full Text Available This paper presents a new mechanism for the end-to-end congestion control, called EnewReno. The proposed mechanism is based on the enhancement of both the congestion avoidance and the fast recovery algorithms of the TCP NewReno so as to improve its performance. The basic idea of the proposed mechanism is to adjust the congestion window of the TCP sender dynamically based on the level of congestion in the network so as to allow transferring more packets to the destination. The performance of the proposed mechanism is evaluated and compared with the most recent mechanisms by simulation studies using the well known Network Simulator NS-2 and the realistic topology generator GT-ITM.

  19. Quantum representation and watermark strategy for color images based on the controlled rotation of qubits

    Science.gov (United States)

    Li, Panchi; Xiao, Hong; Li, Binxu

    2016-11-01

    In this paper, a novel quantum representation and watermarking scheme based on the controlled rotation of qubits are proposed. Firstly, a flexible representation for quantum color image (FRQCI) is proposed to facilitate the image processing tasks. Some basic image processing operations based on FRQCI representation are introduced. Then, a novel watermarking scheme for quantum images is presented. In our scheme, the carrier image is stored in the phase θ of a qubit; at the same time, the watermark image is embedded into the phase φ of a qubit, which will not affect the carrier image's visual effect. Before being embedded into the carrier image, the watermark image is scrambled to be seemingly meaningless using quantum circuits, which further ensures the security of the watermark image. All the operations mentioned above are implemented by the controlled rotation of qubits. The experimental results on the classical computer show that the proposed watermarking scheme has better visual quality under a higher embedding capacity and outperforms the existing schemes in the literature.

  20. Quantum representation and watermark strategy for color images based on the controlled rotation of qubits

    Science.gov (United States)

    Li, Panchi; Xiao, Hong; Li, Binxu

    2016-08-01

    In this paper, a novel quantum representation and watermarking scheme based on the controlled rotation of qubits are proposed. Firstly, a flexible representation for quantum color image (FRQCI) is proposed to facilitate the image processing tasks. Some basic image processing operations based on FRQCI representation are introduced. Then, a novel watermarking scheme for quantum images is presented. In our scheme, the carrier image is stored in the phase θ of a qubit; at the same time, the watermark image is embedded into the phase φ of a qubit, which will not affect the carrier image's visual effect. Before being embedded into the carrier image, the watermark image is scrambled to be seemingly meaningless using quantum circuits, which further ensures the security of the watermark image. All the operations mentioned above are implemented by the controlled rotation of qubits. The experimental results on the classical computer show that the proposed watermarking scheme has better visual quality under a higher embedding capacity and outperforms the existing schemes in the literature.

  1. A Dynamic Control Strategy for Hybrid Electric Vehicles Based on Parameter Optimization for Multiple Driving Cycles and Driving Pattern Recognition

    Directory of Open Access Journals (Sweden)

    Zhenzhen Lei

    2017-01-01

    Full Text Available The driving pattern has an important influence on the parameter optimization of the energy management strategy (EMS for hybrid electric vehicles (HEVs. A new algorithm using simulated annealing particle swarm optimization (SA-PSO is proposed for parameter optimization of both the power system and control strategy of HEVs based on multiple driving cycles in order to realize the minimum fuel consumption without impairing the dynamic performance. Furthermore, taking the unknown of the actual driving cycle into consideration, an optimization method of the dynamic EMS based on driving pattern recognition is proposed in this paper. The simulation verifications for the optimized EMS based on multiple driving cycles and driving pattern recognition are carried out using Matlab/Simulink platform. The results show that compared with the original EMS, the former strategy reduces the fuel consumption by 4.36% and the latter one reduces the fuel consumption by 11.68%. A road test on the prototype vehicle is conducted and the effectiveness of the proposed EMS is validated by the test data.

  2. Energy optimal control strategies for electro motors; low-cost and sensorless PWM-VSI based induction motor control. Vol. 1: Main report, appendix and annex

    Energy Technology Data Exchange (ETDEWEB)

    Abrahamsen, F.

    1998-02-01

    When variable speed induction motor drives are used in applications that run at low load for long periods, energy can be saved by reducing the motor flux at low load. In this report the efficiency of 2.2 kW standard and high-efficiency motor drives are investigated experimentally with efficiency optimized and constant flux control, with sinusoidal and PWM voltage supply and with varying switching frequency. Steady-state motor models are developed and verified experimentally, and are used to analyze and develop efficiency optimizing control strategies. Four energy optimal control strategies are tested experimentally: cos({phi}) control, model-based control, off-line calculated airgap flux control and stator current/input power minimising search control. Their dynamical properties and their ability to reject load disturbances are analysed. Their ability to save energy is tested on a water pump system. For a typical predefined test-cycle the energy optimal control reduces the energy consumption with 10% compared with classical constant V/Hz control. (au)

  3. Strategies For Malaria Control In Mangalore City

    OpenAIRE

    Kiran Udaya .N

    1999-01-01

    Research questions: What different strategies should be used to effectively control problem of malaria? Objectives: 1) To study the problem of malaria. 2) To study different strategies for effective control of malaria. Study design: Observational and record based. The problem of malaria was studied for three years from 1996-1998 Participants: Individuals having fever. Setting: Community based in Mangalore City. Study variables: Fever cases, blood slides prepared, slides found positive, agency...

  4. Mobile Target Tracking Based on Hybrid Open-Loop Monocular Vision Motion Control Strategy

    Directory of Open Access Journals (Sweden)

    Cao Yuan

    2015-01-01

    Full Text Available This paper proposes a new real-time target tracking method based on the open-loop monocular vision motion control. It uses the particle filter technique to predict the moving target’s position in an image. Due to the properties of the particle filter, the method can effectively master the motion behaviors of the linear and nonlinear. In addition, the method uses the simple mathematical operation to transfer the image information in the mobile target to its real coordinate information. Therefore, it requires few operating resources. Moreover, the method adopts the monocular vision approach, which is a single camera, to achieve its objective by using few hardware resources. Firstly, the method evaluates the next time’s position and size of the target in an image. Later, the real position of the objective corresponding to the obtained information is predicted. At last, the mobile robot should be controlled in the center of the camera’s vision. The paper conducts the tracking test to the L-type and the S-type and compares with the Kalman filtering method. The experimental results show that the method achieves a better tracking effect in the L-shape experiment, and its effect is superior to the Kalman filter technique in the L-type or S-type tracking experiment.

  5. 基于支持向量机逼近的内模控制系统及应用%SVM Approximate-based Internal Model Control Strategy

    Institute of Scientific and Technical Information of China (English)

    王耀南; 袁小芳

    2008-01-01

    A support vector machine (SVM) approximate-based internal model control (IMC) strategy is presented for the steam valving control of synchronous generators. The proposed SVM IMC strategy includes two main parts: SVM approximate inverse controller and uncertainty compensation in the internal model structure. The SVM inverse controller is derived directly using an input-output approximation approach via Taylor expansion, and it is implemented through nonlinear system identification without further online training. Frthermore, a robustness filter is used for uncertainty compensation in the internal model structure.Simulations show the effectiveness of the SVM IMC strategy for the steam valving control.

  6. Systems and methods for providing power to a load based upon a control strategy

    Science.gov (United States)

    Perisic, Milun; Kajouke, Lateef A; Ransom, Ray M

    2013-12-24

    Systems and methods are provided for an electrical system. The electrical system includes a load, an interface configured to receive a voltage from a voltage source, and a controller configured to receive the voltage from the voltage source through the interface and to provide a voltage and current to the load. Wherein, when the controller is in a constant voltage mode, the controller provides a constant voltage to the load, when the controller is in a constant current mode, the controller provides a constant current to the load, and when the controller is in a constant power mode, the controller provides a constant power to the load.

  7. Optimizing insecticide allocation strategies based on houses and livestock shelters for visceral leishmaniasis control in Bihar, India.

    Science.gov (United States)

    Gorahava, Kaushik K; Rosenberger, Jay M; Mubayi, Anuj

    2015-07-01

    Visceral leishmaniasis (VL) is the most deadly form of the leishmaniasis family of diseases, which affects numerous developing countries. The Indian state of Bihar has the highest prevalence and mortality rate of VL in the world. Insecticide spraying is believed to be an effective vector control program for controlling the spread of VL in Bihar; however, it is expensive and less effective if not implemented systematically. This study develops and analyzes a novel optimization model for VL control in Bihar that identifies an optimal (best possible) allocation of chosen insecticide (dichlorodiphenyltrichloroethane [DDT] or deltamethrin) based on the sizes of human and cattle populations in the region. The model maximizes the insecticide-induced sandfly death rate in human and cattle dwellings while staying within the current state budget for VL vector control efforts. The model results suggest that deltamethrin might not be a good replacement for DDT because the insecticide-induced sandfly deaths are 3.72 times more in case of DDT even after 90 days post spray. Different insecticide allocation strategies between the two types of sites (houses and cattle sheds) are suggested based on the state VL-control budget and have a direct implication on VL elimination efforts in a resource-limited region.

  8. Strategies for Industrial Multivariable Control

    DEFF Research Database (Denmark)

    Hangstrup, M.

    dynamics and gains strongly depend upon one or more physical parameters characterizing the operating point. This class covers many industrial systems such as airplanes, ships, robots and process control systems. Power plant boilers are representatives for process control systems in general. The dynamics......Multivariable control strategies well-suited for industrial applications are suggested. The strategies combine the practical advantages of conventional SISO control schemes and -technology with the potential of multivariable controllers. Special emphasis is put on parameter-varying systems whose...... and gains of power plant boilers strongly depend upon the load (instantaneous power production). This non-linear behavior suggests the use of gain-scheduling. For parameter-varying systems the multivariable control strategies can hence be divided into the following subsequent steps: choice of architecture...

  9. A Moving Control Strategy Based on RSSI Real-time Localization in Multi-tier Mobile Sensor Networks

    Directory of Open Access Journals (Sweden)

    Jian Wen

    2009-12-01

    Full Text Available Research on communication collection pattern for traditional fixed nodes with some mobile ones has been already extensive. However, almost nothing is done in tiered movement policy while movement track is unknown and sensor nodes drift at random direction. To fit the development of “smart dust” wireless sensor network, a new moving control strategy based on RSSI real-time localization is proposed in the multi-tier mobile sensor networks. First, we divide the monitoring field into several sub-regions so that fusion nodes can collect data in their own parts respectively, and use constraints-based mobile localization (CML algorithm to calculate the location information of each sensor node. Then, a new Maximum Likelihood Nearest Neighbor (MLNN algorithm is proposed to design optimal routes for fusion nodes. Finally, each fusion node can collect sensed data along this route. Simulation results show that the moving control strategy can provide a good solution of the problem on tiered mobile network of instable communication and high-fraction of event loss. Only layouting a small number of fusion nodes, the network can receive higher data success rate and lower data transmission delay, and is very suitable for the large-scale industry real-time monitoring application of wireless sensor networks.

  10. Learning an intermittent control strategy for postural balancing using an EMG-based human-computer interface.

    Science.gov (United States)

    Asai, Yoshiyuki; Tateyama, Shota; Nomura, Taishin

    2013-01-01

    It has been considered that the brain stabilizes unstable body dynamics by regulating co-activation levels of antagonist muscles. Here we critically reexamined this established theory of impedance control in a postural balancing task using a novel EMG-based human-computer interface, in which subjects were asked to balance a virtual inverted pendulum using visual feedback information on the pendulum's position. The pendulum was actuated by a pair of antagonist joint torques determined in real-time by activations of the corresponding pair of antagonist ankle muscles of subjects standing upright. This motor-task raises a frustrated environment; a large feedback time delay in the sensorimotor loop, as a source of instability, might favor adopting the non-reactive, preprogrammed impedance control, but the ankle muscles are relatively hard to co-activate, which hinders subjects from adopting the impedance control. This study aimed at discovering how experimental subjects resolved this frustrated environment through motor learning. One third of subjects adapted to the balancing task in a way of the impedance-like control. It was remarkable, however, that the majority of subjects did not adopt the impedance control. Instead, they acquired a smart and energetically efficient strategy, in which two muscles were inactivated simultaneously at a sequence of optimal timings, leading to intermittent appearance of periods of time during which the pendulum was not actively actuated. Characterizations of muscle inactivations and the pendulum¡Çs sway showed that the strategy adopted by those subjects was a type of intermittent control that utilizes a stable manifold of saddle-type unstable upright equilibrium that appeared in the state space of the pendulum when the active actuation was turned off.

  11. Learning an intermittent control strategy for postural balancing using an EMG-based human-computer interface.

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Asai

    Full Text Available It has been considered that the brain stabilizes unstable body dynamics by regulating co-activation levels of antagonist muscles. Here we critically reexamined this established theory of impedance control in a postural balancing task using a novel EMG-based human-computer interface, in which subjects were asked to balance a virtual inverted pendulum using visual feedback information on the pendulum's position. The pendulum was actuated by a pair of antagonist joint torques determined in real-time by activations of the corresponding pair of antagonist ankle muscles of subjects standing upright. This motor-task raises a frustrated environment; a large feedback time delay in the sensorimotor loop, as a source of instability, might favor adopting the non-reactive, preprogrammed impedance control, but the ankle muscles are relatively hard to co-activate, which hinders subjects from adopting the impedance control. This study aimed at discovering how experimental subjects resolved this frustrated environment through motor learning. One third of subjects adapted to the balancing task in a way of the impedance-like control. It was remarkable, however, that the majority of subjects did not adopt the impedance control. Instead, they acquired a smart and energetically efficient strategy, in which two muscles were inactivated simultaneously at a sequence of optimal timings, leading to intermittent appearance of periods of time during which the pendulum was not actively actuated. Characterizations of muscle inactivations and the pendulum¡Çs sway showed that the strategy adopted by those subjects was a type of intermittent control that utilizes a stable manifold of saddle-type unstable upright equilibrium that appeared in the state space of the pendulum when the active actuation was turned off.

  12. Preprocessing and Quality Control Strategies for Illumina DASL Assay-Based Brain Gene Expression Studies with Semi-Degraded Samples.

    Science.gov (United States)

    Chow, Maggie L; Winn, Mary E; Li, Hai-Ri; April, Craig; Wynshaw-Boris, Anthony; Fan, Jian-Bing; Fu, Xiang-Dong; Courchesne, Eric; Schork, Nicholas J

    2012-01-01

    Available statistical preprocessing or quality control analysis tools for gene expression microarray datasets are known to greatly affect downstream data analysis, especially when degraded samples, unique tissue samples, or novel expression assays are used. It is therefore important to assess the validity and impact of the assumptions built in to preprocessing schemes for a dataset. We developed and assessed a data preprocessing strategy for use with the Illumina DASL-based gene expression assay with partially degraded postmortem prefrontal cortex samples. The samples were obtained from individuals with autism as part of an investigation of the pathogenic factors contributing to autism. Using statistical analysis methods and metrics such as those associated with multivariate distance matrix regression and mean inter-array correlation, we developed a DASL-based assay gene expression preprocessing pipeline to accommodate and detect problems with microarray-based gene expression values obtained with degraded brain samples. Key steps in the pipeline included outlier exclusion, data transformation and normalization, and batch effect and covariate corrections. Our goal was to produce a clean dataset for subsequent downstream differential expression analysis. We ultimately settled on available transformation and normalization algorithms in the R/Bioconductor package lumi based on an assessment of their use in various combinations. A log2-transformed, quantile-normalized, and batch and seizure-corrected procedure was likely the most appropriate for our data. We empirically tested different components of our proposed preprocessing strategy and believe that our results suggest that a preprocessing strategy that effectively identifies outliers, normalizes the data, and corrects for batch effects can be applied to all studies, even those pursued with degraded samples.

  13. Fast control strategy for stabilising fixed-speed induction-generator-based wind turbines in an islanded distributed system

    DEFF Research Database (Denmark)

    Wei, Mu; Chen, Zhe

    2013-01-01

    wind generator cutting off. This study investigates and analyses the dynamic characteristics of an FSWT to reveal the behaviours of an FSWT under disturbances. Then a fast control strategy for stabilising an islanded DGS is proposed. The main contributions of the control strategy are: the total amount...... of reactive power compensation and load shedding may be determined precisely; all the operation execution points may be decided accurately to improve DGS stability. Furthermore, the implementation of the fast control strategy is also discussed. A case study is presented to demonstrate the effectiveness...

  14. Comparing strategies for controlling an African pest rodent: an empirically based theoretical study

    DEFF Research Database (Denmark)

    Stenseth, Nils Chr.; Leirs, Herwig; Mercelis, Saskia

    2001-01-01

    . This model incorporated three functional age categories (juveniles, subadults and adults) of both sexes and used density-dependent and density-independent factors, the latter represented by rainfall.3. The model was used to analyse the effect of rodent control on the population dynamics and resulting number...... of rats. Control measures affecting survival as well as reproduction were considered.4. The model showed that control measures reducing survival will only have long-term effects on population size if they are also applied when rodent densities are low. Control measures applied only when rodent densities...... are high will not have persistent effects, even at high mortality rates.5. The model demonstrated that control measures reducing reproduction are likely to prevent Mastomys outbreaks, but will keep densities low over a long period only when the contraceptive effect is strong (> 75% reduction).6. Provided...

  15. A Rule-Based Energy Management Strategy for a Plug-in Hybrid School Bus Based on a Controller Area Network Bus

    Directory of Open Access Journals (Sweden)

    Jiankun Peng

    2015-06-01

    Full Text Available This paper presents a rule-based energy management strategy for a plug-in hybrid school bus (PHSB. In order to verify the effectiveness and rationality of the proposed energy management strategy, the powertrain and control models were built with MATLAB/Simulink. The PHSB powertrain model includes an engine model, ISG (integrated started and generator model, drive motor model, power battery packs model, driver model, and vehicle longitudinal dynamics model. To evaluate the controller area network (CAN bus performance features such as the bus load, signal hysteresis, and to verify the reliability and real-time performance of the CAN bus multi-node control method, a co-simulation platform was built with CANoe and MATLAB/Simulink. The co-simulation results show that the control strategy can meet the requirements of the PHSB’s dynamic performance. Meanwhile, the charge-depleting mode (CD and charge-sustaining mode (CS can switch between each other and maintain a state-of-charge (SoC of around 30%, indicating that the energy management strategy effectively extends the working period of the CD mode and improves the fuel economy further. The energy consumption per 100 km includes 13.7 L diesel and 10.5 kW·h electricity with an initial SoC of 75%. The CANoe simulation results show that the bus communication performs well without error frames.

  16. THROTTLE CONTROL STRATEGIES IN THE PROCESS OF INTEGRATED POWERTRAIN CONTROL

    Institute of Scientific and Technical Information of China (English)

    Lei Yulong; Gao Bingzhao; Tian Hua; Ge Anlin; Yan Su

    2005-01-01

    Combining with the development of automated manual transmission (AMT), the various throttle control demands are analyzed under different working conditions of AMT such as tracking acceleration pedal, start, shift and so on. Based on simulation, the responding throttle control strategies are proposed, and a simple but effective throttle control method is presented. The testing results have proved that the strategies are effective for improving the pedal tracking precision and the qualities of start and shift.

  17. T-S Fuzzy Model Based Control Strategy for the Networked Suspension Control System of Maglev Train

    OpenAIRE

    2015-01-01

    The control problem for the networked suspension control system of maglev train with random induced time delay and packet dropouts is investigated. First, Takagi-Sugeno (T-S) fuzzy models are utilized to represent the discrete-time nonlinear networked suspension control system, and the parameters uncertainties of the nonlinear model have also been taken into account. The controllers take the form of parallel distributed compensation. Then, a sufficient condition for the stability of the netwo...

  18. Dendrimer-Based Selective Proteostasis-Inhibition Strategy to Control NSCLC Growth and Progression.

    Directory of Open Access Journals (Sweden)

    Kyla Walworth

    Full Text Available Elevated valosin containing protein (VCP/p97 levels promote the progression of non-small cell lung carcinoma (NSCLC. Although many VCP inhibitors are available, most of these therapeutic compounds have low specificity for targeted tumor cell delivery. Hence, the primary aim of this study was to evaluate the in vitro efficacy of dendrimer-encapsulated potent VCP-inhibitor drug in controlling non-small cell lung carcinoma (NSCLC progression. The VCP inhibitor(s (either in their pure form or encapsulated in generation-4 PAMAM-dendrimer with hydroxyl surface were tested for their in vitro efficacy in modulating H1299 (NSCLC cells proliferation, migration, invasion, apoptosis and cell cycle progression. Our results show that VCP inhibition by DBeQ was significantly more potent than NMS-873 as evident by decreased cell proliferation (p<0.0001, MTT-assay and migration (p<0.05; scratch-assay, and increased apoptosis (p<0.05; caspase-3/7-assay as compared to untreated control cells. Next, we found that dendrimer-encapsulated DBeQ (DDNDBeQ treatment increased ubiquitinated-protein accumulation in soluble protein-fraction (immunoblotting of H1299 cells as compared to DDN-control, implying the effectiveness of DBeQ in proteostasis-inhibition. We verified by immunostaining that DDNDBeQ treatment increases accumulation of ubiquitinated-proteins that co-localizes with an ER-marker, KDEL. We observed that proteostasis-inhibition with DDNDBeQ, significantly decreased cell migration rate (scratch-assay and transwell-invasion as compared to the control-DDN treatment (p<0.05. Moreover, DDNDBeQ treatment showed a significant decrease in cell proliferation (p<0.01, MTT-assay and increased caspase-3/7 mediated apoptotic cell death (p<0.05 as compared to DDN-control. This was further verified by cell cycle analysis (propidium-iodide-staining that demonstrated significant cell cycle arrest in the G2/M-phase (p<0.001 by DDNDBeQ treatment as compared to control

  19. Dendrimer-Based Selective Proteostasis-Inhibition Strategy to Control NSCLC Growth and Progression

    Science.gov (United States)

    Walworth, Kyla; Bodas, Manish; Campbell, Ryan John; Swanson, Doug; Sharma, Ajit; Vij, Neeraj

    2016-01-01

    Elevated valosin containing protein (VCP/p97) levels promote the progression of non-small cell lung carcinoma (NSCLC). Although many VCP inhibitors are available, most of these therapeutic compounds have low specificity for targeted tumor cell delivery. Hence, the primary aim of this study was to evaluate the in vitro efficacy of dendrimer-encapsulated potent VCP-inhibitor drug in controlling non-small cell lung carcinoma (NSCLC) progression. The VCP inhibitor(s) (either in their pure form or encapsulated in generation-4 PAMAM-dendrimer with hydroxyl surface) were tested for their in vitro efficacy in modulating H1299 (NSCLC cells) proliferation, migration, invasion, apoptosis and cell cycle progression. Our results show that VCP inhibition by DBeQ was significantly more potent than NMS-873 as evident by decreased cell proliferation (p<0.0001, MTT-assay) and migration (p<0.05; scratch-assay), and increased apoptosis (p<0.05; caspase-3/7-assay) as compared to untreated control cells. Next, we found that dendrimer-encapsulated DBeQ (DDNDBeQ) treatment increased ubiquitinated-protein accumulation in soluble protein-fraction (immunoblotting) of H1299 cells as compared to DDN-control, implying the effectiveness of DBeQ in proteostasis-inhibition. We verified by immunostaining that DDNDBeQ treatment increases accumulation of ubiquitinated-proteins that co-localizes with an ER-marker, KDEL. We observed that proteostasis-inhibition with DDNDBeQ, significantly decreased cell migration rate (scratch-assay and transwell-invasion) as compared to the control-DDN treatment (p<0.05). Moreover, DDNDBeQ treatment showed a significant decrease in cell proliferation (p<0.01, MTT-assay) and increased caspase-3/7 mediated apoptotic cell death (p<0.05) as compared to DDN-control. This was further verified by cell cycle analysis (propidium-iodide-staining) that demonstrated significant cell cycle arrest in the G2/M-phase (p<0.001) by DDNDBeQ treatment as compared to control-DDN. Moreover

  20. Systems and methods for providing power to a load based upon a control strategy

    Energy Technology Data Exchange (ETDEWEB)

    Perisic, Milun; Lawrence, Christopher P; Ransom, Ray M; Kajouke, Lateef A

    2014-11-04

    Systems and methods are provided for an electrical system. The electrical system, for example, includes a first load, an interface configured to receive a voltage from a voltage source, and a controller configured to receive the voltage through the interface and to provide a voltage and current to the first load. The controller may be further configured to, receive information on a second load electrically connected to the voltage source, determine an amount of reactive current to return to the voltage source such that a current drawn by the electrical system and the second load from the voltage source is substantially real, and provide the determined reactive current to the voltage source.

  1. Active Power Quality Improvement Strategy for Grid-connected Microgrid Based on Hierarchical Control

    DEFF Research Database (Denmark)

    Wei, Feng; Sun, Kai; Guan, Yajuan

    2017-01-01

    When connected to a distorted grid utility, droop-controlled grid-connected microgrids (DCGC-MG) exhibit low equivalent impedance. The harmonic and unbalanced voltage at the point of common coupling (PCC) deteriorates the power quality of the grid-connected current (GCC) of DCGC-MG. This work...

  2. Implementing two DC motor speed control strategies

    Directory of Open Access Journals (Sweden)

    José Danilo Rairán Antolines

    2010-05-01

    Full Text Available While linear control techniques for dynamic systems have been widely tested, systems are not linear in practice. This means that controllers must be re-tuned to make them useful in an experimental setup. This article presents the tuning and re-tuning process for two control strategies: a PID and an algorithm based on the choice of overall transfer function controlling a DC permanent magnet motor. The algorithms’ performance is evaluated and some recommendations are made.

  3. Current Control Strategy of Chain Circuit STATCOM

    Institute of Scientific and Technical Information of China (English)

    WANG Xuan; FU Jian; TENG Letian; SUN Lijing; ZHAO Ruibin; WU Shouyuan; DENG Zhanfeng

    2012-01-01

    In order to study the current control strategy based on the chain circuit static synchronous compensator (STATCOM) dynamic model and the design control system with good stability and tracking accuracy, this paper applies the chain circuit STATCOM small signal AC model, and proposes the following assumptions:

  4. Damping control strategies of inter-area low-frequency oscillation for DFIG-based wind farms integrated into a power system

    DEFF Research Database (Denmark)

    Li, Hui; Liu, Shengquan; Ji, Haiting

    2014-01-01

    on the power system stabilizer (PSS) control method. Transient simulation on different damping gain coefficients are conducted for justification. Following the OTEF mechanism analysis, an additional fuzzy damping control strategy with the active/reactive power loop is proposed by identifying the oscillation......This study investigates the inter-area low-frequency damping control strategies of a doubly fed induction generator (DFIG)-based wind farm through oscillation transient energy function (OTEF) analysis. Based on the OTEF descent expressions, the feasibility of damping the inter-area low...... phase and the severity to prevent different damping gain coefficients from affecting the presented PSS damping control method. Transient and dynamic simulation results and comparisons showed that both additional control strategies with the active and reactive power loops of the DFIG-based wind farm can...

  5. Propose the controlling strategy of wheeled mobile robot based on the consciousness

    Science.gov (United States)

    Emaru, Takanori; Tanaka, Kazuo; Tsuchiya, Takeshi

    2005-12-01

    We have proposed a new approach to utilize the infinitesimal reflected waves by integrating the reflected waves. This method enables robot to move in unknown environments as it controls its speed smoothly. It is implemented using a transducer with a scanning system, and has a great ability of obtaining the traversable area for a robot in unknown environments in which the distance cannot be precisely measured. The proposed system, termed the integration-type ultrasonic wave sensor system, has following arbitrary parameters that the system designer can determine: sampling time of sonar, sampling time of scanning, range of scanning, speed of scanning, and so on. It is very difficult to determine them appropriately in response to changing environments or tasks. In this paper, we try to determine the arbitrary parameters of the integration-type ultrasonic wave sensor system on the basis of the 'consciousness'. We have proposed the speed control or obstacle avoidance by using the integration-type ultrasonic wave sensor system, and we define it as the unconsciousness movements. On the other hand, higher-level tasks such as navigation or map building are defined as the consciousness movements. The purpose of our research is to propose a simple construction and controlling method of the robot system by introducing the concept of consciousness. In preparation for this purpose, some experiments and discussion will be performed in this paper.

  6. Expected shortage based pre-release strategy for reservoir flood control

    Science.gov (United States)

    Chou, Frederick N.-F.; Wu, Chia-Wen

    2013-08-01

    In Taiwan, an increase in the frequency of severe flooding over the past decade has prompted demand for improved reservoir operation to control flood-related damage. Flood protection of reservoir can be enhanced by pre-releasing its storage to more adequately accommodate an impending flood. A procedure is proposed in this paper to evaluate the impact of pre-releases of flood control operation on water supply. A basic criterion used is that the pre-release of reservoir storage should not cause intolerable increment of water shortage risk. The shortage risks for different pre-release scenarios are simulated according to the uncertainties of storm rainfall and post-flood ordinary inflow till the end of next dry season. Two operational objectives are provided to help determining the target pre-released level. One of which identifies the minimum allowable pre-released threshold. The other seeks the pre-released level which maximizes the probability that the reservoir release during flood is below the non-damaging discharge and the end-of-operation storage target can still be achieved. This paper evaluated the operations of Tsengwen Reservoir of southern Taiwan during four typhoons from 2007 to 2012 to illustrate the significant contribution of pre-releases in reducing downstream flood potential.

  7. Improved Droop Control Strategy for Grid-Connected Inverters

    DEFF Research Database (Denmark)

    Abusara, Mohammad; Sharkh, Suleiman; Guerrero, Josep M.

    2015-01-01

    An improved control strategy for grid-connected inverters within microgrids is presented in this paper. The strategy is based on the classical P-ω and Q-V droop method. The improvement in the proposed control strategy is twofold: Firstly, the transient response of the droop controller is improved...... are presented to validate the model and demonstrate the controller capabilities....

  8. Comparison between Different Control Strategies of a Z-Source Inverter Based Dynamic Voltage Restorer

    Directory of Open Access Journals (Sweden)

    Abolfazl Kazemdehdashti

    2013-01-01

    Full Text Available In this paper, dynamic voltage restorer (DVR compensation methods are compared to each other for the load side connected shunt converter topology of z-source inverter based DVR to choose the best method. Four different topologies are recognized for DVR that two of them have energy storage devices, and two topologies have no energy storage that take ener\\-gy from the grid during the period of compensation. Here the load side connected shunt converter topology that takes necessary energy from the grid is used. Pre-sag compensation, in-phase compensation, energy-optimized methods are the three DVR compensation methods that studied and compared. A deep analysis through different diagrams would show the advantages or disadvantages of each compensation method. Equations for all methods are derived and the characteristics of algorithms are compared with each other. The simulation results done by SIMULINK/ MATLAB shows compensating by this topology based on the compensation methods.

  9. Risk-factors and strategies for control of carcinoma cervix in India: Hospital based cytological screening experience of 35 years

    Directory of Open Access Journals (Sweden)

    J S Misra

    2009-01-01

    Full Text Available Purpose: Role of risk factors in cervical carcinogenesis and strategies for control of the disease have been assessed from the accumulated cytological data, derived from 35 years of hospital-based screening in Lucknow, North India. Materials and Methods: A total of 36,484 women have been cytologically screened during a span of 35 years (April 1971 - June 2005 in the Gynaecology out patient department (OPD of Queen Mary′s Hospital. Results: The frequency of Squamous Intraepithelial Lesion (SIL and carcinoma was found to be 7.2% and 0.6%, respectively, in the present study. The study revealed high age and parity as a predominant factor in cervical carcinogenesis, while viral sexually transmitted disease (STDs -human papilloma virus (HPV and Herpes simplex virus (HSV were also largely associated with SIL cases. The study emphasized great value of clinically downstaging the cervical cancer by detecting cervical cancer in the early stage. The study also revealed a significant difference in the frequency of SIL in symptomatic and asymptomatic women. Conclusion: Based on the analyzed data, it was felt that single lifetime screening, which appears to be the most feasible and affordable mode for control of carcinoma cervix in developing countries like India, should be carried out in all women of high parity irrespective of age (with three or more children and in older women above the age of 40 years irrespective of parity.

  10. Wind Farm Active Power Dispatch for Output Power Maximizing Based on a Wind Turbine Control Strategy for Load Minimizing

    DEFF Research Database (Denmark)

    Zhang, Baohua; Hu, Weihao; Hou, Peng

    2015-01-01

    Inclusion of the wake effect in the wind farm control design (WF) can increase the total captured power by wind turbines (WTs), which is usually implemented by derating upwind WTs. However, derating the WT without a proper control strategy will increase the structural loads, caused by operation i...

  11. Invited review: Determinants of farmers' adoption of management-based strategies for infectious disease prevention and control.

    Science.gov (United States)

    Ritter, Caroline; Jansen, Jolanda; Roche, Steven; Kelton, David F; Adams, Cindy L; Orsel, Karin; Erskine, Ron J; Benedictus, Geart; Lam, Theo J G M; Barkema, Herman W

    2017-02-22

    The prevention and control of endemic pathogens within and between farms often depends on the adoption of best management practices. However, farmers regularly do not adopt recommended measures or do not enroll in voluntary disease control programs. This indicates that a more comprehensive understanding of the influences and extension tools that affect farmers' management decisions is necessary. Based on a review of relevant published literature, we developed recommendations to support policy-makers, industry representatives, researchers, veterinarians, and other stakeholders when motivating farmers to adopt best management practices, and to facilitate the development and implementation of voluntary prevention and control programs for livestock diseases. Farmers will make management decisions based on their unique circumstances, agricultural contexts, beliefs, and goals. Providing them with rational but universal arguments might not always be sufficient to motivate on-farm change. Implementation of recommended management practices is more likely if farmers acknowledge the existence of a problem and their responsibility to take action. The perceived feasibility and effectiveness of the recommended management strategy and sufficient technical knowledge further increase the likelihood of adequate adoption. Farmers will also weigh the expected advantages of a proposed change against the expected disadvantages, and these considerations often include internal drivers such as pride or the desire to conform with perceived standards. Extension tools and farmers' social referents (e.g., veterinarians, peers) not only provide technical information but also influence these standards. Whereas mass media have the potential to deliver information to a broad audience, more personal approaches such as participatory group learning or individual communication with farm advisors can enable the tailoring of recommendations to farmers' situations. Approaches that appeal to farmers

  12. SPARTINA CONTROL STRATEGY OF CHINA

    Institute of Scientific and Technical Information of China (English)

    TAN Fang-Lin

    2007-01-01

    Spartina is a kind of very important and invasive grass. In its native range, it is very important for erosion control, fish, wildlife, and estuary reclamation. Therefore, it was introduced to many countries. Since 1963, it was introduced to China. Up to now, it was intentionally or accidentally planted nearly all estuaries in the east coast of China and the area was estimated over 0.1 × 106 hm2. As other introduced plants, Spartina grows very vigorously in China,and this caused many environmental and economical problems. So, it is an emergency to develop a Spartina control strategy of China. In the paper, the history of Spartina introduction in China was reviewed, and several methods which were probably feasible for China to control Spartina were introduced, including physical/mechanical (such as mowing, digging, and dredging), chemical, and biological methods. Before taking any measurments to control Spartina, 2 things should be done. The first was to develop a plan and make an inventory; the second was to select a feasible method according to local climatic, economic, social, and ecological conditions. It was suggested that it would be very important to assess the possible effect of control methods on the environment in order to prevent from causing other environmental problems.KEY WORDS :Spartina; control method; control strategy; environmental assessment

  13. Research of IGPC Control Strategy Based-on Hybrid Optimization for Power Station Boiler Superheated Steam Temperature

    Directory of Open Access Journals (Sweden)

    Benxian Xiao

    2014-01-01

    Full Text Available Implicit Generalized Predictive Control (IGPC algorithm can directly identify controller parameters without the need of solving Diophantine equation, thus can reduce the on-line algorithm computation time. In order to improve IGPC performance and extend its application, modified Particle Swarm Optimization (PSO algorithm is introduced into IGPC rolling horizon optimization, combined with general IGPC gradient optimization method under unconstrained condition, a new hybrid optimization method is obtained, this modified IGPC can be used to both of the non-constraint industry process control and the constraint industry process control. Aiming at the superheated steam temperature control of sub-critical 600MW boiler, a new cascade compound control strategy that combines an outer loop IGPC master adjuster and an inner loop PID auxiliary adjuster is adopted. Finally the simulation results have shown that the proposed method can constrain the control action, prevent dramatic change of the input signal, thus can achieve good static and dynamic performances.

  14. Decentralized Coordinated Control Strategy of Islanded Microgrids

    DEFF Research Database (Denmark)

    Wu, Dan

    control strategies in this thesis, in order to promote the decentralization of the overall system. Especially the consensus algorithm based secondary level is investigated in the thesis in order to simplify the communication configuration which only flood information through the neighboring units...

  15. Longitudinal Control Strategy for Vehicle Adaptive Cruise Control Systems

    Institute of Scientific and Technical Information of China (English)

    WU Li-jun; LIU Zhao-du; MA Yue-feng

    2007-01-01

    A new longitudinal control strategy for vehicle adaptive cruise control (ACC) systems is presented.The running relationship between the ACC vehicle and the detected target vehicle is described by the relative velocity and the deviation between the actual headway distance and the prescribed safety distance.Based on this,two state space models are built and the linear quadratic optimal control theory is used to yield desired velocity for the ACC-equipped vehicle when with the target vehicle detected.By switching among four control modes,the desired velocity profile is designed to deal with different running situations.A velocity controller,which includes a PID controller for throttle openness and a neural network controller for brake application,is developed to achieve the desired velocity profile.The proposed control strategy is applied to a non-linear vehicle model in a simulation environment and is shown to provide the ACC vehicle comfortable ride and satisfying safety.

  16. A novel Q-based online model updating strategy and its application in statistical process control for rubber mixing

    Institute of Scientific and Technical Information of China (English)

    Chunying Zhang; Sun Chen; Fang Wu; Kai Song

    2015-01-01

    To overcome the large time-delay in measuring the hardness of mixed rubber, rheological parameters were used to predict the hardness. A novel Q-based model updating strategy was proposed as a universal platform to track time-varying properties. Using a few selected support samples to update the model, the strategy could dramat-ical y save the storage cost and overcome the adverse influence of low signal-to-noise ratio samples. Moreover, it could be applied to any statistical process monitoring system without drastic changes to them, which is practical for industrial practices. As examples, the Q-based strategy was integrated with three popular algorithms (partial least squares (PLS), recursive PLS (RPLS), and kernel PLS (KPLS)) to form novel regression ones, QPLS, QRPLS and QKPLS, respectively. The applications for predicting mixed rubber hardness on a large-scale tire plant in east China prove the theoretical considerations.

  17. A Novel Control Strategy of DFIG Based on the Optimization of Transfer Trajectory at Operation Points in the Islanded Power System

    Directory of Open Access Journals (Sweden)

    Zengqiang Mi

    2016-01-01

    Full Text Available A novel control strategy based on the optimization of transfer trajectory at operation points for DFIG is proposed. Aim of this control strategy is to reduce the mechanical fatigue of DFIG caused by the frequent adjustment of rotating speed and pitch angle when operating in the islanded power system. Firstly, the stability of DFIG at different operation points is analyzed. Then an optimization model of transfer trajectory at operation points is established, with the minimum synthetic adjustment amount of rotating speed and pitch angle as the objective function and with the balance of active power and the stability of operation points as the constraint conditions. Secondly, the wind speed estimator is designed, and the control strategy of pitch system is improved to cooperate with the indirect stator flux orientation control technology for rotor-side inverter control. Then by the coordination control of its rotating speed and pitch angle, an operation trajectory controller is established to ensure the islanded operation of DFIG along the optimal transfer trajectory. Finally, the simulation results show that the proposed control strategy is technical feasibility with good performance.

  18. Development of a fluid bed granulation process control strategy based on real-time process and product measurements.

    Science.gov (United States)

    Burggraeve, Anneleen; Silva, Ana F T; Van den Kerkhof, Tom; Hellings, Mario; Vervaet, Chris; Remon, Jean Paul; Vander Heyden, Yvan; De Beer, Thomas

    2012-10-15

    This article describes the results of three case studies conducted consecutively, in order to develop a process control strategy for a top-spray fluid bed granulation process. The use of several real-time particle size (i.e., spatial filter velocimetry and focused beam reflectance measurement) and moisture (i.e., near infrared (NIR) and Lighthouse near infrared spectroscopy) analyzers was examined. A feed-forward process control method was developed, where in-line collected granulation information during the process spraying phase was used to determine the optimum drying temperature of the consecutive drying phase. Via real-time monitoring of process (i.e., spraying temperature and spray rate) and product (i.e., granule size distribution and moisture) parameters during the spraying period, the batch bulk density was predicted at the end of the spraying cycle, using a PLS model. When this predicted bulk density was not meeting the desired value, the developed control method allowed the calculation of an adjusted drying temperature leading to the desired batch bulk density at the end of the granulation process. Besides the development of the feed-forward control strategy, a quantitative PLS model for in-line moisture content prediction of the granulated end product was built using the NIR data.

  19. Compound control strategy used in Electro-Mechanical Actuator (EMA)

    Science.gov (United States)

    Fu, Yongling; Yan, Meng

    2017-01-01

    This article briefly describes the overall structure of the loading test rig; establish mathematical model of loading EMA, analyze its stability, surplus force and other properties in MATLAB; propose a compound control strategy combined speed feedback, PID and feed-forward compensation based on structure invariance principle. To verify the effectiveness of the control strategy, do a co-simulation by designing a controller based on the control strategy above in MATLAB and building the EMA model in AMESim. The results show that the compound control strategy can significantly improve dynamic tracking accuracy and reduce surplus force.

  20. Impact of combined vector-control and vaccination strategies on transmission dynamics of dengue fever: a model-based analysis.

    Science.gov (United States)

    Knerer, Gerhart; Currie, Christine S M; Brailsford, Sally C

    2015-06-01

    Dengue fever is a vector-borne disease prevalent in tropical and subtropical regions. It is an important public health problem with a considerable and often under-valued disease burden in terms of frequency, cost and quality-of-life. Recent literature reviews have documented the development of mathematical models of dengue fever both to identify important characteristics for future model development as well as to assess the impact of dengue control interventions. Such reviews highlight the importance of short-term cross-protection; antibody-dependent enhancement; and seasonality (in terms of both favourable and unfavourable conditions for mosquitoes). The compartmental model extends work by Bartley (2002) and combines the following factors: seasonality, age-structure, consecutive infection by all four serotypes, cross-protection and immune enhancement, as well as combined vector-host transmission. The model is used to represent dengue transmission dynamics using parameters appropriate for Thailand and to assess the potential impact of combined vector-control and vaccination strategies including routine and catch-up vaccination strategies on disease dynamics. When seasonality and temporary cross-protection between serotypes are included, the model is able to approximate the observed incidence of dengue fever in Thailand. We find vaccination to be the most effective single intervention, albeit with imperfect efficacy (30.2 %) and limited duration of protection. However, in combination, control interventions and vaccination exhibit a marked impact on dengue fever transmission. This study shows that an imperfect vaccine can be a useful weapon in reducing disease spread within the community, although it will be most effective when promoted as one of several strategies for combating dengue fever transmission.

  1. Intelligence Based Fusion Control Strategy for Complex Vulcanizing Process%复杂硫化过程的智能融合控制策略

    Institute of Scientific and Technical Information of China (English)

    裴玉玲

    2013-01-01

    针对硫化过程中因模糊性与不确定性导致的塑胶产品成形过程难以控制、产品质量稳定性差的问题,提出了一种智能融合控制策略.总结了复杂硫化过程中的控制难点,探讨了硫化过程的控制论特性,研究了对不确定性复杂过程的控制策略,讨论了控制模型,提出了智能融合控制策略,基于仿人智能构造了基本控制算法.仿真结果显示该策略的鲁棒性强与控制精度高.研究结果表明:智能融合控制策略对不确定性复杂硫化过程实施控制是可行与有效的.%The vulcanization of plastic & rubber products is a typical complex control process with uncertainty.Aimed at the puzzle that the shaping process of plastic & rubber products is difficult to control resulted from fuzzification and uncertainty,and poor in stability of product quality in the process of vulcanization,the paper proposed a sort of intelligence based control strategy based on human simulated intelligent controller.In the paper,it summed up the control puzzles in the process of complex vulcanization,explored the cybernetics characteristic of vulcanizing process,researched on the control strategy of complex process with uncertainty,proposed a sort of intelligence based control strategy,discussed control model,and constructed the control algorithm based on human simulated intelligence.It made the simulation experiment,and the curve of algorithm response demonstrated that it could be stronger in robustness,and higher in control precision compared with PID controller.The research result shows that it is feasible and effective to the proposed control strategy based on human simulated intelligence in actualizing control for complex vulcanizing process with uncertainty.

