On-line diagnostic techniques for air-operated control valves based on time series analysis

International Nuclear Information System (INIS)

Ito, Kenji; Matsuoka, Yoshinori; Minamikawa, Shigeru; Komatsu, Yasuki; Satoh, Takeshi.

1996-01-01

The objective of this research is to study the feasibility of applying on-line diagnostic techniques based on time series analysis to air-operated control valves - numerous valves of the type which are used in PWR plants. Generally the techniques can detect anomalies by failures in the initial stages for which detection is difficult by conventional surveillance of process parameters measured directly. However, the effectiveness of these techniques depends on the system being diagnosed. The difficulties in applying diagnostic techniques to air-operated control valves seem to come from the reduced sensitivity of their response as compared with hydraulic control systems, as well as the need to identify anomalies in low level signals that fluctuate only slightly but continuously. In this research, simulation tests were performed by setting various kinds of failure modes for a test valve with the same specifications as of a valve actually used in the plants. Actual control signals recorded from an operating plant were then used as input signals for simulation. The results of the tests confirmed the feasibility of applying on-line diagnostic techniques based on time series analysis to air-operated control valves. (author)

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.

Analysis of control rod behavior based on numerical simulation

International Nuclear Information System (INIS)

Ha, D. G.; Park, J. K.; Park, N. G.; Suh, J. M.; Jeon, K. L.

2010-01-01

The main function of a control rod is to control core reactivity change during operation associated with changes in power, coolant temperature, and dissolved boron concentration by the insertion and withdrawal of control rods from the fuel assemblies. In a scram, the control rod assemblies are released from the CRDMs (Control Rod Drive Mechanisms) and, due to gravity, drop rapidly into the fuel assemblies. The control rod insertion time during a scram must be within the time limits established by the overall core safety analysis. To assure the control rod operational functions, the guide thimbles shall not obstruct the insertion and withdrawal of the control rods or cause any damage to the fuel assembly. When fuel assembly bow occurs, it can affect both the operating performance and the core safety. In this study, the drag forces of the control rod are estimated by a numerical simulation to evaluate the guide tube bow effect on control rod withdrawal. The contact condition effects are also considered. A full scale 3D model is developed for the evaluation, and ANSYS - commercial numerical analysis code - is used for this numerical simulation. (authors)

Principal components analysis based control of a multi-dof underactuated prosthetic hand

Directory of Open Access Journals (Sweden)

Magenes Giovanni

2010-04-01

Full Text Available Abstract Background Functionality, controllability and cosmetics are the key issues to be addressed in order to accomplish a successful functional substitution of the human hand by means of a prosthesis. Not only the prosthesis should duplicate the human hand in shape, functionality, sensorization, perception and sense of body-belonging, but it should also be controlled as the natural one, in the most intuitive and undemanding way. At present, prosthetic hands are controlled by means of non-invasive interfaces based on electromyography (EMG. Driving a multi degrees of freedom (DoF hand for achieving hand dexterity implies to selectively modulate many different EMG signals in order to make each joint move independently, and this could require significant cognitive effort to the user. Methods A Principal Components Analysis (PCA based algorithm is used to drive a 16 DoFs underactuated prosthetic hand prototype (called CyberHand with a two dimensional control input, in order to perform the three prehensile forms mostly used in Activities of Daily Living (ADLs. Such Principal Components set has been derived directly from the artificial hand by collecting its sensory data while performing 50 different grasps, and subsequently used for control. Results Trials have shown that two independent input signals can be successfully used to control the posture of a real robotic hand and that correct grasps (in terms of involved fingers, stability and posture may be achieved. Conclusions This work demonstrates the effectiveness of a bio-inspired system successfully conjugating the advantages of an underactuated, anthropomorphic hand with a PCA-based control strategy, and opens up promising possibilities for the development of an intuitively controllable hand prosthesis.

Research on Robot Pose Control Technology Based on Kinematics Analysis Model

Science.gov (United States)

Liu, Dalong; Xu, Lijuan

2018-01-01

In order to improve the attitude stability of the robot, proposes an attitude control method of robot based on kinematics analysis model, solve the robot walking posture transformation, grasping and controlling the motion planning problem of robot kinematics. In Cartesian space analytical model, using three axis accelerometer, magnetometer and the three axis gyroscope for the combination of attitude measurement, the gyroscope data from Calman filter, using the four element method for robot attitude angle, according to the centroid of the moving parts of the robot corresponding to obtain stability inertia parameters, using random sampling RRT motion planning method, accurate operation to any position control of space robot, to ensure the end effector along a prescribed trajectory the implementation of attitude control. The accurate positioning of the experiment is taken using MT-R robot as the research object, the test robot. The simulation results show that the proposed method has better robustness, and higher positioning accuracy, and it improves the reliability and safety of robot operation.

Analysis of a quantum memory for photons based on controlled reversible inhomogeneous broadening

International Nuclear Information System (INIS)

Sangouard, Nicolas; Simon, Christoph; Afzelius, Mikael; Gisin, Nicolas

2007-01-01

We present a detailed analysis of a quantum memory for photons based on controlled and reversible inhomogeneous broadening. The explicit solution of the equations of motion is obtained in the weak excitation regime, making it possible to gain insight into the dependence of the memory efficiency on the optical depth, and on the width and shape of the atomic spectral distributions. We also study a simplified memory protocol which does not require any optical control fields

Power consumption analysis of pump station control systems based on fuzzy controllers with discrete terms in iThink software

Science.gov (United States)

Muravyova, E. A.; Bondarev, A. V.; Sharipov, M. I.; Galiaskarova, G. R.; Kubryak, A. I.

2018-03-01

In this article, power consumption of pumping station control systems is discussed. To study the issue, two simulation models of oil level control in the iThink software have been developed, using a frequency converter only and using a frequency converter and a fuzzy controller. A simulation of the oil-level control was carried out in a graphic form, and plots of pumps power consumption were obtained. Based on the initial and obtained data, the efficiency of the considered control systems has been compared, and also the power consumption of the systems was shown graphically using a frequency converter only and using a frequency converter and a fuzzy controller. The models analysis has shown that it is more economical and safe to use a control circuit with a frequency converter and a fuzzy controller.

Controllability analysis of decentralised linear controllers for polymeric fuel cells

Energy Technology Data Exchange (ETDEWEB)

Serra, Maria; Aguado, Joaquin; Ansede, Xavier; Riera, Jordi [Institut de Robotica i Informatica Industrial, Universitat Politecnica de Catalunya - Consejo Superior de Investigaciones Cientificas, C. Llorens i Artigas 4, 08028 Barcelona (Spain)

2005-10-10

This work deals with the control of polymeric fuel cells. It includes a linear analysis of the system at different operating points, the comparison and selection of different control structures, and the validation of the controlled system by simulation. The work is based on a complex non linear model which has been linearised at several operating points. The linear analysis tools used are the Morari resiliency index, the condition number, and the relative gain array. These techniques are employed to compare the controllability of the system with different control structures and at different operating conditions. According to the results, the most promising control structures are selected and their performance with PI based diagonal controllers is evaluated through simulations with the complete non linear model. The range of operability of the examined control structures is compared. Conclusions indicate good performance of several diagonal linear controllers. However, very few have a wide operability range. (author)

Space construction base control system

Science.gov (United States)

1978-01-01

Aspects of an attitude control system were studied and developed for a large space base that is structurally flexible and whose mass properties change rather dramatically during its orbital lifetime. Topics of discussion include the following: (1) space base orbital pointing and maneuvering; (2) angular momentum sizing of actuators; (3) momentum desaturation selection and sizing; (4) multilevel control technique applied to configuration one; (5) one-dimensional model simulation; (6) N-body discrete coordinate simulation; (7) structural analysis math model formulation; and (8) discussion of control problems and control methods.

Robust Stability Clearance of Flight Control Law Based on Global Sensitivity Analysis

OpenAIRE

Ou, Liuli; Liu, Lei; Dong, Shuai; Wang, Yongji

2014-01-01

To validate the robust stability of the flight control system of hypersonic flight vehicle, which suffers from a large number of parametrical uncertainties, a new clearance framework based on structural singular value ( $\\mu $ ) theory and global uncertainty sensitivity analysis (SA) is proposed. In this framework, SA serves as the preprocess of uncertain model to be analysed to help engineers to determine which uncertainties affect the stability of the closed loop system more slightly. By ig...

Stability Analysis of Positive Polynomial Fuzzy-Model-Based Control Systems with Time Delay under Imperfect Premise Matching

OpenAIRE

Li, Xiaomiao; Lam, Hak Keung; Song, Ge; Liu, Fucai

2017-01-01

This paper deals with the stability and positivity analysis of polynomial-fuzzy-model-based ({PFMB}) control systems with time delay, which is formed by a polynomial fuzzy model and a polynomial fuzzy controller connected in a closed loop, under imperfect premise matching. To improve the design and realization flexibility, the polynomial fuzzy model and the polynomial fuzzy controller are allowed to have their own set of premise membership functions. A sum-of-squares (SOS)-based stability ana...

78 FR 64425 - Current Good Manufacturing Practice and Hazard Analysis and Risk-Based Preventive Controls for...

Science.gov (United States)

2013-10-29

..., 507, and 579 [Docket No. FDA-2011-N-0922] Current Good Manufacturing Practice and Hazard Analysis and... requirements for current good manufacturing practice and hazard analysis and risk-based preventive controls for..., packing, or holding of animal food in two ways. First, it would create new current good manufacturing...

Plan delivery quality assurance for CyberKnife: Statistical process control analysis of 350 film-based patient-specific QAs.

Science.gov (United States)

Bellec, J; Delaby, N; Jouyaux, F; Perdrieux, M; Bouvier, J; Sorel, S; Henry, O; Lafond, C

2017-07-01

Robotic radiosurgery requires plan delivery quality assurance (DQA) but there has never been a published comprehensive analysis of a patient-specific DQA process in a clinic. We proposed to evaluate 350 consecutive film-based patient-specific DQAs using statistical process control. We evaluated the performance of the process to propose achievable tolerance criteria for DQA validation and we sought to identify suboptimal DQA using control charts. DQAs were performed on a CyberKnife-M6 using Gafchromic-EBT3 films. The signal-to-dose conversion was performed using a multichannel-correction and a scanning protocol that combined measurement and calibration in a single scan. The DQA analysis comprised a gamma-index analysis at 3%/1.5mm and a separate evaluation of spatial and dosimetric accuracy of the plan delivery. Each parameter was plotted on a control chart and control limits were calculated. A capability index (Cpm) was calculated to evaluate the ability of the process to produce results within specifications. The analysis of capability showed that a gamma pass rate of 85% at 3%/1.5mm was highly achievable as acceptance criteria for DQA validation using a film-based protocol (Cpm>1.33). 3.4% of DQA were outside a control limit of 88% for gamma pass-rate. The analysis of the out-of-control DQA helped identify a dosimetric error in our institute for a specific treatment type. We have defined initial tolerance criteria for DQA validations. We have shown that the implementation of a film-based patient-specific DQA protocol with the use of control charts is an effective method to improve patient treatment safety on CyberKnife. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Weld analysis and control system

Science.gov (United States)

Kennedy, Larry Z. (Inventor); Rodgers, Michael H. (Inventor); Powell, Bradley W. (Inventor); Burroughs, Ivan A. (Inventor); Goode, K. Wayne (Inventor)

1994-01-01

The invention is a Weld Analysis and Control System developed for active weld system control through real time weld data acquisition. Closed-loop control is based on analysis of weld system parameters and weld geometry. The system is adapted for use with automated welding apparatus having a weld controller which is capable of active electronic control of all aspects of a welding operation. Enhanced graphics and data displays are provided for post-weld analysis. The system provides parameter acquisition, including seam location which is acquired for active torch cross-seam positioning. Torch stand-off is also monitored for control. Weld bead and parent surface geometrical parameters are acquired as an indication of weld quality. These parameters include mismatch, peaking, undercut, underfill, crown height, weld width, puddle diameter, and other measurable information about the weld puddle regions, such as puddle symmetry, etc. These parameters provide a basis for active control as well as post-weld quality analysis and verification. Weld system parameters, such as voltage, current and wire feed rate, are also monitored and archived for correlation with quality parameters.

Frame-based safety analysis approach for decision-based errors

International Nuclear Information System (INIS)

Fan, Chin-Feng; Yihb, Swu

1997-01-01

A frame-based approach is proposed to analyze decision-based errors made by automatic controllers or human operators due to erroneous reference frames. An integrated framework, Two Frame Model (TFM), is first proposed to model the dynamic interaction between the physical process and the decision-making process. Two important issues, consistency and competing processes, are raised. Consistency between the physical and logic frames makes a TFM-based system work properly. Loss of consistency refers to the failure mode that the logic frame does not accurately reflect the state of the controlled processes. Once such failure occurs, hazards may arise. Among potential hazards, the competing effect between the controller and the controlled process is the most severe one, which may jeopardize a defense-in-depth design. When the logic and physical frames are inconsistent, conventional safety analysis techniques are inadequate. We propose Frame-based Fault Tree; Analysis (FFTA) and Frame-based Event Tree Analysis (FETA) under TFM to deduce the context for decision errors and to separately generate the evolution of the logical frame as opposed to that of the physical frame. This multi-dimensional analysis approach, different from the conventional correctness-centred approach, provides a panoramic view in scenario generation. Case studies using the proposed techniques are also given to demonstrate their usage and feasibility

78 FR 24691 - Current Good Manufacturing Practice and Hazard Analysis and Risk-Based Preventive Controls for...

Science.gov (United States)

2013-04-26

... comments should be identified with the title ``Current Good Manufacturing Practice and Hazard Analysis and..., 114, 117, 120, 123, 129, 179, and 211 [Docket No. FDA-2011-N-0920] RIN 0910-AG36 Current Good Manufacturing Practice and Hazard Analysis and Risk- Based Preventive Controls for Human Food; Extension of...

Developments in model-based optimization and control distributed control and industrial applications

CERN Document Server

Grancharova, Alexandra; Pereira, Fernando

2015-01-01

This book deals with optimization methods as tools for decision making and control in the presence of model uncertainty. It is oriented to the use of these tools in engineering, specifically in automatic control design with all its components: analysis of dynamical systems, identification problems, and feedback control design. Developments in Model-Based Optimization and Control takes advantage of optimization-based formulations for such classical feedback design objectives as stability, performance and feasibility, afforded by the established body of results and methodologies constituting optimal control theory. It makes particular use of the popular formulation known as predictive control or receding-horizon optimization. The individual contributions in this volume are wide-ranging in subject matter but coordinated within a five-part structure covering material on: · complexity and structure in model predictive control (MPC); · collaborative MPC; · distributed MPC; · optimization-based analysis and desi...

Passivity-Based Control of Electric Machines

Energy Technology Data Exchange (ETDEWEB)

Nicklasson, P.J.

1996-12-31

This doctoral thesis presents new results on the design and analysis of controllers for a class of electric machines. Nonlinear controllers are derived from a Lagrangian model representation using passivity techniques, and previous results on induction motors are improved and extended to Blondel-Park transformable machines. The relation to conventional techniques is discussed, and it is shown that the formalism introduced in this work facilitates analysis of conventional methods, so that open questions concerning these methods may be resolved. In addition, the thesis contains the following improvements of previously published results on the control of induction motors: (1) Improvement of a passivity-based speed/position controller, (2) Extension of passivity-based (observer-less and observer-based) controllers from regulation to tracking of rotor flux norm, (3) An extension of the classical indirect FOC (Field-Oriented Control) scheme to also include global rotor flux norm tracking, instead of only torque tracking and rotor flux norm regulation. The design is illustrated experimentally by applying the proposed control schemes to a squirrel-cage induction motor. The results show that the proposed methods have advantages over previous designs with respect to controller tuning, performance and robustness. 145 refs., 21 figs.

Magnetic Field Equivalent Current Analysis-Based Radial Force Control for Bearingless Permanent Magnet Synchronous Motors

Directory of Open Access Journals (Sweden)

Huangqiu Zhu

2015-05-01

Full Text Available Bearingless permanent magnet synchronous motors (BPMSMs, with all advantages of permanent magnet motors (PMSMs and magnetic bearings, have become an important research direction in the bearingless motor field. To realize a stable suspension for the BPMSM, accurate decoupling control between the electromagnetic torque and radial suspension force is indispensable. In this paper, a concise and reliable analysis method based on a magnetic field equivalent current is presented. By this analysis method, the operation principle is analyzed theoretically, and the necessary conditions to produce a stable radial suspension force are confirmed. In addition, mathematical models of the torque and radial suspension force are established which is verified by the finite element analysis (FEA software ANSYS. Finally, an experimental prototype of a 2-4 poles surface-mounted BPMSM is tested with the customized control strategy. The simulation and experimental results have shown that the motor has good rotation and suspension performance, and validated the accuracy of the proposed analysis method and the feasibility of the control strategy.

Robust Stability Clearance of Flight Control Law Based on Global Sensitivity Analysis

Directory of Open Access Journals (Sweden)

Liuli Ou

2014-01-01

Full Text Available To validate the robust stability of the flight control system of hypersonic flight vehicle, which suffers from a large number of parametrical uncertainties, a new clearance framework based on structural singular value (μ theory and global uncertainty sensitivity analysis (SA is proposed. In this framework, SA serves as the preprocess of uncertain model to be analysed to help engineers to determine which uncertainties affect the stability of the closed loop system more slightly. By ignoring these unimportant uncertainties, the calculation of μ can be simplified. Instead of analysing the effect of uncertainties on μ which involves solving optimal problems repeatedly, a simpler stability analysis function which represents the effect of uncertainties on closed loop poles is proposed. Based on this stability analysis function, Sobol’s method, the most widely used global SA method, is extended and applied to the new clearance framework due to its suitability for system with strong nonlinearity and input factors varying in large interval, as well as input factors subjecting to random distributions. In this method, the sensitive indices can be estimated via Monte Carlo simulation conveniently. An example is given to illustrate the efficiency of the proposed method.

Effectiveness of Internet-Based Interventions on Glycemic Control in Patients With Type 2 Diabetes: Meta-Analysis of Randomized Controlled Trials

Science.gov (United States)

Shen, Ying; Wang, Fengbin; Zhang, Xing; Zhu, Xiaorou; Sun, Qiudan; Fisher, Edwin

2018-01-01

Background The popularity of internet as an area of research has grown manifold over the years. Given its rapid development and increasing coverage worldwide, internet-based interventions seem to offer a promising option to ameliorate huge burdens brought by type 2 diabetes mellitus. However, studies conducted by different researchers have provided contradictory results on the effect of internet-based interventions in glycemic control. Objective This meta-analysis aims to summarize currently available evidence and evaluate the overall impact of internet-based interventions on glycemic management of type 2 diabetic patients. Methods A systematic literature search was performed in PubMed, ScienceDirect, and Web of Science. Randomized controlled trials that used glycosylated hemoglobin values as the outcome measure of glycemic control were considered. Risk of bias and publication bias were evaluated. Results Of the 492 studies, 35 were included in meta-analysis, and results indicated that the weighted mean difference (WMD) between usual care and internet-based interventions at endpoint was –0.426% (95% CI –0.540 to –0.312; P<.001). Subgroup analyses revealed that intervention duration ≤3 months yielded optimal performance (WMD –0.51%; 95% CI –0.71 to –0.31; P<.001). Combined mobile and website interventions were substantially superior to solely Web-based and mobile-based interventions in glycemic control (combined WMD –0.77%, 95% CI –1.07 to –0.47; P<.001; Web only: WMD –0.48%; 95% CI –0.71 to –0.24, P<.001; mobile only WMD –0.31%, 95% CI –0.49 to –0.14; P<.001). Furthermore, the effect of interventions with automated feedbacks was similar to those with manual feedbacks, and studies with internet-based educational contents were more effective in glycemic control. The assessment revealed a low risk of bias. Conclusions In conclusion, utilization of internet-based intervention is beneficial for patients with type 2 diabetes mellitus, and

Effectiveness of Internet-Based Interventions on Glycemic Control in Patients With Type 2 Diabetes: Meta-Analysis of Randomized Controlled Trials.

Science.gov (United States)

Shen, Ying; Wang, Fengbin; Zhang, Xing; Zhu, Xiaorou; Sun, Qiudan; Fisher, Edwin; Sun, Xinying

2018-05-07

The popularity of internet as an area of research has grown manifold over the years. Given its rapid development and increasing coverage worldwide, internet-based interventions seem to offer a promising option to ameliorate huge burdens brought by type 2 diabetes mellitus. However, studies conducted by different researchers have provided contradictory results on the effect of internet-based interventions in glycemic control. This meta-analysis aims to summarize currently available evidence and evaluate the overall impact of internet-based interventions on glycemic management of type 2 diabetic patients. A systematic literature search was performed in PubMed, ScienceDirect, and Web of Science. Randomized controlled trials that used glycosylated hemoglobin values as the outcome measure of glycemic control were considered. Risk of bias and publication bias were evaluated. Of the 492 studies, 35 were included in meta-analysis, and results indicated that the weighted mean difference (WMD) between usual care and internet-based interventions at endpoint was -0.426% (95% CI -0.540 to -0.312; P<.001). Subgroup analyses revealed that intervention duration ≤3 months yielded optimal performance (WMD -0.51%; 95% CI -0.71 to -0.31; P<.001). Combined mobile and website interventions were substantially superior to solely Web-based and mobile-based interventions in glycemic control (combined WMD -0.77%, 95% CI -1.07 to -0.47; P<.001; Web only: WMD -0.48%; 95% CI -0.71 to -0.24, P<.001; mobile only WMD -0.31%, 95% CI -0.49 to -0.14; P<.001). Furthermore, the effect of interventions with automated feedbacks was similar to those with manual feedbacks, and studies with internet-based educational contents were more effective in glycemic control. The assessment revealed a low risk of bias. In conclusion, utilization of internet-based intervention is beneficial for patients with type 2 diabetes mellitus, and taking full advantage of this type of intervention may substantially reduce the

Dynamic Allan Variance Analysis Method with Time-Variant Window Length Based on Fuzzy Control

Directory of Open Access Journals (Sweden)

Shanshan Gu

2015-01-01

Full Text Available To solve the problem that dynamic Allan variance (DAVAR with fixed length of window cannot meet the identification accuracy requirement of fiber optic gyro (FOG signal over all time domains, a dynamic Allan variance analysis method with time-variant window length based on fuzzy control is proposed. According to the characteristic of FOG signal, a fuzzy controller with the inputs of the first and second derivatives of FOG signal is designed to estimate the window length of the DAVAR. Then the Allan variances of the signals during the time-variant window are simulated to obtain the DAVAR of the FOG signal to describe the dynamic characteristic of the time-varying FOG signal. Additionally, a performance evaluation index of the algorithm based on radar chart is proposed. Experiment results show that, compared with different fixed window lengths DAVAR methods, the change of FOG signal with time can be identified effectively and the evaluation index of performance can be enhanced by 30% at least by the DAVAR method with time-variant window length based on fuzzy control.

Model-based analysis and control of a network of basal ganglia spiking neurons in the normal and Parkinsonian states

Science.gov (United States)

Liu, Jianbo; Khalil, Hassan K.; Oweiss, Karim G.

2011-08-01

Controlling the spatiotemporal firing pattern of an intricately connected network of neurons through microstimulation is highly desirable in many applications. We investigated in this paper the feasibility of using a model-based approach to the analysis and control of a basal ganglia (BG) network model of Hodgkin-Huxley (HH) spiking neurons through microstimulation. Detailed analysis of this network model suggests that it can reproduce the experimentally observed characteristics of BG neurons under a normal and a pathological Parkinsonian state. A simplified neuronal firing rate model, identified from the detailed HH network model, is shown to capture the essential network dynamics. Mathematical analysis of the simplified model reveals the presence of a systematic relationship between the network's structure and its dynamic response to spatiotemporally patterned microstimulation. We show that both the network synaptic organization and the local mechanism of microstimulation can impose tight constraints on the possible spatiotemporal firing patterns that can be generated by the microstimulated network, which may hinder the effectiveness of microstimulation to achieve a desired objective under certain conditions. Finally, we demonstrate that the feedback control design aided by the mathematical analysis of the simplified model is indeed effective in driving the BG network in the normal and Parskinsonian states to follow a prescribed spatiotemporal firing pattern. We further show that the rhythmic/oscillatory patterns that characterize a dopamine-depleted BG network can be suppressed as a direct consequence of controlling the spatiotemporal pattern of a subpopulation of the output Globus Pallidus internalis (GPi) neurons in the network. This work may provide plausible explanations for the mechanisms underlying the therapeutic effects of deep brain stimulation (DBS) in Parkinson's disease and pave the way towards a model-based, network level analysis and closed

75 FR 8239 - School Food Safety Program Based on Hazard Analysis and Critical Control Point Principles (HACCP...

Science.gov (United States)

2010-02-24

... (HACCP); Approval of Information Collection Request AGENCY: Food and Nutrition Service, USDA. ACTION... Safety Program Based on Hazard Analysis and Critical Control Point Principles (HACCP) was published on... must be based on the (HACCP) system established by the Secretary of Agriculture. The food safety...

Budgeting-Based Organization of Internal Control

Science.gov (United States)

Rogulenko, Tatiana; Ponomareva, Svetlana; Bodiaco, Anna; Mironenko, Valentina; Zelenov, Vladimir

2016-01-01

The article suggests methodical approaches to the budgeting-based organization of internal control, determines the tasks and subtasks of control that consist in the construction of an efficient system for the making, implementation, control, and analysis of managerial decisions. The organization of responsibility centers by means of implementing…

Stabilization of nonlinear systems using sampled-data output-feedback fuzzy controller based on polynomial-fuzzy-model-based control approach.

Science.gov (United States)

Lam, H K

2012-02-01

This paper investigates the stability of sampled-data output-feedback (SDOF) polynomial-fuzzy-model-based control systems. Representing the nonlinear plant using a polynomial fuzzy model, an SDOF fuzzy controller is proposed to perform the control process using the system output information. As only the system output is available for feedback compensation, it is more challenging for the controller design and system analysis compared to the full-state-feedback case. Furthermore, because of the sampling activity, the control signal is kept constant by the zero-order hold during the sampling period, which complicates the system dynamics and makes the stability analysis more difficult. In this paper, two cases of SDOF fuzzy controllers, which either share the same number of fuzzy rules or not, are considered. The system stability is investigated based on the Lyapunov stability theory using the sum-of-squares (SOS) approach. SOS-based stability conditions are obtained to guarantee the system stability and synthesize the SDOF fuzzy controller. Simulation examples are given to demonstrate the merits of the proposed SDOF fuzzy control approach.

Intelligent Control in Automation Based on Wireless Traffic Analysis

Energy Technology Data Exchange (ETDEWEB)

Kurt Derr; Milos Manic

2007-08-01

Wireless technology is a central component of many factory automation infrastructures in both the commercial and government sectors, providing connectivity among various components in industrial realms (distributed sensors, machines, mobile process controllers). However wireless technologies provide more threats to computer security than wired environments. The advantageous features of Bluetooth technology resulted in Bluetooth units shipments climbing to five million per week at the end of 2005 [1, 2]. This is why the real-time interpretation and understanding of Bluetooth traffic behavior is critical in both maintaining the integrity of computer systems and increasing the efficient use of this technology in control type applications. Although neuro-fuzzy approaches have been applied to wireless 802.11 behavior analysis in the past, a significantly different Bluetooth protocol framework has not been extensively explored using this technology. This paper presents a new neurofuzzy traffic analysis algorithm of this still new territory of Bluetooth traffic. Further enhancements of this algorithm are presented along with the comparison against the traditional, numerical approach. Through test examples, interesting Bluetooth traffic behavior characteristics were captured, and the comparative elegance of this computationally inexpensive approach was demonstrated. This analysis can be used to provide directions for future development and use of this prevailing technology in various control type applications, as well as making the use of it more secure.

Intelligent Control in Automation Based on Wireless Traffic Analysis

Energy Technology Data Exchange (ETDEWEB)

Kurt Derr; Milos Manic

2007-09-01

Wireless technology is a central component of many factory automation infrastructures in both the commercial and government sectors, providing connectivity among various components in industrial realms (distributed sensors, machines, mobile process controllers). However wireless technologies provide more threats to computer security than wired environments. The advantageous features of Bluetooth technology resulted in Bluetooth units shipments climbing to five million per week at the end of 2005 [1, 2]. This is why the real-time interpretation and understanding of Bluetooth traffic behavior is critical in both maintaining the integrity of computer systems and increasing the efficient use of this technology in control type applications. Although neuro-fuzzy approaches have been applied to wireless 802.11 behavior analysis in the past, a significantly different Bluetooth protocol framework has not been extensively explored using this technology. This paper presents a new neurofuzzy traffic analysis algorithm of this still new territory of Bluetooth traffic. Further enhancements of this algorithm are presented along with the comparison against the traditional, numerical approach. Through test examples, interesting Bluetooth traffic behavior characteristics were captured, and the comparative elegance of this computationally inexpensive approach was demonstrated. This analysis can be used to provide directions for future development and use of this prevailing technology in various control type applications, as well as making the use of it more secure.

Motion Intention Analysis-Based Coordinated Control for Amputee-Prosthesis Interaction

Directory of Open Access Journals (Sweden)

Fei Wang

2010-01-01

Full Text Available To study amputee-prosthesis (AP interaction, a novel reconfigurable biped robot was designed and fabricated. In homogeneous configuration, two identical artificial legs (ALs were used to simulate the symmetrical lower limbs of a healthy person. Linear inverted pendulum model combining with ZMP stability criterion was used to generate the gait trajectories of ALs. To acquire interjoint coordination for healthy gait, rate gyroscopes were mounted on CoGs of thigh and shank of both legs. By employing principal component analysis, the measured angular velocities were processed and the motion synergy was obtained in the final. Then, one of two ALs was replaced by a bionic leg (BL, and the biped robot was changed into heterogeneous configuration to simulate the AP coupling system. To realize symmetrical stable walking, master/slave coordinated control strategy is proposed. According to information acquired by gyroscopes, BL recognized the motion intention of AL and reconstructed its kinematic variables based on interjoint coordination. By employing iterative learning control, gait tracking of BL to AL was archived. Real environment robot walking experiments validated the correctness and effectiveness of the proposed scheme.

Modeling and the analysis of control logic for a digital PWM controller based on a nano electronic single electron transistor

Directory of Open Access Journals (Sweden)

Rathnakannan Kailasam

2008-01-01

Full Text Available This paper describes the modelling and the analysis of control logic for a Nano-Device- based PWM controller. A comprehensive simple SPICE schematic model for Single Electron transistor has been proposed. The operation of basic Single Electron Transistor logic gates and SET flip flops were successfully designed and their performances analyzed. The proposed design for realizing the logic gates and flip-flops is used in constructing the PWM controller utilized for switching the buck converter circuit. The output of the converter circuit is compared with reference voltage, and when the error voltage and the reference are matched the latch is reset so as to generate the PWM signal. Due to the simplicity and accuracy of the compact model, the simulation time and speed are much faster, which makes it potentially applicable in large-scale circuit simulation. This study confirms that the SET-based PWM controller is small in size, consumes ultra low power and operates at high speeds without compromising any performance. In addition these devices are capable of measuring charges of extremely high sensitivity.

Stability Analysis for Car Following Model Based on Control Theory

International Nuclear Information System (INIS)

Meng Xiang-Pei; Li Zhi-Peng; Ge Hong-Xia

2014-01-01

Stability analysis is one of the key issues in car-following theory. The stability analysis with Lyapunov function for the two velocity difference car-following model (for short, TVDM) is conducted and the control method to suppress traffic congestion is introduced. Numerical simulations are given and results are consistent with the theoretical analysis. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Experiment-Based Teaching in Advanced Control Engineering

Science.gov (United States)

Precup, R.-E.; Preitl, S.; Radac, M.-B.; Petriu, E. M.; Dragos, C.-A.; Tar, J. K.

2011-01-01

This paper discusses an experiment-based approach to teaching an advanced control engineering syllabus involving controlled plant analysis and modeling, control structures and algorithms, real-time laboratory experiments, and their assessment. These experiments are structured around the representative case of the longitudinal slip control of an…

Impedance Based Analysis and Design of Harmonic Resonant Controller for a Wide Range of Grid Impedance

DEFF Research Database (Denmark)

Kwon, Jun Bum; Wang, Xiongfei; Blaabjerg, Frede

2014-01-01

This paper investigates the effect of grid impedance variation on harmonic resonant current controllers for gridconnected voltage source converters by means of impedance-based analysis. It reveals that the negative harmonic resistances tend to be derived from harmonic resonant controllers...... in the closed-loop output admittance of converter. Such negative resistances may interact with the grid impedance resulting in steady state error or unstable harmonic compensation. To deal with this problem, a design guideline for harmonic resonant controllers under a wide range of grid impedance is proposed...

Predictor-Based Model Reference Adaptive Control

Science.gov (United States)

Lavretsky, Eugene; Gadient, Ross; Gregory, Irene M.

2010-01-01

This paper is devoted to the design and analysis of a predictor-based model reference adaptive control. Stable adaptive laws are derived using Lyapunov framework. The proposed architecture is compared with the now classical model reference adaptive control. A simulation example is presented in which numerical evidence indicates that the proposed controller yields improved transient characteristics.

Quantum control mechanism analysis through field based Hamiltonian encoding

International Nuclear Information System (INIS)

Mitra, Abhra; Rabitz, Herschel

2006-01-01

Optimal control of quantum dynamics in the laboratory is proving to be increasingly successful. The control fields can be complex, and the mechanisms by which they operate have often remained obscure. Hamiltonian encoding (HE) has been proposed as a method for understanding mechanisms in quantum dynamics. In this context mechanism is defined in terms of the dominant quantum pathways leading to the final state of the controlled system. HE operates by encoding a special modulation into the Hamiltonian and decoding its signature in the dynamics to determine the dominant pathway amplitudes. Earlier work encoded the modulation directly into the Hamiltonian operators. This present work introduces the alternative scheme of field based HE, where the modulation is encoded into the control field and not directly into the Hamiltonian operators. This distinct form of modulation yields a new perspective on mechanism and is computationally faster than the earlier approach. Field based encoding is also an important step towards a laboratory based algorithm for HE as it is the only form of encoding that may be experimentally executed. HE is also extended to cover systems with noise and uncertainty and finally, a hierarchical algorithm is introduced to reveal mechanism in a stepwise fashion of ever increasing detail as desired. This new hierarchical algorithm is an improvement over earlier approaches to HE where the entire mechanism was determined in one stroke. The improvement comes from the use of less complex modulation schemes, which leads to fewer evaluations of Schroedinger's equation. A number of simulations are presented on simple systems to illustrate the new field based encoding technique for mechanism assessment

Analysis and control of nonlinear systems a flatness-based approach

CERN Document Server

Levine, Jean

2009-01-01

This book examines control of nonlinear systems. Coverage ranges from mathematical system theory to practical industrial control applications. The author offers web-based videos illustrating some dynamical aspects and case studies in simulation.

Robustness analysis of chiller sequencing control

International Nuclear Information System (INIS)

Liao, Yundan; Sun, Yongjun; Huang, Gongsheng

2015-01-01

Highlights: • Uncertainties with chiller sequencing control were systematically quantified. • Robustness of chiller sequencing control was systematically analyzed. • Different sequencing control strategies were sensitive to different uncertainties. • A numerical method was developed for easy selection of chiller sequencing control. - Abstract: Multiple-chiller plant is commonly employed in the heating, ventilating and air-conditioning system to increase operational feasibility and energy-efficiency under part load condition. In a multiple-chiller plant, chiller sequencing control plays a key role in achieving overall energy efficiency while not sacrifices the cooling sufficiency for indoor thermal comfort. Various sequencing control strategies have been developed and implemented in practice. Based on the observation that (i) uncertainty, which cannot be avoided in chiller sequencing control, has a significant impact on the control performance and may cause the control fail to achieve the expected control and/or energy performance; and (ii) in current literature few studies have systematically addressed this issue, this paper therefore presents a study on robustness analysis of chiller sequencing control in order to understand the robustness of various chiller sequencing control strategies under different types of uncertainty. Based on the robustness analysis, a simple and applicable method is developed to select the most robust control strategy for a given chiller plant in the presence of uncertainties, which will be verified using case studies

Screening in veterinary drug analysis and sports doping control based on full-scan, accurate-mass spectrometry

NARCIS (Netherlands)

Peters, R.J.B.; Stolker, A.A.M.; Mol, J.G.J.; Lommen, A.; Lyris, E.; Angelis, Y.S.; Vonaparti, A.; Stamou, M.; Georgakopoulos, C.G.; Nielen, M.W.F.

2010-01-01

A common trend in food contaminants and sports doping control is towards a limited number of targeted, full-scan, accurate-mass spectrometry (MS) methods based on time-of-flight (TOF) or Fourier-transform orbital trap (Orbitrap) mass analyzers. Retrospective analysis of the full-scan datasets of

Model-based specification, analysis and synthesis of servo controllers for lithoscanners

NARCIS (Netherlands)

Schiffelers, R.; Alberts, W.; Voeten, J.P.M.

2012-01-01

ASML is the world's leading provider of complex lithography systems for the semiconductor industry. Such systems consist of numerous servo control systems. To design such control systems, a multi-disciplinary model-based development environment has been developed. It is based on a set of domain

Parametric Analysis of Flexible Logic Control Model

Directory of Open Access Journals (Sweden)

Lihua Fu

2013-01-01

Full Text Available Based on deep analysis about the essential relation between two input variables of normal two-dimensional fuzzy controller, we used universal combinatorial operation model to describe the logic relationship and gave a flexible logic control method to realize the effective control for complex system. In practical control application, how to determine the general correlation coefficient of flexible logic control model is a problem for further studies. First, the conventional universal combinatorial operation model has been limited in the interval [0,1]. Consequently, this paper studies a kind of universal combinatorial operation model based on the interval [a,b]. And some important theorems are given and proved, which provide a foundation for the flexible logic control method. For dealing reasonably with the complex relations of every factor in complex system, a kind of universal combinatorial operation model with unequal weights is put forward. Then, this paper has carried out the parametric analysis of flexible logic control model. And some research results have been given, which have important directive to determine the values of the general correlation coefficients in practical control application.

Physically consistent data assimilation method based on feedback control for patient-specific blood flow analysis.

Science.gov (United States)

Ii, Satoshi; Adib, Mohd Azrul Hisham Mohd; Watanabe, Yoshiyuki; Wada, Shigeo

2018-01-01

This paper presents a novel data assimilation method for patient-specific blood flow analysis based on feedback control theory called the physically consistent feedback control-based data assimilation (PFC-DA) method. In the PFC-DA method, the signal, which is the residual error term of the velocity when comparing the numerical and reference measurement data, is cast as a source term in a Poisson equation for the scalar potential field that induces flow in a closed system. The pressure values at the inlet and outlet boundaries are recursively calculated by this scalar potential field. Hence, the flow field is physically consistent because it is driven by the calculated inlet and outlet pressures, without any artificial body forces. As compared with existing variational approaches, although this PFC-DA method does not guarantee the optimal solution, only one additional Poisson equation for the scalar potential field is required, providing a remarkable improvement for such a small additional computational cost at every iteration. Through numerical examples for 2D and 3D exact flow fields, with both noise-free and noisy reference data as well as a blood flow analysis on a cerebral aneurysm using actual patient data, the robustness and accuracy of this approach is shown. Moreover, the feasibility of a patient-specific practical blood flow analysis is demonstrated. Copyright © 2017 John Wiley & Sons, Ltd.

Subcubic Control Flow Analysis Algorithms

DEFF Research Database (Denmark)

Midtgaard, Jan; Van Horn, David

We give the first direct subcubic algorithm for performing control flow analysis of higher-order functional programs. Despite the long held belief that inclusion-based flow analysis could not surpass the ``cubic bottleneck, '' we apply known set compression techniques to obtain an algorithm...... that runs in time O(n^3/log n) on a unit cost random-access memory model machine. Moreover, we refine the initial flow analysis into two more precise analyses incorporating notions of reachability. We give subcubic algorithms for these more precise analyses and relate them to an existing analysis from...

[Powdered infant formulae preparation guide for hospitals based on Hazard Analysis and Critical Control Points (HACCP) principles].

Science.gov (United States)

Vargas-Leguás, H; Rodríguez Garrido, V; Lorite Cuenca, R; Pérez-Portabella, C; Redecillas Ferreiro, S; Campins Martí, M

2009-06-01

This guide for the preparation of powdered infant formulae in hospital environments is a collaborative work between several hospital services and is based on national and European regulations, international experts meetings and the recommendations of scientific societies. This guide also uses the Hazard Analysis and Critical Control Point principles proposed by Codex Alimentarius and emphasises effective verifying measures, microbiological controls of the process and the corrective actions when monitoring indicates that a critical control point is not under control. It is a dynamic guide and specifies the evaluation procedures that allow it to be constantly adapted.

A rotordynamic analysis of circumferentially-grooved pump seals based on a three-control-volume theory

International Nuclear Information System (INIS)

Ha, Tae Woong; Lee, An Sung

2000-01-01

In this paper the leakage prediction and rotordynamic analysis of an annular seal with a smooth rotor and circumferentially grooved stator are performed based on a three-control-volume theory. The present analysis is validated by comparing with the experimental data of Iwatsubo and Sheng and theoretical results suggested by Marquette and Childs. For the leakage prediction the present analysis shows a good agreement with Marquette and Childs' result and a qualitation agreement with Iwatsubo and Shengs' experimental data. Direct and cross-coupled stiffness coefficients show closer agreement with the experimental values than those of Marquette and Childs. However, direct damping coefficient shows greater discrepancy from the experimental value than Marquette and Childs'

Effects of Pharmacy-Based Interventions on the Control and Management of Diabetes in Adults: A Systematic Review and Meta-Analysis.