  2. Effectiveness and cost of recruitment strategies for a community-based randomised controlled trial among rainwater drinkers

    Directory of Open Access Journals (Sweden)

    Cunliffe David

    2009-07-01

    Full Text Available Abstract Background Community-based recruitment is challenging particularly if the sampling frame is not easily defined as in the case of people who drink rainwater. Strategies for contacting participants must be carefully considered to maximise generalisability and minimise bias of the results. This paper assesses the recruitment strategies for a 1-year double-blinded randomised trial on drinking untreated rainwater. The effectiveness of the recruitment strategies and associated costs are described. Methods Community recruitment of households from Adelaide, Australia occurred from February to July 2007 using four methods: electoral roll mail-out, approaches to schools and community groups, newspaper advertising, and other media involvement. Word of mouth communication was also assessed. Results A total of 810 callers were screened, with 53.5% eligible. Of those who were eligible and sent further information, 76.7% were willing to participate in the study and 75.1% were enrolled. The target for recruitment was 300 households, and this was achieved. The mail-out was the most effective method with respect to number of households randomised, while recruitment via schools had the highest yield (57.3% and was the most cost effective when considering cost per household randomised (AUD$147.20. Yield and cost effectiveness were lowest for media advertising. Conclusion The use of electoral roll mail-out and advertising via schools were effective in reaching households using untreated rainwater for drinking. Employing multiple strategies enabled success in achieving the recruitment target. In countries where electoral roll extracts are available to researchers, this method is likely to have a high yield for recruitment into community-based epidemiological studies.

  3. An Optimal Reactive Power Control Strategy for a DFIG-Based Wind Farm to Damp the Sub-Synchronous Oscillation of a Power System

    Directory of Open Access Journals (Sweden)

    Bin Zhao

    2014-05-01

    Full Text Available This study presents the auxiliary damping control with the reactive power loop on the rotor-side converter of doubly-fed induction generator (DFIG-based wind farms to depress the sub-synchronous resonance oscillations in nearby turbogenerators. These generators are connected to a series capacitive compensation transmission system. First, the damping effect of the reactive power control of the DFIG-based wind farms was theoretically analyzed, and a transfer function between turbogenerator speed and the output reactive power of the wind farms was introduced to derive the analytical expression of the damping coefficient. The phase range to obtain positive damping was determined. Second, the PID phase compensation parameters of the auxiliary damping controller were optimized by a genetic algorithm to obtain the optimum damping in the entire subsynchronous frequency band. Finally, the validity and effectiveness of the proposed auxiliary damping control were demonstrated on a modified version of the IEEE first benchmark model by time domain simulation analysis with the use of DigSILENT/PowerFactory. Theoretical analysis and simulation results show that this derived damping factor expression and the condition of the positive damping can effectively analyze their impact on the system sub-synchronous oscillations, the proposed wind farms reactive power additional damping control strategy can provide the optimal damping effect over the whole sub-synchronous frequency band, and the control effect is better than the active power additional damping control strategy based on the power system stabilizator.

  4. Environmental Process Control: Strategies and Implementation

    Directory of Open Access Journals (Sweden)

    Jurgis Staniskis

    2006-04-01

    Full Text Available The structure and mathematical presentation of the optimal strategy for environmental process control is presented. This approach covers a wide variety of control systems, which have been constructed and analysed at the Institute of Environmental Engineering during the last fifteen years. Special attention is paid to the preventive environmental control and its tools: pollution prevention, life cycle assessment. The implementation results of preventive environmental control from more than 150 companies are presented in the paper.The investigations on water quality control issues are evaluated from the point of view of the interface between physico-ecological and socio-economical systems and decision support system based on river water quality model is suggested.

  5. Short Horizon Control Strategies for an Alternating Activated Sludge Process

    DEFF Research Database (Denmark)

    Isaacs, Steven Howard

    1996-01-01

    Three control strategies allowing improved operational flexibility of an alternating type activated sludge process are presented in a unified model based framework. The control handles employed are the addition rate of an external carbon source to denitrification, the cycle length...

  6. A Hierarchical Reliability Control Method for a Space Manipulator Based on the Strategy of Autonomous Decision-Making

    Directory of Open Access Journals (Sweden)

    Xin Gao

    2016-01-01

    Full Text Available In order to maintain and enhance the operational reliability of a robotic manipulator deployed in space, an operational reliability system control method is presented in this paper. First, a method to divide factors affecting the operational reliability is proposed, which divides the operational reliability factors into task-related factors and cost-related factors. Then the models describing the relationships between the two kinds of factors and control variables are established. Based on this, a multivariable and multiconstraint optimization model is constructed. Second, a hierarchical system control model which incorporates the operational reliability factors is constructed. The control process of the space manipulator is divided into three layers: task planning, path planning, and motion control. Operational reliability related performance parameters are measured and used as the system’s feedback. Taking the factors affecting the operational reliability into consideration, the system can autonomously decide which control layer of the system should be optimized and how to optimize it using a control level adjustment decision module. The operational reliability factors affect these three control levels in the form of control variable constraints. Simulation results demonstrate that the proposed method can achieve a greater probability of meeting the task accuracy requirements, while extending the expected lifetime of the space manipulator.

  7. Market-based control strategy for long-span structures considering the multi-time delay issue

    Science.gov (United States)

    Li, Hongnan; Song, Jianzhu; Li, Gang

    2017-01-01

    To solve the different time delays that exist in the control device installed on spatial structures, in this study, discrete analysis using a 2 N precise algorithm was selected to solve the multi-time-delay issue for long-span structures based on the market-based control (MBC) method. The concept of interval mixed energy was introduced from computational structural mechanics and optimal control research areas, and it translates the design of the MBC multi-time-delay controller into a solution for the segment matrix. This approach transforms the serial algorithm in time to parallel computing in space, greatly improving the solving efficiency and numerical stability. The designed controller is able to consider the issue of time delay with a linear controlling force combination and is especially effective for large time-delay conditions. A numerical example of a long-span structure was selected to demonstrate the effectiveness of the presented controller, and the time delay was found to have a significant impact on the results.

  8. Improved Control Strategies for a DFIG-Based Wind-Power Generation System with SGSC under Unbalanced and Distorted Grid Voltage Conditions

    DEFF Research Database (Denmark)

    Yao, Jun; Yu, Mengting; Hu, Weihao

    2016-01-01

    This paper investigates an improved control strategy for a doubly-fed induction generator (DFIG) based wind-power generation system with series grid-side converter (SGSC) under network unbalance and harmonic grid voltage distortion conditions. The integrated mathematical modeling of the DFIG system...... with SGSC is established by taking both the negative-sequence and harmonic components of the grid voltages into consideration with multiple synchronous rotating reference frames. Under network unbalance and harmonic distortion situations, stator voltage can be kept symmetrical and sinusoidal by the control...... references are calculated. In addition, the allocation principles for the PGSC’s current references are proposed by taking into account the PGSC's current rating limit. The impact of PGSC’s current limit on the proposed control strategies have been investigated in detail. Furthermore, a PI regulator...

  9. The Milling Assistant, Case-Based Reasoning, and machining strategy: A report on the development of automated numerical control programming systems at New Mexico State University

    Energy Technology Data Exchange (ETDEWEB)

    Burd, W. [Sandia National Labs., Albuquerque, NM (United States); Culler, D.; Eskridge, T.; Cox, L.; Slater, T. [New Mexico State Univ., Las Cruces, NM (United States)

    1993-08-01

    The Milling Assistant (MA) programming system demonstrates the automated development of tool paths for Numerical Control (NC) machine tools. By integrating a Case-Based Reasoning decision processor with a commercial CAD/CAM software, intelligent tool path files for milled and point-to-point features can be created. The operational system is capable of reducing the time required to program a variety of parts and improving product quality by collecting and utilizing ``best of practice`` machining strategies.

  10. The Virtual Resistance Control Strategy for HVRT of Doubly Fed Induction Wind Generators Based on Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Zhen Xie

    2014-01-01

    Full Text Available Grid voltage swell will cause transient DC flux component in the doubly fed induction generator (DFIG stator windings, creating serious stator and rotor current and torque oscillation, which is more serious than influence of the voltage dip. It is found that virtual resistance manages effectively to suppress rotor current and torque oscillation, avoid the operation of crowbar circuit, and enhance its high voltage ride through technology capability. In order to acquire the best virtual resistance value, the excellent particle library (EPL of dynamic particle swarm optimization (PSO algorithm is proposed. It takes the rotor voltage and rotor current as two objectives, which has a fast convergence performance and high accuracy. Simulation and experimental results verify the effectiveness of the virtual resistance control strategy.

  11. Night ventilation control strategies in office buildings

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhaojun; Yi, Lingli; Gao, Fusheng [School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090 (China)

    2009-10-15

    In moderate climates night ventilation is an effective and energy-efficient approach to improve the indoor thermal environment for office buildings during the summer months, especially for heavyweight construction. However, is night ventilation a suitable strategy for office buildings with lightweight construction located in cold climates? In order to answer this question, the whole energy-consumption analysis software EnergyPlus was used to simulate the indoor thermal environment and energy consumption in typical office buildings with night mechanical ventilation in three cities in northern China. The summer outdoor climate data was analyzed, and three typical design days were chosen. The most important factors influencing night ventilation performance such as ventilation rates, ventilation duration, building mass and climatic conditions were evaluated. When night ventilation operation time is closer to active cooling time, the efficiency of night ventilation is higher. With night ventilation rate of 10 ach, the mean radiant temperature of the indoor surface decreased by up to 3.9 C. The longer the duration of operation, the more efficient the night ventilation strategy becomes. The control strategies for three locations are given in the paper. Based on the optimized strategies, the operation consumption and fees are calculated. The results show that more energy is saved in office buildings cooled by a night ventilation system in northern China than ones that do not employ this strategy. (author)

  12. Force Control Strategies in Hydraulically Actuated Legged Robots

    Directory of Open Access Journals (Sweden)

    Hector Montes

    2016-03-01

    Full Text Available In this contribution, several strategies of force control have been proposed to be implemented and evaluated in ROBOCLIMBER, a quadruped robot of large dimensions. A first group of strategies proposed in this paper is based on impedance control, which is intended to adapt the foot-ground contact forces according to the experimentally specified damping ratio and the undamped natural frequency. A second control strategy of interest for many practical cases is called the parallel force/position control, which has one inner loop position control and two external control loops, one of force and another of position. A third group of control strategies is the posture stabilization for ROBOCLIMBER using the feedback of the ZMP calculation and the position of its legs. Finally, a control strategy for the control of a quasi-static gait using ZMP feedback is proposed and tested by simulation.

  13. Fuzzy Control Strategies in Human Operator and Sport Modeling

    CERN Document Server

    Ivancevic, Tijana T; Markovic, Sasa

    2009-01-01

    The motivation behind mathematically modeling the human operator is to help explain the response characteristics of the complex dynamical system including the human manual controller. In this paper, we present two different fuzzy logic strategies for human operator and sport modeling: fixed fuzzy-logic inference control and adaptive fuzzy-logic control, including neuro-fuzzy-fractal control. As an application of the presented fuzzy strategies, we present a fuzzy-control based tennis simulator.

  14. Enhanced porcine circovirus Cap protein production by Pichia pastoris with a fuzzy logic DO control based methanol/sorbitol co-feeding induction strategy.

    Science.gov (United States)

    Ding, Jian; Zhang, Chunling; Gao, Minjie; Hou, Guoli; Liang, Kexue; Li, Chunhua; Ni, Jianping; Li, Zhen; Shi, Zhongping

    2014-05-10

    Porcine circovirus Cap protein production by P. pastoris with strong AOX promoter suffered with the problems with traditional pure methanol induction: (1) inefficient methanol metabolism; (2) extensive oxygen supply load; (3) difficulty in stable DO control; (4) low protein titer. In this study, based on the difference of DO change patterns in response to methanol and sorbitol additions, a novel fuzzy control system was proposed to automatically regulate the co-feeding rates of methanol and sorbitol for efficient Cap protein induction. With aid of the proposed control system when setting DO control level at 10%, overall fermentation performance was significantly improved: (1) DO could be stably controlled under mild aeration condition; (2) methanol consumption rate could be restricted at moderate level and the major enzymes involved with methanol metabolism were largely activated; (3) Cap protein concentration reached a highest level of 198mg/L, which was about 64% increase over the best one using the pure methanol induction strategies.

  15. Active steering control strategy for articulated vehicles

    Institute of Scientific and Technical Information of China (English)

    Kyong-il KIM; Hsin GUAN; Bo WANG; Rui GUO; Fan LIANG

    2016-01-01

    To improve maneuverability and stability of articulated vehicles, we design an active steering controller, including tractor and trailer controllers, based on linear quadratic regulator (LQR) theory. First, a three-degree-of-freedom (3-DOF) model of the tractor-trailer with steered trailer axles is built. The simulated annealing particle swarm optimization (SAPSO) algorithm is applied to identify the key parameters of the model under specified vehicle speed and steering wheel angle. Thus, the key pa-rameters of the simplified model can be obtained according to the vehicle conditions using an online look-up table and interpola-tion. Simulation results show that vehicle parameter outputs of the simplified model and TruckSim agree well, thus providing the ideal reference yaw rate for the controller. Then the active steering controller of the tractor and trailer based on LQR is designed to follow the desired yaw rate and minimize their side-slip angle of the center of gravity (CG) at the same time. Finally, simulation tests at both low speed and high speed are conducted based on the TruckSim-Simulink program. The results show significant effects on the active steering controller on improving maneuverability at low speed and lateral stability at high speed for the articulated vehicle. The control strategy is applicable for steering not only along gentle curves but also along sharp curves.

  16. A Control Strategy for Photovoltaic-Solid Polymer Electrolysis System Based on Surface Temperature of PV Panel

    Directory of Open Access Journals (Sweden)

    Riza Muhida

    2008-01-01

    Full Text Available Processes to produce hydrogen from solar photovoltaic powered water electrolysis using solid polymer electrolysis are reported. An alternative control of maximum power point tracking method based on analysis of PV panel’s surface Temperature for the PV-SPE system was designed and implemented. From this analysis an optimal voltage of PV can be obtained and was realized as a reference voltage of Dc-DC converter. By maintenance the output voltage of PV using the reference voltage control, the output PV can be optimized at its MPP operation. The MPPT performance and hydrogen production performance of this method have been evaluated and discussed based on the results of the experiment.

  17. A Power Smoothing Control Strategy and Optimized Allocation of Battery Capacity Based on Hybrid Storage Energy Technology

    Directory of Open Access Journals (Sweden)

    Yong Li

    2012-05-01

    Full Text Available Wind power parallel operation is an effective way to realize the large scale use of wind power, but the fluctuations of power output from wind power units may have great influence on power quality, hence a new method of power smoothing and capacity optimized allocation based on hybrid energy storage technology is proposed in terms of the uncontrollable and unexpected characteristics of wind speed in wind farms. First, power smoothing based on a traditional Inertial Filter is introduced and the relationship between the time constant, its smoothing effect and capacity allocation are analyzed and combined with Proportional Integral Differential (PID control to realize power smoothing control of wind power. Then wavelet theory is adopted to realize a multi-layer decomposition of power output in some wind farms, a power smoothing model based on hybrid energy storage technology is constructed combining the characteristics of the Super Capacitor (SC and Battery Energy Storage System (BESS technologies. The hybrid energy storage system is available for power fluctuations with high frequency-low energy and low frequency-high energy to achieve good smoothing effects compared with a single energy storage system. The power fluctuations filtered by the Wavelet Transform is regarded as the target value of BESS, the charging and discharging control for battery is completed quickly by Model Algorithm Control (MAC. Because of the influence of the inertia and the response speed of the battery, its actual output is not completely equal to the target value which mainly reflects in high-frequency part, the difference part uses SC to compensate and makes the output of battery and SC closer to the target value on the whole. Compared with the traditional Inertial Filter and PID control method, the validity of the model was verified by simulation results. Finally under the premise of power grid standards, the corresponding capacity design had been given to reduce the

  18. A Strategy for Quality Control of Menispermum dauricum DC Based on Cytotoxic Activity and HPLC Fingerprint Analysis.

    Science.gov (United States)

    Liu, L J; Liu, J N

    2016-01-01

    The rhizome of Menispermum dauricum DC known as a traditional Chinese medicine, with high content of alkaloids, has been found to possess antitumor activity. In this research, an attempt to correlate fingerprinting with bioactivity was made for quality control of M. dauricum. Firstly, the cytotoxicity of extracts from ten batches of samples against human breast MCF-7 cancer cells was estimated by [3-(4, 5-dimethylthiazole-2-yl)-2, 5-diphenyltetrazoliumbromide] assay. Then, cytotoxic activity-integrated fingerprints were established by high performance liquid chromatography. Eight peaks were selected as the common peaks to evaluate the similarities of samples and hierarchical clustering analysis was used to identify and classify different samples into groups. Assays for determinations of total alkaloids and dauricine contents enabled cytotoxicity coefficient of each extract. The potential usefulness of employing cytotoxicity coefficient was investigated by a combination of Pearson correlation coefficients and multiple linear regression analysis as being the reliable parameter to evaluate the herbal extracts. The results indicated that the level of dauricine (peak 8 in the fingerprint) correlated closely with cytotoxicity and played a significant role in the cytotoxicity of Bei Dou-Gen and could be related to its antitumor properties. It is proposed that the cytotoxicity coefficient value with a cytotoxic activity-integrated fingerprint of key biomarkers (dauricine) may be useful indicators to adopt for the quality control of M. dauricum. The analysis of cytotoxic-activity-integrated fingerprint could correlate fingerprinting with bioactivities and would provide a reasonable strategy for quality control of complex mixture of herbal medicines.

  19. 40 CFR 52.1582 - Control strategy and regulations: Ozone.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy and regulations: Ozone... Control strategy and regulations: Ozone. (a) Subchapter 16 of the New Jersey Administrative Code, entitled... of the 1990 Clean Air Act. (d)(1) The base year ozone precursor emission inventory requirement...

  20. Control Strategy Tool (CoST)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The EPA Control Strategy Tool (CoST) is a software tool for projecting potential future control scenarios, their effects on emissions and estimated costs. This tool...

  1. Neural PID Control Strategy for Networked Process Control

    Directory of Open Access Journals (Sweden)

    Jianhua Zhang

    2013-01-01

    Full Text Available A new method with a two-layer hierarchy is presented based on a neural proportional-integral-derivative (PID iterative learning method over the communication network for the closed-loop automatic tuning of a PID controller. It can enhance the performance of the well-known simple PID feedback control loop in the local field when real networked process control applied to systems with uncertain factors, such as external disturbance or randomly delayed measurements. The proposed PID iterative learning method is implemented by backpropagation neural networks whose weights are updated via minimizing tracking error entropy of closed-loop systems. The convergence in the mean square sense is analysed for closed-loop networked control systems. To demonstrate the potential applications of the proposed strategies, a pressure-tank experiment is provided to show the usefulness and effectiveness of the proposed design method in network process control systems.

  2. Robust missile feedback control strategies

    NARCIS (Netherlands)

    Trottemant, E.J.; Scherer, C.W.; Weiss, M.; Vermeulen, A.

    2010-01-01

    The nature of the missile interception problem with two noncooperative players leads to the field of differential games. Introducing nonlinear uncertain models can potentially lead to nonexistence of game theoretic equilibrium strategies, computationally intractable problems, and/or highly reduced p

  3. Speciated OVOC and VOC emission inventories and their implications for reactivity-based ozone control strategy in the Pearl River Delta region, China.

    Science.gov (United States)

    Ou, Jiamin; Zheng, Junyu; Li, Rongrong; Huang, Xiaobo; Zhong, Zhuangmin; Zhong, Liuju; Lin, Hui

    2015-10-15

    The increasing ground-ozone (O3) levels, accompanied by decreasing SO2, NO2, PM10 and PM2.5 concentrations benefited from air pollution control measures implemented in recent years, initiated a serious challenge to control Volatile Organic Compound (VOC) emissions in the Pearl River Delta (PRD) region, China. Speciated VOC emission inventory is fundamental for estimating Ozone Formation Potentials (OFPs) to identify key reactive VOC species and sources in order to formulate efficient O3 control strategies. With the use of the latest bulk VOC emission inventory and local source profiles, this study developed the PRD regional speciated Oxygenated Volatile Organic Compound (OVOC) and VOC emission inventories to identify the key emission-based and OFP-based VOC sources and species. Results showed that: (1) Methyl alcohol, acetone and ethyl acetate were the major constituents in the OVOC emissions from industrial solvents, household solvents, architectural paints and biogenic sources; (2) from the emission-based perspective, aromatics, alkanes, OVOCs and alkenes made up 39.2%, 28.2%, 15.9% and 10.9% of anthropogenic VOCs; (3) from the OFP-based perspective, aromatics and alkenes become predominant with contributions of 59.4% and 25.8% respectively; (4) ethene, m/p-xylene, toluene, 1,2,4-trimethyl benzene and other 24 high OFP-contributing species were the key reactive species that contributed to 52% of anthropogenic emissions and up to 80% of OFPs; and (5) industrial solvents, industrial process, gasoline vehicles and motorcycles were major emission sources of these key reactive species. Policy implications for O3 control strategy were discussed. The OFP cap was proposed to regulate VOC control policies in the PRD region due to its flexibility in reducing the overall OFP of VOC emission sources in practice.

  4. Public authority control strategy for opinion evolution in social networks

    Science.gov (United States)

    Chen, Xi; Xiong, Xi; Zhang, Minghong; Li, Wei

    2016-08-01

    This paper addresses the need to deal with and control public opinion and rumors. Existing strategies to control public opinion include degree, random, and adaptive bridge control strategies. In this paper, we use the HK model to present a public opinion control strategy based on public authority (PA). This means utilizing the influence of expert or high authority individuals whose opinions we control to obtain the optimum effect in the shortest time possible and thus reach a consensus of public opinion. Public authority (PA) is only influenced by individuals' attributes (age, economic status, and education level) and not their degree distribution; hence, in this paper, we assume that PA complies with two types of public authority distribution (normal and power-law). According to the proposed control strategy, our experiment is based on random, degree, and public authority control strategies in three different social networks (small-world, scale-free, and random) and we compare and analyze the strategies in terms of convergence time (T), final number of controlled agents (C), and comprehensive efficiency (E). We find that different network topologies and the distribution of the PA in the network can influence the final controlling effect. While the effect of PA strategy differs in different network topology structures, all structures achieve comprehensive efficiency with any kind of public authority distribution in any network. Our findings are consistent with several current sociological phenomena and show that in the process of public opinion/rumor control, considerable attention should be paid to high authority individuals.

  5. Strategies For Malaria Control In Mangalore City

    Directory of Open Access Journals (Sweden)

    Kiran Udaya .N

    1999-01-01

    Full Text Available Research questions: What different strategies should be used to effectively control problem of malaria? Objectives: 1 To study the problem of malaria. 2 To study different strategies for effective control of malaria. Study design: Observational and record based. The problem of malaria was studied for three years from 1996-1998 Participants: Individuals having fever. Setting: Community based in Mangalore City. Study variables: Fever cases, blood slides prepared, slides found positive, agency-wise, species-wise and year-wise positivity. Statistical methods: Simple proportions. Results: The yield of cases has been shown to highest in passive surveillance, as reflected in high slide positivity rates. A total of 95,898 slides were prepared, out of which 19,169 were positive for malaria parasite. Thus, the overall side positivity was 20%. The SPR in passive surveillance was 34.5%. Month-wise distribution of positive cases showed high SPR and low Pv/Pf ratios during non-malaria seasons. It is suggested to improve passive surveillance to achieve high SPR thereby leading to substantial saving on slides, laboratory services and transport expenditure.

  6. Coordinated control strategy based on reactive power flow in UPQC%基于无功功率流的UPQC协调控制策略

    Institute of Scientific and Technical Information of China (English)

    冯兴田; 马文忠; 霍群海

    2013-01-01

    针对统一电能质量调节器UPQC常规控制中,其串并联变流器功能相对独立、利用率低的问题,提出基于无功功率流的UPQC协调控制策略.应用所设计的UPQC系统结构,协调分配UPQC串并联变流器的无功功率输出,控制串联变流器输出电压向量垂直相应的电流向量,控制并联变流器输出电流向量垂直相应的电压向量,有效消除了有功环流的影响.特别针对电网侧没有电能质量问题时,控制串联变流器继续输出无功功率,充分发挥两变流器的无功补偿功能.理论推导UPQC系统功率流的关系,并仿真实验分析提出的控制策略,结果表明该控制策略解决电能质量问题的同时,实现了UPQC串并联变流器功率的合理分配.%According to the relatively independent functions and low utilization rate of the unified power quality conditioner ( UPQC) series and parallel converters in UPQC regular control, the UPQC control strategy based on reactive power flow is provided. With the designed UPQC structure, the strategy real ized the coordinate distribution of the reactive power output of the UPQC series and parallel converters. The influence of active power circulation was effectively eliminated by controlling output voltage vector of the series converter perpendicular to the corresponding current vector and output current vector of the par allel converter perpendicular to the corresponding voltage vector. Especially when there is no power quali ty problem of the grid side, the strategy controlled the series converter to continue reactive power output and fully played the reactive power compensation function of both converters. The relationship of UPQC system power flow was theoretical deduced and the proposing control strategy was analyzed by simulation and experiment. The results show that the control strategy solves the power quality problems and realizes the rational power allocation of the UPQC series and parallel converters.

  7. Control strategies for aircraft airframe noise reduction

    Institute of Scientific and Technical Information of China (English)

    Li Yong; Wang Xunnian; Zhang Dejiu

    2013-01-01

    With the development of low-noise aircraft engine,airframe noise now represents a major noise source during the commercial aircraft's approach to landing phase.Noise control efforts have therefore been extensively focused on the airframe noise problems in order to further reduce aircraft overall noise.In this review,various control methods explored in the last decades for noise reduction on airframe components including high-lift devices and landing gears are summarized.We introduce recent major achievements in airframe noise reduction with passive control methods such as fairings,deceleration plates,splitter plates,acoustic liners,slat cove cover and side-edge replacements,and then discuss the potential and control mechanism of some promising active flow control strategies for airframe noise reduction,such as plasma technique and air blowing/suction devices.Based on the knowledge gained throughout the extensively noise control testing,a few design concepts on the landing gear,high-lift devices and whole aircraft are provided for advanced aircraft low-noise design.Finally,discussions and suggestions are given for future research on airframe noise reduction.

  8. Nitrate control strategies in an activated sludge wastewater treatment process

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Wenhao; Tao, Erpan; Chen, Xiaoquan; Liu, Dawei [South China University of Technology, Guangzhou (China); Liu, Hongbin [Kyung Hee University, Yongin (Korea, Republic of)

    2014-03-15

    We studied nitrate control strategies in an activated sludge wastewater treatment process (WWTP) based on the activated sludge model. Two control strategies, back propagation for proportional-integral-derivative (BP-PID) and adaptive-network based fuzzy inference systems (ANFIS), are applied in the WWTP. The simulation results show that the simple local constant setpoint control has poor control effects on the nitrate concentration control. However, the ANFIS (4*1) controller, which considers not only the local constant setpoint control of the nitrate concentration, but also three important indices in the effluent--ammonia concentration, total suspended sludge concentration and total nitrogen concentration--demonstrates good control performance. The results also prove that ANFIS (4*1) controller has better control performance than that of the controllers PI, BP-PID and ANFIS (2*1), and that the ANFIS (4*1) controller is effective in improving the effluent quality and maintaining the stability of the effluent quality.

  9. Development of sensor-less control strategies for grid connected PMSG based variable speed wind energy conversion system with improved power quality features

    Energy Technology Data Exchange (ETDEWEB)

    Chandra, A. [Quebec Univ., Montreal, PQ (Canada). Dept. of Electrical Engineering

    2010-07-01

    Interest in renewable energy sources has grown in recent years in response to concerns of increasing pollution levels and depleting fossil fuels. Among renewable energy sources, wind energy generation is the fastest growing technology and one of the most cost-effective and environmental friendly means to generate electricity from renewable sources. Modern wind turbines are ready to be deployed in large scale as a result of recent developments in wind power technology. Variable speed permanent magnet synchronous generators (PMSG) based wind energy conversion systems (WECS) are becoming more popular. The use of a permanent magnet reduces size, cost and weight of overall WECS. In addition, the absence of field winding and its excitation system avoids heat dissipation in the rotor winding, thereby improving overall efficiency of the WECS. This type of configuration is more appropriate for remote locations, particularly for off-shore wind application, where the geared doubly fed induction generator usually requires regular maintenance due to tearing-wearing in brushes, windings and gear box. This presentation discussed the development of sensor-less control strategies for grid connected PMSG based variable speed wind energy conversion system with improved power quality features. A novel adaptive network-based fuzzy inference system was used to estimate the speed and position of variable speed PMSG under fluctuating wind conditions. A novel control strategy was developed for the grid interfacing inverter incorporating power quality improvement features at point of common coupling.

  10. Extending satisficing control strategy to slowly varying nonlinear systems

    Science.gov (United States)

    Binazadeh, T.; Shafiei, M. H.

    2013-04-01

    Based on the satisficing control strategy, a novel approach to design a stabilizing control law for nonlinear time varying systems with slowly varying parameters (slowly varying systems) is presented. The satisficing control strategy has been originally introduced for time-invariant systems; however, this technique does not have any stability proof for time varying systems. In this paper, first, a parametric version of the satisficing control strategy is developed. Then, by considering the time as a frozen parameter, the parametric satisficing control strategy is utilized. Finally, a theorem is presented which suggested a stabilizing satisficing control law for the slowly varying control systems. Moreover, in this theorem, the maximum admissible rate of change of the system dynamics is evaluated. The efficiency of the proposed approach is demonstrated by a computer simulation.

  11. Hierarchical Control Strategy for the Cooperative Braking System of Electric Vehicle

    OpenAIRE

    Jiankun Peng; Hongwen He; Wei Liu; Hongqiang Guo

    2015-01-01

    This paper provides a hierarchical control strategy for cooperative braking system of an electric vehicle with separated driven axles. Two layers are defined: the top layer is used to optimize the braking stability based on two sliding mode control strategies, namely, the interaxle control mode and signal-axle control strategies; the interaxle control strategy generates the ideal braking force distribution in general braking condition, and the single-axle control strategy can ensure braking s...

  12. Grid control strategy of wind turbine based on double voltage source rectifier%基于双VSR的风电机组并网控制策略

    Institute of Scientific and Technical Information of China (English)

    葛俊旭; 李鑫; 童水光; 吴德忠; 田志刚; 王鹏

    2011-01-01

    针对兆瓦级永磁同步发电机组并网的控制要求,基于三相电压型脉宽调制(PWM)整流器的数学模型,重点研究了直接电流控制双闭环级联结构的三相电压型PWM整流器和基于SVPWM的三相电压型PWM整流器的控制系统设计,提出基于双电压型PWM整流器(VSR)的风力发电机组的并网控制策略,并建立该控制策略的等效电路模型.通过对该并网控制策略等效电路模型的仿真分析,验证了PWM整流器的升压整流特性;同时,该等效电路输出的三相交流相电流总谐波畸变率仅为1.64%,电流波形正弦度良好.仿真结果验证了该并网控制策略的可行性.%For grid control of permanent magneticm synchronous generator, according to the mathematcalmodel of three-phase voltage source rectifier, this work emphatically studied the controller design of three-phase voltage source rectifier(VSR), which has double closed-loop and cascade structure based on the direct current control, and voltage source rectifier based on space vector pulse width modulation. The grid control strategy based on double voltage source rectifier for wind turbine generators was and proposed the corresponding equivalent circuit model was established. The simulation to this grid control strategy's equivalent circuit proved the rising voltage speciality of pulse width modulation (PWM). The current's total harmonic distortion of the grid side output's three-phase AC interphase was only 1.64%, and its waveform was batter. The new control strategy was proved feasible by Simulink simulation.

  13. Control strategies for friction dampers: numerical assessment and experimental investigations.

    Directory of Open Access Journals (Sweden)

    Coelho H.T.

    2014-01-01

    Full Text Available The use of friction dampers has been proposed in a wide variety of mechanical systems for which it is not possible to apply viscoelastic materials, fluid based dampers or others viscous dampers. An important example is the application of friction dampers in aircraft engines to reduce the blades vibration amplitudes. In most cases, friction dampers have been studied in a passive way, however, a significant improvement can be achieved by controlling the normal force in the dampers. The aim of this paper is to study three control strategies for friction dampers based on the hysteresis cycle. The first control strategy maximizes the energy removal in each harmonic oscillation cycle, by calculating the optimum normal force based on the last displacement peak. The second control strategy combines the first one with the maximum energy removal strategy used in the smart spring devices. Finally, is presented the strategy which homogenously modulates the friction force. Numerical studies were performed with these three strategies defining the performance metrics. The best control strategy was applied experimentally. The experimental test rig was fully identified and its parameters were used for the numerical simulations. The obtained results show the good performance for the friction damper and the selected strategy.

  14. Control Strategy for Cascaded Medium - High Voltage STATCOM

    Directory of Open Access Journals (Sweden)

    Libing Chen

    2013-12-01

    Full Text Available Control strategy is researched for cascaded medium high static synchronous compensator to provide synthetic compensation ability of reactive power, harmonics and asymmetric currents. Basing on selective harmonic compensation strategy, a reference current detection method utilizing the combination of synchronous reference frame transformation and discrete Fourier transformation is proposed. The tracking control of instruction current is implemented by multi-carrier pulse width modulation (PWM. In allusion to the multi-carrier PWM, the capacitor voltage balancing control at the dc side is realized by a type of software based on the energy balance principle of the inverter bridge. The proposed control strategy is convenient for engineering implementation given its low calculation burden and simplicity. The effectiveness of the proposed control strategy is proven by both simulation and experimental results.

  15. A review on development of novel strategies for controlling Salmonella Enteritidis colonization in laying hens: fiber-based molt diets.

    Science.gov (United States)

    Ricke, S C; Dunkley, C S; Durant, J A

    2013-02-01

    Limiting Salmonella Enteritidis from table eggs can involve intervention approaches at several levels of the production cycle, beginning at the hatchery and ending at the processing or table egg production facilities. Likewise, interventions that limit Salmonella Enteritidis dissemination can be implemented at various stages during the life cycle of infection of Salmonella in the laying hen. However, achieving complete elimination of Salmonella infestation in egg products has remained elusive. There is a multitude of reasons for this, including adaptability of the organism, virulence properties, and persistence. Likewise, environmental factors in the layer house such as transmission routes, reservoirs, and feed sources can influence the exposure of susceptible laying hens to Salmonella Enteritidis. Consequently, successful applications of control measures depend not only on the timing of when they are applied but also on effective surveillance to detect frequency and level of infection of Salmonella. Several studies demonstrated that molt induction by feed withdrawal altered the immune system and the gastrointestinal tract of hens, making them susceptible to Salmonella Enteritidis colonization of the gastrointestinal tract. To alleviate this, the development of alternative methods to induce a molt became necessary. The use of several fiber-containing diets was shown to effectively induce a molt with alfalfa-based diets being the most extensively studied. Further reduction of Salmonella Enteritidis levels in eggs will probably require application of multiple interventions at several steps during egg production and processing as well as a better understanding of the mechanisms used by Salmonella Enteritidis to persist in laying flocks.

  16. Start up partial nitrification at low temperature with a real-time control strategy based on blower frequency and pH.

    Science.gov (United States)

    Gu, Shengbo; Wang, Shuying; Yang, Qing; Yang, Pei; Peng, Yongzhen

    2012-05-01

    In this study, the performance of partial nitrification via nitrite at low temperature was investigated in a pilot-scale sequencing batch reactor (SBR) with a working volume of 7.0m(3). A novel real-time control strategy, based on blower frequency (BF) and pH, was designed and evaluated. The nitrogen break point (NBP) in the BF curve and the nitrate/nitrite apex point (NAP) in the pH curve were used to identify the endpoint of the aerobic and anoxic phases, respectively. The nitrite accumulation rate (NAR) rapidly increased from 19.8% to 90%. Partial nitrification was achieved at low temperature (11-16°C) in 40 days and was stably maintained for as long as 140 days by applying a real-time control strategy based on pH and BF. Fluorescence in situ hybirdization (FISH) results demonstrated that ammonia oxidation bacteria (AOB) had developed into the dominant nitrifying bacteria compared to nitrite oxidation bacteria (NOB) in the system.

  17. Strategies for glucose control in people with type 1 diabetes

    DEFF Research Database (Denmark)

    Boiroux, Dimitri; Finan, Daniel Aaron; Jørgensen, John Bagterp

    2011-01-01

    In this paper we apply a robust feedforward-feedback control strategy to people with type 1 diabetes. The feedforward controller consists of a bolus calculator which compensates the disturbance coming from meals. The feedback controller is based on a linearized description of the model describing...

  18. 基于限时脉冲控制害虫策略的Gompertz模型%Time-limited Pest Impulsive Control Strategy based on Gompertz Model

    Institute of Scientific and Technical Information of China (English)

    徐为坚; 陈时东

    2011-01-01

    基于在限定时间内控制害虫的策略,建立具有Gompertz增长的脉冲微分方程模型,得到该模型的边值解存在的条件,给出计算最大脉冲周期的方法,解决在限定时间内将害虫密度控制在经济阈值之下的问题.%Based on the time-limited pest control strategy,we construct the model of impulsive differential equation with Gompertz growth,and obtain the existence condition of the solution to the boundary value problem of the model.Furthermore,we present the method that can be used to calculate the maximum impulsive period,and solve the problem about how to control the pest density within the economic threshold in a given time.

  19. A fault tolerant superheat control strategy for supermarket refrigeration systems

    DEFF Research Database (Denmark)

    Vinther, Kasper; Izadi-Zamanabadi, Roozbeh; Rasmussen, Henrik;

    2013-01-01

    in a plug & play fashion. The strategy is outlined by means of procedural steps as well as a flow chart that also illustrates the process of automatic tuning of the maximum slope-seeking controller. Test results are furthermore presented for a display case in a full scale CO2 supermarket refrigeration......In this paper, a fault tolerant control (FTC) strategy is proposed for evaporator superheat control in supermarket refrigeration systems. Conventional control uses a pressure and temperature sensor for this purpose, however, the pressure sensor can fail to function. A contingency control strategy......, based on a maximum slope-seeking control method and only a single temperature sensor, is developed to drive the evaporator outlet temperature to a level that gives a suitable superheat of the refrigerant. The FTC strategy requires no a priori system knowledge or additional hardware and functions...

  20. A versatile, non genetically modified organism (GMO)-based strategy for controlling low-producer mutants in Bordetella pertussis cultures using antigenic modulation.

    Science.gov (United States)

    Goffin, Philippe; Slock, Thomas; Smessaert, Vincent; De Rop, Philippe; Dehottay, Philippe

    2015-08-01

    The uncontrolled presence of non-producer mutants negatively affects bioprocesses. In Bordetella pertussis cultures, avirulent mutants emerge spontaneously and accumulate. We characterized the dynamics of accumulation using high-throughput growth assays and competition experiments between virulent and avirulent (bvg(-) ) isolates. A fitness advantage of bvg(-) cells was identified as the main driver for bvg(-) accumulation under conditions of high virulence factor production. Conversely, under conditions that reduce their expression (antigenic modulation), bvg(-) takeover could be avoided. A control strategy was derived, which consists in applying modulating conditions whenever virulence factor production is not required. It has a wide range of applications, from routine laboratory operations to vaccine manufacturing, where pertussis toxin yields were increased 1.4-fold by performing early pre-culture steps in modulating conditions. Because it only requires subtle modifications of the culture medium and does not involve genetic modifications, this strategy is applicable to any B. pertussis isolate, and should facilitate regulatory acceptance of process changes for vaccine production. Strategies based on the same concept, could be derived for other industrially relevant micro-organisms. This study illustrates how a sound scientific understanding of physiological principles can be turned into a practical application for the bioprocess industry, in alignment with Quality by Design principles.

  1. Novel Strategy to Control Transgene Expression Mediated by a Sendai Virus-Based Vector Using a Nonstructural C Protein and Endogenous MicroRNAs

    Science.gov (United States)

    Ohtaka, Manami; Nakanishi, Mahito

    2016-01-01

    Tissue-specific control of gene expression is an invaluable tool for studying various biological processes and medical applications. Efficient regulatory systems have been utilized to control transgene expression in various types of DNA viral or integrating viral vectors. However, existing regulatory systems are difficult to transfer into negative-strand RNA virus vector platforms because of significant differences in their transcriptional machineries. In this study, we developed a novel strategy for regulating transgene expression mediated by a cytoplasmic RNA vector based on a replication-defective and persistent Sendai virus (SeVdp). Because of the capacity of Sendai virus (SeV) nonstructural C proteins to specifically inhibit viral RNA synthesis, overexpression of C protein significantly reduced transgene expression mediated by SeVdp vectors. We found that SeV C overexpression concomitantly reduced SeVdp mRNA levels and genomic RNA synthesis. To control C expression, target sequences for an endogenous microRNA were incorporated into the 3′ untranslated region of the C genes. Incorporation of target sequences for miR-21 into the SeVdp vector restored transgene expression in HeLa cells by decreasing C expression. Furthermore, the SeVdp vector containing target sequences for let-7a enabled cell-specific control of transgene expression in human fibroblasts and induced pluripotent stem cells. Our findings demonstrate that SeV C can be used as an effective regulator for controlling transgene expression. This strategy will contribute to efficient and less toxic SeVdp-mediated gene transfer in various biological applications. PMID:27764162

  2. 基于发动机联合控制的AMT换挡控制策略%Research on Shifting Control Strategy Based on Engine Coordination Control of AMT

    Institute of Scientific and Technical Information of China (English)

    谢先平; 梅近仁; 李君; 王天生

    2012-01-01

    分析了AMT换挡类型,提出了基于CAN总线的发动机联合控制策略,即TCU通过CAN及ECU扭矩控制功能对发动机扭矩进行精确控制,同时基于发动机瞬态扭矩对离合器实现精确分离和接合控制.针对不同换挡工况给出了离合器分离/接合与发动机降扭/扭矩恢复协调控制策略,同时提出了选换挡过程动态调整转速控制策略.试验结果表明,所提策略可以增强AMT换挡过程的平顺性和动力性,减小离合器滑摩,且具有很好的鲁棒性,有助于提高AMT换挡品质.%AMT shifting type is analyzed in this paper, and an engine coordination control strategy based on CAN bus is proposed. During the shifting process, TCU carries out accurate engine torque control via CAN bus and utilizing ECU's torque control function, and meanwhile TCU implements accurate clutch engagement and disengagement control based on transient engine torque. Aiming at different shifting conditions, a coordination control strategy between clutch disengagement and engagement and engine torque decreasing and engine torque recovery is put forward. And meanwhile a dynamic engine speed control strategy aiming at shifting and selection process is proposed. The experiments indicate that the strategy is helpful to improve shifting dynamic performance and smoothness performance, reduce clutch friction loss. It has good robustness and is helpful to improve shifting quality of AMT.

  3. HTGR Resilient Control System Strategy

    Energy Technology Data Exchange (ETDEWEB)

    Lynne M. Stevens

    2010-09-01

    A preeminent objective for corporate and government organizations is the protection of major investments, which is attained by achieving state awareness, a comprehensive understanding of security and safety, for critical infrastructures. Given the dependence of critical infrastructure on control systems for automation, the integrity of these systems and their ability to provide owner/operators a high degree of state awareness is essential in attaining a high degree of investment protection and public acceptance. Operators as well as government are therefore burdened to ensure they have a timely understanding of the status of their plant or all plants, respectively, to ensure efficient operations and investment and public protection. “This characterization is a significant objective that must consider many aspects of instrumentation, control, and intelligent systems in order to achieve the required result. These aspects include sensory, communication, analysis, decision, and human system interfaces necessary to achieve fusion of data and presentation of results that will provide an understanding of what issues are important and why.

  4. 基于dSPACE的电动汽车控制策略研究%Control Strategy of the Electric Car Based on dSPACE

    Institute of Scientific and Technical Information of China (English)

    冯雪丽

    2015-01-01

    This paper analyzes the development status and function of domestic demand pure electric vehicle control systems,developed a vehicle control system development process,and were scheduled to traffic patterns,traffic control torque control strategy were analyzed. Then develop a vehicle control system overall structure and scheduling traffic patterns,combined with MATLAB/SIMULINK conducted to establish the model. Finally based on dSPACE driving mode scheduling simulation test,the accuracy of the models is verified.%首先分析了纯电动汽车整车控制系统的国内外发展现状及功能需求,制定了整车控制系统的开发流程,并分别对行车模式调度、行车转矩控制的控制策略进行了分析。然后制定了整车控制系统总体结构图,并对行车模式调度结合MATLAB/SIMU⁃LINK进行模型的建立。最后基于dSPACE行车模式调度仿真进行测试,验证模型的准确性。

  5. Element Tracking Strategies for Hot Strip Laminar Cooling Control

    Institute of Scientific and Technical Information of China (English)

    HAN Bin; ZHANG Zhong-ping; LIU Xiang-hua; WANG Guo-dong

    2005-01-01

    Feedforward control is the core to control function in the cooling process of hot strip. One of the most important tasks in feedforward control is to determine the arrival time of the strip at various locations on the runout table for effective control. Based on the principles of element tracking and tracking strategies for variable rolling speed and constant rolling speed, a simple diagonal tracking method for an existing hot strip mill was proposed and tested. The test results show that the proposed strategies are effective for improving tracking control.

  6. Research on Control Strategy of Offshore Wind Farm Based on DC Grid%基于DC-GRID的海上风电场控制策略研究

    Institute of Scientific and Technical Information of China (English)

    袁帅; 王平; 葛宝明

    2012-01-01

    The control strategy of offshore wind farm based on dc-grid was presented, including five VSWT-PMSGs, an offshore full bridge DC-DC converter and an onshore VSC inverter. Each PMSG was connected to the DC-bus. The voltage of DD-bus was stepped up by a Full Bridge DC-DC converter at the offshore HVDC station and then was inverted by the onshore VSC inverter to suit AC grid voltage. The effectiveness of the control strategy was verified by simulation analyses using Matlab/ Simulink.%提出了基于直流传输的海上风电场系统的控制策略,同时建立了基于DC-GRID的海上风电场系统模型。系统由永磁同步风机机组、离岸全桥直直变换器、岸端逆变器组成。各个永磁同步风电机组分别并联在高压大功率全桥DC-DC上,由升压后经过直流传输到岸端VSC之后,经逆变到适合交流电网传输的电压后并网。控制策略以及系统模型由MATLAB/SIMULINK仿真验证。

  7. Wind farm models and control strategies

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, Poul; Hansen, Anca D.; Iov, F.; Blaabjerg, F.; Donovan, M.H.

    2005-08-01

    This report describes models and control strategies for 3 different concepts of wind farms. Initially, the potential in improvement of grid integration, structural loads and energy production is investigated in a survey of opportunities. Then simulation models are described, including wind turbine models for a fixed speed wind turbine with active stall control and a variable speed wind turbine with doubly-fed induction generator. After that, the 3 wind farm concepts and control strategies are described. The 3 concepts are AC connected doubly fed turbines, AC connected active stall turbines and DC connected active stall turbines. Finally, some simulation examples and conclusions are presented. (au)

  8. An adaptive strategy for controlling chaotic system

    Institute of Scientific and Technical Information of China (English)

    曹一家; 张红先

    2003-01-01

    This paper presents an adaptive strategy for controlling chaotic systems. By employing the phase space reconstruction technique in nonlinear dynamical systems theory, the proposed strategy transforms the nonlinear system into canonical form, and employs a nonlinear observer to estimate the uncertainties and disturbances of the nonlinear system, and then establishes a state-error-like feedback law. The developed control scheme allows chaos control in spite of modeling errors and parametric variations. The effectiveness of the proposed approach has been demonstrated through its applications to two well-known chaotic systems : Duffing oscillator and Rǒssler chaos.

  9. Wind farm models and control strategies

    DEFF Research Database (Denmark)

    Sørensen, Poul Ejnar; Hansen, Anca Daniela; Iov, F.;

    2005-01-01

    models for a fixed speed wind turbine with active stall control and a variable speed wind turbine with doubly-fed induction generator. After that, the 3 wind farm concepts and control strategies are described.The 3 concepts are AC connected doubly fed turbines, AC connected active stall turbines and DC......This report describes models and control strategies for 3 different concepts of wind farms. Initially, the potential in improvement of grid integration, structural loads and energy production is investigated in a survey of opportunities. Then simulationmodels are described, including wind turbine...

  10. An adaptive strategy for controlling chaotic system.

    Science.gov (United States)

    Cao, Yi-Jia; Hang, Hong-Xian

    2003-01-01

    This paper presents an adaptive strategy for controlling chaotic systems. By employing the phase space reconstruction technique in nonlinear dynamical systems theory, the proposed strategy transforms the nonlinear system into canonical form, and employs a nonlinear observer to estimate the uncertainties and disturbances of the nonlinear system, and then establishes a state-error-like feedback law. The developed control scheme allows chaos control in spite of modeling errors and parametric variations. The effectiveness of the proposed approach has been demonstrated through its applications to two well-known chaotic systems: Duffing oscillator and Rössler chaos.

  11. An adaptive strategy for controlling chaotic system

    Institute of Scientific and Technical Information of China (English)

    曹一家; 张红先

    2003-01-01

    This paper presents an adaptive strategy for controlling chaotic systems. By employing the phase space reconstruction technique in nonlinear dynamical systems theory, the proposed strategy transforms the nonlinear system into canonical form, and employs a nonlinear observer to estimate the uncertainties and disturbances of the nonlinear system, and then establishes a state-error-like feedback law. The developed control scheme allows chaos control in spite of modeling errors and parametric variations. The effectiveness of the proposed approach has been demonstrated through its applications to two well-known chaotic systems: Duffing oscillator and Rossler chaos.

  12. Screening of pollution control and clean-up materials for river chemical spills using the multiple case-based reasoning method with a difference-driven revision strategy.

    Science.gov (United States)

    Liu, Rentao; Jiang, Jiping; Guo, Liang; Shi, Bin; Liu, Jie; Du, Zhaolin; Wang, Peng

    2016-06-01

    In-depth filtering of emergency disposal technology (EDT) and materials has been required in the process of environmental pollution emergency disposal. However, an urgent problem that must be solved is how to quickly and accurately select the most appropriate materials for treating a pollution event from the existing spill control and clean-up materials (SCCM). To meet this need, the following objectives were addressed in this study. First, the material base and a case base for environment pollution emergency disposal were established to build a foundation and provide material for SCCM screening. Second, the multiple case-based reasoning model method with a difference-driven revision strategy (DDRS-MCBR) was applied to improve the original dual case-based reasoning model method system, and screening and decision-making was performed for SCCM using this model. Third, an actual environmental pollution accident from 2012 was used as a case study to verify the material base, case base, and screening model. The results demonstrated that the DDRS-MCBR method was fast, efficient, and practical. The DDRS-MCBR method changes the passive situation in which the choice of SCCM screening depends only on the subjective experience of the decision maker and offers a new approach to screening SCCM.

  13. Discussion on base bid price controlling strategies in engineering tendering%谈工程招标中的标底控制策略

    Institute of Scientific and Technical Information of China (English)

    李学兵

    2012-01-01

    On the basis of introducing the definition and functions of base bid price, the paper comprehensively explores base bid price control- ling strategies from aspects of determining engineering project, compiling basic principles of base bid price, common compiling base bid price methods, improving rationality of base bid price, and common methods and points of determining base bid price and so on, with a view to guar- antee smooth operation of bidding and tendering work.%在介绍了标底的定义和分析了标底作用的基础上,从工程项目确定和编制标底的基本原则、编制工程项目标底的常用方法、提高工程项目标底合理性、确定工程项目标底的常用方法和要点等几个方面,全面探讨了工程招标中的标底控制策略,以期保障招投标工作的顺利进行。

  14. Knowledge Based Strategies for Knowledge Based Organizations

    OpenAIRE

    2012-01-01

    In the present, we can observe that a new economy is arising. It is an economy based on knowledge and ideas, in which the key factor for prosperity and for creation of the new jobs is the knowledge capitalization. Knowledge capitalization, intellectual capital, obtaining prosperity in the market economy imposes a new terminology, new managerial methods and techniques, new technologies and also new strategies. In other words, knowledge based economy, as a new type of economy; impose a new type...

  15. 基于消息优先级的 OppIoV拥塞控制策略%OppIoV Congestion Control Strategy Based on Message Priority

    Institute of Scientific and Technical Information of China (English)

    张龙; 曹文静; 于永利

    2015-01-01

    针对机会车联网的网络拥塞问题,提出了一种基于所传输消息优先级的车辆节点拥塞控制策略。当车辆节点存储空间不足而又需要存储新的消息时,该车辆节点内的所有消息按照其优先级由高到低排列,丢弃优先级最低的消息,直至有存储空间来接收新的消息。通过大量的仿真实验与传统的丢弃策略对比,该拥塞控制策略能显著提高消息的递交率,减小开销,并对网络拥塞状况有更好的自适应能力。%For network congestion of Opportunistic Internet of Vehicle ,a congestion control strategy of vehicle nodes based on the priority of the message transmission is proposed .When the storage space of vehicle nodes is insufficient and need to store the new messages ,all messages within the vehicle nodes according to their priority from high to low arrangement ,dropped the lowest priority message ,until there is storage space to receive a new message . Through a lot of simulation experiments and compared with traditional discarded strategies .The congestion control strategy can significantly increase the messages submitted rate ,reduce overhead ,and has better adaptive ability of network congestion situation .

  16. Experimental demonstration of a new model-based SCR control strategy for cleaner heavy-duty diesel engines

    NARCIS (Netherlands)

    Willems, F.P.T.; Cloudt, R.P.M.

    2011-01-01

    Selective catalytic reduction (SCR) is a promising diesel aftertreatment technology that enables low nitrogen oxides (NOx) tailpipe emissions with relatively low fuel consumption. Future emission legislation is pushing the boundaries for SCR control systems to achieve high NOx conversion within a ta

  17. A Distributed Control Strategy for Coordination of an Autonomous LVDC Microgrid Based on Power-Line Signalling

    DEFF Research Database (Denmark)

    Dragicevic, Tomislav; Guerrero, Josep M.; Vasquez, Juan Carlos

    2014-01-01

    In a MG, an energy management control is essential in order to handle the variety of prime movers which may include different types of renewable energy sources (RES) and energy storage systems (ESS). Specifically, the recharging process of secondary battery, the most prominent ESS, should be done...

  18. Assessing key safety concerns of a Wolbachia-based strategy to control dengue transmission by Aedes mosquitoes

    Directory of Open Access Journals (Sweden)

    Jean Popovici

    2010-12-01

    Full Text Available Mosquito-borne diseases such as dengue fever, chikungunya or malaria affect millions of people each year and control solutions are urgently needed. An international research program is currently being developed that relies on the introduction of the bacterial endosymbiont Wolbachia pipientis into Aedes aegypti to control dengue transmission. In order to prepare for open-field testing releases of Wolbachia-infected mosquitoes, an intensive social research and community engagement program was undertaken in Cairns, Northern Australia. The most common concern expressed by the diverse range of community members and stakeholders surveyed was the necessity of assuring the safety of the proposed approach for humans, animals and the environment. To address these concerns a series of safety experiments were undertaken. We report in this paper on the experimental data obtained, discuss the limitations of experimental risk assessment and focus on the necessity of including community concerns in scientific research.

  19. A Strategy for Quality Control of Menispermum dauricum DC Based on Cytotoxic Activity and HPLC Fingerprint Analysis

    OpenAIRE

    Liu, L. J.; J N Liu

    2016-01-01

    The rhizome of Menispermum dauricum DC known as a traditional Chinese medicine, with high content of alkaloids, has been found to possess antitumor activity. In this research, an attempt to correlate fingerprinting with bioactivity was made for quality control of M. dauricum. Firstly, the cytotoxicity of extracts from ten batches of samples against human breast MCF-7 cancer cells was estimated by [3-(4, 5-dimethylthiazole-2-yl)-2, 5-diphenyltetrazoliumbromide] assay. Then, cytotoxic activity-...

  20. Low Activity Waste Feed Process Control Strategy

    Energy Technology Data Exchange (ETDEWEB)

    STAEHR, T.W.

    2000-06-14

    The primary purpose of this document is to describe the overall process control strategy for monitoring and controlling the functions associated with the Phase 1B high-level waste feed delivery. This document provides the basis for process monitoring and control functions and requirements needed throughput the double-shell tank system during Phase 1 high-level waste feed delivery. This document is intended to be used by (1) the developers of the future Process Control Plan and (2) the developers of the monitoring and control system.

  1. 基于变结构模糊控制的MPPT控制策略%Control strategy on MPPT based on variable structure fuzzy control

    Institute of Scientific and Technical Information of China (English)

    袁晓玲; 范发靖; 周素梅

    2012-01-01

    As the high cost of photovoltaic cells and the low transformation efficiency is,in order to improve the efficiency of photovoltaic generation system, a Maximum Power Point: Tracking (MPPT) method bases on Incremental Conductance and Fuzzy control was improved. The method of asymmetrical output membership function and a variable structure Fuzzy control with PID was adopted, and response to the outside environmental changes rapidly and the photovoltaic cells MPP was tracked exactly,output vibration of MPP also decreased in this method.%为了充分提高光伏发电系统的效率,针对光伏电池成本高、转化效率低的问题,基于电导增量法和模糊控制技术,提出了一种最大功率点跟踪方法.该方法采用了非对称的输出隶属度函数和具有PID功能的变结构模糊控制,能快速响应外界环境变化,准确跟踪到光伏电池的最大功率点,且有效地减小了最大功率点处的输出波动.

  2. Energy control strategy for parallel hydrostatic transmission hybrid vehicles

    Institute of Scientific and Technical Information of China (English)

    SUN Hui; JIANG Ji-hai; WANG Xin

    2009-01-01

    Aimed at the relatively lower energy density and complicated coordinating operation between two power sources, a special energy control strategy is required to maximize the fuel saving potential. Then a new type of configuration for hydrostatic transmission hybrid vehicles (PHHV) and the selection criterion for impor-tant components are proposed. Based on the optimization of planet gear transmission ratio and the analysis of op-timal energy distribution for the proposed PHHV on a representative urban driving cycle, a fuzzy torque control strategy and a braking energy regeneration strategy are designed and developed to realize the real-time control of energy for the proposed PHHV. Simulation results demonstrate that the energy control strategy effectively im-proves the fuel economy of PHHV.

  3. Control Strategies for DFIG Wind Turbines Under Grid Fault

    DEFF Research Database (Denmark)

    Luna, Alvara; Rolan, A.; Medeiros, G.;

    2009-01-01

    The classical control techniques for regulating the active and reactive power delivery in doubly fed induction generators (DFIG), for wind power applications, are normally based on voltage oriented control (VOC) strategies. Among these algorithms, those that work in a synchronous reference frame...

  4. Comparison of Power Control Strategies for DFIG Wind Turbines

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Luna, A.; Rodríguez, P.;

    2008-01-01

    The classical control techniques for regulating the active and reactive power delivery in doubly fed induction generators (DFIG), for wind power applications, are normally based on voltage oriented control (VOC) strategies. Among these algorithms, those that work in a synchronous reference frame...

  5. Control Mechanism Strategies for Spin-Stabilized Projectiles

    Science.gov (United States)

    2008-09-01

    from more traditional smart weapons, thus warranting basic research into guidance and control strategies. Conventional methods include canards, fins...moment arms. AACC XNXN  . (1) 14 CG CP Nose Base Figure 13. Relationship between maneuver footprint and control axial location. XC CG MC

  6. Control and Protection Cooperation Strategy for Voltage Instability

    DEFF Research Database (Denmark)

    Liu, Zhou; Chen, Zhe; Sun, Haishun;

    2012-01-01

    Most cascaded blackouts are caused by unexpected backup relay operations due to low voltage or overload state caused by post fault load restoration dynamics. If such state can be sensed and adjusted appropriately prior to those relay actions, system stability might be sustained. This paper proposed...... a control and protection cooperation strategy to prevent post fault voltage instability. The multi-agent technology is applied for the strategy implementation; the criteria based on wide area measured apparent impedances are defined to choose the control strategy, such as tap changer adjusting or load...

  7. Development of a low-cost wireless controller for flexible sampling strategies based on real-time flow monitoring

    Science.gov (United States)

    Queloz, Pierre; Besuchet, Jonathan; Rao, P. Suresh C.; Rinaldo, Andrea

    2013-04-01

    Even if models are able to predict more and more accurately pollutant discharge in streams, surface water sampling remains a very common practice to monitor substance concentrations and loads in streams and to calibrate models. However, as this method is temporally and spatially punctual, monitoring a whole catchment requires multiple sampling sites with time-distributed samples. Instruments are expensive, and sample collection, on-site interventions and maintenance are costly and time-consuming, in particular if the experimental site is remote. Another issue is the estimation of the discharge loads of a pollutant, especially for non-chemostatic compounds; their hydrograph-related chemical dynamics may be miss-evaluated when a rapid storm occurs using a time-paced sampling strategy with large sampling intervals. Many manufacturers provide discharge gauges (pressure probes or ultra-sonic sensors) or other instruments (rain gauge, chemical probes, etc.) that can be coupled with automatic water samplers in order to program an event-paced sampling. However, automatic samplers usually provide limited programming options that may not meet the needs of the experimenter of a specific catchment. The concept presented here proposes to use a simple microcontroller board in order to determine the timing of the samples by sending electrical pulses to a conventional automatic sampler with input capability. The flow level is measured by a low-cost ultrasonic sensor and sent to the microcontroller, which will process the signal according to user and site-custom parameters. For example, a simple power-law recession model can be apply to approximate the duration of the recession period given the maximal discharge rate measured for a storm. The sample intervals can thereafter be set in order to distribute all the bottles available over the total recession duration. The microcontroller sends a pulse (grab sample query) to the sampler at every sample time calculated by the program. A

  8. A belief-based evolutionarily stable strategy.

    Science.gov (United States)

    Deng, Xinyang; Wang, Zhen; Liu, Qi; Deng, Yong; Mahadevan, Sankaran

    2014-11-21

    As an equilibrium refinement of the Nash equilibrium, evolutionarily stable strategy (ESS) is a key concept in evolutionary game theory and has attracted growing interest. An ESS can be either a pure strategy or a mixed strategy. Even though the randomness is allowed in mixed strategy, the selection probability of pure strategy in a mixed strategy may fluctuate due to the impact of many factors. The fluctuation can lead to more uncertainty. In this paper, such uncertainty involved in mixed strategy has been further taken into consideration: a belief strategy is proposed in terms of Dempster-Shafer evidence theory. Furthermore, based on the proposed belief strategy, a belief-based ESS has been developed. The belief strategy and belief-based ESS can reduce to the mixed strategy and mixed ESS, which provide more realistic and powerful tools to describe interactions among agents.

  9. Design of a Road Friendly SAS System for Heavy-Duty Vehicles Based on a Fuzzy-Hybrid-ADD and GH-Control Strategy

    Directory of Open Access Journals (Sweden)

    Jing Zhao

    2016-01-01

    Full Text Available Semiactive suspension (SAS system has been widely used for its outstanding performance in offering competent ride quality, road holding, and handling capacity. However, the road friendliness is also one of the crucial factors that should be attached in the design of the SAS system for heavy-duty vehicles. In this study, a fuzzy controlled hybrid-acceleration driven damper (ADD and ground hook- (GH- control strategy is proposed for SAS system of heavy-duty vehicles. Firstly, a quarter-vehicle model with SAS system is constructed. Then, aiming to improve the ride quality and road friendliness, a hybrid-ADD and GH-control strategy is proposed under the coordination of the fuzzy controller. Numerical results show that the ride quality and road friendliness of the SAS system with the proposed control strategy outperform those with traditional hybrid-sky hook and ground hook-control strategy. It is also verified that the proposed strategy is superior to the sole ADD approach and sole ground hook approach in improving the vehicle overall performance.

  10. Control strategy for Single-phase Transformerless Three-leg Unified Power Quality Conditioner Based on Space Vector Modulation

    DEFF Research Database (Denmark)

    Lu, Yong; Xiao, Guochun; Wang, Xiongfei

    2016-01-01

    The unified power quality conditioner (UPQC) is known as an effective compensation device to improve PQ for sensitive end-users. This paper investigates the operation and control of a single-phase three-leg UPQC (TL-UPQC), where a novel space vector modulation method is proposed for naturally...... solving the coupling problem introduced by the common switching leg. The modulation method is similar to the well-known space vector modulation widely used with three-phase voltage source converters, which thus brings extra flexibility to the TL-UPQC system. Two optimized modulation modes with either...... reduced switching loss or harmonic distortion are derived, evaluated, and discussed, in order to demonstrate the flexibility brought by the space vector modulated TL-UPQC. Simulations and experimental results are presented to verify the feasibility and effectiveness of the proposed space vector modulation...

  11. Abc-frame complex-coefficient filter and controller based current harmonic elimination strategy for three-phase grid connected inverter

    DEFF Research Database (Denmark)

    Guo, Xiaoqiang; Guerrero, Josep M.

    2016-01-01

    inverter. Different from the traditional method, our proposal utilizes the unique abc-frame complex-coefficient filter and controller to achieve the balanced, sinusoidal grid current. The main feature of the proposed method is simple and easy to implement without any frame transformation. The theoretical...... analysis and experimental test are presented. The experimental results verify the effectiveness of the proposed control strategy....

  12. Main Strategies for Autonomous Robotic Controller Design

    OpenAIRE

    Paterega, I.

    2011-01-01

    This review gives an overall introduction to the artificial evolution mechanism. It presents the main strategies for robotic controller design. It gives a review of the pertinent literature, focusing on approaches that use neural networks, evolutionary computing, and fuzzy logic. Various applications of artificial evolution in robotics are surveyed and classified.

  13. Malaria vector control: current and future strategies

    NARCIS (Netherlands)

    Takken, W.; Knols, B.G.J.

    2009-01-01

    The recently announced call for malaria eradication represents a new page in the history of this disease. This has been triggered by remarkable reductions in malaria resulting from combined application of effective drugs and vector control. However, this strategy is threatened by development of inse

  14. A unified control strategy for the active reduction of sound and vibration

    NARCIS (Netherlands)

    Doelman, N.J.

    1991-01-01

    The generalized minimum variance (GMV) control strategy is proposed as an effective strategy for active sound and vibration control systems. The GMV strategy is shown to unify well-known adaptive filtering approaches based on LMS-type algorithms and purely feedback strategies as used in other types

  15. 基于HMCD的仿人机器人单杠运动控制策略%HMCD-based dynamic motion control strategy of humanoid robot on a horizontal bar

    Institute of Scientific and Technical Information of China (English)

    陈雯柏; 高世杰; 吴细宝

    2012-01-01

    为完成仿人机器人单杠运动,分析了欠驱动单杠机器人Acrobot模型,并根据IHOG技术要求、实物机器人本体结构和自由度配置,提出了基于HMCD的控制策略.通过单杠视频捕捉获取人体运动数据,根据仿人机器人模型分析关键特征点、基本动作的运动数据得到的关键帧的关节角数据,经过运动学约束调整,采用插值方法生成能够应用于仿人机器人的运动轨迹.在MF-1型仿人机器人单杠实物平台上进行控制实验的成功,验证了该方法的有效性.%Aiming at the movement implementation of a humanoid robot on a horizontal bar, the control strategy based on HMCD (human motion capture data) is proposed in this paper. The Acrobot model, its physical structure, the degree of freedom and the technical requirements of International Humanoid-robot Olympic Games (IHOG) were analyzed for the robot on a horizontal bar. The key steps of this dynamic motion strategy are motion data capture through the video of humans motion on the horizontal bar, the key feature points'analysis of the humanoid robot model and the joint angles kinematic data match in the basic movements. After making the appropriate adjustments due to the kinematic constraints, an interpolation method was used to generate the motion trajectory of all the joints. The experimental results, based on MF-1 type humanoid robot on the horizontal bar indicate that the proposed method is feasible and effective.

  16. Research of vector control strategy of the Vienna rectifier based on SVPWM%基于SVPWM的Vienna整流器矢量控制策略的研究

    Institute of Scientific and Technical Information of China (English)

    张豪; 侯圣语

    2012-01-01

    According to the shortcomings of the tradional two-level rectifier and three-level rectifier, In the situation of the energy don't need double-way flow, Further research on the three-phase three-switch three-level Vienna rectifier in this paper; Based on the topology structure of this rectifier, analysis on its working principle, and based on the SVP-WM, A vector control strategy of the Vienna rectifier was put forward, which use dual closed loop with voltage outer loop and current inner loop; Finally, the vector control simulation model of Vienna rectifier was build, through the simulation analysis in Matlab environment, The results show that the Vienna rectifier has simple control and good dynamic performance and static performance.%针对传统两电平整流器和三电平整流器的不足,在能量不需要双向流动的应用场合,本文深入研究了一种三相三开关三电平Vienna整流器;基于该整流器的拓扑结构,分析了其基本工作原理,提出了一种基于SVPWM的Vienna整流器的电压外环、电流内环的双闭环矢量控制策略;最后搭建了Vienna整流器矢量控制仿真模型,通过Matlab环境下的仿真分析,证实了该整流器控制简单,具有良好的动态性能和静态性能.

  17. 基于软件优化的D-STATCOM新型控制策略%A novel control strategy based on software optimization for D-STATCOM

    Institute of Scientific and Technical Information of China (English)

    常鲜戎; 王辉云; 郭一杰; 杨永华

    2014-01-01

    控制延时会导致配电网静止同步补偿器(D-STATCOM)对谐波抑制和无功补偿的精度降低。为改善传统控制策略滞后时间长、补偿效果差的缺点,提出了一种基于软件优化的新型控制策略。通过对D-STATCOM补偿指令电流的特性进行分析,对软件流程进行相应调整,缩短了谐波和无功补偿指令电流的计算延时,使补偿滞后大大减少,谐波抑制和无功补偿的精度得到明显提高。该策略无需复杂算法,实现简单、有效。在Matlab/Simulink环境中进行了仿真分析,并且研制了一台容量为10 kVA的三相四线制D-STATCOM实验样机进行验证,结果证明了新型控制策略的正确性和可行性。%Control delay significantly affects the performance of distribution static synchronous compensator (D-STATCOM) in harmonic suppression and reactive power compensation. To overcome the drawback of the conventional control method, which has long compensation delay and low compensation accuracy, a novel control strategy based on software optimization is proposed. Software flow is adjusted based on the analysis of the reference compensation currents. It shortens the calculation delay of harmonics and reactive power compensation reference current, so compensation delay occurs less and compensation accuracy of harmonic suppression and reactive power compensation is improved. Results obtained by D-STATCOM simulations system built in Matlab/Simulink and prototype experiment of a 10 kVA three-phase four-wire D-STATCOM show the validity and feasibility of the proposed strategy.

  18. A semi-decentralized control strategy for urban traffic

    OpenAIRE

    Farhi, Nadir; Nguyen Van Phu, Cyril; AMIR, Mouna; Haj Salem, Habib; LEBACQUE, Jean Patrick

    2015-01-01

    EWGT - Euro Working Group on Transportation, Delft, PAYS-BAS, 14-/07/2015 - 16/07/2015; We present in this article a semi-decentralized approach for urban traffic control, based on the TUC (Traffic responsive Urban Control) strategy. We assume that the control is centralized as in the TUC strategy, but we introduce a contention time window inside the cycle time, where antagonistic stages alternate a priority rule. The priority rule is set by applying green colours for given stages and yellow ...

  19. Decoupling Control Strategy for Single Phase SPWM Parallel Inverters

    Institute of Scientific and Technical Information of China (English)

    Shun-Gang Xu; Jian-Ping Xu; Tai-Qiang Cao

    2009-01-01

    A decoupling control strategy of inverter parallel system is proposed based on the equivalent output impedance of single phase voltage source SPWM (sinusoidal pulse width modulation) inverter. The active power and reactive power are calculated in terms of output voltage and current of the inverter, and sent to the other inverters in the parallel system via controller area network (CAN) bus. By calculating and decoupling the circumfluence of the active power and reactive power, the inverters can share load current via the regulation of the reference-signal phase and amplitude. Experimental results of an 110V/2kVA inverter parallel system show the feasibility of the decoupling control strategy.

  20. Mesh refinement strategy for optimal control problems

    Science.gov (United States)

    Paiva, L. T.; Fontes, F. A. C. C.

    2013-10-01

    Direct methods are becoming the most used technique to solve nonlinear optimal control problems. Regular time meshes having equidistant spacing are frequently used. However, in some cases these meshes cannot cope accurately with nonlinear behavior. One way to improve the solution is to select a new mesh with a greater number of nodes. Another way, involves adaptive mesh refinement. In this case, the mesh nodes have non equidistant spacing which allow a non uniform nodes collocation. In the method presented in this paper, a time mesh refinement strategy based on the local error is developed. After computing a solution in a coarse mesh, the local error is evaluated, which gives information about the subintervals of time domain where refinement is needed. This procedure is repeated until the local error reaches a user-specified threshold. The technique is applied to solve the car-like vehicle problem aiming minimum consumption. The approach developed in this paper leads to results with greater accuracy and yet with lower overall computational time as compared to using a time meshes having equidistant spacing.

  1. A Distributed Control Strategy for an Isolated Residential DC Microgrid

    Directory of Open Access Journals (Sweden)

    Guiting Xue

    2012-09-01

    Full Text Available A low-voltage unipolar type dc microgrid , which includes photovoltaic (PV arrays, Fuel Cells (FCs, batteries and power electronic interfaces, is presented in this study. In order to provide the plug-and-play feature, a distributed control strategy based on Dc Bus Signaling (DBS is studied. According to the proposed control strategy, the operations of the dc microgrid are categorized into three modes: batteries charging/discharging, Constant Voltage (CV generation and FCs discharging. These three kinds of modes can be automatically switched by using DBS. Control methods of converters for different microsources are also addressed. Simulation results are provided to verify the effectiveness of the proposed control strategy.

  2. Design of a Road Friendly SAS System for Heavy-Duty Vehicles Based on a Fuzzy-Hybrid-ADD and GH-Control Strategy

    OpenAIRE

    Jing Zhao; Pak Kin Wong; Zhengchao Xie; Xinbo Ma; Caiyang Wei

    2016-01-01

    Semiactive suspension (SAS) system has been widely used for its outstanding performance in offering competent ride quality, road holding, and handling capacity. However, the road friendliness is also one of the crucial factors that should be attached in the design of the SAS system for heavy-duty vehicles. In this study, a fuzzy controlled hybrid-acceleration driven damper (ADD) and ground hook- (GH-) control strategy is proposed for SAS system of heavy-duty vehicles. Firstly, a quarter-vehic...

  3. The Robust Control Mixer Method for Reconfigurable Control Design By Using Model Matching Strategy

    DEFF Research Database (Denmark)

    Yang, Z.; Blanke, Mogens; Verhagen, M.

    2001-01-01

    This paper proposes a robust reconfigurable control synthesis method based on the combination of the control mixer method and robust H1 con- trol techniques through the model-matching strategy. The control mixer modules are extended from the conventional matrix-form into the LTI sys- tem form. By...

  4. Reading comprehension metacognitive strategies as a means for controlling behavior

    Directory of Open Access Journals (Sweden)

    Dinorah Aladina Caballero López

    2014-07-01

    Full Text Available Textual comprehension implies the use of various metacognitive strategies by the students when they have to face a text to be competent readers. That is why the objective of this article is to illustrate the application of metacognitive strategies in order to achieve an efficient textual comprehension, taking into account the self – regulation the student exerts over his own learning process. It is applied as the main method historical-logical studies based on a professional-researching systematic practice; at the same time observation is largely used. The main result is the introduction of metacognitive strategies in reading comprehension, which subsequently favor the self-control of personal behavior. The article is the result of a research project sponsored by the department of Special Education. Key words: reading comprehension, metacognitive strategies, behavior self-control.

  5. A NEW STOCHASTIC OPTIMAL CONTROL STRATEGY FOR HYSTERETIC MR DAMPERS

    Institute of Scientific and Technical Information of China (English)

    YingZuguang; NiYiqing; KoJanming

    2004-01-01

    A new stochastic optimal control strategy for randomly excited quasi-integrable Hamiltonian systems using magneto-theological (MR) dampers is proposed. The dynamic behavior of an MR damper is characterized by the Bouc-Wen hysteretic model. The control force produced by the MR damper is separated into a passive part incorporated in the uncontrolled system and a semi-active part to be determined. The system combining the Bouc-Wen hysteretic force is converted into an equivalent non-hysteretic nonlinear stochastic control system. Then Ito stochastic differential equations are derived from the equivalent system by using the stochastic averaging method. A dynamical programming equation for the controlled diffusion processes is established based on the stochastic dynamical programming principle. The non-clipping nonlinear optimal control law is obtained for a certain performance index by minimizing the dynamical programming equation. Finally, an example is given to illustrate the application and effectiveness of the proposed control strategy.

  6. Novel deadbeat power control strategy for grid connected systems

    Directory of Open Access Journals (Sweden)

    Yousry Atia

    2015-09-01

    Full Text Available This paper introduces a novel approach for power control of three phase voltage source inverter (VSI in grid connected distribution generation system. In this approach, the control of active and reactive power is based on deadbeat control strategy. First, the difference between the reference and actual currents are introduced in different approach. Then current to power substitutions are carried out to obtain direct relationship between the required inverter voltage and instantaneous power errors. There is no need for coordinate transformation or PLL, where the required inverter voltage vector calculations carried out in α–β stationary reference frame. The proposed technique introduces two cross coupling components in the control function. Including these two components, the controller can achieve nearly zero steady-state tracking error of the controlled variables. To obtain fixed switching frequency operations, space vector modulation (SVM is used to synthesize the required inverter voltage vector and to generate the switching pulses for the VSI. The proposed strategy has the simplicity of the direct power control (DPC technique and doesn’t require any current control loops. The proposed strategy is experimentally implemented using fixed-point microcontroller. Simulation and experimental results are presented to confirm the superiority of the proposed strategy.

  7. A New Scheduling Strategy of Elevator Group Control Based on Pdf Control%一种新的基于PDF控制的电梯群控调度策略

    Institute of Scientific and Technical Information of China (English)

    吴贵芳; 吴胜

    2012-01-01

    For the nondeterminacy of transportation characteristics in the elevator group control scheduling process, a elevator group control system model is established including the shortest waiting time, the shortest syndrome ladder by ladder time and at least energy consumption, and a scheduling strategy of elevator group control based on PDF control is presented which can content the requirement of a adapt elevator group control performance. The algorithm was improved to achieve better dispatching result, and simulation experiment finally. The simulation results show that this method compared with other algorithms in elevator group control scheduling performance and traffic model's adaptability has greatly improved.%针对电梯群控调度过程中交通特性的不确定性,建立了包括最短候梯时间,最短乘梯时间和最少能耗的电梯群控系统的模型,提出了一种适应电梯群控性能需求的伪微分反馈控制算法,并对算法进行改进来达到更好的调度效果,最后进行仿真实验.仿真结果表明该方法与其他算法相比在电梯群控调度性能和交通模式的适应性方面有较大的改善.

  8. 40 CFR 52.2332 - Control Strategy: Ozone.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control Strategy: Ozone. 52.2332...: Ozone. Determinations—EPA is determining that, as of July 18, 1995, the Salt Lake and Davis Counties ozone nonattainment area has attained the ozone standard based on air quality monitoring data from...

  9. 40 CFR 52.1174 - Control strategy: Ozone.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Ozone. 52.1174...: Ozone. (a) Part D—Conditional Approval—Michigan Rules 336.1603 and 336.1606 are approved provided that... Resources submitted a revision to the ozone State Implementation Plan (SIP) for the 1990 base year...

  10. Some thoughts on separation control strategies

    Indian Academy of Sciences (India)

    P R Viswanath

    2007-02-01

    Separation control has received considerable emphasis in literature both owing to fundamental flow physics and technological applications. Flow separation generally leads to increased energy losses, instability and so on, and its control is essential to improve aerodynamic performance. Here a brief review is presented of three broad strategies for separation control: these include methods that involve energization of the boundary layer upstream of separation, those that involve altering the bubble flow or dead air zone, and those that may influence the shear layer reattachment directly. Examples from recent research in our laboratories are reviewed and it is suggested that direct manipulation of the reattachment process could lead to effective control/management.

  11. A new balancing three level three dimensional space vector modulation strategy for three level neutral point clamped four leg inverter based shunt active power filter controlling by nonlinear back stepping controllers.

    Science.gov (United States)

    Chebabhi, Ali; Fellah, Mohammed Karim; Kessal, Abdelhalim; Benkhoris, Mohamed F

    2016-07-01

    In this paper is proposed a new balancing three-level three dimensional space vector modulation (B3L-3DSVM) strategy which uses a redundant voltage vectors to realize precise control and high-performance for a three phase three-level four-leg neutral point clamped (NPC) inverter based Shunt Active Power Filter (SAPF) for eliminate the source currents harmonics, reduce the magnitude of neutral wire current (eliminate the zero-sequence current produced by single-phase nonlinear loads), and to compensate the reactive power in the three-phase four-wire electrical networks. This strategy is proposed in order to gate switching pulses generation, dc bus voltage capacitors balancing (conserve equal voltage of the two dc bus capacitors), and to switching frequency reduced and fixed of inverter switches in same times. A Nonlinear Back Stepping Controllers (NBSC) are used for regulated the dc bus voltage capacitors and the SAPF injected currents to robustness, stabilizing the system and to improve the response and to eliminate the overshoot and undershoot of traditional PI (Proportional-Integral). Conventional three-level three dimensional space vector modulation (C3L-3DSVM) and B3L-3DSVM are calculated and compared in terms of error between the two dc bus voltage capacitors, SAPF output voltages and THDv, THDi of source currents, magnitude of source neutral wire current, and the reactive power compensation under unbalanced single phase nonlinear loads. The success, robustness, and the effectiveness of the proposed control strategies are demonstrated through simulation using Sim Power Systems and S-Function of MATLAB/SIMULINK.

  12. A Radiation Control Strategy for Counter-Sorting of Fire-Control Radar Network Based on Tracking Requirement%基于跟踪任务需求的火控雷达网抗分选控制策略

    Institute of Scientific and Technical Information of China (English)

    陈兴凯; 封吉平; 韩壮志; 王学磊; 李成玉

    2014-01-01

    针对火控雷达信号极易被敌方侦察系统分选识别的问题,提出一种基于跟踪任务需求的抗分选控制策略。首先通过跟踪精度描述了火控雷达对目标的跟踪任务需求;然后将间歇开机与雷达组网相结合,在满足门限精度的条件下,对火控雷达网内的雷达进行轮换开机控制;最后对侦察系统的信号分选部分进行了仿真建模,通过分选成功率验证控制策略的有效性。结果表明,该策略在保证跟踪需求的前提下,使网内雷达信号的抗分选性能得到了提高。%The fire-control radar's signal is easily to be sorted and identified by the enemy reconnaissance system .Aiming at this problem,a radiation control strategy is proposed to improve the counter-sorting performance based on tracking requirement .Firstly,the tracking requirement of the fire-control radar to a target is described as the tracking accuracy .Then intermittent work is combined with radar network,and radars of the network are controlled through work rotation on the condition that the threshold tracking accuracy is kept .Finally,the simulation model of reconnaissance system's signal sorting is established,and the effectiveness of control strategy is verified .The results show that,with the radiation control strategy,the counter-sorting performance of the fire-control radars in the network is increased while keeping target tracking .

  13. Controlling strategy of dormant Mycobacterium tuberculosis

    Institute of Scientific and Technical Information of China (English)

    Gan Yiling; Guo Shuliang

    2014-01-01

    Objective This study aimed to review the available literatures on control of latent tuberculosis (TB) infection and propose a new control strategy to shorten the course of TB chemotherapy.Data sources The data used in this review were mainly obtained from articles listed in PubMed.The search terms were "therapy (treatment) of tuberculosis," "therapy (treatment) of latent TB infection," and "vaccine of TB."Study selection Articles regarding treatment and vaccine of TB were selected and reviewed.Results The most crucial reason causing the prolonged course of TB chemotherapy is the dormant state of Mycobacterium tuberculosis (M.tuberculosis).Nevertheless,there are,to date,no effective drugs that can directly kill the dormant cells of M.tuberculosis in clinical therapy.In accordance with the growth cycle of dormant M.tuberculosis in the body,the methods for controlling dormant M.tuberculosis include direct killing with drugs,prevention of dormant M.tuberculosis resuscitation with vaccines,and resuscitating dormant M.tuberculosis with preparations or drugs and then thoroughly killing these resuscitated M.tuberculosis by using anti-TB therapy.Conclusions The comprehensive analysis of the above three methods suggests that the drugs directly killing dormant cells are in clinical trials,TMC207 is the most beneficial for controlling TB.Because the side effect of vaccines is less and their action period is long,prevention of dormant cells resuscitation with vaccines is promising.The last control method makes it probable that when a huge number of active cells of M.tuberculosis have been killed and eradicated after 1-month short chemotherapy,only a strong short-term subsequent chemotherapy can completely kill and eradicate the remaining M.tuberculosis.This control strategy is expected to significantly shorten the course of TB chemotherapy and bring a new change and breakthrough in TB treatment.

  14. Chaos Control on a Duopoly Game with Homogeneous Strategy

    Directory of Open Access Journals (Sweden)

    Manying Bai

    2016-01-01

    Full Text Available We study the dynamics of a nonlinear discrete-time duopoly game, where the players have homogenous knowledge on the market demand and decide their outputs based on adaptive expectation. The Nash equilibrium and its local stability are investigated. The numerical simulation results show that the model may exhibit chaotic phenomena. Quasiperiodicity is also found by setting the parameters at specific values. The system can be stabilized to a stable state by using delayed feedback control method. The discussion of control strategy shows that the effect of both firms taking control method is better than that of single firm taking control method.

  15. 基于投切门限值的无功补偿控制策略研究%Study on control strategy for var compensation based on capacitor-switching threshold

    Institute of Scientific and Technical Information of China (English)

    王腾飞

    2015-01-01

    Thyristor switched capacitor (TSC) is used more and more widely in var compensation device in our country, the control strategy of nine-zone diagram is often used, the strategy will produce "switching oscillation" phenomenon in some control areas. Therefore, this paper proposes a control strategy based on the capacitor-switching threshold, in order to test the feasibility of the strategy, simulation model based on the strategy for TSC var compensation is created, the results show that this strategy can not only overcome strategy of nine-zone diagram, but also can improve the response speed and precision accuracy of capacitor-switching, and can completely meet the requirements of control strategy for var compensation.%晶闸管投切电容器(TSC)是我国目前较为常用的无功补偿装置,其控制规则往往采用九域图控制,该策略在某些控制区域会产生“投切振荡”的现象。为此,本文提出了一种基于投切门限值的控制策略,为了检验所提出控制策略的可行性,建立了基于该策略的TSC无功补偿仿真模型,仿真结果表明该策略不仅能够克服九域图控制的不足,而且可以提高电容器组投切的响应速度和无功补偿精度,完全能满足无功补偿控制装置的策略需要。

  16. Model predictive control power management strategies for HEVs: A review

    Science.gov (United States)

    Huang, Yanjun; Wang, Hong; Khajepour, Amir; He, Hongwen; Ji, Jie

    2017-02-01

    This paper presents a comprehensive review of power management strategy (PMS) utilized in hybrid electric vehicles (HEVs) with an emphasis on model predictive control (MPC) based strategies for the first time. Research on MPC-based power management systems for HEVs has intensified recently due to its many inherent merits. The categories of the existing PMSs are identified from the latest literature, and a brief study of each type is conducted. Then, the MPC approach is introduced and its advantages are discussed. Based on the acquisition method of driver behavior used for state prediction and the dynamic model used, the MPC is classified and elaborated. Factors that affect the performance of the MPC are put forward, including prediction accuracy, design parameters, and solvers. Finally, several important issues in the application of MPC-based power management strategies and latest developing trends are discussed. This paper not only provides a comprehensive analysis of MPC-based power management strategies for HEVs but also puts forward the future and emphasis of future study, which will promote the development of energy management controller with high performance and low cost for HEVs.

  17. Hierarchical Control Strategy for the Cooperative Braking System of Electric Vehicle.

    Science.gov (United States)

    Peng, Jiankun; He, Hongwen; Liu, Wei; Guo, Hongqiang

    2015-01-01

    This paper provides a hierarchical control strategy for cooperative braking system of an electric vehicle with separated driven axles. Two layers are defined: the top layer is used to optimize the braking stability based on two sliding mode control strategies, namely, the interaxle control mode and signal-axle control strategies; the interaxle control strategy generates the ideal braking force distribution in general braking condition, and the single-axle control strategy can ensure braking safety in emergency braking condition; the bottom layer is used to maximize the regenerative braking energy recovery efficiency with a reallocated braking torque strategy; the reallocated braking torque strategy can recovery braking energy as much as possible in the premise of meeting battery charging power. The simulation results show that the proposed hierarchical control strategy is reasonable and can adapt to different typical road surfaces and load cases; the vehicle braking stability and safety can be guaranteed; furthermore, the regenerative braking energy recovery efficiency can be improved.

  18. Nonlinear Control Strategies for Bioprocesses: Sliding Mode Control versus Vibrational Control

    OpenAIRE

    Selisteanu, Dan; Petre, Emil; Popescu, Dorin; Bobasu, Eugen

    2008-01-01

    In this work, two nonlinear high-frequency control strategies for bioprocesses are proposed: a feedback sliding mode control law and a vibrational control strategy. In order to implement these strategies, a prototype bioprocess that is carried out in a Continuous Stirred Tank Bioreactor was considered. First, a discontinuous feedback law was designed using the exact linearization and by imposing a SMC that stabilizes the output of the bioprocess. When some state variables used in the control ...

  19. Comparison of different control strategies on FMD in Denmark

    DEFF Research Database (Denmark)

    Boklund, Anette; Hisham Beshara Halasa, Tariq; Christiansen, Lasse Engbo

    2012-01-01

    in duration and size of epidemics are large, and if epidemics are small, extra control measures may not always be necessary. Comparing depopulation to suppressive and protective vaccination shows that from an epidemiologic point of view, vaccination will be beneficial. However, comparing the economy......The purpose of this study was to compare different control strategies that could be used in Denmark during an outbreak of FMD, based on epidemiological, ethical and economic parameters. Nearly a hundred different control strategies and more than 30 sensitivity analyses were run, changing between...... to extract the essence of the results. All results will be presented in the final project report, which will be available on request to the authors. Comparing epidemiological outputs showed that extra control measures will always reduce the average duration and size of an epidemic. However, the variations...