Science.gov (United States)

Yaghoubi, Mohsen; Mansell, Kerry; Vatanparastc, Hassanali; Steeves, Megan; Zeng, Wu; Farag, Marwa

2017-12-01

The aim of this systematic review and meta-analysis was to evaluate the effects of pharmacy-based interventions on clinical outcomes associated with diabetes-related complications as well as on nonclinical outcomes in people with diabetes. We searched 4 main databases (MEDLINE, EMBASE, CINAHL and Cochrane Central Register of Controlled Trials) for studies that considered clinical and nonclinical outcomes of pharmacy-based interventions among people with diabetes. Clinical outcomes included patients' mean reductions of glycated hemoglobin (A1C) levels and body mass indexes (BMIs). Nonclinical outcomes included patients' healthcare utilization and quality of life. A meta-analysis was conducted to estimate the pooled net mean difference in clinical outcomes between the pharmacy-intervention and the control groups. Of the 44 studies included in the systematic review, 32 studies reported results from randomized controlled trials measuring reductions of A1C levels in 4,132 patients. Meta-analysis revealed that the standardized absolute mean difference in reduction of A1C levels from baseline to the time of the last follow up significantly favoured the pharmacy intervention versus the control group (0.96%; 95% CI 0.71 to 1.22; p<0.001). Of the studies, 13 reported BMI kg/m 2 in 1,827 patients. The estimation of standardized absolute mean difference in reduction of BMI unit calculated through meta-analysis was 0.61 (95% CI 0.20 to 1.03; p=0.000) in favour of the pharmacy-intervention group. Pharmacy-based interventions have significant positive effects on controlling 2 major risks factors associated with diabetes-related complications: A1C levels and BMI. However, there is a dearth of evidence about the effects of pharmacy-based intervention on nonclinical outcomes, including healthcare utilization and quality of life. Copyright © 2017 Diabetes Canada. Published by Elsevier Inc. All rights reserved.

Kinematics Control and Analysis of Industrial Robot

Science.gov (United States)

Zhu, Tongbo; Cai, Fan; Li, Yongmei; Liu, Wei

2018-03-01

The robot’s development present situation, basic principle and control system are introduced briefly. Research is mainly focused on the study of the robot’s kinematics and motion control. The structural analysis of a planar articulated robot (SCARA) robot is presented,the coordinate system is established to obtain the position and orientation matrix of the end effector,a method of robot kinematics analysis based on homogeneous transformation method is proposed, and the kinematics solution of the robot is obtained.Establishment of industrial robot’s kinematics equation and formula for positive kinematics by example. Finally,the kinematic analysis of this robot was verified by examples.It provides a basis for structural design and motion control.It has active significance to promote the motion control of industrial robot.

Control and communication co-design: analysis and practice on performance improvement in distributed measurement and control system based on fieldbus and Ethernet.

Science.gov (United States)

Liang, Geng

2015-01-01

In this paper, improving control performance of a networked control system by reducing DTD in a different perspective was investigated. Two different network architectures for system implementation were presented. Analysis and improvement dealing with DTD for the experimental control system were expounded. Effects of control scheme configuration on DTD in the form of FB were investigated and corresponding improvements by reallocation of FB and re-arrangement of schedule table are proposed. Issues of DTD in hybrid network were investigated and corresponding approaches to improve performance including (1) reducing DTD in PLC or PAC by way of IEC61499 and (2) cascade Smith predictive control with BPNN-based identification were proposed and investigated. Control effects under the proposed methodologies were also given. Experimental and field practices validated these methodologies. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Interdisciplinary analysis procedures in the modeling and control of large space-based structures

Science.gov (United States)

Cooper, Paul A.; Stockwell, Alan E.; Kim, Zeen C.

1987-01-01

The paper describes a computer software system called the Integrated Multidisciplinary Analysis Tool, IMAT, that has been developed at NASA Langley Research Center. IMAT provides researchers and analysts with an efficient capability to analyze satellite control systems influenced by structural dynamics. Using a menu-driven interactive executive program, IMAT links a relational database to commercial structural and controls analysis codes. The paper describes the procedures followed to analyze a complex satellite structure and control system. The codes used to accomplish the analysis are described, and an example is provided of an application of IMAT to the analysis of a reference space station subject to a rectangular pulse loading at its docking port.

Cost-effectiveness analysis of population-based tobacco control strategies in the prevention of cardiovascular diseases in Tanzania.

Directory of Open Access Journals (Sweden)

Frida Ngalesoni

Full Text Available Tobacco consumption contributes significantly to the global burden of disease. The prevalence of smoking is estimated to be increasing in many low-income countries, including Tanzania, especially among women and youth. Even so, the implementation of tobacco control measures has been discouraging in the country. Efforts to foster investment in tobacco control are hindered by lack of evidence on what works and at what cost.We aim to estimate the cost and cost-effectiveness of population-based tobacco control strategies in the prevention of cardiovascular diseases (CVD in Tanzania.A cost-effectiveness analysis was performed using an Excel-based Markov model, from a governmental perspective. We employed an ingredient approach and step-down methodologies in the costing exercise following a government perspective. Epidemiological data and efficacy inputs were derived from the literature. We used disability-adjusted life years (DALYs averted as the outcome measure. A probabilistic sensitivity analysis was carried out with Ersatz to incorporate uncertainties in the model parameters.Our model results showed that all five tobacco control strategies were very cost-effective since they fell below the ceiling ratio of one GDP per capita suggested by the WHO. Increase in tobacco taxes was the most cost-effective strategy, while a workplace smoking ban was the least cost-effective option, with a cost-effectiveness ratio of US$5 and US$267, respectively.Even though all five interventions are deemed very cost-effective in the prevention of CVD in Tanzania, more research on budget impact analysis is required to further assess the government's ability to implement these interventions.

OPTIMIZATION OF THE TEMPERATURE CONTROL SCHEME FOR ROLLER COMPACTED CONCRETE DAMS BASED ON FINITE ELEMENT AND SENSITIVITY ANALYSIS METHODS

Directory of Open Access Journals (Sweden)

Huawei Zhou

2016-10-01

Full Text Available Achieving an effective combination of various temperature control measures is critical for temperature control and crack prevention of concrete dams. This paper presents a procedure for optimizing the temperature control scheme of roller compacted concrete (RCC dams that couples the finite element method (FEM with a sensitivity analysis method. In this study, seven temperature control schemes are defined according to variations in three temperature control measures: concrete placement temperature, water-pipe cooling time, and thermal insulation layer thickness. FEM is employed to simulate the equivalent temperature field and temperature stress field obtained under each of the seven designed temperature control schemes for a typical overflow dam monolith based on the actual characteristics of a RCC dam located in southwestern China. A sensitivity analysis is subsequently conducted to investigate the degree of influence each of the three temperature control measures has on the temperature field and temperature tensile stress field of the dam. Results show that the placement temperature has a substantial influence on the maximum temperature and tensile stress of the dam, and that the placement temperature cannot exceed 15 °C. The water-pipe cooling time and thermal insulation layer thickness have little influence on the maximum temperature, but both demonstrate a substantial influence on the maximum tensile stress of the dam. The thermal insulation thickness is significant for reducing the probability of cracking as a result of high thermal stress, and the maximum tensile stress can be controlled under the specification limit with a thermal insulation layer thickness of 10 cm. Finally, an optimized temperature control scheme for crack prevention is obtained based on the analysis results.

Development of a data base system for quality control of MOX fuels

International Nuclear Information System (INIS)

Takahashi, Kuniaki; Yamaguchi, Toshihiro; Mishima, Takeshi

1988-01-01

For the purpose of improvement and speed up of work concerning quality control for mixed oxide fuel fabrication, we have been developing a data base system having a data base consisting of data as to fabrication conditions and inspects, We have aimed to develop a data base system having capability of analysis and function giving informations as to quality control. The data base system is full interactive system on real time basis, consequently it makes analyzing and editing data easy. It has capability of relational research, numerical analysis, correlation analysis, drawing control charts, histograms, and other figures, and expressing status of fabrication processes using control charts. (author)

Financial Analysis, Budgeting, Decision and Control

Directory of Open Access Journals (Sweden)

Mariana Rodica TIRLEA

2013-12-01

Full Text Available The economic processes taking place in the economic environment are stochastic processes that involve and imply risks, arising from product diversification, competition, financial derivatives transactions: swaps, futures, options and from the large number of actors involved in the stock market with a higher or a smaller uncertainty degree. Competition and competitiveness, led to major and rapid change in the business environment, they determined actors participating in the economy to find solutions and methods of collecting and processing data, in such a way that, after being transformed into information they quickly help based on their analysis in decision making, planning and financial forecasting, having an effect on increasing their economic efficiency. In these circumstances the financial analysis, decision, forecasting and control, should be based on quality information that should be a value creation source. The active nature of the financial function implies the existence of a substantially large share of financial analysis, financial decision, forecasting and control.

Analysis and control of chaotic behavior in boost converter by ramp compensation based on Lyapunov exponents assignment: theoretical and experimental investigation

International Nuclear Information System (INIS)

Zamani, Najmeh; Ataei, Mohammad; Niroomand, Mehdi

2015-01-01

Highlights: • Applying nonlinear analysis of complex dynamics displayed by current-mode controlled boost converter. • The ramp compensation method is used to control bifurcation and chaos in these converters based on bifurcation diagram and Lyapunov exponents assignment. • A discrete-time iterative nonlinear mapping model has been derived by inserting the ramp compensation parameter in the dynamical equations of the system. • A design methodology for chaos control is provided in this converter based on Lyapunov exponents assignment in desired values theoretically by proper selection of compensator slope. • Practical results are provided to confirm the theoretical analysis and simulations. - Abstract: Nonlinear analysis of complex dynamics displayed by current mode dc–dc converter and idea of Lyapunov exponents assignment by ramp compensator in order to control chaotic behavior is proposed in this article. A discrete-time iterative nonlinear mapping model is derived. The occurrence of the complex behaviors of bifurcation and chaos generated by varying the circuit parameters are investigated through numerical analysis and software implementation of the circuit. Next, in order to control bifurcation and chaos in these converters, the ramp compensation method is used. By inserting the ramp compensation parameter in the dynamical equations of the system, these complex behaviors are examined theoretically and numerically as well. It is proved that through this method, the stable period-one operation of the converter can be extended. By evaluating the Lyapunov exponents (LEs) of the system, the impact of the slope on the location of LEs are determined analytically. This leads to a design methodology for control of chaos in this converter based on LEs assignment in desired values by proper selection of compensator slope. By developing an experimental set up, practical results are obtained to confirm the theoretical analysis and simulations.

Solar Dynamic Power System Stability Analysis and Control

Science.gov (United States)

Momoh, James A.; Wang, Yanchun

1996-01-01

The objective of this research is to conduct dynamic analysis, control design, and control performance test of solar power system. Solar power system consists of generation system and distribution network system. A bench mark system is used in this research, which includes a generator with excitation system and governor, an ac/dc converter, six DDCU's and forty-eight loads. A detailed model is used for modeling generator. Excitation system is represented by a third order model. DDCU is represented by a seventh order system. The load is modeled by the combination of constant power and constant impedance. Eigen-analysis and eigen-sensitivity analysis are used for system dynamic analysis. The effects of excitation system, governor, ac/dc converter control, and the type of load on system stability are discussed. In order to improve system transient stability, nonlinear ac/dc converter control is introduced. The direct linearization method is used for control design. The dynamic analysis results show that these controls affect system stability in different ways. The parameter coordination of controllers are recommended based on the dynamic analysis. It is concluded from the present studies that system stability is improved by the coordination of control parameters and the nonlinear ac/dc converter control stabilize system oscillation caused by the load change and system fault efficiently.

Software design specification and analysis(NuFDS) approach for the safety critical software based on porgrammable logic controller(PLC)

International Nuclear Information System (INIS)

Koo, Seo Ryong; Seong, Poong Hyun; Jung, Jin Yong; Choi, Seong Soo

2004-01-01

This paper introduces the software design specification and analysis technique for the safety-critical system based on Programmable Logic Controller (PLC). During software development phases, the design phase should perform an important role to connect between requirements phase and implementation phase as a process of translating problem requirements into software structures. In this work, the Nuclear FBD-style Design Specification and analysis (NuFDS) approach was proposed. The NuFDS approach for nuclear Instrumentation and Control (I and C) software are suggested in a straight forward manner. It consists of four major specifications as follows; Database, Software Architecture, System Behavior, and PLC Hardware Configuration. Additionally, correctness, completeness, consistency, and traceability check techniques are also suggested for the formal design analysis in NuFDS approach. In addition, for the tool supporting, we are developing NuSDS tool based on the NuFDS approach which is a tool, especially for the software design specification in nuclear fields

REVIEW OF NRC APPROVED DIGITAL CONTROL SYSTEMS ANALYSIS

International Nuclear Information System (INIS)

Markman, D.W.

1999-01-01

Preliminary design concepts for the proposed Subsurface Repository at Yucca Mountain indicate extensive reliance on modern, computer-based, digital control technologies. The purpose of this analysis is to investigate the degree to which the U. S. Nuclear Regulatory Commission (NRC) has accepted and approved the use of digital control technology for safety-related applications within the nuclear power industry. This analysis reviews cases of existing digitally-based control systems that have been approved by the NRC. These cases can serve as precedence for using similar types of digitally-based control technologies within the Subsurface Repository. While it is anticipated that the Yucca Mountain Project (YMP) will not contain control systems as complex as those required for a nuclear power plant, the review of these existing NRC approved applications will provide the YMP with valuable insight into the NRCs review process and design expectations for safety-related digital control systems. According to the YMP Compliance Program Guidance, portions of various NUREGS, Regulatory Guidelines, and nuclear IEEE standards the nuclear power plant safety related concept would be applied to some of the designs on a case-by-case basis. This analysis will consider key design methods, capabilities, successes, and important limitations or problems of selected control systems that have been approved for use in the Nuclear Power industry. An additional purpose of this analysis is to provide background information in support of further development of design criteria for the YMP. The scope and primary objectives of this analysis are to: (1) Identify and research the extent and precedence of digital control and remotely operated systems approved by the NRC for the nuclear power industry. Help provide a basis for using and relying on digital technologies for nuclear related safety critical applications. (2) Identify the basic control architecture and methods of key digital control

H∞ Based Control for Load Mitigation in Wind Turbines

Directory of Open Access Journals (Sweden)

Aron Pujana-Arrese

2012-04-01

Full Text Available This article demonstrates a strategy to design multivariable and multi-objective controllers based on the H∞ norm reduction applied to a wind turbine. The wind turbine model has been developed in the GH Bladed software and it is based on a 5 MW wind turbine defined in the Upwind European project. The designed control strategy works in the above rated power production zone and performs generator speed control and load reduction on the drive train and tower. In order to do this, two robust H∞ MISO (Multi-Input Single-Output controllers have been developed. These controllers generate collective pitch angle and generator torque set-point values to achieve the imposed control objectives. Linear models obtained in GH Bladed 4.0 are used, but the control design methodology can be used with linear models obtained from any other modelling package. Controllers are designed by setting out a mixed sensitivity problem, where some notch filters are also included in the controller dynamics. The obtained H∞ controllers have been validated in GH Bladed and an exhaustive analysis has been carried out to calculate fatigue load reduction on wind turbine components, as well as to analyze load mitigation in some extreme cases. The analysis compares the proposed control strategy based on H∞ controllers to a baseline control strategy designed using the classical control methods implemented on the present wind turbines.

Dynamic and Control Analysis of Modular Multi-Parallel Rectifiers (MMR)

DEFF Research Database (Denmark)

Zare, Firuz; Ghosh, Arindam; Davari, Pooya

2017-01-01

This paper presents dynamic analysis of a Modular Multi-Parallel Rectifier (MMR) based on state-space modelling and analysis. The proposed topology is suitable for high power application which can reduce line current harmonics emissions significantly. However, a proper controller is required...... to share and control current through each rectifier. Mathematical analysis and preliminary simulations have been carried out to verify the proposed controller under different operating conditions....

JAX: a micro-computer based X-ray diffractometer controller

International Nuclear Information System (INIS)

Naval, P.C. Jr.

1987-05-01

This paper describes a micro-computer based X-ray diffractometer controller and explores its possibilities in simplifying acquisition and analysis of X-ray powder diffraction data. The interrupt-driven controller can operate in both present time and present count data acquisition modes and allows a data analysis program to execute concurrently with data collection. (Auth.). 16 figs.; 2 tabs

Analysis and control of nonlinear systems. A flatness-based approach

Energy Technology Data Exchange (ETDEWEB)

Levine, Jean [MINES-Paris Tech, 77 - Fontainebleau (France). CAS, Unite Mathematiques et Systemes

2009-07-01

This is the first book on a hot topic in the field of control of nonlinear systems. It ranges from mathematical system theory to practical industrial control applications and addresses two fundamental questions in Systems and Control: how to plan the motion of a system and track the corresponding trajectory in presence of perturbations. It emphasizes on structural aspects and in particular on a class of systems called differentially flat. Part 1 discusses the mathematical theory and part 2 outlines applications of this method in the fields of electric drives (DC motors and linear synchronous motors), magnetic bearings, automotive equipments, cranes, and automatic flight control systems. The author offers web-based videos illustrating some dynamical aspects and case studies in simulation (Scilab and Matlab). (orig.)

Advanced electric drives analysis, control, and modeling using MATLAB/Simulink

CERN Document Server

Mohan, Ned

2014-01-01

Advanced Electric Drives utilizes a physics-based approach to explain the fundamental concepts of modern electric drive control and its operation under dynamic conditions. Gives readers a "physical" picture of electric machines and drives without resorting to mathematical transformations for easy visualization Confirms the physics-based analysis of electric drives mathematically Provides readers with an analysis of electric machines in a way that can be easily interfaced to common power electronic converters and controlled using any control scheme Makes the MATLAB/Simulink files used in exampl

Control-Volume Analysis Of Thrust-Augmenting Ejectors

Science.gov (United States)

Drummond, Colin K.

1990-01-01

New method of analysis of transient flow in thrust-augmenting ejector based on control-volume formulation of governing equations. Considered as potential elements of propulsion subsystems of short-takeoff/vertical-landing airplanes.

Does Self-Control Training Improve Self-Control? A Meta-Analysis.

Science.gov (United States)

Friese, Malte; Frankenbach, Julius; Job, Veronika; Loschelder, David D

2017-11-01

Self-control is positively associated with a host of beneficial outcomes. Therefore, psychological interventions that reliably improve self-control are of great societal value. A prominent idea suggests that training self-control by repeatedly overriding dominant responses should lead to broad improvements in self-control over time. Here, we conducted a random-effects meta-analysis based on robust variance estimation of the published and unpublished literature on self-control training effects. Results based on 33 studies and 158 effect sizes revealed a small-to-medium effect of g = 0.30, confidence interval (CI 95 ) [0.17, 0.42]. Moderator analyses found that training effects tended to be larger for (a) self-control stamina rather than strength, (b) studies with inactive compared to active control groups, (c) males than females, and (d) when proponents of the strength model of self-control were (co)authors of a study. Bias-correction techniques suggested the presence of small-study effects and/or publication bias and arrived at smaller effect size estimates (range: g corrected = .13 to .24). The mechanisms underlying the effect are poorly understood. There is not enough evidence to conclude that the repeated control of dominant responses is the critical element driving training effects.

Comparative performance analysis of the artificial-intelligence-based thermal control algorithms for the double-skin building

International Nuclear Information System (INIS)

Moon, Jin Woo

2015-01-01

This study aimed at developing artificial-intelligence-(AI)-theory-based optimal control algorithms for improving the indoor temperature conditions and heating energy efficiency of the double-skin buildings. For this, one conventional rule-based and four AI-based algorithms were developed, including artificial neural network (ANN), fuzzy logic (FL), and adaptive neuro fuzzy inference systems (ANFIS), for operating the surface openings of the double skin and the heating system. A numerical computer simulation method incorporating the matrix laboratory (MATLAB) and the transient systems simulation (TRNSYS) software was used for the comparative performance tests. The analysis results revealed that advanced thermal-environment comfort and stability can be provided by the AI-based algorithms. In particular, the FL and ANFIS algorithms were superior to the ANN algorithm in terms of providing better thermal conditions. The ANN-based algorithm, however, proved its potential to be the most energy-efficient and stable strategy among the four AI-based algorithms. It can be concluded that the optimal algorithm can be differently determined according to the major focus of the strategy. If comfortable thermal condition is the principal interest, then the FL or ANFIS algorithm could be the proper solution, and if energy saving for space heating and system operation stability is the main concerns, then the ANN-based algorithm may be applicable. - Highlights: • Integrated control algorithms were developed for the heating system and surface openings. • AI theories were applied to the control algorithms. • ANN, FL, and ANFIS were the applied AI theories. • Comparative performance tests were conducted using computer simulation. • AI algorithms presented superior temperature environment.

Qualitative Functional Decomposition Analysis of Evolved Neuromorphic Flight Controllers

Directory of Open Access Journals (Sweden)

Sanjay K. Boddhu

2012-01-01

Full Text Available In the previous work, it was demonstrated that one can effectively employ CTRNN-EH (a neuromorphic variant of EH method methodology to evolve neuromorphic flight controllers for a flapping wing robot. This paper describes a novel frequency grouping-based analysis technique, developed to qualitatively decompose the evolved controllers into explainable functional control blocks. A summary of the previous work related to evolving flight controllers for two categories of the controller types, called autonomous and nonautonomous controllers, is provided, and the applicability of the newly developed decomposition analysis for both controller categories is demonstrated. Further, the paper concludes with appropriate discussion of ongoing work and implications for possible future work related to employing the CTRNN-EH methodology and the decomposition analysis techniques presented in this paper.

Interleukin 1 beta gene and risk of schizophrenia: detailed case-control and family-based studies and an updated meta-analysis.

Science.gov (United States)

Shibuya, Masako; Watanabe, Yuichiro; Nunokawa, Ayako; Egawa, Jun; Kaneko, Naoshi; Igeta, Hirofumi; Someya, Toshiyuki

2014-01-01

Interleukin-1 beta (IL-1β) has been implicated in the pathophysiology of schizophrenia. To assess whether the IL1B gene confers increased susceptibility to schizophrenia, we conducted case-control and family-based studies and an updated meta-analysis. We tested the association between IL1B and schizophrenia in 1229 case-control and 112 trio samples using 12 markers, including common tagging single nucleotide variations (SNVs) and a rare non-synonymous variation detected by resequencing the coding regions. We also performed a meta-analysis of rs16944 using a total of 8724 case-control and 201 trio samples from 16 independent populations. We found no significant associations between any of the 12 SNVs examined and schizophrenia in either case-control or trio samples. Moreover, our meta-analysis results showed no significant association between the common SNV, rs16944, and schizophrenia. The present study does not support a role for IL1B in schizophrenia susceptibility.

A Network of Automatic Control Web-Based Laboratories

Science.gov (United States)

Vargas, Hector; Sanchez Moreno, J.; Jara, Carlos A.; Candelas, F. A.; Torres, Fernando; Dormido, Sebastian

2011-01-01

This article presents an innovative project in the context of remote experimentation applied to control engineering education. Specifically, the authors describe their experience regarding the analysis, design, development, and exploitation of web-based technologies within the scope of automatic control. This work is part of an inter-university…

Benchmarking of industrial control systems via case-based reasoning

International Nuclear Information System (INIS)

Hadjiiski, M.; Boshnakov, K.; Georgiev, Z.

2013-01-01

Full text: The recent development of information and communication technologies enables the establishment of virtual consultation centers related to the control of specific processes that are widely presented worldwide as the location of the installations does not have influence on the results. The centers can provide consultations regarding the quality of the process control and overall enterprise management as correction factors such as weather conditions, product or service and associated technology, production level, quality of feedstock used and others can be also taken into account. The benchmarking technique is chosen as a tool for analyzing and comparing the quality of the assessed control systems in individual plants. It is a process of gathering, analyzing and comparing data on the characteristics of comparable units to assess and compare these characteristics and improve the performance of the particular process, enterprise or organization. By comparing the different processes and the adoption of the best practices energy efficiency could be improved and hence the competitiveness of the participating organizations will increase. In the presented work algorithm for benchmarking and parametric optimization of a given control system is developed by applying the approaches of Case-Based Reasoning (CBR) and Data Envelopment Analysis (DEA). Expert knowledge and approaches for optimal tuning of control systems are combined. Two of the most common systems for automatic control of different variables in the case of biological wastewater treatment are presented and discussed. Based on analysis of the processes, different cases are defined. By using DEA analysis the relative efficiencies of 10 systems for automatic control of dissolved oxygen are estimated. The designed and implemented in the current work CBR and DEA are applicable for the purposed of virtual consultation centers. Key words: benchmarking technique, energy efficiency, Case-Based Reasoning (CBR

Sensitivity Analysis to Control the Far-Wake Unsteadiness Behind Turbines

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Esteban Ferrer

2017-10-01

Full Text Available We explore the stability of wakes arising from 2D flow actuators based on linear momentum actuator disc theory. We use stability and sensitivity analysis (using adjoints to show that the wake stability is controlled by the Reynolds number and the thrust force (or flow resistance applied through the turbine. First, we report that decreasing the thrust force has a comparable stabilising effect to a decrease in Reynolds numbers (based on the turbine diameter. Second, a discrete sensitivity analysis identifies two regions for suitable placement of flow control forcing, one close to the turbines and one far downstream. Third, we show that adding a localised control force, in the regions identified by the sensitivity analysis, stabilises the wake. Particularly, locating the control forcing close to the turbines results in an enhanced stabilisation such that the wake remains steady for significantly higher Reynolds numbers or turbine thrusts. The analysis of the controlled flow fields confirms that modifying the velocity gradient close to the turbine is more efficient to stabilise the wake than controlling the wake far downstream. The analysis is performed for the first flow bifurcation (at low Reynolds numbers which serves as a foundation of the stabilization technique but the control strategy is tested at higher Reynolds numbers in the final section of the paper, showing enhanced stability for a turbulent flow case.

Design of SVC Controller Based on Improved Biogeography-Based Optimization Algorithm

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Feifei Dong

2014-01-01

Full Text Available Considering that common subsynchronous resonance controllers cannot adapt to the characteristics of the time-varying and nonlinear behavior of a power system, the cosine migration model, the improved migration operator, and the mutative scale of chaos and Cauchy mutation strategy are introduced into an improved biogeography-based optimization (IBBO algorithm in order to design an optimal subsynchronous damping controller based on the mechanism of suppressing SSR by static var compensator (SVC. The effectiveness of the improved controller is verified by eigenvalue analysis and electromagnetic simulations. The simulation results of Jinjie plant indicate that the subsynchronous damping controller optimized by the IBBO algorithm can remarkably improve the damping of torsional modes and thus effectively depress SSR, and ensure the safety and stability of units and power grid operation. Moreover, the IBBO algorithm has the merits of a faster searching speed and higher searching accuracy in seeking the optimal control parameters over traditional algorithms, such as BBO algorithm, PSO algorithm, and GA algorithm.

Topological analysis of metabolic control.

Science.gov (United States)

Sen, A K

1990-12-01

A topological approach is presented for the analysis of control and regulation in metabolic pathways. In this approach, the control structure of a metabolic pathway is represented by a weighted directed graph. From an inspection of the topology of the graph, the control coefficients of the enzymes are evaluated in a heuristic manner in terms of the enzyme elasticities. The major advantage of the topological approach is that it provides a visual framework for (1) calculating the control coefficients of the enzymes, (2) analyzing the cause-effect relationships of the individual enzymes, (3) assessing the relative importance of the enzymes in metabolic regulation, and (4) simplifying the structure of a given pathway, from a regulatory viewpoint. Results are obtained for (a) an unbranched pathway in the absence of feedback the feedforward regulation and (b) an unbranched pathway with feedback inhibition. Our formulation is based on the metabolic control theory of Kacser and Burns (1973) and Heinrich and Rapoport (1974).

A rank-based algorithm of differential expression analysis for small cell line data with statistical control.

Science.gov (United States)

Li, Xiangyu; Cai, Hao; Wang, Xianlong; Ao, Lu; Guo, You; He, Jun; Gu, Yunyan; Qi, Lishuang; Guan, Qingzhou; Lin, Xu; Guo, Zheng

2017-10-13

To detect differentially expressed genes (DEGs) in small-scale cell line experiments, usually with only two or three technical replicates for each state, the commonly used statistical methods such as significance analysis of microarrays (SAM), limma and RankProd (RP) lack statistical power, while the fold change method lacks any statistical control. In this study, we demonstrated that the within-sample relative expression orderings (REOs) of gene pairs were highly stable among technical replicates of a cell line but often widely disrupted after certain treatments such like gene knockdown, gene transfection and drug treatment. Based on this finding, we customized the RankComp algorithm, previously designed for individualized differential expression analysis through REO comparison, to identify DEGs with certain statistical control for small-scale cell line data. In both simulated and real data, the new algorithm, named CellComp, exhibited high precision with much higher sensitivity than the original RankComp, SAM, limma and RP methods. Therefore, CellComp provides an efficient tool for analyzing small-scale cell line data. © The Author 2017. Published by Oxford University Press.

Schedulability analysis for systems with data and control dependencies

DEFF Research Database (Denmark)

Pop, Paul; Eles, Petru; Peng, Zebo

2000-01-01

Is this paper we present an approach to schedulability analysis for hard real-time systems with control and data dependencies. We consider distributed architectures consisting of multiple programmable processors, and the scheduling policy is based on a static priority preemptive strategy! Our model...... of the system captures bath data and control dependencies, and the schedulability approach is able to reduce the pessimism of the analysis by using the knowledge about control ann data dependencies. Extensive experiments as well as a real life example demonstrate the efficiency of our approach....

Intelligent Control of Micro Grid: A Big Data-Based Control Center

Science.gov (United States)

Liu, Lu; Wang, Yanping; Liu, Li; Wang, Zhiseng

2018-01-01

In this paper, a structure of micro grid system with big data-based control center is introduced. Energy data from distributed generation, storage and load are analized through the control center, and from the results new trends will be predicted and applied as a feedback to optimize the control. Therefore, each step proceeded in micro grid can be adjusted and orgnized in a form of comprehensive management. A framework of real-time data collection, data processing and data analysis will be proposed by employing big data technology. Consequently, a integrated distributed generation and a optimized energy storage and transmission process can be implemented in the micro grid system.

Control system design and analysis using the INteractive Controls Analysis (INCA) program

Science.gov (United States)

Bauer, Frank H.; Downing, John P.

1987-01-01

The INteractive Controls Analysis (INCA) program was developed at the Goddard Space Flight Center to provide a user friendly efficient environment for the design and analysis of linear control systems. Since its inception, INCA has found extensive use in the design, development, and analysis of control systems for spacecraft, instruments, robotics, and pointing systems. Moreover, the results of the analytic tools imbedded in INCA have been flight proven with at least three currently orbiting spacecraft. This paper describes the INCA program and illustrates, using a flight proven example, how the package can perform complex design analyses with relative ease.

Extremum-Seeking Control and Applications A Numerical Optimization-Based Approach

CERN Document Server

Zhang, Chunlei

2012-01-01

Extremum seeking control tracks a varying maximum or minimum in a performance function such as a cost. It attempts to determine the optimal performance of a control system as it operates, thereby reducing downtime and the need for system analysis. Extremum Seeking Control and Applications is divided into two parts. In the first, the authors review existing analog optimization based extremum seeking control including gradient, perturbation and sliding mode based control designs. They then propose a novel numerical optimization based extremum seeking control based on optimization algorithms and state regulation. This control design is developed for simple linear time-invariant systems and then extended for a class of feedback linearizable nonlinear systems. The two main optimization algorithms – line search and trust region methods – are analyzed for robustness. Finite-time and asymptotic state regulators are put forward for linear and nonlinear systems respectively. Further design flexibility is achieved u...

DESCRIBING FUNCTION METHOD FOR PI-FUZZY CONTROLLED SYSTEMS STABILITY ANALYSIS

Directory of Open Access Journals (Sweden)

Stefan PREITL

2004-12-01

Full Text Available The paper proposes a global stability analysis method dedicated to fuzzy control systems containing Mamdani PI-fuzzy controllers with output integration to control SISO linear / linearized plants. The method is expressed in terms of relatively simple steps, and it is based on: the generalization of the describing function method for the considered fuzzy control systems to the MIMO case, the approximation of the describing functions by applying the least squares method. The method is applied to the stability analysis of a class of PI-fuzzy controlled servo-systems, and validated by considering a case study.

A PSO based unified power flow controller for damping of power system oscillations

Energy Technology Data Exchange (ETDEWEB)

Shayeghi, H. [Technical Engineering Dept., Univ. of Mohaghegh Ardabili, Daneshgah Street, P.O. Box 179, Ardabil (Iran); Shayanfar, H.A. [Center of Excellence for Power Automation and Operation, Electrical Engineering Dept., Iran Univ. of Science and Technology, Tehran (Iran); Jalilzadeh, S.; Safari, A. [Technical Engineering Dept., Zanjan Univ., Zanjan (Iran)

2009-10-15

On the basis of the linearized Phillips-Herffron model of a single-machine power system, we approach the problem of select the best input control signal of the unified power flow controller (UPFC) and design optimal UPFC based damping controller in order to enhance the damping of the power system low frequency oscillations. The potential of the UPFC supplementary controllers to enhance the dynamic stability is evaluated. This controller is tuned to simultaneously shift the undamped electromechanical modes to a prescribed zone in the s-plane. The problem of robustly UPFC based damping controller is formulated as an optimization problem according to the eigenvalue-based multiobjective function comprising the damping factor, and the damping ratio of the undamped electromechanical modes to be solved using particle swarm optimization technique (PSO) that has a strong ability to find the most optimistic results. To ensure the robustness of the proposed damping controller, the design process takes into account a wide range of operating conditions and system configurations. The effectiveness of the proposed controller is demonstrated through eigenvalue analysis, nonlinear time-domain simulation and some performance indices studies. The results analysis reveals that the tuned PSO based UPFC controller using the proposed multiobjective function has an excellent capability in damping power system low frequency oscillations and enhance greatly the dynamic stability of the power systems. Moreover, the system performance analysis under different operating conditions show that the {delta}{sub E} based controller is superior to the m{sub B} based controller. (author)

Design and validation of a morphing myoelectric hand posture controller based on principal component analysis of human grasping.

Science.gov (United States)

Segil, Jacob L; Weir, Richard F ff

2014-03-01

An ideal myoelectric prosthetic hand should have the ability to continuously morph between any posture like an anatomical hand. This paper describes the design and validation of a morphing myoelectric hand controller based on principal component analysis of human grasping. The controller commands continuously morphing hand postures including functional grasps using between two and four surface electromyography (EMG) electrodes pairs. Four unique maps were developed to transform the EMG control signals in the principal component domain. A preliminary validation experiment was performed by 10 nonamputee subjects to determine the map with highest performance. The subjects used the myoelectric controller to morph a virtual hand between functional grasps in a series of randomized trials. The number of joints controlled accurately was evaluated to characterize the performance of each map. Additional metrics were studied including completion rate, time to completion, and path efficiency. The highest performing map controlled over 13 out of 15 joints accurately.

Neural network-based model reference adaptive control system.

Science.gov (United States)

Patino, H D; Liu, D

2000-01-01

In this paper, an approach to model reference adaptive control based on neural networks is proposed and analyzed for a class of first-order continuous-time nonlinear dynamical systems. The controller structure can employ either a radial basis function network or a feedforward neural network to compensate adaptively the nonlinearities in the plant. A stable controller-parameter adjustment mechanism, which is determined using the Lyapunov theory, is constructed using a sigma-modification-type updating law. The evaluation of control error in terms of the neural network learning error is performed. That is, the control error converges asymptotically to a neighborhood of zero, whose size is evaluated and depends on the approximation error of the neural network. In the design and analysis of neural network-based control systems, it is important to take into account the neural network learning error and its influence on the control error of the plant. Simulation results showing the feasibility and performance of the proposed approach are given.

Model dynamic behaviour analysis with chaotic noise using fuzzy logic based control

International Nuclear Information System (INIS)

Silva, Glauco Antonio Santos da

2002-01-01

This work presents an application of fuzzy control on dynamical system models. It has been observed that fuzzy controllers maybe used as a good alternative to the classical PI controller, once it incorporates human line behavior. Three implication relationships were used for the fussy controllers, namely, Mamdani Min, Larsen and Takagi-Sugeno. Performance comparisons were made aiming at achieving the best performance for each model used. The PI controller was used as a minimum standard, once it has been present in the industry for many years, giving acceptable performances and some degree of reliability . Two kinds of perturbations were introduced in the models to test the controllers: a ramp and chaotic perturbations. The first one is a monotonic, standard increase of an input parameter. The second one presents non-periodicity and irregularity in such a way to be quite rough to the controllers. The chaotic signal, as an analysis tool to dynamical systems, is an interesting contribution of this work. As a general conclusion it can be said the best performance, in this work, was achieved by the Takagi-Sugeno fuzzy controller. (author)

Affinity-based biosensors in sport medicine and doping control analysis.

Science.gov (United States)

Mazzei, Franco; Antiochia, Riccarda; Botrè, Francesco; Favero, Gabriele; Tortolini, Cristina

2014-01-01

Affinity-based biosensors (ABBs) have started to be considered in sport medicine and doping control analysis because they are cheap, easy to use and sufficiently selective analytical devices, characterized by a reversible interaction with the analyte under investigation allowing the use of the same sensor for multiple analyses. In this review we describe the main categories of substances reported in the World Anti-Doping Agency Prohibited List and how ABBs may contribute to their detection. Although several ABBs proposed in the last few years display limit of detections that are in principle matching the World Anti-Doping Agency requirements, their application in the framework of 'traditional' antidoping tests seems quite unlikely, mainly because of the still insufficient selectivity especially in the case of 'pseudo-endogenous' compounds, and on the lack of complete information regarding potential matrix effects in real samples and following their routine use. At the same time, ABBs could contribute to fill a significant information gap concerning complementary evidence that can be obtained from their use 'on the spot', as well as to preselect a risk population of individuals to be targeted for a full antidoping test; while in sport medicine they could contribute to obtaining analytical information of physiological relevance from the measurement of specific parameters or markers before, during and after physical exercise.

Updated Meta-Analysis of Learner Control within Educational Technology

Science.gov (United States)

Karich, Abbey C.; Burns, Matthew K.; Maki, Kathrin E.

2014-01-01

Giving a student control over their learning has theoretical and intuitive appeal, but its effects are neither powerful nor consistent in the empirical literature base. This meta-analysis updated previous meta-analytic research by Niemiec, Sikorski, and Walberg by studying the overall effectiveness of providing learner control within educational…

HOTELLING'S T2 CONTROL CHARTS BASED ON ROBUST ESTIMATORS

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SERGIO YÁÑEZ

2010-01-01

Full Text Available Under the presence of multivariate outliers, in a Phase I analysis of historical set of data, the T 2 control chart based on the usual sample mean vector and sample variance covariance matrix performs poorly. Several alternative estimators have been proposed. Among them, estimators based on the minimum volume ellipsoid (MVE and the minimum covariance determinant (MCD are powerful in detecting a reasonable number of outliers. In this paper we propose a T 2 control chart using the biweight S estimators for the location and dispersion parameters when monitoring multivariate individual observations. Simulation studies show that this method outperforms the T 2 control chart based on MVE estimators for a small number of observations.

Simulation on a car interior aerodynamic noise control based on statistical energy analysis

Science.gov (United States)

Chen, Xin; Wang, Dengfeng; Ma, Zhengdong

2012-09-01

How to simulate interior aerodynamic noise accurately is an important question of a car interior noise reduction. The unsteady aerodynamic pressure on body surfaces is proved to be the key effect factor of car interior aerodynamic noise control in high frequency on high speed. In this paper, a detail statistical energy analysis (SEA) model is built. And the vibra-acoustic power inputs are loaded on the model for the valid result of car interior noise analysis. The model is the solid foundation for further optimization on car interior noise control. After the most sensitive subsystems for the power contribution to car interior noise are pointed by SEA comprehensive analysis, the sound pressure level of car interior aerodynamic noise can be reduced by improving their sound and damping characteristics. The further vehicle testing results show that it is available to improve the interior acoustic performance by using detailed SEA model, which comprised by more than 80 subsystems, with the unsteady aerodynamic pressure calculation on body surfaces and the materials improvement of sound/damping properties. It is able to acquire more than 2 dB reduction on the central frequency in the spectrum over 800 Hz. The proposed optimization method can be looked as a reference of car interior aerodynamic noise control by the detail SEA model integrated unsteady computational fluid dynamics (CFD) and sensitivity analysis of acoustic contribution.