  20. Persistent organic pollutants control strategy in China

    Institute of Scientific and Technical Information of China (English)

    SHI Ya-juan; LU Yong-long; ZHANG Hong; WANG Tie-yu; XING Ying

    2005-01-01

    The development of Persistent Organic Pollutants(POPs) control policy in China in the context of international concerns on POPs was reviewed. The aspects of the Chinese POPs control strategies were analyzed, and compared with those of developed counterparts (e.g. US, EU, Japan). Currently, while the legal framework on POPs management, which complies with international guidelines has been established, it should be improved in the areas of special POPs management, risk assessment, the precautionary principle, lifecycle management and technical support capacity. The analysis of Chinese POPs policy and suggestions for strengthening the sciencebased decision making capacity are not only useful for Chinese decision-makers, but also a case study for developing world and make a great contribution for the global elimination of POPs to make a toxic-free future.

  1. Novel strategies for control of fermentation processes

    DEFF Research Database (Denmark)

    Mears, Lisa

    (2012). This model describes the fungal processes operated in the fermentation pilot plant at Novozymes A/S. This model is investigated using uncertainty analysis methods in order to as-sess the applicability to control applications. A mechanistic model approach is desirable, as it is a predictive....... This provides a prediction of the future trajectory of the process, so that it is possible to guide the system to the desired target mass. The control strategy is applied on-line at 550L scale in the Novozymes A/S fermentation pilot plant, and the method is challenged with four different sets of process...... to highly optimised industrial host strains. The focus of this project is instead on en-gineering of the process. The question to be answered in this thesis is, given a highly optimised industrial host strain, how can we operate the fermentation process in order to maximise the productivity of the system...

  2. Control Strategy Scenarios for the Alien Lionfish Pterois volitans in Chinchorro Bank (Mexican Caribbean): Based on Semi-Quantitative Loop Analysis

    Science.gov (United States)

    Ortiz, Marco; Rodriguez-Zaragoza, Fabián; Hermosillo-Nuñez, Brenda; Jordán, Ferenc

    2015-01-01

    Ecological and eco-social network models were constructed with different levels of complexity in order to represent and evaluate management strategies for controlling the alien species Pterois volitans in Chinchorro bank (Mexican Caribbean). Levins´s loop analysis was used as a methodological framework for assessing the local stability (considered as a component of sustainability) of the modeled management interventions represented by various scenarios. The results provided by models of different complexity (models 1 through 4) showed that a reduction of coral species cover would drive the system to unstable states. In the absence of the alien lionfish, the simultaneous fishing of large benthic epifaunal species, adult herbivorous fish and adult carnivorous fish could be sustainable only if the coral species present high levels of cover (models 2 and 3). Once the lionfish is added to the simulations (models 4 and 5), the analysis suggests that although the exploitation or removal of lionfish from shallow waters may be locally stable, it remains necessary to implement additional and concurrent human interventions that increase the holistic sustainability of the control strategy. The supplementary interventions would require the implementation of programs for: (1) the restoration of corals for increasing their cover, (2) the exploitation or removal of lionfish from deeper waters (decreasing the chance of source/sink meta-population dynamics) and (3) the implementation of bans and re-stocking programs for carnivorous fishes (such as grouper) that increase the predation and competition pressure on lionfish (i.e. biological control). An effective control management for the alien lionfish at Chinchorro bank should not be optimized for a single action plan: instead, we should investigate the concurrent implementation of multiple strategies. PMID:26114745

  3. Analysis of Control Strategies for Aircraft Flight Upset Recovery

    Science.gov (United States)

    Crespo, Luis G.; Kenny, Sean P.; Cox, David E.; Muri, Daniel G.

    2012-01-01

    This paper proposes a framework for studying the ability of a control strategy, consisting of a control law and a command law, to recover an aircraft from ight conditions that may extend beyond the normal ight envelope. This study was carried out (i) by evaluating time responses of particular ight upsets, (ii) by evaluating local stability over an equilibrium manifold that included stall, and (iii) by bounding the set in the state space from where the vehicle can be safely own to wings-level ight. These states comprise what will be called the safely recoverable ight envelope (SRFE), which is a set containing the aircraft states from where a control strategy can safely stabilize the aircraft. By safe recovery it is implied that the tran- sient response stays between prescribed limits before converging to a steady horizontal ight. The calculation of the SRFE bounds yields the worst-case initial state corresponding to each control strategy. This information is used to compare alternative recovery strategies, determine their strengths and limitations, and identify the most e ective strategy. In regard to the control law, the authors developed feedback feedforward laws based on the gain scheduling of multivariable controllers. In regard to the command law, which is the mechanism governing the exogenous signals driving the feed- forward component of the controller, we developed laws with a feedback structure that combines local stability and transient response considera- tions. The upset recovery of the Generic Transport Model, a sub-scale twin-engine jet vehicle developed by NASA Langley Research Center, is used as a case study.

  4. Robust antisynchronization of chaos using sliding mode control strategy

    Indian Academy of Sciences (India)

    Amit Mondal; Mitul Islam; Nurul Islam

    2015-01-01

    The paper proposes a sliding mode control strategy-based scheme for achieving anti-synchronization between two coupled non-linear chaotic systems. The method works irrespective of whether the systems under consideration possess or lack inverse symmetry. Using a linear sliding surface, a sliding mode control input and a non-linear coupling function are designed that synchronizes the systems antiphase. Finite-time convergence of the method is established. The controller is also robust to all forms of bounded perturbations and this robustness can be easily achieved by tuning of a single controller parameter and introduction of a control vector. The controller is also made chattering-free by producing a continuous analogue of the discontinuous control input. The effectiveness of the method is established by implementing it to antisynchronize chaotic Sprott systems and Rossler systems. The results are also verified through numerical simulation work.

  5. Nosocomial infections and their control strategies

    Institute of Scientific and Technical Information of China (English)

    Hassan Ahmed Khan; Aftab Ahmad; Riffat Mehboob

    2015-01-01

    Nosocomial infections are also known as hospital-acquired/associated infections. National Healthcare Safety Network along with Centers for Disease Control for surveillance has classified nosocomial infection sites into 13 types with 50 infection sites, which are specific on the basis of biological and clinical criteria. The agents that are usually involved in hospital-acquired infections include Streptococcus spp., Acinetobacter spp., enterococci, Pseudomonas aeruginosa, coagulase-negative staphylococci, Staphylococcus aureus, Bacillus cereus, Legionella and Enterobacteriaceae family members, namely, Proteus mirablis, Klebsiella pneumonia, Escherichia coli, Serratia marcescens. Nosocomial pathogens can be transmitted through person to person, environment or contaminated water and food, infected individuals, contaminated healthcare personnel’s skin or contact via shared items and surfaces. Mainly, multi-drug-resistant nosocomial organisms include methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, Pseudomonas aeruginosa and Klebsiella pneumonia, whereas Clostridium dififcile shows natural resistance. Excessive and improper use of broad-spectrum antibiotics, especially in healthcare settings, is elevating nosocomial infections, which not only becomes a big health care problem but also causes great economic and production loss in the community. Nosocomial infections can be controlled by measuring and comparing the infection rates within healthcare settings and sticking to the best healthcare practices. Centers for Disease Control and Prevention provides the methodology for surveillance of nosocomial infections along with investigation of major outbreaks. By means of this surveillance, hospitals can devise a strategy comprising of infection control practices.

  6. Nosocomial infections and their control strategies

    Institute of Scientific and Technical Information of China (English)

    Hassan; Ahmed; Khan; Aftab; Ahmad; Riffat; Mehboob

    2015-01-01

    Nosocomial infections are also known as hospital-acquired/associated infections. National Healthcare Safety Network along with Centers for Disease Control for surveillance has classified nosocomial infection sites into 13 types with 50 infection sites, which are specific on the basis of biological and clinical criteria. The agents that are usually involved in hospitalacquired infections include Streptococcus spp., Acinetobacter spp., enterococci, Pseudomonas aeruginosa, coagulase-negative staphylococci, Staphylococcus aureus, Bacillus cereus, Legionella and Enterobacteriaceae family members, namely, Proteus mirablis, Klebsiella pneumonia, Escherichia coli, Serratia marcescens. Nosocomial pathogens can be transmitted through person to person, environment or contaminated water and food, infected individuals, contaminated healthcare personnel’s skin or contact via shared items and surfaces. Mainly, multi-drug-resistant nosocomial organisms include methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, Pseudomonas aeruginosa and Klebsiella pneumonia, whereas Clostridium difficile shows natural resistance. Excessive and improper use of broadspectrum antibiotics, especially in healthcare settings, is elevating nosocomial infections, which not only becomes a big health care problem but also causes great economic and production loss in the community. Nosocomial infections can be controlled by measuring and comparing the infection rates within healthcare settings and sticking to the best healthcare practices. Centers for Disease Control and Prevention provides the methodology for surveillance of nosocomial infections along with investigation of major outbreaks. By means of this surveillance, hospitals can devise a strategy comprising of infection control practices.

  7. Nosocomial infections and their control strategies

    Directory of Open Access Journals (Sweden)

    Hassan Ahmed Khan

    2015-07-01

    Full Text Available Nosocomial infections are also known as hospital-acquired/associated infections. National Healthcare Safety Network along with Centers for Disease Control for surveillance has classified nosocomial infection sites into 13 types with 50 infection sites, which are specific on the basis of biological and clinical criteria. The agents that are usually involved in hospital-acquired infections include Streptococcus spp., Acinetobacter spp., enterococci, Pseudomonas aeruginosa, coagulase-negative staphylococci, Staphylococcus aureus, Bacillus cereus, Legionella and Enterobacteriaceae family members, namely, Proteus mirablis, Klebsiella pneumonia, Escherichia coli, Serratia marcescens. Nosocomial pathogens can be transmitted through person to person, environment or contaminated water and food, infected individuals, contaminated healthcare personnel's skin or contact via shared items and surfaces. Mainly, multi-drug-resistant nosocomial organisms include methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, Pseudomonas aeruginosa and Klebsiella pneumonia, whereas Clostridium difficile shows natural resistance. Excessive and improper use of broad-spectrum antibiotics, especially in healthcare settings, is elevating nosocomial infections, which not only becomes a big health care problem but also causes great economic and production loss in the community. Nosocomial infections can be controlled by measuring and comparing the infection rates within healthcare settings and sticking to the best healthcare practices. Centers for Disease Control and Prevention provides the methodology for surveillance of nosocomial infections along with investigation of major outbreaks. By means of this surveillance, hospitals can devise a strategy comprising of infection control practices.

  8. Intelligent Control Strategy for Dynamic Zero-Energy-Facades

    DEFF Research Database (Denmark)

    Winther, Frederik Vildbrad; Heiselberg, Per; Jensen, Rasmus Lund

    2016-01-01

    control strategies and their potential when applied in different climatic locations. The control strategies are furthermore tested in full scale at a test facility at Aalborg University in order to test the performance of the control strategies in relation to the thermal indoor climate through use...

  9. Economic analysis of HPAI control in the Netherlands II: comparison of control strategies.

    Science.gov (United States)

    Longworth, N; Mourits, M C M; Saatkamp, H W

    2014-06-01

    A combined epidemiological-economic modelling approach was used to analyse strategies for highly pathogenic avian influenza (HPAI) control for the Netherlands. The modelling framework used was InterSpread Plus (ISP), a spatially based, stochastic and dynamic simulation model. A total of eight control strategies were analysed, including pre-emptive depopulation and vaccination strategies. The analysis was carried out for three different regions in the Netherlands: high-, medium- and low-density areas (HDA, MDA and LDA, respectively). The analysis included the veterinary impact (e.g. number of infected premises and duration), but was particularly focused on the impact on direct costs (DC) and direct consequential costs. The efficient set of control strategies for HDA and MDA included strategies based on either pre-emptive depopulation only or combined vaccination and pre-emptive depopulation: D2 (pre-emptive depopulation within a radius of 2 km), RV3 + D1 (ring vaccination within a radius of 3 km and additional pre-emptive depopulation within a radius of 1 km) and PV + D1 (preventive vaccination in non-affected HDAs and pre-emptive depopulation within a radius of 1 km in the affected HDA). Although control solely based on depopulation in most cases showed to be effective for LDA, pre-emptive depopulation showed to have an additional advantage in these areas, that is, prevention of 'virus jumps' to other areas. The pros and cons of the efficient control strategies were discussed, for example, public perception and risk of export restrictions. It was concluded that for the Netherlands control of HPAI preferably should be carried out using strategies including pre-emptive depopulation with or without vaccination. Particularly, the short- and long-term implications on export, that is, indirect consequential costs (ICC) and aftermath costs of these strategies, should be analysed further.

  10. Temperature control strategy for a seal fatigue tester

    Directory of Open Access Journals (Sweden)

    M. Związek

    2008-08-01

    Full Text Available Purpose: The aim of the paper is optimization of a control strategy used in a seal fatigue tester.Design/methodology/approach: Analytical approach has been applied to get an understanding of a heat exchange process. It is required to optimize the control process algorithm.Findings: The initial control algorithm has been improved regarding numerous tests under different operating conditions. The final version of the control program allows to maintain the temperature according to the on-off strategy minimizing the temperature oscillations and potential overshoots.Research limitations/implications: It should be considered a new control strategy based on PID controller.Practical implications: The major component of the tester is the heat exchanger. It consists of a tube and embedded pipe circuit feeding with the external heating or cooling medium. The tube is a cylindrical housing where the seals are assembled at both sides. Two main pumps circulate the medium at a specified flow rate and pressure. The temperature is maintained to hold it almost constant during heating and cooling phases. Two thermocouples are placed close to the seals, and the one in the middle of the heat exchanger tube. The tester is equipped with a control system consisting of a PLC controller and LabView data acquisition application. It is possible to control the device remotely through LAN/WAN networks. The LabView application communicates with the controller via software with the use of PPI (Point-To-Point Interface protocol. A new control algorithm has allowed to perform tests according to testing specification without significant overshoots.Originality/value: On-off control algorithm has been proposed for a combined heating-cooling installation rarely using in the industrial solutions.

  11. 基于ExtendSim的自适应CONWIP控制策略研究%Research on the Control Strategy of Adaptive CONWIP Based on ExtendSim

    Institute of Scientific and Technical Information of China (English)

    王艳红; 赵新

    2016-01-01

    在多产品多阶段系统,需求的产生和服务时间是随机的,为了控制这类系统,针对已有的推式(Push)和拉式(Pull)生产控制策略使用的局限性,提出带有自适应看板和独立需求信息的拉式自适应定量在制品控制策略. 并以示例通过建立ExtendSim仿真模型说明提出策略的可行性,能够应对生产过程中的多类波动.%In multi-product and multi-phase system, the production and service time of the demand is random, in order to control the system, aim at the limitations of existing Push and Pull type production control strategies are used, presents with adaptive Kanban and independent information of demand pull type adaptive CONWIP control strategy.And an example is presented to illustrate the feasibility of the proposed method and can deal with the multi class fluctuations in the production process.

  12. Food Security Strategy Based on Computer Innovation

    OpenAIRE

    Ruihui Mu

    2015-01-01

    Case analysis to identify innovative strategies for food security occurred in the Oriental Hotel, voluntarily implement food safety control. Food security strategy investigation and the reasons for their use of multiple data sources, including accommodation and catering industry to implement and document interviews with key decision makers in the hotel performed to observe the business environment were examined. This finding suggests that addressing food security, not only is the food control...

  13. Control Strategy Research of Buck-Boost Matrix Converter Based on Fuzzy PI Control%基于模糊PI控制的Buck-Boost矩阵变换器控制策略研究

    Institute of Scientific and Technical Information of China (English)

    陈琪; 李旋

    2013-01-01

    针对一种具有优良电气特性的新型Buck-Boost矩阵变换器(BBMC)采用基于模糊PI的双闭环控制策略进行控制。阐述了该变换器的基本原理,研究了基于模糊PI的双闭环控制的具体设计方法。并采用MATLAB对其控制效果进行了仿真验证。结果表明:当BBMC输入侧电压发生突变时,模糊控制器能有效调节PI参数,使输出电压有效的跟随输入电压的变化而变化,从而系统迅速达到稳定。%According to a new Buck-Boost matrix converter (BBMC) having excellent electrical performance,uses the double closed loop control strategy based on fuzzy PI. This paper expounds the basic principle of the converter, studies the design method of double closed loop control based on fuzzy PI, and uses the MATLAB for the simulation of the control effect. The results show that, when the BBMC input voltage change, the fuzzy controller can effectively adjust the PI parameters, making the change of the output voltage effectively follow the change of the input voltage, thus the system rapidly reaches stable.

  14. Food Security Strategy Based on Computer Innovation

    Directory of Open Access Journals (Sweden)

    Ruihui Mu

    2015-04-01

    Full Text Available Case analysis to identify innovative strategies for food security occurred in the Oriental Hotel, voluntarily implement food safety control. Food security strategy investigation and the reasons for their use of multiple data sources, including accommodation and catering industry to implement and document interviews with key decision makers in the hotel performed to observe the business environment were examined. This finding suggests that addressing food security, not only is the food control strategy, when the issue of marketing and business strategy is very important. The results of this study also demonstrated the relationship between reward and food security strategies. Interview analysis showed that the attitude of senior management in the hotel's food security policy, the company's ability to significantly dependent on the corporate image.

  15. Chemical Biology Strategies for Biofilm Control.

    Science.gov (United States)

    Yang, Liang; Givskov, Michael

    2015-08-01

    Microbes live as densely populated multicellular surface-attached biofilm communities embedded in self-generated, extracellular polymeric substances (EPSs). EPSs serve as a scaffold for cross-linking biofilm cells and support development of biofilm architecture and functions. Biofilms can have a clear negative impact on humans, where biofilms are a common denominator in many chronic diseases in which they prime development of destructive inflammatory conditions and the failure of our immune system to efficiently cope with them. Our current assortment of antimicrobial agents cannot efficiently eradicate biofilms. For industrial applications, the removal of biofilms within production machinery in the paper and hygienic food packaging industry, cooling water circuits, and drinking water manufacturing systems can be critical for the safety and efficacy of those processes. Biofilm formation is a dynamic process that involves microbial cell migration, cell-to-cell signaling and interactions, EPS synthesis, and cell-EPS interactions. Recent progress of fundamental biofilm research has shed light on novel chemical biology strategies for biofilm control. In this article, chemical biology strategies targeting the bacterial intercellular and intracellular signaling pathways will be discussed.

  16. Designing a sustainable strategy for malaria control?

    Directory of Open Access Journals (Sweden)

    Mharakurwa Sungano

    2011-08-01

    Full Text Available Abstract Malaria in the 21st century is showing signs of declining over much of its distribution, including several countries in Africa where previously this was not thought to be feasible. Yet for the most part the strategies to attack the infection are similar to those of the 1950s. Three major Journals have recently drawn attention to the situation, stressing the importance of research, describing the successes and defining semantics related to control. But there is a need to stress the importance of local sustainability, and consider somewhat urgently how individual endemic countries can plan and implement the programmes that are currently financed, for the most part, by donor institutions. On an immediate basis research should be more focused on a data driven approach to control. This will entail new thinking on the role of local infrastructure and in training of local scientists in local universities in epidemiology and field malariology so that expanded control programmes can become operational. Donor agencies should encourage and facilitate development of career opportunities for such personnel so that local expertise is available to contribute appropriately.

  17. Control of group of mobile autonomous agents via local strategies

    Institute of Scientific and Technical Information of China (English)

    Lixin GAO; Daizhan CHENG; Yiguang HONG

    2008-01-01

    This paper considers the formation control problem of multi-agent systems in a distributed fashion.Two cases of the information propagating topologies among multiple agents,characterized by graphics model,are considered.One is fixed topology.The other is switching topology which represents the limited and less reliable information exchange.The local formation control strategies established in this paper are based on a simple modification of the existing consensus control strategies.Moreover,some existing convergence conditions ale shown to be a special case of our model even in the continuous-time consensus case.Therefore.the results of this paper extend the existing results about the consensus problem.

  18. Mine-Hoist Active Fault Tolerant Control System and Strategy

    Institute of Scientific and Technical Information of China (English)

    WANG Zhi-jie; WANG Yao-cai; MENG Jiang; ZHAO Peng-cheng; CHANG Yan-wei

    2005-01-01

    Based on fault diagnosis and fault tolerant technologies, the mine-hoist active fault-tolerant control system (MAFCS) is presented with corresponding strategies,, which includes the fault diagnosis module (FDM), the dynamic library (DL) and the fault-tolerant control module (FCM). When a fault is judged from some sensor by FDM, FCM reconfigure the state of MAFCS by calling the parameters from all sub libraries in DL, in order to ensure the reliability and safety of mine hoist. The simulating result shows that, MAFCS is of certain intelligence, which can adopt the corresponding control strategies according to different fault modes, even when there are quite difference between the real data and the prior fault modes.

  19. Optimal design of coordination control strategy for distributed generation system

    Institute of Scientific and Technical Information of China (English)

    WANG Ai-hua; Norapon Kanjanapadit

    2009-01-01

    This paper presents a novel design procedure for optimizing the power distribution strategy in distributed generation system. A coordinating controller, responsible to distribute the total load power request among multiple DG units, is suggested based on the conception of hierarchical control structure in the dynamic system.The optimal control problem was formulated as a nonlinear optimization problem subject to set of constraints.The resulting problem was solved using the Kutm-Tucker method. Computer simulation results demonstrate that the proposed method can provide better efficiency in terms of reducing total costs compared to existing methods.In addition, the proposed optimal load distribution strategy can be easily implemented in real-time thanks to the simplicity of closed-form solutions.

  20. Arduino based laser control

    OpenAIRE

    Bernal Muñoz, Ferran

    2015-01-01

    ARDUINO is a vey usefull platform for prototypes. In this project ARDUINO will be used for controling a Semiconductor Tuneable Laser. [ANGLÈS] Diode laser for communications control based on an Arduino board. Temperature control implementation. Software and hardware protection for the laser implementation. [CASTELLÀ] Control de un láser de comunicaciones ópticas desde el ordenador utilizando una placa Arduino. Implementación de un control de temperatura y protección software y hardware ...

  1. Study on the Fuzzy COntrol Strategy of Automobile with CVT

    Institute of Scientific and Technical Information of China (English)

    HuJianjun; QINDatong; 等

    2002-01-01

    In order to study the dynamic characteristics of automobile with a CVT system, a bond graph analysis model of continuously variable transmission is established.On the base of the simulation state space equations that are established with bond graph theory,a fuzzy control strategy with an expert system of starting process has been introduced.Considering uncertain system parameters and exterior resistance disturbing,the effect of the profile of membership function and the defuzzification algorthm on the capacity of the fuzzy controller has been studied.The result of simulation proves that the proposed fuzzy controller is effective and feasible,Such controller has been employed in the actual control and has proved practicable.The study lays a foundation for design of the fuzzy controller for automobile with a CVT system.

  2. Instantaneous Current Feedback Control Strategy on Buck Mode Inverter

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Control strategies for Buck mode inverter have important effect on static and dynamic characteristics, reliability, load capacity, and short-circuit resistance. Instantaneous current feedback control strategies include instantaneous inductor current feedback control and instantaneous capacitor current feedback control, both of which have essential difference. When the Buck mode inverter respectively adopts instantaneous inductor current and capacitor current feedback control strategies, characteristics of stability, output voltage and power, short circuit, nonlinear load and dynamic are fully investigated in this paper.

  3. [Harm reduction strategy in tobacco control].

    Science.gov (United States)

    Gorini, Giuseppe

    2011-01-01

    .Thus, California Department of Health Services prohibits promotion of snus and medicinal nicotine as a harm reduction strategy. However, the US Federal Family Smoking Prevention and Tobacco Control Act, signed by President Obama in 2009, places tobacco products under FDA jurisdiction: FDA must define criteria for lowering carcinogens and toxicants in tobacco products, making more available medicinal nicotine, evaluating PREPs, creating a federal Tobacco Control Agency.Which approaches is Italy going to follow?

  4. Evidence-Based Classroom Behaviour Management Strategies

    Science.gov (United States)

    Parsonson, Barry S.

    2012-01-01

    This paper reviews a range of evidence-based strategies for application by teachers to reduce disruptive and challenging behaviours in their classrooms. These include a number of antecedent strategies intended to help minimise the emergence of problematic behaviours and a range of those which provide positive consequences for appropriate student…

  5. 基于自适应全局滑模控制的微电网稳定控制策略%Stability Control Strategy for Microgrid Based on Adaptive Total Sliding-mode Control

    Institute of Scientific and Technical Information of China (English)

    苏小玲; 韩民晓; 孙海

    2014-01-01

    This paper developed a microgrid stability control strategy based on adaptive total sliding-mode control (SMC). A physical microgrid controller had been realized following the developed control strategy with energy storage unit. Analysis of microgrid operating characteristics and mathematical models of the controller according to the operation mode are given at first. As the system is inherently nonlinear, time-variable, the authors employ an adaptive total sliding-mode control (ATSMC) to ensure the stability and dynamics of the microgrid stability controller. The simulation and experimental results illustrate that the ARTSMC system is insensitivity to parametric uncertainty and external disturbances. The fast dynamic response and robust control performance of microgrid stability controller ensure the stable operation of microgrid in both modes. It improves controllability of the exchange power between microgrid and utility network, smooth DG output power while the microgrid working in grid-connected mode, provides voltage and frequency support when the microgrid working in islanding mode, meanwhile it ensure seamless transaction between the two operation modes.%设计了一种基于自适应全局滑模控制的微电网稳定控制策略,并基于储能设备开发了相应的微电网稳定控制器。根据微电网的不同运行方式,首先分析稳定控制器的运行特性,建立稳定控制器的数学模型。考虑到系统的不确定性和非线性,该文为微电网稳定控制器提出自适应鲁棒全局滑模控制系统,保证系统在参数不确定、存在外界干扰等情况下的稳态及动态特性。仿真和实验结果证明,微电网稳定控制器能够保证微电网在不同运行模式下的稳定性。在微电网并网运行时有效地抑制微电网与主电网交换功率波动,达到微电网与主电网交换功率可控;在微电网孤岛运行时,提供电压、频率支持;实现微电网在2种运行模式之间无缝切换。

  6. MARKETING STRATEGIES BASED ON THE BUYING PROCESS

    Directory of Open Access Journals (Sweden)

    LIVIU NEAMŢU

    2016-04-01

    Full Text Available In marketing, due to dynamic, rapid and permanent changes known on the market, we will talk more about politics than about strategy, the time horizon covered is much lower than that contained in a classic strategy, with a risk that elements and criteria to which we refer are no longer current. Sales growth strategies are, in fact, combination strategies and consist in the company applying, in its different units, different strategies, according to the requirement of appropriate strategies applied to different environments of action. A business strategy must be based on knowledge of customer purchasing behavior. To contact customers, a company may use one or more specific strategies. Every marketing strategy serves the interest of increasing competitiveness, and of stabilizing and improving the companys position in the market in a highly competitive environment. In the age of transformation into market economy, rapid technological development, and confrontation between economic and ecological factors, every single manager is compelled to elaborate an attitude, and to take a stand concerning research and development, technological transfer, the technological level of products, and the quality of services, because these are the factors determining the future development, the chances of survival, and in a wider sense the objectives of marketing strategy.

  7. Cost Effectiveness Analysis of Optimal Malaria Control Strategies in Kenya

    Directory of Open Access Journals (Sweden)

    Gabriel Otieno

    2016-03-01

    Full Text Available Malaria remains a leading cause of mortality and morbidity among the children under five and pregnant women in sub-Saharan Africa, but it is preventable and controllable provided current recommended interventions are properly implemented. Better utilization of malaria intervention strategies will ensure the gain for the value for money and producing health improvements in the most cost effective way. The purpose of the value for money drive is to develop a better understanding (and better articulation of costs and results so that more informed, evidence-based choices could be made. Cost effectiveness analysis is carried out to inform decision makers on how to determine where to allocate resources for malaria interventions. This study carries out cost effective analysis of one or all possible combinations of the optimal malaria control strategies (Insecticide Treated Bednets—ITNs, Treatment, Indoor Residual Spray—IRS and Intermittent Preventive Treatment for Pregnant Women—IPTp for the four different transmission settings in order to assess the extent to which the intervention strategies are beneficial and cost effective. For the four different transmission settings in Kenya the optimal solution for the 15 strategies and their associated effectiveness are computed. Cost-effective analysis using Incremental Cost Effectiveness Ratio (ICER was done after ranking the strategies in order of the increasing effectiveness (total infections averted. The findings shows that for the endemic regions the combination of ITNs, IRS, and IPTp was the most cost-effective of all the combined strategies developed in this study for malaria disease control and prevention; for the epidemic prone areas is the combination of the treatment and IRS; for seasonal areas is the use of ITNs plus treatment; and for the low risk areas is the use of treatment only. Malaria transmission in Kenya can be minimized through tailor-made intervention strategies for malaria control

  8. Application of a Pull Strategy Based on Fuzzy Control for Production Control of Assembly Line%基于模糊控制的拉式策略在装配生产控制中的应用

    Institute of Scientific and Technical Information of China (English)

    莫巨华; 黄敏; 王兴伟

    2011-01-01

    利用模糊控制鲁棒性强的特点,将其引入单产品装配线的生产控制系统中,构造新的拉式控制策略.在建立控制系统周期审查模型和完成控制器设计的基础上,通过缩小变异范围改进遗传算法求解以极小化在制品量和投放波动为目标,顾客满意率为约束条件的多目标规划,从而达到优化控制系统参数的目的.为考察模糊控制系统性能,通过实例与多阶段定量在制品法(Constant work-in-process,CoNWIP)、Kauban和一般拉式策略(Generic pull,GP)系统进行比较,结果表明模糊生产控制系统不仅能维持较低的在制品水平,更重要的是能维持较低的订单投放波动水平.%Due to its robustness, fuzzy control has been incorporated into the production control system to establish a pull strategy for single-product assembly line. Based on a periodic review model proposed to describe the operations of the assembly control system and on the designs of the fuzzy controllers,the basic genetic algorithm (GA) has been improved via reducing mutation domains to solve a multi-objective program, which minimizes the work-in-procees level and fluctuation level of order placement while meeting customer's demand, meanwhile,the parameters of the control system have been optimized. In order to investigate the performance of the proposed fuzzy control system, multi-CONWIP, Kanban and generic pull systems have been compared with the fuzzy system, and the results show that the fuzzy production control system keeps a lower work-inprocess level, and especially a weaker placement fluctuation.

  9. 无刷双馈电机滑模变结构直接转矩控制%Direct-torque control of the brushless double-fed machines based on sliding-mode variable structure control strategy

    Institute of Scientific and Technical Information of China (English)

    杨俊华; 刘远涛; 谢景凤; 刘慧媛; 吴捷

    2011-01-01

    A novel sliding-mode variable structure(SMVS) control strategy is proposed to reduce the ripples of ?ux and torque of brushless double-fed machines(BDFM) based on direct torque control system(DTC).In order to ensure the constant switching frequency for the inverter,two hysteresis regulators in the conventional DTC system are substituted by the SMVS controllers of ?ux and torque,and the space voltage vector pulse-width-modulation is used in the output of the voltage vector switches.The SMVS controllers are designed with the method of exponential approach law,and the Lyapunov stability theory is utilized to solve for the control law of the SMVS controllers.The simulation model of DTC is established in MATLAB/Simulink environment.The simulation results show that this new control method effectively reduces the torque ripples and improves the waveforms of the stator ?ux and current.The inherent advantage of the fast dynamic-response of the torque in DTC is reserved.The stability and robust performance of the system is enhanced.%针对无刷双馈电机直接转矩控制系统磁链和转矩脉动大的问题,引入滑模变结构控制策略.以转矩和磁链两个滑模控制器来代替传统直接转矩控制中的两个滞环控制器,电压矢量开关的输出采用空间电压矢量PWM调制的方法,保证了逆变器开关频率恒定,应用指数趋近率方法设计滑模控制器,由Lyapunov方法求得相应的滑模变结构控制律,建立了MATLAB/Simulink环境下直接转矩控制系统的仿真模型,仿真结果表明,新型控制方案能有效减小转矩脉动,改善定子磁链和电流波形,同时仍可保持直接转矩控制固有的转矩快速响应的优点,提高系统的稳定性和鲁棒性.

  10. Strategies for searching and managing evidence-based practice resources.

    Science.gov (United States)

    Robb, Meigan; Shellenbarger, Teresa

    2014-10-01

    Evidence-based nursing practice requires the use of effective search strategies to locate relevant resources to guide practice change. Continuing education and staff development professionals can assist nurses to conduct effective literature searches. This article provides suggestions for strategies to aid in identifying search terms. Strategies also are recommended for refining searches by using controlled vocabulary, truncation, Boolean operators, PICOT (Population/Patient Problem, Intervention, Comparison, Outcome, Time) searching, and search limits. Suggestions for methods of managing resources also are identified. Using these approaches will assist in more effective literature searches and may help evidence-based practice decisions.

  11. 基于遗传算法的双馈风场分群无功控制策略%A clustering reactive power control strategy in DFIG-based wind farm based on genetic algorithm

    Institute of Scientific and Technical Information of China (English)

    徐蒙福; 于乐征; 朱加明; 杨博; 方臣

    2016-01-01

    现有的双馈风电场无功控制多数采用恒功率因数控制,既没有充分利用风电场内双馈风电机组和无功补偿设备的无功调节能力,也没有考虑风电场集电系统的网损。提出了一种综合考虑集电系统特点和DFIG无功调节能力的无功控制策略,该策略以实时监测的风电场并网点电压数据和DFIG有功出力数据为基础,通过分析双馈风电机组的功率特性和风电场的无功需求,利用遗传算法求解风电场多目标无功优化控制模型,达到降低集电系统网损和改善并网点电压的目的。对某实际风场的仿真算例验证了所提策略的有效性。%Most of the reactive power control of doubly-fed wind farm uses the constant power factor control , which doesn’ t make full use of the reactive power adjustment capability of DFIG and reactive compensation equipment in doubly-fed wind farm , nor does it takes the network-loss in the power collector system into consideration .This paper presents a comprehensive consideration of the characteristics of current collector systems and reactive power regulation capabilities of DFIG for reactive power control strategy .The strategy is based on the real-time monitoring date includes the point of common coupling and active power output date of DFIG , according to analysis the power characteristics of DFIG and the reactive power demand of wind farm , it uses the genetic algorithm for multi-objective reactive power op-timization control model of wind farm to reduce network-loss of the collector system and improve the power quality of the point of common coupling .A simulation case of an actual wind field verifies the validity of the strategy .

  12. Improved Control Strategy for Active Bouncers used in Klystron Modulators

    CERN Document Server

    Aguglia, D; Benedetti, M; Garcia Retegui, R; Maestri, S; Nisbet, D

    2012-01-01

    This paper introduces a closed-loop control system for klystron modulators. The system is based on the discharge of a capacitor into a step-up voltage transformer and an active bouncer implemented with a multiphase buck converter. In order to obtain a constant Klystron voltage at the at-top, the active bouncer must compensate both the capacitor discharge and the pulse transformer characteristic. The proposed control includes an inner voltage regulation loop that controls the active bouncer output voltage and an outer one that controls the klystron voltage. The primary side current and main capacitor voltage are included in the regulation loops to simplify the controllers. Simulations demonstrate that the strategy adopted allows to obtain a precision better than 0:1% on a 110 kV klystron. Experimental tests have shown that the multiphase converter is able to track a high dynamics reference even under variable output voltage conditions.

  13. Modeling Responses of Leafy Spurge Dispersal to Control Strategies

    Institute of Scientific and Technical Information of China (English)

    Zewei Miao

    2007-01-01

    Leafy spurge (Euphorbia esula L.) has substantial negative effects on grassland biodiversity, productivity, and economic benefit in North America.To predict these negative impacts, we need an appropriate plant-spread model which can simulate the response of an invading population to different control strategies.In this study, using a stochastic map lattice approach we generated a spatially explicitly stochastic process-based model to simulate dispersal trajectories of leafy spurge under various control scenarios.The model integrated dispersal curve, propagule pressure, and population growth of leafy spurge at local and short-temporal scales to capture spread features of leafy spurge at large spatial and long-temporal scales.Our results suggested that narrow-, medium-, and fat-tailed kernels did not differ In their ability to predict spread, in contrast to previous works.For all kernels, Allee effects were significantly present and could explain the lag phase (three decades)before leafy spurge spread accelerated.When simulating from the initial stage of introduction, Allee effects were critical in predicting spread rate of leafy spurge, because the prediction could be seriously affected by the low density period of leafy spurge community.No Allee effects models were not able to simulate spread rate well in this circumstance.When applying control strategies to the current diatribution, Allee effects could stop the spread of leafy spurge; no Allee effects models, however, were able to slow but not stop the spread.The presence of Allee effects had significant ramifications on the efficiencies of control strategies.For both Allee and no Allee effects models, the later that control strategies were implemented, the more effort had to be input to achieve similar control results.

  14. Benchmarking of Control Strategies for Wastewater Treatment Plants

    DEFF Research Database (Denmark)

    Wastewater treatment plants are large non-linear systems subject to large perturbations in wastewater flow rate, load and composition. Nevertheless these plants have to be operated continuously, meeting stricter and stricter regulations. Many control strategies have been proposed in the literature...... for improved and more efficient operation of wastewater treatment plants. Unfortunately, their evaluation and comparison – either practical or based on simulation – is difficult. This is partly due to the variability of the influent, to the complexity of the biological and biochemical phenomena......, plant layout, controllers, sensors, performance criteria and test procedures, i.e. a complete benchmarking protocol....

  15. An optimal reactive power control strategy for a DFIG-based wind farm to damp the sub-synchronous oscillation of a power system

    DEFF Research Database (Denmark)

    Zhao, Bin; Li, Hui; Wang, Mingyu

    2014-01-01

    This study presents the auxiliary damping control with the reactive power loop on the rotor-side converter of doubly-fed induction generator (DFIG)-based wind farms to depress the sub-synchronous resonance oscillations in nearby turbogenerators. These generators are connected to a series capaciti...

  16. An improved PID switching control strategy for type 1 diabetes.

    Science.gov (United States)

    Marchetti, Gianni; Barolo, Massimiliano; Jovanovic, Lois; Zisser, Howard; Seborg, Dale E

    2008-03-01

    In order for an "artificial pancreas" to become a reality for ambulatory use, a practical closed-loop control strategy must be developed and validated. In this paper, an improved PID control strategy for blood glucose control is proposed and critically evaluated in silico using a physiologic model of Hovorka et al. [1]. The key features of the proposed control strategy are: 1) a switching strategy for initiating PID control after a meal and insulin bolus; 2) a novel time-varying setpoint trajectory; 3) noise and derivative filters to reduce sensitivity to sensor noise; and 4) a practical controller tuning strategy. Simulation results demonstrate that proposed control strategy compares favorably to alternatives for realistic conditions that include meal challenges, incorrect carbohydrate meal estimates, changes in insulin sensitivity, and measurement noise.

  17. Application of Feedforward and Feedback Control Strategy for Wire Rod Hot Rolling Line

    Institute of Scientific and Technical Information of China (English)

    ZHU Hong-xiang; HAO Xiao-hong; WEN Zhi; HU Ze-qiang; ZHANG Yao-gen; CHEN Hu-qiu

    2005-01-01

    The feedforward and feedback control strategy of water flowrate based on the analysis of thermal process in water cooling box was proposed, and the control strategy was applied to wire rod hot rolling at Baosteel Co.The operation has proved that the strategy can control water flowrate in the cooling water box reasonably to ensure the temperature requirement of the wire discharged from the cooling water box.

  18. Control strategies for effective robot assisted gait rehabilitation: the state of art and future prospects.

    Science.gov (United States)

    Cao, Jinghui; Xie, Sheng Quan; Das, Raj; Zhu, Guo L

    2014-12-01

    A large number of gait rehabilitation robots, together with a variety of control strategies, have been developed and evaluated during the last decade. Initially, control strategies applied to rehabilitation robots were adapted from those applied to traditional industrial robots. However, these strategies cannot optimise effectiveness of gait rehabilitation. As a result, researchers have been investigating control strategies tailored for the needs of rehabilitation. Among these control strategies, assisted-as-needed (AAN) control is one of the most popular research topics in this field. AAN training strategies have gained the theoretical and practical evidence based backup from motor learning principles and clinical studies. Various approaches to AAN training have been proposed and investigated by research groups all around the world. This article presents a review on control algorithms of gait rehabilitation robots to summarise related knowledge and investigate potential trends of development. There are existing review papers on control strategies of rehabilitation robots. The review by Marchal-Crespo and Reinkensmeyer (2009) had a broad cover of control strategies of all kinds of rehabilitation robots. Hussain et al. (2011) had specifically focused on treadmill gait training robots and covered a limited number of control implementations on them. This review article encompasses more detailed information on control strategies for robot assisted gait rehabilitation, but is not limited to treadmill based training. It also investigates the potential to further develop assist-as-needed gait training based on assessments of patients' ability. In this paper, control strategies are generally divided into the trajectory tracking control and AAN control. The review covers these two basic categories, as well as other control algorithm and technologies derived from them, such as biofeedback control. Assessments on human gait ability are also included to investigate how to

  19. Solar shading control strategy for office buildings in cold climate

    DEFF Research Database (Denmark)

    Karlsen, Line Røseth; Heiselberg, Per Kvols; Bryn, Ida;

    2016-01-01

    Highlights •Solar shading control strategy for office buildings in cold climate is developed. •Satisfying energy and indoor environmental performance is confirmed. •Importance of integrated evaluations when selecting shading strategy is illustrated.......Highlights •Solar shading control strategy for office buildings in cold climate is developed. •Satisfying energy and indoor environmental performance is confirmed. •Importance of integrated evaluations when selecting shading strategy is illustrated....

  20. FAB (Functionally Alert Behavior Strategies) to Improve Self-Control

    Science.gov (United States)

    Pagano, John

    2015-01-01

    This paper describes the FAB (Functionally Alert Behavior) Strategies approach to improve behavior in children and adolescents with complex behavioral challenges. FAB Strategies include evidence-based environmental adaptations, sensory modulation, positive behavioral support, and physical self-regulation strategies. FAB Strategies can be used by…

  1. Economic Analysis of HPAI Control in the Netherlands II: Comparison of Control Strategies

    NARCIS (Netherlands)

    Longworth, N.J.; Mourits, Monique C.M.; Saatkamp, H.W.

    2014-01-01

    A combined epidemiological-economic modelling approach was used to analyse strategies for highly pathogenic avian influenza (HPAI) control for the Netherlands. The modelling framework used was InterSpread Plus (ISP), a spatially based, stochastic and dynamic simulation model. A total of eight contro

  2. Study on Product Quality Cooperative Control Based on Different Negotiating Strategies%基于不同谈判策略的产品质量协同控制研究

    Institute of Scientific and Technical Information of China (English)

    陈瑞义; 盛昭瀚; 徐峰

    2014-01-01

    基于谈判实力和谈判策略视角,研究品牌零售商与生产商之间产品质量协同策略选择问题,分别对弱合作型谈判策略、中合作型谈判策略和强合作型谈判策略进行探讨,并给出3种策略下产品的最优质量、最优批发价和各成员最优利润。在此基础上,对集中控制策略和生产商 Stackelberg 控制策略进行分析,并对5种策略进行比较分析和数值算例说明。研究结果表明,零售商谈判实力增大对生产商利润的挤压若得不到适当利润补救将导致产品质量合作双重边际效应;强合作型谈判策略不仅可以消除产品质量合作双重边际效应,还可实现等价于集中控制策略下的最佳产品质量与供应链利润协同;强合作型谈判策略并非总是零售商占优策略选择,基于适度合作诚意的谈判策略选择是实现零售商与生产商之间产品质量协同的关键。%Based on the perspective of negotiating power and negotiating strategy , this study explores the choice of products quali-ty cooperative strategies between the brand retailer and manufacturer , investigates week cooperative negotiating strategy , proper cooperative negotiating strategy and strong cooperative negotiating strategy , and proposes the optimal quality , optimal wholesale prices, optimal profits of participants in supply chains in the above three strategies .Then we analyze the centralized control strat-egy and the manufacture Stackelberg control strategy , compare the above five strategies , and give numerical examples of the five strategies.Results show that:①double marginalization of product quality cooperation will arise if there is no appropriate remedy to compensate the manufacture profit squeezed by the increase of retailer negotiation power ;②strong cooperative negotiating strat-egy not only eliminates the double marginalization of product quality cooperation , but also realizes the coordination of

  3. Dynamic Flow Control Strategies of Vehicle SCR Urea Dosing System

    Institute of Scientific and Technical Information of China (English)

    LIN Wei; ZHANG Youtong; ASIF Malik

    2015-01-01

    Selective Catalyst Reduction(SCR) Urea Dosing System(UDS) directly affects the system accuracy and the dynamic response performance of a vehicle. However, the UDS dynamic response is hard to keep up with the changes of the engine’s operating conditions. That will lead to low NOX conversion efficiency or NH3 slip. In order to optimize the injection accuracy and the response speed of the UDS in dynamic conditions, an advanced control strategy based on an air-assisted volumetric UDS is presented. It covers the methods of flow compensation and switching working conditions. The strategy is authenticated on an UDS and tested in different dynamic conditions. The result shows that the control strategy discussed results in higher dynamic accuracy and faster dynamic response speed of UDS. The inject deviation range is improved from being between–8%and 10%to–4%and 2%and became more stable than before, and the dynamic response time was shortened from 200 ms to 150 ms . The ETC cycle result shows that after using the new strategy the NH3 emission is reduced by 60%, and the NOX emission remains almost unchanged. The trade-off between NOX conversion efficiency and NH3 slip is mitigated. The studied flow compensation and switching working conditions can improve the dynamic performance of the UDS significantly and make the UDS dynamic response keep up with the changes of the engine’s operating conditions quickly.

  4. Optimal Control Strategies in a Two Dimensional Differential Game Using Linear Equation under a Perturbed System

    Directory of Open Access Journals (Sweden)

    Musa Danjuma SHEHU

    2008-06-01

    Full Text Available This paper lays emphasis on formulation of two dimensional differential games via optimal control theory and consideration of control systems whose dynamics is described by a system of Ordinary Differential equation in the form of linear equation under the influence of two controls U(. and V(.. Base on this, strategies were constructed. Hence we determine the optimal strategy for a control say U(. under a perturbation generated by the second control V(. within a given manifold M.

  5. An off-and-towards-equilibrium strategy for vibrational control of structures

    Institute of Scientific and Technical Information of China (English)

    Yang Runlin; Mai Tong; Zhou Xiyuan; Yan Weiming; Liu Xihui

    2006-01-01

    Traditional control strategies have difficulty handling nonlinear behavior of structures, time variable features and parameter uncertainties of structural control systems under seismic excitation. An off-and-towardsequilibrium (OTE) strategy combined with fuzzy control is presented in this paper to overcome these difficulties.According to the OTE strategy, the control force is designed from the viewpoint of a mechanical relationship between the motions of the structure, the exciting force and the control force. The advantage of the OTE strategy is that it can be used for a variety of control systems. In order to evaluate the performance of the proposed strategy, the seismic performance of a three-story shear building with an Active Tendon System (ATS) using a Fuzzy Logic Controller (FLC) is studied. The main advantage of the fuzzy controller is its inherent robustness and ability to handle any nonlinear behavior of structures. However, there are no design guidelines to set up the corresponding control rule table for a FLC. Based on the proposed strategy for the FLC, a control rule table associated with the building under study is developed, which then allows formation of a detailed algorithm. The results obtained in this study show that the proposed strategy performs slightly better than the linear quadratic regulator (LQR) strategy, while possessing several advantages over the LQR controller. Consequently, the feasibility and validity of the proposed strategy are verified.

  6. Improving epidemic control strategies by extended detection

    Science.gov (United States)

    Karp, Paweł; Dybiec, Bartłomiej; Kleczkowski, Adam

    2014-11-01

    Majority of epidemics eradication programs work in preventive responsive way. The lack of exact information about epidemiological status of individuals makes responsive actions less efficient. Here, we demonstrate that additional tests can significantly increase the efficiency of "blind" treatment (vaccination or culling). Eradication strategy consisting of "blind" treatment in very limited local neighborhood supplemented by extra tests in a little bit larger neighborhood is able to prevent invasion of even highly infectious diseases and to achieve this at a cost lower than for the "blind" strategy. The effectiveness of the extended strategy depends on such parameters as the test efficiency and test cost.

  7. Maternal Control Strategies, Maternal Language Usage and Children's Language Usage at Two Years

    Science.gov (United States)

    Taylor, Nicole; Donovan, Wilberta; Miles, Sally; Leavitt, Lewis

    2009-01-01

    The present study determined whether parenting style, defined by control strategies varying in power-assertion mediated the established relation between maternal language usage (grammar and semantics) and child language (grammar, semantics and pragmatics) during toddlerhood (n = 60). Based upon their use of control strategies mothers were…

  8. 神华集团基于产业链控制的财务战略选择%Selection of financial strategy based on industry chain control of Shenhua Group

    Institute of Scientific and Technical Information of China (English)

    谷增军

    2013-01-01

    在调查研究获取第一手资料的基础上,对神华集团的产业链进行了分析,总结了神华集团实施能源一体化业务发展总体战略面临的财务困境,并对神华集团基于产业链控制的财务战略选择进行了探讨。%Based on the obtained firstGhand data through investigation and research,the paG per analyzes the industry chain of Shenhua Group�It summarizes the financial distress faced by Shenhua Group in implementing the overall strategy of energy integration business development, and discusses the selection of financial strategy based on industry chain control of Shenhua Group.

  9. Application of a controllable degron strategy for metabolic engineering

    DEFF Research Database (Denmark)

    Knuf, Christoph; Maury, Jerome; Jacobsen, Simo Abdessamad;

    2014-01-01

    , as the existing enzyme will still be active. We present a strategy for down-regulation that acts on the protein level and which can therefore be controlled in a more precise manner than the hitherto reported strategies. As a case study we show the action of the degron strategy for controlling the pools...... terpenoids, can be produced from intermediates of this pathway. Different strategies have been applied in order to down-regulate the expression of enzymes involved in the mevalonate pathway. All these strategies work on the transcriptional level. This leads to a delay of the actual regulation...

  10. Pain coping strategies predict perceived control over pain.

    Science.gov (United States)

    Haythornthwaite, J A; Menefee, L A; Heinberg, L J; Clark, M R

    1998-07-01

    Perceptions of control over pain and specific pain coping strategies are associated with a number of positive outcomes in patients with chronic pain conditions. Transactional models of stress have emphasized coping as a process that is both determined by, and influences appraisals of control. While perceptions of control and coping efforts are associated with better adjustment, little is known about the specific coping strategies that contribute to perceptions that pain is controllable. One hundred and ninety-five (65% female) individuals with chronic pain conditions admitted to an inpatient unit completed the Multidimensional Pain Inventory, the Survey of Pain Attitudes and the Coping Strategies Questionnaire. Stepwise multiple regression analyses were used to predict perceived pain control from measures of pain severity and coping. After controlling for pain severity and education, coping self-statements and reinterpreting pain sensations predicted greater perceptions of control over pain, whereas ignoring pain sensations predicted lower perceptions of control over pain. The coping strategies did not interact with pain severity in predicting perceptions of control. Coping flexibility, or the number of pain coping strategies reported at a high frequency, also predicted perceptions of control over pain and did not interact with pain severity. The present findings suggest that, regardless of pain severity, the use of specific cognitive pain coping strategies may increase perceptions of control over pain. Since the existing coping literature largely identifies maladaptive pain coping strategies, it is especially critical to establish which pain coping strategies are adaptive. Specific cognitive strategies, particularly coping self statements, are important components for cognitive-behavioral interventions for chronic pain management. Future research will need to determine whether other adaptive cognitive strategies such as reinterpreting pain sensations can be

  11. Research on control strategy of regenerative braking system based on HEV%HEV再生制动控制策略的研究

    Institute of Scientific and Technical Information of China (English)

    仇秋飞; 朱伟; 赵云飞; 吴叶青

    2011-01-01

    Regenerative braking is not only a significant characteristic of EV, but also can improve its economic efficiency. The constraints are analyzed in the course of braking energy recovery. Then by designing the vehicle structure and the control strategy of regenerative braking system to resolve or weaken the problem that limits the braking energy recovery, meeting the design' s objective. At last, the test is done on the road, and the result indicates: 25% power can be recovered, and the mileage is prolonged.%制动能量回收是电动汽车的一个重要特性,也是电动汽车能实现经济性的重要方面.分析了制动能量回收过程中的限制因素,然后通过对整车系统结构以及再生制动控制策略的设计,削弱并解决了这些因素对制动能量回收的限制,以达到设计目的.最后进行道路试验,试验结果表明:在多模式驱动下该新型混合动力的再生制动系统可以回收总能量的25%,延长了续驶里程.

  12. A Sliding Mode Control Using Brain Limbic System Control Strategy for a Robotic Manipulator

    Directory of Open Access Journals (Sweden)

    Hak Yi

    2015-11-01

    Full Text Available This paper presents a robust bio-inspired sliding mode control approach, designed to achieve a favourable tracking performance in a class of robotic manipulators with uncertainties. To this end, brain emotional learning-based intelligent control (BELBIC is applied, to adaptively adjust the control input law in the sliding mode control. The combined form provides an adjustment of the control input law that effectively alleviates the chattering effects of the sliding mode control. Specifically, the online parameters computed from the parameter uncertainties and external disturbances help to improve the system robustness. The simulation results demonstrate that the proposed bio-inspired control strategy is very successful at tracking the given trajectories with less chattering, as compared to both the conventional and fuzzy sling mode control schemes.

  13. Control strategy of microbial fuel cell based on generalized predictive control%基于广义预测控制策略的微生物燃料电池控制

    Institute of Scientific and Technical Information of China (English)

    安爱民; 王静; 张浩琛; 杨国强; 刘云利

    2016-01-01

    The generalized predictive control is proposed that based on the control strategy of microbial fuel cell, combined with the characteristics of microbial fuel cells, to investigate the problems of unstable power output in the initial operation stage and the long adjustment time during the operation of an MFC, compared with the MFC system of PID control method joined, joined generalized predictive control of MFC system output is able to avoid the response greatly jitter and fast response, good robustness and dynamic adjustment to ensure that the dynamic output curve fast and accurate tracking system settings. The model identification is carried by the least squares method with forgetting factor to get linear model as a predictive model. Then, generalized predictive control (GPC) can adjust effectively the output response of an MFC under random influent flow at constant external resistance and acetate concentration. The simulation results show that GPC can achieve a good control effect and system robustness adjustment process has also been greatly improved in terms of speed control response. Effective implementation of the optimization of dynamic performance and robust performance of microbial fuel cell system to verify the proposed algorithm is effective and feasible.%针对 MFC 系统启动阶段输出响应不稳定以及调节时间较长的问题,结合微生物燃料电池自身特性,提出了基于广义预测控制(generalized predictive control,GPC)的微生物燃料电池(microbial fuel cell,MFC)控制策略。与加入PID控制方法对比得知,加入GPC的MFC系统输出能够避免响应出现大幅度的抖动,且响应速度快,动态调节鲁棒性好,保证了动态输出曲线快速准确地跟踪系统设定值。在给定外电阻为恒值和醋酸盐浓度随时间阶梯变化时,通过带遗忘因子的最小二乘法进行模型辨识,将所得线性模型作为预测模型,采用GPC算法进行控制。仿真表

  14. 模块化多电平变流器HVDC输电系统控制策略%Control Strategy of Modular Multilevel Converters Based HVDC Transmission

    Institute of Scientific and Technical Information of China (English)

    赵岩; 胡学浩; 汤广福; 贺之渊

    2011-01-01

    This paper built an electromagnetic transient mathematical model of modular multilevel converters (MMCs) and dynamic model of DC voltage in high voltage direct current (HVDC) transmission that adopts MMC as converter. Based on it, the dynamic characteristic of DC voltage in HVDC transmission was analyzed, and HVDC control system parameters coordinated design principles and its algorithm were proposed. Finally, the correctness of proposed submodule capacitor voltage balancing scheme, MMC based HVDC control system parameters coordinated design principles and its algorithm were verified by digital simulation based on PSCAD/EMTDC.%建立模块化多电平变流器(modular multilevel converters,MMCl的电磁暂态数学模型以及采用MMC为变流器的高压直流输电系统(high voltage direct current,HVDC)直流侧电压的动态数学模型。在此基础上,分析HVDC系统的直流侧电压动态特性,给出HVDC控制器参数协调设计原则和算法。最后,基于PscAD/EMTDc的数字仿真结果证明了所提出的HVDC控制系统参数协调设计原则和算法的正确性。

  15. Benchmarking of Advanced Control Strategies for a Simulated Hydroelectric System

    Science.gov (United States)

    Finotti, S.; Simani, S.; Alvisi, S.; Venturini, M.

    2017-01-01

    This paper analyses and develops the design of advanced control strategies for a typical hydroelectric plant during unsteady conditions, performed in the Matlab and Simulink environments. The hydraulic system consists of a high water head and a long penstock with upstream and downstream surge tanks, and is equipped with a Francis turbine. The nonlinear characteristics of hydraulic turbine and the inelastic water hammer effects were considered to calculate and simulate the hydraulic transients. With reference to the control solutions addressed in this work, the proposed methodologies rely on data-driven and model-based approaches applied to the system under monitoring. Extensive simulations and comparisons serve to determine the best solution for the development of the most effective, robust and reliable control tool when applied to the considered hydraulic system.

  16. CAN-based Synchronized Motion Control for Induction Motors

    Institute of Scientific and Technical Information of China (English)

    Jun Ren; Chun-Wen Li; De-Zong Zhao

    2009-01-01

    A control area network (CAN) based multi-motor synchronized motion control system with an advanced synchronized control strategy is proposed.The strategy is to incorporate the adjacent cross-coupling control strategy into the sliding mode control architecture. As illustrated by the four-induction-motor-based experimental results,the multi-motor synchronized motion control system,via the CAN bus,has been successfully implemented.With the employment of the advanced synchronized motion control strategy,the synchronization performance can be significantly improved.

  17. Activity-Based Information Integrating the operations strategy

    Directory of Open Access Journals (Sweden)

    José Augusto da Rocha de Araujo

    2005-12-01

    Full Text Available In the globalized world, companies seek for new operations strategies to ensure world corporate success. This article analyzes how the cost management models – both traditional and activity-based, aid the planning and management of corporate globalized operations. The efficacy of the models application depends on their alignment with the competitive strategy. Companies must evaluate the nature of the competition and its competitive priorities; they should then define the necessary and sufficient dependence level on costs information. In this article, three dependence levels are presented: operational, decision support and strategic control. The result of the research shows the importance of alignment between the cost management model and the competitive strategy for corporate success, and confirms the adequacy of the activity-based costing model as a supporting tool for decision taking in a global strategy. Case studies in world class companies in Brazil are presented.

  18. Application of new control strategy for sun tracking

    Energy Technology Data Exchange (ETDEWEB)

    Rubio, F.R.; Ortega, M.G.; Gordillo, F.; Lopez-Martinez, M. [Depto. Ingenieria de Sistemas y Automatica, Escuela Superior de Ingenieros, Universidad de Sevilla, 41092 Sevilla (Spain)

    2007-07-15

    The application of high concentration solar cells technology allows a significant increase in the amount of energy collected by solar arrays per unit area. However, to make it possible, more severe specifications on the sun pointing error are required. In fact, the performance of solar cells with concentrators decreases drastically if this error is greater than a small value. These specifications are not fulfilled by simple tracking systems due to different sources of errors (e.g., small misalignments of the structure with respect to geographical north) that appear in practice in low cost, domestic applications. This paper presents a control application of a sun tracker that is able to follow the sun with high accuracy without the necessity of either a precise procedure of installation or recalibration. A hybrid tracking system that consists of a combination of open loop tracking strategies based on solar movement models and closed loop strategies using a dynamic feedback controller is presented. Energy saving factors are taken into account, which implies that, among other factors, the sun is not constantly tracked with the same accuracy, to prevent energy overconsumption by the motors. Simulation and experimental results with a low cost two axes solar tracker are exposed, including a comparison between a classical open loop tracking strategy and the proposed hybrid one. (author)

  19. A Comparative Study between Two Control Strategies for Matrix Converter

    OpenAIRE

    BENDIABDELLAH, A.; BACHIR, G.

    2009-01-01

    The authors compare two control strategies for direct AC-AC matrix converters; namely the Venturini method and the scalar strategy control method. The performance comparison of the two strategies is made under unbalanced distorted torque, rotor speed and stator current operation. The simulation of the three-phase matrix converter feeding an induction motor was accomplished by means of the Matlab/Simulink software. This package makes it possible to simulate the dynamic systems in a simple wa...

  20. 40 CFR 52.350 - Control strategy: Ozone.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy: Ozone. 52.350 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Colorado § 52.350 Control strategy: Ozone. (a) Revisions to the Colorado State Implementation Plan, 1-hour ozone NAAQS Redesignation Request and...

  1. 40 CFR 52.377 - Control strategy: Ozone.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy: Ozone. 52.377 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Connecticut § 52.377 Control strategy: Ozone. (a... requirements of sections 172(c)(9) and 182(c)(9) of the Clean Air Act, for the Greater Hartford serious...

  2. 40 CFR 52.930 - Control strategy: Ozone.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy: Ozone. 52.930 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Kentucky § 52.930 Control strategy: Ozone. (a) The VOC..., Campbell and Kenton Counties) ozone nonattainment area. The demonstration of attainment of the...

  3. 40 CFR 52.66 - Control Strategy: Ozone.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control Strategy: Ozone. 52.66 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Alabama § 52.66 Control Strategy: Ozone. (a) The redesignation request submitted by the State of Alabama, on March 16, 1995 for the Birmingham marginal...

  4. 40 CFR 52.476 - Control strategy: ozone.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy: ozone. 52.476 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS District of Columbia § 52.476 Control strategy: ozone. (a... of Progress Plan for the District of Columbia's portion of the Metropolitan Washington, D.C....

  5. 40 CFR 52.582 - Control strategy: Ozone.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy: Ozone. 52.582 Section 52.582 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Georgia> § 52.582 Control strategy: Ozone. (a)...

  6. 40 CFR 52.58 - Control strategy: Lead.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy: Lead. 52.58 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Alabama § 52.58 Control strategy: Lead. The lead plan... the lead standard throughout Alabama. The lead plan submitted by the State on October 7, 1985,...

  7. 40 CFR 52.1375 - Control strategy: Lead.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Lead. 52.1375 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Montana § 52.1375 Control strategy: Lead. Determination—EPA has determined that the East Helena Lead nonattainment area has attained the lead...

  8. 40 CFR 52.2236 - Control strategy; lead.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy; lead. 52.2236 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) Tennessee § 52.2236 Control strategy; lead... on October 6, 1994. These revisions address the requirements necessary to change a lead...

  9. 40 CFR 52.1681 - Control strategy: Lead.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Lead. 52.1681 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) New York § 52.1681 Control strategy: Lead. As part of the attainment demonstration for lead, the State of New York has committed to rate all...

  10. 40 CFR 52.573 - Control strategy: General.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy: General. 52.573... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Georgia> § 52.573 Control strategy: General. The generic rules and procedures for emission trades (bubbles), submitted on October 27, 1982, by...

  11. 40 CFR 52.378 - Control strategy: PM10

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy: PM10 52.378 Section 52.378 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Connecticut § 52.378 Control strategy: PM10 (a)...

  12. Advanced Control Strategy of DFIG Wind Turbines for Power System Fault Ride Through

    DEFF Research Database (Denmark)

    Yang, Lihui; Xu, Zhao; Ostergaard, Jacob;

    2012-01-01

    This paper presents an advanced control strategy for the rotor and grid side converters of the doubly fed induction generator (DFIG) based wind turbine (WT) to enhance the low-voltage ride-through (LVRT) capability according to the grid connection requirement. Within the new control strategy...... the oscillations in the stator and rotor currents and the DC bus voltage. The effectiveness of the proposed control strategy has been demonstrated through various simulation cases. Compared with conventional crowbar protection, the proposed control method can not only improve the LVRT capability of the DFIG WT......, but also help maintaining continuous active and reactive power control of the DFIG during the grid faults....

  13. Fuzzy Based composition Control of Distillation Column

    Directory of Open Access Journals (Sweden)

    Guru.R

    2013-04-01

    Full Text Available This paper proposed a control scheme based on fuzzy logic for a methanol - water system of bubble cap distillation column. Fuzzy rule base and Inference System of fuzzy (FIS is planned to regulatethe reflux ratio (manipulated variable to obtain the preferred product composition (methanol for a distillation column. Comparisons are made with conventional controller and the results confirmed the potentials of the proposed strategy of fuzzy control.

  14. Partial budget of the discounted annual benefit of mastitis control strategies.

    Science.gov (United States)

    Allore, H G; Erb, H N

    1998-08-01

    The objective of this study was to rank the benefits associated with various mastitis control strategies in simulated herds with intramammary infections caused by Streptococcus agalactiae, Streptococcus spp. other than Strep. agalactiae, Staphylococcus aureus, coagulase-negative staphylococci, and Escherichia coli. The control strategies tested were prevention, vaccination for E. coli, lactation therapy, and dry cow antibiotic therapy. Partial budgets were based on changes caused by mastitis control strategies from the mean values for milk, fat, and protein yields of the control herd and the number of cows that were culled under a fixed mastitis culling criterion. Each annual benefit (dollars per cow per year) of a mastitis control strategy was compared with the revenue for the control herd and was calculated under two different milk pricing plans (3.5% milk fat and multiple-component pricing), three net replacement costs, and three prevalences of pathogen-specific intramammary infection. Twenty replicates of each control strategy were run with SIMMAST (a dynamic discrete event stochastic simulation model) for 5 simulated yr. Rankings of discounted annual benefits differed only slightly according to milk pricing plans within a pathogen group but differed among the pathogen groups. Differences in net replacement costs for cows culled because of mastitis did not change the ranking of control strategies within a pathogen group. Both prevention and dry cow therapy were important mastitis control strategies. For herds primarily infected with environmental pathogens, strategies that included vaccination for mastitis caused by E. coli dominated strategies that did not include vaccination against this microorganism.

  15. Information Feedback Strategies in a Signal Controlled Network with Overlapped Routes

    Institute of Scientific and Technical Information of China (English)

    TIAN Li-Jun; HUANG Hai-Jun; LIU Tian-Liang

    2009-01-01

    We investigate the effects of four different information feedback strategies on the dynamics of traffic, travel-ers' route choice and the resultant system performance in a signal controlled network with overlapped routes.Simulation results given by the cellular automaton model show that the system purpose-based mean velocity feedback strategy and the congestion coefficient feedback strategy have more advantages in improving network utilization efficiency and reducing travelers' travel times. The travel time feedback strategy and the individual purposed-based mean velocity feedback strategy behave slightly better to ensure user equity.

  16. 基于MC9S12XS智能车的控制策略%Control Strategy of Intelligent Vehicle Based on MC9S12XS

    Institute of Scientific and Technical Information of China (English)

    姜培林; 何毅

    2011-01-01

    In this paper, we integrate Freescale Cup National Smart Car competition, using MC9S12XE128 as the core unit for the design and implementation of smart car tracing system based on a CCD sensor, to adopt the method of nonlinear sampling to find out the location and direction of the path. Based on the path information and direction of deviation from nonlinear sampling, to determine the speed control and direction control of smart vehicle.%结合飞思卡尔杯全国智能车比赛,以MC9S 12XE 128为控制核心单元,设计并实现一种基于CCD传感器的智能寻迹小车系统,采用非线性采样方法来找出路径的位置和方向.以非线性采样得到的路径信息和方向偏差,来决定智能车的速度控制和方向控制.

  17. Sustaining an Acquisition-based Growth Strategy

    DEFF Research Database (Denmark)

    Henningsson, Stefan; Toppenberg, Gustav; Shanks, Graeme

    complementarity, c) directing and governing the integration process, and d) post-acquisition evaluation of the achieved integration and proposing ways forward. Using the EA capability in the acquisition process improves Cisco’s ability to rapidly capture value from its acquisitions and to sustain its acquisition......-based growth strategy over time....

  18. Vector Control Based on SVPWM for ACIM

    Directory of Open Access Journals (Sweden)

    Zhu Jun

    2013-05-01

    Full Text Available To solve the large torque ripple and current harmonics, low DC bus voltage problems, a new control strategy is proposed for AC induction motor by using space vector pulse width modulation, so that the static and dynamic performance are improved. The system simulation experiment mode was established based on SVPWM to verify the effectiveness of the system control mode. It is showed that it can reduce the current ripple and torque ripple, improve the utilization of DC bus voltage. It means that the control strategy based SVPWM can improve dynamic and static performance effectively for the ACIM servo system.

  19. Congestion control strategy based on quality of message in DTN%DTN中依据报文质量的拥塞控制策略

    Institute of Scientific and Technical Information of China (English)

    王贵竹; 徐正欢; 李晓峰

    2012-01-01

    为了解决受限网络环境所带来的低的递交率的问题,DTN(Delay Tolerant Networks)通常采用多拷贝路由(multiple-copy routing)机制来实现报文的有效递交.但在实际情况下,网络中节点的缓存是受限的,当网络中的总报文教大于所有节点的缓存容量和时,网络就发生了拥塞.针对网络拥塞,通过计算节点缓存中的报文质量(Quality of Message)以确定报文丢弃的优先级,合理地丢弃报文控制拥塞.仿真结果显示与其他拥塞控制策略相比,该路由策略能得到更好的网络性能.%To solve the problem of low delivery ratio caused by intermittent network, DTN adopt multiple-copy routing to ensure the efficiency of message delivery. But in real situation, because the buffer of the node is limited, the network is congested when the number of message in network is larger than the sum of the buffer of the nodes. To deal with the congestion of the network, this paper drops the messages reasonably by defining the priority of message, and the priority is determined by the quality of the messages in the buffer of the node. The results show that this congestion control strategy can improve the network performance in congestion environment.

  20. Zinc finger artificial transcription factor-based nearest inactive analogue/nearest active analogue strategy used for the identification of plant genes controlling homologous recombination.

    Science.gov (United States)

    Jia, Qi; van Verk, Marcel C; Pinas, Johan E; Lindhout, Beatrice I; Hooykaas, Paul J J; van der Zaal, Bert J

    2013-12-01

    In previous work, we selected a particular transcription factor, designated VP16-HRU, from a pool of zinc finger artificial transcription factors (ZF-ATFs) used for genome interrogation. When expressed in Arabidopsis thaliana under control of the ribosomal protein S5A promoter, the RPS5A::VP16-HRU construct led to a 200- to 300-fold increase in the frequency of somatic intrachromosomal homologous recombination (iHR). Because the expression of each ZF-ATF leads to a large number of transcriptional changes, we designed a strategy employing a collection of structurally similar ZF-ATFs to filter out the transcriptional changes relevant to the phenotype by deep sequencing. In that manner, 30 transcripts were found to be consistently induced in plants with enhanced homologous recombination (HR). For 25 of the cognate genes, their effect on the HR process was assessed using cDNA/gDNA expression constructs. For three genes, ectopic expression indeed led to enhanced iHR frequencies, albeit much lower than the frequency observed when a HR-inducing ZF-ATF was present. Altogether, our data demonstrate that despite the large number of transcriptional changes brought about by individual ZF-ATFs, causal changes can be identified. In our case, the picture emerged that a natural regulatory switch for iHR does not exist but that ZF-ATFs-like VP16-HRU act as an ectopic master switch, orchestrating the timely expression of a set of plant genes that each by themselves only have modest effects, but when acting together support an extremely high iHR frequency.

  1. Paratransgenesis: a promising new strategy for mosquito vector control.

    Science.gov (United States)

    Wilke, André Barretto Bruno; Marrelli, Mauro Toledo

    2015-06-24

    The three main mosquito genera, Anopheles, Aedes and Culex, transmit respectively malaria, dengue and lymphatic filariasis. Current mosquito control strategies have proved unsuccessful, and there still is a substantial number of morbidity and mortality from these diseases. Genetic control methods have now arisen as promising alternative strategies, based on two approaches: the replacement of a vector population by disease-refractory mosquitoes and the release of mosquitoes carrying a lethal gene to suppress target populations. However, substantial hurdles and limitations need to be overcome if these methods are to be used successfully, the most significant being that a transgenic mosquito strain is required for every target species, making genetically modified mosquito strategies inviable when there are multiple vector mosquitoes in the same area. Genetically modified bacteria capable of colonizing a wide range of mosquito species may be a solution to this problem and another option for the control of these diseases. In the paratransgenic approach, symbiotic bacteria are genetically modified and reintroduced in mosquitoes, where they express effector molecules. For this approach to be used in practice, however, requires a better understanding of mosquito microbiota and that symbiotic bacteria and effector molecules be identified. Paratransgenesis could prove very useful in mosquito species that are inherently difficult to transform or in sibling species complexes. In this approach, a genetic modified bacteria can act by: (a) causing pathogenic effects in the host; (b) interfering with the host's reproduction; (c) reducing the vector's competence; and (d) interfering with oogenesis and embryogenesis. It is a much more flexible and adaptable approach than the use of genetically modified mosquitoes because effector molecules and symbiotic bacteria can be replaced if they do not achieve the desired result. Paratransgenesis may therefore become an important integrated

  2. Control Strategies for Guided Collective Motion

    Science.gov (United States)

    2015-01-30

    Proceedings of the American Control Conference , Washington...of multiple robots using a modified Kuramoto model. Proceedings of the American Control Conference , Washington, DC, USA, pages 6138– 6144. 2014 ACODS...L.B. Arranz, A. Seuret, and C.C. de Wit, “Contraction control of a fleet circular formation of AUVs under limited communication range,” Proceedings of the American Control

  3. Improved Control Strategy for Microgrid Ultracapacitor Energy Storage Systems

    Directory of Open Access Journals (Sweden)

    Xiaobo Dou

    2014-12-01

    Full Text Available Ultracapacitors (UCs, with their features of high power density and high current charge-discharge, have become the best choice for dynamic power compensation to improve the stability of microgrids and are increasingly being applied in microgrids. This paper presents the control of an energy storage system (ESS based on ultracapacitors in the context of grid-connected microgrids. The ESS is composed of DC/AC and DC/DC converters tied by a dc link. An improved dynamic model for the ESS is proposed. Based on the proposed model a Proportional-Integral-Resonant (PIR DC link voltage controller is proposed to maintain the DC link voltage through the charging-discharging control of ultracapacitors, capable of working properly under all operating conditions. An extra double frequency component is injected into the UC current by a R controller to dynamically compensate for DC instantaneous power and double frequency AC instantaneous power due to unbalanced grid conditions and disturbances. This feature maintains the DC link voltage constant under unbalanced conditions and increases the degrees of freedom of the DC/AC converter and thus facilitates the application of UCs in microgrids. Simulation and experimental results verify the effectiveness of the proposed control strategy.

  4. Coordinated control strategies for a micro-grid based on droop characteristics%基于下垂特性的微电网协调控制策略研究

    Institute of Scientific and Technical Information of China (English)

    黄秀琼; 高文杰; 井天军; 杨明皓

    2012-01-01

    Micro-grid technology aims to solve the problems caused by the large-scale grid-connected operation of distributed generator, and increase the power supply reliability. The coordinated control strategy of micro-sources is the key for the stability of micro—grids. The generic control method and coordinated control strategy of power electronics interface micro sources are analyzed in detail, and a coordinated control strategy for multi micro-source based on droop characteristics is presented in this paper. Using the feedback system BIBO stability criterion rooted in small gain theorem, the influence of the droop gains on the stability of the micro-grid system is analyzed to develop a way to a droop gain design. The proposed design method is verified by the simulation based on Matlab/Simulink.%微电网技术有助于解决分布式电源大规模接入电网的问题,同时增强用户供电的可靠性,而微网内各微源间的协调控制是微网研究的重点.文章分析了微网中电力电子接口的微源常用控制方法和协调控制结构,基于下垂控制特性提出了微网各微源的协调控制策略;利用互联反馈系统BIBO稳定判据小增益定理,分析了下垂系数对系统稳定性的影响,为下垂系数设计提供了依据,最后对提出的下垂系数设计依据在Matlab/Simulink中进行了仿真验证.

  5. DC Microgrids – Part I: A Review of Control Strategies and Stabilization Techniques

    DEFF Research Database (Denmark)

    Dragicevic, Tomislav; Lu, Xiaonan; Quintero, Juan Carlos Vasquez;

    2016-01-01

    This paper presents a review of control strategies, stability analysis and stabilization techniques for DC microgrids (MGs). Overall control is systematically classified into local and coordinated control levels according to respective functionalities in each level. As opposed to local control...... which relies only on local measurements, some line of communication between units needs to be made available in order to achieve coordinated control. Depending on the communication method, three basic coordinated control strategies can be distinguished, i.e. decentralized, centralized and distributed...... control. Decentralized control can be regarded as an extension of local control since it is also based exclusively on local measurements. In contrast, centralized and distributed control strategies rely on digital communication technologies. A number of approaches to using these three coordinated control...

  6. Real-Time Control Strategy of Elman Neural Network for the Parallel Hybrid Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Ruijun Liu

    2014-01-01

    Full Text Available Through researching the instantaneous control strategy and Elman neural network, the paper established equivalent fuel consumption functions under the charging and discharging conditions of power batteries, deduced the optimal control objective function of instantaneous equivalent consumption, established the instantaneous optimal control model, and designs the Elman neural network controller. Based on the ADVISOR 2002 platform, the instantaneous optimal control strategy and the Elman neural network control strategy were simulated on a parallel HEV. The simulation results were analyzed in the end. The contribution of the paper is that the trained Elman neural network control strategy can reduce the simulation time by 96% and improve the real-time performance of energy control, which also ensures the good performance of power and fuel economy.

  7. Strategies for reward-based crowdfunding campaigns

    DEFF Research Database (Denmark)

    Kraus, Sascha; Richter, Christian; Brem, Alexander

    2016-01-01

    Crowdfunding represents an alternative way of funding entrepreneurial ventures – and is attracting a high amount of interest in research as well as practice. Against this back- ground, this paper analyzes reward-based crowdfunding campaign strategies and their communication tools. To do this, 446...... crowdfunding projects were gathered and empirically analyzed. Three different paths of successful crowdfunding projects could be identified and are described in detail. Practical implications of crowdfunding strategies are derived, and are dependent on the required sales effort and the project added value....... The terms communicator, networker and self-runner are created for this crowdfunding strategy and filled with practi- cal examples. This paper contributes to the literature in different ways: first, it sheds more light on the developing concept of crowdfunding, with an overview of current academic dis...

  8. 基于最佳制动效果的并联式混合动力汽车再生制动控制策略%Regenerative Braking Control Strategy for PHEV Based on Optimal Braking Effect

    Institute of Scientific and Technical Information of China (English)

    高爱云; 邓效忠; 张明柱; 付主木

    2015-01-01

    Based on the principles of the braking force distribution,a regenerative braking control strategy was proposed on the basis of the optimal braking effect and fuzzy control,where mechanical braking could cooperate with regenerative braking and front and rear wheel braking force were distribG uted reasonably.Taking the braking strength and the state of charge of batteries as inputs,and reG garding the expected regenerative braking force as an output,a fuzzy controller was designed.The control strategy designed was simulated from parts performance,braking energy recovery and braking sense compared with the default control strategy in ADVISOR.At the same time,the hardwareintheloop simulation was developed to prove the simulation results in ADVISOR effective.The results show that the control strategy presented can assure the driver of satisfactory braking sense based on the braking stability,and improve energy efficiency at the same time and at last achieve optimal braG king effect.%在遵循制动力分配原则的基础上,提出了基于最佳制动效果和模糊控制的再生制动控制策略,使机械制动和再生制动可以很好地协同工作,实现前后轮制动力合理分配。设计了以制动强度和蓄电池荷电状态为输入变量,以期望再生制动力为输出变量的模糊控制器。利用仿真软件 ADVISOR,对所设计的控制策略进行了部件性能、制动能量回收、制动感觉三方面仿真分析。同时,为验证ADVISOR仿真结果的有效性,搭建了硬件在环仿真实验平台。结果表明,所设计的控制策略在保证汽车制动稳定性的前提下,能够使驾驶员获得满意的制动感觉,同时有效提高了汽车能量利用率,最终达到了最佳制动效果。

  9. Control Strategy of SOC Open-Loop of Hybrid Electric Bus Based on Driving Cycle Prediction%基于道路工况预测混合动力公交车SOC开环控制策略

    Institute of Scientific and Technical Information of China (English)

    朱道伟; 谢辉; 严英

    2012-01-01

    混合动力车辆一般采用基于荷电状态(SOC)闭环的控制策略,对蓄电池组进行频繁充电,使SOC维持在较高水平,影响制动能量的回收,从而导致燃油经济性不理想.为此,利用BP神经网络并结合城市公交运行特点,提出SOC开环控制策略,对公交车未来站点间的运行工况进行预测,减少蓄电池组的充电次数,降低蓄电池组的荷电状态.试验表明,采用该控制策略可以显著降低电池组充电时间和次数,有利于制动能量的回收,百公里油耗降低了3%.%The conventional strategy of hybrid electric vehicle was based on the state of charge (SOC) closed-loop which charged the battery frequently to sustain a high-level SOC and decreased the fuel efficiency because the energy from the regenerative braking couldn't be stored any more. SOC open-loop control strategy was proposed using the BP neural network and considering the trait of city bus to predict the next driving cycles between two stops in short future. Experiment result shows that the control strategy is useful to decrease charging times and time-period, which improve fuel efficiency by 3% higher than the vehicle on the route with the control strategy of SOC closed-loop because of enhanced regenerative braking energy.

  10. 基于混合策略博弈的预防控制策略匹配方法%A Strategy-matching Method for Transient Precaution Control Based on Game Theory

    Institute of Scientific and Technical Information of China (English)

    邵振国; 邱凌

    2013-01-01

    An online strategy-matching method for transient precaution control based on game theory is proposed,which regards the contingencies as the strategy of a virtual player and the control actions as that of a dispatcher.The payoff function is defined as the product of variation of stability margin and correction factors of strategy indicating the cost of control action and the influence of the changing environment on contingency,respectively.The method for obtaining Nash equilibrium is given by transforming the gaming model into a dual linear programming model,while the strategy with maximum expected revenue is selected as the precaution action.Finally,the method is verified effective on a New England test system.%以预决策控制策略集和预想事故集作为博弈策略集,以稳定裕度变化作为收益,并引入外界环境影响因子、控制代价及协调控制因子,建立了一种匹配最佳预防控制措施的混合策略博弈模型。将博弈问题求解转化为对偶线性规划问题,给出了 Nash 均衡的求解方法,并选择 Nash 均衡解中期望收益最大的控制策略作为预防控制策略。给出了新英格兰系统的仿真分析算例,验证了方法的有效性。

  11. 仿生六足机器人基于足力分布的位姿调整策略%Posture control strategy based on force distribution for bionic six-legged robot

    Institute of Scientific and Technical Information of China (English)

    刘海清; 刘玉斌; 张赫; 陈杰; 赵杰

    2012-01-01

    针对六足机器人非结构化地形稳定步行问题,研究了基于足力分布的位姿调整策略.通过力学分析建立了机器人任意步态模式下的足力分布模型,获得足底受力的平衡关系;采用重心位置调整策略实现了机器人步行过程中的位姿优化,来提高步行稳定性;并且建立了虚拟悬挂模型,采用足力补偿的方法对外界的扰动进行抑制,进一步提高机器人步行的稳定性.通过仿真验证了该调整策略对提高机器人步行稳定裕度的有效性.%This paper proposed a posture control strategy based on force distribution for the purpose of keeping the posture stability of six - legged robot when the robot was walking on irregular terrain. This strategy considered of establishing the force distribution model on any gait patterns to obtain the balance relationship of plantar forces, and adjusted COG (center of gravity) to achieve optimal posture control. Applied force compensation on the basis of a virtual suspension model to achieve disturbance rejection. This strategy could effectively improve the walking stability of robot on irregular terrain. Adams simulations verified the effectiveness of the control strategy to improve the robot walking stability margin.

  12. Predictive Current Control Strategy Based on ADALINE for Active Power Filter%基于ADALINE的有源电力滤波器预测电流控制策略

    Institute of Scientific and Technical Information of China (English)

    章兢; 于晶荣

    2009-01-01

    为有效补偿有源电力滤波器(APF)的控制延时, 提出一种基于自适应线性神经元(ADALINE)的APF预测电流控制策略.该策略通过ADALINE预测下一控制周期的参考电流, 根据两相静止坐标系下APF系统模型确定参考电压, 利用空间矢量脉宽调制(SVPWM)方法, 使APF输出电流快速、准确地跟踪参考电流.仿真与APF样机上的实际运行结果表明, 和采用传统无预测算法的SVPWM方法相比, 采用本文提出的预测电流控制策略, APF的稳态补偿精度和动态跟踪性能均明显提高.%In order to compensate control delay of active power filter (APF), a predictive current control strategy based on ADAptive LInear NEuron (ADALINE) for three-phase APF is proposed. Reference compensation current for next control cycle is calculated by current predictive algorithm based on ADALINE, and reference voltage is determined according to APF mathematical model in two-phase static coordinate system. The output current of APF can track to reference current quickly and exactly by space vector pulse width modulation (SVPWM) method. Simulation and experimental results on APF prototype demonstrate that, compared with APF of SVPWM control without predictive algorithm, APF with predictive current control strategy based on ADALINE has higher steady state compensation accuracy and better dynamic performance.

  13. Environmental management: a re-emerging vector control strategy.

    Science.gov (United States)

    Ault, S K

    1994-01-01

    Vector control may be accomplished by environmental management (EM), which consists of permanent or long-term modification of the environment, temporary or seasonal manipulation of the environment, and modifying or changing our life styles and practices to reduce human contact with infective vectors. The primary focus of this paper is EM in the control of human malaria, filariasis, arboviruses, Chagas' disease, and schistosomiasis. Modern EM developed as a discipline based primarily in ecologic principles and lessons learned from the adverse environmental impacts of rural development projects. Strategies such as the suppression of vector populations through the provision of safe water supplies, proper sanitation, solid waste management facilities, sewerage and excreta disposal systems, water manipulation in dams and irrigation systems, vector diversion by zooprophylaxis, and vector exclusion by improved housing, are discussed with appropriate examples. Vectors of malaria, filariasis, Chagas' disease, and schistosomiasis have been controlled by drainage or filling aquatic breeding sites, improved housing and sanitation, the use of expanded polystyrene beads, zooprophylaxis, or the provision of household water supplies. Community participation has been effective in the suppression of dengue vectors in Mexico and the Dominican Republic. Alone or combined with other vector control methods, EM has been proven to be a successful approach to vector control in a number of places. The future of EM in vector control looks promising.

  14. How Life Experience Shapes Cognitive Control Strategies: The Case of Air Traffic Control Training.

    Directory of Open Access Journals (Sweden)

    Sandra Arbula

    Full Text Available Although human flexible behavior relies on cognitive control, it would be implausible to assume that there is only one, general mode of cognitive control strategy adopted by all individuals. For instance, different reliance on proactive versus reactive control strategies could explain inter-individual variability. In particular, specific life experiences, like a highly demanding training for future Air Traffic Controllers (ATCs, could modulate cognitive control functions. A group of ATC trainees and a matched group of university students were tested longitudinally on task-switching and Stroop paradigms that allowed us to measure indices of cognitive control. The results showed that the ATCs, with respect to the control group, had substantially smaller mixing costs during long cue-target intervals (CTI and a reduced Stroop interference effect. However, this advantage was present also prior to the training phase. Being more capable in managing multiple task sets and less distracted by interfering events suggests a more efficient selection and maintenance of task relevant information as an inherent characteristic of the ATC group, associated with proactive control. Critically, the training that the ATCs underwent improved their accuracy in general and reduced response time switching costs during short CTIs only. These results indicate a training-induced change in reactive control, which is described as a transient process in charge of stimulus-driven task detection and resolution. This experience-based enhancement of reactive control strategy denotes how cognitive control and executive functions in general can be shaped by real-life training and underlines the importance of experience in explaining inter-individual variability in cognitive functioning.

  15. Research of Control Strategy of Induction Motor Based on Sliding Mode Variable Structure%基于滑模变结构的感应电动机控制策略研究

    Institute of Scientific and Technical Information of China (English)

    黄文涛

    2011-01-01

    Induction motor is a high-level,non-linear,strong coupled and multi-variable system. When if s running,its parameters are influenced by temperature and load and caused the motor to run into unstable region. To adapt to its non-linear system property,a control strategy based on sliding mode variable structure was proposed. Sliding surface was established corresponding to current,rotate speed,flux error,variable structure controller of each link was constructed,and self-adaptive control law was derived. The simulation results showed that the control strategy has effectiveness and feasibility.%感应电动机是一个高阶、非线性、强耦合的多变量系统,在运行的过程中参数易受温度、负载变化的影响,会造成电动机进入不稳定区域运行.为了适应系统的非线性特性,提出了一种基于滑模变结构的控制策略.该策略对电流、转速、磁链误差分别建立滑模面,构造出各环节变结构控制器,并推导出自适应控制律.仿真结果证明了控制策略的有效性和可行性.

  16. Strategy for ecologic control in fighting Varroa destructor

    Directory of Open Access Journals (Sweden)

    Stanimirović Zoran

    2007-01-01

    Full Text Available The ectoparasite Varroa destructor is one of the most wide-spread parasites of the honey bee, which is increasing its resistence to traditional synthetic acaricides more and more with each year. New regulations on quality of the European Union ban the presence of residue in bee products, which rules out the use of chemical means in the course of the honey harvest. The concept of ecologic control of Varroa destructor in honey bee colonies implies the complementary use of adequate biotechnical and biophysical measures and treatments using preparations based on etheric oils and organic acids. The combination of these treatments according to the presented strategy makes it possible to keep varroasis under control.

  17. A controllable stitch layout strategy for random needle embroidery

    Institute of Scientific and Technical Information of China (English)

    Jie ZHOU; Zheng-xing SUN; Ke-wei YANG

    2014-01-01

    Random needle embroidery (RNE) is a graceful art enrolled in the world intangible cultural heritage. In this paper, we study the stitch layout problem and propose a controllable stitch layout strategy for RNE. Using our method, a user can easily change the layout styles by adjusting several high-level layout parameters. This approach has three main features:firstly, a stitch layout rule containing low-level stitch attributes and high-level layout parameters is designed;secondly, a stitch neighborhood graph is built for each region to model the spatial relationship among stitches;thirdly, different stitch attributes (orientations, lengths, and colors) are controlled using different reaction-diffusion processes based on a stitch neighborhood graph. Moreover, our method supports the user in changing the stitch orientation layout by drawing guide curves interactively. The experimental results show its capability for reflecting various stitch layout styles and flexibility for user interaction.