WE-G-BRA-06: Application of Systems and Control Theory-Based Hazard Analysis to Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Pawlicki, T [UC San Diego, La Jolla, CA (United States); Samost, A; Leveson, N [Massachusetts Institute of Technology, Cambridge, MA (United States)

2015-06-15

Purpose: The process of delivering radiation occurs in a complex socio-technical system heavily reliant on human operators. Furthermore, both humans and software are notoriously challenging to account for in traditional hazard analysis models. High reliability industries such as aviation have approached this problem through using hazard analysis techniques grounded in systems and control theory. The purpose of this work is to apply the Systems Theoretic Accident Model Processes (STAMP) hazard model to radiotherapy. In particular, the System-Theoretic Process Analysis (STPA) approach is used to perform a hazard analysis of a proposed on-line adaptive cranial radiosurgery procedure that omits the CT Simulation step and uses only CBCT for planning, localization, and treatment. Methods: The STPA procedure first requires the definition of high-level accidents and hazards leading to those accidents. From there, hierarchical control structures were created followed by the identification and description of control actions for each control structure. Utilizing these control structures, unsafe states of each control action were created. Scenarios contributing to unsafe control action states were then identified and translated into system requirements to constrain process behavior within safe boundaries. Results: Ten control structures were created for this new CBCT-only process which covered the areas of hospital and department management, treatment design and delivery, and vendor service. Twenty three control actions were identified that contributed to over 80 unsafe states of those control actions resulting in over 220 failure scenarios. Conclusion: The interaction of people, hardware, and software are highlighted through the STPA approach. STPA provides a hierarchical model for understanding the role of management decisions in impacting system safety so that a process design requirement can be traced back to the hazard and accident that it is intended to mitigate. Varian

Dynamic modeling and controllability analysis of an ethanol reformer for fuel cell application

Energy Technology Data Exchange (ETDEWEB)

Garcia, Vanesa M.; Serra, Maria; Riera, Jordi [Institut de Robotica i Informatica Industrial (CSIC-UPC), Llorens i Artigas 4-6, 08028 Barcelona (Spain); Lopez, Eduardo [Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, ed. ETSEIB, 08028 Barcelona (Spain); Planta Piloto de Ingenieria Quimica (CONICET-UNS), Camino de la Carrindanga km7, 8000 Bahia Blanca (Argentina); Llorca, Jordi [Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, ed. ETSEIB, 08028 Barcelona (Spain)

2010-09-15

This work presents a controllability analysis of a low temperature ethanol reformer based on a cobalt catalyst for fuel cell application. The study is based on a non-linear dynamic model of a reformer which operates in three separate stages: ethanol dehydrogenation to acetaldehyde and hydrogen, acetaldehyde steam reforming, and water-gas-shift reaction. The controllability analysis is focused on the rapid dynamics due to mass balances and is based on a linearization of the complex non-linear model of the reformer. RGA, CN and MRI analysis tools are applied to the linear model suggesting that a good performance can be obtained with decentralized control for frequencies up to 0.1 rad s{sup -1}. (author)

A Calculus for Control Flow Analysis of Security Protocols

DEFF Research Database (Denmark)

Buchholtz, Mikael; Nielson, Hanne Riis; Nielson, Flemming

2004-01-01

The design of a process calculus for anaysing security protocols is governed by three factors: how to express the security protocol in a precise and faithful manner, how to accommodate the variety of attack scenarios, and how to utilise the strengths (and limit the weaknesses) of the underlying...... analysis methodology. We pursue an analysis methodology based on control flow analysis in flow logic style and we have previously shown its ability to analyse a variety of security protocols. This paper develops a calculus, LysaNS that allows for much greater control and clarity in the description...

Analysis and design of hybrid control systems

Energy Technology Data Exchange (ETDEWEB)

Malmborg, J.

1998-05-01

Different aspects of hybrid control systems are treated: analysis, simulation, design and implementation. A systematic methodology using extended Lyapunov theory for design of hybrid systems is developed. The methodology is based on conventional control designs in separate regions together with a switching strategy. Dynamics are not well defined if the control design methods lead to fast mode switching. The dynamics depend on the salient features of the implementation of the mode switches. A theorem for the stability of second order switching together with the resulting dynamics is derived. The dynamics on an intersection of two sliding sets are defined for two relays working on different time scales. The current simulation packages have problems modeling and simulating hybrid systems. It is shown how fast mode switches can be found before or during simulation. The necessary analysis work is a very small overhead for a modern simulation tool. To get some experience from practical problems with hybrid control the switching strategy is implemented in two different software environments. In one of them a time-optimal controller is added to an existing PID controller on a commercial control system. Successful experiments with this hybrid controller shows the practical use of the method 78 refs, 51 figs, 2 tabs

VOCs emission characteristics and priority control analysis based on VOCs emission inventories and ozone formation potentials in Zhoushan

Science.gov (United States)

Wang, Qiaoli; Li, Sujing; Dong, Minli; Li, Wei; Gao, Xiang; Ye, Rongmin; Zhang, Dongxiao

2018-06-01

Zhoushan is an island city with booming tourism and service industry, but also has many developed VOCs and/or NOX emission industries. It is necessary to carry out regional VOCs and O3 pollution control in Zhoushan as the only new area owns the provincial economic and social administration rights. Anthropogenic VOCs emission inventories were built based on emission factor method and main emission sources were identified according to the emission inventories. Then, localized VOCs source profiles were built based on in-site sampling and referring to other studies. Furthermore, ozone formation potentials (OFPs) profiles were built through VOCs source profiles and maximum incremental reactivity (MIR) theory. At last, the priority control analysis results showed that industrial processes, especially surface coating, are the key of VOCs and O3 control. Alkanes were the most emitted group, accounting for 58.67%, while aromatics contributed the most to ozone production accounting for 69.97% in total OFPs. n-butane, m/p-xylene, i-pentane, n-decane, toluene, propane, n-undecane, o-xylene, methyl cyclohexane and ethyl benzene were the top 10 VOC species that should be preferentially controlled for VOCs emission control. However, m/p-xylene, o-xylene, ethylene, n-butane, toluene, propene, 1,2,4-trimethyl benzene, 1,3,5-trimethyl benzene, ethyl benzene and 1,2,3-trimethyl benzene were the top 10 VOC species that required preferential control for O3 pollution control.

Risk-based configuration control

International Nuclear Information System (INIS)

Szikszai, T.

1997-01-01

The presentation discusses the following issues: The Configuration Control; The Risk-based Configuration Control (during power operation mode, and during shutdown mode). PSA requirements. Use of Risk-based Configuration Control System. Configuration Management (basic elements, benefits, information requirements)

LMI-based stability analysis of fuzzy-model-based control systems using approximated polynomial membership functions.

Science.gov (United States)

Narimani, Mohammand; Lam, H K; Dilmaghani, R; Wolfe, Charles

2011-06-01

Relaxed linear-matrix-inequality-based stability conditions for fuzzy-model-based control systems with imperfect premise matching are proposed. First, the derivative of the Lyapunov function, containing the product terms of the fuzzy model and fuzzy controller membership functions, is derived. Then, in the partitioned operating domain of the membership functions, the relations between the state variables and the mentioned product terms are represented by approximated polynomials in each subregion. Next, the stability conditions containing the information of all subsystems and the approximated polynomials are derived. In addition, the concept of the S-procedure is utilized to release the conservativeness caused by considering the whole operating region for approximated polynomials. It is shown that the well-known stability conditions can be special cases of the proposed stability conditions. Simulation examples are given to illustrate the validity of the proposed approach.

Fuzzy logic based control system for fresh water aquaculture: A MATLAB based simulation approach

Directory of Open Access Journals (Sweden)

Rana Dinesh Singh

2015-01-01

Full Text Available Fuzzy control is regarded as the most widely used application of fuzzy logic. Fuzzy logic is an innovative technology to design solutions for multiparameter and non-linear control problems. One of the greatest advantages of fuzzy control is that it uses human experience and process information obtained from operator rather than a mathematical model for the definition of a control strategy. As a result, it often delivers solutions faster than conventional control design techniques. The proposed system is an attempt to apply fuzzy logic techniques to predict the stress factor on the fish, based on line data and rule base generated using domain expert. The proposed work includes a use of Data acquisition system, an interfacing device for on line parameter acquisition and analysis, fuzzy logic controller (FLC for inferring the stress factor. The system takes stress parameters on the fish as inputs, fuzzified by using FLC with knowledge base rules and finally provides single output. All the parameters are controlled and calibrated by the fuzzy logic toolbox and MATLAB programming.

Neural Network-Based Resistance Spot Welding Control and Quality Prediction

Energy Technology Data Exchange (ETDEWEB)

Allen, J.D., Jr.; Ivezic, N.D.; Zacharia, T.

1999-07-10

This paper describes the development and evaluation of neural network-based systems for industrial resistance spot welding process control and weld quality assessment. The developed systems utilize recurrent neural networks for process control and both recurrent networks and static networks for quality prediction. The first section describes a system capable of both welding process control and real-time weld quality assessment, The second describes the development and evaluation of a static neural network-based weld quality assessment system that relied on experimental design to limit the influence of environmental variability. Relevant data analysis methods are also discussed. The weld classifier resulting from the analysis successfldly balances predictive power and simplicity of interpretation. The results presented for both systems demonstrate clearly that neural networks can be employed to address two significant problems common to the resistance spot welding industry, control of the process itself, and non-destructive determination of resulting weld quality.

Control-flow analysis of function calls and returns by abstract interpretation

DEFF Research Database (Denmark)

Midtgaard, Jan; Jensen, Thomas P.

2009-01-01

We derive a control-flow analysis that approximates the interprocedural control-flow of both function calls and returns in the presence of first-class functions and tail-call optimization. In addition to an abstract environment, our analysis computes for each expression an abstract control stack......, effectively approximating where function calls return across optimized tail calls. The analysis is systematically calculated by abstract interpretation of the stack-based CaEK abstract machine of Flanagan et al. using a series of Galois connections. Abstract interpretation provides a unifying setting in which...

Region based Brain Computer Interface for a home control application.

Science.gov (United States)

Akman Aydin, Eda; Bay, Omer Faruk; Guler, Inan

2015-08-01

Environment control is one of the important challenges for disabled people who suffer from neuromuscular diseases. Brain Computer Interface (BCI) provides a communication channel between the human brain and the environment without requiring any muscular activation. The most important expectation for a home control application is high accuracy and reliable control. Region-based paradigm is a stimulus paradigm based on oddball principle and requires selection of a target at two levels. This paper presents an application of region based paradigm for a smart home control application for people with neuromuscular diseases. In this study, a region based stimulus interface containing 49 commands was designed. Five non-disabled subjects were attended to the experiments. Offline analysis results of the experiments yielded 95% accuracy for five flashes. This result showed that region based paradigm can be used to select commands of a smart home control application with high accuracy in the low number of repetitions successfully. Furthermore, a statistically significant difference was not observed between the level accuracies.

Analysis of the relationship between tumor dose inhomogeneity and local control in patients with skull base chordoma

International Nuclear Information System (INIS)

Terahara, Atsuro; Niemierko, Andrzej; Goitein, Michael; Finkelstein, Dianne; Hug, Eugen; Liebsch, Norbert; O'Farrell, Desmond; Lyons, Sue; Munzenrider, John

1999-01-01

Purpose: When irradiating a tumor that abuts or displaces any normal structures, the dose constraints to those structures (if lower than the prescribed dose) may cause dose inhomogeneity in the tumor volume at the tumor-critical structure interface. The low-dose region in the tumor volume may be one of the reasons for local failure. The aim of this study is to quantitate the effect of tumor dose inhomogeneity on local control and recurrence-free survival in patients with skull base chordoma. Methods and Materials: 132 patients with skull base chordoma were treated with combined photon and proton irradiation between 1978 and 1993. This study reviews 115 patients whose dose-volume data and follow-up data are available. The prescribed doses ranged from 66.6 Cobalt-Gray-Equivalent (CGE) to 79.2 CGE (median of 68.9 CGE). The dose to the optic structures (optic nerves and chiasma), the brain stem surface, and the brain stem center was limited to 60, 64, and 53 CGE, respectively. We used the dose-volume histogram data derived with the three-dimensional treatment planning system to evaluate several dose-volume parameters including the Equivalent Uniform Dose (EUD). We also analyzed several other patient and treatment factors in relation to local control and recurrence-free survival. Results: Local failure developed in 42 of 115 patients, with the actuarial local control rates at 5 and 10 years being 59% and 44%. Gender was a significant predictor for local control with the prognosis in males being significantly better than that in females (P 0.004, hazard ratio = 2.3). In a Cox univariate analysis, with stratification by gender, the significant predictors for local control (at the probability level of 0.05) were EUD, the target volume, the minimum dose, and the D 5cc dose. The prescribed dose, histology, age, the maximum dose, the mean dose, the median dose, the D 90% dose, and the overall treatment time were not significant factors. In a Cox multivariate analysis, the

Fuzzy Logic Based Set-Point Weighting Controller Tuning for an Internal Model Control Based PID Controller

Directory of Open Access Journals (Sweden)

Maruthai Suresh

2009-10-01

Full Text Available Controller tuning is the process of adjusting the parameters of the selected controller to achieve optimum response for the controlled process. For many of the control problems, a satisfactory performance is obtained by using PID controllers. One of the main problems with mathematical models of physical systems is that the parameters used in the models cannot be determined with absolute accuracy. The values of the parameters may change with time or various effects. In these cases, conventional controller tuning methods suffer when trying a lot to produce optimum response. In order to overcome these difficulties a fuzzy logic based Set- Point weighting controller tuning method is proposed. The effectiveness of the proposed scheme is analyzed through computer simulation using SIMULINK software and the results are presented. The fuzzy logic based simulation results are compared with Cohen-Coon (CC, Ziegler- Nichols (ZN, Ziegler – Nichols with Set- Point weighting (ZN-SPW, Internal Model Control (IMC and Internal model based PID controller responses (IMC-PID. The effects of process modeling errors and the importance of controller tuning have been brought out using the proposed control scheme.

Shock analysis on hydraulic drive control rod during scram

International Nuclear Information System (INIS)

Song Wei; Qin Benke; Bo Hanliang

2013-01-01

Control rod hydraulic drive mechanism (CRHDM) is a new invention of Institute of Nuclear and New Energy Technology of Tsinghua University. The hydraulic absorber buffers the control rod when it scrams. The control rod fast drop impact experiment was conducted and the key parameters of control rod hydraulic buffering performance were obtained. Based on the test results and according to D'Alembert principle, the maximum inertial impact force on the control rod during the fast drop period was applied as equivalent static load force on the control rod. The deformations and stress distributions on the control rod in this worst case were calculated by using finite element software ABAQUS. Calculation results were compared with the experiment results, and it was verified that nonlinear transient dynamics analysis in this problem can be simplified as static analysis. Damage criterion of the control rod fast drop impact process was also given. And it lays foundation for optimal design of the control rod and hydraulic absorber. (authors)

Control-flow analysis of function calls and returns by abstract interpretation

DEFF Research Database (Denmark)

Midtgaard, Jan; Jensen, Thomas P.

2012-01-01

Abstract interpretation techniques are used to derive a control-flow analysis for a simple higher-order functional language. The analysis approximates the interprocedural control-flow of both function calls and returns in the presence of first-class functions and tail-call optimization. In additi...... a rational reconstruction of a constraint-based CFA from abstract interpretation principles....

Control of Greenhouse Environmental Conditions with IOT Based Monitoring and Analysis System

Directory of Open Access Journals (Sweden)

Ali Çaylı

2017-10-01

Full Text Available Wireless sensor networks applications and inter-machine communication (M2M, called the Internet of Things, help decision-makers to control complex systems thanks to the low data-rate and cost-effective data collection and analysis. These technologies offer new possibilities to monitor environmental management and agricultural policies, and to improve agricultural production, especially in low-income rural areas. In this study, IoT is proposed with a low cost, flexible and scalable data collection and analysis system. For this purpose, open source hardware microprocessor cards and sensors are stored in the greenhouse computer database using the IEEE 802.15.4 Zigbee wireless communication protocol. The data can be analyzed by greenhouse computer analysis software, which is developed with the PHP programming language. It is possible to monitor the real time data from the greenhouse computer. Also alert rules definitions can be made and the system was tested in greenhouse conditions. It has been observed that it performs operations steadily such as data transfer, sensor measurements and data processing. The proposed system may be useful for monitoring indoor climate and controlling ventilation, irrigation and heating systems, especially for small enterprises due to the modular structure.

Nonlinear analysis and control of a continuous fermentation process

DEFF Research Database (Denmark)

Szederkényi, G.; Kristensen, Niels Rode; Hangos, K.M

2002-01-01

Different types of nonlinear controllers are designed and compared for a simple continuous bioreactor operating near optimal productivity. This operating point is located close to a fold bifurcation point. Nonlinear analysis of stability, controllability and zero dynamics is used to investigate o...... are recommended for the simple fermenter. Passivity based controllers have been found to be globally stable, not very sensitive to the uncertainties in the reaction rate and controller parameter but they require full nonlinear state feedback....

Model-based expert systems for linac computer controls

International Nuclear Information System (INIS)

Lee, M.J.

1988-09-01

The use of machine modeling and beam simulation programs for the control of accelerator operation has become standard practice. The success of a model-based control operation depends on how the parameter to be controlled is measured, how the measured data is analyzed, how the result of the analysis is interpreted, and how a solution is implemented. There is considerable interest in applying expert systems technology that can automate all of these processes. The design of an expert system to control the beam trajectory in linear accelerators will be discussed as an illustration of this approach. 4 figs., 1 tab

Microbiological performance of Hazard Analysis Critical Control Point (HACCP)-based food safety management systems: A case of Nile perch processing company

NARCIS (Netherlands)

Kussaga, J.B.; Luning, P.A.; Tiisekwa, B.P.M.; Jacxsens, L.

2017-01-01

This study aimed at giving insight into microbiological safety output of a Hazard Analysis Critical Control Point (HACCP)-based Food Safety Management System (FSMS) of a Nile perch exporting company by using a combined assessment, This study aimed at giving insight into microbiological safety output

State Analysis: A Control Architecture View of Systems Engineering

Science.gov (United States)

Rasmussen, Robert D.

2005-01-01

A viewgraph presentation on the state analysis process is shown. The topics include: 1) Issues with growing complexity; 2) Limits of common practice; 3) Exploiting a control point of view; 4) A glimpse at the State Analysis process; 5) Synergy with model-based systems engineering; and 6) Bridging the systems to software gap.

Harmonic Analysis on Torque Ripple of Brushless DC Motor Based on Advanced Commutation Control

Directory of Open Access Journals (Sweden)

Yanpeng Ji

2018-01-01

Full Text Available This paper investigates the relationship between current, back electromotive force (back-EMF, and torque for permanent-magnet brushless DC (PM BLDC motors under advanced commutation control from the perspective of harmonics. Considering that the phase current is the influencing factor of both torque and torque ripple, this paper firstly analyzes the effects of advanced commutation on phase current and current harmonics. And then, based on the harmonics of the phase current and back-EMF, the torque harmonic expressions are deduced. The expressions reveal the relationship of harmonic order between the torque, phase current, and back-EMF and highlight the different contribution of individual torque harmonic to the total torque ripple. Finally, the proposed harmonic analysis method is verified by the experiments with different speed and load conditions.

Convergence Analysis of Distributed Control for Operation Cost Minimization of Droop Controlled DC Microgrid Based on Multiagent

DEFF Research Database (Denmark)

Li, Chendan; Quintero, Juan Carlos Vasquez; Guerrero, Josep M.

2016-01-01

In this paper we present a distributed control method for minimizing the operation cost in DC microgrid based on multiagent system. Each agent is autonomous and controls the local converter in a hierarchical way through droop control, voltage scheduling and collective decision making....... The collective decision for the whole system is made by proposed incremental cost consensus, and only nearest-neighbor communication is needed. The convergence characteristics of the consensus algorithm are analyzed considering different communication topologies and control parameters. Case studies verified...... the proposed method by comparing it without traditional methods. The robustness of system is tested under different communication latency and plug and play operation....

Modeling and Grid impedance Variation Analysis of Parallel Connected Grid Connected Inverter based on Impedance Based Harmonic Analysis

DEFF Research Database (Denmark)

Kwon, JunBum; Wang, Xiongfei; Bak, Claus Leth

2014-01-01

This paper addresses the harmonic compensation error problem existing with parallel connected inverter in the same grid interface conditions by means of impedance-based analysis and modeling. Unlike the single grid connected inverter, it is found that multiple parallel connected inverters and grid...... impedance can make influence to each other if they each have a harmonic compensation function. The analysis method proposed in this paper is based on the relationship between the overall output impedance and input impedance of parallel connected inverter, where controller gain design method, which can...

An Extended Role Based Access Control Method for XML Documents

Institute of Scientific and Technical Information of China (English)

MENG Xiao-feng; LUO Dao-feng; OU Jian-bo

2004-01-01

As XML has been increasingly important as the Data-change format of Internet and Intranet, access-control-on-XML-properties rises as a new issue.Role-based access control (RBAC) is an access control method that has been widely used in Internet, Operation System and Relation Data Base these 10 years.Though RBAC is already relatively mature in the above fields, new problems occur when it is used in XML properties.This paper proposes an integrated model to resolve these problems, after the fully analysis on the features of XML and RBAC.

Backstepping Based Formation Control of Quadrotors with the State Transformation Technique

Directory of Open Access Journals (Sweden)

Keun Uk Lee

2017-11-01

Full Text Available In this paper, a backstepping-based formation control of quadrotors with the state transformation technique is proposed. First, the dynamics of a quadrotor is derived by using the Newton–Euler formulation. Next, a backstepping-based formation control for quadrotors using a state transformation technique is presented. In the position control, which is the basis of formation control, it is possible to derive the reference attitude angles employing a state transformation technique without the small angle assumption or the simplified dynamics usually used. Stability analysis based on the Lyapunov theorem shows that the proposed formation controller can provide a quadrotor formation error system that is asymptotically stabilized. Finally, we verify the performance of the proposed formation control method through comparison simulations.

Web-Based Analysis for Decision Support Systems

African Journals Online (AJOL)

pc

2018-03-05

Mar 5, 2018 ... Faculty of Computing and Information Technology, King Abdulaziz University, Jeddah, SA ... impact of web-based analysis on DSSs and how it affects ... Internal users. ... and control of models, especially accounting, financial,.

Does perturbation-based balance training prevent falls? Systematic review and meta-analysis of preliminary randomized controlled trials.

Science.gov (United States)

Mansfield, Avril; Wong, Jennifer S; Bryce, Jessica; Knorr, Svetlana; Patterson, Kara K

2015-05-01

Older adults and individuals with neurological conditions are at an increased risk for falls. Although physical exercise can prevent falls, certain types of exercise may be more effective. Perturbation-based balance training is a novel intervention involving repeated postural perturbations aiming to improve control of rapid balance reactions. The purpose of this study was to estimate the effect of perturbation-based balance training on falls in daily life. MEDLINE (1946-July 2014), EMBASE (1974-July 2014), PEDro (all dates), CENTRAL (1991-July 2014), and Google Scholar (all dates) were the data sources used in this study. Randomized controlled trials written in English were included if they focused on perturbation-based balance training among older adults or individuals with neurological conditions and collected falls data posttraining. Two investigators extracted data independently. Study authors were contacted to obtain missing information. A PEDro score was obtained for each study. Primary outcomes were proportion of participants who reported one or more falls (ie, number of "fallers") and the total number of falls. The risk ratio (proportion of fallers) and rate ratio (number of falls) were entered into the analysis. Eight studies involving 404 participants were included. Participants who completed perturbation-based balance training were less likely to report a fall (overall risk ratio=0.71; 95% confidence interval=0.52, 0.96; P=.02) and reported fewer falls than those in the control groups (overall rate ratio=0.54; 95% confidence interval=0.34, 0.85; P=.007). Study authors do not always identify that they have included perturbation training in their intervention; therefore, it is possible that some appropriate studies were not included. Study designs were heterogeneous, preventing subanalyses. Perturbation-based balance training appears to reduce fall risk among older adults and individuals with Parkinson disease. © 2015 American Physical Therapy Association.

Applied Research of Enterprise Cost Control Based on Linear Programming

Directory of Open Access Journals (Sweden)

Yu Shuo

2015-01-01

This paper researches the enterprise cost control through the linear programming model, and analyzes the restriction factors of the labor of enterprise production, raw materials, processing equipment, sales price, and other factors affecting the enterprise income, so as to obtain an enterprise cost control model based on the linear programming. This model can calculate rational production mode in the case of limited resources, and acquire optimal enterprise income. The production guiding program and scheduling arrangement of the enterprise can be obtained through calculation results, so as to provide scientific and effective guidance for the enterprise production. This paper adds the sensitivity analysis in the linear programming model, so as to learn about the stability of the enterprise cost control model based on linear programming through the sensitivity analysis, and verify the rationality of the model, and indicate the direction for the enterprise cost control. The calculation results of the model can provide a certain reference for the enterprise planning in the market economy environment, which have strong reference and practical significance in terms of the enterprise cost control.

Contamination control - the analysis of things as they should be

International Nuclear Information System (INIS)

Stewart, R.B.

Contamination can be controlled in chemical analyses by the use of suitable containers, cleanliness, appropriate apparatus design, isolation of the analysis process from air, and in-situ analysis. Examples based on analyses of organic reactor coolant, metals, and underground natural waters are given. (LL)

Multiagent System-Based Wide-Area Protection and Control Scheme against Cascading Events

DEFF Research Database (Denmark)

Liu, Zhou; Chen, Zhe; Sun, Haishun

2015-01-01

In this paper, a multi agent system (MAS) based wide area protection and control scheme is proposed to deal with the long term voltage instability induced cascading trips. Based on sensitivity analysis between the relay operation margin and power system state variables, an optimal emergency control...... strategy is defined to adjust the emergency states timely and prevent the unexpected relay trips. In order to supervise the control process and further minimize the load loss, an agent based process control is adopted to monitor the states of distributed controllers and adjust the emergency control...... strategy. A hybrid simulation platform based on LabVIEW and real time digital simulator (RTDS) is set up to simulate a blackout case in the power system of Eastern Denmark and to demonstrate the effectiveness of the proposed MAS based protection strategy....

Integrated analysis tools for trade studies of spacecraft controller and sensor locations

Science.gov (United States)

Rowell, L. F.

1986-01-01

The present investigation was conducted with the aim to evaluate the practicality and difficulties of modern control design methods for large space structure controls. The evaluation is used as a basis for the identification of useful computer-based analysis tools which would provide insight into control characteristics of a spacecraft concept. A description is presented of the wrap-rib antenna and its packaging concept. Attention is given to active control requirements, a mathematical model of structural dynamics, aspects of sensor and actuator location, the analysis approach, controllability, observability, the concept of balanced realization, transmission zeros, singular value plots, analysis results, model reduction, and an interactive computer program. It is pointed out that the application of selected control analysis tools to the wrap-rib antenna demonstrates several capabilities which can be useful during conceptual design.

Robustness and Actuator Bandwidth of MRP-Based Sliding Mode Control for Spacecraft Attitude Control Problems

Science.gov (United States)

Keum, Jung-Hoon; Ra, Sung-Woong

2009-12-01

Nonlinear sliding surface design in variable structure systems for spacecraft attitude control problems is studied. A robustness analysis is performed for regular form of system, and calculation of actuator bandwidth is presented by reviewing sliding surface dynamics. To achieve non-singular attitude description and minimal parameterization, spacecraft attitude control problems are considered based on modified Rodrigues parameters (MRP). It is shown that the derived controller ensures the sliding motion in pre-determined region irrespective of unmodeled effects and disturbances.

Impedance-based Analysis of DC Link Control in Voltage Source Rectifiers

DEFF Research Database (Denmark)

Lu, Dapeng; Wang, Xiongfei; Blaabjerg, Frede

2018-01-01

This paper analyzes the dynamics influences of the outer dc link control in the voltage source rectifiers based on the impedance model. The ac-dc interactions are firstly presented by means of full order small signal model in dq frame, which shows the input voltage and load condition are the two...

Analysis of maizena drying system using temperature control based fuzzy logic method

Science.gov (United States)

Arief, Ulfah Mediaty; Nugroho, Fajar; Purbawanto, Sugeng; Setyaningsih, Dyah Nurani; Suryono

2018-03-01

Corn is one of the rice subtitution food that has good potential. Corn can be processed to be a maizena, and it can be used to make type of food that has been made from maizena, viz. Brownies cake, egg roll, and other cookies. Generally, maizena obtained by drying process carried out 2-3 days under the sun. However, drying process not possible during the rainy season. This drying process can be done using an automatic drying tool. This study was to analyze the design result and manufacture of maizena drying system with temperature control based fuzzylogic method. The result show that temperature of drying system with set point 40°C - 60°C work in suitable condition. The level of water content in 15% (BSN) and temperatureat 50°C included in good drying process. Time required to reach the set point of temperature in 50°C is 7.05 minutes. Drying time for 500 gr samples with temperature 50°C and power capacity 127.6 watt was 1 hour. Based on the result, drying process using temperature control based fuzzy logic method can improve energy efficiency than the conventional method of drying using a direct sunlight source with a temperature that cannot be directly controlled by human being causing the quality of drying result of flour is erratic.

Rudder Based Roll Control via host-computer of A Robotic Boat

OpenAIRE

Bao, Xinping; Yu, Zhenyu; Nonami, Kenzo

2009-01-01

Rudder based roll control of a small-sized robotic boat is a key technique for the devices on board to achieve good performance. This paper introduces a host-based robotic boat capable of performing basic movement operations. The course keeping and roll reduction are studied via rudder based method in simulations and sea trials. The boat dynamic model is built with the combination of mathematical analysis and system identification technique. A mixed sensitivity H control method design is sele...

A LabVIEW®-based software for the control of the AUTORAD platform. A fully automated multisequential flow injection analysis Lab-on-Valve (MSFIA-LOV) system for radiochemical analysis

International Nuclear Information System (INIS)

Barbesi, Donato; Vilas, Victor Vicente; Millet, Sylvain; Sandow, Miguel; Colle, Jean-Yves; Heras, Laura Aldave de las

2017-01-01

A LabVIEW®-based software for the control of the fully automated multi-sequential flow injection analysis Lab-on-Valve (MSFIA-LOV) platform AutoRAD performing radiochemical analysis is described. The analytical platform interfaces an Arduino®-based device triggering multiple detectors providing a flexible and fit for purpose choice of detection systems. The different analytical devices are interfaced to the PC running LabVIEW®VI software using USB and RS232 interfaces, both for sending commands and receiving confirmation or error responses. The AUTORAD platform has been successfully applied for the chemical separation and determination of Sr, an important fission product pertinent to nuclear waste. (author)

A LabVIEW®-based software for the control of the AUTORAD platform: a fully automated multisequential flow injection analysis Lab-on-Valve (MSFIA-LOV) system for radiochemical analysis.

Science.gov (United States)

Barbesi, Donato; Vicente Vilas, Víctor; Millet, Sylvain; Sandow, Miguel; Colle, Jean-Yves; Aldave de Las Heras, Laura

2017-01-01

A LabVIEW ® -based software for the control of the fully automated multi-sequential flow injection analysis Lab-on-Valve (MSFIA-LOV) platform AutoRAD performing radiochemical analysis is described. The analytical platform interfaces an Arduino ® -based device triggering multiple detectors providing a flexible and fit for purpose choice of detection systems. The different analytical devices are interfaced to the PC running LabVIEW ® VI software using USB and RS232 interfaces, both for sending commands and receiving confirmation or error responses. The AUTORAD platform has been successfully applied for the chemical separation and determination of Sr, an important fission product pertinent to nuclear waste.

Distributed model based control of multi unit evaporation systems

International Nuclear Information System (INIS)

Yudi Samyudia

2006-01-01

In this paper, we present a new approach to the analysis and design of distributed control systems for multi-unit plants. The approach is established after treating the effect of recycled dynamics as a gap metric uncertainty from which a distributed controller can be designed sequentially for each unit to tackle the uncertainty. We then use a single effect multi-unit evaporation system to illustrate how the proposed method is used to analyze different control strategies and to systematically achieve a better closed-loop performance using a distributed model-based controller

Pixel extraction based integral imaging with controllable viewing direction

International Nuclear Information System (INIS)

Ji, Chao-Chao; Deng, Huan; Wang, Qiong-Hua

2012-01-01

We propose pixel extraction based integral imaging with a controllable viewing direction. The proposed integral imaging can provide viewers three-dimensional (3D) images in a very small viewing angle. The viewing angle and the viewing direction of the reconstructed 3D images are controlled by the pixels extracted from an elemental image array. Theoretical analysis and a 3D display experiment of the viewing direction controllable integral imaging are carried out. The experimental results verify the correctness of the theory. A 3D display based on the integral imaging can protect the viewer’s privacy and has huge potential for a television to show multiple 3D programs at the same time. (paper)

HuRECA: Human Reliability Evaluator for Computer-based Control Room Actions

International Nuclear Information System (INIS)

Kim, Jae Whan; Lee, Seung Jun; Jang, Seung Cheol

2011-01-01

As computer-based design features such as computer-based procedures (CBP), soft controls (SCs), and integrated information systems are being adopted in main control rooms (MCR) of nuclear power plants, a human reliability analysis (HRA) method capable of dealing with the effects of these design features on human reliability is needed. From the observations of human factors engineering verification and validation experiments, we have drawn some major important characteristics on operator behaviors and design-related influencing factors (DIFs) from the perspective of human reliability. Firstly, there are new DIFs that should be considered in developing an HRA method for computer-based control rooms including especially CBP and SCs. In the case of the computer-based procedure rather than the paper-based procedure, the structural and managerial elements should be considered as important PSFs in addition to the procedural contents. In the case of the soft controllers, the so-called interface management tasks (or secondary tasks) should be reflected in the assessment of human error probability. Secondly, computer-based control rooms can provide more effective error recovery features than conventional control rooms. Major error recovery features for computer-based control rooms include the automatic logic checking function of the computer-based procedure and the information sharing feature of the general computer-based designs

Development of a novel disturbance observer based fractional order PD controller for a gun control system.

Science.gov (United States)

Gao, Qiang; Zheng, Liang; Chen, Jilin; Wang, Li; Hou, Yuanlong

2014-01-01

Motion control of gun barrels is an ongoing topic for the development of gun control equipment (GCE) with excellent performances. In this paper, a novel disturbance observer (DOB) based fractional order PD (FOPD) control strategy is proposed for the GCE. By adopting the DOB, the control system behaves as if it were the nominal closed-loop system in the absence of disturbances and uncertainties. The optimal control parameters of the FOPD are determined from the loop-shaping perspective, and the Q-filter of the DOB is deliberately designed with consideration of system robustness. The linear frame of the proposed control system will enable the analysis process more convenient. The disturbance rejection properties and the tracking performances of the control system are investigated by both numerical and experimental tests, the results demonstrate that the proposed DOB based FOPD control system is of more robustness, and it is much more suitable for the gun control system with strong nonlinearity and disturbance.

Broadband network on-line data acquisition system with web based interface for control and basic analysis

Science.gov (United States)

Polkowski, Marcin; Grad, Marek

2016-04-01

Passive seismic experiment "13BB Star" is operated since mid 2013 in northern Poland and consists of 13 broadband seismic stations. One of the elements of this experiment is dedicated on-line data acquisition system comprised of both client (station) side and server side modules with web based interface that allows monitoring of network status and provides tools for preliminary data analysis. Station side is controlled by ARM Linux board that is programmed to maintain 3G/EDGE internet connection, receive data from digitizer, send data do central server among with additional auxiliary parameters like temperatures, voltages and electric current measurements. Station side is controlled by set of easy to install PHP scripts. Data is transmitted securely over SSH protocol to central server. Central server is a dedicated Linux based machine. Its duty is receiving and processing all data from all stations including auxiliary parameters. Server side software is written in PHP and Python. Additionally, it allows remote station configuration and provides web based interface for user friendly interaction. All collected data can be displayed for each day and station. It also allows manual creation of event oriented plots with different filtering abilities and provides numerous status and statistic information. Our solution is very flexible and easy to modify. In this presentation we would like to share our solution and experience. National Science Centre Poland provided financial support for this work via NCN grant DEC-2011/02/A/ST10/00284.

Evaluation of Arm Processor-based Bionic Intelligent Controller for a Buck-boost Converte

OpenAIRE

M.V. Mini; L. Padma Suresh

2015-01-01

This study focuses on performance-comparison of different tuning methods for a PI controller applied to a buck-boost converter. Comparison between the controllers is made by analysis of design methodology implementation issues and empirically measured performance. Design of PI controller is based on frequency response of the converter. The optimization of PI controller is based on ant colony algorithm. Experimental results show that, tuning the PI controller using ACO algorithm gave better pe...

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...

Digital Resonant Controller based on Modified Tustin Discretization Method

Directory of Open Access Journals (Sweden)

STOJIC, D.

2016-11-01

Full Text Available Resonant controllers are used in power converter voltage and current control due to their simplicity and accuracy. However, digital implementation of resonant controllers introduces problems related to zero and pole mapping from the continuous to the discrete time domain. Namely, some discretization methods introduce significant errors in the digital controller resonant frequency, resulting in the loss of the asymptotic AC reference tracking, especially at high resonant frequencies. The delay compensation typical for resonant controllers can also be compromised. Based on the existing analysis, it can be concluded that the Tustin discretization with frequency prewarping represents a preferable choice from the point of view of the resonant frequency accuracy. However, this discretization method has a shortcoming in applications that require real-time frequency adaptation, since complex trigonometric evaluation is required for each frequency change. In order to overcome this problem, in this paper the modified Tustin discretization method is proposed based on the Taylor series approximation of the frequency prewarping function. By comparing the novel discretization method with commonly used two-integrator-based proportional-resonant (PR digital controllers, it is shown that the resulting digital controller resonant frequency and time delay compensation errors are significantly reduced for the novel controller.

Plug-in Based Analysis Framework for LHC Post-Mortem Analysis

CERN Document Server

Gorbonosov, R; Zerlauth, M; Baggiolini, V

2014-01-01

Plug-in based software architectures [1] are extensible, enforce modularity and allow several teams to work in parallel. But they have certain technical and organizational challenges, which we discuss in this paper. We gained our experience when developing the Post-Mortem Analysis (PMA) system, which is a mission critical system for the Large Hadron Collider (LHC). We used a plugin-based architecture with a general-purpose analysis engine, for which physicists and equipment experts code plugins containing the analysis algorithms. We have over 45 analysis plugins developed by a dozen of domain experts. This paper focuses on the design challenges we faced in order to mitigate the risks of executing third-party code: assurance that even a badly written plugin doesn't perturb the work of the overall application; plugin execution control which allows to detect plugin misbehaviour and react; robust communication mechanism between plugins, diagnostics facilitation in case of plugin failure; testing of the plugins be...

COA based robust output feedback UPFC controller design

Energy Technology Data Exchange (ETDEWEB)

Shayeghi, H., E-mail: hshayeghi@gmail.co [Technical Engineering Department, University of Mohaghegh Ardabili, Ardabil (Iran, Islamic Republic of); Shayanfar, H.A. [Center of Excellence for Power System Automation and Operation, Electrical Engineering Department, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Jalilzadeh, S.; Safari, A. [Technical Engineering Department, Zanjan University, Zanjan (Iran, Islamic Republic of)

2010-12-15

In this paper, a novel method for the design of output feedback controller for unified power flow controller (UPFC) using chaotic optimization algorithm (COA) is developed. Chaotic optimization algorithms, which have the features of easy implementation, short execution time and robust mechanisms of escaping from the local optimum, is a promising tool for the engineering applications. The selection of the output feedback gains for the UPFC controllers is converted to an optimization problem with the time domain-based objective function which is solved by a COA based on Lozi map. Since chaotic mapping enjoys certainty, ergodicity and the stochastic property, the proposed chaotic optimization problem introduces chaos mapping using Lozi map chaotic sequences which increases its convergence rate and resulting precision. To ensure the robustness of the proposed stabilizers, the design process takes into account a wide range of operating conditions and system configurations. The effectiveness of the proposed controller for damping low frequency oscillations is tested and demonstrated through non-linear time-domain simulation and some performance indices studies. The results analysis reveals that the designed COA based output feedback UPFC damping controller has an excellent capability in damping power system low frequency oscillations and enhance greatly the dynamic stability of the power systems.

Seismic qualification of nuclear control board by using base isolation technique

International Nuclear Information System (INIS)

Koizumi, T.; Tsujiuchi, N.; Fujita, T.

1987-01-01

The purpose is to adopt base isolation technique as a new approach for seismic qualification of nuclear control board. Basic concept of base isolation technique is expressed. Two dimensional linear motion mechanism with pre-tensioned coil springs and some dampers are included in the isolation device. Control board is regarded as a lamped mass system with inertia moment. Fundamental movement of this device and control board is calculated as a non-linear response problems. Fundamental analysis and numerical estimation, experimental investigation has been undertaken using an actual size control board. Sufficient agreement was recognized between experimental results and numerical estimation. (orig./HP)

Human factor analysis related to new symptom based procedures used by control room crews during treatment of emergency states

International Nuclear Information System (INIS)

Holy, J.

1999-01-01

New symptom based emergency procedures have been developed for Nuclear Power Plant Dukovany in the Czech Republic. As one point of the process of verification and validation of the procedures, a specific effort was devoted to detailed analysis of the procedures from human factors and human reliability point of view. The course and results of the analysis are discussed in this article. Although the analyzed procedures have been developed for one specific plant of WWER-440/213 type, most of the presented results may be valid for many other procedures recently developed for semi-automatic control of those technological units which are operated under measurable level of risk. (author)

Optical polarimeter based on Fourier analysis and electronic control

International Nuclear Information System (INIS)

Vilardy, J; Salas, V.; Torres, C.

2016-01-01

In this paper, we show the design and implementation of an optical polarimeter using electronic control and the Fourier analysis. The polarimeter prototype will be used as a main tool for the students of the Universidad Popular del Cesar that belong to the following university programs: Electronics engineering (optoelectronics area), Math and Physics degree and the Master in Physics Sciences, in order to learning the theory and experimental aspects of the state of optical polarization via the Stokes vector measurement. Using the electronic polarimeter proposed in this paper, the students will be able to observe (in an optical bench) and understand the different interactions of the states of optical polarization when the optical waves pass through to the polarizers and retarder waves plates. The electronic polarimeter has a software that captures the optical intensity measurement and evaluates the Stokes vector. (Author)

Robust hopping based on virtual pendulum posture control

International Nuclear Information System (INIS)

Sharbafi, Maziar A; Ahmadabadi, Majid Nili; Yazdanpanah, Mohammad J; Maufroy, Christophe; Seyfarth, Andre

2013-01-01

A new control approach to achieve robust hopping against perturbations in the sagittal plane is presented in this paper. In perturbed hopping, vertical body alignment has a significant role for stability. Our approach is based on the virtual pendulum concept, recently proposed, based on experimental findings in human and animal locomotion. In this concept, the ground reaction forces are pointed to a virtual support point, named virtual pivot point (VPP), during motion. This concept is employed in designing the controller to balance the trunk during the stance phase. New strategies for leg angle and length adjustment besides the virtual pendulum posture control are proposed as a unified controller. This method is investigated by applying it on an extension of the spring loaded inverted pendulum (SLIP) model. Trunk, leg mass and damping are added to the SLIP model in order to make the model more realistic. The stability is analyzed by Poincaré map analysis. With fixed VPP position, stability, disturbance rejection and moderate robustness are achieved, but with a low convergence speed. To improve the performance and attain higher robustness, an event-based control of the VPP position is introduced, using feedback of the system states at apexes. Discrete linear quartic regulator is used to design the feedback controller. Considerable enhancements with respect to stability, convergence speed and robustness against perturbations and parameter changes are achieved. (paper)

Simulation and analysis of main steam control system based on heat transfer calculation

Science.gov (United States)

Huang, Zhenqun; Li, Ruyan; Feng, Zhongbao; Wang, Songhan; Li, Wenbo; Cheng, Jiwei; Jin, Yingai

2018-05-01

In this paper, after thermal power plant 300MW boiler was studied, mat lab was used to write calculation program about heat transfer process between the main steam and boiler flue gas and amount of water was calculated to ensure the main steam temperature keeping in target temperature. Then heat transfer calculation program was introduced into Simulink simulation platform based on control system multiple models switching and heat transfer calculation. The results show that multiple models switching control system based on heat transfer calculation not only overcome the large inertia of main stream temperature, a large hysteresis characteristic of main stream temperature, but also adapted to the boiler load changing.