  18. Backstepping Strategy for Induction Motor Control

    DEFF Research Database (Denmark)

    Rasmussen, Henrik; Vadstrup, P.; Børsting, H.

    2000-01-01

    Using backstepping, which is a recursive nonlinear design method, a novel approach to control of induction motors is developed. The resulting scheme leads to a nonlinear controller for the torque and the amplitude of the field. A combination of nonlinear damping and observer backstepping with a s......Using backstepping, which is a recursive nonlinear design method, a novel approach to control of induction motors is developed. The resulting scheme leads to a nonlinear controller for the torque and the amplitude of the field. A combination of nonlinear damping and observer backstepping...... with a simple flux observer is used in the design. Assuming known motor parameters the design achieves stability with guaranteed region of attraction. It is also shown how a conventional field oriented controller may be obtained by omitting parts of the nonlinear controller....

  19. Control Strategies of an Inverted Pendulum.

    Science.gov (United States)

    1981-09-01

    AND PENDULUM --------- 12 2 FULL STATE VARIABLE FEEDBACK CONTROL SYSTEM - 31 3 CART QUARTER VIEW --------------------------- 34 4 CART TOP VIEW...system by moving the closed-loop poles to proper locations in the left-half plane. A feedback control system is one which attempts to main- tain a...pendulum angle oscillates on either side of zero. 30 x x x3 x 3 Figure 2. FULL STATE VARIABLE FEEDBACK CONTROL SYSTEM 31- IV. CONSTRUCTION OF INVERTED

  20. Review of control strategies for robotic movement training after neurologic injury

    Directory of Open Access Journals (Sweden)

    Reinkensmeyer David J

    2009-06-01

    Full Text Available Abstract There is increasing interest in using robotic devices to assist in movement training following neurologic injuries such as stroke and spinal cord injury. This paper reviews control strategies for robotic therapy devices. Several categories of strategies have been proposed, including, assistive, challenge-based, haptic simulation, and coaching. The greatest amount of work has been done on developing assistive strategies, and thus the majority of this review summarizes techniques for implementing assistive strategies, including impedance-, counterbalance-, and EMG- based controllers, as well as adaptive controllers that modify control parameters based on ongoing participant performance. Clinical evidence regarding the relative effectiveness of different types of robotic therapy controllers is limited, but there is initial evidence that some control strategies are more effective than others. It is also now apparent there may be mechanisms by which some robotic control approaches might actually decrease the recovery possible with comparable, non-robotic forms of training. In future research, there is a need for head-to-head comparison of control algorithms in randomized, controlled clinical trials, and for improved models of human motor recovery to provide a more rational framework for designing robotic therapy control strategies.

  1. Backstepping Strategy for Induction Motor Control

    DEFF Research Database (Denmark)

    Rasmussen, Henrik; Vadstrup, P.; Børsting, H.

    2000-01-01

    Using backstepping, which is a recursive nonlinear design method, a novel approach to control of induction motors is developed. The resulting scheme leads to a nonlinear controller for the torque and the amplitude of the field. A combination of nonlinear damping and observer backstepping...... with a simple flux observer is used in the design. Assuming known motor parameters the design achieves stability with guaranteed region of attraction. It is also shown how a conventional field oriented controller may be obtained by omitting parts of the nonlinear controller....

  2. Backstepping Strategy for Induction Motor Control

    DEFF Research Database (Denmark)

    Rasmussen, Henrik; Vadstrup, P.; Børsting, H.

    2000-01-01

    Using backstepping, which is a recursive nonlinear design method, a novel approach to control of induction motors is developed. The resulting scheme leads to a nonlinear controller for the torque and the amplitude of the field. A combination of nonlinear damping and observer backstepping with a s......Using backstepping, which is a recursive nonlinear design method, a novel approach to control of induction motors is developed. The resulting scheme leads to a nonlinear controller for the torque and the amplitude of the field. A combination of nonlinear damping and observer backstepping...

  3. Strategy optimization for controlled Markov process with descriptive complexity constraint

    Institute of Scientific and Technical Information of China (English)

    JIA QingShan; ZHAO QianChuan

    2009-01-01

    Due to various advantages in storage and Implementation,simple strategies are usually preferred than complex strategies when the performances are close.Strategy optimization for controlled Markov process with descriptive complexity constraint provides a general framework for many such problems.In this paper,we first show by examples that the descriptive complexity and the performance of a strategy could be Independent,and use the F-matrix in the No-Free-Lunch Theorem to show the risk that approximating complex strategies may lead to simple strategies that are unboundedly worse in cardinal performance than the original complex strategies.We then develop a method that handles the descriptive complexity constraint directly,which describes simple strategies exactly and only approximates complex strategies during the optimization.The ordinal performance difference between the resulting strategies of this selective approximation method and the global optimum is quantified.Numerical examples on an engine maintenance problem show how this method Improves the solution quality.We hope this work sheds some insights to solving general strategy optimization for controlled Markov procase with descriptive complexity constraint.

  4. A novel and rapid HPGPC-based strategy for quality control of saccharide-dominant herbal materials: Dendrobium officinale, a case study.

    Science.gov (United States)

    Xu, Jun; Li, Song-Lin; Yue, Rui-Qi; Ko, Chun-Hay; Hu, Jiang-Miao; Liu, Jing; Ho, Hing-Man; Yi, Tao; Zhao, Zhong-Zhen; Zhou, Jun; Leung, Ping-Chung; Chen, Hu-Biao; Han, Quan-Bin

    2014-10-01

    Qualitative and quantitative characterization of natural saccharides, especially polysaccharides, in herb materials remains a challenge due to their complicated structures and high macromolecular masses. Currently available methods involve time-consuming and complicated operations, and present poor specificity. Here, a novel and rapid high-performance gel permeation chromatography (HPGPC)-based approach is described for quality assessment of saccharide-dominant herbal materials by simultaneous qualitative and quantitative analysis of saccharide components. Dendrobium officinale, one of the rarest tonic herbs worldwide, was employed as the model herb in this study. First, a HPGPC fingerprint based on the molecular weight distribution of its carbohydrate components was established for qualitative identification of D. officinale. Then, HPGPC-guided dominant holistic polysaccharide marker was separated using ultra-filtration followed by HPGPC determination for quantitative evaluation of D. officinale. The experimental results suggest that this method is more efficient, stable, and convenient compared with the currently available methods for authentication and quality evaluation of D. officinale, and we expect the method will have similar advantages when used for quality control of other saccharide-dominant herbal materials and products.

  5. Health benefit modelling and optimization of vehicular pollution control strategies

    Science.gov (United States)

    Sonawane, Nayan V.; Patil, Rashmi S.; Sethi, Virendra

    2012-12-01

    This study asserts that the evaluation of pollution reduction strategies should be approached on the basis of health benefits. The framework presented could be used for decision making on the basis of cost effectiveness when the strategies are applied concurrently. Several vehicular pollution control strategies have been proposed in literature for effective management of urban air pollution. The effectiveness of these strategies has been mostly studied as a one at a time approach on the basis of change in pollution concentration. The adequacy and practicality of such an approach is studied in the present work. Also, the assessment of respective benefits of these strategies has been carried out when they are implemented simultaneously. An integrated model has been developed which can be used as a tool for optimal prioritization of various pollution management strategies. The model estimates health benefits associated with specific control strategies. ISC-AERMOD View has been used to provide the cause-effect relation between control options and change in ambient air quality. BenMAP, developed by U.S. EPA, has been applied for estimation of health and economic benefits associated with various management strategies. Valuation of health benefits has been done for impact indicators of premature mortality, hospital admissions and respiratory syndrome. An optimization model has been developed to maximize overall social benefits with determination of optimized percentage implementations for multiple strategies. The model has been applied for sub-urban region of Mumbai city for vehicular sector. Several control scenarios have been considered like revised emission standards, electric, CNG, LPG and hybrid vehicles. Reduction in concentration and resultant health benefits for the pollutants CO, NOx and particulate matter are estimated for different control scenarios. Finally, an optimization model has been applied to determine optimized percentage implementation of specific

  6. Storage Management Strategy of Flash-Based Platform

    Institute of Scientific and Technical Information of China (English)

    WANG Taiyong; ZHAO Li; HU Shiguang; WANG Tao

    2009-01-01

    Storage management strategy can be expressed by a file system. Commercial file system for embedded application is generally complicated and resource wasted. In this paper, a specified file system adapted to embedded system with flash-based memory is developed. To guarantee the average usage of flash storage sectors, the strategy of wear leveling and adaptive damage management is introduced, in which a dynamic storage space management mode and the strategy of first in first out (FIFO) are adopted. Moreover, the strategy of redundancy design and fast-calculation and tracing is also adopted to extend the life of kernel sector, which can guarantee the reliable ser-vice of system booting. The practical application in an embedded CNC (computerized numerical control) platform proves that the file system has effective performance. Furthermore, the flash file system can be transplanted to dif-ferent embedded platforms by changing a few bottom hardware parameters with universality.

  7. Implementation of an Open-Loop Rule-Based Control Strategy for a Hybrid-Electric Propulsion System On a Small RPA

    Science.gov (United States)

    2011-03-01

    controlling a system. Hagen and Demuth describe the neural network controller as a function approximator [38]. In this case of a neural network, the...Martin T. Hagan and Howard B. Demuth , "Neural Networks for Control," in American Control Conference, San Diego, 1999. [39] Joseph Matthews

  8. Fuzzy Control Strategy of Battery Management for PHEV during Regenerative Braking

    Directory of Open Access Journals (Sweden)

    Zhumu Fu

    2014-01-01

    Full Text Available Based on analyzing the structure of Parallel Hybrid Electric Vehicle (PHEV and its operation during regenerative braking, a fuzzy control strategy of battery management is proposed. Firstly, the state of charging is estimated by establishing the mathematical relationship between open circuit voltage and the internal resistance model. Secondly, the fuzzy logic controller is designed in regenerative braking system. Finally, by modeling and simulation in ADVISOR, it is shown that the rate of energy recovery with the fuzzy control strategy is increased by 12.3, 18.3 and 7.6%, respectively in three different driving cycles, compared with the benchmark control strategy in the same driving cycles.

  9. 基于振荡能量流的双馈风力发电系统动态稳定控制%A Dynamic Stability Control Strategy of Doubly-Fed Wind Power System Based on Transient Energy Flow

    Institute of Scientific and Technical Information of China (English)

    周香珍; 张顺

    2015-01-01

    提出了一种改善双馈风电场并网系统动态稳定性的控制策略。系统的振荡能量和暂态能量具有一致性,消耗振荡能量的元件能够加速系统不平衡能量的衰减,具有正阻尼。以此为基础,研究了以消耗振荡能量为目标的双馈风电场动态稳定控制方法,并讨论了机组运行极限对控制效果的影响,分析了风电场无功补偿的必要性。控制策略利用双馈风电机组快速有功、无功调节特性,暂存系统不平衡能量,并为系统提供无功补偿,改善系统的动态响应,提高系统稳定性。在DigSILENT/Power Factory中进行了仿真分析,验证了所提出控制策略的有效性及其对电网稳定性的贡献。%A novel control strategy to enhance the dynamic stability of grid-connected wind farm based on doubly-fed induction generator ( DFIG ) was presented. The oscillation energy of system was consistent with its transient energy,the element dissipating energy had positive contribution to the attenuation of unbalancing energy and had positive damping. Then a dynamic stability control strategy based on oscillation energy consumption was studied, the impacts of DFIG operation limits on the control were also discussed, and analyzing the necessity of reactive power compensation for wind farm. The control strategy storage unbalanced energy temporarily and provided fast reactive power compensation by making use of the DFIG fast active and reactive power regulation characteristic, it could improve the dynamic stability of the system. A testing system including a DFIG-based wind farm was realized using DigSILENT/Power Factory, the strategy validation and the contribution to power system stability enhancement were verified by simulation.

  10. Research on control strategy for battery system of photovoltaic power system based on bi-directional DC/DC converter%基于双向变换器的光伏储能控制策略研究

    Institute of Scientific and Technical Information of China (English)

    李鑫; 解璞

    2016-01-01

    独立光伏系统中,储能环节起到平衡功率、稳定系统的关键作用,而合理的控制策略能将储能系统与光伏阵列有机地结合起来,双向 DC/DC变换器正是完成此目标的桥梁。本文在对已有的双向 DC/DC变换器进行优化设计的基础上,提出了一种兼顾电池电性能与系统稳定性的储能系统控制策略。在 Matlab仿真环境下搭建了带有双向 DC/DC变换器的独立光伏系统模型,并对储能系统的工作情况进行仿真,验证了变换器拓扑结构与储能控制策略的合理性。%The independent photovoltaic system needs energy storage in order to balance the power and improve its stability of power generation. A scientiifc control strategy can combine the PV cells with the battery system organically. The bi-directional DC/DC converter can be the bridge to achieve this target. This paper presents a control strategy which takes account of battery electrical performance and system stability based on optimization on the circuit topology of bi-directional DC/DC already underway. Moreover, the charge and discharge circuit based on bi-directional DC/DC converter and an integral independent PV power system are built with Matlab. The simulation results show the correctness of the charge and discharge circuit topology and control strategy.

  11. Energy storage system control strategies for power distribution systems

    Directory of Open Access Journals (Sweden)

    Areewan Kajorndech

    2015-03-01

    Full Text Available Energy storage systems have been widely employed to attain several benefits, such as reliability improvement, stabilization of power systems connected with renewable energy resources, economic benefits and etc. To achieve the above objectives, the appropriate and effective control strategies for energy storage systems are needed to be developed. This research proposes energy storage system control strategies for power distribution systems equipped with a limited size of energy storage system in order to improve reliability and save energy costs by determining an optimal charging schedule of the energy storage system. Simulation results demonstrate the benefits of energy storage system applications under the different control strategies.

  12. A Low Voltage Ride Through Control Strategy for PMSG Based on Electromechanical Energy Storage%基于机电储能的永磁同步发电机低电压穿越控制策略

    Institute of Scientific and Technical Information of China (English)

    田野; 王冕; 张艺枥; 李军; 杨恩星; 陈国柱

    2012-01-01

    This paper summarizes the existing low voltage ride through(LVRT) methods from power flow prospective,and proposes a LVRT control strategy based on the electromechanical energy storage.The generator-side converter maintains DC-link voltage while the grid-side converter tracks the maximum power point of wind energy.This control strategy combines braking resistor with greatly reduced cooling requirements and variable-pitch structure technology,can make full use of the wind turbines' inertial characteristics to store the imbalanced energy and realize LVRT smoothly,without increasing control complexity and system costs significantly.The correctness and validity of this LVRT control strategy is verified through MATLAB simulation of a 1.5 MW permanent magnet synchronous generator(PMSG) wind generation system.%从功率流向角度对已有低电压穿越(LVRT)方法进行归纳总结,在此基础上提出一种LVRT控制策略:基于机电储能,利用机侧变流器稳定直流母线电压,网侧变流器实现最大风能跟踪。该控制策略结合散热要求大大降低的制动电阻与变桨距调节技术,可以在不增加控制复杂度、不显著增加系统成本的情况下,充分利用风电机组惯性,存储电网电压跌落时系统的不平衡能量,平稳实现LVRT。通过对1.5MW永磁直驱风电系统的MATLAB仿真,验证了所提出的LVRT控制策略的正确性和有效性。

  13. Preschool Power Play: Resource Control Strategies Associated with Health

    Directory of Open Access Journals (Sweden)

    Amber R. Massey

    2014-01-01

    Full Text Available Background. This exploratory study uses a multimethod approach to examine the relationship between social strategy usage and overall health in preschool children. Methods. Children's temperament, social strategies, and health assessments were obtained via reported behavior from parents and teachers. In addition, children's use of prosocial and coercive strategies was observed and recorded via one-way windows in the preschool facility. Results. Results revealed that the temperament characteristic of effortful control was related to the observed use of coercive strategies and that coercive strategies were not observed by teachers, who viewed these children as primarily prosocial. The reported use of both coercive and prosocial strategies was also related to decrease in illness. Conclusion. These findings in relation to previous work suggest that using both prosocial and coercive strategies can elevate status as well as maintain health even in young children.

  14. Control strategies and experimental verifications of the electromagnetic mass damper system for structural vibration control

    Institute of Scientific and Technical Information of China (English)

    Zhang Chunwei; Ou Jinping

    2008-01-01

    The electromagnetic mass damper (EMD) control system, as an innovative active control system to reducestructural vibration, offers many advantages over traditional active mass driver/damper (AMD) control systems. In this paper,studies of several EMD control strategies and bench-scale shaking table tests of a two-story model structure are described.First, two structural models corresponding to uncontrolled and Zeroed cases are developed, and parameters of these modelsare validated through sinusoidal sweep tests to provide a basis for establishing an accurate mathematical model for furtherstudies. Then, a simplified control strategy for the EMD system based on the pole assignment control algorithm is proposed.Moreover, ideal pole locations are derived and validated through a series of shaking table tests. Finally, three benchmarkearthquake ground motions and sinusoidal sweep waves are imposed onto the structure to investigate the effectiveness andfeasibility of using this type of innovative active control system for structural vibration control. In addition, the robustnessof the EMD system is examined. The test results show that the EMD system is an effective and robust system for the controlof structural vibrations.

  15. The Modeling Strategies for Open Software Architecture of Robot Controller

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Although the modeling technologies for open robot controllers have been discussed widely, not much literature is devoted to the actual general modeling principles and strategies. The reason is that many researches focus on specific application fields. This paper accommodates for this lacuna and provides some general modeling principles and strategies. At last, the actual new modeling method -Hierarchical Object-Oriented Petri net (HOONet) which has been proved to be an effective modeling methodology, is used to illustrate the modeling strategies.

  16. Discrete Current Control Strategy of Permanent Magnet Synchronous Motors

    Directory of Open Access Journals (Sweden)

    Yan Dong

    2013-01-01

    Full Text Available A control strategy of permanent magnet synchronous motors (PMSMs, which is different from the traditional vector control (VC and direct torque control (DTC, is proposed. Firstly, the circular rotating magnetic field is analyzed on the simplified model and discredited into stepping magnetic field. The stepping magnetomotive force will drive the rotor to run as the stepping motor. Secondly, the stator current orientation is used to build the control model instead of rotor flux orientation. Then, the discrete current control strategy is set and adopted in positioning control. Three methods of the strategy are simulated in computer and tested on the experiment platform of PMSM. The control precision is also verified through the experiment.

  17. Optimal Control Strategies in Delayed Sharing Information Structures

    CERN Document Server

    Nayyar, Ashutosh; Teneketzis, Demosthenis

    2010-01-01

    The $n$-step delayed sharing information structure is investigated. This information structure comprises of $K$ controllers that share their information with a delay of $n$ time steps. This information structure is a link between the classical information structure, where information is shared perfectly between the controllers, and a non-classical information structure, where there is no "lateral" sharing of information among the controllers. Structural results for optimal control strategies for systems with such information structures are presented. A sequential methodology for finding the optimal strategies is also derived. The solution approach provides an insight for identifying structural results and sequential decomposition for general decentralized stochastic control problems.

  18. Drinker prototype alteration and cue reminders as strategies in a tailored Web-based intervention reducing adults' alcohol consumption: Randomized controlled trial

    NARCIS (Netherlands)

    B. van Lettow (Britt); H. de Vries (Hein); A. Burdorf (Alex); B.J.F. Boon (Brigitte); P. van Empelen (Pepijn)

    2015-01-01

    textabstractBackground: Excessive alcohol use is a prevalent and worldwide problem. Excessive drinking causes a significant burden of disease and is associated with both morbidity and excess mortality. Prototype alteration and provision of a cue reminder could be useful strategies to enhance the eff

  19. Multicriteria Evaluation of Classical Swine Fever Control Strategies Using the Choquet Integral.

    Science.gov (United States)

    Brosig, J; Traulsen, I; Krieter, J

    2016-02-01

    An outbreak of the highly contagious animal disease classical swine fever (CSF) requires the selection of an optimal control strategy. The choice of a control strategy is a decision process depending on different aspects. Besides epidemiology, economic and ethical/social aspects must be taken into account. In this study, multicriteria decision-making (MCDM) was used to evaluate six control strategies for two regions with different farm densities. A strategy including only the minimum EU control measures and the traditional control strategy based on preventive culling were compared to alternative control strategies using emergency vaccination and/or rapid PCR testing ('emergency vaccination', 'test to slaughter', 'test to control' and 'vaccination in conjunction with rapid testing'). The MACBETH approach was used in order to assess the three main criteria (epidemiology, economics and ethical/social aspects). Subcriteria with both quantitative and qualitative performance levels were translated into a normalized scale. The Choquet integral approach was adopted to obtain a ranking of the six CSF control strategies based on the three main criteria, taking interactions into account. Three different rankings of the importance of the main criteria, which were to reflect the potential perceptions of stakeholders, were examined. Both the region under investigation and the ranking of the main criteria had an influence on the 'best' choice. Alternative control strategies were favourable to the minimum EU control and the traditional control measures independent of the farm density. Because the choice of the 'best' control strategy does not solely depend on the epidemiological efficiency, MCDM can help to find the best solution. Both MACBETH and the Choquet integral approach are feasible MCDM approaches. MACBETH only needs a qualitative evaluation and is therefore a comparatively intuitive approach. The Choquet integral does not only take the importance of the criteria into

  20. Strategy-based listening and pragmatic comprehension

    Directory of Open Access Journals (Sweden)

    Corsetti, Cristiane Ruzicki

    2014-01-01

    Full Text Available This article addresses the role of strategy-based listening as an alternative methodological approach to develop pragmatic comprehension in L2 contexts. Pragmatic comprehension refers to the understanding of speech acts and conversational implicatures. Listening comprehension comprises both bottom-up and top-down processes. Strategy-based listening encompasses the activation of pragmatic knowledge through pre-listening activities and the development of specific listening micro-skills. An empirical project which included a classroom project carried out with a group of eight learners preparing for the IELTS examination in 2009 corroborated the following assumptions: in order to achieve listening proficiency, learners need practice in making inferences as semantic and pragmatic inferences are embedded in verbal communication; semantic and pragmatic aspects affecting the meaning of utterances can be highlighted via comprehension activities focusing on specific listening subskills. The results of the classroom project suggested that strategy-based listening is potentially capable of directly enhancing pragmatic comprehension but were inconclusive with regards to pragmatic production

  1. 40 CFR 52.2235 - Control strategy: Ozone.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Ozone. 52.2235... strategy: Ozone. (a) Determination—EPA is determining that, as of August 8, 1995, the Nashville ozone nonattainment area has attained the ozone standard and that the reasonable further progress and...

  2. 40 CFR 52.2088 - Control strategy: Ozone.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Ozone. 52.2088... strategy: Ozone. (a) Revisions to the State Implementation Plan submitted by the Rhode Island Department of...) of the Clean Air Act, for the Providence serious ozone nonattainment area. (b) Approval—Revisions...

  3. 40 CFR 52.1129 - Control strategy: Ozone.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Ozone. 52.1129... strategy: Ozone. (a) Revisions to the State Implementation Plan submitted by the Massachusetts Department...) and 182(c)(2)(B) of the Clean Air Act for the Springfield, Massachusetts serious ozone...

  4. 40 CFR 52.2275 - Control strategy and regulations: Ozone.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy and regulations: Ozone... strategy and regulations: Ozone. (a) Section 510.3 of revised Regulation V, which was submitted by the..., concerning the Victoria County 1-hour ozone maintenance plan. This SIP revision was adopted by TCEQ...

  5. 40 CFR 52.2585 - Control strategy: Ozone.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Ozone. 52.2585... strategy: Ozone. (a) Disapproval—On November 6, 1986, the Wisconsin Department of Natural Resources submitted as a proposed revision to the State's ozone State Implementation Plan a site-specific...

  6. 40 CFR 52.1534 - Control strategy: Ozone.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Ozone. 52.1534... strategy: Ozone. (a) Revisions to the State Implementation Plan submitted by the New Hampshire Department... revisions are for the purpose of satisfying the one-hour ozone attainment demonstration requirements...

  7. 40 CFR 52.1486 - Control strategy: Hydrocarbons and ozone.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Hydrocarbons and ozone. 52.1486 Section 52.1486 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... strategy: Hydrocarbons and ozone. (a) The requirements of subpart G of this chapter are not met since...

  8. A Tool for the Development of Robot Control Strategies

    Directory of Open Access Journals (Sweden)

    Luiz Carlos Figueiredo

    2007-12-01

    Full Text Available In this paper we report as the development of a tool in to develop and set control strategies as a fast and easy way. Additionally, a tricycle robot with two traction motors was built to test the strategies produced with the tool. Experimental tests have shown an advantage in the use of such tool.

  9. The Myriad Strategies for Seeking Control in the Dying Process

    Science.gov (United States)

    Schroepfer, Tracy A.; Noh, Hyunjin; Kavanaugh, Melinda

    2009-01-01

    Purpose: This study explored the role control plays in the dying process of terminally ill elders by investigating the aspects of the dying process over which they seek to exercise control, the strategies they use, and whether they desire to exercise more control. Design and Methods: In-depth face-to-face interviews were conducted with 84…

  10. A Comprehensive LVRT Control Strategy for DFIG Wind Turbines With Enhanced Reactive Power Support

    DEFF Research Database (Denmark)

    Xie, Dongliang; Xu, Zhao; Yang, Lihui;

    2013-01-01

    The paper presents a new control strategy to enhance the ability of reactive power support of a doubly fed induction generator (DFIG) based wind turbine during serious voltage dips. The proposed strategy is an advanced low voltage ride through (LVRT) control scheme, with which a part of the captu......The paper presents a new control strategy to enhance the ability of reactive power support of a doubly fed induction generator (DFIG) based wind turbine during serious voltage dips. The proposed strategy is an advanced low voltage ride through (LVRT) control scheme, with which a part......'s excessive inertia energy into the grid. Based on these designs, the DFIG's reactive power capacity on the stator and the grid side converter is handled carefully to satisfy the new grid code requirements strictly. Simulation studies are presented and discussed....

  11. A Novel Hybrid Safety-control Strategy for a Manipulator

    Directory of Open Access Journals (Sweden)

    Jing Xia

    2014-04-01

    Full Text Available As robots tend to work cooperatively with humans in shared workplaces, safety as regards robot- human interactions has caused a great deal of concern in the robot community, and control strategies have become a hot topic in robotics research. In order to guarantee the robot’s safety and continuous motions, this paper proposes a novel safety-control strategy, which is strictly conservative and which consists of a pre-contact and post-contact safety strategy. We adopt an optimal motion trajectory-planning method, by use of which the jerk, acceleration and velocity of the robot’s motion can be limited and a time-optimal motion can be obtained as a post-contact safety strategy for a position-controlled manipulator. The optimal motion trajectory planning not only reduces the impact forces during the collision period, but also maintains the efficiency of the manipulator and preserves continuous motions. Next, we describe a novel collision detection method as a pre-contact safety strategy to avoid collisions. The method proposed here can compute security warning region to handle the effect of robot motion on collision detection and detect collisions between non-convex polygon soups. Finally, the control strategy is implemented for a 7-DOF humanoid manipulator and the experimental results demonstrate the validity of this novel hybrid safety-control strategy.

  12. 40 CFR 52.1877 - Control strategy: Photochemical oxidants (hydrocarbons).

    Science.gov (United States)

    2010-07-01

    ... oxidants (hydrocarbons). 52.1877 Section 52.1877 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY....1877 Control strategy: Photochemical oxidants (hydrocarbons). (a) The requirements of Subpart G of this... national standard for photochemical oxidants (hydrocarbons) in the Metropolitan Cincinnati...

  13. FACTS device control strategy using PMU

    Directory of Open Access Journals (Sweden)

    Mohd Tauseef Khan

    2016-09-01

    Full Text Available The laying and commissioning of new transmission line is very difficult due to socio-economic problems, like environmental clearances, right of way, etc. Therefore, there is an emphasis on better utilization of available transmission infrastructure. FACTS devices can provide reactive power compensation, transmission capability enhancement, and voltage and stability improvement. FACTS devices operate under the command of system operator who analyses its demand by the data acquired through traditional SCADA system, state estimation algorithms and PMUs. SCADA together with PMU give accurate information about the operational state of power system. This paper proposes a scheme to automate the FACTS devices in collaboration with PMUs in a more efficient way. Highly precised data from PMUs can be fed to intelligent controllers for effective analyzing and automating the FACTS device through control command. Thus, this combination can provide real time control of reactive power, together with enhancement of power handling capability and stability improvement.

  14. Chattering-free fuzzy sliding-mode control strategy for uncertain chaotic systems

    Energy Technology Data Exchange (ETDEWEB)

    Yau, H.-T. [Department of Electrical Engineering, Far-East College, Tainan 744, Taiwan (China)]. E-mail: pan1012@ms52.hinet.net; Chen, C.-L. [Department of Aeronautics and Astronautics, National Cheng Kung University, Tainan, Taiwan (China)

    2006-11-15

    This paper proposes a chattering-free fuzzy sliding-mode control (FSMC) strategy for uncertain chaotic systems. A fuzzy logic control is used to replace the discontinuous sign function of the reaching law in traditional sliding-mode control (SMC), and hence a control input without chattering is obtained in the chaotic systems with uncertainties. Base on the Lyapunov stability theory, we address the design schemes of integration fuzzy sliding-mode control, where the reaching law is proposed by a set of linguistic rules and the control input is chattering free. The Genesio chaotic system is used to test the proposed control strategy and the simulation results show the FSMC not only can control the uncertain chaotic behaviors to a desired state without oscillator very fast, but also the switching function is smooth without chattering. This result implies that this strategy is feasible and effective for chaos control.

  15. Controlling chemical dosing for sulfide mitigation in sewer networks using a hybrid automata control strategy.

    Science.gov (United States)

    Liu, Yiqi; Ganigué, Ramon; Sharma, Keshab; Yuan, Zhiguo

    2013-01-01

    Chemicals such as magnesium hydroxide (Mg(OH)2) and iron salts are widely used to control sulfide-induced corrosion in sewer networks composed of interconnected sewer pipe lines and pumping stations. Chemical dosing control is usually non-automatic and based on experience, thus often resulting in sewage reaching the discharge point receiving inadequate or even no chemical dosing. Moreover, intermittent operation of pumping stations makes traditional control theory inadequate. A hybrid automata-based (HA-based) control method is proposed in this paper to coordinate sewage pumping station operations by considering their states, thereby ensuring suitable chemical concentrations in the network discharge. The performance of the proposed control method was validated through a simulation study of a real sewer network using real sewage flow data. The physical, chemical and biological processes were simulated using the well-established SeweX model. The results suggested that the HA-based control strategy significantly improved chemical dosing control performance and sulfide mitigation in sewer networks, compared to the current common practice.

  16. Modelling 3D control of upright stance using an optimal control strategy.

    Science.gov (United States)

    Qu, Xingda; Nussbaum, Maury A

    2012-01-01

    A 3D balance control model of quiet upright stance is presented, based on an optimal control strategy, and evaluated in terms of its ability to simulate postural sway in both the anterior-posterior and medial-lateral directions. The human body was represented as a two-segment inverted pendulum. Several assumptions were made to linearise body dynamics, for example, that there was no transverse rotation during upright stance. The neural controller was presumed to be an optimal controller that generates ankle control torque and hip control torque according to certain performance criteria. An optimisation procedure was used to determine the values of unspecified model parameters including random disturbance gains and sensory delay times. This model was used to simulate postural sway behaviours characterised by centre-of-pressure (COP)-based measures. Confidence intervals for all normalised COP-based measures contained unity, indicating no significant differences between any of the simulated COP-based measures and corresponding experimental references. In addition, mean normalised errors for the traditional measures were 3D balance control model appears to have the ability to accurately simulate 3D postural sway behaviours.

  17. Energy storage system control strategies for power distribution systems

    OpenAIRE

    Areewan Kajorndech; Dulpichet Rerkpreedapong

    2015-01-01

    Energy storage systems have been widely employed to attain several benefits, such as reliability improvement, stabilization of power systems connected with renewable energy resources, economic benefits and etc. To achieve the above objectives, the appropriate and effective control strategies for energy storage systems are needed to be developed. This research proposes energy storage system control strategies for power distribution systems equipped with a limited size of energy storage system ...

  18. Integrated Control Strategies Supporting Autonomous Functionalities in Mobile Robots

    Science.gov (United States)

    2005-01-01

    Integrated Control Strategies Supporting Autonomous Functionalities in Mobile Robots B. Sightsa, H.R. Everetta, E. Biagtan Pacisa, G. Koguta M...TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Integrated Control Strategies Supporting Autonomous Functionalities in Mobile Robots 5a...calculation methods using encoder counts, wheel radius, and the robot’s wheelbase, as described in Sensors For Mobile Robots [5]. On top of this

  19. On Control Strategies for Responsive Architectural Structures

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Parigi, Dario

    2012-01-01

    The present paper considers control of responsive architectural structures for improvement of structural performance by recognizing changes in their environments and loads, adapting to meet goals, and using past events to improve future performance or maintain serviceability. The general scope of...

  20. 三电平逆变器中点平衡的参数自整定模糊控制%Neutral Point Potential Balance of Three-Level Inverter Based on Parameters Self-tuning Fuzzy Logic Control Strategy

    Institute of Scientific and Technical Information of China (English)

    杜恩利; 何礼高; 李旭; 马彦林

    2011-01-01

    A significant problem with diode neutral point clamped three-level inverter is the fluctuation in the neutral-point voltage.The causes of the neutral point potential unbalance based on space vector pulse width modulation are analyzed. And then a strategy based on parameters self-tuning fuzzy logic control is presented which could solve the problems of some commonly used control strategies. For time-variable nonlinear system,this algorithm has better robustness and adaptability.Also there are small static and dynamic error in controlling of the neutral point voltage.The effectiveness of the proposed control approach is verified by simulation and experimental results.%中点电位平衡对二极管箝位三电平逆变器而言非常重要.在此深入分析了空间矢量调制中引起中点电位偏移的原因,提出了基于参数自整定模糊控制的中点平衡控制策略.该算法对三电平逆变器中点电位这一非线性时变对象有较好的适应性和鲁棒性,其静态及动态误差都能控制在较低范围,达到中点电位平衡的效果.仿真和实验结果证明了该算法的正确性和有效性.

  1. 重复控制的开关磁阻电机转矩脉动抑制策略%Repetitive Control Based Torque Ripple Reduction Strategy for SRM

    Institute of Scientific and Technical Information of China (English)

    刘作军; 常硕; 董砚; 郑易

    2013-01-01

    针对开关磁阻电机在运行中的转矩脉动问题,提出了一种基于重复控制的开关磁阻电机转矩脉动抑制方法.在具有周期性扰动的控制系统中,重复控制把上一周期的偏差和当前的偏差叠加到被控对象进行控制,以达到高精度的控制效果.在此策略基础上,通过转子位置角估算和滞环电流控制,合理调节转矩大小,使电机转矩在运行中平稳过渡,从而达到抑制其转矩脉动的效果.仿真证实该方法能够有效地抑制开关磁阻电机的转矩脉动.%To reduce the torque ripple in switched reluctance motor,a strategy based on repetitive control was proposed.In the system with periodic disturbance,repetitive control can obtain high precision in the way of inputting the sum of error in the present period and the last period.Based on this strategy,the torque of SRM could be adjusted with rotator position and current hysteresis-band control to make the motor running smoothly.And high torque ripple control performance was obtained.Simulation and experiment prove the effect in reducing torque ripple of SRM.

  2. Multi Criteria Decision Making to evaluate control strategies of contagious animal diseases.

    Science.gov (United States)

    Mourits, M C M; van Asseldonk, M A P M; Huirne, R B M

    2010-09-01

    The decision on which strategy to use in the control of contagious animal diseases involves complex trade-offs between multiple objectives. This paper describes a Multi Criteria Decision Making (MCDM) application to illustrate its potential support to policy makers in choosing the control strategy that best meets all of the conflicting interests. The presented application focused on the evaluation of alternative strategies to control Classical Swine Fever (CSF) epidemics within the European Union (EU) according to the preferences of the European Chief Veterinary Officers (CVO). The performed analysis was centred on the three high-level objectives of epidemiology, economics and social ethics. The appraised control alternatives consisted of the EU compulsory control strategy, a pre-emptive slaughter strategy, a protective vaccination strategy and a suppressive vaccination strategy. Using averaged preference weights of the elicited CVOs, the preference ranking of the control alternatives was determined for six EU regions. The obtained results emphasized the need for EU region-specific control. Individual CVOs differed in their views on the relative importance of the various (sub)criteria by which the performance of the alternatives were judged. Nevertheless, the individual rankings of the control alternatives within a region appeared surprisingly similar. Based on the results of the described application it was concluded that the structuring feature of the MCDM technique provides a suitable tool in assisting the complex decision making process of controlling contagious animal diseases.

  3. Hierarchical Control Strategy for the Cooperative Braking System of Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Jiankun Peng

    2015-01-01

    Full Text Available This paper provides a hierarchical control strategy for cooperative braking system of an electric vehicle with separated driven axles. Two layers are defined: the top layer is used to optimize the braking stability based on two sliding mode control strategies, namely, the interaxle control mode and signal-axle control strategies; the interaxle control strategy generates the ideal braking force distribution in general braking condition, and the single-axle control strategy can ensure braking safety in emergency braking condition; the bottom layer is used to maximize the regenerative braking energy recovery efficiency with a reallocated braking torque strategy; the reallocated braking torque strategy can recovery braking energy as much as possible in the premise of meeting battery charging power. The simulation results show that the proposed hierarchical control strategy is reasonable and can adapt to different typical road surfaces and load cases; the vehicle braking stability and safety can be guaranteed; furthermore, the regenerative braking energy recovery efficiency can be improved.

  4. Hierarchical Control Strategy for the Cooperative Braking System of Electric Vehicle

    Science.gov (United States)

    Peng, Jiankun; He, Hongwen; Liu, Wei; Guo, Hongqiang

    2015-01-01

    This paper provides a hierarchical control strategy for cooperative braking system of an electric vehicle with separated driven axles. Two layers are defined: the top layer is used to optimize the braking stability based on two sliding mode control strategies, namely, the interaxle control mode and signal-axle control strategies; the interaxle control strategy generates the ideal braking force distribution in general braking condition, and the single-axle control strategy can ensure braking safety in emergency braking condition; the bottom layer is used to maximize the regenerative braking energy recovery efficiency with a reallocated braking torque strategy; the reallocated braking torque strategy can recovery braking energy as much as possible in the premise of meeting battery charging power. The simulation results show that the proposed hierarchical control strategy is reasonable and can adapt to different typical road surfaces and load cases; the vehicle braking stability and safety can be guaranteed; furthermore, the regenerative braking energy recovery efficiency can be improved. PMID:26236772

  5. Real Time Energy Management Control Strategies for Hybrid Powertrains

    Science.gov (United States)

    Zaher, Mohamed Hegazi Mohamed

    In order to improve fuel efficiency and reduce emissions of mobile vehicles, various hybrid power-train concepts have been developed over the years. This thesis focuses on embedded control of hybrid powertrain concepts for mobile vehicle applications. Optimal robust control approach is used to develop a real time energy management strategy for continuous operations. The main idea is to store the normally wasted mechanical regenerative energy in energy storage devices for later usage. The regenerative energy recovery opportunity exists in any condition where the speed of motion is in opposite direction to the applied force or torque. This is the case when the vehicle is braking, decelerating, or the motion is driven by gravitational force, or load driven. There are three main concepts for regernerative energy storing devices in hybrid vehicles: electric, hydraulic, and flywheel. The real time control challenge is to balance the system power demand from the engine and the hybrid storage device, without depleting the energy storage device or stalling the engine in any work cycle, while making optimal use of the energy saving opportunities in a given operational, often repetitive cycle. In the worst case scenario, only engine is used and hybrid system completely disabled. A rule based control is developed and tuned for different work cycles and linked to a gain scheduling algorithm. A gain scheduling algorithm identifies the cycle being performed by the machine and its position via GPS, and maps them to the gains.

  6. A Comparative Study between Two Control Strategies for Matrix Converter

    Directory of Open Access Journals (Sweden)

    BENDIABDELLAH, A.

    2009-06-01

    Full Text Available The authors compare two control strategies for direct AC-AC matrix converters; namely the Venturini method and the scalar strategy control method. The performance comparison of the two strategies is made under unbalanced distorted torque, rotor speed and stator current operation. The simulation of the three-phase matrix converter feeding an induction motor was accomplished by means of the Matlab/Simulink software. This package makes it possible to simulate the dynamic systems in a simple way and in graphic environment.

  7. Disturbance observer based current controller for vector controlled IM drives

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Dal, Mehmet

    2008-01-01

    In order to increase the accuracy of the current control loop, usually, well known parameter compensation and/or cross decoupling techniques are employed for advanced ac drives. In this paper, instead of using these techniques an observer-based current controller is proposed for vector controlled...... coupling effects and increase robustness against parameters change without requiring any other compensation strategies. The experimental implementation results are provided to demonstrate validity and performance of the proposed control scheme.......In order to increase the accuracy of the current control loop, usually, well known parameter compensation and/or cross decoupling techniques are employed for advanced ac drives. In this paper, instead of using these techniques an observer-based current controller is proposed for vector controlled...

  8. Mesh refinement strategy for optimal control problems

    OpenAIRE

    Paiva, Luis Tiago; Fontes, Fernando,

    2013-01-01

    International audience; Direct methods are becoming the most used technique to solve nonlinear optimal control problems. Regular time meshes having equidistant spacing are frequently used. However, in some cases these meshes cannot cope accurately with nonlinear behavior. One way to improve the solution is to select a new mesh with a greater number of nodes. Another way, involves adaptive mesh refinement. In this case, the mesh nodes have non equidistant spacing which allow a non uniform node...

  9. Research on Adaptive Dual-Mode Switch Control Strategy for Vehicle Maglev Flywheel Battery

    Directory of Open Access Journals (Sweden)

    Hui Gao

    2015-01-01

    Full Text Available Because of the jamming signal is real-time changeable and control algorithm cannot timely tracking control flywheel rotor, this paper takes vehicle maglev flywheel battery as the research object. One kind of dual-model control strategy is developed based on the analysis of the vibration response impact of the flywheel battery control system. In view of the complex foundation vibration problems of electric vehicles, the nonlinear dynamic simulation model of vehicle maglev flywheel battery is solved. Through analyzing the nonlinear vibration response characteristics, one kind of dual-mode adaptive hybrid control strategy based on H∞ control and unbalance displacement feed-forward compensation control is presented and a real-time switch controller is designed. The reliable hybrid control is implemented, and the stability in the process of real-time switch is solved. The results of this project can provide important basic theory support for the research of vehicle maglev flywheel battery control system.

  10. Evaluation of control strategies in forming processes

    Directory of Open Access Journals (Sweden)

    Calmano Stefan

    2015-01-01

    Full Text Available Products of forming processes are subject to quality fluctuations due to uncertainty in semi-finished part properties as well as process conditions and environment. An approach to cope with these uncertainties is the implementation of a closed-loop control taking into account the actual product properties measured by sensors or estimated by a mathematical process model. Both methods of uncertainty control trade off with a financial effort. In case of sensor integration the effort is the cost of the sensor including signal processing as well as the design and manufacturing effort for integration. In case of an estimation model the effort is mainly determined by the time and knowledge needed to derive the model, identify the parameters and implement the model into the PLC. The risk of mismatch between model and reality as well as the risk of wrong parameter identification can be assumed as additional uncertainty (model uncertainty. This paper evaluates controlled and additional uncertainty by taking into account process boundary conditions like the degree of fluctuations in semi-finished part properties. The proposed evaluation is demonstrated by the analysis of exemplary processes.

  11. 基于开绕组结构的永磁风力发电机控制策略%Control strategy of permanent magnet wind generator based on open winding configuration

    Institute of Scientific and Technical Information of China (English)

    年珩; 周义杰; 李嘉文

    2013-01-01

    Aimed at the operation demands on the large capacity and high performance of permanent mag net synchronous generator (PMSG) for wind power generation system, the generation system with open winding based PMSG and two cascaded two-level converter is built, in which the vector control, position sensorless control, space vector modulation are investigated. By analyzing the mathematic model of the open winding PMSG, the vector control strategy based on the rotor flux orientation and the sensorless op eration technique based on the back electromotive force estimation was implemented, and then the target vector assignment method and the corresponding space vector modulation strategy for the two generator-side converter were also studied. The analysis results indicate that the proposed open winding PMSG sys tem can not only decrease the generator-side converter capacity, but achieve the three-level modulation effect. The correctness and availability of the proposed system and control strategy are validated by the experimental results.%为了实现永磁风力发电机组大容量、高性能的运行需求,建立一种基于开绕组结构的永磁同步发电机和两个级联两电平变流器组成的风力发电系统.对该系统所采用的矢量控制、无位置传感器运行、空间矢量调制等技术进行了研究.通过建立开绕组永磁同步发电机的数学模型,得出基于转子磁场定向的矢量控制策略,进而结合基于反电势估算法的无位置传感器运行技术,研究了开绕组永磁同步发电机在两个机侧变流器下的目标矢量分配方法及对应的空间矢量调制策略.分析结果表明,所提出的开绕组永磁同步发电系统不仅降低了机侧变流器的容量,还起到了三电平的调制效果.实验结果验证了所提结构及控制策略的正确性和可行性.