Control of modular multilevel converters based on time-scale analysis and orthogonal functions

DEFF Research Database (Denmark)

Zarri, L.; Tani, A.; Mengoni, M.

2014-01-01

current is still a complex task and cannot be fully tackled with traditional linear control techniques. In this paper a multiple time-scale analysis is proposed to determine an approximated model of the MMC that can be used to solve the control problem of the capacitor voltages. In addition, it is shown...... that the reference signal of the circulating current can be built by combining orthogonal functions of the measured voltages and currents. Numerical simulations are used to test the feasibility of the developed approach.......Modular multilevel converter (MMC) is a promising multilevel topology for high-voltage applications that has been developed in recent years. The control of MMCs has been analyzed in detail in many papers, showing that the converter capacitors can be kept charged and balanced by controlling...

Elements for successful sensor-based process control {Integrated Metrology}

International Nuclear Information System (INIS)

Butler, Stephanie Watts

1998-01-01

Current productivity needs have stimulated development of alternative metrology, control, and equipment maintenance methods. Specifically, sensor applications provide the opportunity to increase productivity, tighten control, reduce scrap, and improve maintenance schedules and procedures. Past experience indicates a complete integrated solution must be provided for sensor-based control to be used successfully in production. In this paper, Integrated Metrology is proposed as the term for an integrated solution that will result in a successful application of sensors for process control. This paper defines and explores the perceived four elements of successful sensor applications: business needs, integration, components, and form. Based upon analysis of existing successful commercially available controllers, the necessary business factors have been determined to be strong, measurable industry-wide business needs whose solution is profitable and feasible. This paper examines why the key aspect of integration is the decision making process. A detailed discussion is provided of the components of most importance to sensor based control: decision-making methods, the 3R's of sensors, and connectivity. A metric for one of the R's (resolution) is proposed to allow focus on this important aspect of measurement. A form for these integrated components which synergistically partitions various aspects of control at the equipment and MES levels to efficiently achieve desired benefits is recommended

Elements for successful sensor-based process control {Integrated Metrology}

Science.gov (United States)

Butler, Stephanie Watts

1998-11-01

Current productivity needs have stimulated development of alternative metrology, control, and equipment maintenance methods. Specifically, sensor applications provide the opportunity to increase productivity, tighten control, reduce scrap, and improve maintenance schedules and procedures. Past experience indicates a complete integrated solution must be provided for sensor-based control to be used successfully in production. In this paper, Integrated Metrology is proposed as the term for an integrated solution that will result in a successful application of sensors for process control. This paper defines and explores the perceived four elements of successful sensor applications: business needs, integration, components, and form. Based upon analysis of existing successful commercially available controllers, the necessary business factors have been determined to be strong, measurable industry-wide business needs whose solution is profitable and feasible. This paper examines why the key aspect of integration is the decision making process. A detailed discussion is provided of the components of most importance to sensor based control: decision-making methods, the 3R's of sensors, and connectivity. A metric for one of the R's (resolution) is proposed to allow focus on this important aspect of measurement. A form for these integrated components which synergistically partitions various aspects of control at the equipment and MES levels to efficiently achieve desired benefits is recommended.

Electromagnetic analysis of locking device for SMART control element drive mechanism

International Nuclear Information System (INIS)

Heo, H.; Kim, J. I.; Kim, J. H.; Kim, Y. W.; Park, J. S.

1998-01-01

A numerical electromagnetic analysis was performed for the control rod locking device which is installed in the control element drive mechanism of integral reactor, SMART. A plunger model for the electromagnetic analysis of the locking device was developed and theoretical bases for the model were established. Design parameters related to plunger pushing force were identified, and the optimum design point was determined by analyzing the trend of the plunger pushing force with finite element method

Web-based physical activity interventions: a systematic review and meta-analysis of randomized controlled trials.

Science.gov (United States)

Jahangiry, Leila; Farhangi, Mahdieh Abbasalizad; Shab-Bidar, Sakineh; Rezaei, Fatemeh; Pashaei, T

2017-11-01

It was estimated that approximately 60% of the world's population is classified as inactive or insufficiently active. This meta-analysis investigated the effect of web-based interventions on different types of physical activity (PA) measurements in general population and potential moderating variables. PubMed, CINAHL, EBSCOhost, PsycINFO, Scopus, Ovid, and ScienceDirect literature searches were conducted to identify studies investigating the effect of web-based interventions on PA. Randomized controlled trials on PA changes reported in moderate to vigorous intensity, walking, and step count in the intervention group in comparison with the control group were pooled with a fixed-effects model separately. A total of 22 studies comprising 16,476 and 14,475 subjects in intervention and control groups respectively were included. Web-based interventions had positive and significant effect on increasing PA. Of 14 trials reporting moderate to vigorous physical activity (MVPA), five showed a significant increase in the MVPA level after the intervention. There was significant heterogeneity between studies (P < 0.001 and I 2  = 67.8%). Of six trials that reported the number of steps by using the pedometer, three showed a significant increase for the step counts in intervention groups (P < 0.001 and I 2  = 93.3%), of 14 trials assessed PA level by reporting walking minutes per week, four studies showed a significant increase in walking minutes. There was significant heterogeneity between studies (P < 0.001, I 2  = 68.1%). Overall, the effect of web-based interventions seemed to be influenced by the characteristics of mean age of participants, trial duration, and study quality (P < 0.05). The web-based PA interventions had a positive significant effect on increasing all the three types of PA among the general population. However, the effects appear to depend on the design of the study, age, and duration of studies. Copyright © 2017 The Royal Society for Public

Attack tree based cyber security analysis of nuclear digital instrumentation and control systems

International Nuclear Information System (INIS)

Khand, P.A.

2009-01-01

To maintain the cyber security, nuclear digital Instrumentation and Control (I and C) systems must be analyzed for security risks because a single security breach due to a cyber attack can cause system failure, which can have catastrophic consequences on the environment and staff of a Nuclear Power Plant (NPP). Attack trees have been widely used to analyze the cyber security of digital systems due to their ability to capture system specific as well as attacker specific details. Therefore, a methodology based on attack trees has been proposed to analyze the cyber security of the systems. The methodology has been applied for the Cyber Security Analysis (CSA) of a Bistable Processor (BP) of a Reactor Protection System (RPS). Threats have been described according to their source. Attack scenarios have been generated using the attack tree and possible counter measures according to the Security Risk Level (SRL) of each scenario have been suggested. Moreover, cyber Security Requirements (SRs) have been elicited, and suitability of the requirements has been checked. (author)

Analysis of personnel monitoring control card data

International Nuclear Information System (INIS)

Ande, C.D.; Sneha, C.; Madhumita, B.; Bakshi, A.K.; Datta, D.

2018-01-01

In India, personnel monitoring of radiation workers for X-, beta- and gamma- radiation is carried out using a thermoluminescence dosemeter (TLD) system based on CaSO 4 :Dy Teflon TLD disc. A large number of radiation workers get very low occupational doses and their doses are reported as zero since it is not above detectable limits. Therefore, the detection of low levels of occupational dose over and above the natural background assumes great importance. In the present system, the estimation of the background dose is achieved by use of control dosemeters. An analysis of the readings of the control dosimeters sent to various institutions was carried out to arrive at conclusions regarding the validity of the use of control dosimeter

Comparison of adaptive critic-based and classical wide-area controllers for power systems.

Science.gov (United States)

Ray, Swakshar; Venayagamoorthy, Ganesh Kumar; Chaudhuri, Balarko; Majumder, Rajat

2008-08-01

An adaptive critic design (ACD)-based damping controller is developed for a thyristor-controlled series capacitor (TCSC) installed in a power system with multiple poorly damped interarea modes. The performance of this ACD computational intelligence-based method is compared with two classical techniques, which are observer-based state-feedback (SF) control and linear matrix inequality LMI-H(infinity) robust control. Remote measurements are used as feedback signals to the wide-area damping controller for modulating the compensation of the TCSC. The classical methods use a linearized model of the system whereas the ACD method is purely measurement-based, leading to a nonlinear controller with fixed parameters. A comparative analysis of the controllers' performances is carried out under different disturbance scenarios. The ACD-based design has shown promising performance with very little knowledge of the system compared to classical model-based controllers. This paper also discusses the advantages and disadvantages of ACDs, SF, and LMI-H(infinity).

Automated waste canister docking and emplacement using a sensor-based intelligent controller

International Nuclear Information System (INIS)

Drotning, W.D.

1992-08-01

A sensor-based intelligent control system is described that utilizes a multiple degree-of-freedom robotic system for the automated remote manipulation and precision docking of large payloads such as waste canisters. Computer vision and ultrasonic proximity sensing are used to control the automated precision docking of a large object with a passive target cavity. Real-time sensor processing and model-based analysis are used to control payload position to a precision of ± 0.5 millimeter

Stability Analysis of Wireless Measurement and Control System Based on Dynamic Matrix

Directory of Open Access Journals (Sweden)

Yongxian SONG

2014-01-01

Full Text Available Focus on data packet loss and time delay problems in wireless greenhouse measurement and control system, and temperature and humidity were taken as the research objects, the model of temperature and humidity information transmission was set up by decoupling technology according to the characteristics of wireless greenhouse measurement and control system. According to related theory of exponential stability in network control system, the stability conditions judgment of temperature and humidity control model was established, the linear matrix inequality that time delay and packet loss should satisfy was obtained when wireless measurement and control system was stable operation. The feasibility analysis of linear matrix inequality (LMI was implemented Using LMI toolbox in MATLAB, and the critical values of time delay and packet loss rate were obtained when the system was stable operation. The wireless sensor network control system simulation model with time delay and packet loss was set up using TrueTime toolbox. The simulation results have shown that the system was in a stable state when time delay and packet loss rate obtained were less than the critical values in wireless greenhouse sensor network measurement and control system; With the increase of time delay and packet loss rate, and stable performance drops; When time delay and packet loss rate obtained were more than the critical values, the measurement and control system would be in a state of flux, and when it was serious, even can lead to collapse of the whole system. As a result, the critical values determination of time delay and packet loss rate provided a theoretical basis for establishing stable greenhouse wireless sensor network (WSN measurement and control system in practical application.

Variable cycle control model for intersection based on multi-source information

Science.gov (United States)

Sun, Zhi-Yuan; Li, Yue; Qu, Wen-Cong; Chen, Yan-Yan

2018-05-01

In order to improve the efficiency of traffic control system in the era of big data, a new variable cycle control model based on multi-source information is presented for intersection in this paper. Firstly, with consideration of multi-source information, a unified framework based on cyber-physical system is proposed. Secondly, taking into account the variable length of cell, hysteresis phenomenon of traffic flow and the characteristics of lane group, a Lane group-based Cell Transmission Model is established to describe the physical properties of traffic flow under different traffic signal control schemes. Thirdly, the variable cycle control problem is abstracted into a bi-level programming model. The upper level model is put forward for cycle length optimization considering traffic capacity and delay. The lower level model is a dynamic signal control decision model based on fairness analysis. Then, a Hybrid Intelligent Optimization Algorithm is raised to solve the proposed model. Finally, a case study shows the efficiency and applicability of the proposed model and algorithm.

MMS control system analysis using automated root-locus plot generation

International Nuclear Information System (INIS)

Hefler, J.W.

1987-01-01

Use of the Modular Modeling System (MMS) for control systems improvement has been impeded by the need to plot eigenvalues manually. This problem has been solved by an automatic eigenvalue plotting routine. A practical procedure for control systems analysis based upon automatically generated root-locus plots has been developed using the Advanced Continuous Simulation Language (ACSL)-based version of the Modular Modeling System. Examples are given of typical ACSL run-time statements. Actual root-locus and time history plots are shown for simple models (4 state variables). More complex models are discussed. The plots show the control systems response before and after the determination of tuning parameters using the methods described

Application of REVEAL-W to risk-based configuration control

International Nuclear Information System (INIS)

Dezfuli, H.; Meyer, J.; Modarres, M.

1994-01-01

Over the past two years, the concept of risk-based configuration control has been introduced to the US Nuclear Regulatory Commission and the nuclear industry. Converting much of the current, deterministically based regulation of nuclear power plants to risk-based regulation can result in lower levels of risk while relieving unnecessary burdens on power plant operators and regulatory staff. To achieve the potential benefits of risk-based configuration control, the risk models developed for nuclear power plants should be (1) flexible enough to effectively support necessary risk calculations, and (2) transparent enough to encourage their use by all parties. To address these needs, SCIENTECH, Inc., has developed the PC-based REVEAL W (formerly known as SMART). This graphic-oriented and user-friendly application software allows the user to develop transparent complex logic models based on the concept of the master plant logic diagram. The logic model is success-oriented and compact. The analytical capability built into REVEAL W is generic, so the software can support different types of risk-based evaluations, such as probabilistic safety assessment, accident sequence precursor analysis, design evaluation and configuration management. In this paper, we focus on the application of REVEAL W to support risk-based configuration control of nuclear power plants. (author)

IQC-based robust stability analysis for LPV control of doubly-fed induction generators

NARCIS (Netherlands)

Tien, H. N.; Scherer, C. W.; Scherpen, J. M. A.

2008-01-01

Parameters of electrical machines are usually varying with time in a smooth way due to changing operating conditions, such as variations in the machine temperature and/or the magnetic saturation. This paper is concerned with robust stability analysis of controlled Doubly-Fed Induction Generators

Voxel-based morphometry and voxel-based diffusion tensor analysis in amyotrophic lateral sclerosis

International Nuclear Information System (INIS)

Chen Zhiye; Ma Lin; Lou Xin; Wang Yan

2010-01-01

Objective: To evaluate gray matter volume, white matter volume and FA value changes in amyatrophic lateral sclerosis (ALS) patients by voxel-based morphometry (VBM) and voxel-based diffusion tensor analysis (VBDTA). Methods: Thirty-nine definite or probable ALS patients diagnosed by El Escorial standard and 39 healthy controls were recruited and underwent conventional MR scans and the neuropsychological evaluation. The 3D FSPGR T 1 WI and DTI data were collected on GE Medical 3.0 T MRI system. The 3DT 1 structural images were normalized, segmented and smoothed, and then VBM analysis was performed. DTI data were acquired from 76 healthy controls, and FA map template was made. FA maps generated from the DTI data of ALS patients and healthy controls were normalized to the FA map template for voxel-based analysis. ANCOVA was applied, controlling with age and total intracranial volume for VBM and age for VBDDTA. A statistical threshold of P<0.01 (uncorrected) and cluster level of more than continuous 20 voxels determined significance. Results: Statistical results showed no significant difference in the global volumes of gray matter and white matter, total intracranial volumes and gray matter fraction between ALS patients and healthy controls, but the white matter fraction of ALS patients (0.29 ± 0.02) was significantly less than that of healthy controls (0.30 ± 0.02) statistically (P=0.003). There was significant reduction of gray matter volumes in bilateral superior frontal gyri and precentral gyri, right middle frontal gyrus, right middle and inferior temporal gyrus, left superior occipital gyrus and cuneus and left insula in ALS patients when compared with healthy controls; and the regional reduction of white matter volumes in ALS patients mainly located in genu of corpus callosum, bilateral medial frontal gyri, paracentral lobule and insula, right superior and middle frontal gyrus and left postcentral gyrus. VBDTA showed decrease in FA values in bilateral

Comparison of intelligent fuzzy based AGC coordinated PID controlled and PSS controlled AVR system

Energy Technology Data Exchange (ETDEWEB)

Mukherjee, V. [Department of Electrical Engineering, Asansol Engineering College, Asansol, West Bengal (India); Ghoshal, S.P. [Department of Electrical Engineering, National Institute of Technology, Durgapur, West Bengal (India)

2007-11-15

This paper attempts to investigate the performance of intelligent fuzzy based coordinated control of the Automatic Generation Control (AGC) loop and the excitation loop equipped with Proportional Integral Derivative (PID) controlled Automatic Voltage Regulator (AVR) system and Power System Stabilizer (PSS) controlled AVR system. The work establishes that PSS controlled AVR system is much more robust in dynamic performance of the system over a wide range of system operating configurations. Thus, it is revealed that PSS equipped AVR is much more superior than PID equipped AVR in damping the oscillation resulting in improved transient response. The paper utilizes a novel class of Particle Swarm Optimization (PSO) termed as Craziness based Particle Swarm Optimization (CRPSO) as optimizing tool to get optimal tuning of PSS parameters as well as the gains of PID controllers. For on-line, off-nominal operating conditions Takagi Sugeno Fuzzy Logic (TSFL) has been applied to obtain the off-nominal optimal gains of PID controllers and parameters of PSS. Implementation of TSFL helps to achieve very fast dynamic response. Fourth order model of generator with AVR and high gain thyristor excitation system is considered for PSS controlled system while normal gain exciter is considered for PID controlled system. Simulation study also reveals that with high gain exciter, PID control is not at all effective. Transient responses are achieved by using modal analysis. (author)

Technical Requirements Analysis and Control Systems (TRACS) Initial Operating Capability (IOC) documentation

Science.gov (United States)

Hammond, Dana P.

1991-01-01

The Technical Requirements Analysis and Control Systems (TRACS) software package is described. TRACS offers supplemental tools for the analysis, control, and interchange of project requirements. This package provides the fundamental capability to analyze and control requirements, serves a focal point for project requirements, and integrates a system that supports efficient and consistent operations. TRACS uses relational data base technology (ORACLE) in a stand alone or in a distributed environment that can be used to coordinate the activities required to support a project through its entire life cycle. TRACS uses a set of keyword and mouse driven screens (HyperCard) which imposes adherence through a controlled user interface. The user interface provides an interactive capability to interrogate the data base and to display or print project requirement information. TRACS has a limited report capability, but can be extended with PostScript conventions.

Coordinated Pitch & Torque Control of Large-Scale Wind Turbine Based on Pareto Eciency Analysis

DEFF Research Database (Denmark)

Lin, Zhongwei; Chen, Zhenyu; Wu, Qiuwei

2018-01-01

For the existing pitch and torque control of the wind turbine generator system (WTGS), further development on coordinated control is necessary to improve effectiveness for practical applications. In this paper, the WTGS is modeled as a coupling combination of two subsystems: the generator torque...... control subsystem and blade pitch control subsystem. Then, the pole positions in each control subsystem are adjusted coordinately to evaluate the controller participation and used as the objective of optimization. A two-level parameters-controllers coordinated optimization scheme is proposed and applied...... to optimize the controller coordination based on the Pareto optimization theory. Three solutions are obtained through optimization, which includes the optimal torque solution, optimal power solution, and satisfactory solution. Detailed comparisons evaluate the performance of the three selected solutions...

Optimized Aircraft Electric Control System Based on Adaptive Tabu Search Algorithm and Fuzzy Logic Control

Directory of Open Access Journals (Sweden)

Saifullah Khalid

2016-09-01

Full Text Available Three conventional control constant instantaneous power control, sinusoidal current control, and synchronous reference frame techniques for extracting reference currents for shunt active power filters have been optimized using Fuzzy Logic control and Adaptive Tabu search Algorithm and their performances have been compared. Critical analysis of Comparison of the compensation ability of different control strategies based on THD and speed will be done, and suggestions will be given for the selection of technique to be used. The simulated results using MATLAB model are presented, and they will clearly prove the value of the proposed control method of aircraft shunt APF. The waveforms observed after the application of filter will be having the harmonics within the limits and the power quality will be improved.

FEATURE EXTRACTION FOR EMG BASED PROSTHESES CONTROL

Directory of Open Access Journals (Sweden)

R. Aishwarya

2013-01-01

Full Text Available The control of prosthetic limb would be more effective if it is based on Surface Electromyogram (SEMG signals from remnant muscles. The analysis of SEMG signals depend on a number of factors, such as amplitude as well as time- and frequency-domain properties. Time series analysis using Auto Regressive (AR model and Mean frequency which is tolerant to white Gaussian noise are used as feature extraction techniques. EMG Histogram is used as another feature vector that was seen to give more distinct classification. The work was done with SEMG dataset obtained from the NINAPRO DATABASE, a resource for bio robotics community. Eight classes of hand movements hand open, hand close, Wrist extension, Wrist flexion, Pointing index, Ulnar deviation, Thumbs up, Thumb opposite to little finger are taken into consideration and feature vectors are extracted. The feature vectors can be given to an artificial neural network for further classification in controlling the prosthetic arm which is not dealt in this paper.

Man-machine interfaces analysis system based on computer simulation

International Nuclear Information System (INIS)

Chen Xiaoming; Gao Zuying; Zhou Zhiwei; Zhao Bingquan

2004-01-01

The paper depicts a software assessment system, Dynamic Interaction Analysis Support (DIAS), based on computer simulation technology for man-machine interfaces (MMI) of a control room. It employs a computer to simulate the operation procedures of operations on man-machine interfaces in a control room, provides quantified assessment, and at the same time carries out analysis on operational error rate of operators by means of techniques for human error rate prediction. The problems of placing man-machine interfaces in a control room and of arranging instruments can be detected from simulation results. DIAS system can provide good technical supports to the design and improvement of man-machine interfaces of the main control room of a nuclear power plant

Performance Analysis of Quality-of-Service Controls in a Cell-Cluster-Based Wireless ATM Network

Energy Technology Data Exchange (ETDEWEB)

Cho, Young Jong [Ajou University, Suwon (Korea, Republic of)

1997-04-01

In this paper, an efficient cell-cluster-based call control scheme with guaranteed quality-of-service(QoS) provision ing is presented for next generation wireless ATM networks and its performance is mathematically analyzed using the open queuing network. With the cell-cluster-based call control, at the time a mobile connection is admitted to the network, a virtual cell is constructed by choosing a group of neighboring base stations to which the call may probabilistic ally hand over and by assigning to the call a collection of virtual paths between the base stations. Within a micro cell/pico cell environment, it is seen that the cell-cluster-based call control can support effectively a very high rate of handovers, provides very high system capacity, and guarantees a high degree of frequency reuse over the same geographical region without requiring the intervention of the network call control processor each time a handover occurs. But since mobiles, once admitted, are free to roam within the virtual cell, congestion condition occurs in which the number of calls to be handled by one base station exceeds the cell sites` capacity of radio channel and consequently a predefined QoS provision cannot be guaranteed. So, there must be a call admission control function to limit the number of calls existing in a cell-cluster such that required QoS objectives are met. As call acceptance criteria for constant-bit-rate or realtime variable-bit-rate ATM connections, we define four mobile QoS metrics: new-call blocking probability, wireless channel utilization efficiency, congestion probability and normalized average congestion duration. In addition, for QoS provision ing to available-bit-rate, unspecified-bit-rate or non-realtime variable-bit-rate connections, we further define another QoS metric, the minimum threshold breaking probability. By using the open network queuing model, we derive closed form expressions for the five QoS metrics defined above and show that they can be

Time series modeling for analysis and control advanced autopilot and monitoring systems

CERN Document Server

Ohtsu, Kohei; Kitagawa, Genshiro

2015-01-01

This book presents multivariate time series methods for the analysis and optimal control of feedback systems. Although ships’ autopilot systems are considered through the entire book, the methods set forth in this book can be applied to many other complicated, large, or noisy feedback control systems for which it is difficult to derive a model of the entire system based on theory in that subject area. The basic models used in this method are the multivariate autoregressive model with exogenous variables (ARX) model and the radial bases function net-type coefficients ARX model. The noise contribution analysis can then be performed through the estimated autoregressive (AR) model and various types of autopilot systems can be designed through the state–space representation of the models. The marine autopilot systems addressed in this book include optimal controllers for course-keeping motion, rolling reduction controllers with rudder motion, engine governor controllers, noise adaptive autopilots, route-tracki...

Temperature control characteristics analysis of lead-cooled fast reactor with natural circulation

International Nuclear Information System (INIS)

Yang, Minghan; Song, Yong; Wang, Jianye; Xu, Peng; Zhang, Guangyu

2016-01-01

Highlights: • The LFR temperature control system are analyzed with frequency domain method. • The temperature control compensator is designed according to the frequency analysis. • Dynamic simulation is performed by SIMULINK and RELAP5-HD. - Abstract: Lead-cooled Fast Reactor (LFR) with natural circulation in primary system is among the highlights in advance nuclear reactor research, due to its great superiority in reactor safety and reliability. In this work, a transfer function matrix describing coolant temperature dynamic process, obtained by Laplace transform of the one-dimensional system dynamic model is developed in order to investigate the temperature control characteristics of LFR. Based on the transfer function matrix, a close-loop coolant temperature control system without compensator is built. The frequency domain analysis indicates that the stability and steady-state of the temperature control system needs to be improved. Accordingly, a temperature compensator based on Proportion–Integration and feed-forward is designed. The dynamic simulation of the whole system with the temperature compensator for core power step change is performed with SIMULINK and RELAP5-HD. The result shows that the temperature compensator can provide superior coolant temperature control capabilities in LFR with natural circulation due to the efficiency of the frequency domain analysis method.

Electromagnetic analysis of locking device for SMART control element drive mechanism

Energy Technology Data Exchange (ETDEWEB)

Huh, Hyung; Kim, J. I.; Kim, J. H. [Korea Atomic Energy Research Institute, Taejon (Korea)

1998-09-01

A numerical electromagnetic analysis was performed for the control rod locking device which is installed in the control element drive mechanism of integral reactor, SMART. A plunger model for the electromagnetic analysis of the locking device was developed and theoretical bases for the model were established. Design parameters related to plunger pushing force were identified, and the optimum design point was determined by analysing the trend of the plunger pushing force with finite element method. 8 refs., 22 figs., 2 tabs. (Author)

ATLAS tile calorimeter cesium calibration control and analysis software

International Nuclear Information System (INIS)

Solovyanov, O; Solodkov, A; Starchenko, E; Karyukhin, A; Isaev, A; Shalanda, N

2008-01-01

An online control system to calibrate and monitor ATLAS Barrel hadronic calorimeter (TileCal) with a movable radioactive source, driven by liquid flow, is described. To read out and control the system an online software has been developed, using ATLAS TDAQ components like DVS (Diagnostic and Verification System) to verify the hardware before running, IS (Information Server) for data and status exchange between networked computers, and other components like DDC (DCS to DAQ Connection), to connect to PVSS-based slow control systems of Tile Calorimeter, high voltage and low voltage. A system of scripting facilities, based on Python language, is used to handle all the calibration and monitoring processes from hardware perspective to final data storage, including various abnormal situations. A QT based graphical user interface to display the status of the calibration system during the cesium source scan is described. The software for analysis of the detector response, using online data, is discussed. Performance of the system and first experience from the ATLAS pit are presented

ATLAS tile calorimeter cesium calibration control and analysis software

Energy Technology Data Exchange (ETDEWEB)

Solovyanov, O; Solodkov, A; Starchenko, E; Karyukhin, A; Isaev, A; Shalanda, N [Institute for High Energy Physics, Protvino 142281 (Russian Federation)], E-mail: Oleg.Solovyanov@ihep.ru

2008-07-01

An online control system to calibrate and monitor ATLAS Barrel hadronic calorimeter (TileCal) with a movable radioactive source, driven by liquid flow, is described. To read out and control the system an online software has been developed, using ATLAS TDAQ components like DVS (Diagnostic and Verification System) to verify the hardware before running, IS (Information Server) for data and status exchange between networked computers, and other components like DDC (DCS to DAQ Connection), to connect to PVSS-based slow control systems of Tile Calorimeter, high voltage and low voltage. A system of scripting facilities, based on Python language, is used to handle all the calibration and monitoring processes from hardware perspective to final data storage, including various abnormal situations. A QT based graphical user interface to display the status of the calibration system during the cesium source scan is described. The software for analysis of the detector response, using online data, is discussed. Performance of the system and first experience from the ATLAS pit are presented.

Inelastic Structural Control Based on MBC and FAM

Directory of Open Access Journals (Sweden)

Li Gang

2011-01-01

Full Text Available A complex structure has the characters of many degrees of freedom and intricate shape, especially inelastic behavior under strong external loadings. It is hard to apply the structural control technology to it. In this paper, a new method that combines the Market-Based Control (MBC strategy and Force Analogy Method (FAM is presented to analyze the inelastic behavior of structure with magnetorheological dampers. The MBC is used to reduce the structural vibration response, and FAM is proposed to perform the inelastic analysis. A numerical example is used to compare the control effect of the new method and LQR algorithm, which show the accuracy and efficiency of the proposed computational method.

Small, microcomputer-based CAMAC controller

International Nuclear Information System (INIS)

Juras, R.C.

1979-01-01

The beam buncher necessary to condition the beam from the Oak Ridge National Laboratory 25 MV tandem accelerator for post-acceleration by the Oak Ridge Isochronous Cyclotron is CAMAC-based and will be controlled via one of the serial highways of the accelerator control system. However, prior to integration into the accelerator system, the buncher requires testing, including runs on the model EN tandem at Oak Ridge. In order to facilitate testing and initial operation of the buncher, a microcomputer-based controller was assembled. The controller consists of a CAMAC crate, several CAMAC modules, a touch panel display, a controller box, and software. The controller box contains one shaft encoder and two switches. One of the switches is a coarse/fine selector. The other switch is assignable via the touch panel display and is used, for example, to turn devices on and off. Operation of the controller is described. It can be quickly assembled to control any small CAMAC-based system. 2 figures

A Novel Method of Robust Trajectory Linearization Control Based on Disturbance Rejection

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Xingling Shao

2014-01-01

Full Text Available A novel method of robust trajectory linearization control for a class of nonlinear systems with uncertainties based on disturbance rejection is proposed. Firstly, on the basis of trajectory linearization control (TLC method, a feedback linearization based control law is designed to transform the original tracking error dynamics to the canonical integral-chain form. To address the issue of reducing the influence made by uncertainties, with tracking error as input, linear extended state observer (LESO is constructed to estimate the tracking error vector, as well as the uncertainties in an integrated manner. Meanwhile, the boundedness of the estimated error is investigated by theoretical analysis. In addition, decoupled controller (which has the characteristic of well-tuning and simple form based on LESO is synthesized to realize the output tracking for closed-loop system. The closed-loop stability of the system under the proposed LESO-based control structure is established. Also, simulation results are presented to illustrate the effectiveness of the control strategy.

Alignment Condition-Based Robust Adaptive Iterative Learning Control of Uncertain Robot System

Directory of Open Access Journals (Sweden)

Guofeng Tong

2014-04-01

Full Text Available This paper proposes an adaptive iterative learning control strategy integrated with saturation-based robust control for uncertain robot system in presence of modelling uncertainties, unknown parameter, and external disturbance under alignment condition. An important merit is that it achieves adaptive switching of gain matrix both in conventional PD-type feedforward control and robust adaptive control in the iteration domain simultaneously. The analysis of convergence of proposed control law is based on Lyapunov's direct method under alignment initial condition. Simulation results demonstrate the faster learning rate and better robust performance with proposed algorithm by comparing with other existing robust controllers. The actual experiment on three-DOF robot manipulator shows its better practical effectiveness.

Analysis of the Effects of Thermal Environment on Optical Systems for Navigation Guidance and Control in Supersonic Aircraft Based on Empirical Equations.

Science.gov (United States)

Cheng, Xuemin; Yang, Yikang; Hao, Qun

2016-10-17

The thermal environment is an important factor in the design of optical systems. This study investigated the thermal analysis technology of optical systems for navigation guidance and control in supersonic aircraft by developing empirical equations for the front temperature gradient and rear thermal diffusion distance, and for basic factors such as flying parameters and the structure of the optical system. Finite element analysis (FEA) was used to study the relationship between flying and front dome parameters and the system temperature field. Systematic deduction was then conducted based on the effects of the temperature field on the physical geometry and ray tracing performance of the front dome and rear optical lenses, by deriving the relational expressions between the system temperature field and the spot size and positioning precision of the rear optical lens. The optical systems used for navigation guidance and control in supersonic aircraft when the flight speed is in the range of 1-5 Ma were analysed using the derived equations. Using this new method it was possible to control the precision within 10% when considering the light spot received by the four-quadrant detector, and computation time was reduced compared with the traditional method of separately analysing the temperature field of the front dome and rear optical lens using FEA. Thus, the method can effectively increase the efficiency of parameter analysis and computation in an airborne optical system, facilitating the systematic, effective and integrated thermal analysis of airborne optical systems for navigation guidance and control.

Quantitative Analysis of the Security of Software-Defined Network Controller Using Threat/Effort Model

Directory of Open Access Journals (Sweden)

Zehui Wu

2017-01-01

Full Text Available SDN-based controller, which is responsible for the configuration and management of the network, is the core of Software-Defined Networks. Current methods, which focus on the secure mechanism, use qualitative analysis to estimate the security of controllers, leading to inaccurate results frequently. In this paper, we employ a quantitative approach to overcome the above shortage. Under the analysis of the controller threat model we give the formal model results of the APIs, the protocol interfaces, and the data items of controller and further provide our Threat/Effort quantitative calculation model. With the help of Threat/Effort model, we are able to compare not only the security of different versions of the same kind controller but also different kinds of controllers and provide a basis for controller selection and secure development. We evaluated our approach in four widely used SDN-based controllers which are POX, OpenDaylight, Floodlight, and Ryu. The test, which shows the similarity outcomes with the traditional qualitative analysis, demonstrates that with our approach we are able to get the specific security values of different controllers and presents more accurate results.

Quality control and performance evaluation of k0-based neutron activation analysis at the Portuguese research reactor

International Nuclear Information System (INIS)

Dung, H.M.; Freitas, M.C.; Blaauw, M.; Almeida, S.M.; Dionisio, I.; Canha, N.H.

2010-01-01

The quality control (QC) and performance evaluation for the k 0 -based neutron activation analysis (k 0 -NAA) at the Portuguese research reactor (RPI) has been developed with the intention of using the method to meet the demands of trace element analysis for the applications in environmental, epidemiological and nutritional studies amongst others. The QC and performance evaluation include the following aspects: (1) estimation of the overall/combined standard uncertainty from the primary uncertainty sources; (2) validation of the method using a synthetic multi-element standard (SMELS); and (3) analysis of the certified reference materials from the National Institute of Standards and Technology (USA): NIST-SRM-1633a and NIST-SRM-1648 and the reference material from the International Atomic Energy Agency: IAEA-RM-336, for the purpose of controlling the overall accuracy and precision of the analytical results. The obtained results revealed that the k 0 -NAA method established at the RPI was fit for the purpose. The overall/combined standard uncertainty was estimated for elements of interest in the intended applications. The laboratory's analytical results as compared to the assigned values with the bias were less than 12% for most elements, except for a few elements which biased within 13-18%. The u-score values for most elements were less than |1.64|, except for Co, La and Ti within |1.64|-|1.96| and Sc, Cr, K and Sb within |1.96|-|2.58|. The NIST-1633a was also analyzed over 14 months for the purpose of evaluating the reproducibility of the method. The quality factors of k 0 -NAA established at RPI were evaluated, proving that the method meets the requirements of trace element analysis, which is also considering the method's performance for which the k 0 -NAA affords a specific, rapid and convenient capability for the intended applications.

Structural analysis and design of multivariable control systems: An algebraic approach

Science.gov (United States)

Tsay, Yih Tsong; Shieh, Leang-San; Barnett, Stephen

1988-01-01

The application of algebraic system theory to the design of controllers for multivariable (MV) systems is explored analytically using an approach based on state-space representations and matrix-fraction descriptions. Chapters are devoted to characteristic lambda matrices and canonical descriptions of MIMO systems; spectral analysis, divisors, and spectral factors of nonsingular lambda matrices; feedback control of MV systems; and structural decomposition theories and their application to MV control systems.

Fuzzy logic-based advanced on–off control for thermal comfort in residential buildings

International Nuclear Information System (INIS)

Kang, Chang-Soon; Hyun, Chang-Ho; Park, Mignon

2015-01-01

Highlights: • Fuzzy logic-based advanced on–off control is proposed. • An anticipative control mechanism is implemented by using fuzzy theory. • Novel thermal analysis program including solar irradiation as a factor is developed. • The proposed controller solves over-heating and under-heating thermal problems. • Solar energy compensation method is applied to compensate for the solar energy. - Abstract: In this paper, an advanced on–off control method based on fuzzy logic is proposed for maintaining thermal comfort in residential buildings. Due to the time-lag of the control systems and the late building thermal response, an anticipative control mechanism is required to reduce energy loss and thermal discomfort. The proposed controller is implemented based on an on–off controller combined with a fuzzy algorithm. On–off control was chosen over other conventional control methods because of its structural simplicity. However, because conventional on–off control has a fixed operating range and a limited ability for improvements in control performance, fuzzy theory can be applied to overcome these limitations. Furthermore, a fuzzy-based solar energy compensation algorithm can be applied to the proposed controller to compensate for the energy gained from solar radiation according to the time of day. Simulations were conducted to compare the proposed controller with a conventional on–off controller under identical external conditions such as outdoor temperature and solar energy; these simulations were carried out by using a previously reported thermal analysis program that was modified to consider such external conditions. In addition, experiments were conducted in a residential building called Green Home Plus, in which hydronic radiant floor heating is used; in these experiments, the proposed system performed better than a system employing conventional on–off control methods

Simulation Research on Vehicle Active Suspension Controller Based on G1 Method

Science.gov (United States)

Li, Gen; Li, Hang; Zhang, Shuaiyang; Luo, Qiuhui

2017-09-01

Based on the order relation analysis method (G1 method), the optimal linear controller of vehicle active suspension is designed. The system of the main and passive suspension of the single wheel vehicle is modeled and the system input signal model is determined. Secondly, the system motion state space equation is established by the kinetic knowledge and the optimal linear controller design is completed with the optimal control theory. The weighting coefficient of the performance index coefficients of the main passive suspension is determined by the relational analysis method. Finally, the model is simulated in Simulink. The simulation results show that: the optimal weight value is determined by using the sequence relation analysis method under the condition of given road conditions, and the vehicle acceleration, suspension stroke and tire motion displacement are optimized to improve the comprehensive performance of the vehicle, and the active control is controlled within the requirements.

Analysis of rare, exonic variation amongst subjects with autism spectrum disorders and population controls.

Directory of Open Access Journals (Sweden)

Li Liu

2013-04-01

Full Text Available We report on results from whole-exome sequencing (WES of 1,039 subjects diagnosed with autism spectrum disorders (ASD and 870 controls selected from the NIMH repository to be of similar ancestry to cases. The WES data came from two centers using different methods to produce sequence and to call variants from it. Therefore, an initial goal was to ensure the distribution of rare variation was similar for data from different centers. This proved straightforward by filtering called variants by fraction of missing data, read depth, and balance of alternative to reference reads. Results were evaluated using seven samples sequenced at both centers and by results from the association study. Next we addressed how the data and/or results from the centers should be combined. Gene-based analyses of association was an obvious choice, but should statistics for association be combined across centers (meta-analysis or should data be combined and then analyzed (mega-analysis? Because of the nature of many gene-based tests, we showed by theory and simulations that mega-analysis has better power than meta-analysis. Finally, before analyzing the data for association, we explored the impact of population structure on rare variant analysis in these data. Like other recent studies, we found evidence that population structure can confound case-control studies by the clustering of rare variants in ancestry space; yet, unlike some recent studies, for these data we found that principal component-based analyses were sufficient to control for ancestry and produce test statistics with appropriate distributions. After using a variety of gene-based tests and both meta- and mega-analysis, we found no new risk genes for ASD in this sample. Our results suggest that standard gene-based tests will require much larger samples of cases and controls before being effective for gene discovery, even for a disorder like ASD.

Analysis of Rare, Exonic Variation amongst Subjects with Autism Spectrum Disorders and Population Controls

Science.gov (United States)

Liu, Li; Sabo, Aniko; Neale, Benjamin M.; Nagaswamy, Uma; Stevens, Christine; Lim, Elaine; Bodea, Corneliu A.; Muzny, Donna; Reid, Jeffrey G.; Banks, Eric; Coon, Hillary; DePristo, Mark; Dinh, Huyen; Fennel, Tim; Flannick, Jason; Gabriel, Stacey; Garimella, Kiran; Gross, Shannon; Hawes, Alicia; Lewis, Lora; Makarov, Vladimir; Maguire, Jared; Newsham, Irene; Poplin, Ryan; Ripke, Stephan; Shakir, Khalid; Samocha, Kaitlin E.; Wu, Yuanqing; Boerwinkle, Eric; Buxbaum, Joseph D.; Cook, Edwin H.; Devlin, Bernie; Schellenberg, Gerard D.; Sutcliffe, James S.; Daly, Mark J.; Gibbs, Richard A.; Roeder, Kathryn

2013-01-01

We report on results from whole-exome sequencing (WES) of 1,039 subjects diagnosed with autism spectrum disorders (ASD) and 870 controls selected from the NIMH repository to be of similar ancestry to cases. The WES data came from two centers using different methods to produce sequence and to call variants from it. Therefore, an initial goal was to ensure the distribution of rare variation was similar for data from different centers. This proved straightforward by filtering called variants by fraction of missing data, read depth, and balance of alternative to reference reads. Results were evaluated using seven samples sequenced at both centers and by results from the association study. Next we addressed how the data and/or results from the centers should be combined. Gene-based analyses of association was an obvious choice, but should statistics for association be combined across centers (meta-analysis) or should data be combined and then analyzed (mega-analysis)? Because of the nature of many gene-based tests, we showed by theory and simulations that mega-analysis has better power than meta-analysis. Finally, before analyzing the data for association, we explored the impact of population structure on rare variant analysis in these data. Like other recent studies, we found evidence that population structure can confound case-control studies by the clustering of rare variants in ancestry space; yet, unlike some recent studies, for these data we found that principal component-based analyses were sufficient to control for ancestry and produce test statistics with appropriate distributions. After using a variety of gene-based tests and both meta- and mega-analysis, we found no new risk genes for ASD in this sample. Our results suggest that standard gene-based tests will require much larger samples of cases and controls before being effective for gene discovery, even for a disorder like ASD. PMID:23593035

Control assembly ejection accident analysis for WWER-440 (Armenian NPP)

International Nuclear Information System (INIS)

Bznuni, S.; Malakyan, Ts.; Amirjanyan, A.; Ghasabyan, L.