  12. Model-Based Power Plant Master Control

    Energy Technology Data Exchange (ETDEWEB)

    Boman, Katarina; Thomas, Jean; Funkquist, Jonas

    2010-08-15

    The main goal of the project has been to evaluate the potential of a coordinated master control for a solid fuel power plant in terms of tracking capability, stability and robustness. The control strategy has been model-based predictive control (MPC) and the plant used in the case study has been the Vattenfall power plant Idbaecken in Nykoeping. A dynamic plant model based on nonlinear physical models was used to imitate the true plant in MATLAB/SIMULINK simulations. The basis for this model was already developed in previous Vattenfall internal projects, along with a simulation model of the existing control implementation with traditional PID controllers. The existing PID control is used as a reference performance, and it has been thoroughly studied and tuned in these previous Vattenfall internal projects. A turbine model was developed with characteristics based on the results of steady-state simulations of the plant using the software EBSILON. Using the derived model as a representative for the actual process, an MPC control strategy was developed using linearization and gain-scheduling. The control signal constraints (rate of change) and constraints on outputs were implemented to comply with plant constraints. After tuning the MPC control parameters, a number of simulation scenarios were performed to compare the MPC strategy with the existing PID control structure. The simulation scenarios also included cases highlighting the robustness properties of the MPC strategy. From the study, the main conclusions are: - The proposed Master MPC controller shows excellent set-point tracking performance even though the plant has strong interactions and non-linearity, and the controls and their rate of change are bounded. - The proposed Master MPC controller is robust, stable in the presence of disturbances and parameter variations. Even though the current study only considered a very small number of the possible disturbances and modelling errors, the considered cases are

  13. Research on transient hysteresis current control strategy of DC-DC converter

    Science.gov (United States)

    Zhang, Ting; Wang, Zu-liang; Zhao, Yu-kai

    2017-01-01

    In order to improve the dynamic performance of DC-DC converter, transient hysteresis current control strategy is proposed which is based on parallel computing and combinational logic. By making a comparison between the real-time inductor current and the threshold inductor current, the switch is controlled more accurately. Under the Matlab/Simulink environment, the process of the Buck-Boost converter was simulated. The simulation results show that the transient hysteresis current control strategy can effectively overcome the disadvantages when load changes or input voltage disturbance occurs, it posses high load regulation and short dynamic response time, and it verifies the feasibility of the proposed strategy.

  14. Novel strategies for control of fermentation processes

    DEFF Research Database (Denmark)

    Mears, Lisa; Stocks, Stuart; Sin, Gürkan;

    Bioprocesses are inherently sensitive to fluctuations in processing conditions and must be tightly regulated to maintain cellular productivity. Industrial fermentations are often difficult to replicate across production sites or between facilities as the small operating differences in the equipment...... of a fermentation. Industrial fermentation processes are typically operated in fed batch mode, which also poses specific challenges for process monitoring and control. This is due to many reasons including non-linear behaviour, and a relatively poor understanding of the system dynamics. It is therefore challenging...

  15. Air Traffic Controllers' Control Strategies in the Terminal Area Under Off-Nominal Conditions

    Science.gov (United States)

    Martin, Lynne; Mercer, Joey; Callantine, Todd; Kupfer, Michael; Cabrall, Christopher

    2012-01-01

    A human-in-the-loop simulation investigated the robustness of a schedule-based terminal-area air traffic management concept, and its supporting controller tools, to off-nominal events - events that led to situations in which runway arrival schedules required adjustments and controllers could no longer use speed control alone to impose the necessary delays. The main research question was exploratory: to assess whether controllers could safely resolve and control the traffic during off-nominal events. A focus was the role of the supervisor - how he managed the schedules, how he assisted the controllers, what strategies he used, and which combinations of tools he used. Observations and questionnaire responses revealed supervisor strategies for resolving events followed a similar pattern: a standard approach specific to each type of event often resolved to a smooth conclusion. However, due to the range of factors influencing the event (e.g., environmental conditions, aircraft density on the schedule, etc.), sometimes the plan required revision and actions had a wide-ranging effect.

  16. PERFUSION SYSTEM CONTROLLER STRATEGIES DURING AN ECMO SUPPORT

    OpenAIRE

    2014-01-01

    In this work modelling and control of Perfusion system is presented. The Perfusion system simultaneously controls the partial pressures during Extra Corporeal Membrane Oxygenation (ECMO) support. The main Problem in ECMO system is exchange of Blood Gases in the Artificial Lung (Oxygenator).It is a highly Nonlinear Process comprising time-varying parameters, and varying time delays, it is currently being controlled manually by trained Perfusionist. The new control strategy implemen...

  17. 基于轴矩限幅控制的机械谐振抑制技术%Mechanical resonance suppression strategy based on shaft torque amplitude limiting control

    Institute of Scientific and Technical Information of China (English)

    杨明; 王璨; 徐殿国

    2015-01-01

    为了探究伺服驱动系统中,由于机械传动装置有限的刚度而引发的机械谐振现象,甚至当振幅较大,超过轴系所能承受的最大转矩范围而引发系统安全问题,在双惯量弹性系统模型基础上,研究速度环控制器的4种不同实现方法的控制性能,即工程设计法、极点配置法、轴矩状态反馈法设计的PI控制器和模型预测控制器。通过4种方法的仿真结果,分析了相应的控制效果,同时验证了模型预测控制为最优的控制策略:在抑制机械谐振的同时,可以在保证系统快速动态性能的基础上,对轴矩实现任意限幅功能,从而加强系统运行的安全性。%In servo-drive systems, the stiffness of transmission mechanism is limited which will lead to mechanical resonance and if the oscillation amplitude is larger than the tolerance that the shaft can with-stand, it will lead to the system safety problems. In order to study these problems, based on the model of two-mass elastic system, the four design schemes of speed controller were analyzed. They are engineering design method, pole placement method and shaft torque state feedback, all of which are all based on PI controller and model predictive controller. Control effects of the four strategies were compared by the sim-ulation results. Model predictive controller was verified as the optimal control strategy which can suppress mechanical resonance successfully. Moreover, based on the fast dynamic performance, the function of shaft torque limit at arbitrary value can be achieved to strengthen the operating safety of the system.

  18. 基于模糊神经分数阶PID的储能电源逆变控制%Control strategy for energy storage system inverter based onfuzzyPIDneural network controller

    Institute of Scientific and Technical Information of China (English)

    倪磊; 樊波; 牛天林; 边岗莹; 赵广胜

    2016-01-01

    针对传统PID控制器存在抗干扰能力差、参数整定困难、时变控制不确定等不足,为进一步提高储能电源逆变输出电压波形质量,增强控制系统的鲁棒性,提出了基于优化模糊PID控制器的控制策略。在介绍分数阶控制器定义及其数学实现的基础上,该方法引入模糊控制规则对控制器的结构参数进行调整,同时融合了神经网络的自学习能力,通过在系统工作时动态调整隶属函数和完善模糊控制规则,实现控制器参数的在线调节和优化。仿真结果表明,优化后的控制器具有更灵活的结构和更强的鲁棒性,具备良好的动态特性和自适应能力,能够满足储能电源逆变控制的要求。%The traditional PID controller has a shortage of an-interference performance, parameters setting and time-varying control. In order to improve the output-voltage performance of the inverter and robustness of battery energy storage system power supply, this paper puts forward a control method based on optimized fuzzy PID controller. Based on expounding the definition and math algorithm of fractional order controller, the method introduces fuzzy control rules to adjust the parameters of the controller, meanwhile, combines with the self-learning ability of the neural network to adjust and optimize the controller parameters online by improving the membership function and fuzzy control rules constantly. The simulation results show that the quality of anti-interference and robust of the optimized control system are enhanced, the controller hasbetter construction and dynamic performance, above all, the optimized control methods are feasible for the inverter of battery energy storage system.

  19. Therapeutic Strategies Based on Polymeric Microparticles

    Directory of Open Access Journals (Sweden)

    C. Vilos

    2012-01-01

    Full Text Available The development of the field of materials science, the ability to perform multidisciplinary scientific work, and the need for novel administration technologies that maximize therapeutic effects and minimize adverse reactions to readily available drugs have led to the development of delivery systems based on microencapsulation, which has taken one step closer to the target of personalized medicine. Drug delivery systems based on polymeric microparticles are generating a strong impact on preclinical and clinical drug development and have reached a broad development in different fields supporting a critical role in the near future of medical practice. This paper presents the foundations of polymeric microparticles based on their formulation, mechanisms of drug release and some of their innovative therapeutic strategies to board multiple diseases.

  20. Capacitor Current Feedback-Based Active Resonance Damping Strategies for Digitally-Controlled Inductive-Capacitive-Inductive-Filtered Grid-Connected Inverters

    DEFF Research Database (Denmark)

    Lorzadeh, Iman; Askarian Abyaneh, Hossein; Savaghebi, Mehdi

    2016-01-01

    Inductive-capacitive-inductive (LCL)-type line filters are widely used in grid-connected voltage source inverters (VSIs), since they can provide substantially improved attenuation of switching harmonics in currents injected into the grid with lower cost, weight and power losses than their L......-type counterparts. However, the inclusion of third order LCL network complicates the current control design regarding the system stability issues because of an inherent resonance peak which appears in the open-loop transfer function of the inverter control system near the control stability boundary. To avoid...... passive (resistive) resonance damping solutions, due to their additional power losses, active damping (AD) techniques are often applied with proper control algorithms in order to damp the LCL filter resonance and stabilize the system. Among these techniques, the capacitor current feedback (CCF) AD has...

  1. Efficient Plant Supervision Strategy Using NN Based Techniques

    Science.gov (United States)

    Garcia, Ramon Ferreiro; Rolle, Jose Luis Calvo; Castelo, Francisco Javier Perez

    Most of non-linear type one and type two control systems suffers from lack of detectability when model based techniques are applied on FDI (fault detection and isolation) tasks. In general, all types of processes suffer from lack of detectability also due to the ambiguity to discriminate the process, sensors and actuators in order to isolate any given fault. This work deals with a strategy to detect and isolate faults which include massive neural networks based functional approximation procedures associated to recursive rule based techniques applied to a parity space approach.

  2. Graded Voltage Control Strategy for Clustering Wind Farms Based on Doubly-fed Induction Generators%集群双馈风电场的分次调压控制

    Institute of Scientific and Technical Information of China (English)

    陈惠粉; 张毅威; 闵勇; 乔颖; 鲁宗相

    2013-01-01

    The characteristics of clustering wind farms are strongly coupled between reactive power and voltage of wind farms and poor communication reliability.Based on these characteristics, this paper proposes a graded voltage control strategy.In the control strategy, doubly-fed induction generators (DFIGs) are main reactive power resources because of their high reliable reactive power generation ability and capacitors/static var compensators (SVCs) are auxiliary reactive power resources.This makes the strategy independent of high speed and high reliability communication between DFIGs and wind farm automatic voltage control (AVC) system.According to the grid operation condition, the PQ curve of DFIG is calculated previously.Based on the pre-setting PQ curve, the reactive power output of DFIG is adjusted automatically to eliminate voltage fluctuation caused by change of active power output.Only when the grid operation condition changes significantly, the PQ curve need to be updated, that means the PQ curve need not be calculated in real time.When the voltage control aim is not achieved or the updating of PQ curve does not finish, capacitors/SVCs are then used to control voltage, which is called the secondary voltage control.Simulations on a real clustering wind farms in northern China is carried out.The results show that the probability of wind generators' cascading disconnection from power grid is reduced effectively with the proposed graded voltage control strategy.Communication failures between DFIGs and wind farm AVC system have no influences on control effect.%基于集群风电场间无功电压耦合较强、通信条件较差的特点,提出以双馈风电机组为主、电容器/静止无功补偿器(SVC)为辅,不过分依赖风电机组与风电场自动电压控制系统间通信的集群双馈风电场分次调压控制策略.事先根据电网运行状况计算得到不需实时更新的双馈风电机组的PQ曲线,同步补偿无功功率以应对有功出

  3. Suppression as a stereotype control strategy.

    Science.gov (United States)

    Monteith, M J; Sherman, J W; Devine, P G

    1998-01-01

    Recent research reveals that efforts to suppress stereotypic thoughts can backfire and produce a rebound effect, such that stereotypic thinking increases to a level that is even greater than if no attempt at stereotype control was initially exercised (e.g., Macrae, Bodenhausen, Milne, & Jetten, 1994). The primary goal of this article is to present an in-depth theoretical analysis of stereotype suppression that identifies numerous potential moderators of the effect of stereotype suppression on the likelihood of subsequent rebound. Our analysis of stereotype suppression focuses on two broad issues: the influence of level of prejudice and the influence of processing goals on the activation versus application of stereotypes. Although stereotype rebound occurs under some circumstances, we suggest that a complete understanding of this phenomenon requires consideration of the full array of possible moderating influences.

  4. Base-of-the-pyramid global strategy

    Directory of Open Access Journals (Sweden)

    Boşcor, D.

    2010-12-01

    Full Text Available Global strategies for MNCs should focus on customers in emerging and developing markets instead of customers in developed economies. The “base-of-the-pyramid segment” comprises 4 billion people in the world. In order to be successful, companies will be required to form unconventional partnerships- with entities ranging from local governments to non-profit organizations - to gain the community’s trust and understand the environmental, infrastructure and political issues that may affect business. Being able to provide affordable, high-quality products and services in this market segment often means new approaches to marketing- new packaging and pricing structures, and using unfamiliar distribution structures.

  5. 基于流体力学的工业煤粉锅炉配风控制策略%Application of Control Strategy Based on the Fluid Mechanics Principle to the Air Distribution Control of Industry Pulverized Coal Fired Boiler

    Institute of Scientific and Technical Information of China (English)

    麻林

    2014-01-01

    the control strategy is the core of control system, the control strategy can directly influence the in⁃dustrial equipment in operation safety, stable and efficient. The control system is mostly through the feed⁃back signal as a control strategy decision, and the lag of feedback signal, often causes the device to run shocks to adjust time is too long, and even lead to equipment downtime or safety accident. Based on small and medium-sized industrial pulverized coal boiler air distribution control as an example, the application of the air distribution control strategy based on fluid mechanics principle as the foundation, and combining with the feedback signal, effectively reduce boiler shocks to adjust time, make the boiler as soon as possible into the steady combustion state, effectively improve the boiler's safety and stability, further improve the automa⁃tion of industrial coal the boiler level control.%文章以中小型工业煤粉锅炉的配风控制为例,应用了以流体力学原理为基础的配风控制策略,同时结合反馈信号,有效减少锅炉震荡调整时间,使锅炉尽快进入稳定燃烧状态,有效地提高了锅炉的安全性和稳定性,进一步提高工业煤粉锅炉的自动化控制水平。

  6. PERFUSION SYSTEM CONTROLLER STRATEGIES DURING AN ECMO SUPPORT

    Directory of Open Access Journals (Sweden)

    M.Dhinakaran

    2014-12-01

    Full Text Available In this work modelling and control of Perfusion system is presented. The Perfusion system simultaneously controls the partial pressures during Extra Corporeal Membrane Oxygenation (ECMO support. The main Problem in ECMO system is exchange of Blood Gases in the Artificial Lung (Oxygenator.It is a highly Nonlinear Process comprising time-varying parameters, and varying time delays, it is currently being controlled manually by trained Perfusionist. The new control strategy implemented here has a feedback linearization routine with time-delay compensation for the Partial pressuresof Oxygen and Carbon dioxide. The controllers were tuned robustly and tested in simulations with a detailed artificial Lung (Oxygenator model in Cardiopulmonary bypass conditions. This Automatic control strategy is proposed to improve the patient’s safety by fast control reference tracking and good disturbance rejection under varying conditions.

  7. Methods in Logic Based Control

    DEFF Research Database (Denmark)

    Christensen, Georg Kronborg

    1999-01-01

    Desing and theory of Logic Based Control systems.Boolean Algebra, Karnaugh Map, Quine McClusky's algorithm. Sequential control design. Logic Based Control Method, Cascade Control Method. Implementation techniques: relay, pneumatic, TTL/CMOS,PAL and PLC- and Soft_PLC implementation. PLC-design met......Desing and theory of Logic Based Control systems.Boolean Algebra, Karnaugh Map, Quine McClusky's algorithm. Sequential control design. Logic Based Control Method, Cascade Control Method. Implementation techniques: relay, pneumatic, TTL/CMOS,PAL and PLC- and Soft_PLC implementation. PLC...

  8. Study of the Fuzzy PID Control Strategy of Brushless DC Motor Based on SIMULINK%基于SIMULINK的无刷直流电机模糊PID控制策略研究

    Institute of Scientific and Technical Information of China (English)

    邓志良; 易兴邦

    2011-01-01

    Based on analyzing the mathematical model of square-wave brushless DC motor,aiming at the typical operating mode of the 2-phase turn-on 3-phase 6-state with wye-connected,the paper proposes a fuzzy PID control strategy.A fuzzy PID control strategy simulation model is established on Matlab/Simulink platform and then fuzzy PID of brushless DC motor model is also simulated by changing parameters.The control results are compared with that of fuzzy PID and conventional PID control.The results of simulation indicate that the system has the advantages of strong robustness,fast response time and high steady-state accuracy.%在分析方波型永磁无刷直流电动机(BLDCM)数学模型的基础上,针对典型的两相导通星型三相六状态工作方式的无刷直流电动机,提出了一种模糊PID控制方法,在Matlab/Simulink平台上建立了无刷直流电机模糊PID控制策略的仿真模型,改变参数后,对其也进行了仿真,并且将模糊PID控制和传统PID控制的控制效果进行了比较。仿真结果表明:建立的该系统具有鲁棒性强、响应速度快、无超调,且稳态精度高等优点。

  9. Porcine Rotaviruses: Epidemiology, Immune Responses and Control Strategies

    Science.gov (United States)

    Vlasova, Anastasia N.; Amimo, Joshua O.; Saif, Linda J.

    2017-01-01

    Rotaviruses (RVs) are a major cause of acute viral gastroenteritis in young animals and children worldwide. Immunocompetent adults of different species become resistant to clinical disease due to post-infection immunity, immune system maturation and gut physiological changes. Of the 9 RV genogroups (A–I), RV A, B, and C (RVA, RVB, and RVC, respectively) are associated with diarrhea in piglets. Although discovered decades ago, porcine genogroup E RVs (RVE) are uncommon and their pathogenesis is not studied well. The presence of porcine RV H (RVH), a newly defined distinct genogroup, was recently confirmed in diarrheic pigs in Japan, Brazil, and the US. The complex epidemiology, pathogenicity and high genetic diversity of porcine RVAs are widely recognized and well-studied. More recent data show a significant genetic diversity based on the VP7 gene analysis of RVB and C strains in pigs. In this review, we will summarize previous and recent research to provide insights on historic and current prevalence and genetic diversity of porcine RVs in different geographic regions and production systems. We will also provide a brief overview of immune responses to porcine RVs, available control strategies and zoonotic potential of different RV genotypes. An improved understanding of the above parameters may lead to the development of more optimal strategies to manage RV diarrheal disease in swine and humans. PMID:28335454

  10. Migration control: a distance compensation strategy in ants.

    Science.gov (United States)

    O'Shea-Wheller, Thomas A; Sendova-Franks, Ana B; Franks, Nigel R

    2016-08-01

    Migratory behaviour forms an intrinsic part of the life histories of many organisms but is often a high-risk process. Consequently, varied strategies have evolved to negate such risks, but empirical data relating to their functioning are limited. In this study, we use the model system of the house-hunting ant Temnothorax albipennis to demonstrate a key strategy that can shorten migration exposure times in a group of social insects. Colonies of these ants frequently migrate to new nest sites, and due to the nature of their habitat, the distances over which they do so are variable, leading to fluctuating potential costs dependent on migration parameters. We show that colonies of this species facultatively alter the dynamics of a migration and so compensate for the distance over which a given migration occurs. Specifically, they achieve this by modulating the rate of 'tandem running', in which workers teach each other the route to a new nest site. Using this method, colonies are able to engage a larger number of individuals in the migration process when the distance to be traversed is greater, and furthermore, the system appears to be based on perceived encounter rate at the individual level. This form of decentralised control highlights the adaptive nature of a behaviour of ecological importance, and indicates that the key to its robustness lies in the use of simple rules. Additionally, our results suggest that such coordinated group reactions are central to achieving the high levels of ecological success seen in many eusocial organisms.

  11. 基于AHP的建筑施工安全管理风险控制策略%Safety Management Risk Control Strategy Based on AHP for Building Construction lndustry

    Institute of Scientific and Technical Information of China (English)

    李松晨; 杨高升

    2014-01-01

    Along with the vigorous development of the building construction industry in our country, the current status of safety management in this area is not perfect. The hidden dangers and potential risks in building construction are presented, and the control strategy based on analytic hierachy process( AHP) is proposed. With this strategy, the qualitative issues are quantified, in accordance with the determined evaluation objects, the hierarchy is established, and the judgment matrix is structured, thus the risk assessment is elaborated specifically. By combining the quantitative evaluation and qualitative evaluation, the determination method of the evaluation value is given. This risk control strategy greatly enhances the security of building construction.%随着我国建筑工程行业的蓬勃发展,建筑施工的安全管理现状存在安全问题。介绍了建筑施工行业存在的安全隐患和潜在风险,提出了基于层次分析法( AHP)的建筑施工风险控制策略。将定性问题定量化,按照确定评价目标、建立递阶层次、构造判断矩阵等步骤对风险评价进行了具体的阐述;将定量评价与定性评价相结合,给出了评价值判定方法。结合建筑施工安全管理办法,该风险控制策略大大提升了建筑施工过程中的安全性。

  12. Fusion Control Strategy Based on I-Fuzzy-Smith Algorithm for Complex Process with Large Lag%大时滞复杂过程中基于I-Fuzzy-Smith算法的融合控制策略

    Institute of Scientific and Technical Information of China (English)

    倪元敏

    2013-01-01

    Aimed at the puzzle to actualize the high quality control in complex process with large lag,the paper presented a sort of fusion control strategy based on the integration of integral, fuzzy and Smith estimator control algorithm.In the paper,it studied the cybernetics characteristic of complex process with large lag and its control puzzle,integrated itself superiority of integral, fuzzy and Smith estimator control,gave a sort of I-Fuzzy-Smith fusion control algorithm.It took a complex process of large inertia with large lag as an example,under the environment of Matlab, and made the detailed simulation experiment in contrast such as robustness etc.The system re-sponse curve demonstrated that the I-Fuzzy-Smith based control algorithm excels than others in dynamical and steady control quality and robustness.The research result shows that the pro-posed control algorithm is high in control precision,better in dynamical and steady control quality, and very strong robustness.%针对大时滞复杂过程难以实施高品质控制,提出了一种基于I-Fuzzy-Smith算法的融合控制策略。研究了大时滞复杂过程的控制论特性与控制难点,以及集成模糊、Smith预估和积分控制各自的优势,给出了将其融合的I-Fuzzy-Smith控制算法。以大惯性大时滞过程为例,基于Matlab仿真对融合控制进行了比较研究,系统响应验证了I-Fuzzy-Smith控制算法的动、静态控制品质和鲁棒性优于另外两种算法。研究结果表明:提出的融合策略控制精度高,系统动、静态控制品质好,表现出很强的鲁棒性。

  13. Forward Link Power Control Strategy and its Optimum Issue in CDMA Cellular Networks

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper, we propose a theoretical method in order to estimate the forward link outage probability and user capacity of a cellular system which are based on IS-95 CDMA standard, especialy impact of power control strategy and voice activity monitoring in the system under long-term fading effects, in which the light and heavy fadings are considered. According to the numerical results obtained in this paper, the power control strategy leads to approximately the threefold user capacity in contrast to the situation without power control strategy. The reults are compared with Interference-to-Signal Ratio (ISR) driven power control scheme[6][9] which can be used only for simulation of the system. The power control strategy not only improves the desired signal to the interference ratio in the reference user's receiver, but also offers uniform service to the user wherever it is located in the cell.

  14. 基于滑模变结构PI控制的光伏系统MPPT研究%Novel hybrid control of MPPT method based on sliding mode variable structure and PI strategy

    Institute of Scientific and Technical Information of China (English)

    靳艳华; 惠晶; 谢伟

    2014-01-01

    Based on the analysis results of the photovoltaic power generation model and its output character, the proposed control er of sliding mode variable structure based on improved Zeta converter was proposed to realize Maximum Power Point Tracking (MPPT) of photovoltaic system. In order to obtain the optimized maximum power point control, the novel hybrid control of the Sliding Mode Variable Structure with variable switch parameter and PI strategy were presented. By comparing traditional P&O method with the proposed method by simulation and experiment, the good characters of the proposed method were verified.%在分析光伏电池的数学模型和输出特性基础上,给出基于改进的Zeta电路的滑模变结构控制策略。为实现光伏系统最大功率点跟踪(MPPT)的优化控制,提出可变阀值切换的滑模变结构+PI复合控制策略,实现了最大功率跟踪的优化控制。通过仿真与实验结果分析,并将给出的控制策略与广泛应用的扰动观测MPPT策略进行比较,验证了本控制策略具有良好的特性。

  15. Study of fuel control strategy based on an fuel behavior model for starting conditions; Nenryo kyodo model ni motozuita shidoji no nenryo hosei hosho ni tsuite no kosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Y.; Uchida, M.; Iwano, H.; Oba, H. [Nissan Motor Co. Ltd., Tokyo (Japan)

    1997-10-01

    We have applied a fuel behavior model to a fuel injection system which we call SOFIS (Sophisticated and Optimized Fuel Injection System) so that we get air/fuel ratio control accuracy and good driveability. However the fuel behavior under starting conditions is still not clear. To meet low emission rules and to get better driveability under starting conditions, better air/fuel ratio control is necessary. Now we have understood the ignition timing, injection timing, and injection pulse width required in such conditions. In former days, we analyzed the state of the air/fuel mixture under cold conditions and made a new fuel behavior model which considered fuel loss such as hydrocarbons and dissolution into oil and so on. Al this time, we have applied this idea to starting. We confirm this new model offers improved air/fuel ratio control. 6 refs., 9 figs., 3 tabs.

  16. Distributed-dispersed renewable energy systems and novel control strategies

    Science.gov (United States)

    Aljankawey, Abdualah S.

    Renewable green-energy systems are re-emerging as viable economic alternative sources of environmentally safe power generation in place of conventional fossil fuels. In terms of power quality and safety, this research investigates a number of renewable green-energy (wind, photovoltaic and fuel cells) interface schemes and control strategies that ensure maximum energy utilization, voltage and frequency stabilization and minimum impact on the host electric grid systems. The research key objectives are to study efficient and robust renewable energy converter schemes with associated control strategies and validate their operations for both stand-alone and electric utility grid interfacing. The research work investigates both stand-alone and grid connected renewable green-energy utilization schemes with a number of power electronic converter topologies and robust control schemes for both dispersed and hybrid renewable energy systems. Different sample study systems and control strategies are digitally simulated and fully validated using the MATLAB-Simulink-SimPower environment.

  17. 基于电压下垂法的直流微电网混合储能系统控制策略%Control Strategy of Hybrid Energy Storage Systems in DC Microgrid Based on Voltage Droop Method

    Institute of Scientific and Technical Information of China (English)

    文波; 秦文萍; 韩肖清; 王鹏; 刘家赢

    2015-01-01

    Aiming at stabilizing the DC bus voltage and optimizing the working process of the batteries, this paper presents a control strategy of hybrid energy storage systems in DC microgrid based on voltage droop method. The control strategy makes use of the ultracapacitor compensating the high-frequency components of bus power according to the DC bus voltage, indirectly compensates low-frequency components of bus power through the energy supplement of the batteries on the ultracapacitor, and takes advantage of the unable mutation characteristics of ultracapacitor voltage to achieve the smooth control of battery current. The control system can automatically switch work mode according to the conditions of DC bus voltage, ultracapacitor voltage and the state of charge (SOC) of battery. The experiments show that the control strategy can automatically adjust the output of batteries and ultracapacitor, maintain light fluctuation of DC bus voltage around rating, effectively reduce the frequency of battery charging and discharging and extend its using life.%以稳定直流母线电压和优化蓄电池工作过程为目的,提出了一种基于电压下垂法的直流微电网混合储能控制策略。该控制策略根据直流母线电压信息,利用超级电容快速补偿母线功率缺额的高频部分;通过蓄电池对超级电容进行能量补充,间接补偿母线功率缺额的低频部分;利用超级电容电压不能突变的特点,实现对蓄电池电流的平滑控制。控制系统以直流母线电压、超级电容电压及蓄电池荷电状态为判断条件,自动切换工作模式。实验表明,该控制策略可自动调节蓄电池和超级电容出力,维持直流母线电压在额定值附近小范围波动,有效地减小了蓄电池充放电次数,延长其使用寿命。

  18. 基于临界区划分的实时事务并发控制机制%COR-based Concurrency Control Strategies in the Real-time Transaction Model Supporting Functional Alternatives

    Institute of Scientific and Technical Information of China (English)

    夏家莉; 王文乐; 朱文婷; 曹重华

    2013-01-01

    针对支持功能替代的实时事务模型,根据替代做处理的数据对象将替代划分为若干个临界区,提出了临界区动态相容检测方法,提出了基于临界区动态相容的并发控制策略COR-CCS:分区封锁策略、支持预释放的封锁策略、按序提交策略和级联回滚策略,并给出了相应的并发控制实现算法.当实时系统中存在资源冲突时,若高优先级替代未完成的临界区与低优先级替代动态相容,可令二者并发执行.实验仿真结果证明,COR-CCS策略有利减少低优先级替代等待时间、提高系统成功率和CPU有效利用率.%In the real-time system model based on functional alternatives, we divided the alternatives into Critical Operation Regions (short for CORs) according to the data that they handled, and proposed the method to examine the dynamic compatibility between two CORs. Also, we present the strategies, named COR-CCS, that can improve the concurrence of the alternatives, such as: the strategy of locking each by COR, the strategy of pre-releasing lock, the strategy of orderly submitting and the strategy of cascaded roll-backing. After that we gave the algorithm of COR-based concurrency control. When scheduling the real-time system with data confliction, the alternatives can concurrently executed if the CORS in the alternative with higher priority is dynamic compatibility with the lower priority alternative. The experimental results showed that the COR-CCS is effect on reducing the waiting time of the lower priority alternatives, increasing the successful execution ratio of the transactions, and improving the CPU usage.

  19. Structure and Control Strategies of Fuel Cell Vehicle

    Institute of Scientific and Technical Information of China (English)

    宋建国; 张承宁; 孙逢春; 钟秋海

    2004-01-01

    The structure and kinds of the fuel cell vehicle (FCV) and the mathematical model of the fuel cell processor are discussed in detail. FCV includes many parts: the fuel cell thermal and water management, fuel supply, air supply and distribution, AC motor drive, main and auxiliary power management, and overall vehicle control system. So it requires different kinds of control strategies, such as the PID method, zero-pole method, optimal control method, fuzzy control and neural network control. Along with the progress of control method, the fuel cell vehicle's stability and reliability is up-and-up. Experiment results show FCV has high energy efficiency.

  20. Procoagulant control strategies for the human blood clotting process.

    Science.gov (United States)

    Laurino, Marco; Menara, Tommaso; Stella, Alessandro; Betta, Monica; Landi, Alberto

    2015-08-01

    This paper describes the comparison between two drug control strategies to hemophilia A. To emulate blood clotting and the pathological condition of hemophilia, a mathematical model composed by 14 ordinary differential equations is considered. We adopt a variable structure non-linear PID approach and a Model Predictive Control in order to control the dosage of procoagulant factor used in the treatment of hemophiliac patient. The two control actions are sampled for a practical application. Finally, we discuss and compare the results of the two control approaches, introducing a suited control index (eINR).

  1. 基于优先顺序法的风电场限出力有功控制策略%Priority List-Based Output-Restricted Active Power Control Strategy for Wind Farms

    Institute of Scientific and Technical Information of China (English)

    林俐; 谢永俊; 朱晨宸; 汪宁渤

    2013-01-01

    With the rapid increase of grid-integrated capacity of wind farms, wind farms should possess the adjusting ability of active power that can control active power output of wind farm according to the command from control center of power grid. Combining with actual requirement for active power control system of clustered wind farms in Jiuquan wind power base in Gansu province, China, taking the utilization of wind energy farthest and the prevention of frequent start/stop of wind power generators as the objectives and based on classical priority list method, an output-restricted active power control strategy for wind farms composed of variable speed constant frequency (VSCF) wind power generators is proposed. To meet the demand on output-restricted control for wind farms, an active power control frame in the level of wind farm and corresponding output-restricted control process are designed. Overall considering the prediction information, operating conditions and control characteristics of wind power generation units within wind farms, an output-restricted active power control sequence for wind farms, in which the indices of control performances of wind power generation units are taken as the index for rank ordering, is established, and then, based on the control sequence the method to allocate output-restricted active power is given. The correctness and effectiveness of the proposed control strategy are verified by the calculation of a wind farm composed of 33 doubly fed induction generators.%  随着风电并网容量的增加,风电场应具备有功功率调节能力,能根据电网调度部门指令控制其有功功率输出。结合甘肃酒泉风电基地集群风电有功控制系统的实际需要,以实现最大风能利用、避免风电场频繁起停为目标,基于经典优先顺序法提出了一种应用于变速恒频风电场的限出力有功控制策略。针对风电场限出力控制需要,设计了风电场层有功

  2. Relationship of Metacognition Learning Strategy and Locus of Control with Academic Achievement of Students

    Directory of Open Access Journals (Sweden)

    Mohammadi Y

    2015-12-01

    Full Text Available Aims: Academic achievement is one of the main assessment factors in the higher education system. Metacognitive learning strategy and locus of control are the main factors affecting the students’ academic achievement. The aim of this study was to investigate the correlation between metacognitive learning strategy and locus of control and the students’ academic achievement.  Instrument & Methods: In the descriptive-analytic study, 335 students of Birjand University of Medical sciences were selected based on Krejcie-Morgan Table and via Stratified Random Sampling Method in 2014-15 academic year. The study tools were Self-regulating Learning Strategies Questionnaire, Locus of Control Survey, and students’ GPA as academic achievement component. Data was analyzed in SPSS 14 software using Pearson Correlation, Independent T, and One-way ANOVA tests. Findings: There was a positive and significant correlation between the dimensions of meta-cognitive learning strategy and internal locus of control and academic achievement. Nevertheless, there was a negative and significant correlation between meta-cognitive learning strategies and external locus of control (p0.05. There was a significant correlation between the students’ academic achievements based on gender. However, based on age and faculty, it was not significant.    Conclusion: Two important factors affecting learning enhancement and academic achievement in the students are meta-cognitive learning strategy and locus of control.

  3. 基于负序电压补偿的VSC-HVDC系统的不平衡控制%Unbalanced control strategy based on negative voltage compensation for VSC-HVDC system

    Institute of Scientific and Technical Information of China (English)

    杨硕; 张卫星; 李德泉

    2012-01-01

    交流系统故障时VSC-HVDC系统的控制策略直接关系到系统的运行和安全性能,具有明显的工程应用价值.建立了交流系统不平衡故障时d-q同步旋转坐标系下系统换流器的正负序数学模型,设计了不平衡条件下的同步相位和正负序分量的实时检测系统.采用非线性系统反馈线性化理论,设计了系统的状态反馈线性化电流解耦控制器.在此基础上设计了负序电压补偿的不平衡控制系统,在有效抑制负序电流的同时,简化了控制系统结构.基于PSIM的数字仿真,验证了所设计的控制器具有良好的控制性能.%The control strategy for unbalanced VSC-HVDC system is directly related to its function and security, so it has a great importance for the engineering. The paper builds a positive and negative mathematical model of VSC in d-q synchronous reference frame, and designs a detecting system of synchronous phase and positive and negative component under unbalanced condition. By using nonlinear transformation and nonlinear system feedback linearization theory, the state-feedback linearization decoupling controller for VSC-HVDC system is established. Finally, the paper designs an unbalanced control strategy based on negative voltage compensation for VSC-HVDC. Besides restraining the negative current, it also simplifies the structure of the control system. The digital simulation based on PSIM proves the designed controller has good control performance.

  4. 基于LVPWM的风电变流器控制技术研究%Control Strategy of the Converter of Wind Generator Based on LVPWM

    Institute of Scientific and Technical Information of China (English)

    魏毅立; 张新; 魏士焕; 吴振奎

    2011-01-01

    变流器是双馈发电机系统的关键部分,它决定着控制系统及发电机输出电能的质量.针对以前的交流器广泛采用空间矢量脉宽调制(SVPWM)控制技术的不足,提出了逻辑电压空间矢量脉宽调制(LVPWM)控制技术,并介绍了其原理.最后搭建了Matlab/Simulink仿真试验平台和基于TMS320F2812 DSP的47kW变流器实验平台,实验结果表明,LVPWM控制技术正确且实用,并具有良好的应用前景.%Converter is the key part of doubly-fed induction generator system, which determines the control system and generator output power performance.The previous converters widely use space vector pulse width modulation(SVPWM)control technology, the article proposes logic voltage space vector pulse width modulation (LVPWM) control technology and describes its principles. In Matlab/Simulink simulation platform, a simulation model is validated. At the same time,TMS320F2812 DSP of 47 kW converter experimental platform is established. The experimental results show that LVPWM control technology is correct and practical, and has good prospects.

  5. Zinc finger artificial transcription factor-based nearest inactive analogue/nearest active analogue strategy used for the identification of plant genes controlling homologous recombination

    NARCIS (Netherlands)

    Jia, Qi; van Verk, Marcel C.; Pinas, Johan E.; Lindhout, Beatrice I.; Hooykaas, Paul J.J.; Van der Zaal, Bert J.

    2013-01-01

    In previous work, we selected a particular transcription factor, designated VP16-HRU, from a pool of zinc finger artificial transcription factors (ZF-ATFs) used for genome interrogation. When expressed in Arabidopsis thaliana under control of the ribosomal protein S5A promoter, the RPS5A::VP16-HRU c

  6. Improved Control Strategy for DFIG Wind Turbines for Low Voltage Ride Through

    Directory of Open Access Journals (Sweden)

    Chanxia Zhu

    2013-02-01

    Full Text Available This paper presents an improved control strategy for both the rotor side converter (RSC and grid side converter (GSC of a doubly fed induction generator (DFIG-based wind turbine (WT system to enhance the low voltage ride through (LVRT capability. Within the proposed control strategy, the RSC control introduces transient feed-forward compensation terms to mitigate the high frequency harmonic components and reduce the surge in the rotor currents. The proposed GSC control scheme also introduces a compensation term reflecting the instantaneous variation of the output power of the rotor side converter with consideration of the instantaneous power of grid filter impendence to keep the dc-link voltage nearly constant during the grid faults. To provide precise control, non-ideal proportional resonant (PR controllers for both the RSC and GSC current regulation are employed to further improve dynamic performance. Simulations performed in Matlab/Simulink verify the effectiveness of the proposed control strategy.

  7. Review of Active and Reactive Power Sharing Strategies in Hierarchical Controlled Microgrids

    DEFF Research Database (Denmark)

    Han, Yang; Li, Hong; Shen, Pan;

    2017-01-01

    Microgrids consist of multiple parallel-connected distributed generation (DG) units with coordinated control strategies, which are able to operate in both grid-connected and islanded mode. Microgrids are attracting more and more attention since they can alleviate the stress of main transmission...... to the influence of impedance mismatch of the DG feeders and the different ratings of the DG units are inevitable when the conventional droop control scheme is adopted. Therefore, the adaptive/improved droop control, network-based control methods and cost-based droop schemes are compared and summarized...... strategies are utilized as supplements of the conventional droop controls and virtual impedance methods. The improved hierarchical control approaches such as the algorithms based on graph theory, multi-agent system, the gain scheduling method and predictive control have been proposed to achieve proper...

  8. A community empowerment strategy embedded in a routine dengue vector control programme: a cluster randomised controlled trial.

    Science.gov (United States)

    Castro, Marta; Sánchez, Lizet; Pérez, Dennis; Carbonell, Nestor; Lefèvre, Pierre; Vanlerberghe, Veerle; Van der Stuyft, Patrick

    2012-05-01

    The non-sustainability of vertically organised dengue vector control programmes led to pleas for changing the emphasis towards community-based strategies. We conducted a cluster randomised controlled trial with 16 intervention and 16 control clusters to test the effectiveness of a community empowerment strategy intertwined with the routine dengue vector control programme in La Lisa, Havana City, Cuba. The intervention included four components on top of routine control: organisation and management; entomological risk surveillance; capacity building; and community work for vector control. In the control clusters, routine activities continued without interference. The community participation score increased from 1.4 to 3.4. Good knowledge of breeding sites increased by 52.8% and 27.5% in the intervention and control clusters, respectively. There were no changes in adequate Aedes aegypti control practices at household level in the control clusters, but in the intervention clusters adequacy increased by 36.2%. At baseline, the Breteau indices (BI) were approximately 0.1 and were comparable; they fluctuated over time but became different with the launch of the community-based dengue control activities in the intervention clusters. Over the intervention period, the BI remained 53% (95% CI 22-92%) lower in these clusters than in the control clusters. The empowerment strategy increased community involvement and added effectiveness to routine A. aegypti control.

  9. Modelling and Control Design of Unified Power Flow Controller for Various Control Strategies

    Directory of Open Access Journals (Sweden)

    T. Nireekshana

    2010-11-01

    Full Text Available Unified Power Flow Controller (UPFC is used to control the power flow in the transmission systems by controlling the impedance, voltage magnitude and phase angle. This controller offers advantages in terms of static and dynamic operation of the power system. It also brings in new challenges in power electronics and power system design. The basic structure of the UPFC consists of two voltage source inverter (VSI; where one converter is connected in parallel to the transmission line while the other is in series with the transmission line. The aim of the paper is to develop a control strategy for UPFC, modeling UPFC using MATLAB/SIMULINK and to analyze the control strategy to use the series voltage injection and shunt current injection for UPFC control. To simplify the design procedure we carry out the design for the series and shunt branches separately.In each case, a simple equivalent circuit represents the external system. The design has to be validated when the various subsystems are integrated.

  10. New software rejuvenation strategy based on measurement and time

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Operational software systems often experience an "aging" phenomenon, characterized by progressive performance degradation and a sudden hang/crash failure. Software rejuvenation is a proactive fault-tolerance strategy aimed to prevent unexpected outages due to aging. A new rejuvenation strategy based on measurement and time, and constructs a SRN model to evaluate this strategy. Numerical results show that this strategy outweighs either the purely measurementbased or the purely time-based strategy and can effectively improve system performance.

  11. An Ethernet LAN based distributed generation system load shedding strategy

    DEFF Research Database (Denmark)

    Wei, Mu; Chen, Zhe

    2011-01-01

    This paper firstly analyzes and compares various communication technologies, and proposes a communication system for a distributed generation system (DGS) with wind turbines. Then the paper presents a novel simulation method of considering the interactions between the communication system and power...... system, by using two software platforms: OPNET and EMTDC/PSCAD. A control method based on the communication technique has been designed to stabilize the DG system during power system disturbances. A case study is presented to demonstrate the effectiveness of the proposed communication system, simulation...... method and control strategy....

  12. Dynamic Protective Control Strategy for Distributed Generation System with Fixed-speed Wind Turbines

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    The characteristics of induction generator based fixed-speed wind turbines (FSWT) are investigated. The impacts of different execution time in protective operations are studied under different fauit duration and various wind velocity situations, e.g. , FSWT stabilities of load shedding in distribution systems. Based on this research, a dynamic protective control strategy for a distributed generation system (DGS) with FSWT is proposed. Finally, simulation results demonstrate the effectiveness of the strategy.

  13. Invasive mechanism and control strategy of Ageratina adenophora (Sprengel)

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In order to ascertain the invasive mechanism and control strategy of the invasive Crofton weed, Ageratina adenophora, its ecological adaptability and population differentiation,the formation of single dominant population, displacement of native plants and sustainable management strategies were investigated. The present results helped to clarify and explain such issues as the adaptability post invasion,interaction and competition between inter-and intra-species and community resistance, thereby providing important references to researches on other invasive alien species.

  14. Control strategy and hardware implementation for DC–DC boost power circuit based on proportional–integral compensator for high voltage application

    Directory of Open Access Journals (Sweden)

    Sanjeevikumar Padmanaban

    2015-06-01

    Full Text Available For high-voltage (HV applications, the designers mostly prefer the classical DC–DC boost converter. However, it lacks due to the limitation of the output voltage by the gain transfer ratio, decreased efficiency and its requirement of two sensors for feedback signals, which creates complex control scheme with increased overall cost. Furthermore, the output voltage and efficiency are reduced due to the self-parasitic behavior of power circuit components. To overcome these drawbacks, this manuscript provides, the theoretical development and hardware implementation of DC–DC step-up (boost power converter circuit for obtaining extra output-voltage high-performance. The proposed circuit substantially improves the high output-voltage by voltage-lift technology with a closed loop proportional–integral controller. This complete numerical model of the converter circuit including closed loop P-I controller is developed in simulation (Matlab/Simulink software and the hardware prototype model is implemented with digital signal processor (DSP TMS320F2812. A detailed performance analysis was carried out under both line and load regulation conditions. Numerical simulation and its verification results provided in this paper, prove the good agreement of the circuit with theoretical background.