2007-01-01

Control Assembly ejection in WWER-440 initiated by the loss of integrity of the Control Assemblies drive housing has been analyzed. This event causes a very rapid reactivity insertion to the core and small break LOCA which potentially could lead to rapid power increase and redistribution of heat release in the core resulting in a fuel, cladding and coolant temperature rise; primary pressure increase, radiological consequences due to loss of primary coolant and potential loss of cladding integrity and fuel disintegration (if applicable). Methodology of the analysis is based on conservative assumptions as well as on deterministic approach for selection of functioning logic of systems and equipment's to maximize reactor core power and minimize power decreasing reactivity feedback. Computational analyses were performed by 3D kinetics PARCS-RELAP coupled code. WWER-440 fuel cross-section libraries, diffusion coefficients and kinetics parameters were calculated by HELOS code. In this paper analysis of accident for Hot Full Power was presented. Results of analysis show that ANPP WWER-440 reactor design meets acceptance criteria prescribed for RIA type design based accidents (Authors)

The role of function analysis in the ACR control centre design

International Nuclear Information System (INIS)

Leger, R.P.; Davey, E.C.

2006-01-01

An essential aspect of control centre design is the need to characterize: plant functions and their inter-relationships to support the achievement of operational goals, and roles for humans and automation in sharing and exchanging the execution of functions across all operational phases. Function analysis is a design activity that has been internationally accepted as an approach to satisfy this need. It is recognized as a fundamental and necessary component in the systematic approach to control centre design and is carried out early in the design process. A function analysis can provide a clear basis for: the control centre design for the purposes of design team communication, and customer or regulatory review, the control centre display and control systems, the staffing and layout requirements of the control centre, assessing the completeness of control centre displays and controls prior and supplementary to mock-up walkthroughs or simulator evaluations, and the design of operating procedures and training programs. This paper will explore the role for function analysis in supporting the design of the control centre. The development of the ACR control room will be used as an illustrative context for the discussion. The paper will also discuss the merits of using function analysis in a goal-or function-based approach resulting in a more robust, operationally compatible, and cost-effective design over the life of the plant. Two former papers have previously outlined, the evolution in AECL's application approach and lessons learned in applying function analysis in support of control room design. This paper provides the most recent update to this progression in application refinement. (author)

Owner-Based Role-Based Access Control OB-RBAC

NARCIS (Netherlands)

Saffarian, M.; Sadighi, Babak

Administration of an access control model deals with the question of who is authorized to update policies defined on the basis of that model. One of the models whose administration has absorbed relatively large research is the Role-Based Access Control (RBAC) model. All the existing role-based

Versatile microcomputer-based temperature controller

International Nuclear Information System (INIS)

Yarberry, V.R.

1980-09-01

The wide range of thermal responses required in laboratory and scientific equipment requires a temperature controller with a great deal of flexibility. While a number of analog temperature controllers are commercially available, they have certain limitations, such as inflexible parameter control or insufficient precision. Most lack digital interface capabilities--a necessity when the temperature controller is part of a computer-controlled automatic data acquisition system. We have developed an extremely versatile microcomputer-based temperature controller to fulfill this need in a variety of equipment. The control algorithm used allows optimal tailoring of parameters to control overshoot, response time, and accuracy. This microcomputer-based temperature controller can be used as a standalone instrument (with a teletype used to enter para-meters), or it can be integrated into a data acquisition system

Genome analysis and DNA marker-based characterisation of pathogenic trypanosomes

NARCIS (Netherlands)

Agbo, Edwin Chukwura

2003-01-01

The advances in genomics technologies and genome analysis methods that offer new leads for accelerating discovery of putative targets for developing overall control tools are reviewed in Chapter 1. In Chapter 2, a PCR typing method based on restriction fragment length polymorphism analysis of the

Model-based safety analysis of a control system using Simulink and Simscape extended models

Directory of Open Access Journals (Sweden)

Shao Nian

2017-01-01

Full Text Available The aircraft or system safety assessment process is an integral part of the overall aircraft development cycle. It is usually characterized by a very high timely and financial effort and can become a critical design driver in certain cases. Therefore, an increasing demand of effective methods to assist the safety assessment process arises within the aerospace community. One approach is the utilization of model-based technology, which is already well-established in the system development, for safety assessment purposes. This paper mainly describes a new tool for Model-Based Safety Analysis. A formal model for an example system is generated and enriched with extended models. Then, system safety analyses are performed on the model with the assistance of automation tools and compared to the results of a manual analysis. The objective of this paper is to improve the increasingly complex aircraft systems development process. This paper develops a new model-based analysis tool in Simulink/Simscape environment.

Walking dynamics of the passive compass-gait model under OGY-based state-feedback control: Analysis of local bifurcations via the hybrid Poincaré map

International Nuclear Information System (INIS)

Gritli, Hassène; Belghith, Safya

2017-01-01

Highlights: • We study the passive walking dynamics of the compass-gait model under OGY-based state-feedback control. • We analyze local bifurcations via a hybrid Poincaré map. • We show exhibition of the super(sub)-critical flip bifurcation, the saddle-node(saddle) bifurcation and a saddle-flip bifurcation. • An analysis via a two-parameter bifurcation diagram is presented. • Some new hidden attractors in the controlled passive walking dynamics are displayed. - Abstract: In our previous work, we have analyzed the passive dynamic walking of the compass-gait biped model under the OGY-based state-feedback control using the impulsive hybrid nonlinear dynamics. Such study was carried out through bifurcation diagrams. It was shown that the controlled bipedal gait exhibits attractive nonlinear phenomena such as the cyclic-fold (saddle-node) bifurcation, the period-doubling (flip) bifurcation and chaos. Moreover, we revealed that, using the controlled continuous-time dynamics, we encountered a problem in finding, identifying and hence following branches of (un)stable solutions in order to characterize local bifurcations. The present paper solves such problem and then provides a further investigation of the controlled bipedal walking dynamics using the developed analytical expression of the controlled hybrid Poincaré map. Thus, we show that analysis via such Poincaré map allows to follow branches of both stable and unstable fixed points in bifurcation diagrams and hence to explore the complete dynamics of the controlled compass-gait biped model. We demonstrate the generation, other than the conventional local bifurcations in bipedal walking, i.e. the flip bifurcation and the saddle-node bifurcation, of a saddle-saddle bifurcation, a subcritical flip bifurcation and a new type of a local bifurcation, the saddle-flip bifurcation. In addition, to further understand the occurrence of the local bifurcations, we present an analysis with a two-parameter bifurcation

Use of task analysis in control room evaluations

International Nuclear Information System (INIS)

Ross, K.C.

1981-01-01

Responding to recently formulated regulatory requirements, the BWR Owners' Group, working in conjunction with General Electric, has formulated a method for performing human factors design reviews of nuclear power plant control rooms. This process incorporates task analyses to analyze operational aspects of panel layout and design. Correlation of operator functions defined by emergency procedures against required controls and displays has proven successful in identifying instrumentation required in the control room to adequately respond to transient conditions, and in evaluating the effectiveness of panel design and physical arrangement. Extensions of the analysis have provided information on operator response paths, frequency of use of instruments, and control room layout. The techniques used were based on a need to identify primary controls and indications required by the operator in performing each step of the applicable procedure. The relative locations of these instruments were then analyzed for information on the adequacy of the control room design for those conditions

Possibilities to employ noise analysis techniques in controlling nuclear power stations

International Nuclear Information System (INIS)

Alfonso Pallares, C.; Iglesias Ferrer, R.; Sarabia Molina, I.

1998-01-01

This work shows basic requirements the authors think must be complied with by monitoring systems for operational surveillance based on noise analysis techniques that in turn can be employed in the regulatory control

Differential evolution algorithm based automatic generation control for interconnected power systems with

Directory of Open Access Journals (Sweden)

Banaja Mohanty

2014-09-01

Full Text Available This paper presents the design and performance analysis of Differential Evolution (DE algorithm based Proportional–Integral (PI and Proportional–Integral–Derivative (PID controllers for Automatic Generation Control (AGC of an interconnected power system. Initially, a two area thermal system with governor dead-band nonlinearity is considered for the design and analysis purpose. In the proposed approach, the design problem is formulated as an optimization problem control and DE is employed to search for optimal controller parameters. Three different objective functions are used for the design purpose. The superiority of the proposed approach has been shown by comparing the results with a recently published Craziness based Particle Swarm Optimization (CPSO technique for the same interconnected power system. It is noticed that, the dynamic performance of DE optimized PI controller is better than CPSO optimized PI controllers. Additionally, controller parameters are tuned at different loading conditions so that an adaptive gain scheduling control strategy can be employed. The study is further extended to a more realistic network of two-area six unit system with different power generating units such as thermal, hydro, wind and diesel generating units considering boiler dynamics for thermal plants, Generation Rate Constraint (GRC and Governor Dead Band (GDB non-linearity.

Probabilistic analysis on the failure of reactivity control for the PWR

Science.gov (United States)

Sony Tjahyani, D. T.; Deswandri; Sunaryo, G. R.

2018-02-01

The fundamental safety function of the power reactor is to control reactivity, to remove heat from the reactor, and to confine radioactive material. The safety analysis is used to ensure that each parameter is fulfilled during the design and is done by deterministic and probabilistic method. The analysis of reactivity control is important to be done because it will affect the other of fundamental safety functions. The purpose of this research is to determine the failure probability of the reactivity control and its failure contribution on a PWR design. The analysis is carried out by determining intermediate events, which cause the failure of reactivity control. Furthermore, the basic event is determined by deductive method using the fault tree analysis. The AP1000 is used as the object of research. The probability data of component failure or human error, which is used in the analysis, is collected from IAEA, Westinghouse, NRC and other published documents. The results show that there are six intermediate events, which can cause the failure of the reactivity control. These intermediate events are uncontrolled rod bank withdrawal at low power or full power, malfunction of boron dilution, misalignment of control rod withdrawal, malfunction of improper position of fuel assembly and ejection of control rod. The failure probability of reactivity control is 1.49E-03 per year. The causes of failures which are affected by human factor are boron dilution, misalignment of control rod withdrawal and malfunction of improper position for fuel assembly. Based on the assessment, it is concluded that the failure probability of reactivity control on the PWR is still within the IAEA criteria.

Nondeducibility-Based Analysis of Cyber-Physical Systems

Science.gov (United States)

Gamage, Thoshitha; McMillin, Bruce

Controlling information flow in a cyber-physical system (CPS) is challenging because cyber domain decisions and actions manifest themselves as visible changes in the physical domain. This paper presents a nondeducibility-based observability analysis for CPSs. In many CPSs, the capacity of a low-level (LL) observer to deduce high-level (HL) actions ranges from limited to none. However, a collaborative set of observers strategically located in a network may be able to deduce all the HL actions. This paper models a distributed power electronics control device network using a simple DC circuit in order to understand the effect of multiple observers in a CPS. The analysis reveals that the number of observers required to deduce all the HL actions in a system increases linearly with the number of configurable units. A simple definition of nondeducibility based on the uniqueness of low-level projections is also presented. This definition is used to show that a system with two security domain levels could be considered “nondeducibility secure” if no unique LL projections exist.

Observer-Based Robust Control for Hydraulic Velocity Control System

Directory of Open Access Journals (Sweden)

Wei Shen

2013-01-01

Full Text Available This paper investigates the problems of robust stabilization and robust control for the secondary component speed control system with parameters uncertainty and load disturbance. The aim is to enhance the control performance of hydraulic system based on Common Pressure Rail (CPR. Firstly, a mathematical model is presented to describe the hydraulic control system. Then a novel observer is proposed, and an observed-based control strategy is designed such that the closed-loop system is asymptotically stable and satisfies the disturbance attenuation level. The condition for the existence of the developed controller can by efficiently solved by using the MATLAB software. Finally, simulation results are provided to demonstrate the effectiveness of the proposed method.

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 ...

Rudder Based Roll Control via host-computer of A Robotic Boat

Directory of Open Access Journals (Sweden)

Xinping Bao

2009-03-01

Full Text Available Rudder based roll control of a small-sized robotic boat is a key technique for the devices on board to achieve good performance. This paper introduces a host-based robotic boat capable of performing basic movement operations. The course keeping and roll reduction are studied via rudder based method in simulations and sea trials. The boat dynamic model is built with the combination of mathematical analysis and system identification technique. A mixed sensitivity H control method design is selected since yaw and roll motion are posed in different frequency domains. Computer simulations and experiments carried out show that successful results are achieved.

Rudder Based Roll Control via Host-Computer of a Robotic Boat

Directory of Open Access Journals (Sweden)

Xinping Bao

2009-03-01

Full Text Available Rudder based roll control of a small-sized robotic boat is a key technique for the devices on board to achieve good performance. This paper introduces a host-based robotic boat capable of performing basic movement operations. The course keeping and roll reduction are studied via rudder based method in simulations and sea trials. The boat dynamic model is built with the combination of mathematical analysis and system identification technique. A mixed sensitivity H∞ control method design is selected since yaw and roll motion are posed in different frequency domains. Computer simulations and experiments carried out show that successful results are achieved.

Analysis of the Effects of Thermal Environment on Optical Systems for Navigation Guidance and Control in Supersonic Aircraft Based on Empirical Equations

Directory of Open Access Journals (Sweden)

Xuemin Cheng

2016-10-01

Full Text Available The thermal environment is an important factor in the design of optical systems. This study investigated the thermal analysis technology of optical systems for navigation guidance and control in supersonic aircraft by developing empirical equations for the front temperature gradient and rear thermal diffusion distance, and for basic factors such as flying parameters and the structure of the optical system. Finite element analysis (FEA was used to study the relationship between flying and front dome parameters and the system temperature field. Systematic deduction was then conducted based on the effects of the temperature field on the physical geometry and ray tracing performance of the front dome and rear optical lenses, by deriving the relational expressions between the system temperature field and the spot size and positioning precision of the rear optical lens. The optical systems used for navigation guidance and control in supersonic aircraft when the flight speed is in the range of 1–5 Ma were analysed using the derived equations. Using this new method it was possible to control the precision within 10% when considering the light spot received by the four-quadrant detector, and computation time was reduced compared with the traditional method of separately analysing the temperature field of the front dome and rear optical lens using FEA. Thus, the method can effectively increase the efficiency of parameter analysis and computation in an airborne optical system, facilitating the systematic, effective and integrated thermal analysis of airborne optical systems for navigation guidance and control.

Cobacabana (control of balance by card-based navigation) : A card-based system for job shop control

NARCIS (Netherlands)

Land, M.J.

Existing card-based production control systems such as Kanban are mostly dedicated to repetitive production environments. Cards-based systems for job shop control are lacking, while particularly this industry segment shows a need for simple control systems. This paper aims at filling the gap by

Analysis of Documentation Speed Using Web-Based Medical Speech Recognition Technology: Randomized Controlled Trial.

Science.gov (United States)

Vogel, Markus; Kaisers, Wolfgang; Wassmuth, Ralf; Mayatepek, Ertan

2015-11-03

Clinical documentation has undergone a change due to the usage of electronic health records. The core element is to capture clinical findings and document therapy electronically. Health care personnel spend a significant portion of their time on the computer. Alternatives to self-typing, such as speech recognition, are currently believed to increase documentation efficiency and quality, as well as satisfaction of health professionals while accomplishing clinical documentation, but few studies in this area have been published to date. This study describes the effects of using a Web-based medical speech recognition system for clinical documentation in a university hospital on (1) documentation speed, (2) document length, and (3) physician satisfaction. Reports of 28 physicians were randomized to be created with (intervention) or without (control) the assistance of a Web-based system of medical automatic speech recognition (ASR) in the German language. The documentation was entered into a browser's text area and the time to complete the documentation including all necessary corrections, correction effort, number of characters, and mood of participant were stored in a database. The underlying time comprised text entering, text correction, and finalization of the documentation event. Participants self-assessed their moods on a scale of 1-3 (1=good, 2=moderate, 3=bad). Statistical analysis was done using permutation tests. The number of clinical reports eligible for further analysis stood at 1455. Out of 1455 reports, 718 (49.35%) were assisted by ASR and 737 (50.65%) were not assisted by ASR. Average documentation speed without ASR was 173 (SD 101) characters per minute, while it was 217 (SD 120) characters per minute using ASR. The overall increase in documentation speed through Web-based ASR assistance was 26% (P=.04). Participants documented an average of 356 (SD 388) characters per report when not assisted by ASR and 649 (SD 561) characters per report when assisted

Nonlinear Disturbance Observer Based Robust Tracking Control of Pneumatic Muscle

Directory of Open Access Journals (Sweden)

Youssif Mohamed Toum Elobaid

2014-01-01

Full Text Available Presently pneumatic muscles (PMs are used in various applications due to their simple construction, lightweight, and high force-to-weight ratio. However, pneumatic muscles are facing various problems due to their nonlinear characteristics and various uncertainties in real applications. To cope with the uncertainties and strong nonlinearity of a PM model, a nonlinear disturbance observer (NDO is designed to estimate the lumped disturbance. Based on the disturbance observer, the tracking control of PM is studied. Stability analysis based on Lyapunov method with respect to our proposed control law is discussed. The simulation results show the validity, effectiveness, and enhancing robustness of the proposed methods.

Calibrating a combined energy systems analysis and controller design method with empirical data

International Nuclear Information System (INIS)

Murphy, Gavin Bruce; Counsell, John; Allison, John; Brindley, Joseph

2013-01-01

The drive towards low carbon constructions has seen buildings increasingly utilise many different energy systems simultaneously to control the human comfort of the indoor environment; such as ventilation with heat recovery, various heating solutions and applications of renewable energy. This paper describes a dynamic modelling and simulation method (IDEAS – Inverse Dynamics based Energy Assessment and Simulation) for analysing the energy utilisation of a building and its complex servicing systems. The IDEAS case study presented in this paper is based upon small perturbation theory and can be used for the analysis of the performance of complex energy systems and also for the design of smart control systems. This paper presents a process of how any dynamic model can be calibrated against a more empirical based data model, in this case the UK Government's SAP (Standard Assessment Procedure). The research targets of this work are building simulation experts for analysing the energy use of a building and also control engineers to assist in the design of smart control systems for dwellings. The calibration process presented is transferable and has applications for simulation experts to assist in calibrating any dynamic building simulation method with an empirical based method. - Highlights: • Presentation of an energy systems analysis method for assessing the energy utilisation of buildings and their complex servicing systems. • An inverse dynamics based controller design method is detailed. • Method of how a dynamic model can be calibrated with an empirical based model

Port-Based Modeling and Control for Efficient Bipedal Walking Robots

NARCIS (Netherlands)

Duindam, V.

2006-01-01

Research on walking robots has shown that the process of walking, in itself, requires little energy. Indeed, many robots have been built that walk with high efficiency. General analysis and control tools for such efficient walkers, however, are lacking, and many results are based on engineering

Speed Control Analysis of Brushless DC Motor Based on Maximum Amplitude DC Current Feedback

Directory of Open Access Journals (Sweden)

Hassan M.A.A.

2014-07-01

Full Text Available This paper describes an approach to develop accurate and simple current controlled modulation technique for brushless DC (BLDC motor drive. The approach is applied to control phase current based on generation of quasi-square wave current by using only one current controller for the three phases. Unlike the vector control method which is complicated to be implemented, this simple current modulation technique presents advantages such as phase currents are kept in balance and the current is controlled through only one dc signal which represent maximum amplitude value of trapezoidal current (Imax. This technique is performed with Proportional Integral (PI control algorithm and triangular carrier comparison method to generate Pulse Width Modulation (PWM signal. In addition, the PI speed controller is incorporated with the current controller to perform desirable speed operation of non-overshoot response. The performance and functionality of the BLDC motor driver are verified via simulation by using MATLAB/SIMULINK. The simulation results show the developed control system performs desirable speed operation of non-overshoot and good current waveforms.

No control genes required: Bayesian analysis of qRT-PCR data.

Directory of Open Access Journals (Sweden)

Mikhail V Matz

Full Text Available Model-based analysis of data from quantitative reverse-transcription PCR (qRT-PCR is potentially more powerful and versatile than traditional methods. Yet existing model-based approaches cannot properly deal with the higher sampling variances associated with low-abundant targets, nor do they provide a natural way to incorporate assumptions about the stability of control genes directly into the model-fitting process.In our method, raw qPCR data are represented as molecule counts, and described using generalized linear mixed models under Poisson-lognormal error. A Markov Chain Monte Carlo (MCMC algorithm is used to sample from the joint posterior distribution over all model parameters, thereby estimating the effects of all experimental factors on the expression of every gene. The Poisson-based model allows for the correct specification of the mean-variance relationship of the PCR amplification process, and can also glean information from instances of no amplification (zero counts. Our method is very flexible with respect to control genes: any prior knowledge about the expected degree of their stability can be directly incorporated into the model. Yet the method provides sensible answers without such assumptions, or even in the complete absence of control genes. We also present a natural Bayesian analogue of the "classic" analysis, which uses standard data pre-processing steps (logarithmic transformation and multi-gene normalization but estimates all gene expression changes jointly within a single model. The new methods are considerably more flexible and powerful than the standard delta-delta Ct analysis based on pairwise t-tests.Our methodology expands the applicability of the relative-quantification analysis protocol all the way to the lowest-abundance targets, and provides a novel opportunity to analyze qRT-PCR data without making any assumptions concerning target stability. These procedures have been implemented as the MCMC.qpcr package in R.

No control genes required: Bayesian analysis of qRT-PCR data.

Science.gov (United States)

Matz, Mikhail V; Wright, Rachel M; Scott, James G

2013-01-01

Model-based analysis of data from quantitative reverse-transcription PCR (qRT-PCR) is potentially more powerful and versatile than traditional methods. Yet existing model-based approaches cannot properly deal with the higher sampling variances associated with low-abundant targets, nor do they provide a natural way to incorporate assumptions about the stability of control genes directly into the model-fitting process. In our method, raw qPCR data are represented as molecule counts, and described using generalized linear mixed models under Poisson-lognormal error. A Markov Chain Monte Carlo (MCMC) algorithm is used to sample from the joint posterior distribution over all model parameters, thereby estimating the effects of all experimental factors on the expression of every gene. The Poisson-based model allows for the correct specification of the mean-variance relationship of the PCR amplification process, and can also glean information from instances of no amplification (zero counts). Our method is very flexible with respect to control genes: any prior knowledge about the expected degree of their stability can be directly incorporated into the model. Yet the method provides sensible answers without such assumptions, or even in the complete absence of control genes. We also present a natural Bayesian analogue of the "classic" analysis, which uses standard data pre-processing steps (logarithmic transformation and multi-gene normalization) but estimates all gene expression changes jointly within a single model. The new methods are considerably more flexible and powerful than the standard delta-delta Ct analysis based on pairwise t-tests. Our methodology expands the applicability of the relative-quantification analysis protocol all the way to the lowest-abundance targets, and provides a novel opportunity to analyze qRT-PCR data without making any assumptions concerning target stability. These procedures have been implemented as the MCMC.qpcr package in R.

Multi-flexible-body analysis for application to wind turbine control design

Science.gov (United States)

Lee, Donghoon

The objective of the present research is to build a theoretical and computational framework for the aeroelastic analysis of flexible rotating systems, more specifically with special application to a wind turbine control design. The methodology is based on the integration of Kane's approach for the analysis of the multi-rigid-body subsystem and a mixed finite element method for the analysis of the flexible-body subsystem. The combined analysis is then strongly coupled with an aerodynamic model based on Blade Element Momentum theory for inflow model. The unified framework from the analysis of subsystems is represented as, in a symbolic manner, a set of nonlinear ordinary differential equations with time-variant, periodic coefficients, which describe the aeroelastic behavior of whole system. The framework can be directly applied to control design due to its symbolic characteristics. The solution procedures for the equations are presented for the study of nonlinear simulation, periodic steady-state solution, and Floquet stability of the linearized system about the steady-state solution. Finally the linear periodic system equation can be obtained with both system and control matrices as explicit functions of time, which can be directly applicable to control design. The structural model is validated by comparison of its results with those from software, some of which is commercial. The stability of the linearized system about periodic steady-state solution is different from that obtained about a constant steady-state solution, which have been conventional in the field of wind turbine dynamics. Parametric studies are performed on a wind turbine model with various pitch angles, precone angles, and rotor speeds. Combined with composite material, their effects on wind turbine aeroelastic stability are investigated. Finally it is suggested that the aeroelastic stability analysis and control design for the whole system is crucial for the design of wind turbines, and the

Interactive Controls Analysis (INCA)

Science.gov (United States)

Bauer, Frank H.

1989-01-01

Version 3.12 of INCA provides user-friendly environment for design and analysis of linear control systems. System configuration and parameters easily adjusted, enabling INCA user to create compensation networks and perform sensitivity analysis in convenient manner. Full complement of graphical routines makes output easy to understand. Written in Pascal and FORTRAN.

Formal Design and Analysis of a Wastewater Treatment Control System based on Petrinet

Directory of Open Access Journals (Sweden)

Seno D. Panjaitan

2012-04-01

Full Text Available This paper proposes a new control design approach for industrial wastewater treatment where its logic control is verifiable. In this research, a treatment control design in a lab-scale was controlled by a microcontroller circuit. The developed system combined anaerobic digestion, aeration and filtration process. Its logic control algorithm was designed by using Signal Interpreted Petri Net. In the logic verification, six analysis properties were satisfied: conflict free (logical process had no conflict behavior, termination (the process could be terminated from any state, non-contradictory outputs, live (any process state could always be reached from other state, deadlock-free, and reversible (the process could always back to initial condition. In the design evaluation, the average value of transparency metrics was 0.984 close to 1 as the best value. The system performance was evaluated by pollutant removal efficiency. The highest removal efficiencies were obtained when each anaerobic and aeration treatment were performed for three days respectively and followed by filtration. Within this condition, the system obtained average removal efficiency 91.7% of Chemical Oxygen Demand and 95.4% of Total Suspended Solids. In terms of electricity consumption, the system needed only 1,857.6 Watt-hour for a batch treatment process.

Improving the Critic Learning for Event-Based Nonlinear $H_{\\infty }$ Control Design.

Science.gov (United States)

Wang, Ding; He, Haibo; Liu, Derong

2017-10-01

In this paper, we aim at improving the critic learning criterion to cope with the event-based nonlinear H ∞ state feedback control design. First of all, the H ∞ control problem is regarded as a two-player zero-sum game and the adaptive critic mechanism is used to achieve the minimax optimization under event-based environment. Then, based on an improved updating rule, the event-based optimal control law and the time-based worst-case disturbance law are obtained approximately by training a single critic neural network. The initial stabilizing control is no longer required during the implementation process of the new algorithm. Next, the closed-loop system is formulated as an impulsive model and its stability issue is handled by incorporating the improved learning criterion. The infamous Zeno behavior of the present event-based design is also avoided through theoretical analysis on the lower bound of the minimal intersample time. Finally, the applications to an aircraft dynamics and a robot arm plant are carried out to verify the efficient performance of the present novel design method.

Determining the energy performance of manually controlled solar shades: A stochastic model based co-simulation analysis

International Nuclear Information System (INIS)

Yao, Jian

2014-01-01

Highlights: • Driving factor for adjustment of manually controlled solar shades was determined. • A stochastic model for manual solar shades was constructed using Markov method. • Co-simulation with Energyplus was carried out in BCVTB. • External shading even manually controlled should be used prior to LOW-E windows. • Previous studies on manual solar shades may overestimate energy savings. - Abstract: Solar shading devices play a significant role in reducing building energy consumption and maintaining a comfortable indoor condition. In this paper, a typical office building with internal roller shades in hot summer and cold winter zone was selected to determine the driving factor of control behavior of manual solar shades. Solar radiation was determined as the major factor in driving solar shading adjustment based on field measurements and logit analysis and then a stochastic model for manually adjusted solar shades was constructed by using Markov method. This model was used in BCVTB for further co-simulation with Energyplus to determine the impact of the control behavior of solar shades on energy performance. The results show that manually adjusted solar shades, whatever located inside or outside, have a relatively high energy saving performance than clear-pane windows while only external shades perform better than regularly used LOW-E windows. Simulation also indicates that using an ideal assumption of solar shade adjustment as most studies do in building simulation may lead to an overestimation of energy saving by about 16–30%. There is a need to improve occupants’ actions on shades to more effectively respond to outdoor conditions in order to lower energy consumption, and this improvement can be easily achieved by using simple strategies as a guide to control manual solar shades

Quality control analysis at the hospital

International Nuclear Information System (INIS)

Kristensen, K.

1979-01-01

Quality control analysis is an integral part of quality assurance. In a system as with radiopharmaceuticals where part of the finishing of the product takes place at individual hospitals, the need for quality control analysis at the hospital can be discussed. Data are presented that stresses the importance of quality control by the manufacturer as a basis for limitation of such work at hospitals. A simplified programme is proposed

Effect of boundary on controlled memristor-based oscillator

KAUST Repository

Fouda, Mohamed E.

2012-10-01

Recently, the applications of memristors have spread into many fields and especially in the circuit theory. Many models have been proposed for the HP-memristor based on the window functions. In this paper, we introduce a complete mathematical analysis of the controlled reactance-less oscillator for two different window functions of Joglekar\\'s model (linear and nonlinear dopant drift) to discuss the effect of changing the window function on the oscillator\\'s behavior. The generalized necessary and sufficient conditions based on the circuit elements and control voltages for both the linear and nonlinear models are introduced. Moreover, closed form expressions for the oscillation frequency and duty cycle are derived for these models and verified using PSPICE simulations showing an excellent matching. Finally a comparison between the linear and nonlinear models which shows their effect on the oscillation frequency and conditions of oscillation is introduced. © 2012 IEEE.

Modeling and sensitivity analysis of consensus algorithm based distributed hierarchical control for dc microgrids

DEFF Research Database (Denmark)

Meng, Lexuan; Dragicevic, Tomislav; Vasquez, Juan Carlos

2015-01-01

of dynamic study. The aim of this paper is to model the complete DC microgrid system in z-domain and perform sensitivity analysis for the complete system. A generalized modeling method is proposed and the system dynamics under different control parameters, communication topologies and communication speed...

Nuclear power plant control room task analysis. Pilot study for pressurized water reactors

International Nuclear Information System (INIS)

Barks, D.B.; Kozinsky, E.J.; Eckel, S.

1982-05-01

The purposes of this nuclear plant task analysis pilot study: to demonstrate the use of task analysis techniques on selected abnormal or emergency operation events in a nuclear power plant; to evaluate the use of simulator data obtained from an automated Performance Measurement System to supplement and validate data obtained by traditional task analysis methods; and to demonstrate sample applications of task analysis data to address questions pertinent to nuclear power plant operational safety: control room layout, staffing and training requirements, operating procedures, interpersonal communications, and job performance aids. Five data sources were investigated to provide information for a task analysis. These sources were (1) written operating procedures (event-based); (2) interviews with subject matter experts (the control room operators); (3) videotapes of the control room operators (senior reactor operators and reactor operators) while responding to each event in a simulator; (4) walk-/talk-throughs conducted by control room operators for each event; and (5) simulator data from the PMS

Model based design of electronic throttle control

Science.gov (United States)

Cherian, Fenin; Ranjan, Ashish; Bhowmick, Pathikrit; Rammohan, A.

2017-11-01

With the advent of torque based Engine Management Systems, the precise control and robust performance of the throttle body becomes a key factor in the overall performance of the vehicle. Electronic Throttle Control provides benefits such as improved air-fuel ratio for improving the vehicle performance and lower exhausts emissions to meet the stringent emission norms. Modern vehicles facilitate various features such as Cruise Control, Traction Control, Electronic Stability Program and Pre-crash systems. These systems require control over engine power without driver intervention, which is not possible with conventional mechanical throttle system. Thus these systems are integrated to function with the electronic throttle control. However, due to inherent non-linearities in the throttle body, the control becomes a difficult task. In order to eliminate the influence of this hysteresis at the initial operation of the butterfly valve, a control to compensate the shortage must be added to the duty required for starting throttle operation when the initial operation is detected. Therefore, a lot of work is being done in this field to incorporate the various nonlinearities to achieve robust control. In our present work, the ETB was tested to verify the working of the system. Calibration of the TPS sensors was carried out in order to acquire accurate throttle opening angle. The response of the calibrated system was then plotted against a step input signal. A linear model of the ETB was prepared using Simulink and its response was compared with the experimental data to find out the initial deviation of the model from the actual system. To reduce this deviation, non-linearities from existing literature were introduced to the system and a response analysis was performed to check the deviation from the actual system. Based on this investigation, an introduction of a new nonlinearity parameter can be used in future to reduce the deviation further making the control of the ETB more

Modular Control Flow Analysis for Libraries

DEFF Research Database (Denmark)

Probst, Christian W.

2002-01-01

One problem in analyzing object oriented languages is that the exact control flow graph is not known statically due to dynamic dispatching. However, this is needed in order to apply the large class of known interprocedural analysis. Control Flow Analysis in the object oriented setting aims...

Design and performance analysis of position-based impedance control for an electrohydrostatic actuation system

Directory of Open Access Journals (Sweden)

Yongling FU

2018-03-01

Full Text Available Electrohydrostatic actuator (EHA is a type of power-by-wire actuator that is widely implemented in the aerospace industry for flight control, landing gears, thrust reversers, thrust vector control, and space robots. This paper presents the development and evaluation of position-based impedance control (PBIC for an EHA. Impedance control provides the actuator with compliance and facilitates the interaction with the environment. Most impedance control applications utilize electrical or valve-controlled hydraulic actuators, whereas this work realizes impedance control via a compact and efficient EHA. The structures of the EHA and PBIC are firstly introduced. A mathematical model of the actuation system is established, and values of its coefficients are identified by particle swarm optimization. This model facilitates the development of a position controller and the selection of target impedance parameters. A nonlinear proportional-integral position controller is developed for the EHA to achieve the accurate positioning requirement of PBIC. The controller compensates for the adverse effect of stiction, and a position accuracy of 0.08 mm is attained. Various experimental results are presented to verify the applicability of PBIC to the EHA. The compliance of the actuator is demonstrated in an impact test. Keywords: Actuation system, Aerospace, Electrohydrostatic actuator, Force control, Nonlinear dynamics, Particle swarm optimization, Position control

Control system for technological processes in tritium processing plants with process analysis

International Nuclear Information System (INIS)

Retevoi, Carmen Maria; Stefan, Iuliana; Balteanu, Ovidiu; Stefan, Liviu; Bucur, Ciprian

2005-01-01

Integration of a large variety of installations and equipment into a unitary system for controlling the technological process in tritium processing nuclear facilities appears to be a rather complex approach particularly when experimental or new technologies are developed. Ensuring a high degree of versatility allowing easy modifications in configurations and process parameters is a major requirement imposed on experimental installations. The large amount of data which must be processed, stored and easily accessed for subsequent analyses imposes development of a large information network based on a highly integrated system containing the acquisition, control and technological process analysis data as well as data base system. On such a basis integrated systems of computation and control able to conduct the technological process could be developed as well protection systems for cases of failures or break down. The integrated system responds to the control and security requirements in case of emergency and of the technological processes specific to the industry that processes radioactive or toxic substances with severe consequences in case of technological failure as in the case of tritium processing nuclear plant. In order to lower the risk technological failure of these processes an integrated software, data base and process analysis system are developed, which, based on identification algorithm of the important parameters for protection and security systems, will display the process evolution trend. The system was checked on a existing plant that includes a removal tritium unit, finally used in a nuclear power plant, by simulating the failure events as well as the process. The system will also include a complete data base monitoring all the parameters and a process analysis software for the main modules of the tritium processing plant, namely, isotope separation, catalytic purification and cryogenic distillation

Optimisation-based worst-case analysis and anti-windup synthesis for uncertain nonlinear systems

Science.gov (United States)

Menon, Prathyush Purushothama

This thesis describes the development and application of optimisation-based methods for worst-case analysis and anti-windup synthesis for uncertain nonlinear systems. The worst-case analysis methods developed in the thesis are applied to the problem of nonlinear flight control law clearance for highly augmented aircraft. Local, global and hybrid optimisation algorithms are employed to evaluate worst-case violations of a nonlinear response clearance criterion, for a highly realistic aircraft simulation model and flight control law. The reliability and computational overheads associated with different opti misation algorithms are compared, and the capability of optimisation-based approaches to clear flight control laws over continuous regions of the flight envelope is demonstrated. An optimisation-based method for computing worst-case pilot inputs is also developed, and compared with current industrial approaches for this problem. The importance of explicitly considering uncertainty in aircraft parameters when computing worst-case pilot demands is clearly demonstrated. Preliminary results on extending the proposed framework to the problems of limit-cycle analysis and robustness analysis in the pres ence of time-varying uncertainties are also included. A new method for the design of anti-windup compensators for nonlinear constrained systems controlled using nonlinear dynamics inversion control schemes is presented and successfully applied to some simple examples. An algorithm based on the use of global optimisation is proposed to design the anti-windup compensator. Some conclusions are drawn from the results of the research presented in the thesis, and directions for future work are identified.

Noise filtering algorithm for the MFTF-B computer based control system

International Nuclear Information System (INIS)

Minor, E.G.

1983-01-01

An algorithm to reduce the message traffic in the MFTF-B computer based control system is described. The algorithm filters analog inputs to the control system. Its purpose is to distinguish between changes in the inputs due to noise and changes due to significant variations in the quantity being monitored. Noise is rejected while significant changes are reported to the control system data base, thus keeping the data base updated with a minimum number of messages. The algorithm is memory efficient, requiring only four bytes of storage per analog channel, and computationally simple, requiring only subtraction and comparison. Quantitative analysis of the algorithm is presented for the case of additive Gaussian noise. It is shown that the algorithm is stable and tends toward the mean value of the monitored variable over a wide variety of additive noise distributions

Active vibration control based on piezoelectric smart composite

International Nuclear Information System (INIS)

Gao, Le; Lu, Qingqing; Fei, Fan; Leng, Jinsong; Liu, Liwu; Liu, Yanju

2013-01-01

An aircraft’s vertical fin may experience dramatic buffet loads in high angle of attack flight conditions, and these buffet loads would cause huge vibration and dynamic stress on the vertical fin structure. To reduce the dynamic vibration of the vertical fin structure, macro fiber composite (MFC) actuators were used in this paper. The drive moment equations and sensing voltage equations of the MFC actuators were developed. Finite element analysis models based on three kinds of models of simplified vertical fin structures with surface-bonded MFC actuators were established in ABAQUS. The equivalent damping ratio of the structure was employed in finite element analysis, in order to measure the effectiveness of vibration control. Further, an open-loop test for the active vibration control system of the vertical fin with MFC actuators was designed and developed. The experimental results validated the effectiveness of the MFC actuators as well as the developed methodology. (paper)

Improved Polynomial Fuzzy Modeling and Controller with Stability Analysis for Nonlinear Dynamical Systems

Directory of Open Access Journals (Sweden)

Hamed Kharrati

2012-01-01

Full Text Available This study presents an improved model and controller for nonlinear plants using polynomial fuzzy model-based (FMB systems. To minimize mismatch between the polynomial fuzzy model and nonlinear plant, the suitable parameters of membership functions are determined in a systematic way. Defining an appropriate fitness function and utilizing Taylor series expansion, a genetic algorithm (GA is used to form the shape of membership functions in polynomial forms, which are afterwards used in fuzzy modeling. To validate the model, a controller based on proposed polynomial fuzzy systems is designed and then applied to both original nonlinear plant and fuzzy model for comparison. Additionally, stability analysis for the proposed polynomial FMB control system is investigated employing Lyapunov theory and a sum of squares (SOS approach. Moreover, the form of the membership functions is considered in stability analysis. The SOS-based stability conditions are attained using SOSTOOLS. Simulation results are also given to demonstrate the effectiveness of the proposed method.

Efficacy of home-based non-pharmacological interventions for treating depression: a systematic review and network meta-analysis of randomised controlled trials.

Science.gov (United States)

Sukhato, Kanokporn; Lotrakul, Manote; Dellow, Alan; Ittasakul, Pichai; Thakkinstian, Ammarin; Anothaisintawee, Thunyarat

2017-07-12

To systematically review and compare the efficacy of all available home-based non-pharmacological treatments of depression. Systematic review and network meta-analysis of randomised controlled trials. Medline, Scopus and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases were searched since inceptions to 7 August 2016. Randomised controlled trials comparing the efficacy of home-based non-pharmacological interventions with usual care of patients with depression were included in the review. Depression symptom scores and disease remission rates at the end of treatment. Seventeen studies were included in the review. Home-based non-pharmacological interventions were categorised as (1) home-based psychological intervention, (2) home-based exercise intervention, (3) combined home-based psychological intervention with exercise intervention and (4) complementary medicine. Complementary medicine approaches were excluded from the meta-analysis due to heterogeneity. The standardised mean differences of post-treatment depression symptom scores between usual care groups and home-based psychological intervention, home-based exercise intervention and combined home-based psychological intervention with exercise intervention were âˆ'0.57 (95% CI âˆ'0.84 to âˆ'0.31), âˆ'1.03 (95% CI âˆ'2.89 to 0.82) and âˆ'0.78 (95% CI âˆ'1.09 to âˆ'0.47), respectively. These results suggest that only home-based psychological intervention and combined home-based psychological intervention with exercise intervention could significantly decrease depression scores. Compared with usual care groups, the disease remission rate was also significantly higher for home-based psychological intervention (pooled risk ratio=1.53; 95% CI 1.19 to 1.98) and combined home-based psychological intervention with exercise intervention (pooled risk ratio=3.47; 95% CI 2.11 to 5.70). Of all the studied interventions, combined home-based psychological intervention with

Simulation-based biagnostics and control for nuclar power plants

International Nuclear Information System (INIS)

Lee, J.C.

1993-01-01

Advanced simulation-based diagnostics and control guidance systems for the identification and management of off-normal transient events in nuclear power plants is currently under investigation. To date a great deal of progress has been made in effectively and efficiently combining information obtained through fuzzy pattern recognition and macroscopic mass and energy inventory analysis for use in multiple failure diagnostics. Work has also begun on the unique problem of diagnostics and surveillance methodologies for advanced passively-safe reactors systems utilizing both statistical and fuzzy information. Plans are also being formulated for the development of deterministic optimal control algorithms combined with Monte Carlo incremental learning algorithms to be used for the flexible and efficient control of reactor transients

Quality control of the analysis of IAEA samples in the radium institute

International Nuclear Information System (INIS)

Belyaev, B.N.; Lovtsus, A.V.; Makarova, T.P.; Stepanov, A.V.

1989-01-01

Metrological chracteristics of mass and alpha spectrometric methods in the Radium Institute for analysis of spent fuel control samples are evaluated. The techniques of analysis and the procedure of quality control for isotopic ratio measurements based on the use of uranium and plutonium standard reference materials (NBS, NBL, SAL made in USSR) are described. The results of measurements performed during cooperation with IAEA are discussed, and the sources of systematic and random errors are analyzed. The results obtained agree well with the target values. (author)

Coordinate based random effect size meta-analysis of neuroimaging studies.

Science.gov (United States)

Tench, C R; Tanasescu, Radu; Constantinescu, C S; Auer, D P; Cottam, W J

2017-06-01

Low power in neuroimaging studies can make them difficult to interpret, and Coordinate based meta-analysis (CBMA) may go some way to mitigating this issue. CBMA has been used in many analyses to detect where published functional MRI or voxel-based morphometry studies testing similar hypotheses report significant summary results (coordinates) consistently. Only the reported coordinates and possibly t statistics are analysed, and statistical significance of clusters is determined by coordinate density. Here a method of performing coordinate based random effect size meta-analysis and meta-regression is introduced. The algorithm (ClusterZ) analyses both coordinates and reported t statistic or Z score, standardised by the number of subjects. Statistical significance is determined not by coordinate density, but by a random effects meta-analyses of reported effects performed cluster-wise using standard statistical methods and taking account of censoring inherent in the published summary results. Type 1 error control is achieved using the false cluster discovery rate (FCDR), which is based on the false discovery rate. This controls both the family wise error rate under the null hypothesis that coordinates are randomly drawn from a standard stereotaxic space, and the proportion of significant clusters that are expected under the null. Such control is necessary to avoid propagating and even amplifying the very issues motivating the meta-analysis in the first place. ClusterZ is demonstrated on both numerically simulated data and on real data from reports of grey matter loss in multiple sclerosis (MS) and syndromes suggestive of MS, and of painful stimulus in healthy controls. The software implementation is available to download and use freely. Copyright © 2017 Elsevier Inc. All rights reserved.

Correlation of a hypoxia based tumor control model with observed local control rates in nasopharyngeal carcinoma treated with chemoradiotherapy

Energy Technology Data Exchange (ETDEWEB)

Avanzo, Michele; Stancanello, Joseph; Franchin, Giovanni; Sartor, Giovanna; Jena, Rajesh; Drigo, Annalisa; Dassie, Andrea; Gigante, Marco; Capra, Elvira [Department of Medical Physics, Centro di Riferimento Oncologico, Aviano 33081 (Italy); Research and Clinical Collaborations, Siemens Healthcare, Erlangen 91052 (Germany); Department of Radiation Oncology, Centro di Riferimento Oncologico, Aviano 33081 (Italy); Department of Medical Physics, Centro di Riferimento Oncologico, Aviano 33081 (Italy); Oncology Centre, Cambridge University Hospitals NHS Foundation Trust, Cambridge CB2 0QQ (United Kingdom); Department of Medical Physics, Centro di Riferimento Oncologico, Aviano 33081 (Italy); Department of Radiation Oncology, Centro di Riferimento Oncologico, Aviano 33081 (Italy); Department of Medical Physics, Centro di Riferimento Oncologico, Aviano 33081 (Italy)

2010-04-15

Purpose: To extend the application of current radiation therapy (RT) based tumor control probability (TCP) models of nasopharyngeal carcinoma (NPC) to include the effects of hypoxia and chemoradiotherapy (CRT). Methods: A TCP model is described based on the linear-quadratic model modified to account for repopulation, chemotherapy, heterogeneity of dose to the tumor, and hypoxia. Sensitivity analysis was performed to determine which parameters exert the greatest influence on the uncertainty of modeled TCP. On the basis of the sensitivity analysis, the values of specific radiobiological parameters were set to nominal values reported in the literature for NPC or head and neck tumors. The remaining radiobiological parameters were determined by fitting TCP to clinical local control data from published randomized studies using both RT and CRT. Validation of the model was performed by comparison of estimated TCP and average overall local control rate (LCR) for 45 patients treated at the institution with conventional linear-accelerator-based or helical tomotherapy based intensity-modulated RT and neoadjuvant chemotherapy. Results: Sensitivity analysis demonstrates that the model is most sensitive to the radiosensitivity term {alpha} and the dose per fraction. The estimated values of {alpha} and OER from data fitting were 0.396 Gy{sup -1} and 1.417. The model estimate of TCP (average 90.9%, range 26.9%-99.2%) showed good correlation with the LCR (86.7%). Conclusions: The model implemented in this work provides clinicians with a useful tool to predict the success rate of treatment, optimize treatment plans, and compare the effects of multimodality therapy.

Correlation of a hypoxia based tumor control model with observed local control rates in nasopharyngeal carcinoma treated with chemoradiotherapy

International Nuclear Information System (INIS)

Avanzo, Michele; Stancanello, Joseph; Franchin, Giovanni; Sartor, Giovanna; Jena, Rajesh; Drigo, Annalisa; Dassie, Andrea; Gigante, Marco; Capra, Elvira

2010-01-01

Purpose: To extend the application of current radiation therapy (RT) based tumor control probability (TCP) models of nasopharyngeal carcinoma (NPC) to include the effects of hypoxia and chemoradiotherapy (CRT). Methods: A TCP model is described based on the linear-quadratic model modified to account for repopulation, chemotherapy, heterogeneity of dose to the tumor, and hypoxia. Sensitivity analysis was performed to determine which parameters exert the greatest influence on the uncertainty of modeled TCP. On the basis of the sensitivity analysis, the values of specific radiobiological parameters were set to nominal values reported in the literature for NPC or head and neck tumors. The remaining radiobiological parameters were determined by fitting TCP to clinical local control data from published randomized studies using both RT and CRT. Validation of the model was performed by comparison of estimated TCP and average overall local control rate (LCR) for 45 patients treated at the institution with conventional linear-accelerator-based or helical tomotherapy based intensity-modulated RT and neoadjuvant chemotherapy. Results: Sensitivity analysis demonstrates that the model is most sensitive to the radiosensitivity term α and the dose per fraction. The estimated values of α and OER from data fitting were 0.396 Gy -1 and 1.417. The model estimate of TCP (average 90.9%, range 26.9%-99.2%) showed good correlation with the LCR (86.7%). Conclusions: The model implemented in this work provides clinicians with a useful tool to predict the success rate of treatment, optimize treatment plans, and compare the effects of multimodality therapy.

Component-based analysis of embedded control applications

DEFF Research Database (Denmark)

Angelov, Christo K.; Guan, Wei; Marian, Nicolae

2011-01-01

instances of reusable, executable components—function blocks (FBs). System actors operate in accordance with a timed multitasking model of computation, whereby I/O signals are exchanged with the controlled plant at precisely specified time instants, resulting in the elimination of I/O jitter. The paper...

Modeling, analysis, and design of stationary reference frame droop controlled parallel three-phase voltage source inverters

DEFF Research Database (Denmark)

Vasquez, Juan Carlos; Guerrero, Josep M.; Savaghebi, Mehdi

2013-01-01

Power electronics based MicroGrids consist of a number of voltage source inverters (VSIs) operating in parallel. In this paper, the modeling, control design, and stability analysis of parallel connected three-phase VSIs are derived. The proposed voltage and current inner control loops and the mat......Power electronics based MicroGrids consist of a number of voltage source inverters (VSIs) operating in parallel. In this paper, the modeling, control design, and stability analysis of parallel connected three-phase VSIs are derived. The proposed voltage and current inner control loops...... control restores the frequency and amplitude deviations produced by the primary control. Also, a synchronization algorithm is presented in order to connect the MicroGrid to the grid. Experimental results are provided to validate the performance and robustness of the parallel VSI system control...

Feasibility analysis of fuzzy logic control for ITER Poloidal field (PF) AC/DC converter system

Energy Technology Data Exchange (ETDEWEB)

Hassan, Mahmood Ul; Fu, Peng [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China (China); Song, Zhiquan, E-mail: zhquansong@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Chen, Xiaojiao [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China (China); Zhang, Xiuqing [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Humayun, Muhammad [Shanghai Jiaotong University (China)

2017-05-15

Highlights: • The implementation of the Fuzzy controller for the ITER PF converter system is presented. • The comparison of the FLC and PI simulation are investigated. • The FLC single and parallel bridge operation are presented. • Fuzzification and Defuzzification algorithms are presented using FLC controller. - Abstract: This paper describes the feasibility analysis of the fuzzy logic control to increase the performance of the ITER poloidal field (PF) converter systems. A fuzzy-logic-based controller is designed for ITER PF converter system, using the traditional PI controller and Fuzzy controller (FC), the dynamic behavior and transient response of the PF converter system are compared under normal operation by analysis and simulation. The analysis results show that the fuzzy logic control can achieve better operation performance than PI control.

Observer-based linear parameter varying H∞ tracking control for hypersonic vehicles

Directory of Open Access Journals (Sweden)

Yiqing Huang

2016-11-01

Full Text Available This article aims to develop observer-based linear parameter varying output feedback H∞ tracking controller for hypersonic vehicles. Due to the complexity of an original nonlinear model of the hypersonic vehicle dynamics, a slow–fast loop linear parameter varying polytopic model is introduced for system stability analysis and controller design. Then, a state observer is developed by linear parameter varying technique in order to estimate the unmeasured attitude angular for slow loop system. Also, based on the designed linear parameter varying state observer, a kind of attitude tracking controller is presented to reduce tracking errors for all bounded reference attitude angular inputs. The closed-loop linear parameter varying system is proved to be quadratically stable by Lypapunov function technique. Finally, simulation results show that the developed linear parameter varying H∞ controller has good tracking capability for reference commands.

Predicting successful treatment outcome of web-based self-help for problem drinkers: secondary analysis from a randomized controlled trial.

Science.gov (United States)

Riper, Heleen; Kramer, Jeannet; Keuken, Max; Smit, Filip; Schippers, Gerard; Cuijpers, Pim

2008-11-22

Web-based self-help interventions for problem drinking are coming of age. They have shown promising results in terms of cost-effectiveness, and they offer opportunities to reach out on a broad scale to problem drinkers. The question now is whether certain groups of problem drinkers benefit more from such Web-based interventions than others. We sought to identify baseline, client-related predictors of the effectiveness of Drinking Less, a 24/7, free-access, interactive, Web-based self-help intervention without therapist guidance for problem drinkers who want to reduce their alcohol consumption. The intervention is based on cognitive-behavioral and self-control principles. We conducted secondary analysis of data from a pragmatic randomized trial with follow-up at 6 and 12 months. Participants (N = 261) were adult problem drinkers in the Dutch general population with a weekly alcohol consumption above 210 g of ethanol for men or 140 g for women, or consumption of at least 60 g (men) or 40 g (women) one or more days a week over the past 3 months. Six baseline participant characteristics were designated as putative predictors of treatment response: (1) gender, (2) education, (3) Internet use competence (sociodemographics), (4) mean weekly alcohol consumption, (5) prior professional help for alcohol problems (level of problem drinking), and (6) participants' expectancies of Web-based interventions for problem drinking. Intention-to-treat (ITT) analyses, using last-observation-carried-forward (LOCF) data, and regression imputation (RI) were performed to deal with loss to follow-up. Statistical tests for interaction terms were conducted and linear regression analysis was performed to investigate whether the participants' characteristics as measured at baseline predicted positive treatment responses at 6- and 12-month follow-ups. At 6 months, prior help for alcohol problems predicted a small, marginally significant positive treatment outcome in the RI model only (beta = .18

On Cyber Attacks and Signature Based Intrusion Detection for MODBUS Based Industrial Control Systems

Directory of Open Access Journals (Sweden)

Wei Gao

2014-03-01

Full Text Available Industrial control system communication networks are vulnerable to reconnaissance, response injection, command injection, and denial of service attacks.  Such attacks can lead to an inability to monitor and control industrial control systems and can ultimately lead to system failure. This can result in financial loss for control system operators and economic and safety issues for the citizens who use these services.  This paper describes a set of 28 cyber attacks against industrial control systems which use the MODBUS application layer network protocol. The paper also describes a set of standalone and state based intrusion detection system rules which can be used to detect cyber attacks and to store evidence of attacks for post incident analysis. All attacks described in this paper were validated in a laboratory environment. The detection rate of the intrusion detection system rules presented by attack class is also presented.

Decentralized control using compositional analysis techniques

NARCIS (Netherlands)

Kerber, F.; van der Schaft, A. J.

2011-01-01

Decentralized control strategies aim at achieving a global control target by means of distributed local controllers acting on individual subsystems of the overall plant. In this sense, decentralized control is a dual problem to compositional analysis where a global verification task is decomposed

Demand Management Based on Model Predictive Control Techniques

Directory of Open Access Journals (Sweden)

Yasser A. Davizón

2014-01-01

Full Text Available Demand management (DM is the process that helps companies to sell the right product to the right customer, at the right time, and for the right price. Therefore the challenge for any company is to determine how much to sell, at what price, and to which market segment while maximizing its profits. DM also helps managers efficiently allocate undifferentiated units of capacity to the available demand with the goal of maximizing revenue. This paper introduces control system approach to demand management with dynamic pricing (DP using the model predictive control (MPC technique. In addition, we present a proper dynamical system analogy based on active suspension and a stability analysis is provided via the Lyapunov direct method.

Reinforcement Learning for Ramp Control: An Analysis of Learning Parameters

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Chao Lu

2016-08-01

Full Text Available Reinforcement Learning (RL has been proposed to deal with ramp control problems under dynamic traffic conditions; however, there is a lack of sufficient research on the behaviour and impacts of different learning parameters. This paper describes a ramp control agent based on the RL mechanism and thoroughly analyzed the influence of three learning parameters; namely, learning rate, discount rate and action selection parameter on the algorithm performance. Two indices for the learning speed and convergence stability were used to measure the algorithm performance, based on which a series of simulation-based experiments were designed and conducted by using a macroscopic traffic flow model. Simulation results showed that, compared with the discount rate, the learning rate and action selection parameter made more remarkable impacts on the algorithm performance. Based on the analysis, some suggestionsabout how to select suitable parameter values that can achieve a superior performance were provided.

Stability analysis of DC microgrids with constant power load under distributed control methods

DEFF Research Database (Denmark)

Liu, Zhangjie; Su, Mei; Sun, Yao

2018-01-01

of distributed controller is investigated. The small-signal model is established to predict the system qualitative behavior around equilibrium. The stability conditions of the system with time delay are derived based on the equivalent linearized model. Additionally, eigenvalue analysis based on inertia theorem...

A magnetorheological fluid-based multifunctional haptic device for vehicular instrument controls

International Nuclear Information System (INIS)

Han, Young-Min; Kim, Chan-Jung; Choi, Seung-Bok

2009-01-01

This paper presents control performances of a magnetorheological (MR) fluid-based multifunctional haptic device which is applicable to vehicular instrument controls. By combining in-vehicle functions into a single device, the proposed haptic device can transmit various reflection forces for each comfort function to a driver without requiring the driver's visual attention. As a multifunctional haptic device, a MR knob is proposed in this work and then devised to be capable of both rotary and push motions with a single knob. Under consideration of the spatial limitations of vehicle dashboards, design parameters are optimally determined by finite element analysis, and the objective function is to maximize a relative control torque. The proposed haptic device is then manufactured, and in-vehicle comfort functions are constructed in a virtual environment which makes the functions to communicate with the haptic device. Subsequently, a feed-forward controller using torque/force maps is formulated for the force tracking control. Control performances such as reflection force of the haptic device are experimentally evaluated via the torque/force map-based feed-forward controller

ASTEC: Controls analysis for personal computers

Science.gov (United States)

Downing, John P.; Bauer, Frank H.; Thorpe, Christopher J.

1989-01-01

The ASTEC (Analysis and Simulation Tools for Engineering Controls) software is under development at Goddard Space Flight Center (GSFC). The design goal is to provide a wide selection of controls analysis tools at the personal computer level, as well as the capability to upload compute-intensive jobs to a mainframe or supercomputer. The project is a follow-on to the INCA (INteractive Controls Analysis) program that has been developed at GSFC over the past five years. While ASTEC makes use of the algorithms and expertise developed for the INCA program, the user interface was redesigned to take advantage of the capabilities of the personal computer. The design philosophy and the current capabilities of the ASTEC software are described.

A VME based cryogenic data acquisition and control system (CRYO-DACS)

International Nuclear Information System (INIS)

Antony, Joby; Rajkumar; Datta, T.S.

2005-01-01

This report describes a newly developed VME based data acquisition and control system named CRYO-DACS for acquiring and controlling various analog and digital cryogenic parameters from equipment's like beam-line cryostats, Helium compressors, liquefier, cryogenic distribution line etc. A new central control room has been set-up for the remote controls and monitoring. The system monitors various analog parameters like temperature, pressure, vacuum and cryogenic fluid levels inside the cryostats and performs closed loop controls of cryogen valves. The hardware architecture of CRYO-DACS is multi-crate distributed VME, all linked by workstation clients in 100 Mb/s LAN for distributed logging, historical trending, analysis, alarm management and control GUIs. (author)

On the Analysis of Case-Control Studies in Cluster-correlated Data Settings.

Science.gov (United States)

Haneuse, Sebastien; Rivera-Rodriguez, Claudia

2018-01-01

In resource-limited settings, long-term evaluation of national antiretroviral treatment (ART) programs often relies on aggregated data, the analysis of which may be subject to ecological bias. As researchers and policy makers consider evaluating individual-level outcomes such as treatment adherence or mortality, the well-known case-control design is appealing in that it provides efficiency gains over random sampling. In the context that motivates this article, valid estimation and inference requires acknowledging any clustering, although, to our knowledge, no statistical methods have been published for the analysis of case-control data for which the underlying population exhibits clustering. Furthermore, in the specific context of an ongoing collaboration in Malawi, rather than performing case-control sampling across all clinics, case-control sampling within clinics has been suggested as a more practical strategy. To our knowledge, although similar outcome-dependent sampling schemes have been described in the literature, a case-control design specific to correlated data settings is new. In this article, we describe this design, discuss balanced versus unbalanced sampling techniques, and provide a general approach to analyzing case-control studies in cluster-correlated settings based on inverse probability-weighted generalized estimating equations. Inference is based on a robust sandwich estimator with correlation parameters estimated to ensure appropriate accounting of the outcome-dependent sampling scheme. We conduct comprehensive simulations, based in part on real data on a sample of N = 78,155 program registrants in Malawi between 2005 and 2007, to evaluate small-sample operating characteristics and potential trade-offs associated with standard case-control sampling or when case-control sampling is performed within clusters.

Analysis and control of a parallel lower limb based on pneumatic artificial muscles

Directory of Open Access Journals (Sweden)

Feilong Jiang

2016-12-01

Full Text Available Most robots that are actuated by antagonistic pneumatic artificial muscles are controlled by various control algorithms that cannot adequately imitate the actual muscle distribution of human limbs. Other robots in which the distribution of pneumatic artificial muscle is similar to that of human limbs can only analyze the position of the robot using perceptual data instead of rational knowledge. In order to better imitate the movement of a human limb, the article proposes a humanoid lower limb in the form of a parallel mechanism where muscle is unevenly distributed. Next, the kinematic and dynamic movements of bionic hip joint are analyzed, where the joint movement is controlled by an observer-based fuzzy adaptive control algorithm as a whole rather than each individual pneumatic artificial muscle and parameters that are optimized by a neural network. Finally, experimental results are provided to confirm the effectiveness of the proposed method. We also document the role of muscle in trajectory tracking for the piriformis and musculi obturator internus in isobaric processes.

Extracting quantum dynamics from genetic learning algorithms through principal control analysis

International Nuclear Information System (INIS)

White, J L; Pearson, B J; Bucksbaum, P H

2004-01-01

Genetic learning algorithms are widely used to control ultrafast optical pulse shapes for photo-induced quantum control of atoms and molecules. An unresolved issue is how to use the solutions found by these algorithms to learn about the system's quantum dynamics. We propose a simple method based on covariance analysis of the control space, which can reveal the degrees of freedom in the effective control Hamiltonian. We have applied this technique to stimulated Raman scattering in liquid methanol. A simple model of two-mode stimulated Raman scattering is consistent with the results. (letter to the editor)

A HACCP-based approach to mastitis control in dairy herds. Part 1: Development.

Science.gov (United States)

Beekhuis-Gibbon, Lies; Whyte, Paul; O'Grady, Luke; More, Simon J; Doherty, Michael L

2011-03-31

Hazard Analysis and Critical Control Points (HACCP) systems are a risk based preventive approach developed to increase levels of food safety assurance. This is part 1 of a pilot study on the development, implementation and evaluation of a HACCP-based approach for the control of good udder health in dairy cows. The paper describes the use of a novel approach based on a deconstruction of the infectious process in mastitis to identify Critical Control Points (CCPs) and develop a HACCP-based system to prevent and control mastitis in dairy herds. The approach involved the creation of an Infectious Process Flow Diagram, which was then cross-referenced to two production process flow diagrams of the milking process and cow management cycle. The HACCP plan developed, may be suitable for customisation and implementation on dairy farms. This is a logical, systematic approach to the development of a mastitis control programme that could be used as a template for the development of control programmes for other infectious diseases in the dairy herd.

A HACCP-based approach to mastitis control in dairy herds. Part 1: Development

Directory of Open Access Journals (Sweden)

Beekhuis-Gibbon Lies

2011-03-01

Full Text Available Abstract Hazard Analysis and Critical Control Points (HACCP systems are a risk based preventive approach developed to increase levels of food safety assurance. This is part 1 of a pilot study on the development, implementation and evaluation of a HACCP-based approach for the control of good udder health in dairy cows. The paper describes the use of a novel approach based on a deconstruction of the infectious process in mastitis to identify Critical Control Points (CCPs and develop a HACCP-based system to prevent and control mastitis in dairy herds. The approach involved the creation of an Infectious Process Flow Diagram, which was then cross-referenced to two production process flow diagrams of the milking process and cow management cycle. The HACCP plan developed, may be suitable for customisation and implementation on dairy farms. This is a logical, systematic approach to the development of a mastitis control programme that could be used as a template for the development of control programmes for other infectious diseases in the dairy herd.

Crew Exploration Vehicle Launch Abort Controller Performance Analysis

Science.gov (United States)

Sparks, Dean W., Jr.; Raney, David L.

2007-01-01

This paper covers the simulation and evaluation of a controller design for the Crew Module (CM) Launch Abort System (LAS), to measure its ability to meet the abort performance requirements. The controller used in this study is a hybrid design, including features developed by the Government and the Contractor. Testing is done using two separate 6-degree-of-freedom (DOF) computer simulation implementations of the LAS/CM throughout the ascent trajectory: 1) executing a series of abort simulations along a nominal trajectory for the nominal LAS/CM system; and 2) using a series of Monte Carlo runs with perturbed initial flight conditions and perturbed system parameters. The performance of the controller is evaluated against a set of criteria, which is based upon the current functional requirements of the LAS. Preliminary analysis indicates that the performance of the present controller meets (with the exception of a few cases) the evaluation criteria mentioned above.

Xeroderma pigmentosum group D polymorphisms and esophageal cancer susceptibility: a meta-analysis based on case-control studies.

Science.gov (United States)

Yang, Rong; Zhang, Chong; Malik, Armah; Shen, Zhi-Da; Hu, Jian; Wu, Yi-He

2014-11-28

To clarify the effects of the xeroderma pigmentosum group D (XPD) Asp312Asn and Lys751Gln gene polymorphisms on the risk of esophageal cancer (EC). A computerised literature search was conducted to identify the relevant studies from the PUBMED and EMBASE databases, reviews, and reference lists of relevant articles. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the associations between the XPD Asp312Asn and/or Lys751Gln polymorphisms and EC susceptibility. Statistical analyses were performed using the software Stata 12.0. A fixed or random effects model was selected based on a heterogeneity test. Publication bias was estimated using funnel plots and Egger's linear regression method. Subgroup analyses were performed based on histological type and ethnicity. Thirteen case-control studies with a total of 10 comparisons for the Asp312Asn polymorphism, including 2373 cases and 3175 controls, and 15 comparisons for the Lys751Gln polymorphism, including 3226 cases and 5237 controls, were recruited for the meta-analysis. In terms of the XPD Asp312Asn polymorphism, significantly increased EC risks were identified in the Asp/Asn vs Asp/Asp comparison (OR = 1.17, 95%CI: 1.02-1.33, P = 0.03) and in the dominant-model comparison (Asn/Asn+Asp/Asn vs Asp/Asp: OR = 1.18, 95%CI: 1.04-1.34, P = 0.01). However, no significant associations were found in the Asn/Asn vs Asp/Asp comparison (OR = 1.30, 95%CI: 1.00-1.70, P = 0.05) or in the recessive-model comparison (Asn/Asn vs Asp/Asn + Asp/Asp: OR = 1.17, 95%CI: 0.91-1.50, P = 0.22). In terms of the XPD Lys751Gln polymorphism, a significant association with EC susceptibility was found under the recessive model (Gln/Gln vs Lys/Gln+Lys/Lys: OR = 1.21, 95%CI: 1.02-1.43, P = 0.03). However, no associations were identified in the other comparisons (co-dominant model: Lys/Gln vs Lys/Lys: OR = 1.11, 95%CI: 0.94-1.31, P = 0.20; Gln/Gln vs Lys/Lys: OR = 1.31, 95%CI: 0.98-1.75, P = 0.07; dominant model: OR = 1.14, 95%CI

An Analysis of the Control Hierarchy Modeling of the CMS Detector Control System

CERN Document Server

Ling Hwong, Yi

2010-01-01

The supervisory level of the Detector Control System (DCS) of the CMS experiment is implemented using Finite State Machines (FSM), which model the behaviors and control the operations of all the sub-detectors and support services. The FSM tree of the whole CMS experiment consists of more than 30.000 nodes. An analysis of a system of such size is a complex task but is a crucial step towards the improvement of the overall performance of the FSM system. This paper presents the analysis of the CMS FSM system using the micro Common Representation Language 2 (mcrl2) methodology. Individual mCRL2 models are obtained for the FSM systems of the CMS sub-detectors using the ASF+SDF automated translation tool. Different mCRL2 operations are applied to the mCRL2 models. A mCRL2 simulation tool is used to closer examine the system. Visualization of a system based on the exploration of its state space is enabled with a mCRL2 tool. Requirements such as command and state propagation are expressed using modal mu-calculus and c...

Simulation analysis of cascade controller for DC-DC bank converter

International Nuclear Information System (INIS)

Mahar, M.A.; Abro, M.R.; Larik, A.S.

2009-01-01

Power electronic converters are periodic variable structure systems due to their switched operation. During the last few decades several new dc-dc converter topologies have emerged. Buck converter being simple in topology, has recently drawn attraction of many researchers. Basically, a buck converter is highly underdamped system. In order to overcome the developed oscillations in output of this converter, various control techniques have been proposed. However, these techniques are fraught with many drawbacks. This paper focus on a cascade controller based buck topology. Steady state analysis is given in this paper which shows output voltage and inductor current in detail. Dynamic analysis for line and load variation is also presented. The buck topology is implemented and simulated in MATLAB/Simulink. The simulated results are presented. (author)

Gaze-Based Controlling a Vehicle

DEFF Research Database (Denmark)

Mardanbeigi, Diako; Witzner Hansen, Dan

) as an example of a complex gaze-based task in environment. This paper discusses the possibilities and limitations of how gaze interaction can be performed for controlling vehicles not only using a remote gaze tracker but also in general challenging situations where the user and robot are mobile...... modality if gaze trackers are embedded into the head- mounted devices. The domain of gaze-based interactive applications increases dramatically as interaction is no longer constrained to 2D displays. This paper proposes a general framework for gaze-based controlling a non- stationary robot (vehicle...... and the movements may be governed by several degrees of freedom (e.g. flying). A case study is also introduced where the mobile gaze tracker is used for controlling a Roomba vacuum cleaner....

Development of damage control training scenarios of naval ships based on simplified vulnerability analysis results

Directory of Open Access Journals (Sweden)

Dong-Ki Park

2016-07-01

Full Text Available Given the growing interest in damage control training for the naval ships and their organizations, expectations for a new concept of training program have also increased. The existing training programs and its concept focus on training crew to be more proficient and skilled so that they can respond better to damage situations, i.e., fires and flooding. This paper suggests a development procedure of damage control training scenarios using the survivability analysis results as a new concept of damage control training programs employing advanced systems such as damage control console, automation system, and kill cards. This approach could help the decision maker not only enhance his or her capability but also improve the reacting capability of crew members for complex situations induced by a weapon hit.

Internet and computer-based cognitive behavioral therapy for anxiety and depression in youth: a meta-analysis of randomized controlled outcome trials.

Directory of Open Access Journals (Sweden)

David Daniel Ebert

Full Text Available Anxiety and depression in children and adolescents are undertreated. Computer- and Internet-based cognitive behavioral treatments (cCBT may be an attractive treatment alternative to regular face-to-face treatment.This meta-analysis aims to evaluate whether cCBT is effective for treating symptoms of anxiety and depression in youth.We conducted systematic searches in bibliographical databases (Pubmed, Cochrane controlled trial register, PsychInfo up to December 4, 2013. Only randomized controlled trials in which a computer-, Internet- or mobile-based cognitive behavioral intervention targeting either depression, anxiety or both in children or adolescents up to the age of 25 were compared to a control condition were selected. We employed a random-effects pooling model in overall effect analyses and a mixed effect model for sub-group analyses. Searches resulted in identifying 13 randomized trials, including 796 children and adolescents that met inclusion criteria. Seven studies were directed at treating anxiety, four studies at depression, and two were of a transdiagnostic nature, targeting both anxiety and depression. The overall mean effect size (Hedges' g of cCBT on symptoms of anxiety or depression at post-test was g=0.72 (95% CI:0.55-0.90, numbers needed to be treated (NNT=2.56. Heterogeneity was low (I²=20.14%, 95% CI: 0-58%. The superiority of cCBT over controls was evident for interventions targeting anxiety (g=0.68; 95% CI: 0.45-0.92; p < .001; NNT=2.70 and for interventions targeting depression (g=0.76; 95% CI: 0.41-0.12; p < .001; NNT=2.44 as well as for transdiagnostic interventions (g=0.94; 95% CI: 0.23-2.66; p < .001; NNT=2.60.Results provide evidence for the efficacy of cCBT in the treatment of anxiety and depressive symptoms in youth. Hence, such interventions may be a promising treatment alternative when evidence based face-to-face treatment is not feasible. Future studies should examine long-term effects of treatments and should

Applications toolkit for accelerator control and analysis

International Nuclear Information System (INIS)

Borland, M.

1997-01-01

The Advanced Photon Source (APS) has taken a unique approach to creating high-level software applications for accelerator operation and analysis. The approach is based on self-describing data, modular program toolkits, and scripts. Self-describing data provide a communication standard that aids the creation of modular program toolkits by allowing compliant programs to be used in essentially arbitrary combinations. These modular programs can be used as part of an arbitrary number of high-level applications. At APS, a group of about 70 data analysis, manipulation, and display tools is used in concert with about 20 control-system-specific tools to implement applications for commissioning and operations. High-level applications are created using scripts, which are relatively simple interpreted programs. The Tcl/Tk script language is used, allowing creating of graphical user interfaces (GUIs) and a library of algorithms that are separate from the interface. This last factor allows greater automation of control by making it easy to take the human out of the loop. Applications of this methodology to operational tasks such as orbit correction, configuration management, and data review will be discussed

Noninteracting control of nonlinear systems based on relaxed control

NARCIS (Netherlands)

Jayawardhana, B.

2010-01-01

In this paper, we propose methodology to solve noninteracting control problem for general nonlinear systems based on the relaxed control technique proposed by Artstein. For a class of nonlinear systems which cannot be stabilized by smooth feedback, a state-feedback relaxed control can be designed to

Reliability analysis of digital based I and C system

Energy Technology Data Exchange (ETDEWEB)

Kang, I. S.; Cho, B. S.; Choi, M. J. [KOPEC, Yongin (Korea, Republic of)

1999-10-01

Rapidly, digital technology is being widely applied in replacing analog component installed in existing plant and designing new nuclear power plant for control and monitoring system in Korea as well as in foreign countries. Even though many merits of digital technology, it is being faced with a new problem of reliability assurance. The studies for solving this problem are being performed vigorously in foreign countries. The reliability of KNGR Engineered Safety Features Component Control System (ESF-CCS), digital based I and C system, was analyzed to verify fulfillment of the ALWR EPRI-URD requirement for reliability analysis and eliminate hazards in design applied new technology. The qualitative analysis using FMEA and quantitative analysis using reliability block diagram were performed. The results of analyses are shown in this paper.

Performance Comparison of Grid-Faulty Control Schemes for Inverter-Based Industrial Microgrids

Directory of Open Access Journals (Sweden)

Antonio Camacho

2017-12-01

Full Text Available Several control schemes specifically designed to operate inverter-based industrial microgrids during voltage sags have been recently proposed. This paper first classifies these control schemes in three categories and then performs a comparative analysis of them. Representative control schemes of each category are selected, described and used to identify the main features and performance of the considered category. The comparison is based on the evaluation of several indexes, which measure the power quality of the installation and utility grid during voltage sags, including voltage regulation, reactive current injection and transient response. The paper includes selected simulation results from a 500 kVA industrial microgrid to validate the expected features of the considered control schemes. Finally, in view of the obtained results, the paper proposes an alternative solution to cope with voltage sags, which includes the use of a static compensator in parallel with the microgrid. The novelty of this proposal is the suitable selection of the control schemes for both the microgrid and the static compensator. The superior performance of the proposal is confirmed by the analysis of the quality indexes. Its practical limitations are also revealed, showing that the topic studied in this paper is still open for further research.

The principles of analysis of competitiveness and control schemes in transport services

Directory of Open Access Journals (Sweden)

A. Žvirblis

2003-04-01

Full Text Available Under the conditions of constantly growing competition transportation companies are faced with theoretical and practical problems associated with the quality and stability of transport services, competitiveness on the market and marketing problems. Road transport services are considered in the terms of value analysis while the assessment of their competitiveness is based on the Pontriagin maximum principle. A model for transport risk analysis is constructed, taking into account the principles of correlation and co - variation of transport services. Formalized models of automated control of services in the system of marketing allowing the analysis of stability and other parameters to be made in the framework of automatic control theory are offered.

Adaptive control for solar energy based DC microgrid system development

Science.gov (United States)

Zhang, Qinhao

During the upgrading of current electric power grid, it is expected to develop smarter, more robust and more reliable power systems integrated with distributed generations. To realize these objectives, traditional control techniques are no longer effective in either stabilizing systems or delivering optimal and robust performances. Therefore, development of advanced control methods has received increasing attention in power engineering. This work addresses two specific problems in the control of solar panel based microgrid systems. First, a new control scheme is proposed for the microgrid systems to achieve optimal energy conversion ratio in the solar panels. The control system can optimize the efficiency of the maximum power point tracking (MPPT) algorithm by implementing two layers of adaptive control. Such a hierarchical control architecture has greatly improved the system performance, which is validated through both mathematical analysis and computer simulation. Second, in the development of the microgrid transmission system, the issues related to the tele-communication delay and constant power load (CPL)'s negative incremental impedance are investigated. A reference model based method is proposed for pole and zero placements that address the challenges of the time delay and CPL in closed-loop control. The effectiveness of the proposed modeling and control design methods are demonstrated in a simulation testbed. Practical aspects of the proposed methods for general microgrid systems are also discussed.

Dynamic Control Based Photovoltaic Illuminating System

Directory of Open Access Journals (Sweden)

Zhang Chengkai

2016-01-01

Full Text Available Smart LED illumination system can use the power from whether the photovoltaic cell or the power grid automatically based on the SOC (State Of Charge of the photovoltaic cell. This paper proposes a feedback control of the photovoltaic cells and a dynamic control strategy for the Energy system. The dynamic control strategy is used to determine the switching state of the photovoltaic cell based on the illumination load in the past one hour and the battery capacity. These controls are manifested by experimental prototype that the control scheme is correct and effective.

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. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Methodology for risk-based configuration control of nuclear power plant operation

International Nuclear Information System (INIS)

Valle, Antonio Torres; Oliva, Jose de Jesus Rivero

2012-01-01

The hazardous configurations control in Nuclear Power Plants is an application of a previous Probabilistic Safety Analysis (PSA). A more complete option would be the risk monitoring for the online detection of these configurations but expert personnel would be required to deal with the complexities of PSA and risk monitor. The paper presents a simpler but effective approach: a method of configuration control, based on dependencies matrixes. The algorithm is included in a computer code called SECURE A-Z. The configuration control is carried out in a qualitative way, without previous PSA results and not using a Risk Monitor. The simplicity of the method warrants its application to facilities where these tools have not been developed, allowing the detection of hazardous configurations during operation and increasing plant safety. This configuration control system was implemented in the Embalse Nuclear Power Plant in Argentina. The paper shows the application of the algorithm to the analysis of a simplified safety system. (author)

Disturbance observer based current controller for vector controlled IM drives

DEFF Research Database (Denmark)

Teodorescu, Remus; Dal, Mehmet

2008-01-01

induction motor (IM) drives. The control design, based on synchronously rotating d-q frame model of the machine, has a simple structure that combines the proportional portion of a conventional PI control and output of the observer. The observer is predicted to estimate the disturbances caused by parameters...... 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...

Finite element analysis-based design of a fluid-flow control nano-valve

International Nuclear Information System (INIS)

Grujicic, M.; Cao, G.; Pandurangan, B.; Roy, W.N.

2005-01-01

A finite element method-based procedure is developed for the design of molecularly functionalized nano-size devices. The procedure is aimed at the single-walled carbon nano-tubes (SWCNTs) used in the construction of such nano-devices and utilizes spatially varying nodal forces to represent electrostatic interactions between the charged groups of the functionalizing molecules. The procedure is next applied to the design of a fluid-flow control nano-valve. The results obtained suggest that the finite element-based procedure yields the results, which are very similar to their molecular modeling counterparts for small-size nano-valves, for which both types of analyses are feasible. The procedure is finally applied to optimize the design of a larger-size nano-valve, for which the molecular modeling approach is not practical

Robotic excavator trajectory control using an improved GA based PID controller

Science.gov (United States)

Feng, Hao; Yin, Chen-Bo; Weng, Wen-wen; Ma, Wei; Zhou, Jun-jing; Jia, Wen-hua; Zhang, Zi-li

2018-05-01

In order to achieve excellent trajectory tracking performances, an improved genetic algorithm (IGA) is presented to search for the optimal proportional-integral-derivative (PID) controller parameters for the robotic excavator. Firstly, the mathematical model of kinematic and electro-hydraulic proportional control system of the excavator are analyzed based on the mechanism modeling method. On this basis, the actual model of the electro-hydraulic proportional system are established by the identification experiment. Furthermore, the population, the fitness function, the crossover probability and mutation probability of the SGA are improved: the initial PID parameters are calculated by the Ziegler-Nichols (Z-N) tuning method and the initial population is generated near it; the fitness function is transformed to maintain the diversity of the population; the probability of crossover and mutation are adjusted automatically to avoid premature convergence. Moreover, a simulation study is carried out to evaluate the time response performance of the proposed controller, i.e., IGA based PID against the SGA and Z-N based PID controllers with a step signal. It was shown from the simulation study that the proposed controller provides the least rise time and settling time of 1.23 s and 1.81 s, respectively against the other tested controllers. Finally, two types of trajectories are designed to validate the performances of the control algorithms, and experiments are performed on the excavator trajectory control experimental platform. It was demonstrated from the experimental work that the proposed IGA based PID controller improves the trajectory accuracy of the horizontal line and slope line trajectories by 23.98% and 23.64%, respectively in comparison to the SGA tuned PID controller. The results further indicate that the proposed IGA tuning based PID controller is effective for improving the tracking accuracy, which may be employed in the trajectory control of an actual excavator.

User based preference indoor climate control

OpenAIRE

Zeiler, W.; Boxem, G.; Houten, van, M.A.; Wortel, W.; Velden, van der, J.A.J.; Kamphuis, I.G.; Hommelberg, M.P.F.; Tanabe, S.-I.; Kato, S.

2007-01-01

In comfort control strategy there is an exciting development based on inclusive design: the user’s preferences and their behaviour have become central in the building services control strategy. Synergy between end-user and building is the ultimate in the intelligent comfort control concept. This new comfort control technology is based on the use of the latest development in agent technology and can further reduce energy consumption of buildings while at the same time improve individual comfor...