  15. 基于混合储能的光伏微网孤网运行的综合控制策略%Comprehensive control strategy of hybrid energy storage-based photovoltaic island microgrid

    Institute of Scientific and Technical Information of China (English)

    田慧雯; 李咸善; 陈铁; 谭思

    2014-01-01

    The output power of the photovoltaic island microgrid is intermittent and random. To ensure the reliability and stability of power supply, the idea that combines the high energy density battery with supercapacitor which has high power density to form hybrid energy storage system applied to photovoltaic (PV) microgrid becomes a research hotspot.On the basis of existing research, this paper proposes a multi-hysteresis control strategy based on energy management.The energy storage system working state can be optimized and the working life of the battery can be greatly improved by this control strategy. Using MATLAB/Simulink software, a simulation module for PV Island microgrid based on hybrid energy storage is constructed, and the control strategy of PV microgrid is verified and analyzed. Simulation results show that the proposed hybrid energy storage system can balance the instantaneous power rapidly, optimize the microgrid operation, and ensure the reliability of power supply.%孤网运行的光伏微网输出功率具有间歇性和随机性。为了保证系统供电的可靠性及稳定性,将能量密度大的蓄电池和功率密度高的超级电容器构成混合储能系统应用于光伏微网的思路成为研究热点。在现有蓄电池电流多滞环控制策略的基础上进行改进,提出基于功率的储能单元控制策略。该方法优化了储能系统的工作状态,有利于提高蓄电池的工作寿命。通过 Matlab/Simulink 仿真软件搭建了基于混合储能的光伏微网孤网运行仿真模型,并对该光伏微网的控制策略进行验证和分析。结果表明,混合储能系统能迅速平衡系统的瞬时功率,优化系统运行状态,保证供电的可靠性。

  16. A Control Strategy for Modular Multilevel Converter Based HVDC of Unbalanced AC Systems%不对称交流电网下MMC-HVDC输电系统的控制策略

    Institute of Scientific and Technical Information of China (English)

    孔明; 汤广福; 贺之渊; 杨杰

    2013-01-01

    The power fluctuation under asymmetric AC voltages caused the sub-module energy unbalance for modular multilevel converters, which thereby affected the dynamic characteristics of the MMC-HVDC system. By analyzing the arm instantaneous power of MMC, the control targets of the sub-module capacitor voltage and the circulating current were determined. On this basis, a control strategy composing of the sub-module capacitor voltage predicted based the nearest level modulation and circulating current predicted based direct circulating current control was presented. Whether the AC system is symmetrical or not, under the proposed control strategy, the voltages of sub-module capacitor each arm were kept balanced relatively, and the fundamental frequency and the second harmonic of the circulating current were suppressed. A MMC-HVDC simulation model of two ends was established based on PSCAD/EMTDC. The simulations under the asymmetric AC grid for the active power and the DC voltage control station were conducted respectively. Simulation results show that the proposed control strategy could keep the average value of the sub-module capacitor voltage remain constant during the AC system asymmetric fault, and avoid the DC voltage fluctuation caused by the zero sequence instantaneous power, which thereby improves the fault ride-through capability of the system.%不对称交流电网下的功率波动将引起模块化多电平换流器子模块能量的不平衡,进而影响模块化多电平变流器型高压直流输电(modular multilevel converter based HVDC, MMC-HVDC)的动态性能。基于不对称交流电网下MMC桥臂瞬时功率的分析,确定换流器内部子模块电容电压及桥臂环流的控制目标。在此基础上,提出一种基于子模块电容电压预估的最近电平调制和基于桥臂环流预估的直接环流控制,两者相结合的复合控制策略。不论交流系统对称与否,在所提出的控制策略下,均能保证换

  17. Available Bandwidth Estimation Strategy Based on the Network Allocation Vector

    Directory of Open Access Journals (Sweden)

    Hongtao Liu

    2012-12-01

    Full Text Available Available bandwidth is of great importance to network Quality of Service assurance, network load balancing, streaming media rate control, routing, and congestion control, etc.. In this paper, the available bandwidth estimation strategy based on the Network Allocation Vector for Wireless Sensor Networks is proposed. According to the size of the average contention window, network nodes predict the probability of collision in process of frame transmission, and then estimate the number of retransmission. Through the collection of Hello packets periodically sent by neighbors, nodes obtain their Network Allocation Vector, and then estimate the available bandwidth. The simulation results show that the strategy is simple and effective, can accurately estimate the collision of data frames as well as the available bandwidth of Wireless Sensor Networks.

  18. Droop Control Strategy for Wind Power Decentralized Integration Based on VSC-HVDC Systems%基于 VSC-HVDC 的风电分散并网下垂控制策略

    Institute of Scientific and Technical Information of China (English)

    田园园; 廖清芬; 刘涤尘; 彭思成; 邹宏亮

    2016-01-01

    With the large-scale development of offshore wind power,the voltage source converter based high voltage direct current(VSC-HVDC) transmission system has received extensive attention in recent years.By introducing the AC voltage droop control,a coordinated multi-terminal grid-connection control strategy for a wind farm AC-dispersed at the sending end based on VSC-HVDC systems is proposed.Based on the traditional control strategy for the flexible HVDC transmission system,the DC voltage control of inverters on the grid side is retained to guarantee system power balance,while AC voltage droop control rather than the original constant-power control is designed for the rectifier on the wind farm side to achieve the advantage of communication-free and reasonable dynamic allocation.Simulation analysis shows that the control strategy proposed is not only able to achieve flexible automatic tracking of rated active power,but also has certain tolerance of load fluctuation and the function of DC/AC fault isolation.And when it comes to power supply for multi-terminal distribution networks by a wind farm AC-dispersed at the sending end,quick power reversal can be achieved if the wind farm is cut out of the system to ensure power supply reliability.And the system is capable of realizing rational allocation of dynamic power automatically among them according to rated ratio,providing effective solutions for coordinated operation of wind farm”s decentralized integration into distribution networks.%海上风电的大规模开发使得柔性直流(VSC-HVDC)输电技术得到了越来越广泛的关注与应用。文中通过引入交流电压下垂控制,提出了基于 VSC-HVDC 的适应送端交流分散模式下的风电场多端并网的协调控制策略。在柔性直流输电传统控制策略的基础上,保留配电网侧逆变器的定直流电压控制,以保证系统功率平衡;而使风电场侧整流器采用交流电压下垂控制,以代替原有的恒功

  19. 基于混合储能的并网光伏电站有功分级控制策略%Active Power Hierarchical Control Strategy of Interconnected Photovoltaic Station Based on Hybrid Energy Storage

    Institute of Scientific and Technical Information of China (English)

    鲍雪娜; 张建成; 徐明; 刘汉民

    2013-01-01

    针对自然条件下光伏电源有功出力的波动性,以超级电容器和磷酸铁锂电池组成的混合储能系统为基础,制定了有功分级控制策略.首先分析了光伏电站整体结构及混合储能装置的接入方式,然后考虑电网需求利用指数平滑法来实时更新光伏电站整体出力参考值,实现第1级控制.根据储能元件能量存储与功率吞吐特性,提出了以超级电容器为充放电主体的混合储能系统能量管理策略,实现第2级控制,并设计了脉宽调制的控制原理电路.编程计算结果证实了所述方法的有效性.%In view of the active power fluctuation of large capacity photovoltaic (PV) power systems, based on a hybrid energy storage system consisting of supercapacitors and lithium-ion ferrous phosphate batteries, an active power hierarchical control strategy is formulated to optimize the output power of PV source. First, the overall structure of photovoltaic power station and the way of accessing the hybrid energy storage system are analyzed. Then, by considering the power grid needs, the exponential smoothing method is used to real-time update the reference values of output power to realize the first level control. The energy management strategy is put forward according to the storage characteristics of energy storage components and power throughput so as to realize the second level control of the hybrid energy storage system. In addition, an energy management strategy is put forward with supercapacitors as the principal part of charge and discharge. Finally, a control circuit of pulse width modulation (PWM) is designed. Programming results demonstrate the effectiveness of the proposed method.

  20. A Space Vector Pulse Width Modulation Based Optimization Control Strategy for Hybrid Cascaded 7-Level Inverter%基于SVPWM调制的混合级联七电平逆变器优化控制策略

    Institute of Scientific and Technical Information of China (English)

    耿俊利; 梁晖; 金渊

    2015-01-01

    The working modes of hybrid cascaded 7-level inverter with dead zone are analyzed and analysis results show that there are different jumping situations of inverter voltage under different working modes. On this basis, based on space vector pulse width modulation (SVPWM) strategy an optimal control method is proposed. In the premise that the supporting capacitor voltage is under the control, through analyzing the jumping of output voltage level and the valve action times corresponding to the charging/discharging process of supporting capacity voltage switching in each interval an optimal control strategy to reduce the jumping of output voltage is put forward; besides, the output voltage loss due to the existence of dead zone time is analyzed and calculated according to the principle of volt-second balance, and the dead zone compensation for its modulation wave is performed. The effectiveness of the proposed control strategy is validated by results of simulation and experiments.%分析混合级联七电平逆变器带死区时的工作模式,不同工作模式下其逆变器电压的跳变情况不同。在此基础上,提出了基于空间矢量脉冲调制(space vector pulse width modulation,SVPWM)策略的优化控制方法。以控制支撑电容电压为前提,通过对每个区间支撑电容充放电切换过程所对应的开关动作次数、输出电压电平跳变情况的分析,提出了一种减小输出电压跳变的优化控制策略;此外,分析了死区时间的存在所带来的输出电压损失,根据伏秒平衡原理进行计算,并对其调制波进行死区补偿。仿真及实验结果验证了该控制策略的有效性。

  1. Permanent Magnet Brushless Motor Control Strategy Based on Switching System Theory%基于切换系统理论的永磁无刷电动机控制策略

    Institute of Scientific and Technical Information of China (English)

    吕永健; 李飞; 李子龙

    2011-01-01

    The switching system is one of the important models which describe the hybrid dynamical systems. Different models and the switching rules are adopted to better describe the motion of the actual complicated systems. Combined with advantages of the PMSM and BLDCM.the paper proposed the switching control strategy for brushless permanent magnet motor with the rule of output feedback based on switching system theory. Then the linear model of the switching control system was obtained and the stability of it was analyzed. The results of the simulation and the experiment show that the switching control strategy is stable and could effectively improve the efficiency and the function of the motor in full speed range.%切换系统是描述混杂动态系统的重要模型之一,采用不同的模态和切换规则可以更好地刻画一个实际复杂动态系统的运行轨迹.基于切换系统理论,结合正弦波和方波电流驱动的永磁无刷电动机的各自优势,提出了按输出状态反馈切换的永磁无刷电动机切换控制策略,建立了切换系统的线性化模型并对其稳定性进行了分析.仿真和实验结果表明,切换控制系统运行稳定,可有效地提高电机全速度范围内的运行效率和性能.

  2. Mothers' teaching strategies and children's effortful control: a longitudinal study.

    Science.gov (United States)

    Eisenberg, Nancy; Vidmar, Masa; Spinrad, Tracy L; Eggum, Natalie D; Edwards, Alison; Gaertner, Bridget; Kupfer, Anne

    2010-09-01

    Findings on the relation of maternal verbal teaching strategies to children's effortful control (EC; i.e., self-regulation) are limited in quantity and somewhat inconsistent. In this study, children's EC was assessed at 18, 30, and 42 months (ns = 255, 229, and 209, respectively) with adults' reports and a behavioral measure. Mothers' verbal teaching strategies were assessed while the mother and child worked on a task together. Children's general vocabulary also was measured. In a structural panel model taking into account prior levels of constructs and correlations within time, as well as the relations of EC and teaching strategies to children's vocabulary, socioeconomic status, age, and sex of the child, 18-month EC positively predicted mothers' 30-month cognitive assistance and questioning strategies and negatively predicted 30-month maternal directive strategies. In addition, high 30-month EC predicted greater 42-month maternal cognitive assistance and fewer directive strategies. Thus, mothers' teaching strategies were predicted by individual differences in self-regulatory skills, supporting potential evocative child effects on mothers' teaching strategies.

  3. Tsetse Control and Gambian Sleeping Sickness; Implications for Control Strategy.

    Directory of Open Access Journals (Sweden)

    Inaki Tirados

    Full Text Available Gambian sleeping sickness (human African trypanosomiasis, HAT outbreaks are brought under control by case detection and treatment although it is recognised that this typically only reaches about 75% of the population. Vector control is capable of completely interrupting HAT transmission but is not used because it is considered too expensive and difficult to organise in resource-poor settings. We conducted a full scale field trial of a refined vector control technology to determine its utility in control of Gambian HAT.The major vector of Gambian HAT is the tsetse fly Glossina fuscipes which lives in the humid zone immediately adjacent to water bodies. From a series of preliminary trials we determined the number of tiny targets required to reduce G. fuscipes populations by more than 90%. Using these data for model calibration we predicted we needed a target density of 20 per linear km of river in riverine savannah to achieve >90% tsetse control. We then carried out a full scale, 500 km2 field trial covering two HAT foci in Northern Uganda to determine the efficacy of tiny targets (overall target density 5.7/km2. In 12 months, tsetse populations declined by more than 90%. As a guide we used a published HAT transmission model and calculated that a 72% reduction in tsetse population is required to stop transmission in those settings.The Ugandan census suggests population density in the HAT foci is approximately 500 per km2. The estimated cost for a single round of active case detection (excluding treatment, covering 80% of the population, is US$433,333 (WHO figures. One year of vector control organised within the country, which can completely stop HAT transmission, would cost US$42,700. The case for adding this method of vector control to case detection and treatment is strong. We outline how such a component could be organised.

  4. The quality of meat from sheep treated with tannin- and saponin-based remedies as a natural strategy for parasite control.

    Science.gov (United States)

    Brogna, D M R; Tansawat, R; Cornforth, D; Ward, R; Bella, M; Luciano, G; Priolo, A; Villalba, J

    2014-02-01

    Lambs were assigned to four groups of seven and treated as follows for 12 days: control group (BP) was fed beet pulp; group T (tannin remedy) received the BP diet including 80 g/kg of quebracho extract; group S (saponin remedy) received the BP diet including 15 g/kg of quillaja extract; and group C had a free choice between T and S remedies. Lipid oxidation was lower in meat from S lambs compared to T lambs (Pmeat from S lambs compared to T animals (P=0.05). Metabolomic analysis showed that the T treatment increased ribose, fructose, glucose and sorbitol concentration in meat (Psheep meat quality.

  5. [Integrated prevention and control strategy for dengue in Mesoamerica].

    Science.gov (United States)

    Gómez-Dantés, Héctor; San Martín, José Luis; Danis-Lozano, Rogelio; Manrique-Saide, Pablo

    2011-01-01

    Dengue in the Americas is a public health problem in ascent. The control strategies have not been effective when sustained in the intensive use of insecticides and poor community participation. The Mesoamerican Initiative for the Prevention and the Integrated Control of Dengue synthesizes the works generated by the Integrated Strategy of the Pan-American Health Organization (PAHO) and the risks stratification strategy designed by the countries of the Mesoamerican region. The objective is to progressively reduce the incidence of dengue cases until a 50% reduction is reached over a five years period. This document describes the elements for the risk stratification, the activities for prevention and control organized by levels of intensity and frequency and the indicators used to pursuit the objectives. To face the dispersion of the problem a concentration of efforts for control in the areas of greater risk is presented; the opportunity in the detection of cases is highlighted to tackle the fast dissemination of the infection; focus on the most productive breeding sites is proposed to battle against the vast dissemination of the breeding sites; and the severity of the infection must be addressed by capable clinical human resources. This strategy was designed along with the national representatives of the control programs to create master plans that provided the basis for the integrated prevention and control of dengue in the Mesoamerican region.

  6. High Level Waste (HLW) Feed Process Control Strategy

    Energy Technology Data Exchange (ETDEWEB)

    STAEHR, T.W.

    2000-06-14

    The primary purpose of this document is to describe the overall process control strategy for monitoring and controlling the functions associated with the Phase 1B high-level waste feed delivery. This document provides the basis for process monitoring and control functions and requirements needed throughput the double-shell tank system during Phase 1 high-level waste feed delivery. This document is intended to be used by (1) the developers of the future Process Control Plan and (2) the developers of the monitoring and control system.

  7. Swedish COBECOS Pilot Study. Costs and Benefits of Control Strategies in selected Swedish fisheries. Final Report

    OpenAIRE

    2013-01-01

    Designing control and enforcement strategies in the fisheries sector to ensure compliance with existing rules is intricate and often hampered by costs. The EU Sixth Framework Programme Project “Costs and benefits of Control Strategies” (COBECOS; https://cobecos.jrc.ec.europa.eu) tackled this impediment to successful fisheries control and enforcement schemes by developing computer based modelling approaches which help to optimise the cost/benefit ratio of envisioned control/enforcement stra...

  8. Comparison of various decentralised structural and cavity feedback control strategies for transmitted noise reduction through a double panel structure

    NARCIS (Netherlands)

    Ho, J.H.; Berkhoff, A.P.

    2014-01-01

    This paper compares various decentralised control strategies, including structural and acoustic actuator-sensor configuration designs, to reduce noise transmission through a double panel structure. The comparison is based on identical control stability indexes. The double panel structure consists of

  9. Integrated control strategies for railway vehicles with independently-driven wheel motors

    Institute of Scientific and Technical Information of China (English)

    Jinzhi FENG; Jun LI; R. M. Goodall

    2008-01-01

    This paper studies the development of inte-grated control strategies for railway vehicles with inde-pendently-driven wheel motors. First, a non-linear vehicle dynamic model and motor drive strategy are pre-sented, which are followed by an investigation of the inte-grated control of stabilization, steering, and traction for the vehicle. Meanwhile a reformulated Kalman filter is developed and applied to estimate the required feedback by the control system. Finally, the effectiveness and prac-ticality of the proposed integrated controller are examined and assessed by real-time simulation based on host-target computer technology provided by Matlab/Simulink.

  10. Assessment of Model Predictive and Adaptive Glucose Control Strategies for People with Type 1 Diabetes

    DEFF Research Database (Denmark)

    Boiroux, Dimitri; Duun-Henriksen, Anne Katrine; Schmidt, Signe;

    2014-01-01

    This paper addresses overnight blood glucose stabilization in people with type 1 diabetes using a Model Predictive Controller (MPC). We use a control strategy based on an adaptive ARMAX model in which we use a Recursive Extended Least Squares (RELS) method to estimate parameters of the stochastic...

  11. Fatigue Analysis of a Wave Energy Converter Taking into Account Different Control Strategies

    DEFF Research Database (Denmark)

    Zurkinden, Andrew Stephen; Lambertsen, Søren Heide; Damkilde, Lars

    2013-01-01

    . In this study, the focus is given on the fatigue damage calculation of a structural detail by taking into account the control parameters of the power take-off system. The predicted fatigue damage is calculated based on the spectral approach. Finally the question will be answered which control strategy is more...

  12. Economic and epidemiological evalution of possible salmonella control strategies in dairy cattle

    NARCIS (Netherlands)

    Bergevoet, R.H.M.; Schaik, van G.; Veling, J.; Backus, G.B.C.; Franken, P.

    2009-01-01

    This paper presents an analysis of a Salmonella control program for Dutch dairy herds. Salmonella control strategies were evaluated using a computer-based model consisting of an epidemiological module and an economics module. The epidemiological module is a state transition model of the infectivity

  13. Design of Energy Storage Control Strategy to Improve the PV System Power Quality

    DEFF Research Database (Denmark)

    Lei, Mingyu; Yang, Zilong; Wang, Yibo

    2016-01-01

    Random fluctuation of PV power is becoming a more and more serious problem affecting the power quality and stability of grid as the PV penetration keeps increasing recent years. Aiming at this problem, this paper proposed a control strategy of energy storage system based on Model Predictive Control...

  14. A Randomized Controlled Dismantling Trial of Post-Workshop Consultation Strategies to Increase Effectiveness and Fidelity to an Evidence-Based Psychotherapy for Posttraumatic Stress Disorder

    Science.gov (United States)

    2013-08-01

    be assessed by trained graduate students and post-doctoral fidelity assessors. Consistent with recommended clinical practice and research trials...measure of clinician attitudes toward EBPs, consisting of 12 factors, with moderate to large factor loadings and fair to excellent internal consistency...methods (i.e., positive deviance ; [65]) that the clinicians deemed helpful in acquiring and maintaining CPT skills. We based our interview questions

  15. Strategies for tobacco control in India: a systematic review.

    Directory of Open Access Journals (Sweden)

    Ailsa J McKay

    Full Text Available Tobacco control needs in India are large and complex. Evaluation of outcomes to date has been limited.To review the extent of tobacco control measures, and the outcomes of associated trialled interventions, in India.Information was identified via database searches, journal hand-searches, reference and citation searching, and contact with experts. Studies of any population resident in India were included. Studies where outcomes were not yet available, not directly related to tobacco use, or not specific to India, were excluded. Pre-tested proformas were used for data extraction and quality assessment. Studies with reliability concerns were excluded from some aspects of analysis. The Framework Convention on Tobacco Control (FCTC was use as a framework for synthesis. Heterogeneity limited meta-analysis options. Synthesis was therefore predominantly narrative.Additional to the Global Tobacco Surveillance System data, 80 studies were identified, 45 without reliability concerns. Most related to education (FCTC Article 12 and tobacco-use cessation (Article 14. They indicated widespread understanding of tobacco-related harm, but less knowledge about specific consequences of use. Healthcare professionals reported low confidence in cessation assistance, in keeping with low levels of training. Training for schoolteachers also appeared suboptimal. Educational and cessation assistance interventions demonstrated positive impact on tobacco use. Studies relating to smoke-free policies (Article 8, tobacco advertisements and availability (Articles 13 and 16 indicated increasingly widespread smoke-free policies, but persistence of high levels of SHS exposure, tobacco promotions and availability-including to minors. Data relating to taxation/pricing and packaging (Articles 6 and 11 were limited. We did not identify any studies of product regulation, alternative employment strategies, or illicit trade (Articles 9, 10, 15 and 17.Tobacco-use outcomes could be improved

  16. Control Systems Cyber Security:Defense in Depth Strategies

    Energy Technology Data Exchange (ETDEWEB)

    David Kuipers; Mark Fabro

    2006-05-01

    Information infrastructures across many public and private domains share several common attributes regarding IT deployments and data communications. This is particularly true in the control systems domain. A majority of the systems use robust architectures to enhance business and reduce costs by increasing the integration of external, business, and control system networks. However, multi-network integration strategies often lead to vulnerabilities that greatly reduce the security of an organization, and can expose mission-critical control systems to cyber threats. This document provides guidance and direction for developing ‘defense-in-depth’ strategies for organizations that use control system networks while maintaining a multi-tier information architecture that requires: Maintenance of various field devices, telemetry collection, and/or industrial-level process systems Access to facilities via remote data link or modem Public facing services for customer or corporate operations A robust business environment that requires connections among the control system domain, the external Internet, and other peer organizations.

  17. A novel control strategy for load converter of DC isolated distribution system under unbalanced loading conditions

    Institute of Scientific and Technical Information of China (English)

    R. NOROOZIAN; M. ABEDI; G.B. GHAREHPETIAN; S. H. HOSSEINI

    2009-01-01

    A novel control strategy for the load converter supplying the unbalanced AC load in a DC isolated distribution system is presented. The control algorithm results in balanced and sinusoidal load voltages under unbalanced AC loading. The unbalanced load is characterized in the d-q-0 rotating coordinate based on symmetrical sequence components. Also, the mathematical model of the load converter in both a-b-c and d-q-0 coordinates is derived by using the average large signal model. Then, two control strategies for the load converter are presented. The first one uses the conventional d-q-0 controller to ensure the voltage and current regulation. The second one is a newly proposed control strategy based on the decomposition of the voltage and current into instantaneous positive, negative, and zero sequences. These three sequences are controlled independently in their own reference frames as DC signals. The performance of the load converter using these two control strategies is compared. Simulation results show the validity and capability of the newly proposed control strategy.

  18. A minimax optimal control strategy for uncertain quasi-Hamiltonian systems

    Institute of Scientific and Technical Information of China (English)

    Yong WANC; Zu-guang YING; Wei-qiu ZHU

    2008-01-01

    A minimax optimal control strategy for quasi-Hamiltonian systems with bounded parametric and/or external disturbances is proposed based on the stochastic averaging method and stochastic differential game. To conduct the system energy control, the partially averaged It6 stochastic differential equations for the energy processes are first derived by using the stochastic averaging method for quasi-Hamiltonian systems. Combining the above equations with an appropriate performance index, the proposed strategy is searching for an optimal worst-case controller by solving a stochastic differential game problem. The worst-case disturbances and the optimal controls are obtained by solving a Hamilton-Jacobi-Isaacs (HJI) equation. Numerical results for a controlled and stochastically excited Duffing oscillator with uncertain disturbances exhibit the efficacy of the proposed control strategy.

  19. Iris Localization Based on Edge Searching Strategies

    Institute of Scientific and Technical Information of China (English)

    Wang Yong; Han Jiuqiang

    2005-01-01

    An iris localization scheme based on edge searching strategies is presented. First, the edge detection operator Laplacian-ofGaussian (LoG) is used to iris original image to search its inner boundary. Then, a circle detection operator is introduced to locate the outer boundary and its center, which is invariant of translation, rotation and scale. Finally, the method of curve fitting is developed in localization of eyelid. The performance of the proposed method is tested with 756 iris images from 108 different classes in CASIA Iris Database and compared with the conventional Hough transform method. The experimental results show that without loss of localization accuracy, the proposed iris localization algorithm is apparently faster than Hough transform.

  20. Linearizing Control of Induction Motor Based on Networked Control Systems

    Institute of Scientific and Technical Information of China (English)

    Jun Ren; Chun-Wen Li; De-Zong Zhao

    2009-01-01

    A new approach to speed control of induction motors is developed by introducing networked control systems (NCSs) into the induction motor driving system. The control strategy is to stabilize and track the rotor speed of the induction motor when the network time delay occurs in the transport medium of network data. First, a feedback linearization method is used to achieve input-output linearization and decoupling control of the induction motor driving system based on rotor flux model, and then the characteristic of network data is analyzed in terms of the inherent network time delay. A networked control model of an induction motor is established. The sufficient condition of asymptotic stability for the networked induction motor driving system is given, and the state feedback controller is obtained by solving the linear matrix inequalities (LMIs). Simulation results verify the efficiency of the proposed scheme.

  1. Model-based control of networked systems

    CERN Document Server

    Garcia, Eloy; Montestruque, Luis A

    2014-01-01

    This monograph introduces a class of networked control systems (NCS) called model-based networked control systems (MB-NCS) and presents various architectures and control strategies designed to improve the performance of NCS. The overall performance of NCS considers the appropriate use of network resources, particularly network bandwidth, in conjunction with the desired response of the system being controlled.   The book begins with a detailed description of the basic MB-NCS architecture that provides stability conditions in terms of state feedback updates . It also covers typical problems in NCS such as network delays, network scheduling, and data quantization, as well as more general control problems such as output feedback control, nonlinear systems stabilization, and tracking control.   Key features and topics include: Time-triggered and event-triggered feedback updates Stabilization of uncertain systems subject to time delays, quantization, and extended absence of feedback Optimal control analysis and ...

  2. An Efficient Modal Control Strategy for the Active Vibration Control of a Truss Structure

    Directory of Open Access Journals (Sweden)

    Ricardo Carvalhal

    2007-01-01

    Full Text Available In this paper an efficient modal control strategy is described for the active vibration control of a truss structure. In this approach, a feedback force is applied to each mode to be controlled according to a weighting factor that is determined by assessing how much each mode is excited by the primary source. The strategy is effective provided that the primary source is at a fixed position on the structure, and that the source is stationary in the statistical sense. To test the effectiveness of the control strategy it is compared with an alternative, established approach namely, Independent Modal Space Control (IMSC. Numerical simulations show that with the new strategy it is possible to significantly reduce the control effort required, with a minimal reduction in control performance.

  3. Vote Centers as a Strategy to Control Election Administration Costs

    Directory of Open Access Journals (Sweden)

    David H. Folz

    2014-03-01

    Full Text Available The rising costs of election administration in an era of fiscal stress have motivated some local officials to test the feasibility of ideas for reducing election costs while enhancing voter convenience and perhaps even increasing voter turnout. One such pilot project in a suburban community in the South involved replacing precinct-based voting on election day with a vote center that all voters could use regardless of their precinct of residence. A comparison of election costs across two municipal elections showed that replacing precinct-based voting with an election day vote center resulted in substantial cost savings. While there was no statistical difference in voter turnout in municipal elections held before and after implementation of the pilot project, voters were highly satisfied with the convenience of the vote center as well as other aspects of their voting experience. The findings suggest that an election day vote center can be a viable strategy to control election costs and enhance voters’ perceptions of the convenience of voting.

  4. Active control strategy on a catenary-pantograph validated model

    Science.gov (United States)

    Sanchez-Rebollo, C.; Jimenez-Octavio, J. R.; Carnicero, A.

    2013-04-01

    Dynamic simulation methods have become essential in the design process and control of the catenary-pantograph system, overall since high-speed trains and interoperability criteria are getting very trendy. This paper presents an original hardware-in-the-loop (HIL) strategy aimed at integrating a multicriteria active control within the catenary-pantograph dynamic interaction. The relevance of HIL control systems applied in the frame of the pantograph is undoubtedly increasing due to the recent and more demanding requirements for high-speed railway systems. Since the loss of contact between the catenary and the pantograph leads to arcing and electrical wear, and too high contact forces cause mechanical wear of both the catenary wires and the strips of the pantograph, not only prescribed but also economic and performance criteria ratify such a relevance. Different configurations of the proportional-integral-derivative (PID) controller are proposed and applied to two different plant systems. Since this paper is mainly focused on the control strategy, both plant systems are simulation models though the methodology is suitable for a laboratory bench. The strategy of control involves a multicriteria optimisation of the contact force and the consumption of the energy supplied by the control force, a genetic algorithm has been applied for this purpose. Thus, the PID controller is fitted according to these conflicting objectives and tested within a nonlinear lumped model and a nonlinear finite element model, being the last one validated against the European Standard EN 50318. Finally, certain tests have been accomplished in order to analyse the robustness of the control strategy. Particularly, the relevance or the plant simulation, the running speed and the instrumentation time delay are studied in this paper.

  5. Control strategies used in the control software for the Heavy Ion Research Facility in Lanzhou

    Science.gov (United States)

    Zhou, Wen-Xiong; Wang, Yan-Yu; Pan, Liang-Ming; Tu, Sheng-Pan

    2016-07-01

    Automation control systems are important for the operation of an accelerator. To ensure the reliable, stable and flexible operation of the Heavy Ion Research Facility in Lanzhou (HIRFL), several control systems are developed. The developed control systems are the SECRAL control system, the LECR3 control system, the LAPECR1 control system and the Electro-Static septum control system. The corresponding control software systems are developed using Visual C++. To ensure the accuracy, stability and flexibility of the control systems, some special control strategies are developed in the control software systems. This paper provides a detailed description of the main control strategies used in the control software systems. The main control strategies are composed of a reliable communication mechanism, a correct data/command transmission mechanism, an efficient data storage mechanism and an interlock protection mechanism. To guarantee a reliable communication between the devices for the commercially purchased devices and the built in-house ones, a modified heartbeat method is developed. To provide flexible reconstitution function for the control systems, the command queue and the state machine are combined. The message mechanism and the multiple windows mechanism are also used for the module mechanism. The relevant control systems are introduced as examples of these control strategies. These systems have been running stably for several years.

  6. Composite braking control strategy of pure electric bus based on brake driving intention recognition%基于制动驾驶意图辨识的纯电动客车复合制动控制策略

    Institute of Scientific and Technical Information of China (English)

    赵轩; 马建; 汪贵平

    2014-01-01

    To research braking force distribution ratio of composite braking system for pure electric bus,a composite braking control strategy based on brake driving intention recognition was presented.A double-layer brake driving intention recognition model based on hidden Markov theory was set up and identified by using road experiment data.Based on recognized driving intention and vehicle speed,the distribution ratios of braking forces for front and rear wheels, ECE regulation, motor characteristics, slip ratios, battery characteristics, super capacitor characteristics and transmission system characteristics were taken as constraint conditions,the braking force distribution strategy of composite braking system was proposed,and the control strategy of composite braking system was simulated by Simulink software under 9 operating conditions.Simulation result shows that friction braking system and motor regenerative braking system can work coordinately and steadily under various operating conditions when the braking control strategy is applied,and braking energy can be recovered as much as possible under the premise of ensuring braking safety.Energy recovery efficiency is highest under slight brake when vehicle speed was low,and the efficiency can reach to 43 .84%.Energy recovery efficiency is lowest under emergency brake when vehicle speed is high,and the efficiency is only 0. 89%. 2 tabs,21 figs,23 refs.%为了研究纯电动客车复合制动系统制动力分配比例,提出了基于制动驾驶意图辨识的复合制动控制策略。基于隐形马尔科夫理论建立了双层制动驾驶意图辨识模型,运用道路试验数据对模型进行辨识验证。基于辨识出的驾驶意图和车速,以前后轮制动力分配比例、ECE 法规、电机特性、滑移率、蓄电池特性、超级电容特性与传动系统特性为约束条件,制定了复合制动系统制动力分配策略,在9种工况下,应用Simulink对复合制动系统进行建

  7. Cloud-based Networked Visual Servo Control

    DEFF Research Database (Denmark)

    Wu, Haiyan; Lu, Lei; Chen, Chih-Chung

    2013-01-01

    The performance of vision-based control systems, in particular of highly dynamic vision-based motion control systems, is often limited by the low sampling rate of the visual feedback caused by the long image processing time. In order to overcome this problem, the networked visual servo control......, which integrates networked computational resources for cloud image processing, is considered in this article. The main contributions of this article are i) a real-time transport protocol for transmitting large volume image data on a cloud computing platform, which enables high sampling rate visual...... feedback, ii) a stabilizing control law for the networked visual servo control system with time-varying feedback time delay, and iii) a sending rate scheduling strategy aiming at reducing the communication network load. The performance of the networked visual servo control system with sending rate...

  8. STRATEGIES OF PRODUCTION CONTROL AS TOOLS OF EFFICIENT MANAGEMENT OF PRODUCTION ENTERPRISES

    Directory of Open Access Journals (Sweden)

    Mateusz BUDYNEK

    2016-01-01

    Full Text Available The paper discusses the problem of principle methods of production control as a strategy supporting the production system and stimulating efficient solutions in respect management in production enterprises. The article describes MRP, ERP, JIT, KANBAN and TOC methods and focuses on their main goals, principles of functioning as well as benefits re-sulting from their application. The methods represent two diverse strategies of production control, i.e. pull and push strategies. Push strategies are used when the plans apply to the first and principle part of production and are based on the demand forecasts. Pull strategies are used when all planning decisions apply to the final stage and depend on the actual demand or orders from customers.

  9. Control Strategy for Microgrid Inverter under Unbalanced Grid Voltage Conditions

    DEFF Research Database (Denmark)

    Guo, Xiaoqiang; Liu, Wenzhao; Zhang, X.

    2014-01-01

    This paper presents the theoretical analysis of the inherent reason of current harmonic and power oscillation phenomena in case of operating the microgrid inverter under unbalanced grid voltage conditions. In order to flexibly control the current harmonic and power oscillation, a new stationary...... frame control strategy is proposed. It has a simple control structure due to no need of a phase-locked loop and voltage/current positive/negative sequence extraction calculation. The coordinate control of power and current quality is achieved, which enhances the operation performance of microgrid...

  10. A Combined Cooperative Braking Model with a Predictive Control Strategy in an Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Hongqiang Guo

    2013-12-01

    Full Text Available Cooperative braking with regenerative braking and mechanical braking plays an important role in electric vehicles for energy-saving control. Based on the parallel and the series cooperative braking models, a combined model with a predictive control strategy to get a better cooperative braking performance is presented. The balance problem between the maximum regenerative energy recovery efficiency and the optimum braking stability is solved through an off-line process optimization stream with the collaborative optimization algorithm (CO. To carry out the process optimization stream, the optimal Latin hypercube design (Opt LHD is presented to discrete the continuous design space. To solve the poor real-time problem of the optimization, a high-precision predictive model based on the off-line optimization data of the combined model is built, and a predictive control strategy is proposed and verified through simulation. The simulation results demonstrate that the predictive control strategy and the combined model are reasonable and effective.

  11. Study and experimental verification of control tuning strategies in a variable speed wind energy conversion system

    Energy Technology Data Exchange (ETDEWEB)

    Zaragoza, Jordi; Pou, Josep; Arias, Antoni [Electronic Engineering Dept., Technical University of Catalonia, Campus Terrassa, C. Colom 1, 08222 Terrassa (Spain); Spiteri, Cyril [Department of Industrial Electrical Power Conversion, University of Malta, Faculty of Engineering, Msida (Malta); Robles, Eider; Ceballos, Salvador [Energy Unit, Robotiker-Tecnalia Technology Corporation, Zamudio, Basque Country (Spain)

    2011-05-15

    This paper analyzes and compares different control tuning strategies for a variable speed wind energy conversion system (WECS) based on a permanent-magnet synchronous generator (PMSG). The aerodynamics of the wind turbine (WT) and a PMSG have been modeled. The control strategy used in this research is composed of three regulators, which may be based on either linear or nonlinear controllers. In this analysis, proportional-integral (PI) linear controllers have been used. Two different tuning strategies are analyzed and compared. The main goal is to enhance the overall performance by achieving a low sensitivity to disturbances and minimal overshoot under variable operating conditions. Finally, the results have been verified by an experimental WECS laboratory prototype. (author)

  12. Control strategies for demand controlled ventilation in dwellings

    DEFF Research Database (Denmark)

    Nielsen, Toke Rammer; Drivsholm, Christian

    2011-01-01

    Ventilation of Danish and many other European dwellings has in the past mainly been achieved by natural ventilation or mechanical exhaust systems. Requirements for energy efficiency is changing this picture and mechanical ventilation with balanced exhaust and supply, efficient heat recovery...... high. Too low ventilation rate results in poor air quality for the occupants and moisture risk. Too high ventilation rate results in unnecessary energy consumption. This paper presents results from a study where demand controlled ventilation was installed in an existing single family house...... was possible. The results showed that the ventilation rate in periods can be reduced significantly without significant increase in moisture or CO2-concentration....

  13. Unfalsified control based on the ? controller parameterisation

    Science.gov (United States)

    Sánchez-Peña, R. S.; Colmegna, P.; Bianchi, F.

    2015-11-01

    This paper presents an implementation of the unfalsified control (UC) method using the Riccati-based parameterisation of ? controllers. The method provides an infinite controller set to (un)falsify the real-time data streams seeking for the best performance. Different sets may be designed to increase the degrees of freedom of the set of controller candidates to perform UC. In general, a set of m central controllers could be designed, each one seeking different objectives and all with their own parameterisation as a function of a stable and bounded transfer matrix. For example, one controller parameterisation could be designed to solve the robust stability of a model set which covers the physical system, therefore guaranteeing feasibility. The implementation requires the online optimisation of either quadratic fractional or quadratic problems, depending on the selection of the cost function. A multi-input, multi-output (MIMO) time-varying model of a permanent magnet synchronous generator illustrates the use of this technique.

  14. Control Strategy and Experiment of High Voltage Ride Through for DFIG-based Wind Turbines%双馈风电机组高电压穿越控制策略与试验

    Institute of Scientific and Technical Information of China (English)

    李少林; 王伟胜; 王瑞明; 孙勇; 陈晨

    2016-01-01

    In research of frequent tripping of wind turbines under high voltage conditions , the requirements for high voltage ride through ( HVRT) of the main grid integration guide to wind power are introduced . A comparative analysis of electromagnetic transient characteristics of doubly‐fed induction generator (DFIG) based wind turbines is carried out under dip and voltage swell conditions , and the full control of the DFIG‐based wind turbines HVRT process is demonstrated if the voltage is less than 1 .3 nominal voltage . Then , a collaborative HVRT control strategy for DFIG‐based wind turbines based on main controller and the convertor is proposed , which is implemented just by software improvement without hardware modification , and avoids the adverse effect of Crowbar or Chopper protection action on the characteristics of HVRT . A 2 MW DFIG‐based wind turbines model for HVRT research is built in MATLAB/Simulink , and the HVRT process of DFIG‐based wind turbines is simulated . The field test is carried out on a 2 MW DFIG‐based wind turbines by high voltage generator for the first time . The simulation and experimental results support the theoretical analysis and verifies the effectiveness of the proposed control strategy .%针对风电的高电压脱网问题,介绍了主要风电并网导则对高电压穿越的要求,对比分析了双馈风电机组低电压和高电压的电磁暂态特性,论证了双馈风电机组1.3倍额定电压的高电压穿越过程全程可控的可行性。提出了一种基于双馈变流器动态无功控制的高电压穿越控制策略和风电机组主控系统与变流器协同控制完成高电压穿越的实现方法,避免了 Crowbar 或 Chopper 保护动作对高电压穿越特性的不利影响。在 MATLAB/Simulink 中建立了2 MW 双馈风电机组高电压穿越仿真模型,实现了高电压穿越全过程仿真;利用高电压发生装置,在2 MW 双馈风电机组上进行了高电压穿越

  15. Utilization-Based Congestion Control

    OpenAIRE

    Satoshi Utsumi; Salahuddin Muhammad Salim Zabir

    2012-01-01

    Traditional connection oriented protocols like TCP NewReno perform poorly over wireless links. Theproblem lies in their design assumptions based on loss based congestion control. Various modificationsto loss based congestion control schemes have so far been proposed to overcome the issue. In addition,the comparatively newer family of delay based congestion control mechanisms like Caia-Hamilton Delay(CHD), offer effective solutions for wireless link loss. All these approaches aim at improving ...

  16. Control Strategies for HCCI Mixed-Mode Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Robert M [ORNL; Edwards, Kevin Dean [ORNL

    2010-03-01

    Delphi Automotive Systems and ORNL established this CRADA to expand the operational range of Homogenous Charge Compression Ignition (HCCI) mixed-mode combustion for gasoline en-gines. ORNL has extensive experience in the analysis, interpretation, and control of dynamic engine phenomena, and Delphi has extensive knowledge and experience in powertrain compo-nents and subsystems. The partnership of these knowledge bases was important to address criti-cal barriers associated with the realistic implementation of HCCI and enabling clean, efficient operation for the next generation of transportation engines. The foundation of this CRADA was established through the analysis of spark-assisted HCCI data from a single-cylinder research engine. This data was used to (1) establish a conceptual kinetic model to better understand and predict the development of combustion instabilities, (2) develop a low-order model framework suitable for real-time controls, and (3) provide guidance in the initial definition of engine valve strategies for achieving HCCI operation. The next phase focused on the development of a new combustion metric for real-time characterization of the combustion process. Rapid feedback on the state of the combustion process is critical to high-speed decision making for predictive control. Simultaneous to the modeling/analysis studies, Delphi was focused on the development of engine hardware and the engine management system. This included custom Delphi hardware and control systems allowing for flexible control of the valvetrain sys-tem to enable HCCI operation. The final phase of this CRADA included the demonstration of conventional and spark assisted HCCI on the multi-cylinder engine as well as the characterization of combustion instabilities, which govern the operational boundaries of this mode of combustion. ORNL and Delphi maintained strong collaboration throughout this project. Meetings were held on a bi-weekly basis with additional reports, presentation, and

  17. Managing Work and Family: Do Control Strategies Help?

    Science.gov (United States)

    Versey, H. Shellae

    2015-01-01

    How can we effectively manage competing obligations from work and family without becoming overwhelmed? This question inspires the current study by examining control strategies that may facilitate better work-life balance, with a specific focus on the role of lowered aspirations and positive reappraisals, attitudes that underlie adaptive coping…

  18. Control strategies for brushless doubly fed reluctance machines

    OpenAIRE

    Jovanovic, Milutin; Betz, Robert

    2001-01-01

    Paper presents the development and results of comprehensive comparative analysis of different vector control strategies for performance optimisation of the BDFRM being considered as a viable cost-effective brushless alternative to traditional brush and less reliable solutions in applications with limited variable speed ranges (such as wind turbines). Australian Research Council and EPSRC projects.

  19. 40 CFR 52.282 - Control strategy and regulations: Ozone.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy and regulations: Ozone... and regulations: Ozone. (a) Attainment determination. EPA has determined that the Ventura County severe 1-hour ozone nonattainment area attained the 1-hour ozone NAAQS by the applicable attainment...

  20. 40 CFR 52.1683 - Control strategy: Ozone.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Ozone. 52.1683...: Ozone. (a) The State of New York has certified to the satisfaction of the EPA that no sources are... Polystyrene Resins. (b)-(e) (f) Attainment Determination. (1) EPA is determining that the 1-hour...