Design and Analysis of Morpheus Lander Flight Control System

Science.gov (United States)

Jang, Jiann-Woei; Yang, Lee; Fritz, Mathew; Nguyen, Louis H.; Johnson, Wyatt R.; Hart, Jeremy J.

2014-01-01

The Morpheus Lander is a vertical takeoff and landing test bed vehicle developed to demonstrate the system performance of the Guidance, Navigation and Control (GN&C) system capability for the integrated autonomous landing and hazard avoidance system hardware and software. The Morpheus flight control system design must be robust to various mission profiles. This paper presents a design methodology for employing numerical optimization to develop the Morpheus flight control system. The design objectives include attitude tracking accuracy and robust stability with respect to rigid body dynamics and propellant slosh. Under the assumption that the Morpheus time-varying dynamics and control system can be frozen over a short period of time, the flight controllers are designed to stabilize all selected frozen-time control systems in the presence of parametric uncertainty. Both control gains in the inner attitude control loop and guidance gains in the outer position control loop are designed to maximize the vehicle performance while ensuring robustness. The flight control system designs provided herein have been demonstrated to provide stable control systems in both Draper Ares Stability Analysis Tool (ASAT) and the NASA/JSC Trick-based Morpheus time domain simulation.

State-Space Modeling and Performance Analysis of Variable-Speed Wind Turbine Based on a Model Predictive Control Approach

Directory of Open Access Journals (Sweden)

H. Bassi

2017-04-01

Full Text Available Advancements in wind energy technologies have led wind turbines from fixed speed to variable speed operation. This paper introduces an innovative version of a variable-speed wind turbine based on a model predictive control (MPC approach. The proposed approach provides maximum power point tracking (MPPT, whose main objective is to capture the maximum wind energy in spite of the variable nature of the wind’s speed. The proposed MPC approach also reduces the constraints of the two main functional parts of the wind turbine: the full load and partial load segments. The pitch angle for full load and the rotating force for the partial load have been fixed concurrently in order to balance power generation as well as to reduce the operations of the pitch angle. A mathematical analysis of the proposed system using state-space approach is introduced. The simulation results using MATLAB/SIMULINK show that the performance of the wind turbine with the MPC approach is improved compared to the traditional PID controller in both low and high wind speeds.

Research on Control Method Based on Real-Time Operational Reliability Evaluation for Space Manipulator

Directory of Open Access Journals (Sweden)

Yifan Wang

2014-05-01

Full Text Available A control method based on real-time operational reliability evaluation for space manipulator is presented for improving the success rate of a manipulator during the execution of a task. In this paper, a method for quantitative analysis of operational reliability is given when manipulator is executing a specified task; then a control model which could control the quantitative operational reliability is built. First, the control process is described by using a state space equation. Second, process parameters are estimated in real time using Bayesian method. Third, the expression of the system's real-time operational reliability is deduced based on the state space equation and process parameters which are estimated using Bayesian method. Finally, a control variable regulation strategy which considers the cost of control is given based on the Theory of Statistical Process Control. It is shown via simulations that this method effectively improves the operational reliability of space manipulator control system.

Milestones in screen-based process control

International Nuclear Information System (INIS)

Guesnier, G.P.

1995-01-01

The German approach is based on the utilisation of the conceptual elements of the PRISCA information system developed by Siemens and on operational experience with screen-based process control in a conventional power plant. In the French approach, the screen-based control room for the N4 plants, designed from scratch, has undergone extensive simulator tests for validation before going into realisation. It is now used in the commissioning phase of the first N4 plants. The design of the control room for the European Pressurized Water Reactor will be based on the common experience of Siemens and Electricite de France. Its main elements are several separate operator workstations, a safety control area used as a back-up for postulated failures of the workstations, and a commonly utilisable plant overview for the operators' coordination. (orig./HP) [de

Direct energy balance based active disturbance rejection control for coal-fired power plant.

Science.gov (United States)

Sun, Li; Hua, Qingsong; Li, Donghai; Pan, Lei; Xue, Yali; Lee, Kwang Y

2017-09-01

The conventional direct energy balance (DEB) based PI control can fulfill the fundamental tracking requirements of the coal-fired power plant. However, it is challenging to deal with the cases when the coal quality variation is present. To this end, this paper introduces the active disturbance rejection control (ADRC) to the DEB structure, where the coal quality variation is deemed as a kind of unknown disturbance that can be estimated and mitigated promptly. Firstly, the nonlinearity of a recent power plant model is analyzed based on the gap metric, which provides guidance on how to set the pressure set-point in line with the power demand. Secondly, the approximate decoupling effect of the DEB structure is analyzed based on the relative gain analysis in frequency domain. Finally, the synthesis of the DEB based ADRC control system is carried out based on multi-objective optimization. The optimized ADRC results show that the integrated absolute error (IAE) indices of the tracking performances in both loops can be simultaneously improved, in comparison with the DEB based PI control and H ∞ control system. The regulation performance in the presence of the coal quality variation is significantly improved under the ADRC control scheme. Moreover, the robustness of the proposed strategy is shown comparable with the H ∞ control. Copyright © 2017. Published by Elsevier Ltd.

Metabolic control analysis of biochemical pathways based on a thermokinetic description of reaction rates

DEFF Research Database (Denmark)

Nielsen, Jens Bredal

1997-01-01

Metabolic control analysis is a powerful technique for the evaluation of flux control within biochemical pathways. Its foundation is the elasticity coefficients and the flux control coefficients (FCCs). On the basis of a thermokinetic description of reaction rates it is here shown...... that the elasticity coefficients can be calculated directly from the pool levels of metabolites at steady state. The only requirement is that one thermodynamic parameter be known, namely the reaction affinity at the intercept of the tangent in the inflection point of the curve of reaction rate against reaction...... of the thermokinetic description of reaction rates to include the influence of effecters. Here the reaction rate is written as a linear function of the logarithm of the metabolite concentrations. With this type of rate function it is shown that the approach of Delgado and Liao [Biochem. J. (1992) 282, 919-927] can...

Switching and optimizing control for coal flotation process based on a hybrid model

Science.gov (United States)

Dong, Zhiyong; Wang, Ranfeng; Fan, Minqiang; Fu, Xiang

2017-01-01

Flotation is an important part of coal preparation, and the flotation column is widely applied as efficient flotation equipment. This process is complex and affected by many factors, with the froth depth and reagent dosage being two of the most important and frequently manipulated variables. This paper proposes a new method of switching and optimizing control for the coal flotation process. A hybrid model is built and evaluated using industrial data. First, wavelet analysis and principal component analysis (PCA) are applied for signal pre-processing. Second, a control model for optimizing the set point of the froth depth is constructed based on fuzzy control, and a control model is designed to optimize the reagent dosages based on expert system. Finally, the least squares-support vector machine (LS-SVM) is used to identify the operating conditions of the flotation process and to select one of the two models (froth depth or reagent dosage) for subsequent operation according to the condition parameters. The hybrid model is developed and evaluated on an industrial coal flotation column and exhibits satisfactory performance. PMID:29040305

PMU Measurement-Based Intelligent Strategy for Power System Controlled Islanding

Directory of Open Access Journals (Sweden)

Yi Tang

2018-01-01

Full Text Available Controlled islanding is an effective remedy to prevent large-area blackouts in a power system under a critically unstable condition. When and where to separate the power system are the essential issues facing controlled islanding. In this paper, both tasks are studied to ensure higher time efficiency and a better post-splitting restoration effect. A transient stability assessment model based on extreme learning machine (ELM and trajectory fitting (TF is constructed to determine the start-up criterion for controlled islanding. This model works through prompt stability status judgment with ELM and selective result amendment with TF to ensure that the assessment is both efficient and accurate. Moreover, a splitting surface searching algorithm, subject to minimal power disruption, is proposed for determination of the controlled islanding implementing locations. A highlight of this algorithm is a proposed modified electrical distance concept defined by active power magnitude and reactance on transmission lines that realize a computational burden reduction without feasible solution loss. Finally, the simulation results and comparison analysis based on the New England 39-bus test system validates the implementation effects of the proposed controlled islanding strategy.

Identification and control of chaos in nonlinear gear dynamic systems using Melnikov analysis

International Nuclear Information System (INIS)

Farshidianfar, A.; Saghafi, A.

2014-01-01

In this paper, the Melnikov analysis is extended to develop a practical model of gear system to control and eliminate the chaotic behavior. To this end, a nonlinear dynamic model of a spur gear pair with backlash, time-varying stiffness and static transmission error is established. Based on the Melnikov analysis the global homoclinic bifurcation and transition to chaos in this model are predicted. Then non-feedback control method is used to eliminate the chaos by applying an additional control excitation. The regions of the parameter space for the control excitation are obtained analytically. The accuracy of the theoretical predictions and also the performance of the proposed control system are verified by the comparison with the numerical simulations. The simulation results show effectiveness of the proposed control system and present some useful information to analyze and control the gear dynamical systems. - Highlights: • This study deals with the prediction and control of chaos in a nonlinear gear system. • Melnikov analysis is extended to present a practical gear system to control the chaos. • The proposed system is effective to eliminate the homoclinic bifurcation and chaos. • This controller is proposed as a way of implementing the chaos control in gear system

Composites Similarity Analysis Method Based on Knowledge Set in Composites Quality Control

OpenAIRE

Li Haifeng

2016-01-01

Composites similarity analysis is an important link of composites review, it can not only to declare composites review rechecking, still help composites applicants promptly have the research content relevant progress and avoid duplication. This paper mainly studies the composites similarity model in composites review. With the actual experience of composites management, based on the author’s knowledge set theory, paper analyzes deeply knowledge set representation of composites knowledge, impr...

Web-based control application using WebSocket

International Nuclear Information System (INIS)

Furukawa, Y.

2012-01-01

The WebSocket allows asynchronous full-duplex communication between a Web-based (i.e. Java Script-based) application and a Web-server. WebSocket started as a part of HTML5 standardization but has now been separated from HTML5 and has been developed independently. Using WebSocket, it becomes easy to develop platform independent presentation layer applications for accelerator and beamline control software. In addition, a Web browser is the only application program that needs to be installed on client computer. The WebSocket-based applications communicate with the WebSocket server using simple text-based messages, so WebSocket is applicable message-based control system like MADOCA, which was developed for the SPring-8 control system. A simple WebSocket server for the MADOCA control system and a simple motor control application were successfully made as a first trial of the WebSocket control application. Using Google-Chrome (version 13.0) on Debian/Linux and Windows 7, Opera (version 11.0) on Debian/Linux and Safari (version 5.0.3) on Mac OS X as clients, the motors can be controlled using a WebSocket-based Web-application. Diffractometer control application use in synchrotron radiation diffraction experiment was also developed. (author)

Association between Herpesviruses and Chronic Periodontitis: A Meta-Analysis Based on Case-Control Studies.

Science.gov (United States)

Zhu, Ce; Li, Fei; Wong, May Chun Mei; Feng, Xi-Ping; Lu, Hai-Xia; Xu, Wei

2015-01-01

Numerous studies have investigated the associations between herpesviruses and chronic periodontitis; however, the results remain controversial. To derive a more precise estimation, a meta-analysis on all available studies was performed to identify the association between herpesviruses and chronic periodontitis. A computerized literature search was conducted in December 2014 to identify eligible case-control studies from the PUBMED and EMBASE databases according to inclusion and exclusion criteria. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were used to assess the association between herpesviruses and risk of chronic periodontitis. A fixed or random effects model was determined based on a heterogeneity test. Sensitivity analysis was conducted to investigate stability and reliability. Publication bias was investigated using the Begg rank correlation test and Egger's funnel plot. Ten eligible studies were included to investigate the association between Epstein-Barr virus (EBV) and chronic periodontitis. The results showed that EBV has a significant association with chronic periodontitis compared with periodontally healthy group (OR = 5.74, 95% CI = 2.53-13.00, Pchronic periodontitis was analyzed in 10 studies. The pooled result showed that HCMV also has a significant association with chronic periodontitis (OR = 3.59, 95% CI = 1.41-9.16, P = 0.007). Similar results were found in the sensitivity analyses. No significant publication bias was observed. Two eligible studies were included to investigate the association between herpes simplex virus (HSV) and chronic periodontitis risk. The association between HSV and chronic periodontitis was inconclusive (OR = 2.81 95% CI = 0.95-8.27, P = 0.06). Only one included study investigated the association between human herpesvirus 7 (HHV-7) and chronic periodontitis risk (OR = 1.00, 95% CI = 0.21-4.86). The findings of this meta-analysis suggest that two members of the herpesvirus family, EBV

Novel neural networks-based fault tolerant control scheme with fault alarm.

Science.gov (United States)

Shen, Qikun; Jiang, Bin; Shi, Peng; Lim, Cheng-Chew

2014-11-01

In this paper, the problem of adaptive active fault-tolerant control for a class of nonlinear systems with unknown actuator fault is investigated. The actuator fault is assumed to have no traditional affine appearance of the system state variables and control input. The useful property of the basis function of the radial basis function neural network (NN), which will be used in the design of the fault tolerant controller, is explored. Based on the analysis of the design of normal and passive fault tolerant controllers, by using the implicit function theorem, a novel NN-based active fault-tolerant control scheme with fault alarm is proposed. Comparing with results in the literature, the fault-tolerant control scheme can minimize the time delay between fault occurrence and accommodation that is called the time delay due to fault diagnosis, and reduce the adverse effect on system performance. In addition, the FTC scheme has the advantages of a passive fault-tolerant control scheme as well as the traditional active fault-tolerant control scheme's properties. Furthermore, the fault-tolerant control scheme requires no additional fault detection and isolation model which is necessary in the traditional active fault-tolerant control scheme. Finally, simulation results are presented to demonstrate the efficiency of the developed techniques.

Nonlinear control strategy based on using a shape-tunable neural controller

Energy Technology Data Exchange (ETDEWEB)

Chen, C.; Peng, S. [Feng Chia Univ, Taichung (Taiwan, Province of China). Department of chemical Engineering; Chang, W. [Feng Chia Univ, Taichung (Taiwan, Province of China). Department of Automatic Control

1997-08-01

In this paper, a nonlinear control strategy based on using a shape-tunable neural network is developed for adaptive control of nonlinear processes. Based on the steepest descent method, a learning algorithm that enables the neural controller to possess the ability of automatic controller output range adjustment is derived. The novel feature of automatic output range adjustment provides the neural controller more flexibility and capability, and therefore the scaling procedure, which is usually unavoidable for the conventional fixed-shape neural controllers, becomes unnecessary. The advantages and effectiveness of the proposed nonlinear control strategy are demonstrated through the challenge problem of controlling an open-loop unstable nonlinear continuous stirred tank reactor (CSTR). 14 refs., 11 figs.

Model-based nonlinear control of hydraulic servo systems: Challenges, developments and perspectives

Science.gov (United States)

Yao, Jianyong

2018-06-01

Hydraulic servo system plays a significant role in industries, and usually acts as a core point in control and power transmission. Although linear theory-based control methods have been well established, advanced controller design methods for hydraulic servo system to achieve high performance is still an unending pursuit along with the development of modern industry. Essential nonlinearity is a unique feature and makes model-based nonlinear control more attractive, due to benefit from prior knowledge of the servo valve controlled hydraulic system. In this paper, a discussion for challenges in model-based nonlinear control, latest developments and brief perspectives of hydraulic servo systems are presented: Modelling uncertainty in hydraulic system is a major challenge, which includes parametric uncertainty and time-varying disturbance; some specific requirements also arise ad hoc difficulties such as nonlinear friction during low velocity tracking, severe disturbance, periodic disturbance, etc.; to handle various challenges, nonlinear solutions including parameter adaptation, nonlinear robust control, state and disturbance observation, backstepping design and so on, are proposed and integrated, theoretical analysis and lots of applications reveal their powerful capability to solve pertinent problems; and at the end, some perspectives and associated research topics (measurement noise, constraints, inner valve dynamics, input nonlinearity, etc.) in nonlinear hydraulic servo control are briefly explored and discussed.

Enhanced robust fractional order proportional-plus-integral controller based on neural network for velocity control of permanent magnet synchronous motor.

Science.gov (United States)

Zhang, Bitao; Pi, YouGuo

2013-07-01

The traditional integer order proportional-integral-differential (IO-PID) controller is sensitive to the parameter variation or/and external load disturbance of permanent magnet synchronous motor (PMSM). And the fractional order proportional-integral-differential (FO-PID) control scheme based on robustness tuning method is proposed to enhance the robustness. But the robustness focuses on the open-loop gain variation of controlled plant. In this paper, an enhanced robust fractional order proportional-plus-integral (ERFOPI) controller based on neural network is proposed. The control law of the ERFOPI controller is acted on a fractional order implement function (FOIF) of tracking error but not tracking error directly, which, according to theory analysis, can enhance the robust performance of system. Tuning rules and approaches, based on phase margin, crossover frequency specification and robustness rejecting gain variation, are introduced to obtain the parameters of ERFOPI controller. And the neural network algorithm is used to adjust the parameter of FOIF. Simulation and experimental results show that the method proposed in this paper not only achieve favorable tracking performance, but also is robust with regard to external load disturbance and parameter variation. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Analysis and control of high power synchronous rectifier

Energy Technology Data Exchange (ETDEWEB)

Singh Tejinder.

1993-01-01

The description, steady state/dynamic analysis and control design of a high power synchronous rectifier is presented. The proposed rectifier system exploits selective harmonic elimination modulation techniques to minimize filtering requirements, and overcomes the dc voltage limitations of prior art equipment. A detailed derivation of the optimum pulse width modulation switching patterns, in the low frequency range for high power applications is presented. A general mathematical model of the rectifier is established which is non-linear and time-invariant. The transformation of reference frame and small signal linearization techniques are used to obtain closed form solutions from the mathematical model. The modelling procedure is verified by computer simulation. The closed loop design of the synchronous rectifier based on a phase and amplitude control strategy is investigated. The transfer functions derived from this analysis are used for the design of the regulators. The steady-state and dynamic results predicted by computer simulation are verified by PECAN. A systematic design procedure is developed and a detailed design example of a 1 MV-amp rectifer system is presented. 23 refs., 33 figs.

CONCEPT ANALYSIS OF PERCEIVED CONTROL

Directory of Open Access Journals (Sweden)

Mardiyono Mardiyono

2011-07-01

Full Text Available Background. Perceived control is a personality characteristic that contributes psychological adjustment. It was derived from various theories, so that definitions of perceived control were ambiguous meaning. Disclosing concept of perceived control is required.Objective. The analysis aims to identify definition and use of perceived control, examine the basic attributes of perceived control, and the measurements of perceived control.Method. Databases searched for electronic journals and books that were published from 1994 to 2010 were analyzed.Result. Perceived control is personal belief that refers to controllability on behalf of one’s self and ability to control threats or events. The use of perceived control includes maternal, pediatric, medical, surgical, psychiatric, community nursing, and pain management. Perceived control was composed of two dimensions: belief about controllability and belief about ability to control to threats.Conclusion. Instrument of Anxiety Control Questionnaire most closely corresponds to two dimensions: belief about controllability and ability to control. Defining attributes and dimensions of perceived control are useful for developing tool.Keywords: perceived control, controllability, ability to control, and agency

Analysis and Implementation of an Open Programmable Router Based on Forwarding and Control Element Separation

Institute of Scientific and Technical Information of China (English)

Wei-Ming Wang; Li-Gang Dong; Bin Zhuge

2008-01-01

A router architecture based upon ForCES (Forwarding and Control Element Separation), which is being standardized by IETF ForCES working group, gains its competitive advantage over traditional router architectures in flexibility, programmability, and cost-effectiveness. In this paper, design and implementation of a ForCES-based router (ForTER) is illustrated. Firstly, the implementation architecture of ForTER is discussed. Then, a layered software model,which well illustrates ForCES features, is proposed. Based on the model, design and implementation of Control Element (CE) and Forwarding Element (FE) in ForTER are introduced in detail. Moreover, security for ForTER is considered and an algorithm to prevent DoS attacks is presented. Lastly, experiments of ForTER are illustrated for routing and running routing protocols, network management, DoS attack prevention, etc. The experimental results show the feasibility of the ForTER design. Consequently, the ForTER implementation basically testifies the feasibility of ForCES architecture and some IETF ForCES specifications.

Incorporating Traffic Control and Safety Hardware Performance Functions into Risk-based Highway Safety Analysis

Directory of Open Access Journals (Sweden)

Zongzhi Li

2017-04-01

Full Text Available Traffic control and safety hardware such as traffic signs, lighting, signals, pavement markings, guardrails, barriers, and crash cushions form an important and inseparable part of highway infrastructure affecting safety performance. Significant progress has been made in recent decades to develop safety performance functions and crash modification factors for site-specific crash predictions. However, the existing models and methods lack rigorous treatments of safety impacts of time-deteriorating conditions of traffic control and safety hardware. This study introduces a refined method for computing the Safety Index (SI as a means of crash predictions for a highway segment that incorporates traffic control and safety hardware performance functions into the analysis. The proposed method is applied in a computation experiment using five-year data on nearly two hundred rural and urban highway segments. The root-mean square error (RMSE, Chi-square, Spearman’s rank correlation, and Mann-Whitney U tests are employed for validation.

Analysis And Control System For Automated Welding

Science.gov (United States)

Powell, Bradley W.; Burroughs, Ivan A.; Kennedy, Larry Z.; Rodgers, Michael H.; Goode, K. Wayne

1994-01-01

Automated variable-polarity plasma arc (VPPA) welding apparatus operates under electronic supervision by welding analysis and control system. System performs all major monitoring and controlling functions. It acquires, analyzes, and displays weld-quality data in real time and adjusts process parameters accordingly. Also records pertinent data for use in post-weld analysis and documentation of quality. System includes optoelectronic sensors and data processors that provide feedback control of welding process.

A model-based control system concept

International Nuclear Information System (INIS)

Aarzen, K.E.

1992-12-01

This paper presents an overview of a new concept for DCSs developed within the KBRTCS (Knowledge-Based Real-Time Control Systems) project performed between 1988 and 1991 as a part of the Swedish IT4 programme. The partners of the project have been the Department of Automatic Control at Lund University, Asea Brown Boveri, and during parts of the project, SattControl, and TeleLogic. The aim of the project has been to develop a concept for future generations of DCSs based on a plant database containing a description of the plant together with the control system. The database is object-based and supports multiple views of an objects. A demonstrator is presented where a DCS system of this type is emulated. The demonstrator contains a number of control, monitoring, and diagnosis applications that execute in real time against a simulations of Steritherm sterilization process. (25 refs.)

Sensorless Control Technology for PMSG base on the Dead-time Compensation voltage

Directory of Open Access Journals (Sweden)

Yang Li-yong

2015-01-01

Full Text Available In order to improve the speed sensorless-control system of PMSG in low speed performance, this paper introduces a novel Dead-time compensation control method .Mathematical model is established according to the Dead-zone of the influence of the voltage source type inverter output voltage. At the same time, the given value of current regulator output voltage has been fixed based on the established model. Then the stator voltage after compensationed is applied to the flux estimation, which improves the performance of flux estimation. Finally, the position and speed of the rotor is estimated based on Back-Electromotive Force, which has Simple algorithm and good robustness. In order to verify the correctness of theoretical analysis, the experiment was done according to the new control method. The results proved the correctness and feasibility of this control method.

Modeling and Sensitivity Study of Consensus Algorithm-Based Distributed Hierarchical Control for DC Microgrids

DEFF Research Database (Denmark)

Meng, Lexuan; Dragicevic, Tomislav; Roldan Perez, Javier

2016-01-01

Distributed control methods based on consensus algorithms have become popular in recent years for microgrid (MG) systems. These kinds of algorithms can be applied to share information in order to coordinate multiple distributed generators within a MG. However, stability analysis becomes a challen......Distributed control methods based on consensus algorithms have become popular in recent years for microgrid (MG) systems. These kinds of algorithms can be applied to share information in order to coordinate multiple distributed generators within a MG. However, stability analysis becomes...... in the communication network, continuous-time methods can be inaccurate for this kind of dynamic study. Therefore, this paper aims at modeling a complete DC MG using a discrete-time approach in order to perform a sensitivity analysis taking into account the effects of the consensus algorithm. To this end......, a generalized modeling method is proposed and the influence of key control parameters, the communication topology and the communication speed are studied in detail. The theoretical results obtained with the proposed model are verified by comparing them with the results obtained with a detailed switching...

An analysis of the control hierarchy modelling of the CMS detector control system

Energy Technology Data Exchange (ETDEWEB)

Hwong, Yi-Ling; et al.

2011-01-01

The supervisory level of the Detector Control System (DCS) of the CMS experiment is implemented using Finite State Machines (FSM), which model the behaviours and control the operations of all the sub-detectors and support services. The FSM tree of the whole CMS experiment consists of more than 30.000 nodes. An analysis of a system of such size is a complex task but is a crucial step towards the improvement of the overall performance of the FSM system. This paper presents the analysis of the CMS FSM system using the micro Common Representation Language 2 (mcrl2) methodology. Individual mCRL2 models are obtained for the FSM systems of the CMS sub-detectors using the ASF+SDF automated translation tool. Different mCRL2 operations are applied to the mCRL2 models. A mCRL2 simulation tool is used to closer examine the system. Visualization of a system based on the exploration of its state space is enabled with a mCRL2 tool. Requirements such as command and state propagation are expressed using modal mu-calculus and checked using a model checking algorithm. For checking local requirements such as endless loop freedom, the Bounded Model Checking technique is applied. This paper discusses these analysis techniques and presents the results of their application on the CMS FSM system.

Cost--effectiveness analysis of salpingectomy prior to IVF, based on a randomized controlled trial.

Science.gov (United States)

Strandell, Annika; Lindhard, Anette; Eckerlund, Ingemar

2005-12-01

In patients with ultrasound-visible hydrosalpinges, salpingectomy prior to IVF increases the chance of a live birth. This study compared the cost-effectiveness of this strategy (intervention) with that of optional salpingectomy after a failed cycle (control). Data from a Scandinavian randomized controlled trial were used to calculate the individual number of treatments and their outcomes. Only patients with ultrasound-visible hydrosalpinges were considered in the main analysis, and a maximum of three fresh cycles were included. The costs for surgical procedures, IVF treatment, medication, complications, management of pregnancy and delivery as well as of early pregnancy losses were calculated from standardized hospital charges. Among the 51 patients in the intervention group, the live birth rate was 60.8% compared with 40.9% in 44 controls. The average cost per patient was 13,943 euro and 12,091 euro, respectively. Thus, the average cost per live birth was 22,823 euro in the intervention group and 29,517 euro in the control group. The incremental cost-effectiveness ratio for adopting the intervention strategy was estimated at 9306 euro. The incremental cost to achieve the higher birth rate of the intervention strategy seems reasonable.

The Absolute Stability Analysis in Fuzzy Control Systems with Parametric Uncertainties and Reference Inputs

Science.gov (United States)

Wu, Bing-Fei; Ma, Li-Shan; Perng, Jau-Woei

This study analyzes the absolute stability in P and PD type fuzzy logic control systems with both certain and uncertain linear plants. Stability analysis includes the reference input, actuator gain and interval plant parameters. For certain linear plants, the stability (i.e. the stable equilibriums of error) in P and PD types is analyzed with the Popov or linearization methods under various reference inputs and actuator gains. The steady state errors of fuzzy control systems are also addressed in the parameter plane. The parametric robust Popov criterion for parametric absolute stability based on Lur'e systems is also applied to the stability analysis of P type fuzzy control systems with uncertain plants. The PD type fuzzy logic controller in our approach is a single-input fuzzy logic controller and is transformed into the P type for analysis. In our work, the absolute stability analysis of fuzzy control systems is given with respect to a non-zero reference input and an uncertain linear plant with the parametric robust Popov criterion unlike previous works. Moreover, a fuzzy current controlled RC circuit is designed with PSPICE models. Both numerical and PSPICE simulations are provided to verify the analytical results. Furthermore, the oscillation mechanism in fuzzy control systems is specified with various equilibrium points of view in the simulation example. Finally, the comparisons are also given to show the effectiveness of the analysis method.

Human reliability analysis for advanced control room of KNGR

International Nuclear Information System (INIS)

Kim, Myung-Ro; Park, Seong-Kyu

2000-01-01

There are two purposes in Human Reliability Analysis (HRA) which was performed during Korean Next Generation Reactor (KNGR) Phase 2 research project. One is to present the human error probability quantification results for Probabilistic Safety Assessment (PSA) and the other is to provide a list of the critical operator actions for Human Factor Engineering (HFE). Critical operator actions were identified from the KNGR HRA/RSA based on selection criteria and incorporated in the MMI Task Analysis, where they receive additional treatment. The use of HRA/PSA results in design, procedure development, and training was ensured by their incorporation in the MMI task analysis and MCR design such as fixed position alarms, displays and controls. Any dominant PSA sequence that takes credit for human performance to achieve acceptable results was incorporated in MMIS validation activities through the PSA-based critical operator actions. The integration of KNGR HRA into MMI design was sufficiently addressed all applicable review criteria of NUREG-0800, Chapter 18, Section 2 F and NUREG-0711. (S.Y.)

Prison tobacco control policies and deaths from smoking in United States prisons: population based retrospective analysis.

Science.gov (United States)

Binswanger, Ingrid A; Carson, E Ann; Krueger, Patrick M; Mueller, Shane R; Steiner, John F; Sabol, William J

2014-08-05

To determine the mortality attributable to smoking and years of potential life lost from smoking among people in prison and whether bans on smoking in prison are associated with reductions in smoking related deaths. Analysis of cross sectional survey data with the smoking attributable mortality, morbidity, and economic costs system; population based time series analysis. All state prisons in the United States. Prevalence of smoking from cross sectional survey of inmates in state correctional facilities. Data on state prison tobacco policies from web based searches of state policies and legislation. Deaths and causes of death in US state prisons from the deaths in custody reporting program of the Bureau of Justice Statistics for 2001-11. Smoking attributable mortality and years of potential life lost was assessed from the smoking attributable mortality, morbidity, and economic costs system of the Centers for Disease Control and Prevention. Multivariate Poisson models quantified the association between bans and smoking related cancer, cardiovascular and pulmonary deaths. The most common causes of deaths related to smoking among people in prison were lung cancer, ischemic heart disease, other heart disease, cerebrovascular disease, and chronic airways obstruction. The age adjusted smoking attributable mortality and years of potential life lost rates were 360 and 5149 per 100,000, respectively; these figures are higher than rates in the general US population (248 and 3501, respectively). The number of states with any smoking ban increased from 25 in 2001 to 48 by 2011. In prisons the mortality rate from smoking related causes was lower during years with a ban than during years without a ban (110.4/100,000 v 128.9/100,000). Prisons that implemented smoking bans had a 9% reduction (adjusted incidence rate ratio 0.91, 95% confidence interval 0.88 to 0.95) in smoking related deaths. Bans in place for longer than nine years were associated with reductions in cancer

Passivity-based model predictive control for mobile vehicle motion planning

CERN Document Server

Tahirovic, Adnan

2013-01-01

Passivity-based Model Predictive Control for Mobile Vehicle Navigation represents a complete theoretical approach to the adoption of passivity-based model predictive control (MPC) for autonomous vehicle navigation in both indoor and outdoor environments. The brief also introduces analysis of the worst-case scenario that might occur during the task execution. Some of the questions answered in the text include: • how to use an MPC optimization framework for the mobile vehicle navigation approach; • how to guarantee safe task completion even in complex environments including obstacle avoidance and sideslip and rollover avoidance; and  • what to expect in the worst-case scenario in which the roughness of the terrain leads the algorithm to generate the longest possible path to the goal. The passivity-based MPC approach provides a framework in which a wide range of complex vehicles can be accommodated to obtain a safer and more realizable tool during the path-planning stage. During task execution, the optimi...

Intelligent control of HVAC systems. Part II: perceptron performance analysis

Directory of Open Access Journals (Sweden)

Ioan URSU

2013-09-01

Full Text Available This is the second part of a paper on intelligent type control of Heating, Ventilating, and Air-Conditioning (HVAC systems. The whole study proposes a unified approach in the design of intelligent control for such systems, to ensure high energy efficiency and air quality improving. In the first part of the study it is considered as benchmark system a single thermal space HVAC system, for which it is assigned a mathematical model of the controlled system and a mathematical model(algorithm of intelligent control synthesis. The conception of the intelligent control is of switching type, between a simple neural network, a perceptron, which aims to decrease (optimize a cost index,and a fuzzy logic component, having supervisory antisaturating role for neuro-control. Based on numerical simulations, this Part II focuses on the analysis of system operation in the presence only ofthe neural control component. Working of the entire neuro-fuzzy system will be reported in a third part of the study.

Zero-dimensional analysis of burn control with compression-decompression

International Nuclear Information System (INIS)

Okamoto, Masao; Ohnishi, Masami

1983-01-01

A simple but realistic method of active feedback control of a self-ignited tokamak reactor by major radius compression-decompression is presented, in which the thermal fusion output power and the ion temperature are envisaged as the variables that could be adopted as object of control. Error inherent in the measuring system for the controlled variable is taken into account in the analysis. Numerical calculations based on a point reactor model are performed, which indicate that the proposed method of control is capable of completely suppressing thermal runaway without involving any significant change in the major radius or in the fusion output power. Matching the reactor output to changes in load is shown also to be possible from a numerical example. The thermal stability of an igniting plasma governed by this feedback control is analyzed without prescribing any particular transport scaling. It is revealed that the control is achievable for a suitably chosen gain even with a response time lag longer than the thermal runaway time. Strong dependence of the stability on the scaling law is indicated. (author)

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

Design, analysis and control of large transports so that control of engine thrust can be used as a back-up of the primary flight controls. Ph.D. Thesis

Science.gov (United States)

Roskam, Jan; Ackers, Deane E.; Gerren, Donna S.

1995-01-01

A propulsion controlled aircraft (PCA) system has been developed at NASA Dryden Flight Research Center at Edwards Air Force Base, California, to provide safe, emergency landing capability should the primary flight control system of the aircraft fail. As a result of the successful PCA work being done at NASA Dryden, this project investigated the possibility of incorporating the PCA system as a backup flight control system in the design of a large, ultra-high capacity megatransport in such a way that flight path control using only the engines is not only possible, but meets MIL-Spec Level 1 or Level 2 handling quality requirements. An 800 passenger megatransport aircraft was designed and programmed into the NASA Dryden simulator. Many different analysis methods were used to evaluate the flying qualities of the megatransport while using engine thrust for flight path control, including: (1) Bode and root locus plot analysis to evaluate the frequency and damping ratio response of the megatransport; (2) analysis of actual simulator strip chart recordings to evaluate the time history response of the megatransport; and (3) analysis of Cooper-Harper pilot ratings by two NaSA test pilots.

Data acquisition, control, and analysis for the Argonne Advanced Accelerator Test Facility (AATF)

International Nuclear Information System (INIS)

Schoessow, P.

1989-01-01

The AATF has been used to study wakefield acceleration and focusing in plasmas and rf structures. A PC-based system is described which incorporates the functions of beamline control and acquisition, storage, and preliminary analysis of video images from luminescent screen beam diagnostics. General features of the offline analysis of wakefield data are also discussed. 4 refs., 3 figs

Virtual velocity loop based on MEMS accelerometers for optical stabilization control system

Science.gov (United States)

Ren, Wei; Deng, Chao; Mao, Yao; Ren, Ge

2017-08-01

In the optical stabilization control system (OSCS) control system based on a charge-coupled device (CCD), stabilization performance of the line-of-sight is severely limited by the mechanical resonance and the low sampling rate of the CCD. An approach to improve the stabilization performance of the OSCS control system with load restriction based on three loops, including an acceleration loop, a virtual velocity loop, and a position loop, by using MEMS accelerometers and a CCD is proposed. The velocity signal is obtained by accelerators instead of gyro sensors. Its advantages are low power, low cost, small size, and wide measuring range. A detailed analysis is provided to show how to design the virtual velocity loop and correct virtual velocity loop drift. Experimental results show that the proposed multiloop feedback control method with virtual velocity loop in which the disturbance suppression performance is better than that of the dual loop control with only an acceleration loop and a position loop at low frequency.

Analysis on nuclear power plant control room system design and improvement based on human factor engineering

International Nuclear Information System (INIS)

Gao Feng; Liu Yanzi; Sun Yongbin

2014-01-01

The design of nuclear power plant control room system is a process of improvement with the implementation of human factor engineering theory and guidance. The method of implementation human factor engineering principles into the nuclear power plant control room system design and improvement was discussed in this paper. It is recommended that comprehensive address should be done from control room system function, human machine interface, digital procedure, control room layout and environment design based on the human factor engineering theory and experience. The main issues which should be paid more attention during the control room system design and improvement also were addressed in this paper, and then advices and notices for the design and improvement of the nuclear power plant control room system were afforded. (authors)

Experimental analysis of fuzzy controlled energy efficient demand controlled ventilation economizer cycle variable air volume air conditioning system

Directory of Open Access Journals (Sweden)

Rajagopalan Parameshwaran

2008-01-01

Full Text Available In the quest for energy conservative building design, there is now a great opportunity for a flexible and sophisticated air conditioning system capable of addressing better thermal comfort, indoor air quality, and energy efficiency, that are strongly desired. The variable refrigerant volume air conditioning system provides considerable energy savings, cost effectiveness and reduced space requirements. Applications of intelligent control like fuzzy logic controller, especially adapted to variable air volume air conditioning systems, have drawn more interest in recent years than classical control systems. An experimental analysis was performed to investigate the inherent operational characteristics of the combined variable refrigerant volume and variable air volume air conditioning systems under fixed ventilation, demand controlled ventilation, and combined demand controlled ventilation and economizer cycle techniques for two seasonal conditions. The test results of the variable refrigerant volume and variable air volume air conditioning system for each techniques are presented. The test results infer that the system controlled by fuzzy logic methodology and operated under the CO2 based mechanical ventilation scheme, effectively yields 37% and 56% per day of average energy-saving in summer and winter conditions, respectively. Based on the experimental results, the fuzzy based combined system can be considered to be an alternative energy efficient air conditioning scheme, having significant energy-saving potential compared to the conventional constant air volume air conditioning system.

Development of tools for safety analysis of control software in advanced reactors

International Nuclear Information System (INIS)

Guarro, S.; Yau, M.; Motamed, M.

1996-04-01

Software based control systems have gained a pervasive presence in a wide variety of applications, including nuclear power plant control and protection systems which are within the oversight and licensing responsibility of the US Nuclear Regulatory Commission. While the cost effectiveness and flexibility of software based plant process control is widely recognized, it is very difficult to achieve and prove high levels of demonstrated dependability and safety assurance for the functions performed by process control software, due to the very flexibility and potential complexity of the software itself. The development of tools to model, analyze and test software design and implementations in the context of the system that the software is designed to control can greatly assist the task of providing higher levels of assurance than those obtainable by software testing alone. This report presents and discusses the development of the Dynamic Flowgraph Methodology (DFM) and its application in the dependability and assurance analysis of software-based control systems. The features of the methodology and full-scale examples of application to both generic process and nuclear power plant control systems are presented and discussed in detail. The features of a workstation software tool developed to assist users in the application of DFM are also described

Development of tools for safety analysis of control software in advanced reactors

Energy Technology Data Exchange (ETDEWEB)

Guarro, S.; Yau, M.; Motamed, M. [Advanced Systems Concepts Associates, El Segundo, CA (United States)

1996-04-01

Software based control systems have gained a pervasive presence in a wide variety of applications, including nuclear power plant control and protection systems which are within the oversight and licensing responsibility of the US Nuclear Regulatory Commission. While the cost effectiveness and flexibility of software based plant process control is widely recognized, it is very difficult to achieve and prove high levels of demonstrated dependability and safety assurance for the functions performed by process control software, due to the very flexibility and potential complexity of the software itself. The development of tools to model, analyze and test software design and implementations in the context of the system that the software is designed to control can greatly assist the task of providing higher levels of assurance than those obtainable by software testing alone. This report presents and discusses the development of the Dynamic Flowgraph Methodology (DFM) and its application in the dependability and assurance analysis of software-based control systems. The features of the methodology and full-scale examples of application to both generic process and nuclear power plant control systems are presented and discussed in detail. The features of a workstation software tool developed to assist users in the application of DFM are also described.

Perturbation analysis of linear control problems

International Nuclear Information System (INIS)

Petkov, Petko; Konstantinov, Mihail

2017-01-01

The paper presents a brief overview of the technique of splitting operators, proposed by the authors and intended for perturbation analysis of control problems involving unitary and orthogonal matrices. Combined with the technique of Lyapunov majorants and the implementation of the Banach and Schauder fixed point principles, it allows to obtain rigorous non-local perturbation bounds for a set of sensitivity analysis problems. Among them are the reduction of linear systems into orthogonal canonical forms, the feedback synthesis problem and pole assignment problem in particular, as well as other important problems in control theory and linear algebra. Key words: perturbation analysis, canonical forms, feedback synthesis

Cloud-based Networked Visual Servo Control

OpenAIRE

Wu, Haiyan; Lu, Lei; Chen, Chih-Chung; Hirche, Sandra; Kühnlenz, Kolja

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 transmitti...

An oven control system based on MCU MSP430F149

International Nuclear Information System (INIS)

Jing Lan; Zhu Haijun; Liu Caihong; Liu Yali; Gao Shiwei; Chinese Academia of Sciences, Beijing

2004-01-01

This paper introduces the structure, principle and feature of new generation of 16 bit and Flash-type microcontroller which belongs to the Texas Instruments MSP430F149 series with low power consumption and high performance. Details of the hardware structure and analysis software of the oven control system based on the microcontroller are expatiated. this systerm has the characteristics of strong function, simple struction, high reliability, strong noise resistances, no peripheral chip etc. The requirements of the temperature measurement and control system are fulfilled. (authors)

Proportional derivative based stabilizing control of paralleled grid converters with cables in renewable power plants

DEFF Research Database (Denmark)

Wang, Xiongfei; Blaabjerg, Frede; Loh, Poh Chiang

2014-01-01

consisting in LCL filters and cables. Both grid and converter current controls are analyzed. The frequency region, within which the system may be destabilized, is identified by means of the impedance-based stability analysis and frequency-domain passivity theory. A proportional derivative control strategy...

Inventory Control System for a Healthcare Apparel Service Centre with Stockout Risk: A Case Analysis.

Science.gov (United States)

Pan, An; Hui, Chi-Leung

2017-01-01

Based on the real-world inventory control problem of a capacitated healthcare apparel service centre in Hong Kong which provides tailor-made apparel-making services for the elderly and disabled people, this paper studies a partial backordered continuous review inventory control problem in which the product demand follows a Poisson process with a constant lead time. The system is controlled by an ( Q , r ) inventory policy which incorporate the stockout risk, storage capacity, and partial backlog. The healthcare apparel service centre, under the capacity constraint, aims to minimize the inventory cost and achieving a low stockout risk. To address this challenge, an optimization problem is constructed. A real case-based data analysis is conducted, and the result shows that the expected total cost on an order cycle is reduced substantially at around 20% with our proposed optimal inventory control policy. An extensive sensitivity analysis is conducted to generate additional insights.

State-space-based harmonic stability analysis for paralleled grid-connected inverters

DEFF Research Database (Denmark)

Wang, Yanbo; Wang, Xiongfei; Chen, Zhe

2016-01-01

This paper addresses a state-space-based harmonic stability analysis of paralleled grid-connected inverters system. A small signal model of individual inverter is developed, where LCL filter, the equivalent delay of control system, and current controller are modeled. Then, the overall small signal...... model of paralleled grid-connected inverters is built. Finally, the state space-based stability analysis approach is developed to explain the harmonic resonance phenomenon. The eigenvalue traces associated with time delay and coupled grid impedance are obtained, which accounts for how the unstable...... inverter produces the harmonic resonance and leads to the instability of whole paralleled system. The proposed approach reveals the contributions of the grid impedance as well as the coupled effect on other grid-connected inverters under different grid conditions. Simulation and experimental results...

Analysis of Human Error Types and Performance Shaping Factors in the Next Generation Main Control Room

International Nuclear Information System (INIS)

Sin, Y. C.; Jung, Y. S.; Kim, K. H.; Kim, J. H.

2008-04-01

Main control room of nuclear power plants has been computerized and digitalized in new and modernized plants, as information and digital technologies make great progresses and become mature. Survey on human factors engineering issues in advanced MCRs: Model-based approach, Literature survey-based approach. Analysis of human error types and performance shaping factors is analysis of three human errors. The results of project can be used for task analysis, evaluation of human error probabilities, and analysis of performance shaping factors in the HRA analysis

System analysis for material control and accountancy technology

International Nuclear Information System (INIS)

Persiani, P.J.; Daly, T.A.; Bucher, R.G.; Rothman, A.B.; Cha, B.C.; Trevorrow, L.E.; Seefeldt, W.B.

1987-01-01

The systems analysis for material control and accountancy technology (SAMCAT) program involves a working group structured to ensure that direct operating measurements, accountancy experience, and knowledge of the processes and flows of nuclear material in the total US Department of Energy (DOE) complex of production fuel cycles would be the major bases for developing and implementing a plan of action. This working group consists of facility operators, DOE Office of Safeguards Security headquarters and field offices, and government laboratories. The program focus is to develop a system for decision support in validating the material control and accountancy (MC ampersand A) aspects of the masters safeguards and security agreements effectiveness and in evaluating proposed MC ampersand A upgrades. This paper is a status report on the current capabilities of the system

Dynamic Modeling, Model-Based Control, and Optimization of Solid Oxide Fuel Cells

Science.gov (United States)

Spivey, Benjamin James

2011-07-01

Solid oxide fuel cells are a promising option for distributed stationary power generation that offers efficiencies ranging from 50% in stand-alone applications to greater than 80% in cogeneration. To advance SOFC technology for widespread market penetration, the SOFC should demonstrate improved cell lifetime and load-following capability. This work seeks to improve lifetime through dynamic analysis of critical lifetime variables and advanced control algorithms that permit load-following while remaining in a safe operating zone based on stress analysis. Control algorithms typically have addressed SOFC lifetime operability objectives using unconstrained, single-input-single-output control algorithms that minimize thermal transients. Existing SOFC controls research has not considered maximum radial thermal gradients or limits on absolute temperatures in the SOFC. In particular, as stress analysis demonstrates, the minimum cell temperature is the primary thermal stress driver in tubular SOFCs. This dissertation presents a dynamic, quasi-two-dimensional model for a high-temperature tubular SOFC combined with ejector and prereformer models. The model captures dynamics of critical thermal stress drivers and is used as the physical plant for closed-loop control simulations. A constrained, MIMO model predictive control algorithm is developed and applied to control the SOFC. Closed-loop control simulation results demonstrate effective load-following, constraint satisfaction for critical lifetime variables, and disturbance rejection. Nonlinear programming is applied to find the optimal SOFC size and steady-state operating conditions to minimize total system costs.

Integrated tools for control-system analysis

Science.gov (United States)

Ostroff, Aaron J.; Proffitt, Melissa S.; Clark, David R.

1989-01-01

The basic functions embedded within a user friendly software package (MATRIXx) are used to provide a high level systems approach to the analysis of linear control systems. Various control system analysis configurations are assembled automatically to minimize the amount of work by the user. Interactive decision making is incorporated via menu options and at selected points, such as in the plotting section, by inputting data. There are five evaluations such as the singular value robustness test, singular value loop transfer frequency response, Bode frequency response, steady-state covariance analysis, and closed-loop eigenvalues. Another section describes time response simulations. A time response for random white noise disturbance is available. The configurations and key equations used for each type of analysis, the restrictions that apply, the type of data required, and an example problem are described. One approach for integrating the design and analysis tools is also presented.

Quality Control Procedure Based on Partitioning of NMR Time Series

Directory of Open Access Journals (Sweden)

Michał Staniszewski

2018-03-01

Full Text Available The quality of the magnetic resonance spectroscopy (MRS depends on the stability of magnetic resonance (MR system performance and optimal hardware functioning, which ensure adequate levels of signal-to-noise ratios (SNR as well as good spectral resolution and minimal artifacts in the spectral data. MRS quality control (QC protocols and methodologies are based on phantom measurements that are repeated regularly. In this work, a signal partitioning algorithm based on a dynamic programming (DP method for QC assessment of the spectral data is described. The proposed algorithm allows detection of the change points—the abrupt variations in the time series data. The proposed QC method was tested using the simulated and real phantom data. Simulated data were randomly generated time series distorted by white noise. The real data were taken from the phantom quality control studies of the MRS scanner collected for four and a half years and analyzed by LCModel software. Along with the proposed algorithm, performance of various literature methods was evaluated for the predefined number of change points based on the error values calculated by subtracting the mean values calculated for the periods between the change-points from the original data points. The time series were checked using external software, a set of external methods and the proposed tool, and the obtained results were comparable. The application of dynamic programming in the analysis of the phantom MRS data is a novel approach to QC. The obtained results confirm that the presented change-point-detection tool can be used either for independent analysis of MRS time series (or any other or as a part of quality control.

Constitution of a centralised data base for the internal quality control in radiotherapy; Constitution d'une base de donnees centralisee pour le controle de qualite interne en radiotherapie

Energy Technology Data Exchange (ETDEWEB)

Fau, P.; Rodrigues, C.; Ruchaud, R.; Bravetti, J. [Centre Prive de Radiotherapie de Metz, 57 - Metz (France)

2009-10-15

The objective of this project was to implement a centralised data base of internal quality control in radiotherapy according to the criteria of the decree of A.f.s.s.a.p.s. (French agency of sanitary safety of health products on 27 july 2007, about the internal quality control of external radiotherapy facilities. The software on one year meets the objectives: compliance by comparison with A.f.s.s.a.p.s. criteria but particularly optimization of the centralisation and analysis of the internal quality controls. (N.C.)

Coupling effect and control strategies of the maglev dual-stage inertially stabilization system based on frequency-domain analysis.

Science.gov (United States)

Lin, Zhuchong; Liu, Kun; Zhang, Li; Zeng, Delin

2016-09-01

Maglev dual-stage inertially stabilization (MDIS) system is a newly proposed system which combines a conventional two-axis gimbal assembly and a 5-DOF (degree of freedom) magnetic bearing with vernier tilting capacity to perform dual-stage stabilization for the LOS of the suspended optical instrument. Compared with traditional dual-stage system, maglev dual-stage system exhibits different characteristics due to the negative position stiffness of the magnetic forces, which introduces additional coupling in the dual stage control system. In this paper, the coupling effect on the system performance is addressed based on frequency-domain analysis, including disturbance rejection, fine stage saturation and coarse stage structural resonance suppression. The difference between various control strategies is also discussed, including pile-up(PU), stabilize-follow (SF) and stabilize-compensate (SC). A number of principles for the design of a maglev dual stage system are proposed. A general process is also suggested, which leads to a cost-effective design striking a balance between high performance and complexity. At last, a simulation example is presented to illustrate the arguments in the paper. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Adaptive control of a Stewart platform-based manipulator

Science.gov (United States)

Nguyen, Charles C.; Antrazi, Sami S.; Zhou, Zhen-Lei; Campbell, Charles E., Jr.

1993-01-01

A joint-space adaptive control scheme for controlling noncompliant motion of a Stewart platform-based manipulator (SPBM) was implemented in the Hardware Real-Time Emulator at Goddard Space Flight Center. The six-degrees of freedom SPBM uses two platforms and six linear actuators driven by dc motors. The adaptive control scheme is based on proportional-derivative controllers whose gains are adjusted by an adaptation law based on model reference adaptive control and Liapunov direct method. It is concluded that the adaptive control scheme provides superior tracking capability as compared to fixed-gain controllers.

UDE-based control of variable-speed wind turbine systems

Science.gov (United States)

Ren, Beibei; Wang, Yeqin; Zhong, Qing-Chang

2017-01-01

In this paper, the control of a PMSG (permanent magnet synchronous generator)-based variable-speed wind turbine system with a back-to-back converter is considered. The uncertainty and disturbance estimator (UDE)-based control approach is applied to the regulation of the DC-link voltage and the control of the RSC (rotor-side converter) and the GSC (grid-side converter). For the rotor-side controller, the UDE-based vector control is developed for the RSC with PMSG control to facilitate the application of the MPPT (maximum power point tracking) algorithm for the maximum wind energy capture. For the grid-side controller, the UDE-based vector control is developed to control the GSC with the power reference generated by a UDE-based DC-link voltage controller. Compared with the conventional vector control, the UDE-based vector control can achieve reliable current decoupling control with fast response. Moreover, the UDE-based DC-link voltage regulation can achieve stable DC-link voltage under model uncertainties and external disturbances, e.g. wind speed variations. The effectiveness of the proposed UDE-based control approach is demonstrated through extensive simulation studies in the presence of coupled dynamics, model uncertainties and external disturbances under varying wind speeds. The UDE-based control is able to generate more energy, e.g. by 5% for the wind profile tested.

Integrated Rudder/Fin Concise Control Based on Frequency Domain Analysis

OpenAIRE

W. Guan; Z. J. Su; G. Q. Zhang

2013-01-01

This paper describes a concise robust controller design of integrated rudder and fin control system in use of the closed loop gain shaping algorithm (CGSA) strategy. Compared with the arbitrary selection of weighting function in integrated rudder and fin H∞ mixed sensitivity control design procedures, the CGSA methods provided a relatively more straightforward and concise design method. Simulations were described that the overall performance of each CGSA rudder and fin control loop and the in...

Observer-based leader-following tracking control under both fixed and switching topologies

Institute of Scientific and Technical Information of China (English)

Jinhuan WANG; Pengxiao ZHANG; Zhixin LIU; Xiaoming HU

2016-01-01

This paper studies the tracking problem for a class of leader-follower multi-agent systems moving on the plane using observer-based cooperative control strategies. In our set-up, only a subset of the followers can obtain some relative information on the leader. We assume that the control input of the leader is not known to any of the followers while the system matrix is broadcast to all the followers. To track such a leader, an observer-based decentralized feedback controller is designed for each follower and detailed analysis for the convergence is presented for both fixed and switching interaction topologies between agents with the method of common Lyapunov function. We can also generalize the result to the higher dimension case for fixed topology and some special system matrices of the leader for switching topology.

Sliding mode control-based linear functional observers for discrete-time stochastic systems

Science.gov (United States)

Singh, Satnesh; Janardhanan, Sivaramakrishnan

2017-11-01

Sliding mode control (SMC) is one of the most popular techniques to stabilise linear discrete-time stochastic systems. However, application of SMC becomes difficult when the system states are not available for feedback. This paper presents a new approach to design a SMC-based functional observer for discrete-time stochastic systems. The functional observer is based on the Kronecker product approach. Existence conditions and stability analysis of the proposed observer are given. The control input is estimated by a novel linear functional observer. This approach leads to a non-switching type of control, thereby eliminating the fundamental cause of chatter. Furthermore, the functional observer is designed in such a way that the effect of process and measurement noise is minimised. Simulation example is given to illustrate and validate the proposed design method.

An Analysis of Delay-based and Integrator-based Sequence Detectors for Grid-Connected Converters

DEFF Research Database (Denmark)

Khazraj, Hesam; Silva, Filipe Miguel Faria da; Bak, Claus Leth

2017-01-01

-signal cancellation operators are the main members of the delay-based sequence detectors. The aim of this paper is to provide a theoretical and experimental comparative study between integrator and delay based sequence detectors. The theoretical analysis is conducted based on the small-signal modelling......Detecting and separating positive and negative sequence components of the grid voltage or current is of vital importance in the control of grid-connected power converters, HVDC systems, etc. To this end, several techniques have been proposed in recent years. These techniques can be broadly...... classified into two main classes: The integrator-based techniques and Delay-based techniques. The complex-coefficient filter-based technique, dual second-order generalized integrator-based method, multiple reference frame approach are the main members of the integrator-based sequence detector and the delay...

Cations analysis by controlled potential coulometry. Pt. 2. Zirconium and thorium determination

International Nuclear Information System (INIS)

Harto Castano, A.; Sanchez Batanero, P.

1982-01-01

A controlled-potential coulometry method for determination of zirconium and thorium has been carried out. This method is based on the reduction of potassium ferricyanide in presence of zirconium and thorium ions in acidic media. Stoechiometric coefficients of the solid products have been determined by intensity-controlled coulometry and chemical analysis. Application range and accuracy of the coulometric method has been established and applied to determination of Zr(IV) and Th(IV) in ores [fr

Developments in data acquisition systems with LabView datalogging and supervisory control module for tritium removal plant, with data base and process analysis

International Nuclear Information System (INIS)

Moraru, Carmen Maria; Stefan, Iuliana; Balteanu, Ovidiu; Stefan, Liviu; Bucur, Ciprian; Hartescu, Florin

2006-01-01

Full text: The implementation of the new trends for tritium processing nuclear plants, and especially those with an experimental character or of new technology development, shows a very high complexity due to issues raised by the integration of a high diversity of instrumentation and equipment into a unitary control system of the technological process. Keeping the system's flexibility is a demand of the experimental plants for which the change of configuration, process and parameters is something usual. The big amount of data that needs to be monitored, stored and accessed for ulterior analyses demands the achievement of an information network where the data acquiring, control and analysis systems of the technological process can be integrated with a data base system. Thus, integrated computing and control systems needed for the control of the technological process will be executed, to be continued with the execution of failure protection system, by choosing methods corresponding to the technological processes within the tritium processing nuclear plants. (authors)

Task Analysis Assessment on Intrastate Bus Traffic Controllers

Science.gov (United States)

Yen Bin, Teo; Azlis-Sani, Jalil; Nur Annuar Mohd Yunos, Muhammad; Ismail, S. M. Sabri S. M.; Tajedi, Noor Aqilah Ahmad

2016-11-01

Public transportation acts as social mobility and caters the daily needs of the society for passengers to travel from one place to another. This is true for a country like Malaysia where international trade has been growing significantly over the past few decades. Task analysis assessment was conducted with the consideration of cognitive ergonomic view towards problem related to human factors. Conducting research regarding the task analysis on bus traffic controllers had allowed a better understanding regarding the nature of work and the overall monitoring activities of the bus services. This paper served to study the task analysis assessment on intrastate bus traffic controllers and the objectives of this study include to conduct task analysis assessment on the bus traffic controllers. Task analysis assessment for the bus traffic controllers was developed via Hierarchical Task Analysis (HTA). There are a total of five subsidiary tasks on level one and only two were able to be further broken down in level two. Development of HTA allowed a better understanding regarding the work and this could further ease the evaluation of the tasks conducted by the bus traffic controllers. Thus, human error could be reduced for the safety of all passengers and increase the overall efficiency of the system. Besides, it could assist in improving the operation of the bus traffic controllers by modelling or synthesizing the existing tasks if necessary.

Game-based digital interventions for depression therapy: a systematic review and meta-analysis.

Science.gov (United States)

Li, Jinhui; Theng, Yin-Leng; Foo, Schubert

2014-08-01

The aim of this study was to review the existing literature on game-based digital interventions for depression systematically and examine their effectiveness through a meta-analysis of randomized controlled trials (RCTs). Database searching was conducted using specific search terms and inclusion criteria. A standard meta-analysis was also conducted of available RCT studies with a random effects model. The standard mean difference (Cohen's d) was used to calculate the effect size of each study. Nineteen studies were included in the review, and 10 RCTs (eight studies) were included in the meta-analysis. Four types of game interventions-psycho-education and training, virtual reality exposure therapy, exercising, and entertainment-were identified, with various types of support delivered and populations targeted. The meta-analysis revealed a moderate effect size of the game interventions for depression therapy at posttreatment (d=-0.47 [95% CI -0.69 to -0.24]). A subgroup analysis showed that interventions based on psycho-education and training had a smaller effect than those based on the other forms, and that self-help interventions yielded better outcomes than supported interventions. A higher effect was achieved when a waiting list was used as the control. The review and meta-analysis support the effectiveness of game-based digital interventions for depression. More large-scale, high-quality RCT studies with sufficient long-term data for treatment evaluation are needed.

Theory-based self-management educational interventions on patients with type 2 diabetes: a systematic review and meta-analysis of randomized controlled trials.

Science.gov (United States)

Zhao, Fang-Fang; Suhonen, Riitta; Koskinen, Sanna; Leino-Kilpi, Helena

2017-04-01

To synthesize the effects of theory-based self-management educational interventions on patients with type 2 diabetes (T2DM) in randomized controlled trials. Type 2 diabetes is a common chronic disease causing complications that put a heavy burden on society and reduce the quality of life of patients. Good self-management of diabetes can prevent complications and improve the quality of life of T2DM patients. Systematic review with meta-analysis of randomized controlled trials following Cochrane methods. A literature search was carried out in the MEDLINE, EMBASE, CINAHL, PSYCINFO, and Web of Science databases (1980-April 2015). The risk of bias of these eligible studies was assessed independently by two authors using the Cochrane Collaboration's tool. The Publication bias of the main outcomes was examined. Statistical heterogeneity and random-effects model were used for meta-analysis. Twenty studies with 5802 participants met the inclusion criteria. The interventions in the studies were based on one or more theories which mostly belong to mid-range theories. The pooled main outcomes by random-effects model showed significant improvements in HbA1c, self-efficacy, and diabetes knowledge, but not in BMI. As for quality of life, no conclusions can be drawn as the pooled outcome became the opposite with reduced heterogeneity after one study was excluded. No significant publication bias was found in the main outcomes. To get theory-based interventions to produce more effects, the role of patients should be more involved and stronger and the education team should be trained beyond the primary preparation for the self-management education program. © 2016 John Wiley & Sons Ltd.

Research on Air Quality Evaluation based on Principal Component Analysis

Science.gov (United States)

Wang, Xing; Wang, Zilin; Guo, Min; Chen, Wei; Zhang, Huan

2018-01-01

Economic growth has led to environmental capacity decline and the deterioration of air quality. Air quality evaluation as a fundamental of environmental monitoring and air pollution control has become increasingly important. Based on the principal component analysis (PCA), this paper evaluates the air quality of a large city in Beijing-Tianjin-Hebei Area in recent 10 years and identifies influencing factors, in order to provide reference to air quality management and air pollution control.

COLLABORATIVE TRIAL AND QUALITY CONTROL IN CHEMICAL ANALYSIS

Directory of Open Access Journals (Sweden)

Narsito Narsito

2010-06-01

Full Text Available Abstract                                                             This paper deals with some practical problems related to the quality of analytical chemical data usually met in practice. Special attention is given to the topic of quality control in analytical chemistry, since analytical data is one of the primary information from which some important scientifically based decision are to be made. The present paper starts with brief description on some fundamental aspects associated with quality of analytical data, such as sources of variation of analytical data, criteria for quality of analytical method, quality assurance in chemical analysis. The assessment of quality parameter for analytical method like the use of standard materials as well as standard methods is given. Concerning with the quality control of analytical data, the use of several techniques, such as control samples and control charts, in monitoring analytical data in quality control program are described qualitatively.  In the final part of this paper, some important remarks for the preparation of collaborative trials, including the evaluation of accuracy and reproducibility of analytical method are also given Keywords: collaborative trials, quality control, analytical data Abstract                                                             This paper deals with some practical problems related to the quality of analytical chemical data usually met in practice. Special attention is given to the topic of quality control in analytical chemistry, since analytical data is one of the primary information from which some important scientifically based decision are to be made. The present paper starts with brief description on some fundamental aspects associated with quality of analytical data, such as sources of variation of analytical data, criteria for quality of

SURFACE TEXTURE ANALYSIS FOR FUNCTIONALITY CONTROL

DEFF Research Database (Denmark)

De Chiffre, Leonardo; Andreasen, Jan Lasson; Tosello, Guido

This document is used in connection with three exercises of 3 hours duration as a part of the course VISION ONLINE – One week course on Precision & Nanometrology. The exercises concern surface texture analysis for functionality control, in connection with three different case stories. This docume...... contains a short description of each case story, 3-D roughness parameters analysis and relation with the product’s functionality.......This document is used in connection with three exercises of 3 hours duration as a part of the course VISION ONLINE – One week course on Precision & Nanometrology. The exercises concern surface texture analysis for functionality control, in connection with three different case stories. This document...

Walking dynamics of the passive compass-gait model under OGY-based control: Emergence of bifurcations and chaos

Science.gov (United States)

Gritli, Hassène; Belghith, Safya

2017-06-01

An analysis of the passive dynamic walking of a compass-gait biped model under the OGY-based control approach using the impulsive hybrid nonlinear dynamics is presented in this paper. We describe our strategy for the development of a simplified analytical expression of a controlled hybrid Poincaré map and then for the design of a state-feedback control. Our control methodology is based mainly on the linearization of the impulsive hybrid nonlinear dynamics around a desired nominal one-periodic hybrid limit cycle. Our analysis of the controlled walking dynamics is achieved by means of bifurcation diagrams. Some interesting nonlinear phenomena are displayed, such as the period-doubling bifurcation, the cyclic-fold bifurcation, the period remerging, the period bubbling and chaos. A comparison between the raised phenomena in the impulsive hybrid nonlinear dynamics and the hybrid Poincaré map under control was also presented.

Implementing Discretionary Access Control with Time Character in Linux and Performance Analysis

Institute of Scientific and Technical Information of China (English)

TAN Liang; ZHOU Ming-Tian

2006-01-01

DAC (Discretionary Access Control Policy) is access control based on ownership relations between subject and object, the subject can discretionarily decide on that who, by what methods, can access his owns object. In this paper, the system time is looked as a basic secure element. The DAC_T (Discretionary Access Control Policy with Time Character) is presented and formalized. The DAC_T resolves that the subject can discretionarily decide that who, on when, can access his owns objects. And then the DAC_T is implemented on Linux based on GFAC (General Framework for Access Control), and the algorithm is put forward. Finally, the performance analysis for the DAC_T_Linux is carried out. It is proved that the DAC_T_Linux not only can realize time constraints between subject and object but also can still be accepted by us though its performance have been decreased.

Small-Signal Analysis of the Microgrid Secondary Control Considering a Communication Time Delay

DEFF Research Database (Denmark)

Coelho, Ernane Antônio Alves; Wu, Dan; Guerrero, Josep M.

2016-01-01

This paper presents a small-signal analysis of an islanded microgrid composed of two or more voltage-source inverters connected in parallel. The primary control of each inverter is integrated through an internal current and voltage loops using proportional resonant compensators, a virtual impedance......, and an external power controller based on frequency and voltage droops. The frequency restoration function is implemented at the secondary control level, which executes a consensus algorithm that consists of a load-frequency control and a single time delay communication network. The consensus network consists...... the behavior of the system considering control parameters and time delay variation....

Control and EMS of a Grid-Connected Microgrid with Economical Analysis

Directory of Open Access Journals (Sweden)

Mohamed El-Hendawi

2018-01-01

Full Text Available Recently, significant development has occurred in the field of microgrid and renewable energy systems (RESs. Integrating microgrids and renewable energy sources facilitates a sustainable energy future. This paper proposes a control algorithm and an optimal energy management system (EMS for a grid-connected microgrid to minimize its operating cost. The microgrid includes photovoltaic (PV, wind turbine (WT, and energy storage systems (ESS. The interior search algorithm (ISA optimization technique determines the optimal hour-by-hour scheduling for the microgrid system, while it meets the required load demand based on 24-h ahead forecast data. The control system consists of three stages: EMS, supervisory control and local control. EMS is responsible for providing the control system with the optimum day-ahead scheduling power flow between the microgrid (MG sources, batteries, loads and the main grid based on an economic analysis. The supervisory control stage is responsible for compensating the mismatch between the scheduled power and the real microgrid power. In addition, this paper presents the local control design to regulate the local power, current and DC voltage of the microgrid. For verification, the proposed model was applied on a real case study in Oshawa (Ontario, Canada with various load conditions.

Model-based accelerator controls: What, why and how

International Nuclear Information System (INIS)

Sidhu, S.S.

1987-01-01

Model-based control is defined as a gamut of techniques whose aim is to improve the reliability of an accelerator and enhance the capabilities of the operator, and therefore of the whole control system. The aim of model-based control is seen as gradually moving the function of model-reference from the operator to the computer. The role of the operator in accelerator control and the need for and application of model-based control are briefly summarized

Risk-based configuration control: Application of PSA in improving technical specifications and operational safety

International Nuclear Information System (INIS)

Samanta, P.K.; Kim, I.S.; Vesely, W.E.

1992-01-01

Risk-based configuration control is the management of component configurations using a risk perspective to control risk and assure safety. A configuration, as used here, is a set of component operability statuses that define the state of a nuclear power plant. If the component configurations that have high risk implications do not occur, then the risk from the operation of nuclear power plants would be minimal. The control of component configurations, i.e., the management of component statuses, to minimize the risk from components being unavailable, becomes difficult, because the status of a standby safety system component is often not apparent unless it is tested. Controlling plant configuration from a risk-perspective can provide more direct risk control and also more operational flexibility by allowing looser controls in areas unimportant to risk. Risk-based configuration control approaches can be used to replace parts of nuclear power plant Technical Specifications. With the advances in probabilistic safety assessment (PSA) technology, such approaches to improve Technical Specifications and operational safety are feasible. In this paper, we present an analysis of configuration risks, and a framework for risk-based configuration control to achieve the desired control of risk-significant configurations during plant operation

Observability analysis for model-based fault detection and sensor selection in induction motors

International Nuclear Information System (INIS)

Nakhaeinejad, Mohsen; Bryant, Michael D

2011-01-01

Sensors in different types and configurations provide information on the dynamics of a system. For a specific task, the question is whether measurements have enough information or whether the sensor configuration can be changed to improve the performance or to reduce costs. Observability analysis may answer the questions. This paper presents a general algorithm of nonlinear observability analysis with application to model-based diagnostics and sensor selection in three-phase induction motors. A bond graph model of the motor is developed and verified with experiments. A nonlinear observability matrix based on Lie derivatives is obtained from state equations. An observability index based on the singular value decomposition of the observability matrix is obtained. Singular values and singular vectors are used to identify the most and least observable configurations of sensors and parameters. A complex step derivative technique is used in the calculation of Jacobians to improve the computational performance of the observability analysis. The proposed algorithm of observability analysis can be applied to any nonlinear system to select the best configuration of sensors for applications of model-based diagnostics, observer-based controller, or to determine the level of sensor redundancy. Observability analysis on induction motors provides various sensor configurations with corresponding observability indices. Results show the redundancy levels for different sensors, and provide a sensor selection guideline for model-based diagnostics, and for observer-based controllers. The results can also be used for sensor fault detection and to improve the reliability of the system by increasing the redundancy level in measurements

Safety analysis of control rod drive computers

International Nuclear Information System (INIS)

Ehrenberger, W.; Rauch, G.; Schmeil, U.; Maertz, J.; Mainka, E.U.; Nordland, O.; Gloee, G.

1985-01-01

The analysis of the most significant user programmes revealed no errors in these programmes. The evaluation of approximately 82 cumulated years of operation demonstrated that the operating system of the control rod positioning processor has a reliability that is sufficiently good for the tasks this computer has to fulfil. Computers can be used for safety relevant tasks. The experience gained with the control rod positioning processor confirms that computers are not less reliable than conventional instrumentation and control system for comparable tasks. The examination and evaluation of computers for safety relevant tasks can be done with programme analysis or statistical evaluation of the operating experience. Programme analysis is recommended for seldom used and well structured programmes. For programmes with a long, cumulated operating time a statistical evaluation is more advisable. The effort for examination and evaluation is not greater than the corresponding effort for conventional instrumentation and control systems. This project has also revealed that, where it is technologically sensible, process controlling computers or microprocessors can be qualified for safety relevant tasks without undue effort. (orig./HP) [de

Inventory Control System for a Healthcare Apparel Service Centre with Stockout Risk: A Case Analysis

Directory of Open Access Journals (Sweden)

An Pan

2017-01-01

Full Text Available Based on the real-world inventory control problem of a capacitated healthcare apparel service centre in Hong Kong which provides tailor-made apparel-making services for the elderly and disabled people, this paper studies a partial backordered continuous review inventory control problem in which the product demand follows a Poisson process with a constant lead time. The system is controlled by an (Q,r inventory policy which incorporate the stockout risk, storage capacity, and partial backlog. The healthcare apparel service centre, under the capacity constraint, aims to minimize the inventory cost and achieving a low stockout risk. To address this challenge, an optimization problem is constructed. A real case-based data analysis is conducted, and the result shows that the expected total cost on an order cycle is reduced substantially at around 20% with our proposed optimal inventory control policy. An extensive sensitivity analysis is conducted to generate additional insights.

Safety critical FPGA-based NPP instrumentation and control systems: assessment, development and implementation

International Nuclear Information System (INIS)

Bakhmach, E. S.; Siora, A. A.; Tokarev, V. I.; Kharchenko, V. S.; Sklyar, V. V.; Andrashov, A. A.

2010-10-01

The stages of development, production, verification, licensing and implementation methods and technologies of safety critical instrumentation and control systems for nuclear power plants (NPP) based on FPGA (Field Programmable Gates Arrays) technologies are described. A life cycle model and multi-version technologies of dependability and safety assurance of FPGA-based instrumentation and control systems are discussed. An analysis of NPP instrumentation and control systems construction principles developed by Research and Production Corporation Radiy using FPGA-technologies and results of these systems implementation and operation at Ukrainian and Bulgarian NPP are presented. The RADIY TM platform has been designed and developed by Research and Production Corporation Radiy, Ukraine. The main peculiarity of the RADIY TM platform is the use of FPGA as programmable components for logic control operation. The FPGA-based RADIY TM platform used for NPP instrumentation and control systems development ensures sca lability of system functions types, volume and peculiarities (by changing quantity and quality of sensors, actuators, input/output signals and control algorithms); sca lability of dependability (safety integrity) (by changing a number of redundant channel, tiers, diagnostic and reconfiguration procedures); sca lability of diversity (by changing types, depth and method of diversity selection). (Author)

Spectroscopic analysis technique for arc-welding process control

Science.gov (United States)

Mirapeix, Jesús; Cobo, Adolfo; Conde, Olga; Quintela, María Ángeles; López-Higuera, José-Miguel

2005-09-01

The spectroscopic analysis of the light emitted by thermal plasmas has found many applications, from chemical analysis to monitoring and control of industrial processes. Particularly, it has been demonstrated that the analysis of the thermal plasma generated during arc or laser welding can supply information about the process and, thus, about the quality of the weld. In some critical applications (e.g. the aerospace sector), an early, real-time detection of defects in the weld seam (oxidation, porosity, lack of penetration, ...) is highly desirable as it can reduce expensive non-destructive testing (NDT). Among others techniques, full spectroscopic analysis of the plasma emission is known to offer rich information about the process itself, but it is also very demanding in terms of real-time implementations. In this paper, we proposed a technique for the analysis of the plasma emission spectrum that is able to detect, in real-time, changes in the process parameters that could lead to the formation of defects in the weld seam. It is based on the estimation of the electronic temperature of the plasma through the analysis of the emission peaks from multiple atomic species. Unlike traditional techniques, which usually involve peak fitting to Voigt functions using the Levenberg-Marquardt recursive method, we employ the LPO (Linear Phase Operator) sub-pixel algorithm to accurately estimate the central wavelength of the peaks (allowing an automatic identification of each atomic species) and cubic-spline interpolation of the noisy data to obtain the intensity and width of the peaks. Experimental tests on TIG-welding using fiber-optic capture of light and a low-cost CCD-based spectrometer, show that some typical defects can be easily detected and identified with this technique, whose typical processing time for multiple peak analysis is less than 20msec. running in a conventional PC.

Controlling the accuracy of chemical analysis

International Nuclear Information System (INIS)

Suschny, O.; Danesi, P.R.

1991-01-01

The involvement of the IAEA in quantitative analysis began in the early 1960's with radiochemical work connected with the environment. It than expanded to cover analysis (mostly by nuclear techniques) of samples for projects associated with human health, agriculture, hydrology and international safeguards. This article highlights the IAEA activities in the field of quality control in quantitative analysis

1-D Wavelet Signal Analysis of the Actuators Nonlinearities Impact on the Healthy Control Systems Performance

Directory of Open Access Journals (Sweden)

Nicolae Tudoroiu

2017-09-01

Full Text Available The objective of this paper is to investigate the use of the 1-D wavelet analysis to extract several patterns from signals data sets collected from healthy and faulty input-output signals of control systems as a preliminary step in real-time implementation of fault detection diagnosis and isolation strategies. The 1-D wavelet analysis proved that is an useful tool for signals processing, design and analysis based on wavelet transforms found in a wide range of control systems industrial applications. Based on the fact that in the real life there is a great similitude between the phenomena, we are motivated to extend the applicability of these techniques to solve similar applications from control systems field, such is done in our research work. Their efficiency will be demonstrated on a case study mainly chosen to evaluate the impact of the uncertainties and the nonlinearities of the sensors and actuators on the overall performance of the control systems. The proposed techniques are able to extract in frequency domain some pattern features (signatures of interest directly from the signals data set collected by data acquisition equipment from the control system.

Case-control vaccine effectiveness studies: Data collection, analysis and reporting results.

Science.gov (United States)

Verani, Jennifer R; Baqui, Abdullah H; Broome, Claire V; Cherian, Thomas; Cohen, Cheryl; Farrar, Jennifer L; Feikin, Daniel R; Groome, Michelle J; Hajjeh, Rana A; Johnson, Hope L; Madhi, Shabir A; Mulholland, Kim; O'Brien, Katherine L; Parashar, Umesh D; Patel, Manish M; Rodrigues, Laura C; Santosham, Mathuram; Scott, J Anthony; Smith, Peter G; Sommerfelt, Halvor; Tate, Jacqueline E; Victor, J Chris; Whitney, Cynthia G; Zaidi, Anita K; Zell, Elizabeth R

2017-06-05

The case-control methodology is frequently used to evaluate vaccine effectiveness post-licensure. The results of such studies provide important insight into the level of protection afforded by vaccines in a 'real world' context, and are commonly used to guide vaccine policy decisions. However, the potential for bias and confounding are important limitations to this method, and the results of a poorly conducted or incorrectly interpreted case-control study can mislead policies. In 2012, a group of experts met to review recent experience with case-control studies evaluating vaccine effectiveness; we summarize the recommendations of that group regarding best practices for data collection, analysis, and presentation of the results of case-control vaccine effectiveness studies. Vaccination status is the primary exposure of interest, but can be challenging to assess accurately and with minimal bias. Investigators should understand factors associated with vaccination as well as the availability of documented vaccination status in the study context; case-control studies may not be a valid method for evaluating vaccine effectiveness in settings where many children lack a documented immunization history. To avoid bias, it is essential to use the same methods and effort gathering vaccination data from cases and controls. Variables that may confound the association between illness and vaccination are also important to capture as completely as possible, and where relevant, adjust for in the analysis according to the analytic plan. In presenting results from case-control vaccine effectiveness studies, investigators should describe enrollment among eligible cases and controls as well as the proportion with no documented vaccine history. Emphasis should be placed on confidence intervals, rather than point estimates, of vaccine effectiveness. Case-control studies are a useful approach for evaluating vaccine effectiveness; however careful attention must be paid to the collection

Knowledge-based processing for aircraft flight control

Science.gov (United States)

Painter, John H.; Glass, Emily; Economides, Gregory; Russell, Paul

1994-01-01

This Contractor Report documents research in Intelligent Control using knowledge-based processing in a manner dual to methods found in the classic stochastic decision, estimation, and control discipline. Such knowledge-based control has also been called Declarative, and Hybid. Software architectures were sought, employing the parallelism inherent in modern object-oriented modeling and programming. The viewpoint adopted was that Intelligent Control employs a class of domain-specific software architectures having features common over a broad variety of implementations, such as management of aircraft flight, power distribution, etc. As much attention was paid to software engineering issues as to artificial intelligence and control issues. This research considered that particular processing methods from the stochastic and knowledge-based worlds are duals, that is, similar in a broad context. They provide architectural design concepts which serve as bridges between the disparate disciplines of decision, estimation, control, and artificial intelligence. This research was applied to the control of a subsonic transport aircraft in the airport terminal area.

Digital Printing Quality Detection and Analysis Technology Based on CCD

Science.gov (United States)

He, Ming; Zheng, Liping

2017-12-01

With the help of CCD digital printing quality detection and analysis technology, it can carry out rapid evaluation and objective detection of printing quality, and can play a certain control effect on printing quality. It can be said CDD digital printing quality testing and analysis of the rational application of technology, its digital printing and printing materials for a variety of printing equipments to improve the quality of a very positive role. In this paper, we do an in-depth study and discussion based on the CCD digital print quality testing and analysis technology.

Population-based versus hospital-based controls: are they comparable? Controles poblaciones frente a controles hospitalarios: ¿son comparables?

Directory of Open Access Journals (Sweden)

Alberto Ruano-Ravina

2008-12-01

Full Text Available Objective: To compare whether there are differences among hospital and population controls. Methods: Two case-control studies were conducted on lung cancer risk factors in the Santiago de Compostela Public Health District. Whereas one used randomly chosen census-based population controls, the other used consecutive hospital controls that went to the reference hospital for non-smoking-related trivial interventions. The differences were analyzed using logistic regression. The dependent variable was type of control (hospital or population. Results: Hospital controls had a similar tobacco habit than population controls, but consumed more alcohol. For those consuming more than 50 ml daily, the risk of being a hospital control was 4.83 (95%CI: 2.55-9.14. Conclusions: There may be some differences between hospital and population-based controls, which must be taken into account in the design of case-control studies. It is necessary to ascertain whether such differences are reproduced at other geographic locations and whether they can affect estimation of exposure-disease.Objetivo: Comparar si hay diferencias entre los controles poblacionales y los hospitalarios. Métodos: Se llevaron a cabo dos estudios de casos y controles sobre factores de riesgo de cáncer de pulmón en el Área Sanitaria de Santiago de Compostela. En uno de los estudios los controles fueron seleccionados aleatoriamente entre la población general, y en el otro los controles hospitalarios fueron incluidos de manera consecutiva entre los individuos que acudían al hospital por intervenciones quirúrgicas banales no relacionadas con el consumo de tabaco. Las diferencias fueron analizadas mediante regresión logística. La variable dependiente fue el tipo de control (hospitalario o poblacional. Resultados: Los controles hospitalarios y los poblacionales tenían un hábito tabáquico similar, pero los controles hospitalarios consumían más alcohol. Para los que consumían más de 50 ml

Association between the p53 codon 72 polymorphism and primary open-angle glaucoma risk: Meta-analysis based on 11 case–control studies

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Mohsen Gohari

2016-01-01

Full Text Available The TP53 is important in functions of cell cycle control, apoptosis, and maintenance of DNA integrity. Studies on the association between p53 codon 72 polymorphism and primary open-angle glaucoma (POAG risk have yielded conflicting results. Published literature from PubMed and Web of Science databases was retrieved. All studies evaluating the association between p53 codon 72 polymorphisms and POAG were included. Pooled odds ratio (OR and 95% confidence interval (CI were calculated. Eleven separate studies including 2541 cases and 1844 controls were pooled in the meta-analysis. We did not detect a significant association between POAG risk and p53 codon 72 polymorphism overall population except allele genetic model (C vs. G: OR = 0.961, 95% CI = 0.961–0.820, P = 0.622. In the stratified analysis for Asians and Caucasians, there was an association between p53 codon 72 polymorphism and POAG. In the dominant model in the overall population and by ethnicity subgroups, the highest elevated POAG risk was presented. In summary, these results indicate that p53 codon 72 polymorphism is likely an important genetic factor contributing to susceptibility of POAG. However, more case–controls studies based on larger sample size and stratified by ethnicity are suggested to further clarify the relationship between p53 codon 72 polymorphism and POAG.

Attack Methodology Analysis: Emerging Trends in Computer-Based Attack Methodologies and Their Applicability to Control System Networks

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